bluuebunny/crossref_metadata_2025 huggingface dataset:
Stress-strain characteristics of concrete confined in steel binders
Authors: Sundara Raja Iyengar K. T. , Desayi Prakash , Reddy K. Nagi
Published: July 2012

Synopsis

The ductility of concrete can be increased by confinement in steel binders but, for a proper analysis of the ultimate strength of structures utilizing this gain, an undertsanding of the stress-strain characteristics of confined concrete is necessary. The paper presents the results of axial compression tests on specimens in which the variables were: strength of concrete, size and shape of test specimen and diameter and type of spiral wire. A new factor called the ‘confinement index’ is introduced to define the confinement quantitatively. Ultimate strengths and strains increase with confinement and linearly with the confinement index. Confinement is found to be effective only when the pitch of binders is less than the least lateral dimension of the confined specimen. Of the three types of binder studied—circular spirals, square spirals and stirrups—the first was the most and the last the least effective. The mechanics of the action of steel binders and a similarity between the confining effects of steel binders and of hydrostatic pressure are discussed.
Anchorage zone stresses in post-tensioned uniform members with eccentric and multiple anchorages
Authors: Yettram A. L. , Robbins K.
Published: July 2012

Synopsis

Anchorage zone stresses in post-tensioned members of uniform cross-section are determined by using a finite element procedure for the elastic analysis of three-dimensional solids. Stress distributions are shown for multiple and eccentric anchorages on rectangular and I-section beams. Both bursting and spalling stresses are considered. The results are used to assess the conventional design method of partitioning.
Anchorage zone stresses in axially post-tensioned I-section members with end-blocks
Authors: Yettram A. L. , Robbins K.
Published: July 2012

Synopsis

The stress distributions in the anchorage zone of an I-section member which is axially post-tensioned through an end-block are presented. They have been obtained from finite-element analyses. Three end-block lengths are considered. Comparisons are made betwren the stresses in the members with end-blocks and (a) the section with no end-block (b) the rectangular prismatic beam of which the cross-section is identical with that of the end-block.
A method of detecting and determining lignin compounds in mortars and concretes
Authors: Kroone B.
Published: July 2012

Synopsis

Lignosulphonate and Vinsol-resin type admixtures in concrete are oxidized by precipitated manganese dioxide in caustic soda to produce a high yield of vanillin and other carbonyl products. The products with carbonyl groups react with 2–4 dinitrophenylhydrazine to form brightly coloured osazones and hydrazones, which are quantitatively determined with a spectrophotometer.
The influence of specimen geometry upon weight change and shrinkage of air-dried mortar specimens
Authors: Hobbs D. W. , Mears A. R.
Published: July 2012

Synopsis

Results are given of an investigation into the influence oj specimen size and ‘shape’ upon the weight change and shrinkage of mortar specimens dried at 20°C and 65% R.H. The specimens tested had a water/cement ratio of 0·71 and were moist-cured for 7 days. It is shown that the falling-rate curve may be divided into three periods in which it is suggested that a single mechanism predominates, namely, capillary moisture loss, diffusion moisture loss or carbonation weight gain, and also two intermediate periods in which a combination of two of these three mechanisms gives rise to significant weight changes. The shrinkage measurements are shown to support the division oj the falling-rate curve into a number of periods, and it is shown that the ultimate shrinkage due to moisture loss increases with specimen size. Two methods are suggested for obtaining the ultimate shrinkage of a practical concrete section for which carbonation shrinkage can be assumed to be negligible.
A theoretical investigation of ultimate torque as calculated by truss theory and by the Russian ultimate equilibrium method
Authors: Kuyt B.
Published: July 2012

Synopsis

An analysis is given of the distribution of forces in reinforced concrete elements under pure torsion. It is assumed that the elements are under-reinforced and that failure is initiated by yielding of reinforcement. Two methods of calculation are taken into consideration, the space truss analogy and the ‘ultimate equilibrium method’ as adopted in the Soviet code. It is shown that the latter method will give the same results as the truss theory, provided that proper assumptions are made with respect to the form of the failure surface and the magnitude of the stirrup stresses at the smaller and the larger sides of the beam respectively.
An instability theory of failure for concrete
Authors: Uppal J. Y. , Kemp K. O.
Published: July 2012

Synopsis

A simple mathematical model is proposed in which the failure of concrete under uniaxial compression is attributed to the instability which develops in the macro-elemental structure formed by cracking. The model predicts that there is a critical fracture length which is, with the ultimate stress, dependent upon factors such as size of specimen and longitudinal stress gradient which have previously only been explained by statistical strength theories. The model predictions are compared with the experimental evidence available.
The strain behaviour of concrete in prestressed concrete pressure vessels
Authors: Carmichael G. D. T. , Hornby I. W.
Published: July 2012

