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Sample records for comparative histomorphometric study

  1. Comparative Evaluation of Two Types of Immediately Loaded Implants Using Biomechanical and Histomorphometric Tests: An Animal Case Study

    PubMed Central

    Rismanchian, Mansour; Movahedian, Bijan; Khalighinejad, Navid; Badrian, Hamid; Mohammad Razavi, Sayed; Nekouie, Afsaneh

    2012-01-01

    Introduction. In order to minimize the required time to regain esthetic and function, immediately loaded implants were suggested. The aim of this study was to comparatively evaluate the Nisastan and XIve implants using biomechanical and histomorphometric tests. Materials and Methods. In this experimental study, 6 Nisastan one-piece immediately loaded screw type implant (OPILS) and 6 Xive implants with 3.4 mm diameter and 11 mm long were used. The implants were immediately loaded with temporary coating. After three months, the torque required to break bone-implant contact was measured and was recorded. All implants were extracted with surrounding bone and histologically were evaluated. The data were inputted into the SPSS 11.5 to run student T-test statistical analyses (α = 0.05). Results. The success rates of both types of implants was 100%, and none of them failed due to mobility or bone loss. The mean removal torque value (RTV) was 142.08 and 40 N/Cm for Xive and Nisastan implants, respectively, and their RTVs showed a significant difference between two mentioned implants (P = 0.004). None of the histomorphometric values showed significant differences between the two implants (P > 0.05). Discussion. both systems have the capability to induce osseointegration under immediate loads but that Xive implants showed higher capability for bone contact. PMID:22852091

  2. Histological and histomorphometrical comparative study of β-tricalcium phosphate block grafts and periosteal expansion osteogenesis for alveolar bone augmentation.

    PubMed

    Yamauchi, K; Takahashi, T; Funaki, K; Hamada, Y; Yamashita, Y

    2010-10-01

    This study evaluated local tissue reaction around the β-tricalcium phosphate (β-TCP) block and compared results with β-TCP block grafting and periosteal expansion osteogenesis (PEO). The mandibular premolars were extracted from five dogs and buccal corticotomy was performed. Narrow alveolar ridge models were created at 4 weeks. The β-TCP block graft, such as veneer graft, was used on the right side and PEO using β-TCP block on the left side. Changes of alveolar width, histological findings and histomorphometrical analysis were evaluated. There were no problems with materials at any of the sites at any time. In both groups, the width increased after surgery and results were stable 8 weeks after surgery. Newly formed bone tissue was observed inside the β-TCP block in both sides. Histological findings differed especially at the division between mandibular bone and β-TCP block. Histomorphometric analyses revealed that β-TCP had been absorbed (mean decrease 28%) and new bone had formed (mean increase 43%) at 8 weeks postoperatively on both sides. The β-TCP block worked as a space-maker under the soft tissue, including the periosteum, and acted as a substitute for original bone. This bone substitute was effective material for bone augmentation in both methods. PMID:20615666

  3. Histomorphometric study to compare histological changes between oral squamous cell carcinoma and apparently normal adjacent oral mucosa.

    PubMed

    Babji, Deepa V; Kale, Alka D; Hallikerimath, Seema R; Kotrashetti, Vijayalakshmi S

    2015-03-01

    Despite the advances in surgery, radiotherapy and chemotherapy the annual death for oral squamous cell carcinoma (OSCC) is rising rapidly. The carcinoma has propensity to develop in a field of cancerization. Clinically may it be apparently normal mucosa (ANM) adjacent to squamous cell carcinoma which harbours certain discrete molecular alteration which ultimately reflects in cellular morphology. Hence the aim of the study is to assess histomorphometric changes in ANM adjacent to OSCC. A prospective study was done on 30 each of histologically diagnosed cases OSCC, ANM at least 1 cm away from OSCC, and normal oral mucosa (NOM). Cellular and nuclear morphometric measurements were assessed on hematoxylin and eosin sections using image analysis software. Statistical analysis was done using analysis of variance test and Tukey's post hoc test. The present study showed significant changes in cellular and nuclear area in superficial and invasive island of OSCC compared to ANM. The basal cells of ANM showed significant decrease in cellular and nuclear areas and nuclear cytoplasmic ratio when compared to NOM. Histomorphometry definitely can differentiate OSCC form ANM and NOM. The basal cells of ANM showed significant alterations in cellular area, nuclear area and nuclear cytoplasmic area when compared to NOM suggesting change in the field and have high risk of malignant transformation. These parameters can be used as indicator of field cancerization. PMID:25621249

  4. Maxillary sinus floor augmentation on humans: Packing simulations and 8 months histomorphometric comparative study of anorganic bone matrix and β-tricalcium phosphate particles as grafting materials

    PubMed Central

    Martinez, A.; Franco, J.; Saiz, E.; Guitian, F.

    2011-01-01

    The present study compares the behaviour of an anorganic bone matrix material and a synthetic β-Tricalcium phosphate employed as grafting materials in a sinus floor augmentation two step protocol in humans. In order to estimate the initial occupation level for the two materials, an ‘in vitro’ simulation has been performed to analyse macroporosity created due to particle packing in terms of porosity and interparticle distances. Grafting in the sinus floor augmentation was performed by filling the defects only with pure grafting materials without autogenous bone addition. The new-bone generated is 100% based on the osteoconductive properties of the grafted materials in contact with physiological fluids. The implants were placed 8 months after the grafting procedure. All the implanted positions were biopsied and embedded in methacrylate resin. Histomorphometric analyses were done over thin film undecalcified sections. Packing simulations allow establishing a comparison of the resorbed volumes related to the initial occupancy of the grafting materials inside the defect. The nature of this interconnected pore network is very alike for either material so new-bone generated was similar (~35 vol.%). PMID:21625341

  5. Comparative study of the effects of laser photobiomodulation and extract of Brassica oleracea on skin wounds in wistar rats: A histomorphometric study.

    PubMed

    Gonçalves, Reggiani Vilela; Sarandy, Mariáurea Matias; da Matta, Sérgio Luis Pinto; Novaes, Rômulo Dias; Pinto, Marcus Vinicius de Mello

    2013-10-01

    The objective of this study was to investigate the effect of a photobiomodulation laser and Brassica oleracea on tissue morphology in skin wounds. The parameters analyzed were type I and III collagen fibers, and thickness and surface density of the epithelial tissue, as well as how quickly the wound closed. Five skin wounds 12mm in diameter were made on the backs of the animals, which were randomized into four groups (8 animals each). Saline Group: 0.9% saline solution; Ointment Group (extract of Cabbage, B. oleracea, 10% lanolin); Balsam Group (10% glycolic extract of B. oleracea emulsion oil); L60 Group (laser GaAsAl 60J/cm(2)). The applications were made daily during a 20-day treatment, and every 4 days tissue from different wounds was removed. The reduction in the size of the wounds on the 4th, 8th, 12th and 16th days was significantly greater in the treated groups compared to the control group. At all the time points analyzed, there was a greater proportion of collagen in the Balsam and L60 groups (p<0.05). There was also a greater proliferation of epithelial cells in the L60 and Balsam groups after 20 days of treatment (p<0.05). The healing extract and laser 60j/cm(2) exerted a great effect on collagen proliferation in stimulating scar tissue maturation. PMID:23968696

  6. Comparing the TiOblast and Osseospeed surfaces. Histomorphometric and histological analysis in humans

    PubMed Central

    ROCCI, M.; ROCCI, A.; MARTIGNONI, M.; ALBREKTSSON, T.; BARLATTANI, A.; GARGARI, M.

    2008-01-01

    SUMMARY The aim of the present study was to compare two implant surfaces, the TiOblast (Astra Tech) surface, manufactured by blasting the surface and already present in literature and the Osseospeed (Astra Tech) surface, manufactured by blasting and treating the surface with fluoride ions and recently launched onto the market with the modified surfaces of the latest generation. This study is part of a more extensive research project whose protocol required the insertion of 10 couples of implants; thus in the present discussion partial data are being taken into consideration, with an eye at collecting more data in the future, regarding both microscopy and histomorphometric histological analysis on 5 couples of implants. The purpose of the study is to investigate how the modified surfaces of the latest generation can guarantee a greater osseointegration both from a qualitative and quantitative level compared to the surfaces presently used and that they may represent the first example of “bioactivity”, that is, an active interaction with the processes of new bone formation and tissue healing. PMID:23285334

  7. Nano-crystalline diamond-coated titanium dental implants - a histomorphometric study in adult domestic pigs.

    PubMed

    Metzler, Philipp; von Wilmowsky, Cornelius; Stadlinger, Bernd; Zemann, Wolfgang; Schlegel, Karl Andreas; Rosiwal, Stephan; Rupprecht, Stephan

    2013-09-01

    Promising biomaterial characteristics of diamond-coatings in biomedicine have been described in the literature. However, there is a lack of knowledge about implant osseointegration of this surface modification compared to the currently used sandblasted acid-etched Ti-Al6-V4 implants. The aim of this study was to investigate the osseointegration of microwave plasma-chemical-vapour deposition (MWP-CVD) diamond-coated Ti-Al6-V4 dental implants after healing periods of 2 and 5 months. Twenty-four MWP-CVD diamond-coated and 24 un-coated dental titanium-alloy implants (Ankylos(®)) were placed in the frontal skull of eight adult domestic pigs. To evaluate the effects of the nano-structured surfaces on bone formation, a histomorphometric analysis was performed after 2 and 5 months of implant healing. Histomorphometry analysed the bone-to-implant contact (BIC). No significant difference in BIC for the diamond-coated implants in comparison to reference implants could be observed for both healing periods. Scanning electron microscopy revealed an adequate interface between the bone and the diamond surface. No delamination or particle-dissociation due to shearing forces could be detected. In this study, diamond-coated dental titanium-alloy implants and sandblasted acid-etched implants showed a comparable degree of osseointegration. PMID:23266005

  8. Computerized histomorphometric study of the splenic collagen polymorphism: A control-tissue for polarization microscopy.

    PubMed

    Alves, Antoine; Gritsch, Kerstin; Sirieix, Camille; Drevon-Gaillot, Elodie; Bayon, Yves; Clermont, Gaëlle; Boutrand, Jean-Pierre; Grosgogeat, Brigitte

    2015-10-01

    Previous articles have pointed out the presence of type III collagen within the extracellular structure of the parenchymatous organs. This study aimed to quantitatively characterize the collagen polymorphism at the capsule and parenchymal trabeculae of the largest lymphoid organ of the body i.e., the spleen, in mouse, rat, and rabbit models. Following a Picrosirius Red-Polarization procedure and computer assisted image analysis of paraffin sections, the results showed (1) a predominant and significantly higher amount of type III collagen in the trabeculae area compared to the capsule area in the three species, (2) no statistical difference among the three species concerning the parenchymal collagen polymorphism or the type I/type III collagen ratio, (3) a heterogeneous type I/type III collagen ratio varying from 0.86 (mouse) to 6.62 (rabbit) in the fibromuscular capsule region. A qualitative analysis corroborated these histomorphometric results. In conclusion, the spleen may be used as (1) a control tissue to qualitatively visualize type I and III collagen under polarization microscopy and to validate the quality of PSR staining (2) an aid to accurately calibrate the angle of polarization before quantitative measurements of type I and type III collagen. Among the studied species, the rabbit spleen appeared to be the most appropriate control tissue as it showed the highest amount of type I collagen in the capsule and a similarly high amount of type III collagen in the parenchymal trabeculae. PMID:26238067

  9. C-arm CT for histomorphometric evaluation of lumbar spine trabecular microarchitecture: a study on anorexia nervosa patients.

    PubMed

    Phan, C M; Khalilzadeh, O; Dinkel, J; Wang, I S; Bredella, M A; Misra, M; Miller, K K; Klibanski, A; Gupta, R

    2013-07-01

    Bone histomorphometry measurements require high spatial resolution that may not be feasible using multidetector CT (MDCT). This study evaluated the trabecular microarchitecture of lumbar spine using MDCT and C-arm CT in a series of young adult patients with anorexia nervosa (AN). 11 young females with AN underwent MDCT (anisotropic resolution with a slice thickness of ~626 μm) and C-arm CT (isotropic resolution of ~200 µm). Standard histomorphometric parameters the of L1 vertebral body, namely the apparent trabecular bone volume fraction (BV/TV), trabecular thickness (TbTh), trabecular number (TbN) and trabecular separation (TbSp), were analysed using MicroView software (GE Healthcare, Piscataway, NJ). Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry. Trabecular parameters derived from MDCT and C-arm CT were compared, and their association with BMD parameters was evaluated. Histomorphometric parameters derived from C-arm CT, namely TbTh, TbN and TbSp, were significantly different from the corresponding MDCT parameters. There were no significant correlations between C-arm CT-derived parameters and the corresponding MDCT-derived parameters. C-arm CT-derived parameters were significantly (p<0.001) correlated with anteroposterior L1 spine BMD and Z-scores: TbTh (r=0.723, r=0.744, respectively), TbN (r=-0.720, r=-0.712, respectively) and TbSp (r=0.656, r=0.648, respectively). BV/TV, derived from C-arm CT, was significantly associated with body mass index (r=0.636) and ideal body weight (r=0.730) (p<0.05). These associations were not present in MDCT-derived parameters. This study suggests that the spatial resolution offered by C-arm CT more accurately captures the histomorphometric parameters of trabecular morphology than MDCT in patients with AN. PMID:23640801

  10. Histomorphometric study of alveolar bone healing in rats fed a boron-deficient diet.

    PubMed

    Gorustovich, Alejandro A; Steimetz, Tammy; Nielsen, Forrest H; Guglielmotti, María B

    2008-04-01

    Bone healing after tooth extraction in rats is a suitable experimental model to study bone formation. Thus, we performed a study to determine the effects of boron (B) deficiency on bone healing by using this model. The first lower right molar of weanling Wistar rats was extracted under anesthesia. The animals were divided into two groups: +B (adequate; 3 mg B/kg diet), and -B (boron-deficient; 0.07 mg/kg diet). The animals in both groups were killed in groups of 10 at 7 and 14 days after surgery. The guidelines of the NIH for the care and use of laboratory animals were observed. The mandibles were resected, fixed, decalcified, and embedded in paraffin. Buccolingually oriented sections were obtained at the level of the mesial alveolus and used for histometric evaluations. Total alveolar volume (TAV) and trabecular bone volume per total volume (BV/TV) in the apical third of the alveolus were determined. Percentages of osteoblast surface (ObS), eroded surface (ES), and quiescent surface (QS) were determined. No statistical significant differences in food intake and body weight were observed. Histomorphometric evaluation found -B rats had 36% and 63% reductions in BV/TV at 7 and 14 days, respectively. When compared with +B rats, -B rats had significant reductions (57% and 87%) in ObS concomitantly with increases (120% and 126%) in QS at 7 and 14 days, respectively. The findings show that boron deficiency results in altered bone healing because of a marked reduction in osteogenesis. PMID:18361451

  11. A histomorphometric study of bone changes in thyroid dysfunction in rats.

    PubMed

    Allain, T J; Thomas, M R; McGregor, A M; Salisbury, J R

    1995-05-01

    Clinical studies in thyrotoxicosis reveal a state of high bone turnover leading, eventually, to osteoporosis. Recently there has been concern that thyroxine (T4) treatment may have a similar effect on bone. Rat models have been used to study the effects of T4 on bone, but the majority of studies have looked at the effects of T4 after only 3 weeks of treatment. The aim of this study was to evaluate histomorphometric changes in rats after 12 weeks of thyroxine overtreatment or 12 weeks of hypothyroidism compared with untreated control animals. Animals received either T4 200 micrograms/kg per day, 0.1% propylthiouracil, or vehicle for 12 weeks. Tetracycline was administered 1 week and 3 weeks prior to killing. Iliac crest bone was used for histomorphometry. Serum T4 measurements (taken at killing) confirmed hyper- and hypothyroidism in the appropriate animal groups (between group difference p < 0.001 by ANOVA). In hyperthyroid animals there was an increase in mineral apposition rate (MAR; 0.94 vs. 0.59 microns/day, p < 0.001) and mineral formation rate (MFR/BS; 0.24 vs. 0.12 x 10(-2) micron3/micron2 per day, p < 0.001) and a slight increase in eroded surfaces (ES/BS%; 1.54 vs. 1.36, p < 0.05) compared with controls, consistent with previous in vitro and in vivo observations. In hypothyroid rats there was a marked reduction in osteoid surfaces (OS/BS%; 1.7 vs. 24.8, p < 0.001) and MAR (0.3 vs. 0.59 micrograms/day, p < 0.001), a reduction in ES/BS% (0.51 vs. 1.36, p < 0.05), and an increase in cancellous bone volume (BV/TV%; 30.29 vs. 19.6, p < 0.05), suggesting that thyroid hormones are a requirement for normal bone turnover.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7654465

  12. Histological and histomorphometric study using an ultrasonic crestal sinus grafting procedure. A multicenter case study

    PubMed Central

    Wainwright, Marcel; Pérez-Dorao, Beatriz; Serrera-Figallo, María-Angeles; Gutierrez-Perez, José-Luis; Troedhan, Angelo; Kurrek, Andreas

    2016-01-01

    Background The aim of this study was to evaluate the efficacy of a hydrodynamic ultrasonic driven transcrestal sinus grafting procedure (Intralift ®, Acteon Company, Bordeaux, France) and the use of a bovine high temperature sintered grafting material in sinus sites with less than 5 mm remaining bone height with no additional autogenous bone in order to create a sufficient recipient site for implants. Material and Methods 12 patients (16 sinus) in this multicenter case study were included. Using a crestal approach, bone under the sinus was prepared with ultrasonic tips until the Schneiderian membrane was reached. With a trumpet shaped instrument, the Schneiderian membrane was elevated. In the new created subantral space a high temperature sintered bovine grafting material was introduced (Bego Oss, BEGO Implant Systems GmbH & Co. KG, Bremen, Germany). After 6 months biopsies were taken with a trephine bur and histologies were generated following histomorphometric analysis. Results The results showed new vital bone in average of 33.4% ± 17.05%, and 43.6% ± 16.70 of bone substitute material. No signs of abnormal inflammation were observed. Conclusions This procedure (Intralift ®) allows, using a bovine material with no additional autogenous bone, new bone formation in the sinus in order to allow place implant subantraly. Key words:Bone regeneration, sinus, intralift ®, xenogenic bone graft PMID:26946203

  13. Socket Preservation Therapy with Acellular Dermal Matrix and Mineralized Bone Allograft After Tooth Extraction in Humans: A Clinical and Histomorphometric Study.

    PubMed

    Fernandes, Patricia Garani; Muglia, Valdir Antonio; Reino, Danilo Maeda; Maia, Luciana Prado; de Moraes Grisi, Marcio Fernando; de Souza, Sergio Luís; Taba, Mario; Palioto, Daniela Bazan; de Almeida, Adriana G; Novaes, Arthur Belém

    2016-01-01

    The aim of this study was to analyze through clinical and histomorphometric parameters the use of acellular dermal matrix (ADM) with or without mineralized bone allograft (AB) on bone formation in human alveoli after a 6- to 8-month healing period. A total of 19 patients in need of extraction of the maxillary anterior teeth were selected and randomly assigned to the test group (ADM plus AB) or to the control group (ADM only). Clinical and histomorphometric measurements and histologic analysis were recorded 6 to 8 months after ridge preservation procedures. Clinical parameters and amount of mineralized and nonmineralized tissue were measured and analyzed. In the clinical measurements, the test group showed reduced bone loss in the buccopalatal dimension after 6 to 8 months (intragroup analysis P < .01). Histologic findings showed higher percentages of mineralized tissue and lower percentages of nonmineralized tissue in the test group when compared with the control group (P < .05). In this randomized controlled clinical and histomorphometric study in humans, acellular dermal matrix in association with mineralized bone allograft reduced alveolar bone loss in the anterior maxillae both in height and width after a follow-up period of 6 to 8 months. PMID:26901306

  14. Adjunctive effect of antimicrobial photodynamic therapy in induced periodontal disease. Animal study with histomorphometrical, immunohistochemical, and cytokine evaluation.

    PubMed

    de Oliveira, Paula Gabriela Faciola Pessôa; Silveira E Souza, Adriana Maria Mariano; Novaes, Arthur Belém; Taba, Mário; Messora, Michel Reis; Palioto, Daniela Bazan; Grisi, Márcio Fernando Moraes; Tedesco, Antônio Cláudio; de Souza, Sérgio Luis Scombatti

    2016-09-01

    Scaling and root planing (SRP) may not always be effective in preventing periodontal disease (PD) progression. The aim of this study was to evaluate the adjunctive effect of antimicrobial photodynamic therapy (aPDT) to SRP on induced PD in rats, analyzing histomorphometrical, immunohistochemical, and immunoenzymatic parameters. Ligatures were placed around the first mandibular molars and second maxillary molars of 60 rats to induce PD. After 14 days, they were removed and the animals were divided into six groups, with nine animals each: G1 = no treatment, G2 = SRP, G3 = light-emitting diode (LED), G4 = SRP + aPDT, G5 = aPDT, and G6 = erythrosine. The animals were euthanized after 3, 7, and 15 days. There were also two control groups (n = 3): without PD (WPD) induction and with maximum PD (PD+). In the histomorphometrical analysis of linear bone loss, G4 showed a statistically significant difference from the other experimental groups after 3 and 15 days. The tartrate-resistant acid phosphatase (TRAP)-positive cell counting was significantly lower in G4 when compared to G2 and PD+ after 3 days. Immunoenzymatic assay shows the values of the ratio (RANKL/OPG × 100). The lowest value is from the WPD group, and the group that received the SRP + aPDT treatment tended to approach this value over time. After 3 days, statistically significant differences were observed between G4 and all other experimental groups, as well as versus PD+ (one-way ANOVA + Tukey's post hoc test were performed, p < 0.05). It was concluded that the adjunctive use of aPDT in combination with SRP showed the best therapeutic results in the treatment of periodontal disease in rats. PMID:27351664

  15. A histomorphometric study of osteocytic lacunae in interradicular bone with periodontal disease.

    PubMed

    Baró, M; Ferreyra, R; Nemer, K; Rocamundi, M; Crosa, M

    2003-01-01

    Previous studies report on the differences in volume of osteocytic lacunae that are associated to different local and systemic bone pathologies. Alterations have also been reported in rats with periodontal disease. The aim of the present study was to assess the histomorphometric pattern of osteocytic lacunae of the interradicular septum in human molars with periodontal disease (PD). We took samples of the interradicular septum of 31 molars with indication of extraction of male and female patients, 18-55 years old, who attend the Department of Surgery II of the Faculty of Dentistry, National University of Cordoba and private centers. Clinical records were prepared for each patient. The corresponding radiographs were taken for all the patients. We studied 11 samples of molars with slight PD and 12 control molars free from PD. Ten samples of healthy bone corticals of vestibular or lingual tables obtained from histopathology archives were also assessed. Following extraction with atraumatic pincers, the interradicular septum was removed. The samples were fixed in buffered formaline, decalcified in EDTA and embedded in paraffin. Ten micrometer sections were stained with H&E and Masson's trichromic technique. The sections were analyzed by light microscopy. A minimum of 50 lacunae were selected at random in each sample for histomorphometric evaluation. Semi-automatic evaluation of the area and diameters of the lacunae was performed employing an image analyzer and the PRO IMAGE PLUS software. The data showed that the volume of osteocytic lacunae of interradicular bone is larger than that of the cortical bone of the vestibular or lingual tables. The latter are more ribbon-shaped and their minor diameter is smaller. No differences were found between the osteocytic lacunae of the interradicular bone of healthy molars and that of molars with slight periodontal disease. Given that the experimental data evidenced volume changes in osteocytic lacunae of severe, inflammatory

  16. Laser ablation in titanium implants followed by biomimetic hydroxyapatite coating: Histomorphometric study in rabbits.

    PubMed

    Faeda, Rafael Silveira; Spin-Neto, Rubens; Marcantonio, Elcio; Guastaldi, Antonio Carlos; Marcantonio, Elcio

    2012-07-01

    Titanium surface texture and chemistry modification successfully improves the host response and consequently the bone-to-implant contact surrounding dental implants. The aim of the present study was to investigate, using histomorphometrical-analysis, the effects of titanium surface modification by laser-ablation (Nd:YAG) followed by thin chemical deposition of HA. Forty-eight rabbits received one implant by tibiae of AS-machined (MS), laser-modified (LMS), or biomimetic hydroxyapatite-coated (HA) surface. Bone-to-implant contact (BIC) and bone area (BBT) were evaluated after 4, 8, and 12 weeks, at cortical and cancellous regions. Average BIC in the cortical region was higher (P < 0.001) on the LMS and HA implants for all periods, with no differences between LMS and HA. For the cancellous area, the LMS and HA implants showed higher (P < 0.01) BIC than MS at the initial periods. The LMS and HA showed similar values in the cortical region, but a tendency of higher values for HA in the cancellous region was observed in all periods. For the BBT, the differences were found only between HA and MS after 4 weeks in the cortical region (P < 0.05), and after 12 weeks in the cancellous area (P < 0.05). Our results showed that HA biomimetic coating preceded by laser treatment induced the contact osteogenesis and allowed the formation of a more stable bone-implant interface, even in earlier periods. PMID:22389308

  17. Maxillary Sinus Augmentation Combining Bio-Oss with the Bone Marrow Aspirate Concentrate: A Histomorphometric Study in Humans

    PubMed Central

    Pasquali, Paulo José; Teixeira, Marcelo Lucchesi; de Oliveira, Thiago Altro; de Macedo, Luis Guilherme Scavone; Aloise, Antonio Carlos; Pelegrine, André Antonio

    2015-01-01

    Purpose. To investigate the regenerative results obtained with the association of bone marrow aspirate concentrate using the Bone Marrow Aspirate Concentrate (BMAC) method to a xenogeneic bone graft (Bio-Oss) in sinus floor elevation. Materials and Methods. Using a randomized controlled study design in eight consecutive patients (age of 55.4 ± 9.2 years), 16 sinus floor lift procedures were performed with Bio-Oss alone (control group, CG, n = 8) or combined with bone marrow aspirate concentrate obtained via the BMAC method (test group, TG, n = 8). Six months after the grafting procedures, bone biopsies were harvested during implant placement and were analyzed by histomorphometry. Results. Histomorphometric analysis revealed a significantly higher amount (p < 0.05) of vital mineralized tissue in TG when compared to the CG (55.15 ± 20.91% and 27.30 ± 5.55%, resp.). For nonvital mineralized tissue, TG presented a statistically higher level of Bio-Oss resorption (p < 0.05) when compared with the CG (6.32 ± 12.03% and 22.79 ± 9.60%, resp.). Both groups (TG and CG) showed no significantly different levels (p > 0.05) of nonmineralized tissue (38.53 ± 13.08% and 49.90 ± 7.64%, resp.). Conclusion. The use of bone marrow concentrate obtained by BMAC method increased bone formation in sinus lift procedures. PMID:26543482

  18. New cementum formation induced by cyclosporin A: a histological, ultrastructural and histomorphometric study in the rat.

    PubMed

    Ayanoglou, C M; Lesty, C

    1997-08-01

    Cyclosporin A (CsA), a widely used immunosuppressive agent, is known to induce gingival overgrowth; 30 mg/kg/d of CsA were administrated orally in young and adult male Sprague-Dawley rats. The same number of rats received oil-based vehicle solution. After 4, 9, 14 and 19 wk of CsA or vehicle administration 3 control and 3 experimental rats were anaesthetized and tissues fixed by an intracardiac perfusion of fixative solution. Upper and lower jaws were dissected, demineralized and processed for Epon inclusion. Histological examination revealed the presence of large amounts of new cementum (NC) covering extensive areas of the acellular extrinsic fibre cementum (AEFC) in all the root surfaces. NC was particularly abundant at the cervical third of the roots facing the gingival connective tissue, where it occurred as layers, spurs or in both configurations. NC was characterized by its irregular outline, globular body content and infrequent presence of incremental lines. Histomorphometric evaluation by semi-automatic image analysis indicated that the volume and the external surface of NC spurs were 2.86-6.49 and 1.29-1.97-fold increased comparative to those of the AEFC covering the same root areas. Electron microscopy revealed that NC was a functional tissue with insertion of collagen fibres perpendicularly to the long axis of the root. It can be concluded that under some experimental conditions formation of abundant amounts of NC can be achieved and that these results must be taken into account for a new approach in the treatment of periodontal disease. PMID:9379322

  19. Histological and Histomorphometric Human Results of HA-Beta-TCP 30/70 Compared to Three Different Biomaterials in Maxillary Sinus Augmentation at 6 Months: A Preliminary Report

    PubMed Central

    Annibali, Susanna; Iezzi, Giovanna; Sfasciotti, Gian Luca; Cristalli, Maria Paola; Vozza, Iole; Mangano, Carlo; La Monaca, Gerardo; Polimeni, Antonella

    2015-01-01

    Objective. The aim of this investigation was to examine the bone regenerative potential of newly biphasic calcium phosphate ceramics (HA-β-TCP 30/70), by assessing histological and histomorphometric results of human specimens retrieved from sinuses augmented with HA-β-TCP 30/70, and comparing them to anorganic bovine bone (ABB), mineralized solvent-dehydrated bone allograft (MSDBA), and equine bone (EB), after a healing period of 6 months. Materials and Methods. Four consecutive patients with edentulous atrophic posterior maxilla were included in this report. A two-stage procedure was carried out for sinus augmentation with HA-β-TCP 30/70, ABB, MSDBA, and EB. After 6 months, specimens were retrieved at the time of implant placement and processed for histological and histomorphometric analyses. Results. At histological examination, all biomaterials were in close contact with the newly formed bone and showed the same pattern of bone formation; the grafted granules were surrounded by a bridge-like network of newly formed bone. A limited number of ABB particles were partially covered by connective tissue. The histomorphometric analysis revealed 30.2% newly formed bone for Ha-β-TCP 30/70, 20.1% for ABB, 16.4% for MSDBA, and 21.9% for EB. Conclusions. Within the limitations of the present investigation, these results support the successful use of HA-β-TCP 30/70 for sinus augmentation. PMID:26273589

  20. Evaluation of the Biocompatibility of Silicone Gel Implants – Histomorphometric Study

    PubMed Central

    França, Diurianne Caroline Campos; de Castro, Alvimar Lima; Soubhia, Ana Maria Pires; de Aguiar, Sandra Maria Herondina Coelho Ávila

    2013-01-01

    CONFLICT OF INTEREST: NONE DECLARED Breast implants are medical devices that are used to augment breast size or to reconstruct the breast following mastectomy or to correct a congenital abnormality. Breast implants consist of a silicone outer shell and a filler (most commonly silicone gel or saline). Approximately 5 to 10 million women worldwide have breast implants. Histomorphometric study to evaluate the biological tissue compatibility of silicone implants suitable for plastic surgery and the adverse effects and risks of this material. Thirty Wistar white rats received subcutaneous implants and the revestiment of silicone gel Silimed ®®, and randomized into six groups of five animals each, according to the type of implanted material and the time of sacrifice. Eight areas of 60.11mm2 corresponding to the obtained surgical pieces were analyzed, counting mesenchymal cells, eosinophils, and foreign body giant cells, observing an acceptable biocompatibility in all implants, for subsequent statistical analysis by Tukey test. Silicone gel showed inflammation slightly greater than for other groups, with tissue reactions varying from light to moderate, whose result was the formation of a fibrous capsule around the material, recognized by the organism as a foreign body. Despite frequent local complications and adverse outcomes, this research showed that the silicone and top layer presented an acceptable chronic inflammatory reaction, which did not significantly differ from the control group. In general, it is possible to affirm that silicone gel had acceptable levels of biocompatibility, confirmed the rare presence of foreign body giant cells, and when of the rupture, formed a fibrous capsule around the material, separating the material of the organism. PMID:24039333

  1. Quantification of Osteon Morphology Using Geometric Histomorphometrics.

    PubMed

    Dillon, Scott; Cunningham, Craig; Felts, Paul

    2016-03-01

    Many histological methods in forensic anthropology utilize combinations of traditional histomorphometric parameters which may not accurately describe the morphology of microstructural features. Here, we report the novel application of a geometric morphometric method suitable when considering structures without anatomically homologous landmarks for the quantification of complete secondary osteon size and morphology. The method is tested for its suitability in the measurement of intact secondary osteons using osteons digitized from transverse femoral diaphyseal sections prepared from two human individuals. The results of methodological testing demonstrate the efficacy of the technique when applied to intact secondary osteons. In providing accurate characterization of micromorphology within the robust mathematical framework of geometric morphometrics, this method may surpass traditional histomorphometric variables currently employed in forensic research and practice. A preliminary study of the intersectional histomorphometric variation within the femoral diaphysis is made using this geometric histomorphometric method to demonstrate its potential. PMID:26478136

  2. A histomorphometric study of the effect of doxycycline and erythromycin on bone formation in dental alveolar socket of rat

    PubMed Central

    Shahabooei, Mohammad; Razavi, Sayed Mohammad; Minaiyan, Mohsen; Birang, Reza; Behfarnia, Parichehr; Yaghini, Jaber; Naghsh, Narges; Ghalayani, Parichehr; Hajisadeghi, Samira

    2015-01-01

    Background: The aim of the present study was to evaluate whether subantimicrobial doses of doxycycline (DOX) and erythromycin (EM) used for the treatment of peri-implant osteolysis due to their anti-osteoclastogenesis can interfere with the osseous wound healing process in rat alveolar socket. Materials and Methods: Forty-five male Wistar rats had their first maxillary right molar extracted and were divided into three groups. DOX and EM at the doses of 5 mg/kg/day orally (p.o.) and 2 mg/kg/day intraperitoneally (i.p.) were administered respectively to two separate groups for 7 days after operation. In the control group the animals received normal saline (5 ml/kg). Five rats were sacrificed at 7, 14 and 21 days post-extraction in each study group. A histomorphometric analysis was used to evaluate new bone formation inside the alveolar socket. Significant level was set at 0.05. Results: The findings showed that the percentage of new bone formation (NBF) enhanced significantly on days 7 and 14. There was no significant difference in the NBF between DOX and EM groups. Conclusion: Short-term treatment with both DOX and EM enhanced new bone formation without any advances in favor of each drug. PMID:25878996

  3. Histomorphometric study on the osteocyte lacuno-canalicular network in animals of different species. I. Woven-fibered and parallel-fibered bones.

    PubMed

    Remaggi, F; Canè, V; Palumbo, C; Ferretti, M

    1998-01-01

    A comparative histomorphometric study was carried out on the extension of lacunocanalicular network in two types of bone tissue (woven and parallel-fibered) in shaft bones of various animals (Frog, Chicken, Rabbit, Bovine, Horse, Dog, Man), with the aim to understand whether the distribution of osteocyte network is related to the organization of the collagen fibers or to the animal species. By means of a light microscope (LM) connected with an image-Analyser the following parameters were measured: 1) the cross-sectional area and the volume of osteocyte lacunae; 2) the osteocyte density; 3) the number of canaliculi departing both from the whole outline of the sectional area of osteocyte lacunae and, in the parallel-fibered osteons only (both with LM and SEM), from their two opposite walls, i.e., from the wall facing the Haversian canal (vascular wall) and from that facing the cement line (peripheral wall). In all the animals studied the size and density of osteocyte lacunae as well as the extension of the canalicular network proved to be markedly higher in woven than in parallel-fibered bone, whereas no relation with the species was found. These findings suggest that the function of osteocyte is mainly involved in the regulation of skeletal homeostasis, as discussed in the present paper. PMID:9882957

  4. Effects of prenatal diclofenac sodium exposure on newborn testis: a histomorphometric study.

    PubMed

    Arslan, H; Aktaş, A; Elibol, E; Esener, Obb; Türkmen, A P; Yurt, K K; Onger, M E; Altunkaynak, B Z; Kaplan, S

    2016-05-01

    Diclofenac sodium (DS) is used primarily to treat fever and to alleviate pain and inflammation. We investigated the effects of DS exposure during gestation on the testes of rat pups to investigate the safety of its use during the prenatal period. Pregnant rats were separated into control, saline, low dose, medium dose and high dose groups. DS was given between weeks 15 and 21 of gestation. Total numbers of spermatogonia and Sertoli cells were counted in the testes of 7-day-old male rats using the physical disector method. By the end of the study, the total number of Sertoli cells was decreased significantly in a dose dependent manner in the medium and high dose groups compared to controls. No significant differences were found in the total number of spermatogonia in the control, saline and low dose DS groups. Medium and high dose DS administration reduced the total number of spermatogonia compared to other groups. We suggest that prenatal administration of DS can cause deleterious effects on the testis development, especially in high doses. PMID:26984645

  5. Dietary arginine silicate inositol complex increased bone healing: histologic and histomorphometric study

    PubMed Central

    Yaman, Ferhan; Acikan, Izzet; Dundar, Serkan; Simsek, Sercan; Gul, Mehmet; Ozercan, Ibrahim Hanifi; Komorowski, James; Sahin, Kazim

    2016-01-01

    Background Arginine silicate inositol complex (ASI; arginine 49.5%, silicon 8.2%, and inositol 25%) is a novel material that is a bioavailable source of silicon and arginine. ASI offers potential benefits for vascular and bone health. Objective The aim of this study was to evaluate the potential effects of ASI complex on bone healing of critical-sized defects in rats. Methods The rats were randomly assigned to two groups of 21 rats each. The control group was fed a standard diet for 12 weeks; after the first 8 weeks, a calvarial critical-sized defect was created, and the rats were sacrificed 7, 14, and 28 days later. The ASI group was fed a diet containing 1.81 g/kg of ASI for 12 weeks; after the first 8 weeks, a calvarial critical-sized defect was created, and the rats were sacrificed 7, 14, and 28 days later. The calvarial bones of all the rats were then harvested for evaluation. Results Osteoblasts and osteoclasts were detected at higher levels in the ASI group compared with the control group at days 7, 14, and 28 of the calvarial defect (P<0.05). New bone formation was detected at higher levels in the ASI group compared with the controls at day 28 (P<0.05). However, new bone formation was not detected at days 7 and 14 in both the groups (P>0.05). Conclusion ASI supplementation significantly improved bone tissue healing in rats with critical-sized defects. This study demonstrated that ASI can enhance bone repair and has potential as a therapeutic regimen in humans. PMID:27390517

  6. Histomorphometric Study of Alveolar Bone Healing in Rats Fed a Boron-Deficient Diet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bone healing after tooth extraction in rats is a suitable experimental model to study bone formation. Thus, we performed a study to determine the effects of boron (B) deficiency on bone healing by using this model. Weanling Wistar rats were divided into two groups: control (+B; 3 mg B/kg diet), and ...

  7. Sinus grafting with autogenous platelet-rich plasma and bovine hydroxyapatite. A histomorphometric study in minipigs.

    PubMed

    Fürst, Gabor; Gruber, Reinhard; Tangl, Stefan; Zechner, Werner; Haas, Robert; Mailath, Georg; Sanroman, Fidel; Watzek, Georg

    2003-08-01

    In this study, bovine hydroxyapatite (HA) alone or in combination with activated platelet-rich plasma (PRP) was examined for its usefulness for single-stage sinus grafting in minipigs. In 12 adult minipigs, Schneider's membrane of 24 sinuses was elevated bilaterally through an extra-oral approach. The material was divided into two groups of 12 sinuses. In one of these groups, the space between Schneider's membrane and the sinus wall was grafted with activated autogenous PRP and HA (PRP side). In the other, HA alone was used for grafting (control side). At the same time two dental implants with a machined surface were inserted into the grafting material through the facial sinus wall. Four animals of each group were sacrificed at 3, 6 and 12 weeks, and undecalcified thin-cut and ground sections (Donath 1988) stained with toluidine blue were prepared. In the facial sinus wall, fewer bone-to-implant contacts were present on the PRP side at 3 and 6 weeks than on the control side. At 12 weeks, the PRP side had caught up with the control side. In grafted bone, contacts on the PRP side were more extensive than on the control side at 3 weeks, had dropped below control side levels at 6 weeks and surpassed these at 12 weeks. This study showed that PRP has a differential effect on osseointegration in grafted bone and local host bone. Combined with HA it was not demonstrably superior to HA alone. PMID:12869013

  8. The use of platelet-rich fibrin (PRF) and PRF-mixed particulated autogenous bone graft in the treatment of bone defects: An experimental and histomorphometrical study

    PubMed Central

    Kökdere, Nesligül Niyaz; Baykul, Timuçin; Findik, Yavuz

    2015-01-01

    Background: Various materials and techniques have been developed to facilitate bone healing process and reduce its healing period. In recent studies, it is pointed out that, platelet-rich fibrin (PRF) which is derived autogenously from the own blood of the individuals, increase regeneration and accelerate the healing of the wound, due to the consisting various growing factors. The aim of the experimental study is to evaluate the efficiency of PRF and PRF/autogenous graft combination on bone healing in different time intervals. Materials and Methods: A total of 24 skeletally mature New Zealand rabbits were used. Animals were divided randomly into two groups. Two bone defects with a diameter 3, 3 mm were created on the right and left tibia in all group animals. Only particulate autogeneous bone graft, only PRF, combination of PRF and autogeneous bone graft and empty bone cavity, were performed to all animals. The animals in the first experimental group were sacrificed after 30 days. The animals in the second experimental group were sacrificed after 60 days from the operation. Histomorphometrical and statistical analysis was performed. The data were analyzed using Tukey test (P < 0.05 for osteoblast number, P < 0.01 for osteoclast and new bone area values). Results: Histomorphometrical analyzes showed that either PRF used alone or used in conjuction with autogenous bone graft, PRF accelerated the healing of the bone defects. There were statistically significant differences in osteoblast, osteoblast and new bone area values in PRF alone and autogenous graft with PRF than the other groups. Conclusion: Our preliminary result demonstrated that PRF increase new bone formation and has a positive effect on early bone healing. PMID:26604954

  9. A comparison of histomorphometric data collection methods.

    PubMed

    Stewart, Marissa C; McCormick, Lara E; Goliath, Jesse R; Sciulli, Paul W; Stout, Sam D

    2013-01-01

    Although many variables that skeletal biologists examine have been standardized, the actual techniques used to collect these data from bone thin sections vary. This project compares different methods of obtaining data (relative cortical area values) for histomorphometric research. One visual and three digital methods of histomorphometric data collection are compared: (i) Merz microscopic eyepiece counting reticule, (ii) flatbed scanner, (iii) overlaying multiple images of a thin section, and (iv) digital SLR camera with macro settings. The discussion includes a comparison of usability factors such as cost, time, user-experience, and ease-of-use, which vary for each method. Values from the different methods are compared using ANOVA tests to evaluate inter-method, inter-observer, and intra-observer variability. Intra-observer error was greater for the microscopic method, although the error values are concomitant with experience. We found no statistically significant differences between the four methods examined, but certain caveats must be addressed when these methods are used. PMID:22621277

  10. Intermittent administration of parathyroid hormone improves the repairing process of rat calvaria defects: A histomorphometric and radiodensitometric study

    PubMed Central

    Silva, Eduardo-de-Paula; Marques, Marcelo-Rocha; Dias da Silva, Marco-Antônio; Manzi, Flávio-Ricardo; Barros, Silvana-Pereira

    2015-01-01

    Background The aim of this study was to evaluate the effects of intermittent treatment of parathyroid hormone (PTH (1-34)) on the bone regeneration of critically-sized rat calvarial bone defects. Material and Methods Thirty-two male rats were trephined (4mm fullthickness diameter), in the central part of the parietal bones and divided into 2 groups of 16. The PTH group received subcutaneous injections of PTH (1-34) at 40µg/kg, 3 times a week and the control (CTL) group received the vehicle in the same regimen. The rats were sacrificed at 4 weeks post-treatment regimen, the parietal bones were extracted and samples were evaluated through histomorphometry and radiodensitometry. Results The histological observations showed that the PTH group presented more “island-like” new bone between the defect margins with fibrous tissues than did the CTL group. The PTH group significantly exhibited greater histologic bone formation than did the CTL group (1.5mm ±0.7; 1.9 mm ± 0.6, p<0.05/ for residual bone defect). The radiodensitometry analysis revealed significant differences among the PTH and CTL groups (2.1 Al eq. ±0.04; 1.8Al eq. ±0.06, p<0.05), demonstrating an increase in bone mineral density. The PTH treatment contributed to the bone formation with a higher amount of mineral and/or fibrous tissue when compared with the CTL group. Conclusions The results suggest that it was possible to increase the process of bone regeneration by accelerating the healing process in rat calvarial defects through intermittent administration of the PTH treatment. Key words: Bone, skull, rats, bone regeneration, bone density. PMID:26034928

  11. A histomorphometric study of alveolar bone modeling and remodeling in mice fed a boron-deficient diet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background and Objective: Emerging evidence indicates that boron (B) plays a role in bone formation and maintenance. Thus, a study was performed to determine whether dietary B-deficiency affects periodontal alveolar bone modeling and remodeling. Material and Methods: Weanling Swiss mice (n=30) were ...

  12. Utilization of ethyl cyanoacrylate and 2-octyl cyanoacrylate adhesives for autogenous bone graft fixation: histomorphometric study in rats.

    PubMed

    Esteves, Jônatas Caldeira; Monteiro, Jônatas Mattos; Aranega, Alessandra Marcondes; Betoni Junior, Walter; Sonoda, Celso Koogi

    2014-08-01

    The present study analyzes the repair process of autogenous bone graft in a block fixed with ethyl cyanoacrylate and 2-octyl cyanoacrylate adhesives in rat calvaria. Forty-eight rats, divided into 3 groups, received round osteotomies at the right parietal bone for the attainment of autogenous bone graft fragment, which was fixed at the opposite side to the donor site with ethyl cyanoacrylate (ethyl group) and 2-octyl cyanoacrylate (octyl group) adhesives. In the control group, bone fragment was only juxtaposed at the parietal bone surface without any fixation material. The animals were euthanized after 10 and 60 postoperative days. The calvariae were processed in a laboratory for the attainment of slides stained through the hematoxylin and eosin technique for histological and histometric analysis. The qualitative analysis showed a discrete inflammatory infiltrate in the control group and moderate inflammatory infiltrate in the ethyl and octyl groups at the 10-day period, which remained at the 60-day period, mainly in the octyl group. The bone fragment remained bonded to the recipient site through the adhesive, but graft incorporation was not observed in any of the specimens. Resorption was higher in the octyl group followed by the ethyl and control groups, both at the 10- and 60-day periods, but with no statistical significance (P < .05). Although promoting graft fixation and its maintenance at the recipient site, both studied adhesives did not allow the graft incorporation, producing a localized and discrete inflammatory reaction, which persisted at 60 days, being more intense in the octyl cyanoacrylate group. PMID:25106004

  13. The effects of 1,25-dihydroxycholecalciferol, parathyroid hormone, and thyroxine on trabecular bone remodeling in adult dogs. A histomorphometric study.

    PubMed Central

    High, W. B.; Capen, C. C.; Black, H. E.

    1981-01-01

    The effects of 1,25-dihydroxycholecalciferol (1,25-(OH)2D3), parathyroid hormone (PTH), and L-thyroxine (T4) on trabecular bone remodeling were evaluated by histomorphometric methods in adult female beagle dogs. Intravenous 1,25-(OH)2D3 (1.25 micrograms/day in equally divided doses) was administered intermittently for 6 days and withdrawn 14 days for three complete cycles. PTH was administered intravenously (2.5 U/kg/day) in divided doses 6 hours apart for 60 days. Thyroxine was given orally (1.0 mg/kg/day) in divided doses for a similar interval. Static and dynamic changes were evaluated using tetracycline and DCAF (2,4 BIS) N, N', Di (carboxymethyl) (amino methyl fluorescein) in vivo double labeling of bone from the iliac crest taken before treatment and after 60 days. The intermittent administration of 1,25-(OH)2D3 stimulated the bone resorption rate and depressed the formation rate. 1,25-(OH)2D3 increased trabecular resorption surfaces; osteoid surface, volume, and thickness; mineralization lag time; and osteoblast number but decreased the bone volume. Multiple small daily doses of PTH resulted in an overall negative balance in trabecular bone. This was associated with an increased trabecular surface-to-volume ratio, bone resorption and formation rates, active forming surfaces, osteoid volume and surface, life span of bone forming and resorbing sites, and the number of osteoclast nuclei. Thyroxine appeared to increase bone mass by enhancing the switch-over from the resorptive to the formative phase of remodeling. Coupling between osteoid apposition and mineralization was increased by recruiting more forming sites and prolonging their life span. Thyroxine increased bone resorption and formation rates, trabecular bone volume and balance, number of osteoclast nuclei, and life span of bone forming sites. The osteoid seam thickness and mineralization lag time were decreased. The present study demonstrated that 1,25-(OH)2D3, PTH, and thyroxine at the dose and

  14. Isolation and Assessment of Mesenchymal Stem Cells Derived From Bone Marrow: Histologic and Histomorphometric Study in a Canine Periodontal Defect.

    PubMed

    Paknejad, Mojgan; Eslaminejad, Mohamadreza Baghaban; Ghaedi, Baharak; Rokn, Amir-Reza; Khorsand, Afshin; Etemad-Moghadam, Shahroo; Alaeddini, Mojgan; Dehghan, Mohammad Mehdi; Moslemi, Neda; Nowzari, Hessam

    2015-06-01

    The aim of the present study was to investigate an isolation procedure to culture mesenchymal stem cells derived from bone marrow and evaluate their potential in periodontal regeneration. Potential stem cells from bone marrow, aspirated from the iliac crest of nine mongrel canines 1 to 2 years of age, were cultivated. After the examination of surface epitopes of the isolated cells, the total RNA from osteogenic, adipogenic, and chondrogenic cell cultures were analyzed by reverse transcription polymerase chain reaction (RT-PCR) to confirm stem cell gene expressions. 2 × 10(7) mL of the stem cells were loaded on 0.2 mL of anorganic bovine bone mineral (ABBM) granules. In each animal, bilateral acute/chronic intrabony periodontal defects were created surgically and by placement of ligatures around the cervical aspect of the teeth. At week 5, after flap debridement, the bilateral defects were randomly assigned to 2 treatment groups: the control group received ABBM, and the test group received BMSCs-loaded ABBM. Eight weeks after transplantation, regenerative parameters were analyzed histologically and histometrically. The RNA expressions confirmed the cultivation of mesenchymal stem cell. More new cementum and periodontal ligament (PDL) were measured in the test group (cementum: 3.33 ± 0.94 vs 2.03 ± 1.30, P = 0.027; PDL: 2.69 ± 0.73 vs 1.53 ± 1.21, P = 0.026). New bone formation was similar in both groups (2.70 ± 0.86 vs 1.99 ± 1.31; P = 0.193). Mesenchymal stem cells derived from bone marrow should be considered a promising technique for use in patients with periodontal attachment loss and merits further investigations. PMID:24383495

  15. Negative effects of nicotine on bone-resorbing cytokines and bone histomorphometric parameters in male rats.

    PubMed

    Hapidin, Hermizi; Othman, Faizah; Soelaiman, Ima-Nirwana; Shuid, Ahmad N; Luke, Douglas A; Mohamed, Norazlina

    2007-01-01

    The effects of nicotine administration on bone-resorbing cytokines, cotinine, and bone histomorphometric parameters were studied in 21 Sprague-Dawley male rats. Rats aged 3 months and weighing 250-300 g were divided into three groups. Group 1 was the baseline control (BC), which was killed without treatment. The other two groups were the control group (C) and the nicotine-treated group (N). The N group was treated with nicotine 7 mg/kg body weight and the C group was treated with normal saline only. Treatment was given by intraperitoneal injection for 6 days/week for 4 months. The rats were injected intraperitoneally with calcein 20 mg/kg body weight at day 9 and day 2 before they were killed. ELISA test kits were used to measure the serum interleukin-1 (IL-1), interleukin-6 (IL-6), and cotinine (a metabolite of nicotine) levels at the beginning of the study and upon completion of the study. Histomorphometric analysis was done on the metaphyseal region of the trabecular bone of the left femur by using an image analyzer. Biochemical analysis revealed that nicotine treatment for 4 months significantly increased the serum IL-1, IL-6, and cotinine levels as compared to pretreatment levels. In addition, the serum cotinine level was significantly higher in the N group than in the C group after 4 months treatment. Histomorphometric analysis showed that nicotine significantly decreased the trabecular bone volume (BV/TV), trabecular thickness (Tb.Th), double-labeled surface (dLS/BS), mineralizing surface (MS/BS), mineral appositional rate (MAR), and bone formation rate (BFR/BS), while causing an increase in the single-labeled surface (sLS/BS), osteoclast surface (Oc.S/BS), and eroded surface (ES/BS) as compared to the BC and C groups. In conclusion, treatment with nicotine 7 mg/kg for 4 months was detrimental to bone by causing an increase in the bone resorbing cytokines and cotinine levels. Nicotine also exerted negative effects on the dynamic trabecular histomorphometric

  16. Histomorphometric comparison after fixation with formaldehyde or glyoxal

    PubMed Central

    Wang, YN; Lee, K; Pai, S; Ledoux, WR

    2014-01-01

    Formaldehyde has long been the fixative of choice for histological examination of tissue. The use of alternatives to formaldehyde has grown, however, owing to the serious hazards associated with its use. Companies have striven to maintain the morphological characteristics of formaldehyde-fixed tissue when developing alternatives. Glyoxal-based fixatives now are among the most popular formaldehyde alternatives. Although there are many studies that compare staining quality and immunoreactivity, there have been no studies that quantify possible structural differences. Histomorphometric analysis commonly is used to evaluate diseased tissue. We compared fixation with formaldehyde and glyoxal with regard to the histomorphological properties of plantar foot tissue using a combination of stereological methods and quantitative morphology. We measured skin thickness, interdigitation index, elastic septa thickness, and adipocyte area and diameter. No significant differences were observed between formaldehyde and glyoxal fixation for any feature measured. The glyoxal-based fixative used therefore is a suitable fixative for structural evaluation of plantar soft tissue. Measurements obtained from the glyoxal-fixed tissue can be combined with data obtained from formalin-fixed for analysis. PMID:20854226

  17. Bioactive glass in cavitary bone defects: a comparative experimental study in rabbits

    PubMed Central

    Camargo, André Ferrari de França; Baptista, André Mathias; Natalino, Renato; de Camargo, Olavo Pires

    2015-01-01

    OBJECTIVES: To compare bioactive glass and autograft regarding their histomorphometric characteristics. METHODS: The authors conducted a prospective case-control experimental study on animals in order to compare the histomorphometric characteristics of bioactive glass versus autograft. Eight rabbits underwent surgery in which a cavitary defect was created in both proximal femurs. One side was filled with bioactive glass granules and the other, with autograft grafted from the contralateral side. The sides were randomized. Fourteen days after surgery, the animals were euthanized. RESULTS: Histologic analysis revealed that bone neoformation was equivalent among the two groups and the osteoblasts cell-count was higher in the femurs treated with bioactive glass. The osteocytes cell-count, however, was lower. The similarity in bone formation between both groups was consistent to literature findings. CONCLUSION: Bioactive glass is similar to autograft regarding bone neoformation in this animal model of cavitary bone defects. Level of Evidence III, Case-Control Study. PMID:26327802

  18. Histological and histomorphometric investigation of the condylar cartilage of juvenile pigs after anterior mandibular displacement.

    PubMed

    Proff, Peter; Gedrange, Tomas; Franke, Reiner; Schubert, Harald; Fanghänel, Jochen; Miehe, Bärbel; Harzer, Winfried

    2007-01-01

    The condylar cartilage of the mandible is considered a secondary growth center and represents a joint cartilage different from other cartilage structures regarding its histological structure, its histochemical and immunohistochemical properties and its growth pattern. This study aimed to histologically and histomorphometrically investigate the condylar cartilage after anterior mandibular displacement similar to functional orthopedic treatment. A total of 12 pigs (sus scrofa domesticus) aged 10 weeks were divided into an experimental group and a control group comprising 6 animals each. The experimental animals were provided bilaterally with synthetic occlusal build-ups in the posterior area which induced anterior displacement of the mandible in terminal occlusion. After 4 weeks, the temporomandibular structures were removed en bloc and the condylar cartilage was analyzed histologically and histomorphometrically. As a result, the experimental animals displayed a significantly increased total cartilage thickness of the posterocranial mandibular condyle which was primarily caused by an increase in thickness of the hypertrophic and chondogenic layers. Similarly, the proliferative layer showed a significant increase, whereas significant differences in thickness were absent in the articular layer. Increased cell proliferation was not observed in the experimental animals as compared to the controls. The changes found in the condylar cartilage area suggest that the zonal structure of the condylar cartilage may be modified by an altered spatial relationship between the mandibular condyle and the glenoid fossa. PMID:17534034

  19. Histological and histomorphometric analysis of animal experimental dehiscence defect treated with three bio absorbable GTR collagen membrane

    PubMed Central

    Behfarnia, Parichehr; Khorasani, Mitra Mohammad; Birang, Reza; Abbas, Fateme Mashhadi

    2012-01-01

    Background: Guided tissue regeneration (GTR) allows mesenchymal cells to repopulate the defects. However, there is limited information regarding the efficacy of different membranes. The present study was designed to histologically and histomorphometrically compare three collagen membranes in regenerative treatment of dehiscence defects in dogs. Materials and Methods: This 8 weeks experimental animal study comprised 4 healthy dogs. 5 × 5 mm periodontal dehiscences were created in each side of the mandible (4 dehiscences in each side of dogs’ mandible). In each side, one dehiscence defect was left uncovered as a control site and three other sites were randomly covered with different collagen membranes (Biogide (BG), Biomend (BM), and Cytoplast (CYT)). Histomorphometric and histologic analysis were conducted at 4 and 8 weeks. Data were analyzed using ANOVA, Mann-Withney, Kruskal-Wallis and Fisher 's exact tests (α = 0.05). Results: According to histomorphometric analysis there was a significant difference between treatment and control groups regarding the bone formation and the distance between the reference point and apical end of junctional epithelium (DJE) (P < 0.05). At 4 weeks, the maximum amount of bone thickness and height was observed in BG and CYT respectively, and this maximum rate was seen with the use of BG at 8 weeks. It was shown that DJE reached its highest rate in BM and CYT at 4 and 8 weeks, respectively. Organized PDL was formed in treatment groups. Conclusion: The membrane-treated groups had a statistically significant increase in bone formation and connective tissue attachment compared to control groups. However, there are some differences among experimental groups, which should be considered in GTR treatments. PMID:23559922

  20. Effect of xenograft (ABBM) particle size on vital bone formation following maxillary sinus augmentation: a multicenter, randomized, controlled, clinical histomorphometric trial.

    PubMed

    Testori, Tiziano; Wallace, Stephen S; Trisi, Paolo; Capelli, Matteo; Zuffetti, Francesco; Del Fabbro, Massimo

    2013-01-01

    The purpose of this study was a histomorphometric comparison of vital bone formation following maxillary sinus augmentation with two different particle sizes of anorganic bovine bone matrix (ABBM). Bilateral sinus floor augmentations were performed in 13 patients. Trephine bone cores were taken from the lateral window areas of 11 patients 6 to 8 months after augmentation for histologic and histomorphometric analysis. Bone samples from both the large and small particle size groups showed evidence of vital bone formation similar to that seen in previous studies, confirming the osteoconductivity of ABBM. Significant bone bridging was seen creating new trabeculae composed of the newly formed bone and residual ABBM particles. Histologic evaluation revealed the newly formed bone to be mostly woven bone with some remodeling to lamellar bone. Osteocytes were seen within the newly formed bone as well as osteoblast seams with recently formed osteoid. Isolated osteoclasts were observed on the ABBM surfaces. Vital bone formation (primary outcome measure) was more extensive in the large particle grafts compared with the small particle grafts (26.77% ± 9.63% vs 18.77% ± 4.74%, respectively). The histologic results reaffirm the osteoconductive ability of ABBM when used as the sole grafting material in maxillary sinus augmentation. The histomorphometric results at 6 to 8 months revealed a statistically significant increase (P = .02) in vital bone formation when the larger particle size was used. Additional studies should be performed to confirm these results. PMID:23820706

  1. Histomorphometric and histologic evaluation of titanium-zirconium (aTiZr) implants with anodized surfaces.

    PubMed

    Sharma, Ajay; McQuillan, A James; Shibata, Yo; Sharma, Lavanya A; Waddell, John Neil; Duncan, Warwick John

    2016-05-01

    The choice of implant surface has a significant influence on osseointegration. Modification of TiZr surface by anodization is reported to have the potential to modulate the osteoblast cell behaviour favouring more rapid bone formation. The aim of this study is to investigate the effect of anodizing the surface of TiZr discs with respect to osseointegration after four weeks implantation in sheep femurs. Titanium (Ti) and TiZr discs were anodized in an electrolyte containing DL-α-glycerophosphate and calcium acetate at 300 V. The surface characteristics were analyzed by scanning electron microscopy, electron dispersive spectroscopy, atomic force microscopy and goniometry. Forty implant discs with thickness of 1.5 and 10 mm diameter (10 of each-titanium, titanium-zirconium, anodized titanium and anodized titanium-zirconium) were placed in the femoral condyles of 10 sheep. Histomorphometric and histologic analysis were performed 4 weeks after implantation. The anodized implants displayed hydrophilic, porous, nano-to-micrometer scale roughened surfaces. Energy dispersive spectroscopy analysis revealed calcium and phosphorous incorporation into the surface of both titanium and titanium-zirconium after anodization. Histologically there was new bone apposition on all implanted discs, slightly more pronounced on anodised discs. The percentage bone-to-implant contact measurements of anodized implants were higher than machined/unmodified implants but there was no significant difference between the two groups with anodized surfaces (P > 0.05, n = 10). The present histomorphometric and histological findings confirm that surface modification of titanium-zirconium by anodization is similar to anodised titanium enhances early osseointegration compared to machined implant surfaces. PMID:26970768

  2. Polyether ether ketone implants achieve increased bone fusion when coated with nano-sized hydroxyapatite: a histomorphometric study in rabbit bone

    PubMed Central

    Johansson, Pär; Jimbo, Ryo; Naito, Yoshihito; Kjellin, Per; Currie, Fredrik; Wennerberg, Ann

    2016-01-01

    Polyether ether ketone (PEEK) possesses excellent mechanical properties similar to those of human bone and is considered the best alternative material other than titanium for orthopedic spine and trauma implants. However, the deficient osteogenic properties and the bioinertness of PEEK limit its fields of application. The aim of this study was to limit these drawbacks by coating the surface of PEEK with nano-scaled hydroxyapatite (HA) minerals. In the study, the biological response to PEEK, with and without HA coating, was investigated. Twenty-four screw-like and apically perforated implants in the rabbit femur were histologically evaluated at 3 weeks and 12 weeks after surgery. Twelve of the 24 implants were HA coated (test), and the remaining 12 served as uncoated PEEK controls. At 3 weeks and 12 weeks, the mean bone–implant contact was higher for test compared to control (P<0.05). The bone area inside the threads was comparable in the two groups, but the perforating hole showed more bone area for the HA-coated implants at both healing points (P<0.01). With these results, we conclude that nano-sized HA coating on PEEK implants significantly improved the osteogenic properties, and in a clinical situation this material composition may serve as an implant where a rapid bone fusion is essential. PMID:27103801

  3. Comparative Packaging Study

    NASA Technical Reports Server (NTRS)

    Perchonok, Michele; Antonini, David

    2008-01-01

    This viewgraph presentation describes a comparative packaging study for use on long duration space missions. The topics include: 1) Purpose; 2) Deliverables; 3) Food Sample Selection; 4) Experimental Design Matrix; 5) Permeation Rate Comparison; and 6) Packaging Material Information.

  4. [Relations between trabecular bone mass and the configuration in the space of the trabeculae of bone. Histomorphometric study of a population of 145 osteoporotic women].

    PubMed

    Chappard, D; Alexandre, C; Riffat, G

    1988-01-01

    145 women with involution osteoporosis and at least one vertebral compression noted on X-Rays, underwent a biopsy of the iliac wing and measurement of the mean cortical thickness, trabecular bony volume and parameters concerning the spatial configuration of bony trabecules (MTPT = Mean Trabecular Plate Thickness, MTPD = Mean Trabercular Plate Density, MTPS = Mean Trabecular Plate Separation), reflecting respectively the thickness, the density and the separation of the trabecules. The results were compared with those of a series of 22 control women of the same age. The post-menopausal osteoporotic patients present a decreased VTO, MTPD and MTPS with normal MTPT. Patients with senile osteoporosis show no difference as compared to the control patients of the same age. Half of the patients had a VTO higher than the spontaneous vertebral fracture threshold. Involution osteoporosis where the VTO exceeds the threshold present a significant decrease of the number of bony trabecules without decreased thickness. There is a negative correlation between age and the number of trabecules; a linear correlation between VTO and thickness, between VTO and trabecular density confirming the close relationship between mass and spatial configuration of the bone. There is a geometric configuration between density and separation of the trabecules, indicating a great sensitivity of the microstructural framework of disorganized trabecular bone. These data show that a decreased bony mass is not the only physiopathological mechanism observed during involution osteoporosis. Alterations of the spatial configuration of the trabecules or the mechanical resistance of the bony matrix are additional factors, the role of which might have been underestimated. PMID:3353672

  5. Dynamics of bone healing after osteotomy with piezosurgery or conventional drilling – histomorphometrical, immunohistochemical, and molecular analysis

    PubMed Central

    2013-01-01

    Background Piezosurgery is an osteotomy system used in medical and dental surgery. Many studies have proven clinical advantages of piezosurgery in terms of quality of cut, maneuverability, ease of use, and safety. However, few investigations have tested its superiority over the traditional osteotomy systems in terms of dynamics of bone healing. Therefore, the aim of this study was to evaluate the dynamics of bone healing after osteotomies with piezosurgery and to compare them with those associated to traditional bone drilling. Methods One hundred and ten rats were divided into two groups with 55 animals each. The animals were anesthetized and the tibiae were surgically exposed to create defects 2 mm in diameter by using piezosurgery (Piezo group) and conventional drilling (Drill group). Animals were sacrificed at 3, 7, 14, 30 and 60 days post-surgery. Bone samples were collected and processed for histological, histomorphometrical, immunohistochemical, and molecular analysis. The histological analysis was performed at all time points (n = 8) whereas the histomorphometrical analysis was performed at 7, 14, 30 and 60 days post-surgery (n = 8). The immunolabeling was performed to detect Vascular Endothelial Growth Factor (VEGF), Caspase-3 (CAS-3), Osteoprotegerin (OPG), Receptor Activator of Nuclear Factor kappa-B Ligand (RANKL), and Osteocalcin (OC) at 3, 7, and 14 days (n = 3). For the molecular analysis, animals were sacrificed at 3, 7 and 14 days, total RNA was collected, and quantification of the expression of 21 genes related to BMP signaling, Wnt signaling, inflammation, osteogenenic and apoptotic pathways was performed by qRT-PCR (n = 5). Results Histologically and histomorphometrically, bone healing was similar in both groups with the exception of a slightly higher amount of newly formed bone observed at 30 days after piezosurgery (p < 0.05). Immunohistochemical and qRT-PCR analyses didn’t detect significant differences in

  6. Low-level laser therapy affects osseointegration in titanium implants: resonance frequency, removal torque, and histomorphometric analysis in rabbits

    PubMed Central

    2016-01-01

    Objectives The purpose of this study was to investigate the effects of low-level laser therapy (LLLT) with a diode gallium-aluminum-arsenide (Ga-Al-As) low-level laser device on the healing and attachment of titanium implants in bone. Materials and Methods Thirteen New Zealand white male rabbits weighing 3.0±0.5 kg were used for this study. Dental titanium implants (3.75 mm in diameter and 8.5 mm in length, US II RBM plus fixture; Osstem, Seoul, Korea) were implanted into both femurs of each rabbit. The rabbits were randomly divided into a LLLT group and a control group. The LLLT was initiated immediately after surgery and then repeated daily for 7 consecutive days in the LLLT group. Six weeks and 12 weeks after implantation, we evaluated and compared the osseointegration of the LLLT group and control group, using histomorphometric analysis, removal torque testing, and resonance frequency analysis (RFA). The results were statistically significant when the level of probability was 0.05 or less based on a non-parametric Mann-Whitney U-test. Results The implant survival rate was about 96%. Histologically and histomorphometrically, we observed that the titanium implants were more strongly attached in LLLT group than in control group. However, there was no significant difference between the LLLT group and control group in removal torque or RFA. Conclusion Histologically, LLLT might promote cell-level osseointegration of titanium implants, but there was no statistically significant effects. PMID:26904488

  7. Operations dashboard: comparative study

    NASA Astrophysics Data System (ADS)

    Ramly, Noor Nashriq; Ismail, Ahmad Zuhairi; Aziz, Mohd Haris; Ahmad, Nurul Haszeli

    2011-10-01

    In this present days and age, there are increasing needs for companies to monitor application and infrastructure health. Apart from having proactive measures to secure their application and infrastructure, many see monitoring dashboards as crucial investment in disaster preparedness. As companies struggle to find the best solution to cater for their needs and interest for monitoring their application and infrastructure's health, this paper summarizes the studies made on several known off-the-shelf operations dashboard and in-house developed dashboard. A few criteria of good dashboard are collected from previous studies carried out by several researchers and rank them according to importance and business needs. The finalized criteria that will be discussed in later sections are data visualization, performance indicator, dashboard personalization, audit capability and alert/ notification. Comparative studies between several popular dashboards were then carried out to determine whether they met these criteria that we derived from the first exercise. The findings hopefully can be used to educate and provide an overview of selecting the best IT application and infrastructure operations dashboard that suit business needs, thus become the main contribution of this paper.

  8. Histomorphometric Evidence of Growth Plate Recovery Potential after Fractionated Radiotherapy

    PubMed Central

    Damron, Timothy A.; Horton, Jason A.; Pritchard, Meredith R.; Stringer, Matthew T.; Margulies, Bryan S.; Strauss, Judith A.; Spadaro, Joseph A.; Farnum, Cornelia E.

    2008-01-01

    This study evaluated the hypothesis that early growth plate radiorecovery is evident by growth rate, histomorphometric and immunohistochemical end points after exposure to clinically relevant fractionated radiation in vivo. Twenty-four weanling 5-week-old male Sprague-Dawley rats were randomized into eight groups. In each animal, the right distal femur and proximal tibia were exposed to five daily fractions of 3.5 Gy (17.5 Gy) with the left leg serving as a control. Rats were killed humanely at 7, 8, 9, 10, 11, 14, 15 and 16 days after the first day of radiation exposure. Quantitative end points calculated included individual zonal and overall growth plate heights, area matrix fraction, OTC-labeled growth rate, chondrocyte clone volume and numeric density, and BrdU immunohistochemical labeling for proliferative index. Transient postirradiation reductions occurred early and improved during observation for growth rate, proliferative indices, transitional/hypertrophic zone matrix area fraction, proliferative height, and clonal volume. Reserve and hypertrophic zone height remained increased during the period of observation. The current model, using a more clinically relevant fractionation scheme than used previously, shows early evidence of growth plate recovery and provides a model that can be used to correlate temporal changes in RNA and protein expression during the early period of growth plate recovery. PMID:18763859

  9. Histomorphometric evaluation of treatment of rat azoosper-mic seminiferous tubules by allotransplantation of bone marrow-derived mesenchymal stem cells

    PubMed Central

    Rahmanifar, Farhad; Tamadon, Amin; Mehrabani, Davood; Zare, Shahrokh; Abasi, Sorush; Keshavarz, Saeideh; Dianatpour, Mehdi; Khodabandeh, Zahra; Jahromi, Iman Raze ghian; Koohi-Hoseinabadi, Omid

    2016-01-01

    Objective(s): Bone marrow-derived mesenchymal stem cells (BM-MSCs) potentials make them appropriate for cell therapy including ability of differentiation and release of anti-inflammatory cytokines and growth factors secreta. For treatment of azoospermia to induce proliferation and differentiation of germ cells, MSCs transplantation has been introduced. The aim of the present experimental case-control study was to histomorphometric evaluation of the germinal cells in seminiferous tubules of azoospermic rats before and after BM-MSCs allotransplantation. Materials and Methods: In the present study, BM-MSCs were isolated from six male rats and confirmed. Their testes also served as intact negative controls. The recipient rats (n=6) were received two doses of 10 mg/kg of busulfan with 21 days interval to induce azoospermia. After cessation of spermatogenesis, the rats were allotransplanted with the BM-MSCs into efferent duct of right testes. Thirty-five days later, the right cell-treated testes were compared to left azoospermic ones. Results: Histomorphometric analyses showed that the seminiferous tubules treated with BM-MSCs had normal morphology in comparison with azoospermic testes, which were without germinal layer. In most BM-MSCs-treated seminiferous tubules, spermatogenesis was observed. Conclusion: The allotransplanted BM-MSCs could induce spermatogenesis in seminiferous tubules of azoospermic rats. PMID:27482347

  10. Histopathology and Histomorphometric Investigation of Bisphenol A and Nonylphenol on the Male Rat Reproductive System

    PubMed Central

    Kazemi, Sohrab; Feizi, Farideh; Aghapour, Fahimaeh; Joorsaraee, Gholam Ali; Moghadamnia, Ali Akbar

    2016-01-01

    Background: Bisphenol A (BPA) and nonylphenol (NP) have harmful effects on the endocrine system of humans and animals. Aim: We sought to investigate the effect of three doses of BPA and NP on the reproductive parameters of rats. Materials and Methods: Adult Wistar male rats weighing 150–200 g were used for a consecutive 35-day study. BPA and NP were given as gavage in three doses (5, 25, and 125 μg/kg). At the end of the study, the rats were anesthetized and 2 ml blood sample was obtained from the auxiliary venous plexus for the assessment of sex hormone levels. The testes were removed and kept in 10% formalin for the histomorphometric and histopathologic analyses. Results: BPA and NP significantly decreased the body weight of the animals compared to the controls (P < 0.05). The seminiferous tubule diameter and thickness of the seminiferous epithelium were significantly decreased in the groups receiving BPA and NP compared to the control (P < 0.05). The number of seminiferous tubules in every experimental group increased, except for the highest dose of NP (125 μg/kg), which showed a significant difference compared to the controls (P < 0.05). The number of spermatocytes and spermatogonia (54.97 ± 5.824, 35.78 ± 3.956, respectively) in the group receiving NP (125 μg/kg) was significantly decreased compared to the other groups. Serum levels of luteinizing hormone, Follicle stimulating hormone, and testosterone did not show any significant change compared to the controls. Conclusion: Based on the results, all three doses of BPA and NP significantly produced weight loss, as well as destruction of the testis tissue and impairment of the spermatogenesis. PMID:27298816

  11. Comparative Packaging Study

    NASA Technical Reports Server (NTRS)

    Perchonok, Michele H.; Oziomek, Thomas V.