Synopsis

At a numher of positions in the top half of the Oldhury ‘A’ prestressed concrete pressure vessel, the total strain has heen calculated from the beginning of prestressing to early 1972 and compared with measurements obtained from vibrating-wire strain gauges. The quantitative significance of the variables which affect the total strain hehaviour of concrete in prestressed concrete pressure vessels is discussed briefly in relation to the calculated and measured strains. The agreement between calculated and measured strains which results from this examination is such that increased confidence can be placed in the results ohtained in calculations of the stresses sustained hy the prestressed concrete pressure vessels operated by the Central Electricity Generating Board.
Short-term stress relaxation of concrete
Authors: Taylor Michael A. , Maurer Gregory K.
Published: July 2012

Synopsis

Concrete cylinders 77 mm in diameter and 270 mm long were subjected to constant strains, and the changes in load (stress relaxation) were monitored for approximately 15 min from the time of loading. The variables examined were: humidity (on dry and saturated specimens); design 28 day strengths (of 13·8, 20·7, 27·6 and 34·5 N/mm2); initial stress levels (20, 40, 60 and 80 % of compressive strength); number of applications (initial and two subsequent loadings); age at loading (40 days and 9 months). Over 100 relaxation tests were performed in which constant strain was maintained by a closed-loop electro-hydraulic testing machine. The principal findings were that short-term stress relaxation may be approximated by a hyperbolic equation, of the type suggested by Ross during studies of creep, and that the behaviour of concrete under constant strain exhibits anomalous features with respect to humidity and water/cement ratio.
Non-elastic deformation of concrete under cyclic compression
Authors: Whaley C. P. , Neville A. M.
Published: July 2012

Synopsis

It is shown that, in comparison with a static stress, cyclic loading accelerates the non-elastic deformation of concrete. The resulting creep can be expressed as the sum of a mean-stress component and of a component which is dependent both upon the range of stress and upon the value of the mean stress.
The Mohr envelope of failure for concrete: a study of its tension-compression part
Authors: Theocaris P. S. , Prassianakis J. N.
Published: July 2012

Synopsis

The purpose of this paper is to study the behaviour of concrete in multiaxial loading in order to construct the failure envelope of the material by tracing the individual Mohr circles for each type of loading. The study was concerned mainly with triaxial loading in longitudinal tension and lateral hydrostatic compression of cylindrical specimens made of a normal type of concrete. Interesting and novel conclusions are revealed for the behaviour of this composite material subject to this type of loading.
Lateral strains in hardened cement paste under short- and long-term loading
Authors: Parrott L. J.
Published: July 2012

Synopsis

The influence of porosity, stress, moisture content, age of loading and period under load upon lateral strains inhardened cement paste under short- and long-term loading is examined. A simple predictive function for Poisson's ratio is given. Creep Poisson's ratio of hardened cement paste was 0·13 for all tests. The relationship between the lateral strain behaviour of hardened cement paste and of concrete is discussed. The creep Poisson's ratio results provided evidence on the nature of the deformation processes in hardened cement paste.
Flexural behaviour of highly converted prestressed high alumina cement concrete beams
Authors: Cusens A. R. , Jackson N.
Published: July 2012

Synopsis

The paper reports the results offlexural tests on highly converted prestressed high alumina cement concrete T beamsfrom schools in Dundee. Owing to the low strength of the concrete, all beams failed in compression. Values of elastic modulus, creep and loss of prestress are estimated from test data and compared with the provisions of CP 110. Recommendations are made regarding appropriate values of elastic modulus and creep.
Measurement of pollen clump release and breakup in the vicinity of ragweed (A. confertiflora) staminate flowers
Authors: Sabban Lilach , Jacobson Neta-lee , van Hout René
Published: July 2012

Pollen dispersal is fundamental in a plant's reproductive ecology and as a result of fragmentation of the landscape, questions have been raised on how isolated plant populations can still exchange genetic information. A common mechanism for gene exchange is wind pollination (anemophily). A successful anemophilous species native to North America is ragweed (Ambrosia), a weed that is hard to eradicate after it takes root on crop fields and its pollen causes very strong allergenic effects (hay fever). Despite the extremely clumpy nature of ragweed pollen that should limit its long distance dispersal, ragweed has spread rapidly across the world during the last century while maintaining a high genetic diversity. One of the reasons for its success may be prolific pollen production as well as an efficient pollen clump release and breakup mechanism. Efficient pollen entrainment and dispersal into the atmosphere is highly influenced by flow field characteristics as pollen released into the atmosphere initially encounters flow structures created by the plant's morphology. Here, the flow field in the wake of a mature ragweed spike having multiple staminate flowers as well as pollen release was studied using Particle Image Velocimetry and high‐speed, inline holographic cinematography. The latter enabled to track the pollen in a 3D volume. The spike was set up in a wind tunnel and exposed to wind speeds ranging from 1 to 2 m/s. Results indicated that ragweed pollen was released in multiple sized clumps containing tens to several thousand single grains. Clumps were both “pulled apart” at the point of entrainment while exiting the flowers as well as broke up in smaller sized clumps in high shear rate flow regions not far from the spike. In addition, the largest clumps that did not travel far, deposited in the vicinity of the spike, breaking apart into many small clumps upon deposition. Based on our results, initial release and dispersal of ragweed pollen clumps is characterized by three concomitant mechanisms of clump breakup occurring at entrainment, in mid‐air and on deposition, which make it perfectly suited to disperse pollen over a wide range of spatial scales.
Neighborhood Disparities in Access to Healthy Foods and Their Effects on Environmental Justice
Authors: Hilmers Angela , Hilmers David C. , Dave Jayna
Published: July 2012

Environmental justice is concerned with an equitable distribution of environmental burdens. These burdens comprise immediate health hazards as well as subtle inequities, such as limited access to healthy foods.

We reviewed the literature on neighborhood disparities in access to fast-food outlets and convenience stores. Low-income neighborhoods offered greater access to food sources that promote unhealthy eating. The distribution of fast-food outlets and convenience stores differed by the racial/ethnic characteristics of the neighborhood.

Further research is needed to address the limitations of current studies, identify effective policy actions to achieve environmental justice, and evaluate intervention strategies to promote lifelong healthy eating habits, optimum health, and vibrant communities.
Fecundity gene linked microsatellite markers in Malabari goats
Authors: Seena T.X. , Raghavan K.C. , Mercy K.A.
Published: July 2012

The DNA samples from 120 Malabari goats were utilized to study the
polymorphism of ovine fecundity genes related microsatellite markers in
goats. A total of 15 alleles with 167-195 bp (base pairs) and 8 alleles with
98-114 bp were observed for loci BM1329 and TGLA68 with polymorphic
information content (PIC) of 0.8526 and 0.7823 respectively. The genotypes
175/185 of BM1329 and 104/106 of TGLA68 were found to be related to a higher
litter size. For the allele 104 bp of TGLA68 highest frequency (0.4545) was
observed in triplets followed by twins (0.2177) and singles (0.1847). The
study indicates the possibilities of using these markers for selection for
high prolificacy in Malabari goats.
The effect of the diet on incidence of footpad lesions and productivity of broilers
Authors: Skrbic Z. , Pavlovski Z. , Lukic M. , Petricevic V. , Miljkovic B. , Marinkov G.
Published: July 2012

Nutrition factors are considered to be very important for incidence of
foot-pad dermatitis through the effect on the quality of litter. Objective of
this study was to investigate the effect of the use of two feeding programs
for broilers available on the market and declared in the
nutritional/economical sense as standard and economical, on quality of
litter, incidence of leg dermatitis (foot-pad and hock burns) and production
performance. Trial was carried out on 500 one day old chickens of Hubbard
genotype, in two treatments and five replicates. Chopped straw was used as
litter. During the trial, the mortality and food consumption were monitored,
and at the end of trial the body mass was controlled, as well as the
incidence of foot-pad and hock burns and their severity were evaluated and
quality of litter analyzed. Research results indicate significant effect of
the diets from the aspect of broiler welfare and productivity. Application of
the feeding program declared in the nutritional/economical sense as
economical resulted in higher content of litter moisture, significantly
higher frequency of incidence of the most severe forms of foot-pad dermatitis
and significantly lower broiler performance.
The effect of full substitution of supplemental methionine with betaine in broiler nutrition on production and slaughter results
Authors: Lukic M. , Jokic Z. , Petricevic V. , Pavlovski Z. , Skrbic Z. , Stojanovic Lj.
Published: July 2012

The use of betaine can influence the resistance, production performance and
quality of broiler carcass, and potentially it can reduce the need for
choline and methionine in food due to the mutual correlation of these three
substances in the organism. Objective of the paper was to investigate the
effect of full substitution of added DL-methionine with betaine in diets for
broilers on production and slaughter parameters in conditions of optimal
amount of choline in the feed. Study was carried out on 1725 one day old
broiler chickens of Cobb 500 hybrid divided into 3 groups: Control group (C)
fed complete forage mixtures with usual addition of DL methionine and two
trial groups where methionine was substituted by 1g (B1group), and by 2g of
betaine per kilogram of mixture (B2 group). Research results indicate that
the full substitution of supplemented methionine with betaine in feed can
have positive and negative impact in broiler fattening. Negative effects on
final body mass, gain and feed conversion were determined in broilers fed
mixtures where 1g of synthetic methionine was replaced with 1g of betaine
preparation, and at the same time positive influence on mortality was
observed, especially in broilers fed diets containing 2g of betaine.
Production index showed no significant differences between trial groups, as
well as studied broiler carcass quality parameters.
The assessment of periodontal health in children age 12 to 15
Authors: Davidovic Bojana , Ivanovic Mirjana , Jankovic Svjetlana , Lecic Jelena
Published: July 2012