    2009-01-01

    Future long duration manned space flights beyond low earth orbit will require the food system to remain safe, acceptable and nutritious. Development of high barrier food packaging will enable this requirement by preventing the ingress and egress of gases and moisture. New high barrier food packaging materials have been identified through a trade study. Practical application of this packaging material within a shelf life test will allow for better determination of whether this material will allow the food system to meet given requirements after the package has undergone processing. The reason to conduct shelf life testing, using a variety of packaging materials, stems from the need to preserve food used for mission durations of several years. Chemical reactions that take place during longer durations may decrease food quality to a point where crew physical or psychological well-being is compromised. This can result in a reduction or loss of mission success. The rate of chemical reactions, including oxidative rancidity and staling, can be controlled by limiting the reactants, reducing the amount of energy available to drive the reaction, and minimizing the amount of water available. Water not only acts as a media for microbial growth, but also as a reactant and means by which two reactants may come into contact with each other. The objective of this study is to evaluate three packaging materials for potential use in long duration space exploration missions.

  12. Evaluation of an experimental rat model for comparative studies of bleaching agents

    PubMed Central

    Cintra, Luciano Tavares Angelo; Benetti, Francine; Ferreira, Luciana Lousada; Rahal, Vanessa; Ervolino, Edilson; Jacinto, Rogério de Castilho; Gomes, João Eduardo; Briso, André Luiz Fraga

    2016-01-01

    ABSTRACT Dental materials, in general, are tested in different animal models prior to their clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats’ vital teeth. Material and methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals (control) were untreated. The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated by histomorphometric analysis with inflammatory cell counting in the coronal and radicular thirds of the pulp. The counting of fibroblasts was also performed. Scores were attributed to the odontoblastic layer and to vascular changes. The tertiary dentin area and the pulp chamber central area were histomorphometrically measured. Data were compared by the analysis of variance and the Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the occlusal third of the coronal pulp until the time of 15 min for both concentrations of bleaching gels. In 30 and 45 min groups of each concentration, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, a reduction in the pulp chamber central area and an enlargement of tertiary dentin area were observed without the detection of inflammation areas. Conclusion The rat model of extra coronal bleaching showed to be adequate for bleaching protocols studies, as it was possible to observe alterations in the pulp tissues and in the tooth structure caused by different concentrations and periods of application of bleaching agents. PMID:27008262

  13. Evaluation of an experimental rat model for comparative studies of bleaching agents

    PubMed Central

    CINTRA, Luciano Tavares Angelo; BENETTI, Francine; FERREIRA, Luciana Louzada; RAHAL, Vanessa; ERVOLINO, Edilson; JACINTO, Rogério de Castilho; GOMES, João Eduardo; BRISO, André Luiz Fraga

    2016-01-01

    ABSTRACT Dental materials in general are tested in different animal models prior to the clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents, by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats’ vital teeth. Material and Methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals were untreated (control). The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated through histomorphometric analysis with inflammatory cell count in the coronal and radicular thirds of the pulp. Fibroblasts were also counted. Scores were attributed to odontoblastic layer and vascular changes. Tertiary dentin area and pulp chamber central area were measured histomorphometrically. Data were compared by analysis of variance and Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the coronal pulp occlusal third up to the 15-min application groups of each bleaching gel. In the groups exposed to each concentration for 30 and 45 min, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, reduction on the pulp chamber central area and enlargement of the tertiary dentin area were observed, without the detection of inflammation areas. Conclusion The rat model of extracoronal bleaching showed to be adequate for studies of bleaching protocols, as it was possible to observe alterations in the pulp tissues and tooth structure caused by different concentrations and application periods of bleaching agents. PMID:27119766

  14. Comparison of histomorphometrical data obtained with two different image analysis methods.

    PubMed

    Ballerini, Lucia; Franke-Stenport, Victoria; Borgefors, Gunilla; Johansson, Carina B

    2007-08-01

    A common way to determine tissue acceptance of biomaterials is to perform histomorphometrical analysis on histologically stained sections from retrieved samples with surrounding tissue, using various methods. The "time and money consuming" methods and techniques used are often "in house standards". We address light microscopic investigations of bone tissue reactions on un-decalcified cut and ground sections of threaded implants. In order to screen sections and generate results faster, the aim of this pilot project was to compare results generated with the in-house standard visual image analysis tool (i.e., quantifications and judgements done by the naked eye) with a custom made automatic image analysis program. The histomorphometrical bone area measurements revealed no significant differences between the methods but the results of the bony contacts varied significantly. The raw results were in relative agreement, i.e., the values from the two methods were proportional to each other: low bony contact values in the visual method corresponded to low values with the automatic method. With similar resolution images and further improvements of the automatic method this difference should become insignificant. A great advantage using the new automatic image analysis method is that it is time saving--analysis time can be significantly reduced. PMID:17387585

  15. EFFECT OF GLABRIDIN AND GLYCYRRHIZIC ACID ON HISTOMORPHOMETRIC PARAMETERS OF BONES IN OVARIECTOMIZED RATS.

    PubMed

    Klasik-Ciszewska, Sylwia; Kaczmarczyk-Sedlak, Ilona; Wojnar, Weronika

    2016-01-01

    Licorice is a medicinal plant showing many therapeutic activities. Its roots contain numerous pharmacologically active compounds such as a triterpenoid saponin--glycyrrhizic acid and an isoflavan--glabridin. There are reports indicating that glabridin exhibits estrogen-like activity, therefore it can be classified into phytoestrogens, which may soothe menopause symptoms including postmenopausal osteoporosis. Due to this fact, the aim of the presented study was to evaluate the effect of glabridin and glycyrrhizic acid on histomorphometric parameters of bones in rats with ovariectomy-induced osteoporosis. The animals were divided into 6 group: (C)--control rats, (OVX)--ovariectomized rats, (OVX + E)--ovariectomized rats receiving estradiol at a dose of 0.1 mg/kg p.o., (OVX + G)--ovariectomized rats receiving genistein at a dose of 5 mg/kg p.o., (OVX + GL --ovariectomized rats treated with glabridin at a dose of 5 mg/kg p.o. and (OVX + GA)--ovariectomized rat administered with glycyrrhizic acid at a dose of 15 mg/kg p.o. Estradiol and genistein served as the positive controls in the study. Several macrometric and histomorphometric parameters were analyzed in the bones of tested rats. Obtained results indicate that glabridin shows slightly positive effect on osteoporotically changed bone tissue, and glycyrrhizic acid reveals meager influence on skeletal system with no preventive significance. PMID:27180445

  16. Histologic and histomorphometric changes of testis following oral exposure to methyl tertiary-butyl ether in adult rat.

    PubMed

    Gholami, S; Ansari-Lari, M; Khalili, L

    2015-01-01

    Methyl tertiary-butyl ether (MTBE) is used to reduce carbon monoxide and ozone in urban air and to boost fuel octane. There is a lack of knowledge in the literature about the histomorphometric changes of the testis following exposure to MTBE. Therefore, this experimental study was performed to determine the effect of oral exposure to MTBE on histologic and histomorphometric changes of testis in adult rat. A total of 25 adult male Sprague-Dawley rats were randomly divided into five equal experimental groups: control, almond oil and three treatment groups which received 400, 800 and 1600 mg/kg/day MTBE in almond oil by gavages for 30 consecutive days. Histomorphometric analysis showed no significant difference in absolute and relative testis weight, connective tissue thickness, germinal epithelium height, tunica albuginea thickness and Sertoli cell numbers between experimental groups (P>0.05). However, trend analysis showed that the seminiferous tubule diameter increased and interstitial cell numbers as well as spermatocyte and spermatid cell numbers decreased significantly in MTBE treated groups (P<0.05). It may be concluded that MTBE could exert adverse effects on spermatogenic cells in adult rat. Whether the observed changes in the present study are due to the direct effect of MTBE via passing blood-testis barrier or its indirect effect through another mechanism should be elucidated in future studies. PMID:27175191

  17. The Effects of Pyridaben Pesticide on the Histomorphometric, Hormonal Alternations and Reproductive Functions of BALB/c Mice

    PubMed Central

    Ebadi Manas, Ghodrat; Hasanzadeh, Shapour; Parivar, Kazem

    2013-01-01

    Objective(s): The adverse effects of pyridaben on reproductive system in male animals are not well established. This study was designed to elucidate how pyridaben can effects the histomorphometric, hormonal alternations and reproductive functions of BALB/c mice. Materials and Methods: For this study, 80 adult and apparently healthy male BALB/c mice were divided into three groups Viz, control, test group 1 and test group 2. Test groups 1 and 2 were received the toxin at doses of 53 mg/kg. BW, and 212 mg/kg. BW, respectively. The experiment period for both groups was 10, 25 and 45 days. Results: The levels of FSH, LH and testosterone were significantly (P<0.05) decreased on the dose and time dependant means. The levels of the ROS and NOS were significantly (P<0.05) increased in all test groups. The percent body weight gains significantly (P<0.05) reduced, whereas weights significantly (P<0.05) increased in test groups in a dose and time dependant manner. The histomorphometric and stereologic findings, including diameters of somniferous tubules, thickness of somniferous tubules epithelium, the leydig's cell distribution, TDI, SI, RI revealed that, all these parameters are also significantly (P<0.05) reduces in test groups in a dose and time dependant manner. Conclusion: Pyridaben causes histomorphometric and stereologic changes in testis, as well as hormonal and reproductive functional alternations in BALB/c mice. PMID:24379962

  18. Effect of Porous Titanium Granules on Bone Regeneration and Primary Stability in Maxillary Sinus: A Human Clinical, Histomorphometric, and Microcomputed Tomography Analyses.

    PubMed

    Dursun, Ceyda Kanli; Dursun, Erhan; Eratalay, Kenan; Orhan, Kaan; Tatar, Ilkan; Baris, Emre; Tözüm, Tolga Fikret

    2016-03-01

    The aim of this randomized controlled study was to comparatively analyze the new bone (NB), residual bone, and graft-bone association in bone biopsies retrieved from augmented maxillary sinus sites by histomorphometry and microcomputed tomography (MicroCT) in a split-mouth model to test the efficacy of porous titanium granules (PTG) in maxillary sinus augmentation. Fifteen patients were included in the study and each patient was treated with bilateral sinus augmentation procedure using xenograft (equine origine, granule size 1000-2000 μm) and xenograft (1 g) + PTG (granule size 700-1000 μm, pore size >50 μm) (1 g), respectively. After a mean of 8.4 months, 30 bone biopsies were retrieved from the implant sites for three-dimensional MicroCT and two-dimensional histomorphometric analyses. Bone volume and vital NB percentages were calculated. Immediate after core biopsy, implants having standard dimensions were placed and implant stability quotient values were recorded at baseline and 3 months follow-up. There were no significant differences between groups according to residual bone height, residual bone width, implant dimensions, and implant stability quotient values (baseline and 3 months). According to MicroCT and two-dimensional histomorphometric analyses, the volume of newly formed bone was 57.05% and 52.67%, and 56.5% and 55.08% for xenograft + PTG and xenograft groups, respectively. No statistically significant differences found between groups according to NB percentages and higher Hounsfield unit values were found for xenograft + PTG group. The findings of the current study supports that PTG, which is a porous, permanent nonresorbable bone substitute, may have a beneficial osteoconductive effect on mechanical strength of NB in augmented maxillary sinus. PMID:26872278

  19. Histomorphometric analysis of rat skeleton following spaceflight

    NASA Technical Reports Server (NTRS)

    Wronski, T. J.; Morey-Holton, E. R.; Doty, S. B.; Maese, A. C.; Walsh, C. C.

    1987-01-01

    Male Sprague-Dawley rats were placed in orbit for 7 days aboard the space shuttle. Bone histomorphometry was performed in the long bones and lumbar vertebrae of flight rats and compared with data derived from ground-based control rats. Trabecular bone mass was not altered during the 1st wk of weightlessness. Strong trends were observed in flight rats for decreased periosteal bone formation in the tibial diaphysis, reduced osteoblast size in the proximal tibia, and decreased osteoblast surface and number in the lumbar vertebra. For the most part, histological indexes of bone resorption were normal in flight rats. The results indicate that 7 days of weightlessness are not of sufficient duration to induce histologically detectable loss of trabecular bone in rats. However, cortical and trabecular bone formation appear to be diminished during the 1st wk of spaceflight.

  20. Effect of different storage media on the regenerative potential of autogenous bone grafts: a histomorphometrical analysis in rabbits.

    PubMed

    Rocha, Flaviana Soares; Batista, Jonas Dantas; Zanetta-Barbosa, Darceny; Dechichi, Paula

    2013-12-01

    The success of autogenous bone graft is related to the graft cell viability. In bone-grafting procedures, harvested grafts are often maintained in extraoral media while the recipient site is prepared. The aim of this study was to evaluate in vivo the effect of storage media over autogenous bone grafts during the transsurgical time. Two grafts were removed bilaterally from the calvaria of 18 rabbits. One graft was immediately fixed in the mandibular angle (control group), and the other was maintained in air exposure (dry group), 0.9% NaCl solution (saline group), or platelet-poor plasma (PPP group) during 30 minutes and stabilized in the symmetrical location of control grafts. After 28 days, the animals were euthanized and the bone fragments were removed, demineralized, and embedded in paraffin. Histological evaluation was performed under light microscope. Empty lacunae and bone graft area quantification were carried out for the sections. The histomorphometrical analysis revealed reduction of the graft area and increase of empty lacunae in the dry group when compared with control. No significant differences were found in the number of empty lacunae or bone graft area between the saline group and its control and also between the PPP group and its control. The dry group showed more empty lacunae and less graft area than the saline and PPP groups. In accordance with the results, PPP and physiologic solution demonstrated osteocyte preservation and bone graft area maintenance, being satisfactory storage media for autogenous bone grafts during the transsurgical period. PMID:21905882

  1. Effects of Immediate Orthodontic and Orthopedic Forces on Peri-Miniscrew Bones: Histomorphologic and Histomorphometric Assessment in Dogs

    PubMed Central

    Rismanchian, Mansour; Raji, Sayed Hamid; Teimori Rik, Danesh; Mohammad Razavi, Sayed; Khalighinejad, Navid; Goroohi, Hossein; Badrian, Hamid

    2012-01-01

    Aim. The aim of this study was histomorphologic and histomorphometric evaluation of peri-screw bone after immediate orthodontic and orthopedic forces and comparing them with a control group. Materials and Methods. 18 dual-top miniscrews were inserted in the premolar region of three Iranian dogs. Screws were divided into three groups: (1) the first group undergoing immediate orthodontic force of 300 cN, (2) the second group undergoing immediate orthopedic force of 600 cN and (3) a control group. Screws were explanted with adequate amount of surrounding bone after three months. Bone-screw contact (BSC), percentage of lamellar bone, and percentage of woven bone were evaluated. Wilcoxon and Man Whitney tests were used to analyze the data using SPSS software ver. 15 (α = 0.05). Results. There was no significant difference among the groups in terms of bone-screw contact (P  value = 0.42), percentage of lamellar bone (P  value = 0.83), and percentage of woven bone (P  value = 0.88). Conclusion. By applying orthodontic and orthopedic forces to mini-screws the quality of surrounding bone and osseointegration will not be affected. Clinical Significance. Application of force to mini-screws is helpful in orthodontic-screw therapies. PMID:23319949

  2. Histomorphometric Evaluation of Anorganic Bovine Bone Coverage to Reduce Autogenous Grafts Resorption: Preliminary Results

    PubMed Central

    Maiorana, Carlo; Beretta, Mario; Battista Grossi, Giovanni; Santoro, Franco; Scott Herford, Alan; Nagursky, Heiner; Cicciù, Marco

    2011-01-01

    Physiologic resorption due to remodeling processes affects autogenous corticocancellous grafts in the treatment of atrophic jawbone alveolar ridges. Such a situation in the past made overgrafting of the recipient site mandatory to get enough bone support to dental implants in order to perform a prosthetic rehabilitation. Anorganic bovine bone, conventionally used to treat alveolar bone deficiencies in implant surgery, showed a high osteoconductive property thanks to its micro and macrostructure very similar to that of human hydroxyapatite. An original technique provides for the application of a thin layer of anorganic bovine bone granules and a collagen membrane on the top of the corticocancellous onlay bone grafts to reduce in a remarkable way the graft resorption due to remodeling. The results of a clinical prospective study and a histomorphometric analysis done on autogenous grafts harvested from the iliac crest showed that the proposed technique is able to maintain the original bone volume of the corticocancellous blocks. PMID:21566694

  3. Titanium implants with two different surfaces: Histomorphologic and histomorphometric evaluation in rabbit tibia.

    PubMed

    Biasotto, M; Sandrucci, M A; Antoniolli, F; Stebel, M; Grill, V; Di Lenarda, R; Dorigo, E

    2005-01-01

    This study aimed to compare two different implant surface treatments of the implant system Bi-Implant (Plan 1 Health): one surface sandblasted with hydroxyapatite (HA) (Osseogrip(R)) and one machined surface. Histomorphologic and histomorphometric evaluations of the bone healing at the interface between a titanium implant and bone were performed using a light microscopic technique. Twenty-four commercially pure titanium implants with a smooth surface and 24 implants with a sandblasted surface were inserted in the tibias of 12 rabbits. The 12 rabbits were divided into three groups, each consisting of four animals, were sacrificed at 4 weeks (I group), 8 weeks (II group) and 12 weeks (III group) after the insertion of the bio-material. The results emphasized that in the sections examined with the light microscope, the bone was in intimate contact with the implant surface and the bone surrounding the implants was mostly lamellar. After 4 weeks, mature bone tightly surround-ing some areas of the implant perimeter was observed. The implant with the Osseogrip(R) surface showed an average percentage of bone-implant contact (%BIC) equal to 33%, while the one with the machined surface showed a %BIC equal to 17%. After 8 weeks, a progressive increase in mineralized bone surrounding the implant surface was detected, making the results of the machined surface superposable to the Osseogrip(R) surface results (48 and 44%). After 12 weeks, the implants with the machined surface exhibited close contact with the bone tissue corresponding to 62% of their perimeter, while for the implants with the Os-seogrip(R) surface the surface contact was 67% of the implant surface. The morphometric evaluation of %BIC at the three time points evidenced an increase in bone-titanium contact over time on both machined and Osseogrip(R) surfaces. Moreover, implants with rough surfaces demonstrated better behavior than the implants with the machined surface when taking into account the earlier

  4. Histomorphometric and biomechanical analyses of osseointegration of four different orthodontic mini implant surfaces

    NASA Astrophysics Data System (ADS)

    Yadav, Sumit

    Objective: To evaluate the osseointegration potential of four different surfaces of mini-implants. We hypothesized that mini-implants surface roughness alters the intrinsic biomechanical properties of the bone integrated to titanium. Materials and Methods: Mini implants and circular discs were made from alloy Ti6Al4V grade 5. On the basis of surface treatment study was divided into 4 groups: Group 1: Machined: no surface treatment, Group 2: Acid etched: with hydrochloric acid, Group 3: Grit Blasted with alumina and Group 4: Grit blasted +Acid etched. Surface roughness parameters (mean surface roughness: Ra and Quadratic Average roughness: Rq) of the four discs from each group were measured by the optical profilometer. Contact angle measurement of 3 discs from each group was done with a Goniometer. Contact angle of liquids with different hydrophobicity and hydrophilicity were measured. 128 mini implants, differing in surface treatment, were placed into the tibias and femurs of 8 adult male New Zealand white rabbits. Biomechanical properties (Removal torque and hardness) measurements and histomorphometric observations were measured. Results: Ra and Rq of groups were: Machined (1.17+/-0.11, 2.59+/-0.09) Acid etched (1.82+/-0.04, 3.17+/-0.13), Grit blasted (4.83+/-0.23, 7.04+/-0.08), Grit blasted + Acid etched (3.64+/-0.03, 4.95+/-0.04) respectively. Group 4 had significantly (p=0.000) lower Ra and Rq than Group 3. The interaction between the groups and liquid was significant. Group 4 had significantly lower contact angle measurements (40.4°, 26.9°), both for blood and NaCl when compared to other three groups (p≤0.01). Group 4 had significantly higher torque than Group 3 (Tibia: 13.67>9.07N-cm; Femur: 18.21>14.12N-cm), Group 4 (Tibia: 13.67>9.78N-cm; Femur: 18.21>12.87N-cm), and machined (Tibia: 13.67>4.08N-cm; Femur: 18.21>6.49N-cm). SEM analysis reveals significantly more bone implant gap in machined implant surfaces than treated implant surfaces. Bone to implant

  5. Histomorphometric Assessment of Cancellous and Cortical Bone Material Distribution in the Proximal Humerus of Normal and Osteoporotic Individuals

    PubMed Central

    Sprecher, Christoph M.; Schmidutz, Florian; Helfen, Tobias; Richards, R. Geoff; Blauth, Michael; Milz, Stefan

    2015-01-01

    Abstract Osteoporosis is a systemic disorder predominantly affecting postmenopausal women but also men at an advanced age. Both genders may suffer from low-energy fractures of, for example, the proximal humerus when reduction of the bone stock or/and quality has occurred. The aim of the current study was to compare the amount of bone in typical fracture zones of the proximal humerus in osteoporotic and non-osteoporotic individuals. The amount of bone in the proximal humerus was determined histomorphometrically in frontal plane sections. The donor bones were allocated to normal and osteoporotic groups using the T-score from distal radius DXA measurements of the same extremities. The T-score evaluation was done according to WHO criteria. Regional thickness of the subchondral plate and the metaphyseal cortical bone were measured using interactive image analysis. At all measured locations the amount of cancellous bone was significantly lower in individuals from the osteoporotic group compared to the non-osteoporotic one. The osteoporotic group showed more significant differences between regions of the same bone than the non-osteoporotic group. In both groups the subchondral cancellous bone and the subchondral plate were least affected by bone loss. In contrast, the medial metaphyseal region in the osteoporotic group exhibited higher bone loss in comparison to the lateral side. This observation may explain prevailing fracture patterns, which frequently involve compression fractures and certainly has an influence on the stability of implants placed in this medial region. It should be considered when planning the anchoring of osteosynthesis materials in osteoporotic patients with fractures of the proximal humerus. PMID:26705200

  6. Sex work: a comparative study.

    PubMed

    McCarthy, Bill; Benoit, Cecilia; Jansson, Mikael

    2014-10-01

    Explanations of adult involvement in sex work typically adopt one of two approaches. One perspective highlights a variety of negative experiences in childhood and adolescence, including physical and sexual abuse, family instability, poverty, associations with "pimps" and other exploiters, homelessness, and drug use. An alternative account recognizes that some of these factors may be involved, but underscores the contribution of more immediate circumstances, such as current economic needs, human capital, and employment opportunities. Prior research offers a limited assessment of these contrasting claims: most studies have focused exclusively on people working in the sex industry and they have not assessed the independent effects of life course variables central to these two perspectives. We add to this literature with an analysis that drew on insights from life course and life-span development theories and considered the contributions of factors from childhood, adolescence, and adulthood. Our comparative approach examined predictors of employment in sex work relative to two other low-income service or care work occupations: food and beverage serving and barbering and hairstyling. Using data from a study of almost 600 workers from two cities, one in Canada and the other in the United States, we found that both immediate circumstances and negative experiences from early life are related to current sex work involvement: childhood poverty, abuse, and family instability were independently associated with adult sex work, as were limited education and employment experience, adult drug use, and marital status. PMID:24671729

  7. Bone marrow stem cells assuage radiation-induced damage in a murine model of distraction osteogenesis: A histomorphometric evaluation.

    PubMed

    Zheutlin, Alexander R; Deshpande, Sagar S; Nelson, Noah S; Kang, Stephen Y; Gallagher, Kathleen K; Polyatskaya, Yekaterina; Rodriguez, Jose J; Donneys, Alexis; Ranganathan, Kavitha; Buchman, Steven R

    2016-05-01

    The purpose of this study is to determine if intraoperatively placed bone marrow stem cells (BMSCs) will permit successful osteocyte and mature bone regeneration in an isogenic murine model of distraction osteogenesis (DO) following radiation therapy (XRT). Lewis rats were split into three groups, DO only (Control), XRT followed by DO (xDO) and XRT followed by DO with intraoperatively placed BMSCs (xDO-BMSC). Coronal sections from the distraction site were obtained, stained and analyzed via statistical analysis with analysis of variance (ANOVA) and subsequent Tukey or Games-Howell post-hoc tests. Comparison of the xDO-BMSC and xDO groups demonstrated significantly improved osteocyte count (87.15 ± 10.19 vs. 67.88 ± 15.38, P = 0.00), and empty lacunae number (2.18 ± 0.79 vs 12.34 ± 6.61, P = 0.00). Quantitative analysis revealed a significant decrease in immature osteoid volume relative to total volume (P = 0.00) and improved the ratio of mature woven bone to immature osteoid (P = 0.02) in the xDO-BMSC compared with the xDO group. No significant differences were found between the Control and xDO-BMSC groups. In an isogenic murine model of DO, BMSC therapy assuaged XRT-induced cellular depletion, resulting in a significant improvement in histological and histomorphometric outcomes. PMID:27059203

  8. Clinical, Histological, and Histomorphometric Evaluation of Demineralized Freeze-Dried Cortical Block Allografts for Alveolar Ridge Augmentation.

    PubMed

    Aslan, Elcin; Gultekin, Alper; Karabuda, Cuneyt; Mortellaro, Carmen; Olgac, Vakur; Mijiritsky, Eitan

    2016-07-01

    Autogenous bone-block grafts are the "gold standard" for block bone grafting, but have several disadvantages. Allografts have the potential to overcome these disadvantages. The purpose of this study was to evaluate the clinical and histomorphometric features of demineralized freeze-dried cortical block allografts (DCBA) used for ridge augmentation. Eleven patients who showed bone deficiencies of <5 mm in the horizontal plane were included in this study. The recipient sites were reconstructed with DCBA. The primary outcomes of interest were bone-width measurements, postoperative clinical evaluations, and histomorphometric analysis of the biopsy samples collected during the implant surgery. Clinical analysis showed that the mean gain in horizontal bone was 1.65 ± 0.14 mm, and that the mean percentage of graft resorption was 5.39 ± 2.18%. On postoperative day 7, edema, pain, and bruising were observed in 18.2%, 0%, and 9.1% of the patients, respectively. In the biopsy samples, the mean percentages of newly formed bone, residual block allograft, and marrow and connective tissue were 40.30 ± 24.59%, 40.39 ± 21.36%, and 19.30 ± 15.07%, respectively. All of the block grafts were successfully integrated into the recipient sites. DCBA may be a viable alternative for treating both deficient maxillary and mandibular alveolar ridges. PMID:27380561

  9. Comparative study of membranes induced by PMMA or silicone in rats, and influence of external radiotherapy.

    PubMed

    de Monès, Erwan; Schlaubitz, Silke; Oliveira, Hugo; d'Elbée, Jean-Marie; Bareille, Reine; Bourget, Chantal; Couraud, Lionel; Fricain, Jean-Christophe

    2015-06-01

    The induced membrane technique has been used for long bone defect reconstruction after traumatism. One of the major drawbacks of this method is the difficult removal of the polymethyl methacrylate spacer after membrane formation. We therefore replaced the stiff PMMA spacer with a semi-flexible medical grade silicone spacer. This study aimed to compare subcutaneously formed membranes, induced by PMMA and silicone, in the irradiated or not irradiated areas within 28 rats that received the spacers. Histological analysis was performed to evaluate the composition of the membrane and to quantify the amount of vessels. Histomorphometric measurements were used to evaluate membranes' thickness, while fibrosis and inflammation were scored. The expression of VEGF and BMP-2 in lysates of the crushed membranes was determined by Western blotting. ALP expression was analyzed in HBMSC cultures in contact with the same lysates. Non-irradiated membranes induced by the two spacer types were non-inflammatory, fibrous and organized in layers. Irradiation did not change the macroscopic properties of membranes that were induced by silicone, while PMMA induced membranes were sensitive to the radiotherapy, resulting in thicker, strongly inflammatory membranes. Irradiated membranes showed an overall reduced osteogenic potential. Medical grade silicone is safe for the use in radiotherapy and might therefore be of great advantage for patients in need of cancer treatment. PMID:25770925

  10. The efficacy of the use of IR laser phototherapy associated to biphasic ceramic graft and guided bone regeneration on surgical fractures treated with miniplates: a histological and histomorphometric study on rabbits.

    PubMed

    Pinheiro, Antonio L B; Aciole, Gilberth Tadeu Santos; Ramos, Thais Andrade; Gonzalez, Tayná Assunção; da Silva, Laís Nogueira; Soares, Luiz G Pinheiro; Aciole, Jouber Mateus Santos; dos Santos, Jean Nunes

    2014-01-01

    The aim of the present study was to assess, by light microscopy and histomorphometry, the repair of surgical fractures fixed with internal rigid fixation (IRF) treated or not with IR laser (λ780 nm, 50 mW, 4 × 4 J/cm(2) = 16 J/cm(2), ϕ = 0.5 cm(2), CW) associated or not to the use of hydroxyapatite and guided bone regeneration. Surgical tibial fractures were created under general anesthesia on 15 rabbits that were divided into 5 groups, maintained on individual cages, at day/night cycle, fed with solid laboratory pelted diet, and had water ad libidum. The fractures in groups II, III, IV, and V were fixed with miniplates. Animals in groups III and V were grafted with hydroxyapatite and GBR technique used. Animals in groups IV and V were irradiated at every other day during two weeks (4 × 4 J/cm(2), 16 J/cm(2) = 112 J/cm(2)). Observation time was that of 30 days. After animal death, specimens were taken, routinely processed to wax, cut and stained with HA and Sirius red, and used for histological assessment. The results of both analyses showed a better bone repair on all irradiated subjects especially when the biomaterial and GBR were used. In conclusion, the results of the present investigation are important clinically as they are suggestive that the association of hydroxyapatite, and laser light resulted in a positive and significant repair of complete tibial fractures treated with miniplates. PMID:23649614

  11. Comparative Studies of Acculturative Stress.

    ERIC Educational Resources Information Center

    Berry, J. W.; And Others

    1987-01-01

    Studies of acculturative stress are reported from Canada. The reduction in health status among people undergoing acculturation has psychological, somatic, and social aspects. The stress varies across types of groups and individual differences. Further study is needed to determine variations across host societies. (VM)

  12. Comparative Studies in Special Education.

    ERIC Educational Resources Information Center

    Mazurek, Kas, Ed.; Winzer, Margret A., Ed.

    This text presents 26 case studies which examine special education provisions for children in the world today. The reports focus on the current state of special education in selected nations and major issues and controversies in the field of special education within those nations. Each case study addresses the following themes: (1) prevalence of…

  13. Variation in osteon histomorphometrics and their impact on age-at-death estimation in older individuals.

    PubMed

    Goliath, Jesse R; Stewart, Marissa C; Stout, Sam D

    2016-05-01

    Histomorphometric studies have reported relations between osteon size and age; however, data focused on the shape of osteons is sparse. The purpose of this study was to determine how osteon circularity (On.Cr) varies with age in different skeletal elements. Regression analysis was used to evaluate the relationship between age and osteon shape and size. We hypothesized that age would be negatively related to osteon size (area, On.Ar) and positively related to osteon shape (On.Cr). On.Cr and On.Ar were determined for the ribs and femora of 27 cadaveric specimens with known age-at-death. As predicted, age was significantly related to osteon size and shape for both the femur and rib. With age, there was a decrease in size and an increase in circularity. No relationship between sex and On.Cr was detected. An age predicting model, including On.Cr, On.Ar and OPD, is proposed to improve our ability to estimate age-at-death, especially for older individuals. PMID:27021159

  14. Histomorphometric Evaluation of the Small Coronary Arteries in Rats Exposed to Industrial Noise

    PubMed Central

    Lousinha, Ana; Antunes, Eduardo; Borrecho, Gonçalo; Oliveira, Maria João; Brito, José; Martins dos Santos, José

    2015-01-01

    Morphological changes induced by industrial noise (IN) have been experimentally observed in several organs. Histological observations of the coronary arteries showed prominent perivascular tissue and fibrosis among IN-exposed rats. The effects on the small arteries are unknown. Objective: To evaluate the histomorphometric changes induced by IN on rat heart small arteries. Methods: Twenty Wistar rats exposed to IN during a maximum period of seven months and 20 age-matched controls were studied. Hearts were transversely sectioned from ventricular apex to atria and a mid-ventricular fragment was selected for analysis. The histological images were obtained with an optical microscope using 400× magnifications. A total of 634 arterial vessels (298 IN-exposed and 336 controls) were selected. The mean lumen-to-vessel wall (L/W) and mean vessel wall-to-perivascular tissue (W/P) ratios were calculated using image J software. Results: There were no differences between exposed and control animals in their L/W ratios (p = 0.687) and time variations in this ratio were non-significant (p = 0.110). In contrast, exposed animals showed lower W/P ratios than control animals (p < 0.001), with significant time variations (p = 0.004). Conclusions: Industrial noise induced an increase in the perivascular tissue of rat small coronary arteries, with significant development of periarterial fibrosis. PMID:25946344

  15. Effect of Sodium Fluoride on Bone Biomechanical and Histomorphometric Parameters and on Insulin Signaling and Insulin Sensitivity in Ovariectomized Rats.

    PubMed

    de Cássia Alves Nunes, Rita; Chiba, Fernando Yamamoto; Pereira, Amanda Gomes; Pereira, Renato Felipe; de Lima Coutinho Mattera, Maria Sara; Ervolino, Edilson; Louzada, Mário Jefferson Quirino; Buzalaf, Marília Afonso Rabelo; Silva, Cristina Antoniali; Sumida, Doris Hissako

    2016-09-01

    Osteoporosis is a systemic disease characterized by bone degradation and decreased bone mass that promotes increased bone fragility and eventual fracture risk. Studies have investigated the use of sodium fluoride (NaF) for the treatment of osteoporosis. However, fluoride can alter glucose homeostasis. The aim of this study was to evaluate the effects of NaF intake (50 mg/L) from water on the following parameters of ovariectomized (OVX) rats: (1) tyrosine phosphorylation status of insulin receptor substrate (pp185 (IRS-1/IRS-2)) in white adipose tissue; (2) insulin sensitivity; (3) plasma concentrations of glucose, insulin, total cholesterol, triglyceride, TNF-α, IL-6, osteocalcin, calcium, and fluoride; (4) bone density and biomechanical properties in the tibia; and (5) tibia histomorphometric analysis. Fifty-two Wistar rats (2 months old) were ovariectomized and distributed into two groups: control group (OVX-C) and NaF group (OVX-F), which was subjected to treatment with NaF (50 mg/L) administered in drinking water for 42 days. The chronic treatment with NaF promoted (1) a decrease in pp185 (IRS-1/IRS-2) tyrosine phosphorylation status after insulin infusion in white adipose tissue and in insulin sensitivity; (2) an increase in the plasma concentration of insulin, fluoride, osteocalcin, calcium, triglyceride, VLDL-cholesterol, TNF-α, and IL-6; (3) a reduction in the trabecular width, bone area, stiffness, maximum strength, and tenacity; (4) no changes in body weight, food and water intake, plasma glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, bone mineral content, and bone mineral density. It was concluded that chronic treatment with NaF (50 mg/L) in OVX rats causes a decrease in insulin sensitivity, insulin signaling transduction, and biochemical, biomechanical, and histomorphometric bone parameters. PMID:26876375

  16. Histomorphometric analysis of irradiated recipient vessels and transplant vessels of free flaps in patients undergoing reconstruction after ablative surgery.

    PubMed

    Schultze-Mosgau, S; Erbe, M; Keilholz, L; Radespiel-Tröger, M; Wiltfang, J; Minge, N; Neukam, F W

    2000-04-01

    The aim of the study was to investigate, histomorphometrically, quantitative and qualitative changes in irradiated neck recipient vessels and transplant vessels used for microsurgical anastomoses in free flaps in patients undergoing preoperative radiotherapy and chemotherapy. In 55 patients receiving 42 radial forearm flaps, 6 latissimus dorsi flaps, 6 osteomyocutaneous fibula grafts and 1 lateral arm flap, a total of 220 vessels were obtained from neck recipient vessels and transplant vessels during anastomosis. Three groups were formed: Group 1 (16 patients) treated with no radiotherapy or chemotherapy; Group 2 (20 patients) treated with preoperative irradiation (40-50 Gy) and chemotherapy (800 mg/m2 5-FU and 20 mg/m2 cisplatin) 1.5 months prior to surgery; Group 3 (19 patients) treated with radiotherapy (60-70 Gy) (median interval 78.7 months; IQR 31.3 months) prior to surgery. From each of the 220 vessel specimens, 3 sections each were histomorphometrically investigated, both qualitatively and quantitatively. To evaluate these changes as a function of age, radiation dose and chemotherapy, a statistical analysis was performed using analysis of covariance and chi-square tests. In Group 3, qualitative changes (intima dehiscence, hyalinosis) were found in recipient arteries significantly more frequently (25%, P=0.009) than in Groups 1 and 2. For Group 3 recipient arteries, histomorphometry revealed a significant decrease in the ratio of media area/total vessel area (median 0.53, IQR 0.10) in comparison with Group 1 (P= 0.02) (median 0.60, IQR 0.29) and Group 2 (P=0.046) (median 0.59, IQR 0.10). No significant differences were found between the vessels of Groups 1 and 2 (P= 0.48). Age and chemotherapy did not appear to have a significant influence on vessel changes in this study. PMID:10833147

  17. Histomorphometric Evaluation of the Effects of Various Diode Lasers and Force Levels on Orthodontic Mini Screw Stability

    PubMed Central

    Isman, Eren; Taner, Lale; Kurkcu, Mehmet

    2015-01-01

    Abstract Objective The purpose of this study was to evaluate the effects of different laser dose and force levels on the stability of orthodontic mini screws used for anchorage, by histomorphometric analyses. Background data Low-level laser therapy speeds up blood flow, improves the mechanism of the revitalization processes, reduces the risk of infection, boosts metabolic activities, and accelerates the healing of the damaged tissue. Although there are many research studies about low-level laser therapy applications in a variety of areas, no investigations were found concerning mini screw stability using various laser dose levels with different force level applications. Methods Seventeen New Zealand white rabbits were used. A total of 68 cylindrical, self-drilling orthodontic mini screws were threaded at the fibula. Experimental subjects were divided into six groups; force application was not performed in the first three groups, whereas 150g of force was applied via nickel-titanium closed-coil springs placed between two mini screws in the other three groups. Measurements of the initial torque values (10 Ncm) were manipulated by a digital portable torque gauge. Various low-level laser doses were applied to the groups during the postoperative 10 days. After 4 weeks, bone-to-implant contact and cortical bone thickness were histomorphometrically analyzed. Results In the 150g force plus 20 J/cm2 dosage group, the highest bone-to-implant contact values were observed. (p<0.05) There were no statistically significant correlations between cortical bone thickness and bone-to-implant contact values; on the other hand, no significant difference was found among the same groups in terms of cortical bone thickness values (p>0.05). Conclusions Low-level laser therapy was noticed to induce the mini screw–bone contact area. Low-level laser therapy may be a supplementary treatment method to increase the stability of the orthodontic mini screw. PMID:25594769

  18. Histomorphometric comparison of the human, swine, and ovine collecting systems.

    PubMed

    Simões, Michele; de Souza, Diogo B; Gallo, Carla B M; Pereira-Sampaio, Marco A; Costa, Waldemar S; Sampaio, Francisco J

    2016-07-01

    The ovine kidney has been recently determined to be a better model than the swine kidney for the study of collecting system healing after partial nephrectomy. However, there is no histological study comparing the collecting systems of these species. To compare human, swine, and ovine collecting systems using histomorphometry. The collecting systems of 10 kidneys from each species (human, swine, and ovine) were processed for histomorphometry. The thickness of the three layers (mucosal connective tissue, submucosal muscular, and adventitial connective tissue) were measured. The densities of smooth muscle fibers, elastic system fibers, and cells were also measured. Additionally, blood vessel density in the adventitial connective tissue was measured. Analysis of the collecting systems from the three species presented several differences. The adventitial connective tissue from the swine samples was thicker, with more blood vessels and smooth muscle fibers, compared with that from the human and ovine samples. Swine also had higher density of elastic fibers on the submucosal muscular layer. Ovine and human collecting systems shared several similar features, such as blood vessel and elastic fiber density in all layers and the density of cellular and muscular fibers in the submucosal muscular and adventitial connective tissue layers. The collecting system of the ovine kidney is more similar to that of the human kidney compared with that of the swine kidney. This may explain the differences between the healing mechanisms in swine and those in humans and sheep after partial nephrectomy. Anat Rec, 299:967-972, 2016. © 2016 Wiley Periodicals, Inc. PMID:27111677

  19. Inner architecture of vertebral centra in terrestrial and aquatic mammals: a two-dimensional comparative study.

    PubMed

    Dumont, Maitena; Laurin, Michel; Jacques, Florian; Pellé, Eric; Dabin, Willy; de Buffrénil, Vivian

    2013-05-01

    Inner vertebral architecture is poorly known, except in human and laboratory animals. In order to document this topic at a broad comparative level, a 2D-histomorphometric study of vertebral centra was conducted in a sample of 98 therian mammal species, spanning most of the size range and representing the main locomotor adaptations known in therian taxa. Eleven variables relative to the development and geometry of trabecular networks were extracted from CT scan mid-sagittal sections. Phylogeny-informed statistical tests were used to reveal the respective influences of phylogeny, size, and locomotion adaptations on mammalian vertebral structure. The use of random taxon reshuffling and squared change parsimony reveals that 9 of the 11 characteristics (the two exceptions are total sectional area and structural polarization) contain a phylogenetic signal. Linear discriminant analyses suggest that the sampled taxa can be arranged into three categories with respect to locomotion mode: a) terrestrial + flying + digging + amphibious forms, b) coastal oscillatory aquatic taxa, and c) pelagic oscillatory aquatic forms represented by oceanic cetaceans. Pairwise comparison tests and linear regressions show that, when specific size increases, the length of trabecular network (Tt.Tb.Le), as well as trabecular proliferation in total sections (Pr.Tb.Tt), increase with positive allometry. This process occurs in all locomotion categories but is particularly pronounced in pelagic oscillators. Conversely, mean trabecular width has a lesser increase with size in pelagic oscillators. Trabecular orientation is not influenced by size. All tests were corrected for multiple testing. By using six structural variables or indices, locomotion mode can be predicted with a 97.4% success rate for terrestrial forms, 66.7% for coastal oscillatory, and 81.3% for pelagic oscillatory. The possible functional meaning of these results and their potential use for paleobiological inference of locomotion in

  20. Histomorphometric changes in the perirenal adipocytes of adrenalectomized rats treated with dexamethasone

    PubMed Central

    Ahmad, Fairus; Soelaiman, Ima Nirwana; Ramli, Elvy Suhana Mohd; Hooi, Tan Ming; Suhaimi, Farihah H

    2011-01-01

    INTRODUCTION: Prolonged steroid treatment administered to any patient can cause visceral obesity, which is associated with metabolic disease and Cushing's syndrome. Glucocorticoids have a profound negative effect on adipose tissue mass, giving rise to obesity, which in turn is regulated by the 11β-hydroxysteroid dehydrogenase type 1 enzyme. Adrenalectomized rats treated with dexamethasone exhibited an increase in visceral fat deposition but not in body weight. OBJECTIVES: The main aim of this study was to determine the effect of dexamethasone on the histomorphometric characteristics of perirenal adipocytes of adrenalectomized, dexamethasone-treated rats (ADR+Dexa) and the association of dexamethasone treatment with the expression and activity of 11β-hydroxysteroid dehydrogenase type 1 (11β- hydroxysteroid dehydrogenase type 1). METHODS: A total of 20 male Sprague Dawley rats were divided into 3 groups: a baseline control group (n = 6), a sham-operated group (n = 7) and an adrenalectomized group (n = 7). The adrenalectomized group was given intramuscular dexamethasone (ADR+Dexa) 2 weeks post adrenalectomy, and the rats from the sham-operated group were administered intramuscular vehicle (olive oil). RESULTS: Treatment with 120 µg/kg intramuscular dexamethasone for 8 weeks resulted in a significant decrease in the diameter of the perirenal adipocytes (p<0.05) and a significant increase in the number of perirenal adipocytes (p<0.05). There was minimal weight gain but pronounced fat deposition in the dexamethasone-treated rats. These changes in the perirenal adipocytes were associated with high expression and dehydrogenase activity of 11β-hydroxysteroid dehydrogenase type 1. CONCLUSIONS: In conclusion, dexamethasone increased the deposition of perirenal fat by hyperplasia, which causes increases in the expression and dehydrogenase activity of 11β-hydroxysteroid dehydrogenase type 1 in adrenalectomized rats. PMID:21789391

  1. Teaching the Comparative Approach to American Studies.

    ERIC Educational Resources Information Center

    Seaberg, Stanley

    The rationale behind this book of five suggested or sample comparative units contains several elements: 1) an interdisciplinary social science approach to studying the American past, present, and future; and 2) a view of our country's history in terms of a world setting and in the light on contemporary concerns. The global comparative method…

  2. Comparative Environmental Threat Analysis: Three Case Studies.

    ERIC Educational Resources Information Center

    Latour, J. B.; Reiling, R.

    1994-01-01

    Reviews how carrying capacity for different environmental problems is operationalized. Discusses whether it is possible to compare threats, using the exceeding of carrying capacity as a yardstick. Points out problems in comparative threat analysis using three case studies: threats to European groundwater resources, threats to ecosystems in Europe,…

  3. Comparative studies of gene regulatory mechanisms.

    PubMed

    Pai, Athma A; Gilad, Yoav

    2014-12-01

    It has become increasingly clear that changes in gene regulation have played an important role in adaptive evolution both between and within species. Over the past five years, comparative studies have moved beyond simple characterizations of differences in gene expression levels within and between species to studying variation in regulatory mechanisms. We still know relatively little about the precise chain of events that lead to most regulatory adaptations, but we have taken significant steps towards understanding the relative importance of changes in different mechanisms of gene regulatory evolution. In this review, we first discuss insights from comparative studies in model organisms, where the available experimental toolkit is extensive. We then focus on a few recent comparative studies in primates, where the limited feasibility of experimental manipulation dictates the approaches that can be used to study gene regulatory evolution. PMID:25215415

  4. The Use of Platelet-Rich Fibrin in Combination With Biphasic Calcium Phosphate in the Treatment of Bone Defects: A Histologic and Histomorphometric Study☆

    PubMed Central

    Bölükbaşı, Nilüfer; Yeniyol, Sinem; Tekkesin, Merva Soluk; Altunatmaz, Kemal

    2013-01-01

    Background Platelet-rich fibrin (PRF) is a leukocyte and platelet concentrate containing many growth factors. Its potential for hard tissue augmentation as a sole grafting material or in combination with other grafting materials has been investigated in many studies. Objective The aim of this histologic study was to evaluate the efficacy of PRF mixed with biphasic calcium phosphate (BCP) on bone regeneration in surgically created bone defects. Methods Defects 5 mm in diameter were created in both tibias of 6 sheep. The defects were left empty or grafted with BCP, PRF, or BCP+PRF. Animals were killed at 10, 20, and 40 days. The specimens underwent histologic and histomorphometric analysis. Results None of the groups displayed any signs of necrosis. Inflammation was observed in all groups at 10 days; 2 specimens of PRF+BCP and all empty defects showed inflammatory cell infiltration at 20 days. During the 40-day evaluation period, the PRF+BCP group showed the highest ratios of new bone. The other 3 groups showed statistically similar results. In the BCP and PRF+BCP groups, the residual graft ratios were decreased at consecutive time intervals. The difference between the 2 groups was not statistically significant during follow-up. Conclusions The current study revealed a histomorphometric increase in bone formation with the addition of PRF to BCP in surgically created defects in sheep tibia. PMID:24465037

  5. Histomorphometric evidence of deleterious effect of aluminum on osteoblasts.

    PubMed

    de Vernejoul, M C; Belenguer, R; Halkidou, H; Buisine, A; Bielakoff, J; Miravet, L

    1985-01-01

    Bone histomorphometry was performed in 26 hemodialyzed patients to study the relation between the dynamic parameters of bone formation and aluminum deposition. Patients were divided into two groups according to whether bone formation rate at tissue level (Svft) was above or below normal: 0.089 mu 3/mu 2 per day. The 12 patients who constituted group II, defined by a Svft less than 0.089 mu 3/mu 2 per day, had markedly decreased extent of double-labeled surfaces (m = 1.3 +/- 6.5%), and these were absent in 8 of 12 patients. Osteomalacia, defined by decreased formation with increased mean osteoid thickness (greater than 15 micron), was present in only 3 of 12 patients in group II. The 14 patients who constituted group I, defined by a Svft greater than 0.089 mu 3/mu 2 per day, had both increased total labeled surfaces and mineralization rate. Osteomalacia was present in none of the group I patients. In trabecular bone, group II patients had increased stainable aluminum deposition, compared to group I patients, whether estimated as total stainable aluminum (2.16 +/- 1.34 vs 0.17 +/- 0.28 mm/mm2) or stainable percent of trabecular surfaces (42 +/- 19 vs 4 +/- 5%). This last parameter was inversely related to osteoblastic surfaces (r = -0.49, n = 26, P less than 0.01) and total labeled surfaces (r = -0.72, n = 26, P less than 0.01). Therefore, massive aluminum deposition was not invariably associated with impaired mineralization but with decreased formation due to decreased extent of active formation surfaces. In the group I patients, moderate aluminum deposition was not associated with the mineralization arrest observed in these patients.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2581595

  6. The Influence of Low-Level Laser on Osseointegration Around Machined and Sandblasted Acid-Etched Implants: A Removal Torque and Histomorphometric Analyses.

    PubMed

    Teixeira, Eduardo Rolim; Torres, Marco Antônio Rambo Osório; Meyer, Kleber Ricardo Monteiro; Zani, Sabrina Rebollo; Shinkai, Rosemary Sadami Arai; Grossi, Márcio Lima

    2015-08-01

    Evaluation of the influence of laser application on osseointegration around implants with different surface characteristics is limited. This study aims to evaluate the influence of low-level lasers on the early stages of osseointegration. Ninety-six external hex implants (3.75 mm × 5.0 mm) were placed in 24 rabbits-one machined and one sandblasted acid-etched per tibia. The rabbits were later divided into the laser group, which received a total dose of 24 J/cm(2) of gallium-aluminum-arsenide laser over 15 days, and a control group. At 16 and 30 days after surgery, removal torque and histomorphometric analyses were performed. No statistical differences in removal torque or histomorphometric analyses were verified between laser and control groups regardless of implant surface (P > .05). Time was the only variable presenting significant differences between measurements (P < .05). Low-level laser had no significant short-term effect on bone-to-implant contact and removal torque values regardless of implant surface characteristics. PMID:23834724

  7. Species comparative studies and cognitive development.

    PubMed

    Gómez, Juan-Carlos

    2005-03-01

    The comparative study of infant development and animal cognition brings to cognitive science the promise of insights into the nature and origins of cognitive skills. In this article, I review a recent wave of comparative studies conducted with similar methodologies and similar theoretical frameworks on how two core components of human cognition--object permanence and gaze following--develop in different species. These comparative findings call for an integration of current competing accounts of developmental change. They further suggest that evolution has produced developmental devices capable at the same time of preserving core adaptive components, and opening themselves up to further adaptive change, not only in interaction with the external environment, but also in interaction with other co-developing cognitive systems. PMID:15737820

  8. A Comparative Study of Sparse Associative Memories

    NASA Astrophysics Data System (ADS)

    Gripon, Vincent; Heusel, Judith; Löwe, Matthias; Vermet, Franck

    2016-05-01

    We study various models of associative memories with sparse information, i.e. a pattern to be stored is a random string of 0s and 1s with about log N 1s, only. We compare different synaptic weights, architectures and retrieval mechanisms to shed light on the influence of the various parameters on the storage capacity.

  9. The Student Teaching Experience: A Comparative Study.

    ERIC Educational Resources Information Center

    Butler, Judy D.

    This paper describes a 1996 study that compared the student teaching experiences of a traditional and a nontraditional student to ascertain what differences in their experiences might imply about teacher preparation. The two students kept journals that could be written in at any time of the day. They recorded their impressions of their situation…

  10. A Comparative Study of Sparse Associative Memories

    NASA Astrophysics Data System (ADS)

    Gripon, Vincent; Heusel, Judith; Löwe, Matthias; Vermet, Franck

    2016-07-01

    We study various models of associative memories with sparse information, i.e. a pattern to be stored is a random string of 0s and 1s with about log N 1s, only. We compare different synaptic weights, architectures and retrieval mechanisms to shed light on the influence of the various parameters on the storage capacity.

  11. Intramembranous Bone Healing Process Subsequent to Tooth Extraction in Mice: Micro-Computed Tomography, Histomorphometric and Molecular Characterization

    PubMed Central

    Vieira, Andreia Espindola; Repeke, Carlos Eduardo; Ferreira Junior, Samuel de Barros; Colavite, Priscila Maria; Biguetti, Claudia Cristina; Oliveira, Rodrigo Cardoso; Assis, Gerson Francisco; Taga, Rumio; Trombone, Ana Paula Favaro; Garlet, Gustavo Pompermaier

    2015-01-01

    Bone tissue has a significant potential for healing, which involves a significant the interplay between bone and immune cells. While fracture healing represents a useful model to investigate endochondral bone healing, intramembranous bone healing models are yet to be developed and characterized. In this study, a micro-computed tomography, histomorphometric and molecular (RealTimePCRarray) characterization of post tooth-extraction alveolar bone healing was performed on C57Bl/6 WT mice. After the initial clot dominance (0h), the development of a provisional immature granulation tissue is evident (7d), characterized by marked cell proliferation, angiogenesis and inflammatory cells infiltration; associated with peaks of growth factors (BMP-2-4-7,TGFβ1,VEGFa), cytokines (TNFα, IL-10), chemokines & receptors (CXCL12, CCL25, CCR5, CXCR4), matrix (Col1a1-2, ITGA4, VTN, MMP1a) and MSCs (CD105, CD106, OCT4, NANOG, CD34, CD146) markers expression. Granulation tissue is sequentially replaced by more mature connective tissue (14d), characterized by inflammatory infiltrate reduction along the increased bone formation, marked expression of matrix remodeling enzymes (MMP-2-9), bone formation/maturation (RUNX2, ALP, DMP1, PHEX, SOST) markers, and chemokines & receptors associated with healing (CCL2, CCL17, CCR2). No evidences of cartilage cells or tissue were observed, strengthening the intramembranous nature of bone healing. Bone microarchitecture analysis supports the evolving healing, with total tissue and bone volumes as trabecular number and thickness showing a progressive increase over time. The extraction socket healing process is considered complete (21d) when the dental socket is filled by trabeculae bone with well-defined medullary canals; it being the expression of mature bone markers prevalent at this period. Our data confirms the intramembranous bone healing nature of the model used, revealing parallels between the gene expression profile and the histomorphometric

  12. Effects of Spirulina on Cyclophosphamide-Induced Ovarian Toxicity in Rats: Biochemical and Histomorphometric Evaluation of the Ovary

    PubMed Central

    Yener, Nese Arzu; Sinanoglu, Orhun; Ilter, Erdin; Celik, Aygen; Sezgin, Gulbuz; Midi, Ahmet; Aksungar, Fehime

    2013-01-01

    Cyclophosphamide (Cyc) is known to cause ovotoxicity and infertility in women. Our aim is to investigate the possible ovotoxic effects of Cyc and possible antioxidant and protective effects of blue-green algae, Spirulina (Sp), in rat ovaries. Eighteen rats were given: group I (n = 6, control); group II (n = 6, CP), a single dose Cyc; group III (n = 6, Sp+Cyc), 7 days Sp+single dose Cyc. Tissue malondialdehyde (MDA) levels, superoxide dismutase (SOD), and catalase (CAT) activities are assessed biochemically. Normal and atretic primordial and primary follicle counts for all sections obtained for each ovary are calculated. Mean number of follicle counts for each group are compared. In Sp+Cyc group, tissue MDA levels were significantly lower than those in the CP and higher than those in the C group (CP > Sp+Cyc > C). Tissue SOD activity was significantly higher in Sp+Cyc group than that in the CP group and lower than that in the C group (C > Sp+Cyc > C). No statistically significant difference was found between the ovarian CAT activities in any group. Histomorphometrically, there was also no significant difference between the mean numbers of normal and atretic small follicle counts. Our results suggest that single dose Cyc has adverse effects on oxidant status of the ovaries and Sp has protective effects in Cyc-induced ovotoxicity. PMID:23762559

  13. Electrophysiological evaluation of nerve function in inferior alveolar nerve injury: relationship between nerve action potentials and histomorphometric observations.

    PubMed

    Murayama, M; Sasaki, K; Shibahara, T

    2015-12-01

    The objective of this study was to improve the accuracy of diagnosis of inferior alveolar nerve (IAN) injury by determining degrees of nerve disturbance using the sensory nerve action potential (SNAP) and sensory nerve conduction velocity (SCV). Crush and partial and complete nerve amputation injuries were applied to the IAN of rabbits, then SNAPs and histomorphometric observations were recorded at 1, 5, and 10 weeks. For crush injury, most nerves were smaller in diameter at 5 weeks than at 1 week, however after 10 weeks, extensive nerve regeneration was observed. The SNAP showed a decrease in SCV at weeks 1 and 5, followed by an increase at week 10. For partial nerve amputation, small to medium-sized nerve fibres were observed at weeks 1 and 5, then larger nerves were seen at week 10. Minimal changes in SCV were observed at weeks 1 and 5, however SCV increased at week 10. For complete nerve amputation, nerve fibres were sparse at week 1, but gradual nerve regeneration was observed at weeks 5 and 10. SNAPs were detectable from week 10, however the SCV was extremely low. This study showed SCV to be an effective factor in the evaluation of nerve injury and regeneration. PMID:26433750

  14. Histomorphometric analysis of collagen and elastic fibres in the cranial and caudal fold of the porcine glottis.

    PubMed

    Lang, A; Koch, R; Rohn, K; Gasse, H

    2015-06-01

    The porcine glottis differs from the human glottis in its cranial and caudal vocal folds (CraF, CauF). The fibre apparatus of these folds was studied histomorphometrically in adult minipigs. For object definition and quantification, the colour-selection tools of the Adobe-Photoshop program were used. Another key feature was the subdivision of the cross-sections of the folds into proportional subunits. This allowed a statistical analysis irrespective of differences in thickness of the folds. Both folds had a distinct, dense subepithelial layer equivalent to the basement membrane zone in humans. The subsequent, loose layer was interpreted - in principle - as being equivalent to Reinke's space of the human vocal fold. The next two layers were not clearly separated. Due to this, the concept of a true vocal ligament did not appear applicable to neither CauF nor CraF. Instead, the body-cover model was emphasized by our findings. The missing vocalis muscle in the CraF is substituted by large collagen fibre bundles in a proportional depth corresponding to the position of the muscle of the CauF. The distribution of elastic fibres made the CraF rather than the CauF more similar to the human vocal fold. We suggest that these data are useful for those wishing to use the porcine glottis as a model for studying oscillatory properties during phonation. PMID:24995486

  15. Evaluating synteny for improved comparative studies

    PubMed Central

    Ghiurcuta, Cristina G.; Moret, Bernard M. E.

    2014-01-01

    Motivation: Comparative genomics aims to understand the structure and function of genomes by translating knowledge gained about some genomes to the object of study. Early approaches used pairwise comparisons, but today researchers are attempting to leverage the larger potential of multi-way comparisons. Comparative genomics relies on the structuring of genomes into syntenic blocks: blocks of sequence that exhibit conserved features across the genomes. Syntenic blocs are required for complex computations to scale to the billions of nucleotides present in many genomes; they enable comparisons across broad ranges of genomes because they filter out much of the individual variability; they highlight candidate regions for in-depth studies; and they facilitate whole-genome comparisons through visualization tools. However, the concept of syntenic block remains loosely defined. Tools for the identification of syntenic blocks yield quite different results, thereby preventing a systematic assessment of the next steps in an analysis. Current tools do not include measurable quality objectives and thus cannot be benchmarked against themselves. Comparisons among tools have also been neglected—what few results are given use superficial measures unrelated to quality or consistency. Results: We present a theoretical model as well as an experimental basis for comparing syntenic blocks and thus also for improving or designing tools for the identification of syntenic blocks. We illustrate the application of the model and the measures by applying them to syntenic blocks produced by three different contemporary tools (DRIMM-Synteny, i-ADHoRe and Cyntenator) on a dataset of eight yeast genomes. Our findings highlight the need for a well founded, systematic approach to the decomposition of genomes into syntenic blocks. Our experiments demonstrate widely divergent results among these tools, throwing into question the robustness of the basic approach in comparative genomics. We have taken

  16. [Histomorphometric characteristic of human brain in acute alcoholic intoxication].

    PubMed

    Shormanov, S V; Shormanova, N S

    2005-01-01

    Different brain sections were studied in 20 subjects, who died of ethanol intoxication and in 14 subjects who died of injuries of the heart and main vessels, in order to detect histological changes in the brain and for the purpose of defining spatial and quantitative ratios between cerebral tissue structures in alcoholic intoxication. Different histological, stereometric and morphometric tools were made use of. It was demonstrated that, in alcoholic intoxication, there occur severe disorders of the circulation with affection of vessels in the brain; there are also dystrophic and necrotic changes in neurocytes, glial cells and white substance. The square of neurons shrinks due to death of some of them in the cortex of hemispheres, thalamus and cerebellum. As for the medulla, they are more resistant, there, to ethanol. The diameter of capillaries in the studied brain sections diminishes due to a reduced tonus of cerebral arteries; the quantity of such vessels increases within a standard area, which is conditioned by the compensatory opening of reserve capillaries. All this can be important in dealing with issues of thanatogenesis and of forensic medical diagnosis in death of alcoholic intoxication. PMID:15881135

  17. Doxofylline and Theophylline: A Comparative Clinical Study

    PubMed Central

    Akram, MD Faiz; Nasiruddin, Mohammad; Ahmad, Zuber; Ali Khan, Rahat

    2012-01-01

    Objectives COPD is one of the major public health problems worldwide. Theophylline has been used in the treatment of COPD for decades. Doxofylline a new theophylline congener has been claimed to have better safety profile. The study was undertaken to compare theophylline and doxophylline at doses recommended and commonly used in clinical practice. Methods The study was conducted in patients of COPD in TB chest department of a medical college hospital. It was randomized, prospective and open label. A total of 154 patients were divided in two group .Group I was administered 400 mg theophylline SR once daily and group II was administered doxofylline 400 mg twice a day orally. Spirometric variables symptom score, and adverse effects were recorded on day 0, 7 and 21 of therapy. Data were compared and analysed using SPSS version 16. Results Results of the study showed that there was no statistically significant difference with respect to spirometric variables and symptom score in the two groups and there was no significant difference in two groups with respect to side effects (p>0.05). Conclusions It is concluded that doxophylline has no advantage over theophylline in terms of either efficacy or safety on the doses commonly used in current clinical practice. PMID:23373027

  18. Comparative study of INPIStron and spark gap

    NASA Technical Reports Server (NTRS)

    Han, Kwang S.; Lee, Ja H.

    1993-01-01

    An inverse pinch plasma switch, INPIStron, was studied in comparison to a conventional spark gap. The INPIStron is under development for high power switching applications. The INPIStron has an inverse pinch dynamics, opposed to Z-pinch dynamics in the spark gap. The electrical, plasma dynamics and radiative properties of the closing plasmas have been studied. Recently the high-voltage pulse transfer capabilities or both the INPIStron and the spark gap were also compared. The INPIStron with a low impedance Z = 9 ohms transfers 87 percent of an input pulse with a halfwidth of 2 mu s. For the same input pulse the spark gap of Z = 100 ohms transfers 68 percent. Fast framing and streak photography, taken with an TRW image converter camera, was used to observe the discharge uniformity and closing plasma speed in both switches. In order to assess the effects of closing plasmas on erosion of electrode material, emission spectra of two switches were studied with a spectrometer-optical multi channel analyzer (OMA) system. The typical emission spectra of the closing plasmas in the INPIStron and the spark gap showed that there were comparatively weak carbon line emission in 658.7 nm and copper (electrode material) line emissions in the INPIStron, indicating low erosion of materials in the INPIStron.

  19. EFQPSK Versus CERN: A Comparative Study

    NASA Technical Reports Server (NTRS)

    Borah, Deva K.; Horan, Stephen

    2001-01-01

    This report presents a comparative study on Enhanced Feher's Quadrature Phase Shift Keying (EFQPSK) and Constrained Envelope Root Nyquist (CERN) techniques. These two techniques have been developed in recent times to provide high spectral and power efficiencies under nonlinear amplifier environment. The purpose of this study is to gain insights into these techniques and to help system planners and designers with an appropriate set of guidelines for using these techniques. The comparative study presented in this report relies on effective simulation models and procedures. Therefore, a significant part of this report is devoted to understanding the mathematical and simulation models of the techniques and their set-up procedures. In particular, mathematical models of EFQPSK and CERN, effects of the sampling rate in discrete time signal representation, and modeling of nonlinear amplifiers and predistorters have been considered in detail. The results of this study show that both EFQPSK and CERN signals provide spectrally efficient communications compared to filtered conventional linear modulation techniques when a nonlinear power amplifier is used. However, there are important differences. The spectral efficiency of CERN signals, with a small amount of input backoff, is significantly better than that of EFQPSK signals if the nonlinear amplifier is an ideal clipper. However, to achieve such spectral efficiencies with a practical nonlinear amplifier, CERN processing requires a predistorter which effectively translates the amplifier's characteristics close to those of an ideal clipper. Thus, the spectral performance of CERN signals strongly depends on the predistorter. EFQPSK signals, on the other hand, do not need such predistorters since their spectra are almost unaffected by the nonlinear amplifier, Ibis report discusses several receiver structures for EFQPSK signals. It is observed that optimal receiver structures can be realized for both coded and uncoded EFQPSK

  20. A Comparative Study of Mammalian Diversification Pattern

    PubMed Central

    Yu, Wenhua; Xu, Junxiao; Wu, Yi; Yang, Guang

    2012-01-01

    Although mammals have long been regarded as a successful radiation, the diversification pattern among the clades is still poorly known. Higher-level phylogenies are conflicting and comprehensive comparative analyses are still lacking. Using a recently published supermatrix encompassing nearly all extant mammalian families and a novel comparative likelihood approach (MEDUSA), the diversification pattern of mammalian groups was examined. Both order- and family-level phylogenetic analyses revealed the rapid radiation of Boreoeutheria and Euaustralidelphia in the early mammalian history. The observation of a diversification burst within Boreoeutheria at approximately 100 My supports the Long Fuse model in elucidating placental diversification progress, and the rapid radiation of Euaustralidelphia suggests an important role of biogeographic dispersal events in triggering early Australian marsupial rapid radiation. Diversification analyses based on family-level diversity tree revealed seven additional clades with exceptional diversification rate shifts, six of which represent accelerations in net diversification rate as compared to the background pattern. The shifts gave origin to the clades Muridae+Cricetidae, Bovidae+Moschidae+Cervidae, Simiiformes, Echimyidae, Odontoceti (excluding Physeteridae+Kogiidae+Platanistidae), Macropodidae, and Vespertilionidae. Moderate to high extinction rates from background and boreoeutherian diversification patterns indicate the important role of turnovers in shaping the heterogeneous taxonomic richness observed among extant mammalian groups. Furthermore, the present results emphasize the key role of extinction on erasing unusual diversification signals, and suggest that further studies are needed to clarify the historical radiation of some mammalian groups for which MEDUSA did not detect exceptional diversification rates. PMID:22457604

  1. Comparative Study of Vented vs. Unvented Crawlspaces

    SciTech Connect

    Biswas, Kaushik; Christian, Jeffrey E; Gehl, Anthony C

    2011-10-01

    There has been a significant amount of research in the area of building energy efficiency and durability. However, well-documented quantitative information on the impact of crawlspaces on the performance of residential structures is lacking. The objective of this study was to evaluate and compare the effects of two crawlspace strategies on the whole-house performance of a pair of houses in a mixed humid climate. These houses were built with advanced envelope systems to provide energy savings of 50% or more compared to traditional 2010 new construction. One crawlspace contains insulated walls and is sealed and semi-conditioned. The other is a traditional vented crawlspace with insulation in the crawlspace ceiling. The vented (traditional) crawlspace contains fiberglass batts installed in the floor chase cavities above the crawl, while the sealed and insulated crawlspace contains foil-faced polyisocyanurate foam insulation on the interior side of the masonry walls. Various sensors to measure temperatures, heat flux through crawlspace walls and ceiling, and relative humidity were installed in the two crawlspaces. Data from these sensors have been analyzed to compare the performance of the two crawlspace designs. The analysis results indicated that the sealed and insulated crawlspace design is better than the traditional vented crawlspace in the mixed humid climate.

  2. Bone histomorphometric analysis in a patient with anorexia nervosa.

    PubMed

    Hiramatsu, Rikako; Ubara, Yoshifumi; Suwabe, Tatsuya; Hoshino, Junichi; Sumida, Keiichi; Hasegawa, Eiko; Yamanouchi, Masayuki; Hayami, Noriko; Sawa, Naoki; Takaichi, Kenmei

    2013-09-01

    A 34-year-old Japanese woman with anorexia nervosa (AN) of a body mass index (BMI) of 11.0 kg/cm(2) was admitted to our hospital for assessment of renal dysfunction with a serum creatinine of 1.8 mg/dL and hypokalemia (3.0 mEq/L). Renal biopsy showed chronic interstitial fibrosis with hypertrophy of the juxtaglomerular apparatus. Iliac crest biopsy was performed because of a severe decrease in bone mineral density. It showed active resorption at the periosteal and endosteal surfaces of cortical bone by numerous osteoclasts, as well as bone island formation in cancellous bone due to marked decrease of trabecular connections. A dynamic study using double labeling showed that mineralization of cancellous bone adjacent to cortical bone occurred between the first and second labelings, but did not occur between the second labeling and osteoid formation during the 28-day period before biopsy, which implied that the mineralization was related to promotion of food intake after hospitalization, while the lack of mineralization was due to poor food intake outside hospital. Empty lacunae that indicated the death of osteocytes were seen. Because her bone mass and kidney injury improved after weight gain and normokalemia were achieved by a highly nutritious diet, malnutrition with hypokalemia may have a negative influence on bone formation due to impaired mineralization and may activate bone resorption by osteoclasts secondary to the formation of empty lacunae. This is the first report about the histological features of premenopausal osteoporosis in a patient with AN and kidney injury. PMID:23726962

  3. Comparative study of heart sound localization algorithms

    NASA Astrophysics Data System (ADS)

    Moukadem, A.; Dieterlen, A.; Hueber, N.; Brandt, C.; Raymond, P.

    2011-05-01

    The purpose of this document is to present a comparative study of five algorithms of heart sound localization, one of which, is a method based on radial basis function networks applied in a novel approach. The advantages and disadvantages of each method are evaluated according to a data base of 50 subjects in which there are 25 healthy subjects selected from the University Hospital of Strasbourg (HUS) and from theMARS500 project (Moscow) and 25 subjects with cardiac pathologies selected from the HUS. This study is made under the control of an experienced cardiologist. The performance of each method is evaluated by calculating the area under a receiver operating curve (AUC) and the robustness is shown against different levels of additive white Gaussian noise.

  4. Pairing Fluctuations Above Tc: A Comparative Study

    NASA Astrophysics Data System (ADS)

    Verga, Simona; Gooding, Robert J.; Marsiglio, Frank

    2003-03-01

    Although the investigation of superconductivity in High Tc Cuprates has been extensive, its microscopic origin is still under debate. An important experimental fact is the universality of many properties of the cuprates (the low dimensionality, the d-wave symmetry of the superconducting gap and the pseudogap), which must be reproduced by any competitive theory. While there is no consensus about the 'glue' that binds two electrons in a pair, one can gain insight by simply providing it, without questioning its nature. The Attractive Hubbard Model for electrons on a lattice provides the means for such an approach, but even if it simplifies the picture considerably, in the coupling regime of interest one needs to rely on approximate theories. We present a comparative study of different versions of the T-matrix approximation in the atomic limit (strong coupling), where the existence of analytical solutions enables us to test how well the approximations work. We also employ a non-perturbative approach due to Y. M. Vilk and A.-M. S. Tremblay and compare it with the T-matrix and the analytical solutions. We discuss the relevance of such a study for other coupling regimes and more realistic models.