Introduction. Periodontal diseases and primarily gingivitis occur relatively
early in the childhood. It was found that 8.8% of children 3-6 years old had
gingivitis and that number increased with age. Gingivitis is especially
common during puberty and mixed dentition. The aim was to determine the
prevalence and characteristics of gingival and periodontal diseases in
children age twelve and fifteen in Republika Srpska. Material and Methods.
The study included 506 students of both genders from six schools on the
territory of the municipalities Foca, Cajnice and Kalinovik. For the
evaluation of oral hygiene and periodontal status, indices suitable for
research in pediatric population were used: Greene-Vermillion Debris Index
(DI), Greene?s Calculus Index (CI), Oral Hygiene Index (OHI) and Community
Periodontal Index of Treatment Needs (CPITN). The evaluation was carried out
in accordance with the criteria for the diagnosis and non- communicable
diseases, established in 1997 in Geneva. Results. The average DI value for
all children was 0.86, the average CI 0.13, and OHI was 0.99. Healthy
periodontium had 14.6% of respondents, while deep periodontal pockets of
4-5mm were found in 8.7% of fifteen-year-old children. Conclusion. A
significant prevalence of gingivitis was found among examined children. It is
necessary to highlight the importance of primary prevention measures, health
education, proper training and regular oral hygiene, as well as regular
check-ups in order to achieve better periodontal health in children.
Recurrent solid ameloblastoma of the maxillary sinus: A case report
Authors: Martins de , Gama de , Guimarães Henriques , Dantas Batista , Bardi Matai , Rangel Rosa
Published: July 2012

Introduction. Ameloblastomas are clinically the most important type of
odontogenic tumors. Solid or multicystic form most commonly affects mandible,
it is highly aggressive and shows high rates of recurrence. The aim was to
report aggressive behavior of a rare maxillary solid ameloblastoma,
emphasizing the clinical, tomographic and histological aspects. Case Report.
A young and asymptomatic patient, presenting a solid ameloblastoma initially
located in the maxillary sinus with rapid spreading to the adjacent tissues,
had early recurrence despite radical surgical approach. Conclusion.
Multicystic or solid ameloblastoma has lower incidence in maxilla and
extremely aggressive behavior, justifying careful follow-up of the patients.
Female Board Presence and the Likelihood of Financial Restatement
Authors: Abbott Lawrence J. , Parker Susan , Presley Theresa J.
Published: July 2012

SYNOPSIS:

This paper investigates the impact of one form of board diversity on the incidence of financial restatement. More specifically, we hypothesize that there is a negative relation between female board presence (defined as whether or not a board has at least one female director) and the likelihood of a financial restatement. Our hypothesis is consistent with a female board presence contributing to the board's ability to maintain an attitude of mental independence, diminishing the extent of groupthink and enhancing the ability of the board to monitor financial reporting. Utilizing the U.S. General Accounting Office (U.S. GAO 2002) report on restatements, we construct a matched-pair sample of 278 annual (187 quarterly) restatement and 278 annual (187 quarterly) control firms. After controlling for other restatement-related factors, we find a significant association between the presence of at least one woman on the board and a lower likelihood of restatement. Our results continue to hold in annual restatements from the post-Sarbanes-Oxley (SOX) time period.
An Examination of the Cost of Capital Implications of FIN 46
Authors: Callahan Carolyn M. , Smith Rodney E. , Spencer Angela Wheeler
Published: July 2012

This study examines whether the adoption in 2003 of FASB Interpretation No. 46/R (FIN 46), Consolidation of Variable Interest Entities—An Interpretation of ARB No. 51, changed the cost of capital for affected firms. Using comparative analysis on a broad sample of 11,719 firm-quarter observations for 1,389 firms during the period 1998 through 2005, we find evidence that FIN 46 significantly increased the cost of equity capital for firms with affected variable interest entities (VIEs), an increase of approximately 50 basis points relative to firms reporting no material effect from the standard. Further, firms consolidating these formerly off-balance sheet structures experienced the largest increase. Taken together, these results suggest that FIN 46 reduced the opportunity for firms to use off-balance sheet structures to artificially reduce their cost of capital, a matter of regulatory concern.

Data Availability: All data are available from public sources.
Re-Examining Anomalous Early Dates of Settlement in Leeward Hawai'i Island
Authors: Carson Mike T
Published: July 2012

Anomalous dates prior to 1000 yr BP have been reported for near-surface site deposits at Puapua'a in the dry and rocky zone of leeward (west) Hawai'i Island, compared to archipelago-wide earliest cultural layers generally in buried contexts 1000–800 yr BP. Redating and closer examination cannot validate these early dates in cultural association. In the thin sedimentary deposits, preserved cultural materials mostly postdate 600–400 yr BP, but some older materials were incorporated into the layer matrix. The results suggest a much shorter extant chronology of human settlement of this particular zone, whereas earliest sites most likely are preserved in different settings of the Hawaiian Islands.
Enteropathogens identified in cats entering a Florida animal shelter with normal feces or diarrhea
Authors: Sabshin Stephanie J. , Levy Julie K. , Tupler Tiffany , Tucker Sylvia J. , Greiner Ellis C. , Leutenegger Christian M.
Published: July 2012

Objective—To determine the frequency of enteropathogens in cats entering an animal shelter with normal feces or diarrhea.

Design—Cross-sectional study.

Animals—100 cats evaluated at an open-admission municipal animal shelter in Florida.