  5. Scatterometry or imaging overlay: a comparative study

    NASA Astrophysics Data System (ADS)

    Hsu, Simon C. C.; Pai, Yuan Chi; Chen, Charlie; Yu, Chun Chi; Hsing, Henry; Wu, Hsing-Chien; Kuo, Kelly T. L.; Amir, Nuriel

    2015-03-01

    Most fabrication facilities today use imaging overlay measurement methods, as it has been the industry's reliable workhorse for decades. In the last few years, third-generation Scatterometry Overlay (SCOL™) or Diffraction Based Overlay (DBO-1) technology was developed, along another DBO technology (DBO-2). This development led to the question of where the DBO technology should be implemented for overlay measurements. Scatterometry has been adopted for high volume production in only few cases, always with imaging as a backup, but scatterometry overlay is considered by many as the technology of the future. In this paper we compare imaging overlay and DBO technologies by means of measurements and simulations. We outline issues and sensitivities for both technologies, providing guidelines for the best implementation of each. For several of the presented cases, data from two different DBO technologies are compared as well, the first with Pupil data access (DBO-1) and the other without pupil data access (DBO-2). Key indicators of overlay measurement quality include: layer coverage, accuracy, TMU, process robustness and robustness to process changes. Measurement data from real cases across the industry are compared and the conclusions are also backed by simulations. Accuracy is benchmarked with reference OVL, and self-consistency, showing good results for Imaging and DBO-1 technology. Process sensitivity and metrology robustness are mostly simulated with MTD (Metrology Target Designer) comparing the same process variations for both technologies. The experimental data presented in this study was done on ten advanced node layers and three production node layers, for all phases of the IC fabrication process (FEOL, MEOL and BEOL). The metrology tool used for most of the study is KLA-Tencor's Archer 500LCM system (scatterometry-based and imaging-based measurement technologies on the same tool) another type of tool is used for DBO-2 measurements. Finally, we conclude that

  6. Protection against T1DM-Induced Bone Loss by Zinc Supplementation: Biomechanical, Histomorphometric, and Molecular Analyses in STZ-Induced Diabetic Rats

    PubMed Central

    Bortolin, Raul Hernandes; da Graça Azevedo Abreu, Bento João; Abbott Galvão Ururahy, Marcela; Costa de Souza, Karla Simone; Bezerra, João Felipe; Bezerra Loureiro, Melina; da Silva, Flávio Santos; Marques, Dáfiny Emanuele da Silva; Batista, Angélica Amanda de Sousa; Oliveira, Gisele; Luchessi, André Ducati; Lima, Valéria Morgiana Gualberto Duarte Moreira; Miranda, Carlos Eduardo Saraiva; Lia Fook, Marcus Vinicius; Almeida, Maria das Graças; de Rezende, Luciana Augusto; de Rezende, Adriana Augusto

    2015-01-01

    Several studies have established an association between diabetes and alterations in bone metabolism; however, the underlying mechanism is not well established. Although zinc is recognized as a potential preventive agent against diabetes-induced bone loss, there is no evidence demonstrating its effect in chronic diabetic conditions. This study evaluated the effects of zinc supplementation in a chronic (90 days) type 1 diabetes-induced bone-loss model. Male Wistar rats were distributed in three groups: control, type 1 diabetes mellitus (T1DM), and T1DM plus zinc supplementation (T1DMS). Serum biochemical analysis; tibia histomorphometric, biomechanical, and collagen-content analyses; and femur mRNA expression were evaluated. Relative to T1DM, the zinc-supplemented group showed increased histomorphometric parameters such as TbWi and BAr and decreased TbSp, increased biomechanical parameters (maximum load, stiffness, ultimate strain, and Young’s modulus), and increased type I collagen content. Interestingly, similar values for these parameters were observed between the T1DMS and control groups. These results demonstrate the protective effect of zinc on the maintenance of bone strength and flexibility. In addition, downregulation of OPG, COL1A, and MMP-9 genes was observed in T1DMS, and the anabolic effects of zinc were evidenced by increased OC expression and serum ALP activity, both related to osteoblastogenesis, demonstrating a positive effect on bone formation. In contrast, T1DM showed excessive bone loss, observed through reduced histomorphometric and biomechanical parameters, characterizing diabetes-associated bone loss. The bone loss was also observed through upregulation of OPG, COL1A, and MMP-9 genes. In conclusion, zinc showed a positive effect on the maintenance of bone architecture and biomechanical parameters. Indeed, OC upregulation and control of expression of OPG, COL1A, and MMP-9 mRNAs, even in chronic hyperglycemia, support an anabolic and protective

  7. A comparative study on monitored anesthesia care

    PubMed Central

    Sen, Jayashree; Sen, Bitan

    2014-01-01

    Aim: The aim of this study is to compare the effectiveness, hemodynamic changes and duration of sedation and analgesia between combinations of fortwin-phenergan-midazolam (FPM) and ketamine - midazolam (KM) along with local anesthesia for the surgeries done under the umbrella of monitored anesthesia care. Materials and Methods: A total of 50 patients undergoing surgeries as tympanoplasty, septoplasty, lip repair, dacrocystectomy and cataract under local anesthesia, randomly received either intravenous (IV) fortwin 0.3 mg/kg over 1 min followed by IV midazolam 0.04 mg/kg plus IV phenergan 12.5 mg (Group FPM) or IV ketamine 0.3 mg/kg over 1 min plus IV midazolam 0.04 mg/kg (Group KM). Sedation was titrated to Ramsay sedation score (RSS) of 3. Patients’ mean arterial pressure (MAP), heart rate (HR), saturation peripheral pulse, duration of sedation and need for intraoperative rescue sedation/analgesic were recorded and compared. Satisfaction of patients (using a 1-7 point Likert verbal rating scale) and readiness for discharge towards (time to Aldrete score of 10) were also determined. Result: Group KM had significant rise in HR (20-25%) and MAP (25-30%) from 30 min after the bolus dose given until the end of the surgery in contrast to Group FPM. The target sedation level (RSS ≥ 3) was higher in Group FPM (n = 23 [92%]) as compared with Group KM (n = 12 [48%]). Time until need for rescue sedation was 66.96 ± 17.19 min in FPM and 32.80 ± 8.90 min in KM group. The patient satisfaction (Likert scale) is more with the FPM group (6.12 ± 0.83 vs. 4.40 ± 1.20). Conclusion: We found that the combination of FPM is superior to the KM combination as per the hemodynamic changes, duration of analgesia, patients’ satisfaction and efficacy of the drugs are concerned. PMID:25886327

  8. Water Ice in Comets: A Comparative Study

    NASA Astrophysics Data System (ADS)

    Protopapa, Silvia; Sunshine, J.; Feaga, L. M.; Kelley, M. S.; A'Hearn, M. F.; Farnham, T.; DIXI Team

    2013-06-01

    Processes involving the sublimation of volatiles dominate cometary activity and drive the release of ancient material from within the nucleus into the coma. As comets are kept cold for most of their history, they contain the least processed primordial materials that accumulated into the giant planets. In addition, comets may have delivered their ices and organics to the primitive Earth. The Deep Impact eXtended Investigation (DIXI) to comet Hartley 2 revealed a highly active comet with bright icy-rich jets. We present a detailed characterization of the composition and texture of the ices and refractories in the inner-most coma of Hartley 2, closer than a few kilometers from the surface. This analysis is conducted using laboratory measurements of optical constants of cometary analog materials. We also discuss the implications of these findings on the accretion process that led to the formation of cometary nuclei and therefore of planets. The physical makeup of the ice grains in comet Hartley 2 is compared with that of water ice in the interior, surface, and coma of other comets (e.g., 9P/Tempel 1, C/2002 T7 (LINEAR), 17P/Holmes). Through this comparative study, we investigate how ice is redistributed from the interior to the surface and ultimately into the coma of comets.

  9. Comparative Study of Airfoil Flow Separation Criteria

    NASA Astrophysics Data System (ADS)

    Laws, Nick; Kahouli, Waad; Epps, Brenden

    2015-11-01

    Airfoil flow separation impacts a multitude of applications including turbomachinery, wind turbines, and bio-inspired micro-aerial vehicles. In order to achieve maximum performance, some devices operate near the edge of flow separation, and others use dynamic flow separation advantageously. Numerous criteria exist for predicting the onset of airfoil flow separation. This talk presents a comparative study of a number of such criteria, with emphasis paid to speed and accuracy of the calculations. We evaluate the criteria using a two-dimensional unsteady vortex lattice method, which allows for rapid analysis (on the order of seconds instead of days for a full Navier-Stokes solution) and design of optimal airfoil geometry and kinematics. Furthermore, dynamic analyses permit evaluation of dynamic stall conditions for enhanced lift via leading edge vortex shedding, commonly present in small flapping-wing flyers such as the bumblebee and hummingbird.

  10. Comparative microscopy study of Vibrio cholerae flagella

    NASA Astrophysics Data System (ADS)

    Konnov, Nikolai P.; Baiburin, Vil B.; Zadnova, Svetlana P.; Volkov, Uryi P.

    1999-06-01

    A fine structure of bacteria flagella is an important problem of molecular cell biology. Bacteria flagella are the self-assembled structures that allow to use the flagellum protein in a number of biotechnological applications. However, at present, there is a little information about high resolution scanning probe microscopy study of flagellum structure, in particular, about investigation of Vibrio cholerae flagella. In our lab have been carried out the high resolution comparative investigation of V. cholerae flagella by means of various microscopes: tunneling (STM), scanning force (SFM) and electron transmission. As a scanning probe microscope is used designed in our lab versatile SPM with replaceable measuring heads. Bacteria were grown, fixed and treated according to the conventional techniques. For STM investigations samples were covered with Pt/Ir thin films by rotated vacuum evaporation, in SFM investigations were used uncovered samples. Electron microscopy of the negatively stained bacteria was used as a test procedure.

  11. Supracostal percutaneous nephrolithotomy: A prospective comparative study

    PubMed Central

    Sinha, Maneesh; Krishnappa, Pramod; Subudhi, Santosh Kumar; Krishnamoorthy, Venkatesh

    2016-01-01

    Introduction: A widely prevalent fear of thoracic complications with the supracostal approach has led to its underutilization in percutaneous nephrolithotomy (PCNL). We frequently use the supracostal approach and compared the efficacy and thoracic complications of infracostal, supra 12th, and supra 11th punctures. Materials and Methods: This was a prospective study of patients who underwent PCNL between January 2005 and December 2012. The patients were divided into three groups based on the access: infracostal, supra 12th (between the 11th and 12th ribs) and supra 11th (between the 10th and 11th ribs). Clearance rates, fall in hemoglobin levels, transfusion rates, perioperative analgesic requirements, hospital stay and thoracic complications were compared. Results: Seven hundred patients were included for analysis. There were 179 (25.5%) patients in the supra 11th group, 187 (26.7%) patients in the supra 12th group and 334 (47.8%) patients in the infracostal group. The overall clearance rate was 78% with no difference in the three groups. The postoperative analgesic requirements were significantly higher in the supracostal groups and showed a graded increase from infracostal to supra 12th to supra 11th. During the study period, only 2 patients required angioembolization (0.3%) and none required open exploration. The number of patients requiring intercostal chest drain insertion was extremely low, at 1.6% and 2.2% in the supra 12th and supra 11th groups, respectively. Conclusions: Our results confirm the feasibility of the supracostal approach including punctures above the 11th rib, albeit at the cost of an increase in thoracic complications. Staying in the line of the calyx has helped us to minimize the most dreaded complication of bleeding requiring angioembolization. PMID:26941494

  12. Comparative study of pressure-flow parameters.

    PubMed

    Eri, Lars M; Wessel, Nicolai; Tysland, Ole; Berge, Viktor

    2002-01-01

    Methods for quantification of bladder outlet obstruction (BOO) are still controversial. Parameters such as detrusor opening pressure (p(det.open)), maximum detrusor pressure (p(det.max)), minimum voiding pressure (p(det.min.void)), and detrusor pressure at maximum flow rate (P(det.Qmax)) separate obstructed from nonobstructed patients to some extent, but two nomograms, the Abrams-Griffiths nomogram and the linearized passive urethral resistance relation (LinPURR), are more accepted for this purpose, along with the urethral resistance algorithm. In this retrospective, methodologic study, we evaluated the properties of these parameters with regard to test-retest reproducibility and ability to detect a moderate (pharmacologic) and a pronounced (surgical) relief of bladder outlet obstruction. We studied the pressure-flow charts of 42 patients who underwent 24 weeks of androgen suppressive therapy, 42 corresponding patients who received placebo, and 30 patients who had prostate surgery. The patients performed repeat void pressure-flow examinations before and after treatment or placebo. The various parameters were compared. Among the bladder pressure parameters, P(det.Qmax) seemed to have some advantages, supporting the belief that it is the most relevant detrusor pressure parameter to include in nomograms to quantify BOO. In assessment of a large decrease in urethral resistance, such as after TURp, resistance parameters that are based on maximum flow rate as well as detrusor pressure are preferable. PMID:11948710

  13. A comparative study of depot injection techniques.

    PubMed

    Quartermaine, S; Taylor, R

    Depot injections of long-acting neuroleptic drugs, by maintaining a consistent drug regime, together with regular contact with health-care professionals, are an important factor in helping psychiatric patients who live in the community. As these injections are administered over a long period--often for years--it is important that care is taken to minimise discomfort and to reduce the incidence of problems at the injection site. Seepage of even small amounts of the medication will result in an inaccurate dose being absorbed and, owing to the irritant nature of many of these drugs, leakage into subcutaneous tissue and on to the skin surface can cause pain, irritation and lesions. This study was set up to compare two techniques of administering deep intramuscular injections to determine which best fulfilled the criteria of preventing seepage while causing as little discomfort as possible. The two methods used were the Z-track, which is standard practice in the UK, and the air bubble, which is widely taught and used in Canada and the USA. The study showed the air-bubble method to be significantly more effective at controlling seepage than the Z-track. PMID:7644369

  14. Histomorphometric evaluation of intestinal cellular immune responses in pigs immunized with live oral F4ac+ non-enterotoxigenic E. coli vaccine against postweaning colibacillosis

    PubMed Central

    Kovšca Janjatović, A.; Lacković, G.; Božić, F.; Kezić, D.; Popović, M.; Valpotić, H.; Harapin, I.; Pavižić, Ž.; Njari, B.; Valpotić, I.

    2010-01-01

    ileal cell subsets tested were significantly increased (at P<0.5 or lower) in both principal groups (vaccinated or levamisole primed-vaccinated) of pigs, compared to those recorded in the control non-vaccinated pigs. Based on the histomorphometric quantification of porcine intestinal immune cells from the GALT compartments tested, it is possible to differentiate the responses of pigs immunized by an experimental mucosal vaccine from those of non-immunized pigs. PMID:20353911

  15. Periodontal files--a comparative study.

    PubMed

    Pasquini, R; Clark, S M; Baradaran, S; Adams, D F

    1995-12-01

    Periodontal files are used by many dentists for instrumentation of root surfaces as a part of periodontal treatment. The purposes of this study were: 1) to examine, evaluate, and compare several periodontal files in 3 different conditions: new, used, and used/sharpened and 2) to evaluate the efficacy of 5 sharpening devices. The main characteristics observed included: the number, shape, and interval of blades; the active, rake, and lip angles; changes induced by wear; the influence of sharpening; and the type of metal surfaces comprising the blades. There was a wide range of active angles on each individual file, from a high of 75 degrees to a low of 51 degrees. The range of active angles for all blades on all new files was even greater, from a high of 87 degrees to a low of 30 degrees. Wear, observed on some but not all blades, was not extensive and appeared either as abrasion or, occasionally, as fracture of the blade edge. Sharpness scores (5 = sharpest and 1 = dullest) for new file blades were also extremely variable and spanned the full range of values, with a majority of blades scoring 3.5 and below. Attempts to sharpen files with several devices produced inconsistent results. All 5 sharpening devices had significant shortcomings. It was concluded that the extreme ranges both in active angles and in sharpness scores probably have a significant influence on effectiveness of root instrumentation. PMID:8683416

  16. Assays for mammalian tyrosinase: a comparative study

    SciTech Connect

    Jara, J.R.; Solano, F.; Lozano, J.A.

    1988-01-01

    This work describes a comparative study of the tyrosinase activity determined using three methods which are the most extensively employed; two radiometric assays using L-tyrosine as substrate (tyrosine hydroxylase and melanin formation activities) and one spectrophotometric assay using L-dopa (dopa oxidase activity). The three methods were simultaneously employed to measure the activities of the soluble, melanosomal, and microsomal tyrosinase isozymes from Harding-Passey mouse melanoma through their purification processes. The aim of this study was to find any correlation among the tyrosinase activities measured by the three different assays and to determine whether that correlation varied with the isozyme and its degree of purification. The results show that mammalian tyrosinase has a greater turnover number for L-dopa than for L-tyrosine. Thus, enzyme activity, expressed as mumol of substrate transformed per min, is higher in assays using L-dopa as substrate than those using L-tyrosine. Moreover, the percentage of hydroxylated L-tyrosine that is converted into melanin is low and is affected by several factors, apparently decreasing the tyrosinase activity measured by the melanin formation assay. Bearing these considerations in mind, average interassay factors are proposed. Their values are 10 to transform melanin formation into tyrosine hydroxylase activity, 100 to transform tyrosine hydroxylase into dopa oxidase activity, and 1,000 to transform melanin formation into dopa oxidase activity. Variations in these values due to the presence in the tyrosinase preparations of either inhibitors or regulatory factors in melanogenesis independent of tyrosinase are also discussed.

  17. [Histomorphometric analysis of the bones of rats on board the Kosmos 1667 biosatellite].

    PubMed

    Kaplanskiĭ, A S; Durnova, G N; Sakharova, Z F; Il'ina-Kakueva, E I

    1987-01-01

    Bones of the rats flown on Cosmos-1667 were examined histologically and histomorphometrically. It was found that 7-day exposure to weightlessness led to osteoporosis in the spongy matter of proximal metaphyses of tibia and, although to a lesser extent, in the spongiosa of lumbar vertebrae whereas no signs of osteoporosis were seen in the spongy matter of iliac bones. Osteoporosis in the spongy matter of the above bones developed largely due to the inhibition of bone neoformation, which was indicated by a decrease in the number and activity of osteoblasts. Increased bone resorption (as shown by a greater number and activity of osteoclasts) was observed only in the spongy matter of tibial metaphyses. It is emphasized that a reduction of the number of highly active osteoblasts in spongy bones is one of the early signs of inhibition of bone neoformation and development of osteoporosis. PMID:3695333

  18. Comparative Study of Two Automatic Registration Algorithms

    NASA Astrophysics Data System (ADS)

    Grant, D.; Bethel, J.; Crawford, M.

    2013-10-01

    The Iterative Closest Point (ICP) algorithm is prevalent for the automatic fine registration of overlapping pairs of terrestrial laser scanning (TLS) data. This method along with its vast number of variants, obtains the least squares parameters that are necessary to align the TLS data by minimizing some distance metric between the scans. The ICP algorithm uses a "model-data" concept in which the scans obtain differential treatment in the registration process depending on whether they were assigned to be the "model" or "data". For each of the "data" points, corresponding points from the "model" are sought. Another concept of "symmetric correspondence" was proposed in the Point-to-Plane (P2P) algorithm, where both scans are treated equally in the registration process. The P2P method establishes correspondences on both scans and minimizes the point-to-plane distances between the scans by simultaneously considering the stochastic properties of both scans. This paper studies both the ICP and P2P algorithms in terms of their consistency in registration parameters for pairs of TLS data. The question being investigated in this paper is, should scan A be registered to scan B, will the parameters be the same if scan B were registered to scan A? Experiments were conducted with eight pairs of real TLS data which were registered by the two algorithms in the forward (scan A to scan B) and backward (scan B to scan A) modes and the results were compared. The P2P algorithm was found to be more consistent than the ICP algorithm. The differences in registration accuracy between the forward and backward modes were negligible when using the P2P algorithm (mean difference of 0.03 mm). However, the ICP had a mean difference of 4.26 mm. Each scan was also transformed by the forward and backward parameters of the two algorithms and the misclosure computed. The mean misclosure for the P2P algorithm was 0.80 mm while that for the ICP algorithm was 5.39 mm. The conclusion from this study is

  19. The effects of high-fat diet on implant osseointegration: an experimental study

    PubMed Central

    2016-01-01

    Objectives In this study, we investigated whether a high-fat diet (HFD) affected the bone implant connection (BIC) in peri-implant bone. Materials and Methods Four male rabbits were used in this study. Dental implant surgery was introduced into each tibia, and four implants were integrated into each animal. In both the normal diet (ND) group (n=2) and HFD group (n=2), 8 implants were integrated, for a total of 16 integrated implants. The animals continued with their respective diets for 12 weeks post-surgery. Afterward, the rabbits were sacrificed, and the BIC was assessed histomorphometrically. Results Histologic and histomorphometric analyses demonstrated that BIC was not impaired in the HFD group compared to the ND group. Conclusion Within the limitations of this study, we found that HFD did not decrease the BIC in rabbit tibias. PMID:27595085

  20. Histomorphometric Assessment of the Influence of Low-Level Laser Therapy on Peri-Implant Tissue Healing in the Rabbit Mandible

    PubMed Central

    Gomes, Fernando Vacilotto; Mayer, Luciano; de Oliveira, Marília Gerhardt; Baraldi, Carlos Eduardo; Ponzoni, Deise; Puricelli, Edela

    2015-01-01

    Abstract Objective: The purpose of this study was to demonstrate the effect of low-level laser therapy (LLLT) on the peri-implant bone healing process in the rabbit mandible. Background data: LLLT has been shown to accelerate tissue repair and osseointegration of implants placed into the rabbit tibia. However, the beneficial effects of LLLT have never been tested in the rabbit mandible, which would more closely mimic the human situation. Materials and methods: Twenty-four male New Zealand rabbits were randomly divided into four groups of six animals each. All animals had their left mandibular incisors extracted, followed by immediate insertion of a titanium dental implant in the fresh socket. Three groups received LLLT [aluminum-gallium-arsenide (AlGaAs), λ=830nm, 50 mW, continuous wave (CW)] at three different energy densities per treatment session (E-5, 5 J/cm2; E-10, 10 J/cm2; and E-20, 20 J/cm2). Irradiation was performed every 48 h for 13 days, totaling seven sessions. One group received sham treatment (controls). Histological sections were obtained from each of the 24 mandibles dissected, without first decalcifying the specimens, and were stained with hematoxylin and eosin and Picrosirius red for histomorphometric evaluation. Bone-to-implant contact (BIC), bone formation area, and collagen fiber area were assessed by light microscopy. Results: Significant differences were found between group E-20 and all other groups (p<0.05). Histomorphometric evaluation showed significantly higher BIC and significantly more collagen fibers in group E-20. Conclusions: Photobiostimulation with LLLT at an energy density of 20 J/cm2 per session had a significant positive effect on new bone formation around dental implants inserted in the rabbit mandible. PMID:25751666

  1. Flip This Classroom: A Comparative Study

    ERIC Educational Resources Information Center

    Unruh, Tiffany; Peters, Michelle L.; Willis, Jana

    2016-01-01

    The purpose of this research was to compare the beliefs and attitudes of teachers using the flipped versus the traditional class model. Survey and interview data were collected from a matched sample of in-service teachers representing both models from a large suburban southeastern Texas school district. The Attitude Towards Technology Scale, the…

  2. A COMPARATIVE STUDY OF VIDEO TAPE RECORDINGS.

    ERIC Educational Resources Information Center

    WIENS, JACOB H.

    THE COMPARATIVE EFFECTIVENESS OF PRESENTLY AVAILABLE VIDEO TAPE MACHINES IS REPORTED, FOR THE CONVENIENCE OF SCHOOL ADMINISTRATORS PLANNING TO USE SUCH EQUIPMENT IN EDUCATIONAL PROGRAMS. TESTS WERE CONDUCTED AT THE WIENS ELECTRONIC LABORATORIES. MACHINE BRANDS TESTED WERE AMPEX, CONCORD, MACHTRONICS, PRECISION, RCA, SONY, AND WOLLENSAK. A DETAILED…

  3. Counseling in Costa Rica: A Comparative Study

    ERIC Educational Resources Information Center

    Collier, Crystal

    2013-01-01

    With one of the world's most comprehensive universal healthcare systems, medical tourism in Costa Rica has increased significantly over the past few decades. American tourists save up to 80% of comparative costs for procedures, from heart surgery to root canal treatment. Although many Costa Rican healthcare professionals receive training in North…

  4. Histomorphometric, physical, and mechanical effects of spaceflight and insulin-like growth factor-I on rat long bones.

    PubMed

    Bateman, T A; Zimmerman, R J; Ayers, R A; Ferguson, V L; Chapes, S K; Simske, S J

    1998-12-01

    Previous experiments have shown that skeletal unloading resulting from exposure to microgravity induces osteopenia in rats. In maturing rats, this is primarily a function of reduced formation, rather than increased resorption. Insulin-like growth factor-I (IGF-I) stimulates bone formation by increasing collagen synthesis by osteoblasts. The ability of IGF-I to prevent osteopenia otherwise caused by spaceflight was investigated in 12 rats flown for 10 days aboard the Space Shuttle, STS-77. The effect IGF-I had on cortical bone metabolism was generally anabolic. For example, humerus periosteal bone formation increased a significant 37.6% for the spaceflight animals treated with IGF-I, whereas the ground controls increased 24.7%. This increase in humeral bone formation at the periosteum is a result of an increased percent mineralizing perimeter (%Min.Pm), rather than mineral apposition rate (MAR), for both spaceflight and ground control rats. However, IGF-I did inhibit humerus endocortical bone formation in both the spaceflight and ground control rats (38.1% and 39.2%, respectively) by limiting MAR. This effect was verified in a separate ground-based study. Similar histomorphometric results for spaceflight and ground control rats suggest that IGF-I effects occur during normal weight bearing and during spaceflight. Microhardness measurements of the newly formed bone indicate that the quality of the bone formed during IGF-I treatment or spaceflight was not adversely altered. Spaceflight did not consistently change the structural (force-deflection) properties of the femur or humerus when tested in three-point bending. IGF-I significantly increased femoral maximum and fracture strength. PMID:9855461

  5. DELAYED TOOTH REPLANTATION AFTER ROOT SURFACE TREATMENT WITH SODIUM HYPOCHLORITE AND SODIUM FLUORIDE: HISTOMORPHOMETRIC ANALYSIS IN RATS

    PubMed Central

    Sottovia, André Dotto; Sonoda, Celso Koogi; Poi, Wilson Roberto; Panzarini, Sônia Regina; Lauris, José Roberto Pereira

    2006-01-01

    In cases of delayed tooth replantation, non-vital periodontal ligament remnants have been removed with sodium hypochlorite in an attempt to control root resorption. Nevertheless, reports of its irritating potential in contact with the alveolar connective tissue have been described. Therefore, this study evaluated the healing process on delayed replantation of rat teeth, after periodontal ligament removal by different treatment modalities. Twenty-four rats, assigned to 3 groups (n=8), had their upper right incisor extracted and left on the workbench for desiccation during 60 min. Afterwards, the teeth in group I were immersed in saline for 2 min. In group II, root surfaces were scrubbed with gauze soaked in saline for 2 min; and in group III, scrubbing was done with gauze soaked in 1% sodium hypochlorite solution. Thereafter, root surfaces were etched with 37% phosphoric acid and immersed in 2% acidulate-phosphate sodium fluoride solution, at pH 5.5. Root canals were filled with a calcium hydroxide-based paste and the teeth were replanted. The animals were sacrificed 60 days postoperatively and the pieces containing the replanted teeth were processed and paraffin-embedded. Semi-serial transversally sections were obtained from the middle third of the root and stained with hematoxylin and eosin for histomorphometric analysis. Data were analyzed statistically using Kruskal-Wallis and Dunn's tests. The results showed that root structure and cementum extension were more affected by resorption in group III (p<0.05). All groups were affected by root resorption but the treatment performed in group III was the least effective for its control. The treatment accomplished in groups I and II yielded similar results to each other. PMID:19089038

  6. Bacterial contamination control mats: a comparative study.

    PubMed Central

    Meddick, H. M.

    1977-01-01

    The ability of six different types of contamination control mats currently in use at the entrances to theatre suites and other clean areas to remove bacteria-carrying particles from theatre trolley wheeels was compared. Marked differences in the effectiveness of this property were obtained; and all mats showed some disadvantages. Modification of one of the mats has resulted in improved efficiency under working conditions. Images Plate 1 PMID:267665

  7. Comparative transport studies of ``1212'' superconductors

    SciTech Connect

    GAPUD,ALBERT; WU,JUDY; YAN,SHAOLIN; XIE,YI-YUAN; KANG,BYEONGWON; SIEGAL,MICHAEL P.; OVERMYER,DONALD L.

    2000-05-17

    HgBa{sub 2}CaCu{sub 2}O{sub 6+{delta}} (Hg-1212) thin films were fabricated by exchanging the TI cations in TlBa{sub 2}CaCu{sub 2}O{sub 7-{delta}} (Tl-1212) thin films with Hg cations, causing a 30-K increase in Tc. To determine how this exchange effects such a Tc increase, the irreversibility lines, temperature dependence of critical current density, and temperature dependence of Hall angle of Hg-1212 and T1-1212 thin films were measured and then compared. The results strongly suggest that the Tc shift is caused by a doubling of charge carrier density.

  8. Comparative study of some new EPR dosimeters

    NASA Astrophysics Data System (ADS)

    Alzimami, K. S.; Maghraby, Ahmed M.; Bradley, D. A.

    2014-02-01

    Investigations have been made of four new radiation dosimetry EPR candidates from the same family of materials: sulfamic acid, sulfanillic acid, homotaurine, and taurine. Mass energy attenuation coefficients, mass stopping power values and the time dependence of the radiation induced radicals are compared. Also investigated are the microwave saturation behavior and the effect of applied modulation amplitude on both peak-to-peak line width (WPP) and peak-to-peak signal height (HPP). The dosimeters are characterized by simple spectra and stable radiation-induced radicals over reasonable durations, especially in taurine dosimeters. Sulfamic acid dosimeters possessed the highest sensitivity followed by taurine and homotaurine and sulfanillic.

  9. COMPARATIVE STUDIES OF HERPETOMONADS AND LEISHMANIAS

    PubMed Central

    Noguchi, Hideyo; Tilden, Evelyn B.

    1926-01-01

    obtained in culture, all the strains grow well on leptospira medium, as well as on blood slants. Growth takes place both at 26°C. and at 37°. The morphology of the organisms is considerably modified by cultivation. This is especially true of the plant flagellates. In the latex they have ribbon-like bodies, often twisted, and comparatively short flagella; the protoplasm is clear, almost hyaline. The flagellates seen in the gut and feces of insects are usually large, slender organisms, with flagella as long as or even longer than the body, which contains numerous volutin granules in the cytoplasm. In cultures under parallel conditions the flagellates from both these sources become shorter and thicker, the plant forms no longer appear flat and ribbon-like, and in general the organisms approach one another in morphological features. Even in the case of the least modified insect flagellates, i.e. those from flies, there is never exact correspondence between the natural and the cultivated forms. The morphological features of the cultivated flagellates vary according to the medium on which the organisms are grown and the age of the culture. The flagellates grown on the surface of blood slants are pyriform, with truncated anterior portion, and short flagellum; in the condensation water, however, the individuals are elongated and have long active flagella. On the leptospira medium the slender active forms with long flagella predominate. In the presence of fermentable carbohydrate, or in medium containing considerable acid, peculiar bifurcated or multifurcated individuals are seen. Similar forms have been seen under natural conditions. Cultures of Leishmania behave in the same way under the conditions described. There is a striking difference in rapidity of growth between the organisms isolated by us and the leishmanias, H. ctenocephali, and T. rotatorium. While the stock cultures of the group first mentioned multiply rapidly at 37°C., growth becoming visible within 24 hours, the

  10. Comparative study of five blood cardioplegia systems.

    PubMed

    Byrne, C J; Bednarski, A J; Beckley, P D

    1994-12-01

    Five blood cardioplegia delivery systems (Gish Straight Shot, Sorin BCD Advanced, Avecor MYOtherm, Baxter-Bentley HE-30, and Baxter-Bentley HE-30 Gold) were evaluated with respect to ease of rapid priming, coefficient of heat exchange, pressure drop, bubble trap capacity, and priming volume. Each system was placed in a roller pump circuit consisting of source and collection reservoirs, cardioplegia solution, and pre-post system pressure and temperature monitoring sites. A trial was performed on four units of each brand by first priming the circuit with 0.9% NaCl at 200 ml/min. Bovine blood (hematocrit 22%) was then introduced simulating use during bypass. Pressure drops across the heat exchanger were measured at flows of 200, 300, and 400 ml/min and at temperatures of 37 degrees, 19 degrees, and 4 degrees C. Coefficient of heat exchange was determined at 300 ml/min flow. Air was infused into the system to quantify the bubble trap capacity of the heat exchanger module. Priming volume of the entire system and of the heat exchanger module were determined by draining each into a graduated cylinder. The Sorin system had significantly less priming volume when compared to all others. The HE-30 units had significantly higher heat exchange coefficients compared to all other systems. Variability was noted in pressure drop at the highest flows and lowest temperatures. PMID:10150681

  11. A Comparative Study of Compression Video Technology.

    ERIC Educational Resources Information Center

    Keller, Chris A.; And Others

    The purpose of this study was to provide an overview of compression devices used to increase the cost effectiveness of teleconferences by reducing satellite bandwidth requirements for the transmission of television pictures and accompanying audio signals. The main body of the report describes the comparison study of compression rates and their…

  12. Comparative results of 327 chemical carcinogenicity studies.

    PubMed Central

    Haseman, J K; Huff, J E; Zeiger, E; McConnell, E E

    1987-01-01

    The National Cancer Institute (NCI) and the National Toxicology Program (NTP) have carried out a number of laboratory animal carcinogenicity studies and presented the results of these experiments in a series of Technical Reports. This paper tabulates the results of the 327 NCI/NTP studies carried out to date on 308 distinct chemicals, and discusses certain issues relevant to the evaluation of carcinogenicity in these experiments. This compilation of results from NCI/NTP carcinogenicity experiments provides a large database that can be used to study structure-activity correlations, interspecies concordance, and associations between laboratory animal carcinogenicity and other toxicological effects. PMID:3691430

  13. A Comparative Study of Landmine Detection Techniques

    NASA Astrophysics Data System (ADS)

    Kasban, H.; Zahran, O.; Elaraby, Sayed M.; El-Kordy, M.; Abd El-Samie, F. E.

    2010-09-01

    Several countries suffer from the existence of millions of buried landmines in their territories. These landmines have indefinite life, and may still cause horrific personal injuries and economic dislocation for decades after a war has finished. Therefore, there is a growing demand by these countries for reliable landmine inspection systems. There are several landmine detection techniques that can be used for this purpose. Each technique is suitable for detection under some conditions depending on the type of the landmine case, the explosive material, and the soil. This paper presents an overview of some of the existing landmine detection techniques. These techniques are briefly described and their merits and drawbacks are highlighted and compared. The purpose of this comparison is to shows the ideal conditions and the challenges for each technique. Furthermore, a comparison between landmine detection techniques from the points of view of cost, complexity, speed, safety, false alarm rate and effect of environmental conditions is presented.

  14. Histomorphometric Assessment of Cancellous and Cortical Bone Material Distribution in the Proximal Humerus of Normal and Osteoporotic Individuals: Significantly Reduced Bone Stock in the Metaphyseal and Subcapital Regions of Osteoporotic Individuals.

    PubMed

    Sprecher, Christoph M; Schmidutz, Florian; Helfen, Tobias; Richards, R Geoff; Blauth, Michael; Milz, Stefan

    2015-12-01

    Osteoporosis is a systemic disorder predominantly affecting postmenopausal women but also men at an advanced age. Both genders may suffer from low-energy fractures of, for example, the proximal humerus when reduction of the bone stock or/and quality has occurred.The aim of the current study was to compare the amount of bone in typical fracture zones of the proximal humerus in osteoporotic and non-osteoporotic individuals.The amount of bone in the proximal humerus was determined histomorphometrically in frontal plane sections. The donor bones were allocated to normal and osteoporotic groups using the T-score from distal radius DXA measurements of the same extremities. The T-score evaluation was done according to WHO criteria. Regional thickness of the subchondral plate and the metaphyseal cortical bone were measured using interactive image analysis.At all measured locations the amount of cancellous bone was significantly lower in individuals from the osteoporotic group compared to the non-osteoporotic one. The osteoporotic group showed more significant differences between regions of the same bone than the non-osteoporotic group. In both groups the subchondral cancellous bone and the subchondral plate were least affected by bone loss. In contrast, the medial metaphyseal region in the osteoporotic group exhibited higher bone loss in comparison to the lateral side.This observation may explain prevailing fracture patterns, which frequently involve compression fractures and certainly has an influence on the stability of implants placed in this medial region. It should be considered when planning the anchoring of osteosynthesis materials in osteoporotic patients with fractures of the proximal humerus. PMID:26705200

  15. Comparative study of skew detection algorithms

    NASA Astrophysics Data System (ADS)

    Amin, Adnan; Fischer, Stephen; Parkinson, Anthony F.; Shiu, Ricky

    1996-10-01

    Document image processing has become an increasingly important technology in the automation of office documentation tasks. Automatic document scanners such as text readers and optical character recognition systems are an essential component of systems capable of those tasks. One of the problems in this field is that the document to be read is not always placed correctly on a flat-bed scanner. This means that the document may be skewed on the scanner bed, resulting in a skewed image. This skew has a detrimental effect on document analysis, document understanding, and character segmentation and recognition. Consequently, detecting the skew of a document image and correcting it are important issues in realizing a practical document reader. We describe a new algorithm for skew detection. We then compare the performance and results of this skew detection algorithm to other published methods from O'Gorman, Hinds, Le, Baird, Postl, and Akiyama. Finally, we discuss the theory of skew detection and the different approaches taken to solve the problem of skew in documents. The skew correction algorithm we propose has been shown to be extremely fast, with run times averaging under 0.25 CPU seconds to calculate the angle on a DEC 5000/20 workstation.

  16. Toucan and hornbill beaks: a comparative study.

    PubMed

    Seki, Yasuaki; Bodde, Sara G; Meyers, Marc A

    2010-02-01

    The structure and mechanical behavior of Toco Toucan (Ramphastos toco) and Wreathed Hornbill (Rhyticeros undulatus) beaks were compared. The beak of both species is a sandwich-structured composite, having an exterior, or rhamphotheca, consisting of multiple layers of keratin scales and a core composed of a fibrous network of bony closed-cell foam. The rhamphotheca is an arrangement of approximately 50microm diameter, overlapping, keratin tiles. The hornbill rhamphotheca exhibits a surface morphology on the ridged casque that is distinguishable from that observed on the bill proper. Intermediate filaments in the keratin matrix were observed by transmission electron microscopy. The Young's modulus measurements of toucan rhamphotheca indicate isotropy in longitudinal and transverse directions, whereas those of hornbill rhamphotheca may suggest anisotropy. The compressive response of beak foam is governed by brittle crushing behavior. The crushing strength of hornbill foam is six times higher than that of toucan foam. Micro- and nanoindentation hardness values were measured for rhamphotheca and foam trabeculae of toucan and hornbill specimens. The sandwich design of beaks was analyzed using the Karam-Gibson and Dawson-Gibson models. The presence of a cellular core increases the bending resistance (Brazier moment) by a factor of 3-6 while decreasing the compressive strength by only 50%. PMID:19699818

  17. LES versus DNS: A comparative study

    NASA Technical Reports Server (NTRS)

    Shtilman, L.; Chasnov, J. R.

    1992-01-01

    We have performed Direct Numerical Simulations (DNS) and Large Eddy Simulations (LES) of forced isotropic turbulence at moderate Reynolds numbers. The subgrid scale model used in the LES is based on an eddy viscosity which adjusts instantaneously the energy spectrum of the LES to that of the DNS. The statistics of the large scales of the DNS (filtered DNS field or fDNS) are compared to that of the LES. We present results for the transfer spectra, the skewness and flatness factors of the velocity components, the PDF's of the angle between the vorticity and the eigenvectors of the rate of strain, and that between the vorticity and the vorticity stretching tensor. The above LES statistics are found to be in good agreement with those measured in the fDNS field. We further observe that in all the numerical measurements, the trend was for the LES field to be more gaussian than the fDNS field. Future research on this point is planned.