Procedures—Fecal samples collected within 24 hours after admission from 50 cats with normal feces and 50 cats with diarrhea were tested by fecal flotation, antigen testing, PCR assay, and electron microscopy for selected enteropathogens.

Results—12 enteropathogens were identified. Cats with diarrhea were no more likely to be infected with ≥ 1 (84%) enteropathogens than were cats with normal feces (84%). Only feline coronavirus was significantly more prevalent in cats with diarrhea (58%) than in cats with normal feces (36%). Other enteropathogens identified in cats with and without diarrhea included Clostridium perfringens enterotoxin A (42% and 50%, respectively), Cryptosporidium spp (10% and 20%, respectively), Giardia spp (20% and 8%, respectively), Cystoisospora spp (14% and 10%, respectively), hookworms (10% and 18%, respectively), ascarids (6% and 16%, respectively), Salmonella spp (6% and 4%, respectively), astrovirus (8% and 2%, respectively), feline panleukopenia virus (4% and 4%, respectively), calicivirus (0% and 2%, respectively), and Spirometra spp (0% and 2%, respectively).

Conclusions and Clinical Relevance—In the present study, cats entered the shelter with a variety of enteropathogens, many of which are pathogenic or zoonotic. Most infections were not associated with diarrhea or any specific risk factors such as signalment, source, or body condition, making it difficult to predict which cats were most likely to be infected. It is not possible to test all shelter cats for all possible infections, so practical guidelines should be developed to treat routinely for the most common and important enteropathogens.
Frequency of vomiting during the postoperative period in hydromorphone-treated dogs undergoing orthopedic surgery
Authors: Stern Leah C. , Palmisano Matthew P.
Published: July 2012

Objective—To determine the frequency of postoperative vomiting in dogs undergoing routine orthopedic surgery that were treated with hydromorphone and whether that frequency would vary on the basis of administration route.

Design—Noncontrolled clinical trial.

Animals—58 client-owned dogs with cranial cruciate ligament deficiency.

Procedures—Before surgery, all dogs received hydromorphone (0.1 mg/kg [0.045 mg/lb], IM or IV) and 41 dogs also received acepromazine. Anesthesia was induced with diazepam and propofol and maintained with isoflurane in oxygen. Dogs subsequently underwent surgical stabilization of the stifle joint. After surgery, dogs were randomly assigned to receive hydromorphone (0.1 mg/kg) via one of the following routes: IM, IV quickly (for 1 to 2 seconds), or IV slowly (for approx 1 minute). Dogs were monitored for vomiting.

Results—A median of 4 doses of hydromorphone/dog was administered after surgery. One dog was observed to regurgitate once prior to postoperative IM administration of hydromorphone; no dogs vomited at any point during the study period, regardless of the method of hydromorphone administration.

Conclusions and Clinical Relevance—The method of hydromorphone administration had no apparent effect on the likelihood of dogs vomiting. Because no dogs vomited, a particular administration method cannot be recommended. However, findings suggested that hydromorphone can be administered to dogs following orthopedic surgery without a clinically important risk of vomiting or regurgitation.
Ovarian Cancer Stroma: Pathophysiology and the Roles in Cancer Development
Authors: Furuya Mitsuko
Published: July 2012

Ovarian cancer represents one of the cancers with the worst prognostic in adult women. More than half of the patients who present with clinical signs such as abdominal bloating and a feeling of fullness already show advanced stages. The majority of ovarian cancers grow as cystic masses, and cancer cells easily spread into the pelvic cavity once the cysts rupture or leak. When the ovarian cancer cells disseminate into the peritoneal cavity, metastatic nests may grow in the cul-de-sac, and in more advanced stages, the peritoneal surfaces of the upper abdomen become the next largest soil for cancer progression. Ascites is also produced frequently in ovarian cancers, which facilitates distant metastasis. Clinicopathologic, epidemiologic and molecular studies on ovarian cancers have improved our understanding and therapeutic approaches, but still further efforts are required to reduce the risks in the patients who are predisposed to this lethal disease and the mortality of the patients in advanced stages. Among various molecules involved in ovarian carcinogenesis, special genes such as TP53, BRCA1 and BRCA2 have been well investigated. These genes are widely accepted as the predisposing factors that trigger malignant transformation of the epithelial cells of the ovary. In addition, adnexal inflammatory conditions such as chronic salpingitis and ovarian endometriosis have been great research interests in the context of carcinogenic background of ovarian cancers. In this review, I discuss the roles of stromal cells and inflammatory factors in the carcinogenesis and progression of ovarian cancers.
Nonintrusive Energy Monitoring for Microgrids Using Hybrid Self-Organizing Feature-Mapping Networks
Authors: Hong Ying-Yi , Chou Jing-Han
Published: July 2012