  18. Children's Friendship Development: A Comparative Study

    ERIC Educational Resources Information Center

    Yu, SeonYeong; Ostrosky, Michaelene M.; Fowler, Susan A.

    2011-01-01

    Establishing friendships is an important developmental goal of early childhood, but little research has addressed ways in which parents support the friendship development of their young children with disabilities. The purpose of this survey study was to explore the support strategies that parents use to facilitate their children's friendships.…

  19. Social Studies. Language Arts: Comparative World Religions.

    ERIC Educational Resources Information Center

    Moore, John A.

    The elective (7-9) course in world religions outlined in this guide is designed to fit the quinmester organization of schools. The course is described as a study of world religions, focusing on religion as an institution in society. It includes effects of religion on people, governments, and internal relations. The guide is divided according to:…

  20. Articulation of Quality Teaching: A Comparative Study

    ERIC Educational Resources Information Center

    Sakarneh, Mohammad

    2015-01-01

    The aim of this study is to describe and then contrast the New South Wales Department of Education and Training's model of quality teaching with the Jordanian Ministry of Education's conception of quality teaching, looking particularly at potential differences in interpretation. A content analysis methodology was used. Each perspective has been…

  1. Metacognition and Group Differences: A Comparative Study

    ERIC Educational Resources Information Center

    Al-Hilawani, Yasser A.

    2014-01-01

    In this study, metacognition refers to performing visual analysis and discrimination of real life events and situations in naïve psychology, naïve physics, and naïve biology domains. It is used, along with measuring reaction time, to examine differences in the ability of four groups of students to select appropriate pictures that correspond with…

  2. Implicature, Pragmatics, and Documentation: A Comparative Study

    ERIC Educational Resources Information Center

    Wright, David

    2008-01-01

    This study investigates the link between the linguistic principles of implicature and pragmatics and software documentation. When implicatures are created in conversation or text, the listener or reader is required to fill in missing information not overtly stated. This information is usually filled in on the basis of previous knowledge or…

  3. Earthquake correlations and networks: A comparative study

    SciTech Connect

    Krishna Mohan, T. R.; Revathi, P. G.

    2011-04-15

    We quantify the correlation between earthquakes and use the same to extract causally connected earthquake pairs. Our correlation metric is a variation on the one introduced by Baiesi and Paczuski [M. Baiesi and M. Paczuski, Phys. Rev. E 69, 066106 (2004)]. A network of earthquakes is then constructed from the time-ordered catalog and with links between the more correlated ones. A list of recurrences to each of the earthquakes is identified employing correlation thresholds to demarcate the most meaningful ones in each cluster. Data pertaining to three different seismic regions (viz., California, Japan, and the Himalayas) are comparatively analyzed using such a network model. The distribution of recurrence lengths and recurrence times are two of the key features analyzed to draw conclusions about the universal aspects of such a network model. We find that the unimodal feature of recurrence length distribution, which helps to associate typical rupture lengths with different magnitude earthquakes, is robust across the different seismic regions. The out-degree of the networks shows a hub structure rooted on the large magnitude earthquakes. In-degree distribution is seen to be dependent on the density of events in the neighborhood. Power laws, with two regimes having different exponents, are obtained with recurrence time distribution. The first regime confirms the Omori law for aftershocks while the second regime, with a faster falloff for the larger recurrence times, establishes that pure spatial recurrences also follow a power-law distribution. The crossover to the second power-law regime can be taken to be signaling the end of the aftershock regime in an objective fashion.

  4. Comparative Study of Morphometric and Fourier Transform Infrared Spectroscopy Analyses of the Collagen Fibers in the Repair Process of Cutaneous Lesions

    PubMed Central

    Nogueira, Veruska Cronemberger; Raniero, Leandro; Costa, Guilherme Bueno; de Freitas Coelho, Nayana Pinheiro Machado; Miranda, Fernando Cronemberger; Arisawa, Emília Ângela Loschiavo

    2016-01-01

    Objective: Compare the efficacy of light-emitting diode (LED) and therapeutic ultrasound (TUS), combined with a semipermeable dressing (D), at forming collagen in skin lesions by morphometry and Fourier transform infrared spectroscopy (FT-IR). Materials and Methods: Surgical skin wounds (2.5 cm) were created on 84 male Wistar rats divided into four groups (n=21): Group I (Control), Group II (LED), Group III (LED+D), and Group IV (US+D). On days 7, 14, and 21, the tissue samples were removed and divided into two pieces, one was used for histological examination (collagen) and the other for FT-IR. Results: The histomorphometric analysis showed no significant differences among groups for collagen deposition at 7 days. However, at 14 days, more deposition of collagen was noted in the groups LED (p<0.05) and LED+D (p<0.001) than in the control. At 21 days, the groups LED, LED+D, and US+D presented significantly greater deposition of collagen when compared with the control. The FT-IR spectra, at 14 days, LED+D had greater amounts of type I collagen, a better organization of fibers, and greater difference of mean separation between the groups, not observed at 7 and 21 days. Innovation: The histomorphometric and FT-IR analyses suggest that the association of semipermeable dressing to LED therapy and to TUS modulates biological events, increasing fibroblast/collagen response and accelerating dermal maturation. Conclusion: The histomorphometric and FT-IR analyses showed that LED therapy is more efficacious than TUS, when combined with a semipermeable dressing, and induced the collagen production in skin lesions. PMID:26862463

  5. Comparative study of the 2016 DPRK event

    NASA Astrophysics Data System (ADS)

    Kebede, Fekadu; Jonathan, Ezekiel; Graham, Gerhard

    2016-04-01

    Effective monitoring of any violations of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) depends upon the State Parties' ability to determine the nature of the source of the signals recorded by the IMS stations. Analysis by the IDC of the data gives some of the required information but makes no effort to determine the nature of source as specified by the Treaty. On January 6, 2016 the IMS network of stations recorded unusual seismic event from the DPRK. This was the fourth time that such an event from a man-made event was recorded from this area. Past detections of announced nuclear tests were on 9 October 2006, 25 May 2009, and 12 February 2013. There are a few natural earthquakes that have been recorded in this region. This study presents results of an assessment of waveform data and amplitude spectra obtained from seismic events observed at regional and/or local distance ranges, for both natural and man-made events located in the DPRK. The study reveals that the waveform displays of the four man-made events are practically simple and have nearly the same signature, yet they are significantly different to those of the observed natural earthquakes occurring in the region. The similarities of the waveforms obtained from the man-made events are due to the closeness of the epicentres and hence no difference in path effects for the Stations considered. The computed amplitude spectra of the waveform for the man-made and natural events also show differences in their relative amplitudes between the respective Primary and Secondary seismic phases, indicating that their sources are different. The study clearly shows the importance of studying the signature of the recorded seismic waves to determine the nature of the source of the energy, if it is man-made or natural, particularly for regions where records of natural earthquakes exist. Determination of the nature of source of recorded seismic waves is fundamental to CTBT verification. Thus data observed at regional and

  6. Egress of Alphaherpesviruses: Comparative Ultrastructural Study

    PubMed Central

    Granzow, Harald; Klupp, Barbara G.; Fuchs, Walter; Veits, Jutta; Osterrieder, Nikolaus; Mettenleiter, Thomas C.

    2001-01-01

    Egress of four important alphaherpesviruses, equine herpesvirus 1 (EHV-1), herpes simplex virus type 1 (HSV-1), infectious laryngotracheitis virus (ILTV), and pseudorabies virus (PrV), was investigated by electron microscopy of infected cell lines of different origins. In all virus-cell systems analyzed, similar observations were made concerning the different stages of virion morphogenesis. After intranuclear assembly, nucleocapsids bud at the inner leaflet of the nuclear membrane, resulting in enveloped particles in the perinuclear space that contain a sharply bordered rim of tegument and a smooth envelope surface. Egress from the perinuclear cisterna primarily occurs by fusion of the primary envelope with the outer leaflet of the nuclear membrane, which has been visualized for HSV-1 and EHV-1 for the first time. The resulting intracytoplasmic naked nucleocapsids are enveloped at membranes of the trans-Golgi network (TGN), as shown by immunogold labeling with a TGN-specific antiserum. Virions containing their final envelope differ in morphology from particles within the perinuclear cisterna by visible surface projections and a diffuse tegument. Particularly striking was the addition of a large amount of tegument material to ILTV capsids in the cytoplasm. Extracellular virions were morphologically identical to virions within Golgi-derived vesicles, but distinct from virions in the perinuclear space. Studies with gB- and gH-deleted PrV mutants indicated that these two glycoproteins, which are essential for virus entry and direct cell-to-cell spread, are dispensable for egress. Taken together, our studies indicate that the deenvelopment-reenvelopment process of herpesvirus maturation also occurs in EHV-1, HSV-1, and ILTV and that membrane fusion processes occurring during egress are substantially different from those during entry and direct viral cell-to-cell spread. PMID:11264357

  7. A comparative study of AGN feedback algorithms

    NASA Astrophysics Data System (ADS)

    Wurster, J.; Thacker, R. J.

    2013-05-01

    Modelling active galactic nuclei (AGN) feedback in numerical simulations is both technically and theoretically challenging, with numerous approaches having been published in the literature. We present a study of five distinct approaches to modelling AGN feedback within gravitohydrodynamic simulations of major mergers of Milky Way-sized galaxies. To constrain differences to only be between AGN feedback models, all simulations start from the same initial conditions and use the same star formation algorithm. Most AGN feedback algorithms have five key aspects: the black hole accretion rate, energy feedback rate and method, particle accretion algorithm, black hole advection algorithm and black hole merger algorithm. All models follow different accretion histories, and in some cases, accretion rates differ by up to three orders of magnitude at any given time. We consider models with either thermal or kinetic feedback, with the associated energy deposited locally around the black hole. Each feedback algorithm modifies the region around the black hole to different extents, yielding gas densities and temperatures within r ˜ 200 pc that differ by up to six orders of magnitude at any given time. The particle accretion algorithms usually maintain good agreement between the total mass accreted by dot{M} dt and the total mass of gas particles removed from the simulation, although not all algorithms guarantee this to be true. The black hole advection algorithms dampen inappropriate dragging of the black holes by two-body interactions. Advecting the black hole a limited distance based upon local mass distributions has many desirably properties, such as avoiding large artificial jumps and allowing the possibility of the black hole remaining in a gas void. Lastly, two black holes instantly merge when given criteria are met, and we find a range of merger times for different criteria. This is important since the AGN feedback rate changes across the merger in a way that is dependent

  8. Comparative mirror cleaning study: a study on removing particulate contamination

    NASA Astrophysics Data System (ADS)

    Houston, Karrie D.

    2006-08-01

    A mirror cleaning study was conducted to assess the effectiveness of three cleaning methods in their ability to remove particulate contamination from reflective mirror surfaces. Presently, the detergent bath, solvent rinse, and CO II snow cleaning methods are the most commonly used optical cleaning techniques within the optics industry. These techniques are also commonly used by the Optics Branch/Code 551 at Goddard Space Flight Center (GSFC) to remove particulate contamination from optical surfaces. In this experimental study, the above-mentioned cleaning methods were used to clean twelve uncoated silicon wafers, twelve gold coated silicon wafers, and twelve gold coated silicon wafers with a silicon oxide protective coating. CO II snow cleaning had an average removal percentage of 84%, followed by the solvent rinse at 74%, and the detergent bath at 61%. In addition to the average removal percentage, this comparative study was designed to: (1) determine the cleaning ability of each method based on the number and size of removed particles; (2) assess the risk of surface damage for each cleaning procedure; (3) evaluate each cleaning method as a function of its initial "qualitative" contamination level ("fairly clean", "dirty", and "very dirty"). The particulate cleanliness of all wafers was characterized using Image Analysis and Image-Pro Plus 5.0 software. In addition, the experimental design and experimental results were analyzed using JMP/Statistical Analytical Software Version 6.0.

  9. A comparative study of the bone metabolic response to dried plum supplementation and PTH treatment in adult, osteopenic ovariectomized rat.

    PubMed

    Smith, Brenda J; Bu, So Young; Wang, Yan; Rendina, Elizabeth; Lim, Yin F; Marlow, Denver; Clarke, Stephen L; Cullen, Diane M; Lucas, Edralin A

    2014-01-01

    Dried plum has been reported to have potent effects on bone in osteopenic animal models, but the mechanisms through which bone metabolism is altered in vivo remain unclear. To address this issue, a study comparing the metabolic response of dried plum to the anabolic agent, parathyroid hormone (PTH), was undertaken. Six month-old female Sprague Dawley rats (n=84) were sham-operated (SHAM) or ovariectomized (OVX) and maintained on a control diet for 6wks until osteopenia was confirmed. Treatments were initiated consisting of a control diet (AIN-93M) supplemented with dried plum (0, 5, 15 or 25%; w/w) or a positive control group receiving PTH. At the end of 6wks of treatment, whole body and femoral bone mineral density (BMD) were restored by the two higher doses of dried plum to the level of the SHAM group. Trabecular bone volume and cortical thickness were also improved with these two doses of dried plum. Dried plum suppressed the OVX-induced increase in bone turnover as indicated by systemic biomarkers of bone metabolism, N-terminal procollagen type 1 (P1NP) and deoxypyridinoline (DPD). Dynamic bone histomorphometric analysis of the tibial metaphysis revealed that dried plum restored the OVX-induced increase in cancellous bone formation rate (BFR) and mineralizing surface (MS/BS) to the SHAM group, but some doses of dried plum increased endocortical mineral apposition rate (MAR). As expected, PTH significantly increased endocortical MAR and BFR, periosteal BFR, and trabecular MAR and BFR beyond that of the OVX and maintained the accelerated rate of bone resorption associated with OVX. Dried plum up-regulated bone morphogenetic protein 4 (Bmp4) and insulin-like growth factor 1 (Igf1) while down-regulating nuclear factor T cell activator 1 (Nfatc1). These findings demonstrate that in the adult osteopenic OVX animal, the effects of dried plum differ from that of PTH in that dried plum primarily suppressed bone turnover with the exception of the indices of bone

  10. Histopathological, histomorphometrical, and immunohistochemical biomarkers in flounder (Platichthys flesus) from the southern Baltic Sea.

    PubMed

    Dabrowska, Henryka; Ostaszewska, Teresa; Kamaszewski, Maciej; Antoniak, Agnieszka; Napora-Rutkowski, Lukasz; Kopko, Orest; Lang, Thomas; Fricke, Nicolai F; Lehtonen, Kari K

    2012-04-01

    Flounder (Platichthys flesus), collected in late fall of 2009 from four coastal sites in the southern Baltic Sea including the Gulf of Gdańsk (GoG), were investigated for a suite of biomarkers of contaminant effects. The biomarkers included liver histopathologies, which were diagnosed and assessed using commonly applied lesion categories, the size and density of melano-macrophage aggregates (MMAs), expression of proliferating cell nuclear antigen (PCNA) and of cytochrome P450 1A (CYP1A) in liver as well as the size and density of MMAs and density of Perls'-positive cells in the spleen. The prevalence of liver lesions differed among the sites. Most frequently occurring were non-specific and early toxicopathic non-neoplastic lesions. Mean MMA size was in the range of 264-519 μm(2) and 717-2137 μm(2) in liver and spleen, respectively, and density was in the range of 6-13 and 15-26 MMAmm(-2), respectively. Mean density of PCNA-positive hepatocytes was in the range of 300-1281 cellsmm(-2). These histomorphometrical biomarkers correlated positively with the muscle Hg, Σ(7)PCB, and ΣDDT residues and negatively with the indices of general liver condition. They showed significant differences between the sites, which were in line with the spatial prevalence of liver lesions and CYP1A induction. Overall, the biomarker responses were more pronounced in the GoG sites in comparison to those outside the Gulf, which confirms some earlier results and broadens the knowledge of contaminant effects in the Polish coastal zone of the Baltic Sea. PMID:22118815

  11. What Do We Compare When We Compare Religions? Philosophical Remarks on the Psychology of Studying Comparative Religion Abroad

    ERIC Educational Resources Information Center

    Irvine, Andrew

    2015-01-01

    The issue of comparison is a vexing one in religious and theological studies, not least for teachers of comparative religion in study abroad settings. We try to make familiar ideas fresh and strange, in settings where students may find it hard not to take "fresh" and "strange" as signs of existential threat. The author explores…

  12. Analysis of new bone, cartilage, and fibrosis tissue in healing murine allografts using whole slide imaging and a new automated histomorphometric algorithm

    PubMed Central

    Zhang, Longze; Chang, Martin; Beck, Christopher A; Schwarz, Edward M; Boyce, Brendan F

    2016-01-01

    Histomorphometric analysis of histologic sections of normal and diseased bone samples, such as healing allografts and fractures, is widely used in bone research. However, the utility of traditional semi-automated methods is limited because they are labor-intensive and can have high interobserver variability depending upon the parameters being assessed, and primary data cannot be re-analyzed automatically. Automated histomorphometry has long been recognized as a solution for these issues, and recently has become more feasible with the development of digital whole slide imaging and computerized image analysis systems that can interact with digital slides. Here, we describe the development and validation of an automated application (algorithm) using Visiopharm’s image analysis system to quantify newly formed bone, cartilage, and fibrous tissue in healing murine femoral allografts in high-quality digital images of H&E/alcian blue-stained decalcified histologic sections. To validate this algorithm, we compared the results obtained independently using OsteoMeasureTM and Visiopharm image analysis systems. The intraclass correlation coefficient between Visiopharm and OsteoMeasure was very close to one for all tissue elements tested, indicating nearly perfect reproducibility across methods. This new algorithm represents an accurate and labor-efficient method to quantify bone, cartilage, and fibrous tissue in healing mouse allografts. PMID:26816658

  13. Technology-Enhanced Consultation in Counselling: A Comparative Study

    ERIC Educational Resources Information Center

    Astramovich, Randall L.; Jones, W. Paul; Coker, J. Kelly

    2004-01-01

    Two quasi-experimental studies comparing technology-enhanced counselling consultation were conducted with a sample of 147 students enrolled in an undergraduate counselling and consultation course for elementary and secondary teachers. Study 1 (N = 76) compared the effectiveness of counselling consultation using telephone, text chat, or text chat…

  14. The Illiteracy Myth. A Comparative Study of Prisoner Literacy Abilities.

    ERIC Educational Resources Information Center

    Black, Stephen; And Others

    Illiteracy is seen to be a feature of the Australian prisoner population. This belief has remained largely untested. A study compared the literacy abilities of prisoners to those found in the adult general population. Additionally, the study compared male and female prisoner literacy abilities. Assessments were made on a profile of literacy…

  15. [Studies of Student Performance on the Comparative Guidance Placement Program.

    ERIC Educational Resources Information Center

    Reed, M. Douglas

    Data from the College Entrance Examination Board's Comparative Guidance and Placement (CGP) Program were used in these two studies of students at Central Virginia Community College (CVCC). In the first study, 1971 fall quarter performance in specific courses and in all courses was compared to CGP performance. The conclusions indicate that: (1) CGP…

  16. Teacher Training and Multiculturalism: National Studies. Studies in Comparative Education.

    ERIC Educational Resources Information Center

    Gagliardi, Raul, Ed.

    This book presents outcomes of UNESCO (United Nations Educational, Scientific, and Cultural Organization) studies on teacher training in eight countries (Bolivia, the Czech Republic, Jordan, Lebanon, Mauritius, Poland, Senegal, and Tunisia) representing different levels of development and different regions of the world but who are facing a common…

  17. From Comparative Education to Comparative Pedagogy: A Physical Education Case Study

    ERIC Educational Resources Information Center

    Georgakis, Steve; Graham, Jessica

    2016-01-01

    In the last two decades forces of globalization and the rise of and access to information technology have transformed the nature of educational research. Traditional disciplines such as comparative education have not been immune to these transformational impacts. Although one might expect globalization to promote the study of comparative…

  18. Nephrotoxic effect of tetradifon in rats: a biochemical and histomorphometric study.

    PubMed

    Badraoui, Riadh; Ben Nasr, Hmed; Louati, Rim; Ellouze, Feriel; Rebai, Tarek

    2012-09-01

    The effects of subchronic exposure to tetradifon on biochemical related kidney toxicological parameters [creatinine (CRT), urea, and uric acid (UA)] were examined. Oxidative stress in kidney tissue was also assessed by measuring vitamin C (VitC) content and antioxidant enzyme activities [superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)]. Tetradifon was administered orally to 12 rats at a cumulative dose of 24.3 mg/kg for 12 weeks. Twelve additional rats, no treated, have served as control. Control and treated animals were sacrificed after 6 or 12 weeks. For each group, kidneys were examined for morphometric changes. Results showed that tetradifon induced significant increases in CRT and urea, and decrease in UA. Morphometrically, while mean glomerular volume decreased percentage of sclerosed glomeruli increased in treated rats. Index of interstitial fibrosis was significantly higher. Moreover, renal antioxidant enzyme (SOD and GPx) activities and VitC content decreased. We concluded that tetradifon possessed nephrotoxic by promoting kidney morphometric and functional damage and depleting renal antioxidant defense system in rats. PMID:21216578

  19. A Comparative Study of Document Retrieval Systems of Nursing Interest.

    ERIC Educational Resources Information Center

    Saba, Virginia Kathleen Joseph

    Intended to provide the nursing community with a comparative analysis of four major computerized document retrieval systems and one manual system providing coverage of the nursing literature, this study compares the indexing vocabulary, database coverage, and retrieval performance of the Educational Resource Information Center (ERIC),…

  20. A Comparative Study of Croatian and Hungarian EFL Students

    ERIC Educational Resources Information Center

    Mihaljevic Djigunovic, Jelena; Nikolov, Marianne; Otto, Istvan

    2008-01-01

    This comparative research aims to provide insights into how Croatian and Hungarian 8th graders' proficiency in English as a foreign language (EFL) compares to one another in relation to organizational macro factors. A total of 717 14-year-old students participated in the study in two neighboring regions and towns of Croatia and Hungary examining…

  1. Mobile Learning vs. Traditional Classroom Lessons: A Comparative Study

    ERIC Educational Resources Information Center

    Furió, D.; Juan, M.-C.; Seguí, I.; Vivó, R.

    2015-01-01

    Different methods can be used for learning, and they can be compared in several aspects, especially those related to learning outcomes. In this paper, we present a study in order to compare the learning effectiveness and satisfaction of children using an iPhone game for learning the water cycle vs. the traditional classroom lesson. The iPhone game…

  2. Assistance to Libraries in Developing Nations: Papers on Comparative Studies.

    ERIC Educational Resources Information Center

    Williamson, William L., Ed.

    The papers presented at a one day workshop on the aspects of comparative librarianship are presented in this volume. The topics discussed are: (1) Methods and Evidence in Comparative Studies; (2) Social Change and Library Development; (3) Library Development in Latin America, a Scalogram; (4) Cross-Cultural Aspects of Assistance to Developing…

  3. [Comparative study on nutmeg, mace and their processed products].

    PubMed

    Jia, T; Wang, Z; Wang, Y; Li, J

    1997-09-01

    The contents of volatile oil, myristicin, safrol and methyleugenol, as well as the composition and content of fatty oil in nutmeg, mace and their processed products were comparatively studied. The composition of volatile oil and the detection of trimyristin were compared by TLC. A scientific basis for the development and application of mace has thus been provided. PMID:11038942

  4. Comparative Studies in Adult Education--A Review.

    ERIC Educational Resources Information Center

    Charters, Alexander N.

    One of the most important recent developments in comparative adult education (CAE) has been the formation in 1987 of the Committee for Study and Research in Comparative Adult Education (CSRCAE), jointly founded by the International Council of Adult Education and the International Congress of University Adult Education. The Committee continues to…

  5. Comparative Mirror Cleaning Study: 'A Study on Removing Particulate Contamination'

    NASA Technical Reports Server (NTRS)

    Houston, Karrie

    2007-01-01

    The cleanliness of optical surfaces is recognized as an industry-wide concern for the performance of optical devices such as mirrors and telescopes, microscopes and lenses, lasers and interferometers, and prisms and optical filters. However, no standard has been established for optical cleaning and there is no standard definition of a 'clean' optical element. This study evaluates the effectiveness of commonly used optical cleaning techniques based on wafer configuration, contamination levels, and the number and size of removed particles. It is concluded that cleaning method and exposure time play a significant factor in obtaining a high removal percentage. The detergent bath and solvent rinse method displayed an increase in effective removal percentage as the contamination exposure increased. Likewise, CO2 snow cleaning showed a relatively consistent cleaning effectiveness. The results can help ensure mission success to flight projects developed for the NASA Origins Program. Advantages and disadvantages of each of the optical cleaning methods are described.

  6. Religious Confession and Symptom Severity: A Prospective Comparative Study.

    PubMed

    Rana, Madiha; Rana, Majeed; Herzberg, Philipp Y; Krause, Christin

    2015-12-01

    Little research has been done on comparing confessions regarding mental health. In the present study, 320 people (78 Buddhists, 77 Catholics, 89 Protestants and 79 Muslims) were compared in terms of their symptom severity. Buddhists and Protestants had lower scores than Catholics and Muslims for obsessive-compulsive behavior and hostility. Muslim group had the highest comparative scores for psychoticism. Buddhists and Protestants had comparatively low scores for paranoid ideation and overall symptom severity, with Catholics and Muslims having high ones. Results reveal that confession should be taken in account in psychological research and diagnosis, since it is explicitly associated with psychological well-being. PMID:25204789

  7. Teacher Leader Human Relations Skills: A Comparative Study

    ERIC Educational Resources Information Center

    Roby, Douglas E.

    2012-01-01

    In this study, 142 graduate school teachers working in schools throughout southwestern Ohio assessed their human relation skills. A human relations survey was used for the study, and results were compared with colleagues assessing the teachers in the study. The survey was developed using a Likert-type scale, and was based on key elements affecting…

  8. Histomorphometric characteristics of immune cells in small intestine of pigs perorally immunized with vaccine candidate F18ac+ nonenterotoxigenic E. coli strain

    PubMed Central

    Kovšca Janjatović, A.; Lacković, G.; Božić, F.; Špoljarić, D.; Popović, M.; Valpotić, H.; Vijtiuk, N.; Pavičić, Ž.; Valpotić, I.

    2009-01-01

    Colidiarrhea and colienterotoxemia caused by F4+ and/or F18+ enterotoxigenic E. coli (ETEC) strains are the most prevalent infections of suckling and weaned pigs. Here we tested the immunogenicity and protective effectiveness of attenuated F18ac+ non-ETEC vaccine candidate strain against challenge infection with F4ac+ ETEC strain by quantitative phenotypic analysis of small intestinal leukocyte subsets in weaned pigs.We also evaluated levamisole as an immune response modifier (IRM) and its adjuvanticity when given in the combination with the experimental vaccine. The pigs were parenterally immunized with either levamisole (at days -2, -1 and 0) or with levamisole and perorally given F18ac+ non-ETEC strain (at day 0), and challenged with F4ac+ ETEC strain 7 days later.At day 13 the pigs were euthanatized and sampled for immunohistological/histomorphometrical analyses. Lymphoid CD3+, CD45RA+, CD45RC+, CD21+, IgA+ and myeloid SWC3+ cell subsets were identified in jejunal and ileal epithelium, lamina propria and Peyer’s patches using the avidin-biotin complex method, and their numbers were determined by computer-assisted histomorphometry. Quantitative immunophenotypic analyses showed that levamisole treated pigs had highly increased numbers of jejunal CD3+, CD45RC+ and SWC3+ cells (p<0.05) as compared to those recorded in nontreated control pigs.In the ileum of these pigs we have recorded that only CD21+ cells were significantly increased (p<0.01). The pigs that were treated with levamisole adjuvanted experimental vaccine had significantly increased numbers of all tested cell subsets in both segments of the small intestine. It was concluded that levamisole adjuvanted F18ac+ non-ETEC vaccine was a requirement for the elicitation of protective gut immunity in this model; nonspecific immunization with levamisole was less effective, but confirmed its potential as an IRM. PMID:22073355

  9. Comparative Study of Bio-implantable Acoustic Generator Architectures

    NASA Astrophysics Data System (ADS)

    Christensen, D.; Roundy, S.

    2013-12-01

    This paper is a comparative study of the design spaces of two bio-implantable acoustically excited generator architectures: the thickness-stretch-mode circular piezoelectric plate and the bending-mode unimorph piezoelectric diaphragm. The generators are part of an acoustic power transfer system for implanted sensors and medical devices such as glucose monitors, metabolic monitors, drug delivery systems, etc. Our studies indicate that at small sizes the diaphragm architecture outperforms the plate architecture. This paper will present the results of simulation studies and initial experiments that explore the characteristics of the two architectures and compare their performance.

  10. Sustainability of Social Programs: A Comparative Case Study Analysis

    ERIC Educational Resources Information Center

    Savaya, Riki; Spiro, Shimon; Elran-Barak, Roni

    2008-01-01

    The article reports on the findings of a comparative case study of six projects that operated in Israel between 1980 and 2000. The study findings identify characteristics of the programs, the host organizations, and the social and political environment, which differentiated programs that are sustained from those that are not. The findings reaffirm…

  11. Entrepreneurial Training: A Comparative Study across Fifteen European Countries

    ERIC Educational Resources Information Center

    Matricano, Diego

    2014-01-01

    This paper arises from the contents of the Lisbon Strategy, a set of cooperation policies stressing the role of education and training. The findings from a comparative study of the influence that entrepreneurial training--classified as formal or informal--can have on start-up expectations are analysed. The study covers fifteen European countries…

  12. Joachim Wach and the Study of Religion: A Comparative Approach.

    ERIC Educational Resources Information Center

    Georgia, Robert T.

    1992-01-01

    Discusses the life and career of Joachim Wach, a proponent of comparative study of religion (CSR). Reports that Wach envisioned "Religionwissenschaft," a unitary science taking a systematic approach to the study of religion using elements of theology, philosophy, and social science. Presents Wach's "basic and eternal" questions on ultimate…

  13. Political Ideology: A Comparative Study of Three Chicano Youth Organizations.

    ERIC Educational Resources Information Center

    Garcia, Richard A.

    The study investigated the political ideology of three Chicano youth groups in El Paso, Texas: Mexican American Youth Association (MAYA), Mexican American Political Association (MAPA), and the Alianza. Purpose of the study was to identify and compare the political ideas and attitudes of the three organizations. Questionnaires were administered to…

  14. Wage Rate Comparability Review Washington State Work Study Program.

    ERIC Educational Resources Information Center

    Washington State Higher Education Coordinating Board, Olympia.

    Washington State's Higher Education Coordinating Board undertook a review of the State Work Study (SWS) program requirements related to the classification and compensation of SWS positions at public colleges and universities. A task force studying wage rate comparability was convened to review statutory directives related to this issue and to…

  15. Living With and Learning about Radioactivity: A Comparative Conceptual Study.

    ERIC Educational Resources Information Center

    Alsop, Steve

    2001-01-01

    Documents a quasi-scientific comparative study of two groups of 'recent school leavers' in the UK. Studies non-science university undergraduates and explores whether people living with the immediacy and relevance of higher-than-average levels of radioactivity were more knowledgeable and emotionally detached than a similar group removed from this…

  16. A Comparative Study of Students' Achievement in Botany and Zoology

    ERIC Educational Resources Information Center

    Tamir, P.

    1974-01-01

    A comparative study of student achievement in botany and zoology based on data of 10 studies conducted in 20 countries. Up to age 14, students achieve better in zoology; after age 14, students achieve better in botany. Based on the findings, recommendations are suggested regarding curriculum planning, laboratory work and the need for specific…

  17. A comparative study between shielded and open coplanar waveguide discontinuities

    NASA Technical Reports Server (NTRS)

    Dib, Nihad I.; Harokopus, W. P., Jr.; Ponchak, G. E.; Katehi, L. P. B.

    1993-01-01

    A comparative study between open and shielded coplanar waveguide (CPW) discontinuities is presented. The space domain integral equation method is used to characterize several discontinuities such as the open-end CPW and CPW series stubs. Two different geometries of CPW series stubs (straight and bent stubs) are compared with respect to resonant frequency and radiation loss. In addition, the encountered radiation loss due to different CPW shunt stubs is evaluated experimentally. The notion of forced radiation simulation is presented, and the results of such a simulation are compared to the actual radiation loss obtained rigorously. It is shown that such a simulation cannot give reliable results concerning radiation loss from printed circuits.

  18. Computational comparative study of microwave probes for plasma density measurement

    NASA Astrophysics Data System (ADS)

    Kim, D. W.; You, S. J.; Kim, J. H.; Chang, H. Y.; Oh, W. Y.

    2016-06-01

    A microwave probe is known to be a suitable method to measure plasma density, even in the processing condition and is widely used in various environments of low-temperature processing plasmas. Various types of microwave probes have been researched and developed to measure the precise plasma density. Extensive research has been conducted to investigate each probes characteristic responding to the plasma parameters (plasma density, electron temperature, pressure, sheath width, and so forth) based on both experiments and simulations. However, a comparative study elucidating the relative characteristics of each probe has not been completed yet, despite the wide applications of the probes in processing plasma. We conduct a comparative study among the microwave probes using the numerical method of three-dimensional finite-difference time-domain simulation. In this study, the microwave probes are compared by investigating the precision of plasma density measurement under a comprehensive range of plasma parameters (plasma density, pressure, and sheath width).

  19. Comparing comparators: a look at control arms in kidney cancer studies over the years.

    PubMed

    Bracarda, S; Porta, C; Sisani, M; Marrocolo, F; Paglino, C; Hamzaj, A; D Buono, S; Sternberg, C N

    2015-01-01

    In the past decade, an increasing number of frequently positive randomised clinical trials have been completed, allowing new consideration of the present therapeutic armamentarium for advanced renal cell carcinoma. These studies were predominantly designed to compare the experimental drugs with 1 of 2 active control arms: interferon alpha-2a or sorafenib. Different from expectations, the final results of some of these studies were not in line with the predictions, and the reasons have not been fully investigated. Consequently, there is a great need for careful analysis of the studies carried out so far, chiefly the role and validity of the control arms. In this regard, the examination of patient baseline characteristics and other factors of potential interest seems fundamental for a correct analysis of the results of these trials and consequent optimal use of the available targeted agents. PMID:25375270

  20. Histological assessment of augmented jaw bone utilizing a new collagen barrier membrane compared to a standard barrier membrane to protect a granular bone substitute material.

    PubMed

    Friedmann, Anton; Strietzel, Frank Peter; Maretzki, Burghard; Pitaru, Sandu; Bernimoulin, Jean-Pierre

    2002-12-01

    Successful bone augmentation requires predictable space maintenance and adequate exclusion of those cells that lack osteogenetic potential from the defect area. Natural bone mineral is considered to be osteoconductive and is used as space maker in combination with membrane barrier techniques. The aim of this study was to compare qualitative histological results achieved by using deproteinized bovine bone mineral (DBBM) as a space maintainer and a new collagen barrier (Ossix, test group) vs. the same bone substitute and the standard e-PTFE membrane (Gore-Tex), control group). Twenty-eight patients were randomly assigned to the test or the control group. Seven months after augmentation procedures, biopsies were obtained at reentry and were analysed histomorphometrically. In all, 14 specimens of group I (test group, Ossix) and 13 specimens of group II (controls, PTFE-membranes) showed close qualitative similarity of their histologies. Histomorphometrically, total mineralized bone area was 42% +/- 18% in group I vs. 39% +/- 15% in group II. The unmineralized tissue area was 44% +/- 15% vs. 46% +/- 12% and the area of DBBM remnants 14% +/- 9% and 15% +/- 12%, respectively. The differences were statistically nonsignificant (Mann-Whitney test). The occurrence of barrier exposure did not interfere with the histological outcome either in the test or in the control group. The new collagen barrier combined with the DBBM provided qualitative bone regeneration comparable to the standard e-PTFE material combined with the same mineral. PMID:12519332

  1. [ADJUVANTED INFLUENZA VACCINES: DATA FROM DIRECT COMPARATIVE STUDIES].

    PubMed

    Chernikova, M I; Vasiliev, Yu M

    2015-01-01

    Vaccines are the cornerstone of influenza control, however available vaccines are subject to certain limitations. Adjuvanted vaccines are a promising approach, however available adjuvants have a suboptimal effectiveness and safety profile. Data from direct comparative trials are necessary for selection of optimal adjuvants among currently available and search for novel safe and effective adjuvants for next generation influenza vaccines. Data from published direct comparative studies of adjuvants for influenza vaccines are summarized, a lack of such studies is noted, especially those using adequate methods and designs and comparing adjuvants of major groups (nature/source and mechanism of action). Several promising approaches of adjuvant research and development could be identified: chitosan-based adjuvants, oil-in-water emulsions and multi-component formulations (depot + immune modulating components). PMID:26829860

  2. Rodents for comparative aging studies: from mice to beavers.

    PubMed

    Gorbunova, Vera; Bozzella, Michael J; Seluanov, Andrei

    2008-09-01

    After humans, mice are the best-studied mammalian species in terms of their biology and genetics. Gerontological research has used mice and rats extensively to generate short- and long-lived mutants, study caloric restriction and more. Mice and rats are valuable model organisms thanks to their small size, short lifespans and fast reproduction. However, when the goal is to further extend the already long human lifespan, studying fast aging species may not provide all the answers. Remarkably, in addition to the fast-aging species, the order Rodentia contains multiple long-lived species with lifespans exceeding 20 years (naked mole-rat, beavers, porcupines, and some squirrels). This diversity opens great opportunities for comparative aging studies. Here we discuss the evolution of lifespan in rodents, review the biology of slow-aging rodents, and show an example of how the use of a comparative approach revealed that telomerase activity coevolved with body mass in rodents. PMID:19424861

  3. A Comparative Study of Contract Training in Select Community Colleges.

    ERIC Educational Resources Information Center

    Updike, Katherine May

    In 1991, a study was conducted to compare contract training in selected community colleges providing service to business, industry, and government. A sample of 17 colleges was selected from the League for Innovation Contract Training Professional Network; and phone interviews were conducted with and questionnaires were returned by 16 of the 17…

  4. Louis, Hildegarde, and Mary: A Comparative Study in Infant Bilingualism.

    ERIC Educational Resources Information Center

    Bergman, Coral

    Studies of bilingual infants are in disagreement as to the point at which the child distinguishes two languages in his linguistic environment. In this paper, data from two classic works by linguist-parents on bilingual infants are compared with data collected from the author's own bilingual daughter. Five types of behavior are described which…

  5. Bullying and the Postgraduate Trainee Teacher: A Comparative Study

    ERIC Educational Resources Information Center

    Sewell, Keira; Cain, Tim; Woodgate-Jones, Alex; Srokosz, Anne

    2009-01-01

    In 2001, Maguire published the findings from a survey of the perceptions and experiences of secondary school trainee teachers of adult-adult bullying. The current paper reports on a study which aimed to compare the incidence and nature of bullying of postgraduate trainees in another English teacher training institution with the experiences of…

  6. Decentralized Management in Prison: A Comparative Case Study.

    ERIC Educational Resources Information Center

    Farmer, J. Forbes

    1994-01-01

    Conducted comparative case study of organizational climates in two prisons Findings from 149 staff members and 442 inmates revealed that flattening organizational structure without decentralizing authority seemed to have negative effects on staff supervisory relations and job satisfaction. Inmates reported better quality of life and more effective…

  7. Efficiency study comparing two helicopter planetary reduction stages

    NASA Technical Reports Server (NTRS)

    Krantz, Timothy L.; Handschuh, Robert F.

    1990-01-01

    A study was conducted to compare the efficiency of two helicopter transmission planetary reduction stages. Experimental measurements and analytical predictions were made. The analysis predicted and experiments verified that one planetary stage was a more efficient design due to the type of planet bearing used in the stage. The effects of torque, speed, lubricant type, and lubricant temperature on planetary efficiency are discussed.

  8. Treatment of Conduct Disorders in Childhood: A Comparative Study.

    ERIC Educational Resources Information Center

    Robinson, Elizabeth A.

    Children evidencing conduct disorders comprise the bulk of clinical referrals. Longitudinal studies have found that the prognosis for these children is poor in that the majority exhibit antisocial behavior in adulthood. In order to compare two methods of treatment, relationship-based and contingency management, 53 children (33 boys, 20 girls),…

  9. Comparative Study of Bacterial Growth in Magnet Fields

    NASA Astrophysics Data System (ADS)

    Smith, Derek; Masood, Samina

    It has been shown that magnetic fields affect bacterial growth. A comparative study of growth rates for gram-positive and gram-negative bacteria with different types of magnetic fields is done. Special focus is placed upon growth within liquid media, and the effect of magnetic fields relative to the chosen growth medium is considered.

  10. Comparative Study of Student Support Services of AIOU and UKOU

    ERIC Educational Resources Information Center

    Choudhry, Amtul Hafeez; Gujjar, Aijaz Ahmed; Hafeez, Muhammad Rashid

    2008-01-01

    This paper attempts to compare the availability, quality, similarities and differences of student support services in Allama Iqbal Open University (AIOU) and United Kingdom Open University (UKOU) and also to identify and enlist the deficiencies that AIOU students are facing in the student support services. The study found out that student support…

  11. Research Governance and the Role of Evaluation: A Comparative Study

    ERIC Educational Resources Information Center

    Molas-Gallart, Jordi

    2012-01-01

    Through a comparative study of the United Kingdom and Spain, this article addresses the effect of different research governance structures on the functioning and uses of research evaluation. It distinguishes three main evaluation uses: distributive, improvement, and controlling. Research evaluation in the United Kingdom plays important…

  12. The Syntax of Bilingual Children: A Comparative Study.

    ERIC Educational Resources Information Center

    Van Metre, Patricia D.

    The interview techniques developed by Carol Chomsky were used in a comparative study of the language acquisition of 32 bilingual and monolingual third grade students. After these students were matched for age, socioeconomic status, IQ, family environment (both parents in the home), and reading ability, they were placed in four…

  13. A Comparative Study of the Adjustment of Secondary School Students

    ERIC Educational Resources Information Center

    Devika R.

    2014-01-01

    Education is the ability to meet one's life. How the child adjusts with varying situations determines the success of life. The child's adjustment is determined by a number of factors like Home, Social, Educational and Financial adjustment. The investigator here aims to make a comparative study on the adjustment of secondary school students. The…

  14. It Pays to Compare: An Experimental Study on Computational Estimation

    ERIC Educational Resources Information Center

    Star, Jon R.; Rittle-Johnson, Bethany

    2009-01-01

    Comparing and contrasting examples is a core cognitive process that supports learning in children and adults across a variety of topics. In this experimental study, we evaluated the benefits of supporting comparison in a classroom context for children learning about computational estimation. Fifth- and sixth-grade students (N = 157) learned about…

  15. Political Responses to Reform: A Comparative Case Study.

    ERIC Educational Resources Information Center

    Noblit, George; And Others

    1991-01-01

    Comparative case studies assessed how the micropolitics of educational reform in two elementary schools affected one southeastern district's effort to professionalize teaching. The results indicate that teachers can use micropolitics to resist reform that, in these cases, legitimated centralization and control, and to heighten their control of…

  16. Comparative Studies on Sino-Canadian Higher Education

    ERIC Educational Resources Information Center

    Yang, Hong

    2008-01-01

    Today education is internationalization. Both China and Canada have their own strong merits of higher education. This paper approaches comparative studies on differences of Sino-Canadian higher education from new points, so as to achieve an inspiration to the development of Chinese higher education: preserve relative independence between higher…

  17. Generation 1.5 Written Error Patterns: A Comparative Study

    ERIC Educational Resources Information Center

    Doolan, Stephen M.; Miller, Donald

    2012-01-01

    In an attempt to contribute to existing research on Generation 1.5 students, the current study uses quantitative and qualitative methods to compare error patterns in a corpus of Generation 1.5, L1, and L2 community college student writing. This error analysis provides one important way to determine if error patterns in Generation 1.5 student…

  18. A Study Comparing Electronic Mail and Voice Messaging Channels.

    ERIC Educational Resources Information Center

    Gluck, Myke; And Others

    1991-01-01

    Describes a study that explored differences in computer-mediated communication messaging by comparing electronic mail and voice messaging used for giving directions. Highlights include a computational linguistic framework that examines differences between written and oral English, models of direction provision, and hypotheses based on preliminary…

  19. Using Comparative Online Media to Study the Iraq War

    ERIC Educational Resources Information Center

    Eaton, Jana Sackman

    2004-01-01

    The war in Iraq and the aftermath are receiving media attention around the globe. A plethora of media reports from many other countries is now available online in English. This article recommends possible approaches to developing comparative media studies and provides URLs to specific sources. The NCSS standards addressed by these lessons include:…

  20. A Comparative Study of Two Acoustic Measures of Hypernasality

    ERIC Educational Resources Information Center

    Vogel, Adam P.; Ibrahim, Hasherah M.; Reilly, Sheena; Kilpatrick, Nicky

    2009-01-01

    Purpose: This study aimed to compare 2 quantitative acoustic measures of nasality in children with cleft lip and palate (CLP) and healthy controls using formalized perceptual assessment as a guide. Method: Fifty participants (23 children with CLP and 27 age- and gender-matched healthy controls) aged between 4 and 12 years produced a variety of…

  1. Different Underlying Neurocognitive Deficits in Developmental Dyslexia: A Comparative Study

    ERIC Educational Resources Information Center

    Menghini, D.; Finzi, A.; Benassi, M.; Bolzani, R.; Facoetti, A.; Giovagnoli, S.; Ruffino, M.; Vicari, S.

    2010-01-01

    The aim of this study was to investigate the role of several specific neurocognitive functions in developmental dyslexia (DD). The performances of 60 dyslexic children and 65 age-matched normally reading children were compared on tests of phonological abilities, visual processing, selective and sustained attention, implicit learning, and executive…

  2. A Comparative Study of Students' Attitudes Toward Education.

    ERIC Educational Resources Information Center

    Quintanar, Rosalinda

    The comparative analysis of students' attitudes included Mexican American, Anglo, and Asian students (from Thailand, Taiwan, and the Philippines). A Likert scale was used to measure all attitudes. All analysis performed utilized cross tabulation and chi square. The attitudes studied were reasons for going to college; concept of an educated person…

  3. Comparative Analysis, Global Policy Studies and the Human Condition.

    ERIC Educational Resources Information Center

    Bertsch, Gary K.

    This paper examines the role that comparative analysis and global policy studies can play in explaining the human condition in the contemporary world. It investigates economic well-being, one dimension of the human condition, and examines some of the attributes that represent it and some of the forces that affect it in villages, social groupings,…

  4. Introduction to a Comparative Study of Educational Administration.

    ERIC Educational Resources Information Center

    Lynch, Patrick D.

    Comparative educational administration is not yet a recognized field, although a number of works concerning cross-cultural educational literature are directly applicable to such studies. Four themes are apparent in relevant works. Beginning in the 19th century, the earliest works focused on European schools in the hopes America could learn from…

  5. TRANSMISSION NETWORK PLANNING METHOD FOR COMPARATIVE STUDIES (JOURNAL VERSION)

    EPA Science Inventory

    An automated transmission network planning method for comparative studies is presented. This method employs logical steps that may closely parallel those taken in practice by the planning engineers. Use is made of a sensitivity matrix to simulate the engineers' experience in sele...

  6. Comparative analysis of the space power architecture studies

    NASA Technical Reports Server (NTRS)

    Sovie, Ronald J.

    1988-01-01

    The Strategic Defense Initiative Organization (SDIO) has recently completed the initial phase of Space Power Architecture Studies (SPAS). The initial effort consisted of three major contracted efforts and a comparative analysis performed by the SDIO Independent Evaluation Group (IEG) and the IEG Field Support Team. The purpose of the SPAS effort was to evaluate a wide range of power systems for SDIO applications using a wide range of attributes other than power-system mass and volume. Open cycle, closed cycle, and closed power system/weapon platform concepts were studied. The purpose of this paper is to summarize the salient results of these studies, identify important trends and future study needs.

  7. A comparative study of nuclear accident consequences for Hong Kong

    SciTech Connect

    Ching, E.M.K.; Yeung, Mankit Ray )

    1993-02-01

    A two-dimensional dispersion and consequence model called RADIS has been developed and used to perform a site-specific investigation of the consequences and risks for Hong Kong as a result of a potential accident at the Daya Bay Nuclear Power Station. The study uses the 1986 Hong Kong weather and demographic data to determine the accident consequences for Hong Kong. The overall cumulative occurrence frequency distributions of early fatality, early injury, latent cancer, and thyroid nodule are compared with those of WASH-1400 and a United Kingdom Atomic Energy Authority (UKAEA) study. This study is generally consistent with the WASH-1400 results and exhibits less conservatism than the UKAEA study.

  8. Relationship between Fibroblast Growth Factor 23 and Biochemical and Bone Histomorphometric Alterations in a Chronic Kidney Disease Rat Model Undergoing Parathyroidectomy

    PubMed Central

    Liao, Hung-Wei; Hung, Peir-Haur; Hsiao, Chih-Yen; Liou, Hung-Hsiang; Lin, Hsin-Shih; Huang, Tsang-Hai; Jou, I-Ming; Tsai, Kuen-Jer

    2015-01-01

    Background Phosphate burden in chronic kidney disease (CKD) leads to elevated serum fibroblast factor-23 (FGF-23) levels, secondary hyperparathyroidism and chronic kidney disease-mineral bone disorder (CKD-MBD). However dissociated hyperphosphatemia and low serum FGF-23 concentrations have been observed in experimentally parathyoridectomized rats. The relationships between serum mineral, hormone, and bone metabolism may be altered in the presence of CKD. The aim of our study was to investigate whether a consistent relationship existed between serum FGF-23 levels, specific serum biochemical markers, and histomorphometric parameters of bone metabolism in a parathyroidectomized CKD animal model. Results Sprague Dawley rats were divided into 3 groups: parathyroidectomy (PTX) and CKD (PTX+CKD, 9 rats), CKD without PTX (CKD, 9 rats), and neither PTX nor CKD (sham-operated control, 8 rats); CKD was induced by partial nephrectomy. At 8 weeks after partial nephrectomy, serum biomarkers were measured. Bone histomorphometries of the distal femoral metaphyseal bone were analyzed. The mean serum FGF-23 levels and mean bone formation rate were the highest in the CKD group and the lowest in the PTX+CKD group. Bone volume parameters increased significantly in the PTX+CKD group. Pearson’s correlation revealed that serum FGF-23 levels associated with those of intact parathyroid hormone, phosphate, collagen type I C-telopeptide, and calcium. Univariate linear regression showed that serum FGF-23 values correlated with bone formation rate, bone volume, and osteoid parameters. Stepwise multivariate regression analysis revealed that circulating FGF-23 values were independently associated with bone volume and thickness (β = -0.737; p < 0.001 and β = -0.526; p = 0.006, respectively). Serum parathyroid hormone levels independently correlated with bone formation rate (β = 0.714; p < 0.001) while collagen type I C-telopeptide levels correlated with osteoid parameter. Conclusion Serum FGF

  9. Comparative study of texture detection and classification algorithms

    NASA Astrophysics Data System (ADS)

    Koltsov, P. P.

    2011-08-01

    A description and results of application of the computer system PETRA (performance evaluation of texture recognition algorithms) are given. This system is designed for the comparative study of texture analysis algorithms; it includes a database of textured images and a collection of software implementations of texture analysis algorithms. The functional capabilities of the system are illustrated using texture classification examples. Test examples are taken from the Brodatz album, MeasTech database, and a set of aerospace images. Results of a comparative evaluation of five well-known texture analysis methods are described—Gabor filters, Laws masks, ring/wedge filters, gray-level cooccurrence matrices (GLCMs), and autoregression image model.

  10. Ergonomic intervention, workplace exercises and musculoskeletal complaints: a comparative study

    PubMed Central

    Mehrparvar, Amir Houshang; Heydari, Mohammad; Mirmohammadi, Seyyed Jalil; Mostaghaci, Mehrdad; Davari, Mohammad Hossein; Taheri, Mahmoud

    2014-01-01

    Background: Musculoskeletal disorders are among the most prevalent occupational disorders in different jobs such as office work. Some interventions such as ergonomic modifications and workplace exercises are introduced as the methods for alleviating these disorders. In this study we compared the effect of ergonomic modifications and workplace exercises on musculoskeletal pain and discomfort in a group of office workers. Methods: In an interventional study on office workers, the effect of two interventions was compared. Ergonomic modification consisted of correcting the arrangement of workstation and changing some equipment; workplace exercises included stretching exercises focusing on neck, shoulders, low back, and hand and wrist. Musculoskeletal complaints were assessed and compared before and after 1 month interventions. Results: The frequency of musculoskeletal complaints was high before the study. Both interventions significantly reduced complaints in a similar manner except for low back pain which was reduced in exercise group more than the other group. Conclusion: In this study we found a beneficial short-term effect for both ergonomic modifications and stretching work-place exercises on reducing musculoskeletal pain in office workers. PMID:25405134

  11. Comparative study of turbulence models in predicting hypersonic inlet flows

    NASA Technical Reports Server (NTRS)

    Kapoor, Kamlesh; Anderson, Bernhard H.; Shaw, Robert J.

    1992-01-01

    A numerical study was conducted to analyze the performance of different turbulence models when applied to the hypersonic NASA P8 inlet. Computational results from the PARC2D code, which solves the full two-dimensional Reynolds-averaged Navier-Stokes equation, were compared with experimental data. The zero-equation models considered for the study were the Baldwin-Lomax model, the Thomas model, and a combination of the Baldwin-Lomax and Thomas models; the two-equation models considered were the Chien model, the Speziale model (both low Reynolds number), and the Launder and Spalding model (high Reynolds number). The Thomas model performed best among the zero-equation models, and predicted good pressure distributions. The Chien and Speziale models compared very well with the experimental data, and performed better than the Thomas model near the walls.

  12. Comparative study of turbulence models in predicting hypersonic inlet flows

    NASA Technical Reports Server (NTRS)

    Kapoor, Kamlesh; Anderson, Bernhard H.; Shaw, Robert J.

    1992-01-01

    A numerical study was conducted to analyze the performance of different turbulence models when applied to the hypersonic NASA P8 inlet. Computational results from the PARC2D code, which solves the full two-dimensional Reynolds-averaged Navier-Stokes equation, were compared with experimental data. The zero-equation models considered for the study were the Baldwin-Lomax model, the Thomas model, and a combination of the Baldwin-Lomax and Thomas models; the two-equation models considered were the Chien model, the Speziale model (both low Reynolds number), and the Launder and Spalding model (high Reynolds number). The Thomas model performed best among the zero-equation models, and predicted good pressure distributions. The Chien and Speziale models compared wery well with the experimental data, and performed better than the Thomas model near the walls.

  13. A comparative study of primary and secondary stereotypies.

    PubMed

    Ghosh, Debabrata; Rajan, Prashant V; Erenberg, Gerald

    2013-12-01

    This study compares primary stereotypies (repetitive, self-stimulating, and seemingly nonsensical movements that can occur within typically developing children) and secondary stereotypies (those occurring within autistic or mentally retarded children). Utilizing a retrospective chart review from 1995 to 2010, the current study compares primary and secondary stereotypies by the application of a classification system that organizes the movement by its type (motor only, phonic only, mixed) and complexity. In addition, it investigates other parameters associated with the movements such as duration, frequency, age, functional impairment, and progression. The sample group consisted of 28 primary and 28 secondary cases. Primary stereotypies were predominantly motor, simple, of shorter duration, and of less frequency, whereas secondary stereotypies had more vocalization, complexity, longer durations, and higher frequencies. Moreover, functional impairment due to stereotypies was noted in 3 primary and 7 secondary cases, and worsening of stereotypies was noted in 70% of primary versus 44% of secondary cases. PMID:23143719

  14. Comparative studies of silicon photomultipliers and traditional vacuum photomultiplier tubes

    NASA Astrophysics Data System (ADS)

    Shi, Feng; Lü, Jun-Guang; Lu, Hong; Wang, Huan-Yu; Ma, Yu-Qian; Hu, Tao; Zhou, Li; Cai, Xiao; Sun, Li-Jun; Yu, Bo-Xiang; Fang, Jian; Xie, Yu-Guang; An, Zheng-Hua; Wang, Zhi-Gang; Gao, Min; Li, Xin-Qiao; Xu, Yan-Bing; Wang, Ping; Sun, Xi-Lei; Zhang, Ai-Wu; Xue, Zhen; Liu, Hong-Bang; Wang, Xiao-Dong; Zhao, Xiao-Yun; Zheng, Yang-Heng; Meng, Xiang-Cheng; Wang, Hui

    2011-01-01

    Silicon photomultipliers (SiPMs) are a new generation of semiconductor-based photon counting devices with the merits of low weight, low power consumption and low voltage operation, promising to meet the needs of space particle physics experiments. In this paper, comparative studies of SiPMs and traditional vacuum photomultiplier tubes (PMTs) have been performed regarding the basic properties of dark currents, dark counts and excess noise factors. The intrinsic optical crosstalk effect of SiPMs was evaluated.

  15. Comparative study of acceleration transducers for biomedical applications

    NASA Astrophysics Data System (ADS)

    Buchczik, Dariusz; Wyżgolik, Roman; Pietraszek, Stanisław

    2006-10-01

    The results of comparative studies of the metrological parameters of acceleration transducers constructed in Institute of Electronics, Silesian University of Technology is presented in this article. The construction of the transducers is based on commercially available monolithic accelerometers and optimized for biomedical applications. The parameters determined during the tests are similar to the parameters of the monolithic accelerometers declared by their manufacturers. It proofs that both the mechanical and the electronic construction of the transducers are correct.

  16. [Comparative study of two dried intradermal BCG vaccines (author's transl)].

    PubMed

    Fillastre, C; Guerin, N; Danusantoso, H; Sardadi, S

    1979-01-01

    Two BCG vaccines prepared from the same strain were studied clinically in Indonesia and in France. The concentration in culturable particles was comparable. Observed differences in the Mantoux results are discussed. The French results, based on use in a temperate climate by a specialized team, on well nourished children, appear better than the Indonesian findings. Further steps should be undertaken to improve results in Indonesia. PMID:539694

  17. A Comparative Study of Heat Transfer in Metallic Materials

    NASA Astrophysics Data System (ADS)

    Pǎucǎ, Adina; Hepuţ, Teodor; Pinca-Bretotean, Camelia; Stoica, Diana

    2011-09-01

    Rolling of metallic materials with heat transfer occurs as a result of interaction between the workpiece and the rolling cylinders incandescent. Heat transferred by diffusion into the cylinders generates variable temperature fields. These fields produce variable temperature thermal stress in each rotation cycle of rolling cylinders. This paper aims at mathematical modeling of variable temperature fields, using Matlab. These diagrams obtained are compared with those obtained following experimental study of the thermal lamination cylinders for 5 states isochronous temperature.

  18. Low-level laser therapy (LLLT) reduces inflammatory infiltrate and enhances skeletal muscle repair: Histomorphometric parameters

    NASA Astrophysics Data System (ADS)

    Paiva-Oliveira, E. L.; Lima, N. C.; Silva, P. H.; Sousa, N. T. A.; Barbosa, F. S.; Orsini, M.; Silva, J. G.

    2012-09-01

    Low level laser therapy (LLLT) has been suggested as an effective therapeutics in inflammatory processes modulation and tissue repairing. However, there is a lack of studies that analyze the anti-inflammatory effects of the infrared lasers in muscular skeletal injury. The aim of this study was to investigate the effects of low-level laser therapy 904 nm in the repair process of skeletal muscle tissue. Swiss mice were submitted to cryoinjury and divided in test (LLLT-treated) and control groups. Histological sections were stained with hematoxylin-eosin to assess general morphology and inflammatory influx, and Picrossirus to quantify collagen fibers deposition. Our results showed significant reduction in inflammatory infiltrated in irradiated mice after 4 days of treatment compared to control ( p = 0.01). After 8 days, the irradiated group showed high levels at regenerating myofibers with significant statistically differences in relation at control group ( p < 0.01). Collagen deposition was significantly increased in the final stages of regeneration at test group, when compared with control group ( p = 0.05). Our data suggests that LLLT reduces the inflammatory response in the initial stages of injury and accelerates the process of muscular tissue repair.

  19. Comparative Study of Permeatal Sandwich Tympanoplasty and Postaural Underlay Technique

    PubMed Central

    Nagpure, Prakash Shankarrao; Yadav, Manish; Chavan, Sushil

    2016-01-01

    Introduction Tympanoplasty is the most common operation performed by an Otolaryngologist right from the period of residency. During the last hundred years various modifications in this surgical technique have come up because of continued efforts made by otologists all over the world to achieve the best surgical outcome. Aim To compare the graft take up and complications associated with the Permeatal Sandwich Tympanoplasty performed with the use of Otoendoscope and traditional Postaural Underlay technique of Tympanoplasty from 1st September 2014 to 30th August 2015. Materials and Methods Patients attending the ENT OPD, suffering from Chronic Suppurative Otitis Media (CSOM) were selected on the basis of type of perforation and their workup was done to assess the candidature for tympanoplasty. Results A total of 100 patients were included in the study and the overall graft take was 92.3% in cases of Permeatal Sandwich technique as compared to 64.58% in the case of postaural underlay technique, with a majority of the failures in the large central perforation group rendering a p = 0.021 for patients operated for Large perforations, p = 0.036 for moderate perforations and p = 0.476 for small perforations. The overall p = 0.000649 which is highly significant. On comparing the complications there were only 2 cases in Permeatal Sandwich Technique compared to 25 cases in Postaural Underlay technique rendering a highly significant p-value 0f 0.000000348. There was a difference in hearing improvement with majority of the cases improving to the range of 16-25 dB in Permeatal Sandwich technique compared to 26-45 dB in Postaural Underlay technique. Conclusion Permeatal Sandwich technique produce much better results when compared with Postaural approach in terms of graft take up, complications and hearing improvement. PMID:27190842

  20. Osseointegration and biocompatibility of different metal implants - a comparative experimental investigation in sheep

    PubMed Central

    2012-01-01

    Background In the present study, 4 different metallic implant materials, either partly coated or polished, were tested for their osseointegration and biocompatibility in a pelvic implantation model in sheep. Methods Materials to be evaluated were: Cobalt-Chrome (CC), Cobalt-Chrome/Titanium coating (CCTC), Cobalt-Chrome/Zirconium/Titanium coating (CCZTC), Pure Titanium Standard (PTST), Steel, TAN Standard (TANST) and TAN new finish (TANNEW). Surgery was performed on 7 sheep, with 18 implants per sheep, for a total of 63 implants. After 8 weeks, the specimens were harvested and evaluated macroscopically, radiologically, biomechanically (removal torque), histomorphometrically and histologically. Results Cobalt-Chrome screws showed significantly (p = 0.031) lower removal torque values than pure titanium screws and also a tendency towards lower values compared to the other materials, except for steel. Steel screws showed no significant differences, in comparison to cobalt-chrome and TANST, however also a trend towards lower torque values than the remaining materials. The results of the fluorescence sections agreed with those of the biomechanical test. Histomorphometrically, there were no significant differences of bone area between the groups. The BIC (bone-to-implant-contact), used for the assessment of the osseointegration, was significantly lower for cobalt-chrome, compared to steel (p = 0.001). Steel again showed a lower ratio (p = 0.0001) compared to the other materials. Conclusion This study demonstrated that cobalt-chrome and steel show less osseointegration than the other metals and metal-alloys. However, osseointegration of cobalt-chrome was improved by zirconium and/or titanium based coatings (CCTC, TANST, TAN, TANNEW) being similar as pure titanium in their osseointegrative behavior. PMID:22400715

  1. Comparative Statistical Study of Some SAP UI Technologies

    NASA Astrophysics Data System (ADS)

    Berdie, Adela; Osaci, Mihaela; Dan Lemle, Ludovic

    2011-09-01

    The goal of this paper is to present a comparative study on some web UI (User Interface) technologies that involve the creation of web applications on the platform SAP Net Weaver AS 7.01 of the integrated SAP (System Application Products) system. The attention will be directed mainly to the ABAP (Advanced Business Application Programing) development environment and to the Web Dynpro (WD) technologies, Floor Plan Manager (FPM) and Web Client UI. Through this study, we make an assesment regarding the decision of choosing a technology for the realisation of a project which consists of a web application.

  2. Image based 3D city modeling : Comparative study

    NASA Astrophysics Data System (ADS)

    Singh, S. P.; Jain, K.; Mandla, V. R.

    2014-06-01

    3D city model is a digital representation of the Earth's surface and it's related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing rapidly for various engineering and non-engineering applications. Generally four main image based approaches were used for virtual 3D city models generation. In first approach, researchers were used Sketch based modeling, second method is Procedural grammar based modeling, third approach is Close range photogrammetry based modeling and fourth approach is mainly based on Computer Vision techniques. SketchUp, CityEngine, Photomodeler and Agisoft Photoscan are the main softwares to represent these approaches respectively. These softwares have different approaches & methods suitable for image based 3D city modeling. Literature study shows that till date, there is no complete such type of comparative study available to create complete 3D city model by using images. This paper gives a comparative assessment of these four image based 3D modeling approaches. This comparative study is mainly based on data acquisition methods, data processing techniques and output 3D model products. For this research work, study area is the campus of civil engineering department, Indian Institute of Technology, Roorkee (India). This 3D campus acts as a prototype for city. This study also explains various governing parameters, factors and work experiences. This research work also gives a brief introduction, strengths and weakness of these four image based techniques. Some personal comment is also given as what can do or what can't do from these softwares. At the last, this study shows; it concluded that, each and every software has some advantages and limitations. Choice of software depends on user requirements of 3D project. For normal visualization project, SketchUp software is a good option. For 3D documentation record, Photomodeler gives good result. For Large city

  3. A comparative study of fluoride release from two different sealants

    PubMed Central

    Ananda, Shimoga-Raju

    2014-01-01

    Objectives: The introduction of fluoride releasing sealants and glass ionomer cements as fissure sealants adds another dimension to prevention of pit and fissure caries. The ability of resin sealants and glass ionomer cements to release fluoride on a long term basis to the sealed enamel and the adjacent unsealed pit and fissure and cuspal incline enamel may allow for further reduction in pit and fissure caries experience for children. Hence, the study was conducted to compare the amount of fluoride release in the plaque after placing fluoride releasing pit and fissure sealants and glass ionomer fissure sealants used in Atraumatic Restorative Treatment (ART) approach. To compare the fluoride release of both the materials at the different time intervals. Material and Methods: A total of 60 school going children were included in this study. Before application of the sealants, baseline plaque fluoride levels were estimated from all the study subjects. After application of sealants again the same was estimated at an interval of 24 hour, 9 days, 2 weeks and 4 weeks. Results: The peak plaque fluoride levels were achieved at 24 hours after application of fissure sealants in all the groups. Conclusions: Within the limitation of the study, the present study indicated that fluoride releasing fissure sealants may act as a source of fluoride in plaque which will help in preventing pit and fissure and smooth surface caries in the tooth sealed with fissure sealants. Key words:Plaque fluoride, pit and fissures sealants, dental caries. PMID:25674315

  4. Comparing protein VEGF inhibitors: In vitro biological studies

    SciTech Connect

    Yu, Lanlan; Liang, Xiao Huan; Ferrara, Napoleone

    2011-05-06

    Highlights: {yields} VEGF is a mediator of angiogenesis. {yields} VEGF inhibitors have clinical applications in cancer and eye disorders. {yields} Five protein VEGF inhibitors were compared for their ability to inhibit. {yields} VEGF-induced activities in cultured endothelial cells. -- Abstract: VEGF inhibitors are widely used as a therapy for tumors and intravascular neovascular disorders, but limited and conflicting data regarding their relative biological potencies are available. The purpose of the study is to compare different protein VEGF inhibitors for their ability to inhibit VEGF-stimulated activities. We tested ranibizumab, the full-length variant of ranibizumab (Mab Y0317), bevacizumab, the VEGF-TrapR1R2 and Flt(1-3)-IgG in bioassays measuring VEGF-stimulated proliferation of bovine retinal microvascular endothelial cells or chemotaxis of human umbilical vein endothelial cells (HUVEC). The inhibitors were also compared for their ability to inhibit MAP kinase activation in HUVECs following VEGF addition. Ranibizumab, VEGF-TrapR1R2 and Flt(1-3)-IgG had very similar potencies in the bioassays tested. Bevacizumab was over 10-fold less potent than these molecules. Mab Y0317 was over 30-fold more potent than bevacizumab. The findings reported in this manuscript describe important intrinsic characteristics of several VEGF inhibitors that may be useful to design and interpret preclinical or clinical studies.

  5. A comparative study of bifidobacteria in human babies and adults

    PubMed Central

    KHONSARI, Shadi; SUGANTHY, Mayuran; BURCZYNSKA, Beata; DANG, Vu; CHOUDHURY, Manika; PACHENARI, Azra

    2015-01-01

    The composition and diversity of the gut microbiota are known to be different between babies and adults. The aim of this project was to compare the level of bifidobacteria between babies and adults and to investigate the influence of lifestyle factors on the level of this bacterium in the gut. During this study, the levels of bifidobacteria in 10 human babies below 2 years of age were compared with that of 10 human adults above 40 years. The level of bifidobacteria proved to be significantly higher in babies in comparison with adults. This investigation concluded that a combination of several factors, such as age, diet, and BMI, has an important effect on the level of bifidobacteria in adults, while in babies, a combination of diet and age may influence the level of intestinal bifidobacteria. PMID:27200263

  6. Comparative studies of industrial grade carbon black powders

    NASA Astrophysics Data System (ADS)

    Chawla, Komal; Chauhan, Alok P. S.

    2016-05-01

    Comparative studies of two dissimilar industrial grade Carbon Black (CB) powders (N375 and N405) were conducted. The structure, surface area and particle size are the three important characteristics of CB powder that determine their processability and application as filler in preparing rubber compounds. The powders were characterized for their structure using dibutyl phthalate absorption (DBPA), particle size via laser particle size analyzer and surface area by nitrogen adsorption method. The structural characterization showed that N405 had lower DBPA in comparison to N375, confirming low structure of N405 grade CB powder. It was observed from the particle size analysis that N375 was coarser than N405 grade CB. The total surface area values were determined by the BET method based on the cross sectional area of the nitrogen molecule. N375, a coarse grade CB powder with high structure, depicted less surface area as compared to N405.

  7. A comparative study of bifidobacteria in human babies and adults.

    PubMed

    Khonsari, Shadi; Suganthy, Mayuran; Burczynska, Beata; Dang, Vu; Choudhury, Manika; Pachenari, Azra

    2016-01-01

    The composition and diversity of the gut microbiota are known to be different between babies and adults. The aim of this project was to compare the level of bifidobacteria between babies and adults and to investigate the influence of lifestyle factors on the level of this bacterium in the gut. During this study, the levels of bifidobacteria in 10 human babies below 2 years of age were compared with that of 10 human adults above 40 years. The level of bifidobacteria proved to be significantly higher in babies in comparison with adults. This investigation concluded that a combination of several factors, such as age, diet, and BMI, has an important effect on the level of bifidobacteria in adults, while in babies, a combination of diet and age may influence the level of intestinal bifidobacteria. PMID:27200263

  8. A Comparative Study on Emerging Electric Vehicle Technology Assessments

    SciTech Connect

    Ford, Jonathan; Khowailed, Gannate; Blackburn, Julia; Sikes, Karen

    2011-03-01

    Numerous organizations have published reports in recent years that investigate the ever changing world of electric vehicle (EV) technologies and their potential effects on society. Specifically, projections have been made on greenhouse gas (GHG) emissions associated with these vehicles and how they compare to conventional vehicles or hybrid electric vehicles (HEVs). Similar projections have been made on the volumes of oil that these vehicles can displace by consuming large amounts of grid electricity instead of petroleum-based fuels. Finally, the projected rate that these new vehicle fleets will enter the market varies significantly among organizations. New ideas, technologies, and possibilities are introduced often, and projected values are likely to be refined as industry announcements continue to be made. As a result, over time, a multitude of projections for GHG emissions, oil displacement, and market penetration associated with various EV technologies has resulted in a wide range of possible future outcomes. This leaves the reader with two key questions: (1) Why does such a collective range in projected values exist in these reports? (2) What assumptions have the greatest impact on the outcomes presented in these reports? Since it is impractical for an average reader to review and interpret all the various vehicle technology reports published to date, Sentech Inc. and the Oak Ridge National Laboratory have conducted a comparative study to make these interpretations. The primary objective of this comparative study is to present a snapshot of all major projections made on GHG emissions, oil displacement, or market penetration rates of EV technologies. From the extensive data found in relevant publications, the key assumptions that drive each report's analysis are identified and 'apples-to-apples' comparisons between all major report conclusions are attempted. The general approach that was taken in this comparative study is comprised of six primary steps: (1

  9. Comparative study of clinical pulmonary surfactants using atomic force microscopy

    PubMed Central

    Zhang, Hong; Fan, Qihui; Wang, Yi E.; Neal, Charles R.; Zuo, Yi Y.

    2016-01-01

    Clinical pulmonary surfactant is routinely used to treat premature newborns with respiratory distress syndrome, and has shown great potential in alleviating a number of neonatal and adult respiratory diseases. Despite extensive study of chemical composition, surface activity, and clinical performance of various surfactant preparations, a direct comparison of surfactant films is still lacking. In this study, we use atomic force microscopy to characterize and compare four animal-derived clinical surfactants currently used throughout the world, i.e., Survanta, Curosurf, Infasurf and BLES. These modified-natural surfactants are further compared to dipalmitoyl phosphatidylcholine (DPPC), a synthetic model surfactant of DPPC:palmitoyl-oleoyl phosphatidylglycerol (POPG) (7:3), and endogenous bovine natural surfactant. Atomic force microscopy reveals significant differences in the lateral structure and molecular organization of these surfactant preparations. These differences are discussed in terms of DPPC and cholesterol contents. We conclude that all animal-derived clinical surfactants assume a similar structure of multilayers of fluid phospholipids closely attached to an interfacial monolayer enriched in DPPC, at physiologically relevant surface pressures. This study provides the first comprehensive survey of the lateral structure of clinical surfactants at various surface pressures. It may have clinical implications on future application and development of surfactant preparations. PMID:21439262

  10. Spiritual coping in rehabilitation- a comparative study: part 2.

    PubMed

    Baldacchino, Donia; Torskenaes, Kristina; Kalfoss, Mary; Borg, Josette; Tonna, Aaron; Debattista, Clifford; Decelis, Neville; Mifsud, Rodianne

    Spiritual coping, which may or may not contain religiosity, may enhance adaptation of clients with chronic illness. Part 1 of this article (Baldacchino et al, 2013) presented the research methodology of this cross-sectional comparative study, which explored the spiritual coping of clients with chronic illness receiving rehabilitation services in Malta (n=44) (lower limb amputation: n=10, chronic heart disease: n=9, osteoarthritis in an institution: n=10 and in the community: n=15) and Norway (n=16) (post-hip/shoulder surgery: n=5; chronic heart disease: n=5; chronic pain: n=6). Data were collected from seven purposive samples by focus groups. Roy's adaptation model (1984) and Neuman's Systems Model (2010) guided the study. Part2 discusses the findings, which consist of one main spiritual coping theme and three sub-themes: 'adopting religious coping strategies, relationship with God, and time for reflection and counting one's blessings'. Commonalities were found in the findings except in one dimension, which was found only in the Malta group, that is, being supported by others with a similar condition. This difference may be a result of the environment in the rehabilitation centres, cultural, and geographical differences between the two countries. While considering the limitations of this study, recommendations are proposed to the rehabilitation and education sectors and further trans-cultural comparative longitudinal research with mixed method approach on various clients with acute, chronic and life-threatening illness. PMID:23588017

  11. Discourse Formation in Comparative Education. 4th, Revised Edition. Comparative Studies Series. Volume 10

    ERIC Educational Resources Information Center

    Schriewer, Jurgen, Ed.