Microgrids can increase power penetration from distributed generation (DG) in the power system. The interface (i.e., the point of common coupling, PCC) between the microgrid and the power utility must satisfy certain standards, such as IEEE Sd. 1547. Energy monitoring of the microgrid at the PCC by the power utility is crucial if the utility cannot install advanced meters at different locations in the microgrid (e.g., a factory). This paper presents a new nonintrusive energy monitoring method using a hybrid self-organizing feature-mapping neural network (SOFMNN). The components of the FFT spectra for voltage, current, kW and kVAR, measured at the PCC, serve as the signatures for the hybrid SOFMNN inputs. The nonintrusive energy monitoring at the PCC identifies different load levels for individual linear/nonlinear loads and output levels for wind power generators in the microgrid. Using this energy monitoring result, the power utility can establish an energy management policy. The simulation results from a microgrid, consisting of a diesel generator, a wind-turbine-generator, a rectifier and a cyclo-converter, show the practicability of the proposed method.
A Pulsatile Bioreactor for Conditioning of Tissue-Engineered Cardiovascular Constructs under Endoscopic Visualization
Authors: König Fabian , Hollweck Trixi , Pfeifer Stefan , Reichart Bruno , Wintermantel Erich , Hagl Christian , Akra Bassil
Published: July 2012

Heart valve disease (HVD) is a globally increasing problem and accounts for thousands of deaths yearly. Currently end-stage HVD can only be treated by total valve replacement, however with major drawbacks. To overcome the limitations of conventional substitutes, a new clinical approach based on cell colonization of artificially manufactured heart valves has been developed. Even though this attempt seems promising, a confluent and stable cell layer has not yet been achieved due to the high stresses present in this area of the human heart. This study describes a bioreactor with a new approach to cell conditioning of tissue engineered heart valves. The bioreactor provides a low pulsatile flow that grants the correct opening and closing of the valve without high shear stresses. The flow rate can be regulated allowing a steady and sensitive conditioning process. Furthermore, the correct functioning of the valve can be monitored by endoscope surveillance in real-time. The tubeless and modular design allows an accurate, simple and faultless assembly of the reactor in a laminar flow chamber. It can be concluded that the bioreactor provides a strong tool for dynamic pre-conditioning and monitoring of colonized heart valve prostheses physiologically exposed to shear stress.
The Influence of Estrogens on the Biological and Therapeutic Actions of Growth Hormone in the Liver
Authors: De Mirecki-Garrido Mercedes , Guerra Borja , Mateos-Díaz Carlos , Jiménez-Monzón Roberto , Díaz-Chico Nicolás , Díaz-Chico Juan C. , Fernández-Pérez Leandro
Published: July 2012

GH is main regulator of body growth and composition, somatic development, intermediate metabolism and gender-dependent dimorphism in mammals. The liver is a direct target of estrogens because it expresses estrogen receptors which are connected with development, lipid metabolism and insulin sensitivity, hepatic carcinogenesis, protection from drug-induced toxicity and fertility. In addition, estrogens can modulate GH actions in liver by acting centrally, regulating pituitary GH secretion, and, peripherally, by modulating GHR-JAK2-STAT5 signalling pathway. Therefore, the interactions of estrogens with GH actions in liver are biologically and clinically relevant because disruption of GH signaling may cause alterations of its endocrine, metabolic, and gender differentiated functions and it could be linked to dramatic impact in liver physiology during development as well as in adulthood. Finally, the interplay of estrogens with GH is relevant because physiological roles these hormones have in human, and the widespread exposition of estrogen or estrogen-related compounds in human. This review highlights the importance of these hormones in liver physiology as well as how estrogens modulate GH actions in liver which will help to improve the clinical use of these hormones.
Investigation of Interactive Effects on Water Flow and Solute Transport in Sandy Loam Soil Using Time Domain Reflectometry
Authors: Merdun Hasan
Published: July 2012

Surface-applied chemicals move through the unsaturated zone with complex flow and transport processes due to soil heterogeneity and reach the saturated zone, resulting in groundwater contamination. Such complex processes need to be studied by advanced measurement and modeling techniques to protect soil and water resources from contamination. In this study, the interactive effects of factors like soil structure, initial soil water content (SWC), and application rate on preferential flow and transport were studied in a sandy loam field soil using measurement (by time domain reflectometry (TDR)) and modeling (by MACRO and VS2DTI) techniques. In addition, statistical analyses were performed to compare the means of the measured and modeled SWC and EC, and solute transport parameters (pore water velocity and dispersion coefficient) in 12 treatments. Research results showed that even though the effects of soil structural conditions on water and solute transport were not so clear, the applied solution moved lower depths in the profiles of wet versus dry initial SWC and high application rate versus low application rates. The effects of soil structure and initial SWC on water and solute movement could be differentiated under the interactive conditions, but the effects of the application rates were difficult to differentiate under different soil structural and initial SWC conditions. Modeling results showed that MACRO had somewhat better performance than VS2DTI in the estimation of SWC and EC with space and time, but overall both models had relatively low performances. The means of SWC, EC, and solute transport parameters of the 12 treatments were divided into some groups based on the statistical analyses, indicating different flow and transport characteristics or a certain degree nonuniform or preferential flow and transport in the soil. Conducting field experiments with more interactive factors and applying the models with different approaches may allow better understanding of flow and transport processes in addition to the simulations of them in the unsaturated zone.
Ubiquitous Geo-Sensing for Context-Aware Analysis: Exploring Relationships between Environmental and Human Dynamics
Authors: Sagl Günther , Blaschke Thomas , Beinat Euro , Resch Bernd
Published: July 2012

Ubiquitous geo-sensing enables context-aware analyses of physical and social phenomena, i.e., analyzing one phenomenon in the context of another. Although such context-aware analysis can potentially enable a more holistic understanding of spatio-temporal processes, it is rarely documented in the scientific literature yet. In this paper we analyzed the collective human behavior in the context of the weather. We therefore explored the complex relationships between these two spatio-temporal phenomena to provide novel insights into the dynamics of urban systems. Aggregated mobile phone data, which served as a proxy for collective human behavior, was linked with the weather data from climate stations in the case study area, the city of Udine, Northern Italy. To identify and characterize potential patterns within the weather-human relationships, we developed a hybrid approach which integrates several spatio-temporal statistical analysis methods. Thereby we show that explanatory factor analysis, when applied to a number of meteorological variables, can be used to differentiate between normal and adverse weather conditions. Further, we measured the strength of the relationship between the ‘global’ adverse weather conditions and the spatially explicit effective variations in user-generated mobile network traffic for three distinct periods using the Maximal Information Coefficient (MIC). The analyses result in three spatially referenced maps of MICs which reveal interesting insights into collective human dynamics in the context of weather, but also initiate several new scientific challenges.
Correction: The Unsustainable Trend of Natural Hazard Losses in the United States, Sustainability 2011, 3, 2157-2181
Authors: Gall Melanie , Borden Kevin A. , Emrich Christopher T. , Cutter Susan L.
Published: July 2012

The authors wish to make the following correction to this paper. Due to mislabeling, replace: [...]
A Critical Role for Rictor in T Lymphopoiesis
Authors: Tang Fei , Wu Qi , Ikenoue Tsuneo , Guan Kun-Liang , Liu Yang , Zheng Pan
Published: July 2012

Apart from a critical role for Notch and pre-TCR, the signaling pathway required for T lymphopoiesis is largely unknown. Given the potential link between Notch and mammalian target of rapamycin (mTOR) signaling in cancer cells, we used mice with conditional deletion of either Raptor or Rictor genes to determine potential contribution of the mTOR complex I and II in T lymphopoiesis. Our data demonstrated that targeted mutation of Rictor in the thymocytes drastically reduced the thymic cellularity, primarily by reducing proliferation of the immature thymocytes. Rictor deficiency caused a partial block of thymocyte development at the double-negative 3 stage. The effect of Rictor deficiency is selective for the T cell lineage, as the development of B cells, erythrocytes, and myeloid cells is largely unaffected. Analysis of bone marrow chimera generated from a mixture of wild-type and Rictor-deficient hematopoietic stem cells demonstrated that the function of Rictor is cell intrinsic. These data revealed a critical function of mTOR complex 2 in T lymphopoiesis.
Retention factors in relation to organisational commitment in medical and information technology services
Authors: Van Dyk Jeannette , Coetzee Melinde
Published: July 2012

Orientation: Retaining staff with scarce and critical skills in the medical and information technology (IT) industry has become a top priority because of skills shortages.Research purpose: The objectives of the study were to investigate empirically: (1) the relationship between employees’ satisfaction with organisational retention factors (measured by the Retention Factors Scale) and their organisational commitment (measured by the Organisational Commitment Questionnaire) and (2) whether gender, age, race and tenure groups differ significantly in terms of these variables.Motivation for the study: Medical and information technology professionals have specialised and hard to replace skills. They also have strong tendencies to leave their organisations and countries. Understanding the retention factors that will increase their organisational commitment may benefit the organisations who want to retain their valuable talent.Research design, approach and method: The researchers used a cross-sectional survey design to collect data from a purposive sample of 206 staff members who had scarce skills in a South African medical and information technology services company. Correlational and inferential statistics were computed to achieve the objectives.Main findings: The results showed that the participants’ satisfaction with retention factors has a significant relationship with their organisational commitment and that the biographical groups differ significantly in terms of the variables.Practical/managerial implications: The measured retention factors were all associated with human resource management practices that influence employees’ intentions to leave.Contribution/value-add: The results are important to managers who are interested in retaining staff who have scarce skills and provide valuable pointers for designing effective retention strategies.
The systems psychodynamic experiences of first-year master’s students in industrial and organisational psychology
Authors: Cilliers Frans , Harry Nisha
Published: July 2012

Orientation: The researchers described the experiences of first-year master’s students in industrial and organisational psychology in terms of their anxiety and basic assumption behaviour. Apart from their academic tasks, they seem to be unconsciously involved in many relationship and relatedness matters.Research purpose: The purpose of this research was to describe the systems psychodynamic experiences of first-year master’s students in Industrial and Organisational Psychology.Motivation for the study: Academic staff members tend to forget their own experiences as master’s students, lose touch with their students’ experiences, lose empathy and treat student groups in mechanistic ways. Although the students’ conscious tasks and roles are relatively clear, very little is known about their unconscious experiences.Research design, approach and method: The researchers used qualitative research involving a case study. They collected the data and conducted their analyses by administering a Listening Post (LP) and discourse analysis. Two themes emerged, from which the researchers formulated their working and research hypotheses.Main findings: The themes related to anxiety and basic assumption behaviour. The research hypothesis referred to students’ introjections of emotional incompetence. This resulted in exhaustion.Practical/managerial implications: More focused attention to the students’ emotional experiences, by themselves and by academic staff members, could conserve students’ energy for their academic work and relationships.Contribution/value-add: Being master’s students consumes emotional energy that jeopardises students’ academic work and forming relationships. Being aware of these and managing them could help students to achieve better academically.
Μαρτυρια [witness] in John 1�4: Towards an emerging, missional ecclesiology
Authors: Smit Guillaume H.
Published: July 2012

Theological investigation of the μαρτυρια[witness] lexeme in John 1�4 contributes significantly towards an understanding of an emerging, missional ecclesiology. This hypothesis is precipitated by the accelerated pace of change that our society is currently experiencing. The technological developments of the past 50 years have created a society that is dependent on this new technology, leading to the developing of a new cultural paradigm, in which the church is ill at home. The question of an emerging, missional ecclesiology is therefore building on the need for theological research from the perspective of this developing new paradigm. It was proposed that a hermeneutic approach should be taken. It was also argued that ecclesiology serves as the integration point for reflection and practical missional ministry. As such, the church as object of investigation is the ultimate technological praxis, as the faith community serves as the show-case of God�s presence in this world.
Molecular Species Identification of Candida from Blood Samples of Intensive Care Unit Patients by Polymerase Chain Reaction – Restricted Fragment Length Polymorphism
Authors: Vijayakumar Ramraj , Giri Sidhartha , Kindo Anupma Jyoti
Published: July 2012

Introduction: Candida spp is an emerging cause of blood stream infections worldwide. Delay in speciation of Candida isolates by conventional methods and resistance to antifungal drugs (especially fluconazole, amphotericin B, etc.) in various Candida species are some of the factors responsible for the increase in morbidity and mortality due to candidemia. So, the rapid detection and identification of Candida isolates from blood is very important for the proper management of patients having candidemia.

Materials and Methods: In this study, we have used polymerase chain reaction (PCR) - restriction fragment length polymorphism (RFLP) as a method for the speciation of Candida isolates from blood samples of intensive care unit (ICU) patients. PCR was used to amplify the ITS-1 and ITS-2 regions of Candida spp using universal primers ITS-1 and ITS-4. The amplified product was digested using Msp I restriction enzyme by RFLP.

Results and Discussion: The method PCR-RFLP helped in identifying five medically important Candida spp (C. tropicalis, C. albicans, C. parapsilosis, C. krusei and C. glabrata) from blood. This method is rapid, reliable, easy and cost-effective and can be used in routine laboratory diagnostics for the rapid identification of Candida isolates from blood.

Conclusion: PCR-RFLP is an easy, rapid and highly valuable tool which can be used in routine diagnostic laboratories to speciate Candida isolates obtained from blood. This rapid method of speciation will help clinicians to decide on empirical therapy in candidemia cases before antifungal susceptibility results are available.
Prevalence and Characterization of Diarrheagenic Escherichia coli Isolated from Adults and Children in Mangalore, India
Authors: Shetty Veena A , Kumar Sanath H , Shetty Avinash K , Karunasagar Iddya , Karunasagar Indrani
Published: July 2012

Background: Diarrheal diseases are a major cause of morbidity and mortality in resource-limited countries. Among the bacterial pathogens, diarrheagenic E. coli (DEC) are most frequently implicated in cases of epidemic and endemic diarrhea worldwide. The objective of this study was to determine the prevalence of DEC in stool specimens from patients with acute diarrhea using polymerase chain reaction (PCR).

Materials and Methods: Escherichia coli stool samples were collected from 115 hospitalized children and adults with acute diarrhea in Mangalore, a coastal city, in southern India. PCR amplification of eae, bfp, stx, ehx genes were used for detection of enteropathogenic (EPEC) and shigatoxigenic E. coli (STEC), lt and st genes were used for enterotoxigenic E. coli (ETEC) and astA gene for enteroaggregative E. coli (EAEC).

Results: During the 24 month study period, of the 115 stool samples, DEC type was detected in 20 (17.4%) using the PCR method. The most prevalent DEC was atypical EPEC accounting for 12 (10.4%) cases followed by 4 cases of EAEC (3.4%) and 4 of STEC (3.4%). No ETEC strains were isolated from any of the examined stool samples.

Conclusion: This study suggests that the atypical EPEC are the newly emerging group among DEC stains in Southern India. Further studies are needed to evaluate the epidemiology and virulence properties of atypical EPEC strains.