    2012-01-01

    New theories and theory-based methodological approaches have found their way into Comparative Education--just as into Comparative Social Science more generally--in increasing number in the recent past. The essays of this volume express and critically discuss quite a range of these positions such as, inter alia, the theory of self-organizing social…

  12. Comparative study of minutiae selection algorithms for ISO fingerprint templates

    NASA Astrophysics Data System (ADS)

    Vibert, B.; Charrier, C.; Le Bars, J.-M.; Rosenberger, C.

    2015-03-01

    We address the selection of fingerprint minutiae given a fingerprint ISO template. Minutiae selection plays a very important role when a secure element (i.e. a smart-card) is used. Because of the limited capability of computation and memory, the number of minutiae of a stored reference in the secure element is limited. We propose in this paper a comparative study of 6 minutiae selection methods including 2 methods from the literature and 1 like reference (No Selection). Experimental results on 3 fingerprint databases from the Fingerprint Verification Competition show their relative efficiency in terms of performance and computation time.

  13. Comparative DFT study of crystalline ammonium perchlorate and ammonium dinitramide.

    PubMed

    Zhu, Weihua; Wei, Tao; Zhu, Wei; Xiao, Heming

    2008-05-22

    The electronic structure, vibrational properties, absorption spectra, and thermodynamic properties of crystalline ammonium perchlorate (AP) and ammonium dinitramide (ADN) have been comparatively studied using density functional theory in the local density approximation. The results shows that the p states for the two solids play a very important role in their chemical reaction. From the low frequency to high frequency region, ADN has more motion modes for the vibrational frequencies than AP. The absorption spectra of AP and ADN display a few, strong bands in the fundamental absorption region. The thermodynamic properties show that ADN is easier to decompose than AP as the temperature increases. PMID:18396853

  14. Comparative study for better adjuvant with ropivacaine in epidural anesthesia

    PubMed Central

    Soni, Pramila

    2016-01-01

    Background: Better adjuvants for epidural analgesia are still evolving. Dexmedetomidine that is alpha-2 agonist can be used as an adjuvant in epidural analgesia and anesthesia. Aims: The aim of this study was to compare the effect of dexmedetomidine versus clonidine in combination with ropivacaine in epidural anesthesia on intraoperative and postoperative analgesia, to find out the better adjuvant for regional anesthesia. Settings and Design: Randomized control trial. Materials and Methods: Sixty adult patients (18–60 years) with American Society of Anesthesiologists (ASA) 1/ASA 2 grade and undergoing lower abdominal and lower limbs surgeries were included and randomized into three groups of 20 patients each. Group 1 - received ropivacaine with normal saline. Group 2 - received ropivacaine with dexmedetomidine. Group 3 - received ropivacaine with clonidine. Statistical Analysis: Mean and Standard deviation were calculated. All the data were analyzed using analysis of variance and Chi-square test. The value of P< 0.05 was considered significant. Results: All the three groups were comparable with respect to age, sex, and ASA grade. There was statistically significant mean time to reach T10 sensory block level (15.8, 5.7, 9.6 min in Groups 1, 2, and 3, respectively). The maximum duration of analgesia was statistically higher in Group 2 patients (383.7 vs. 365.3 and 280.5 min in Group 3 and Group 1, respectively). The mean time to reach motor block was significantly shorter in Group 2. Side effects were comparable in all groups with statistically insignificant fall in mean arterial pressure and hypotension was noted with Group 2. Conclusion: We concluded that the patients receiving the addition of dexmedetomidine to ropivacaine in epidural anesthesia had a faster onset and longer duration of sensory and motor blockade. Dexmedetomidine in comparison to clonidine had acceptable sedation and hemodynamic stability and minimal dose requirement make very effective adjuvant

  15. Effect of laser phototherapy on human alveolar bone repair: micro tomographic and histomorphometrical analysis

    NASA Astrophysics Data System (ADS)

    Romão, Marcia M. A.; Marques, Márcia M.; Cortes, Arthur R. G.; Horliana, Anna C. R. T.; Moreira, Maria S.; Lascala, Cesar A.

    2015-06-01

    The immediate dental implant placement in the molars region is critical, because of the high amount of bone loss and the discrepancy between the alveolar crest thickness and the dental implant platform. Laser phototherapy (LPT) improves bone repair thus could accelerate the implant placement. Twenty patients were selected for the study. Ten patients were submitted to LPT with GaAlAs diode laser (808nm) during molar extraction, immediately after, 24h, 48h, 72h, 96h and 7 days. The irradiations were applied in contact and punctual mode (100mW, 0.04cm2, 0.75J/cm2, 30s per point, 3J per point). The control group (n=10) received the same treatment; however with the power of the laser off. Forty days later samples of the tissue formed inside the sockets were obtained for further microtomography (microCTs) and histomorphometry analyses. Data were compared by the Student t test, whereas those from the different microCT parameters were compared by the Pearson correlation test (p<0.05). The relative bone volume, as well as area was significantly higher (p<0.001) in the lased than the control group. In the control group there were negative correlations between number and thickness, and between number and separation of trabecula (p<0.01). Between thickness and separation of trabecula the correlation was positive (p<0.01). The laser group showed significant negative correlation between the number and the thickness of trabecula (p<0.01). LPT accelerated bone repair. By the Pearson correlation test it was possible to infer that the lased group presented a more homogeneous trabecular configuration, which would allow earlier dental implant placement.

  16. Radioactivity of natural and artificial building materials - a comparative study.

    PubMed

    Szabó, Zs; Völgyesi, P; Nagy, H É; Szabó, Cs; Kis, Z; Csorba, O

    2013-04-01

    Building materials and their additives contain radioactive isotopes, which can increase both external and internal radioactive exposures of humans. In this study Hungarian natural (adobe) and artificial (brick, concrete, coal slag, coal slag concrete and gas silicate) building materials were examined. We qualified 40 samples based on their radium equivalent, activity concentration, external hazard and internal hazard indices and the determined threshold values of these parameters. Absorbed dose rate and annual effective dose for inhabitants living in buildings made of these building materials were also evaluated. The calculations are based on (226)Ra, (232)Th and (40)K activity concentrations determined by gamma-ray spectrometry. Measured radionuclide concentrations and hence, calculated indices and doses of artificial building materials show a rather disparate distribution compared to adobes. The studied coal slag samples among the artificial building materials have elevated (226)Ra content. Natural, i.e. adobe and also brick samples contain higher amount of (40)K compared to other artificial building materials. Correlation coefficients among radionuclide concentrations are consistent with the values in the literature and connected to the natural geochemical behavior of U, Th and K elements. Seven samples (coal slag and coal slag concrete) exceed any of the threshold values of the calculated hazard indices, however only three of them are considered to be risky to use according to the fact that the building material was used in bulk amount or in restricted usage. It is shown, that using different indices can lead to different conclusions; hence we recommend considering more of the indices at the same time when building materials are studied. Additionally, adding two times their statistical uncertainties to their values before comparing to thresholds should be considered for providing a more conservative qualification. We have defined radon hazard portion to point

  17. Comparative study of Waste Isolation Pilot Plant (WIPP) transportation alternatives

    SciTech Connect

    Not Available

    1994-02-01

    WIPP transportation studies in the Final Supplement Environmental Impact Statement for WIPP are the baseline for this report. In an attempt to present the most current analysis, this study incorporates the most relevant data available. The following three transportation options are evaluated for the Disposal Phase, which is assumed to be 20 years: Truck shipments, consisting of a tractor and trailer, with three TRUPACT-IIs or one RH-72B; Regular commercial train shipments consisting of up to three railcars carrying up to 18 TRUPACT-IIs or up to six RH-72Bs; Dedicated train shipments consisting of a locomotive, an idle car, railcars carrying 18 TRUPACT-IIs or six RH-72Bs, another idle car, and a caboose or passenger car with an emergency response specialist. No other cargo is carried. This report includes: A consideration of occupational and public risks and exposures, and other environmental impacts; A consideration of emergency response capabilities; and An extimation of comparative costs.

  18. Visual Encodings of Temporal Uncertainty: A Comparative User Study.

    PubMed

    Gschwandtnei, Theresia; Bögl, Markus; Federico, Paolo; Miksch, Silvia

    2016-01-01

    A number of studies have investigated different ways of visualizing uncertainty. However, in the temporal dimension, it is still an open question how to best represent uncertainty, since the special characteristics of time require special visual encodings and may provoke different interpretations. Thus, we have conducted a comprehensive study comparing alternative visual encodings of intervals with uncertain start and end times: gradient plots, violin plots, accumulated probability plots, error bars, centered error bars, and ambiguation. Our results reveal significant differences in error rates and completion time for these different visualization types and different tasks. We recommend using ambiguation - using a lighter color value to represent uncertain regions - or error bars for judging durations and temporal bounds, and gradient plots - using fading color or transparency - for judging probability values. PMID:26529717

  19. A Comparative Study of Different Deblurring Methods Using Filters

    NASA Astrophysics Data System (ADS)

    Srimani, P. K.; Kavitha, S.

    2011-12-01

    This paper attempts to undertake the study of Restored Gaussian Blurred Images by using four types of techniques of deblurring image viz., Wiener filter, Regularized filter, Lucy Richardson deconvolution algorithm and Blind deconvolution algorithm with an information of the Point Spread Function (PSF) corrupted blurred image. The same is applied to the scanned image of seven months baby in the womb and they are compared with one another, so as to choose the best technique for restored or deblurring image. This paper also attempts to undertake the study of restored blurred image using Regualr Filter(RF) with no information about the Point Spread Function (PSF) by using the same four techniques after executing the guess of the PSF. The number of iterations and the weight threshold of it to choose the best guesses for restored or deblurring image of these techniques are determined.

  20. Teenage pregnancy: a comparative study of the outcome and complications.

    PubMed

    Thekkekkara, Tina; Veenu, J

    2009-01-01

    This study compares the outcome and complications of pregnancy among teenagers with those above 19 years of age. This retrospective study conducted in a maternity hospital in rural Karnataka, under the guidance of the department of community medicine, St Johns National Academy of Health Sciences, Bangalore, included 221 women who delivered between February 2003 and April 2003. The data was tabulated in excel spreadsheet and analysed using epi 6 programme. Anaemia among teenage multigravidae was found to be a significant health problem. There were no statistically significant differences between the gestational age at delivery and the mode of delivery in the different age groups. Teenage pregnancy was not found to be associated with an increased risk for antenatal complications or postnatal complications. There was no increased incidence of low birth weight or congenital anomalies among the babies of teenage mothers. Mortality was not found to be increased both among the teenage mothers as well as their babies. PMID:19588686

  1. Professional navigation: a comparative study of two Canadian models.

    PubMed

    Fillion, Lise; Cook, Sandra; Veillette, Anne-Marie; de Serres, Marie; Aubin, Michèle; Rainville, François; Fitch, Margaret; Doll, Richard

    2012-01-01

    For many cancer control programs, cancer navigation has emerged as a specific strategy to improve access to supportive care and the patients' experience of cancer care. This study contributes to a better understanding of professional navigation by comparing two Canadian models: Quebec's Pivot Nurse in Oncology (PNO) and Nova Scotia's Cancer Patient Navigator (CPN). Qualitative interviews were conducted with professional navigators, patients and family members, front-line staff, physicians and health administrators (interviews: n = 49; focus groups: n = 10). The two models were analyzed using the professional navigation framework (Fillion et al., 2012). Although the models are different, results show that professional navigators in both programs perform similar functions and face similar challenges. This study highlights the complexity and the value of cancer navigation and recommends relevant actions to optimize its management within the health care system. PMID:23362659

  2. A Comparative Study on Automotive Brake Testing Standards

    NASA Astrophysics Data System (ADS)

    Kumbhar, Bhau Kashinath; Patil, Satyajit Ramchandra; Sawant, Suresh Maruti

    2016-06-01

    Performance testing of automotive brakes involves determination of stopping time, distance and deceleration level. Braking performance of an automobile is required to be ensured for various surfaces like dry, wet, concrete, bitumen etc. as well as for prolonged applications. Various brake testing standards are used worldwide to assure vehicle and pedestrian safety. This article presents methodologies used for automotive service brake testing for two wheelers. The main contribution of this work lies in comparative study of three main brake testing standards; viz. Indian Standards, Federal Motor Vehicle Safety Standards and European Economic Commission Standards. This study shall help the policy makers to choose the best criteria out of these three while formulating newer edition of testing standards.

  3. Metabolic syndrome in patients with psoriasis: A comparative study

    PubMed Central

    Lakshmi, Sristi; Nath, Amiya Kumar; Udayashankar, Carounanidy

    2014-01-01

    Background: Psoriasis patients are at increased risk of developing the metabolic syndrome (MS). Proinflammatory cytokines such as tumor necrosis factor-α, interleukin-6 that are increased in the psoriatic plaques are known to contribute to features of MS such as hypertension, dyslipidemia and insulin resistance. Aims: (1) To establish the frequency of MS in patients with psoriasis. (2) To study the risk factors associated with MS in psoriasis. Materials and Methods: A hospital based comparative study was conducted involving 40 adult patients with psoriasis and 40 age- and sex-matched controls. All participants were evaluated for components of MS. Results: Both groups included 31 males and 9 females. The mean age of the cases and controls were 49.95 years and 49.35 years, respectively. Psoriasis patients with MS had a statistically significant higher mean age (56.31 ± 11.36 years) compared with those without MS (46.89 ± 11.51 years). MS was present in 13 out of 40 (32.5%) patients with psoriasis and 12 out of 40 (30%) controls; this difference was not statistically significant. Higher age and female gender correlated with the presence of MS in psoriasis patients. The presence of MS in psoriasis patients was statistically independent of psoriasis area severity index score, body surface area involvement or psoriatic arthropathy. Conclusion: Our results suggest that there is no close correlation between psoriasis and MS in South Indian patients. PMID:24860744

  4. A comparative study of Raman enhancement in capillaries

    NASA Astrophysics Data System (ADS)

    Eftekhari, Fatemeh; Irizar, Juan; Hulbert, Laila; Helmy, Amr S.

    2011-06-01

    This work reports on the comparative studies of Raman enhancement in liquid core waveguides (LCWs). The theoretical considerations that describe Raman enhancement in LCWs is adapted to analyze and compare the performance of hollow core photonic crystal fibers (HCPCFs) to conventional Teflon capillary tubes. The optical losses in both platforms are measured and used to predict their performance for different lengths. The results show that for an optimal waveguide length, two orders of magnitude enhancement in the Raman signal can be achieved for aqueous solutions using HCPCFs. This length, however, cannot be achieved using normal capillary effects. By integrating the interface of the fluidic pump and the HCPCF into a microfluidic chip, we are able to control fluid transport and fill longer lengths of HCPCFs regardless of the viscosity of the sample. The long-term stability and reproducibility of Raman spectra attained through this platform are demonstrated for naphthalenethiol, which is a well-studied organic compound. Using the HCPCF platform, the detection limit of normal Raman scattering in the range of micro-molars has been achieved. In addition to the higher signal-to-noise ratio of the Raman signal from the HCPCF-platform, more Raman modes of naphthalenethiol are revealed using this platform.

  5. A comparative Study of Circulation Patterns at Active Lava Lakes

    NASA Astrophysics Data System (ADS)

    Lev, Einat; Oppenheimer, Clive; Spampinato, Letizia; Hernandez, Pedro; Unglert, Kathi

    2016-04-01

    Lava lakes present a rare opportunity to study magma dynamics in a large scaled-up "crucible" and provide a unique natural laboratory to ground-truth dynamic models of magma circulation. The persistence of lava lakes allows for long-term observations of flow dynamics and of lava properties, especially compared to surface lava flows. There are currently five persistent lava lakes in the world: Halemaumau in Kilauea (Hawaii, USA), Erta Ale (Ethiopia), Nyiragongo (Congo), Erebus (Antarctica), and Villarica (Chile). Marum and Benbow craters of Ambrym volcano (Vanuatu) and Masaya (Nicaragua) have often hosted lava lakes as well. We use visible-light and thermal infrared time-lapse and video footage collected at all above lakes (except Villarica, where the lake is difficult to observe), and compare the circulation patterns recorded. We calculate lake surface motion from the footage using the optical flow method (Lev et al., 2012) to produce 2D velocity fields. We mined both the surface temperature field and the surface velocity field for patterns using machine learning techniques such as "self-organizing maps (SOMs)" and "principle component analysis (PCA)". We use automatic detection technique to study the configuration of crustal plates at the lakes' surface. We find striking differences among the lakes, in flow direction, flow speed, frequency of changes in flow direction and speed, location and consistency of upwelling and downwelling, and crustal plate configuration. We relate the differences to lake size, shallow conduit geometry, lava viscosity, crystal and gas content, and crust integrity.

  6. Prevalence of Lebanese stroke survivors: A comparative pilot study.

    PubMed

    Lahoud, Nathalie; Salameh, Pascale; Saleh, Nadine; Hosseini, Hassan

    2016-09-01

    Stroke is a leading cause of morbidity and mortality worldwide and its late burden has mainly been attributable to developing countries. Lebanon is one of these countries where epidemiological studies on stroke burden are scarce but necessary. Thus, the present study was conducted to assess the prevalence of stroke survivors among Lebanese inhabitants. A cross-sectional survey was carried out using randomly selected landline phone numbers on all governorates to retrieve data on stroke survivors and their sociodemographic characteristics. Results were then standardized over the Lebanese and the World Health Organization (WHO) world populations. A total of 6963 Lebanese inhabitants were included in the study; among these were 56 stroke survivors. This led to an adjusted stroke prevalence of 0.50% [95% confidence interval (CI)=0.33-0.66%] and a world-standardized prevalence of 0.60% (95% CI=0.42-0.78%). A significantly higher stroke prevalence was found among older age groups and more socioeconomically privileged areas. Overall, the study showed a relatively higher prevalence of stroke in this sample of Lebanese inhabitants when compared to other developing countries. However, larger community-based studies with a clinical assessment of stroke cases are needed to confirm our findings. PMID:26599284

  7. Comparative study on the biodegradability of morpholinium herbicidal ionic liquids.

    PubMed

    Ławniczak, Łukasz; Materna, Katarzyna; Framski, Grzegorz; Szulc, Alicja; Syguda, Anna

    2015-07-01

    This study focused on evaluating the toxicity as well as primary and ultimate biodegradability of morpholinium herbicidal ionic liquids (HILs), which incorporated MCPA, MCPP, 2,4-D or Dicamba anions. The studied HILs were also subjected to determination of surface active properties in order to assess their influence on toxicity and biodegradability. The study was carried out with microbiota isolated from different environmental niches: sediments from river channel, garden soil, drainage trench collecting agricultural runoff stream, agricultural soil and municipal waste repository. The obtained results revealed that resistance to toxicity and biodegradation efficiency of the microbiota increased in the following order: microbiota from the waste repository > microbiota from agricultural soil ≈ microbiota from an agricultural runoff stream > microbiota from garden soil > microbiota from the river sludge. It was observed that the toxicity of HILs increased with the hydrophobicity of the cation, however the influence of the anion was more notable. The highest toxicity was observed when MCPA was used as the anion (EC50 values ranging from 60 to 190 mg L(-1)). The results of ultimate biodegradation tests indicated that only HILs with 2,4-D as the anion were mineralized to some extent, with slightly higher values for HILs with the 4-decyl-4-ethylmorpholinium cation (10-31 %) compared to HILs with the 4,4-didecylmorpholinium cation (9-20 %). Overall, the cations were more susceptible (41-94 %) to primary biodegradation compared to anions (0-61 %). The obtained results suggested that the surface active properties of the studied HILs may influence their toxicity and biodegradability by bacteria in different environmental niches. PMID:26099357

  8. Comparative Study of Algorithms for Automated Generalization of Linear Objects

    NASA Astrophysics Data System (ADS)

    Azimjon, S.; Gupta, P. K.; Sukhmani, R. S. G. S.

    2014-11-01

    Automated generalization, rooted from conventional cartography, has become an increasing concern in both geographic information system (GIS) and mapping fields. All geographic phenomenon and the processes are bound to the scale, as it is impossible for human being to observe the Earth and the processes in it without decreasing its scale. To get optimal results, cartographers and map-making agencies develop set of rules and constraints, however these rules are under consideration and topic for many researches up until recent days. Reducing map generating time and giving objectivity is possible by developing automated map generalization algorithms (McMaster and Shea, 1988). Modification of the scale traditionally is a manual process, which requires knowledge of the expert cartographer, and it depends on the experience of the user, which makes the process very subjective as every user may generate different map with same requirements. However, automating generalization based on the cartographic rules and constrains can give consistent result. Also, developing automated system for map generation is the demand of this rapid changing world. The research that we have conveyed considers only generalization of the roads, as it is one of the indispensable parts of a map. Dehradun city, Uttarakhand state of India was selected as a study area. The study carried out comparative study of the generalization software sets, operations and algorithms available currently, also considers advantages and drawbacks of the existing software used worldwide. Research concludes with the development of road network generalization tool and with the final generalized road map of the study area, which explores the use of open source python programming language and attempts to compare different road network generalization algorithms. Thus, the paper discusses the alternative solutions for automated generalization of linear objects using GIS-technologies. Research made on automated of road network

  9. Comparative study of visual pathways in owls (Aves: Strigiformes).

    PubMed

    Gutiérrez-Ibáñez, Cristián; Iwaniuk, Andrew N; Lisney, Thomas J; Wylie, Douglas R

    2013-01-01

    Although they are usually regarded as nocturnal, owls exhibit a wide range of activity patterns, from strictly nocturnal, to crepuscular or cathemeral, to diurnal. Several studies have shown that these differences in the activity pattern are reflected in differences in eye morphology and retinal organization. Despite the evidence that differences in activity pattern among owl species are reflected in the peripheral visual system, there has been no attempt to correlate these differences with changes in the visual regions in the brain. In this study, we compare the relative size of nuclei in the main visual pathways in nine species of owl that exhibit a wide range of activity patterns. We found marked differences in the relative size of all visual structures among the species studied, both in the tectofugal and the thalamofugal pathway, as well in other retinorecipient nuclei, including the nucleus lentiformis mesencephali, the nucleus of the basal optic root and the nucleus geniculatus lateralis, pars ventralis. We show that the barn owl (Tyto alba), a species widely used in the study of the integration of visual and auditory processing, has reduced visual pathways compared to strigid owls. Our results also suggest there could be a trade-off between the relative size of visual pathways and auditory pathways, similar to that reported in mammals. Finally, our results show that although there is no relationship between activity pattern and the relative size of either the tectofugal or the thalamofugal pathway, there is a positive correlation between the relative size of both visual pathways and the relative number of cells in the retinal ganglion layer. PMID:23296024

  10. Alcoholic Steatosis in Different Strains of Rat: A Comparative Study

    PubMed Central

    Bhopale, Kamlesh K.; Kondraganti, Shakuntala; Fernando, Harshica; Boor, Paul J.; Kaphalia, Bhupendra S.; Shakeel Ansari, G. A.

    2016-01-01

    Background Different strains of rats have been used to study alcoholic liver disease (ALD) while the reason for selecting a particular rat strain was not apparent. Purpose The aim of our study was to compare outbred (Wistar) and inbred (Fischer) strains to evaluate pathological, biochemical changes, and gene expression differences associated with ethanol-induced early hepatic steatosis. Study Design Male Wistar and Fischer-344 rats were pair-fed for 6 weeks with or without 5% ethanol in Lieber-DeCarli liquid diet. Livers were analyzed for histological and lipid-related differences. Results Hepatic midzonal steatosis was mainly found in Wistar rats while Fischer rats showed mostly pericentral steatosis. Increased hepatic steatosis in ethanol-fed Wistar rats is supported by increases in lipids with related genes and transcription factors involved in fatty acid and triglyceride synthesis. Conclusion Our data showed that Fischer rats are relatively less prone to ethanol-mediated steatosis with pericentral lipid deposition pattern in the liver which is similar to humans and show no trace level of lipid accumulation in pair-fed controls as observed in Wistar (outbred) strain. Therefore, Fischer rats are better suited for lipid studies in an early development of ALD. PMID:27213081

  11. Comparative study of PCA in classification of multichannel EMG signals.

    PubMed

    Geethanjali, P

    2015-06-01

    Electromyographic (EMG) signals are abundantly used in the field of rehabilitation engineering in controlling the prosthetic device and significantly essential to find fast and accurate EMG pattern recognition system, to avoid intrusive delay. The main objective of this paper is to study the influence of Principal component analysis (PCA), a transformation technique, in pattern recognition of six hand movements using four channel surface EMG signals from ten healthy subjects. For this reason, time domain (TD) statistical as well as auto regression (AR) coefficients are extracted from the four channel EMG signals. The extracted statistical features as well as AR coefficients are transformed using PCA to 25, 50 and 75 % of corresponding original feature vector space. The classification accuracy of PCA transformed and non-PCA transformed TD statistical features as well as AR coefficients are studied with simple logistic regression (SLR), decision tree (DT) with J48 algorithm, logistic model tree (LMT), k nearest neighbor (kNN) and neural network (NN) classifiers in the identification of six different movements. The Kruskal-Wallis (KW) statistical test shows that there is a significant reduction (P < 0.05) in classification accuracy with PCA transformed features compared to non-PCA transformed features. SLR with non-PCA transformed time domain (TD) statistical features performs better in accuracy and computational power compared to other features considered in this study. In addition, the motion control of three drives for six movements of the hand is implemented with SLR using TD statistical features in off-line with TMSLF2407 digital signal controller (DSC). PMID:25860845

  12. Comparative micromorphological study of wild and micropropagated Dioscorea bulbifera Linn.

    PubMed Central

    Sonibare, Mubo A.; Adeniran, Adedapo A.

    2014-01-01

    Objective To study the leaf epidermis of wild and micropropagated Dioscorea bulbifera Linn. (D. bulbifera) in order to document useful diagnostic features that may be employed for correct crude drug identification and to clear any taxonomic uncertainties in the micropropagated medicinal plant. Methods Growth responses of micropropagated D. bulbifera were observed on Murashige Skoog medium supplemented with 6-benzylamino purine (1.0 mg/L)+α-naphthaleneacetic acid (0.2 mg/L)+cysteine (20 mg/L) using nodal segments as explants. Leaves of the wild and micropropagated plants were studied microscopically. Results More than 80% shoot regeneration and formation of 10%-30% whitish-brown callus were observed within 3 weeks. The highest root proliferation was obtained from Murashige Skoog medium of 6-benzylamino purine (0.05 mg/L) and α-naphthaleneacetic acid (0.01 mg/L) with mean root length of (27.00±1.25) mm and elongated single shoot of mean length (38.00±11.09) mm. Leaf epidermal features that revealed similarities between the wild and micropropagated plants included amphistomatic condition, presence of mucilage, glandular unicellular trichome with multicellular head, polygonal cells with smooth walls, stomata type and shape. Slight variations included thick cuticular wall with closed stomata in wild plant compared to thin walled opened stomata in the in vitro plant. Opening of stomata accounted for larger average stomata sizes of (7.68±0.38) µm and (6.14±0.46) µm on the adaxial and abaxial surfaces, respectively of the micropropagated plant compared to the wild. Conclusions The diagnostic features obtained in the study could serve as a basis for proper identification for quality control for standardization of the medicinal plant. PMID:25182434

  13. Antiamoebic chemoprophylaxis using quinfamide in children: a comparative study.

    PubMed

    Padilla, Nicolas; Diaz, Rosalinda; Alarcon, Alfonso; Barreda, Roberto

    2002-04-20

    This study sought to examine whether the administration of quinfamide at 3- or 6-month intervals diminished the frequency of Entamoeba histolytica cysts in stool samples compared to controls. The prospective, longitudinal, randomized, single-blind study examined children from six primary schools in Celaya and Neutla, Guanajuato. Of the 1,524 students in these schools, we selected participants for the study as follows: Children were included in the study if their parents agreed in writing to the study and if the children demonstrated evidence of E. histolytica cysts after a parasitoscopic analysis by concentration (PSC) in three samples over consecutive days using Faust"s method. Those included in the study received a single 4.3-g/kg dose of quinfamide, and we performed PSC on days 5, 6, and 7 following dose administration to examine whether quinfamide had affected the presence of the cysts. The study participants who tested negative for cysts were divided into three groups: Group 1 had 102 patients who underwent quinfamide treatment and three CPS analyses after the 12 months of the study; Group 2 had 98 subjects who underwent the quinfamide treatment and three CPS analyses at months 3, 6, 9, and 12 after their entrance into the study; and Group 3 had 102 patients, who underwent the quinfamide treatment and series of three CPS analyses at months 6 and 12 of the study. All participants received the dose of quinfamide after providing stool samples and after a clinical gastrointestinal history was obtained. Further clinical gastrointestinal data were collected 5 days after the quintamide dose was administered. We used EpiInfo 6.0 for statistical analysis, calculating c2 and p values for the clinical data and the CPS data after the 12 months concluded. Of the initial samples of 1,524 subjects, 308 (20.2%) had Entamoebic cysts. Of these, six were further eliminated because they did not meet the inclusion requirements. At the conclusion of the study, Group 1 presented

  14. Biomechanical and histomorphometric colon remodelling in STZ-induced diabetic rats.

    PubMed

    Zhao, Jingbo; Nakaguchi, Toshiya; Gregersen, Hans

    2009-08-01

    The histomorphologic and passive biomechanical properties were studied in the mid-colon of 16 non-diabetic and 20 streptozotocin (STZ)-induced diabetic rats (50 mg/kg STZ, ip). The diabetic rats were divided into groups living 4 and 8 weeks after the induction of diabetes (n = 10 for each group). The mechanical test was a ramp distension of fluid into the colon in vitro. The colon diameter and length were obtained from digitized images of the segments at pre-selected pressures and at the no-load and zero-stress states. Circumferential and longitudinal stresses and strains were computed from the length, diameter, and pressure data and from the zero-stress state geometry. The blood glucose level increased 3-4-fold in the diabetic rats compared with the controls (P < 0.001). Diabetes generated pronounced increases in the colon weight per length, wall thickness, and wall cross-sectional area (P < 0.001). Histologically, the thickness of all layers was increased during diabetes (P < 0.05), especially the mucosa layer. The opening angle, and absolute values of residual strain increased in the diabetic group (P < 0.05 and P < 0.01, respectively). Furthermore, diabetes increased the circumferential and longitudinal stiffness of the colon wall (P < 0.001). The observed changes in residual strain, opening angle, and stress-strain relation may be contributing factors to colonic dysfunction and abdominal pain in diabetic patients. PMID:18989775

  15. Contrasting tropical estuarine ecosystem functioning and stability: A comparative study

    NASA Astrophysics Data System (ADS)

    Villanueva, Maria Ching

    2015-03-01

    A comparative study of the Sine-saloum (Senegal) and Gambia (The Gambia) estuaries was performed based on trophic model outputs that describe the system structure and functioning. These trophic models were constructed such as to differentiate main energetic flows in the systems and express how climate change may have impacted ecosystem resilience to change. Estuarine fish assemblages are highly resilient despite exposure to vast hydrodynamic variations and stress. Coupled with strong anthropogenic-driven stresses such as fisheries and climate change, ecosystems may undergo severe regime shifts that may weaken their resilience and stability. Taxonomically related and morphologically similar species do not necessarily play similar ecological roles in these two ecosystems. Biomass and production in the Sine-saloum are concentrated at trophic levels (TLs) 2 and 3, while for the Gambia, both are concentrated at TL3. Higher TL biomasses in Gambia compared to Sine-Saloum may be explained by the latter ecosystem being characterized by inverse hypersalinity. Higher TL of production in Sine-Saloum is due to higher exploitations compared to Gambia where fishing activities are still less developed. High production and consumption rates of some groups in both ecosystems indicate high system productivity. Elevated productivity may be due to higher abundance of juvenile fishes in most groups that utilize the latter as refuge and/or nursery zones. Both ecosystems are phytoplankton-driven. Differences in group trophic and ecological roles are mainly due to adaptive responses of these species to seasonal and long-term climate and anthropogenic stressors. System indicators suggest different levels of ecosystem resilience and stability as a function of biodiversity. Relevance of other observations on ecosystem functioning and indicators in relation to perturbation is discussed.

  16. Colloidal dispersions for the delivery of acyclovir: a comparative study.

    PubMed

    Cortesi, Rita; Ravani, Laura; Menegatti, Enea; Drechsler, M; Esposito, Elisabetta

    2011-11-01

    This paper describes a comparative study on the performances of ethosomes and solid lipid nanoparticle as delivery systems for acyclovir. Ethosomes were spontaneously produced by dissolution of phosphatidylcholine and acyclovir in ethanol followed by addition of an aqueous buffer while solid lipid nanoparticle were produced by homogenization and ultrasonication. Both colloidal systems were morphologically characterized by cryo-transmission electron microscopy. The encapsulation efficiency was 94.2±2.8% for ethosomes and 53.2±0.2% for solid lipid nanoparticle. Concerning Z potential, both formulations are close to neutrality. The diffusion coefficients of the drug from ethosomes and solid lipid nanoparticle, determined by a Franz cell method, were 9.4 and 1.2-fold lower as compared to the free acyclovir in solution, thus evidencing the ability of both colloidal systems in enhancing the diffusion of the drug. The antiviral activity against HSV-1 of both systems was tested by plaque reduction assay in monolayer cultures of Vero cells. Data showed that no significant differences in the antiviral activity were observed by acyclovir in the free or loaded forms. Taken together these results, colloidal systems could be interesting to mediate the penetration of acyclovir within Vero cells. PMID:23112407

  17. Comparative Study of Naugle and Hertel Exophthalmometry in Orbitozygomatic Fracture.

    PubMed

    Jeon, Hong Bae; Kang, Dong Hee; Oh, Sang Ah; Gu, Ja Hea

    2016-01-01

    Accurate perioperative evaluation of enophthalmos is important to determine the adequacy of surgical repair in orbitozygomatic fracture. In this study, the authors evaluated the degree of enophthalmos using Hertel and Naugle exophthalmometry in patients with pure blowout fracture and orbitozygomatic fracture, and compared the results. Fifty patients were divided into 2 groups: pure blowout fracture (Group A: control group, 25 patients) and orbitozygomatic fracture with displaced lateral orbital rim (Group B: experimental group, 25 patients). Hertel and Naugle scales were measured before and 6 months after surgery. The degree of lateral orbital rim advancement was assessed by comparing the difference between the perioperative change of the Hertel and Naugle scales. In Group A, the difference between the pre- and postoperative scales in the 2 exophthalmometry was statistically significant (P < 0.05). In Group B, the Hertel scale increased from -0.20 to -0.16 mm, with an insignificant difference between pre- and postoperative values (P > 0.05) and the Naugle scale increased from -0.88 to -0.20 mm, with a significant difference (P < 0.05). The Δ Hertel scale differed from the Δ Naugle scale by a mean of -0.64 mm, which represents the degree of lateral orbital rim advancement. Naugle exophthalmometry is a more reliable method for evaluation of enophthalmos in lateral orbital rim displaced orbitozygomatic fractures than Hertel exophthalmometry. The degree of lateral orbital rim advancement can be assessed by combined use of the Hertel and Naugle exophthalmometry in orbitozygomatic fractures. PMID:26674913

  18. Lead exposure among five distinct occupational groups: a comparative study.

    PubMed

    Gharaibeh, Mohammad Younis; Alzoubi, Karem Hasan; Khabour, Omar Falah; Khader, Yousef Saleh; Gharaibeh, Mamoun Abdallah; Matarneh, Sulaiman Khalid

    2014-01-01

    This study was conducted to evaluate blood lead concentration among five selected occupational groups. The five groups were: hospital health workers, shop workers, taxi drivers, automobiles mechanics, and wood workers. The groups did not significantly differ among each other in the average of age and work years. ANOVA test revealed significantly higher mean lead blood concentration in taxi drivers, automechanics, and wood workers compared to other groups. Additionally, workers with lead concentration >0.483 umol/L (10μg/dL) were more likely to have frequent muscle pain compared to those with lower concentrations. No association between other symptoms of lead exposure/toxicity and blood lead concentration was detected. In conclusion, special attention must be directed toward lead blood levels and lead poisoning symptoms when examining patients from certain occupational groups such as taxi drivers, automechanics, and wood workers. Special safety precautions and educational programs are also needed to limit the lead exposure in these occupational groups. PMID:24374433

  19. Evolutionary algorithms, simulated annealing, and Tabu search: a comparative study

    NASA Astrophysics Data System (ADS)

    Youssef, Habib; Sait, Sadiq M.; Adiche, Hakim

    1998-10-01

    Evolutionary algorithms, simulated annealing (SA), and Tabu Search (TS) are general iterative algorithms for combinatorial optimization. The term evolutionary algorithm is used to refer to any probabilistic algorithm whose design is inspired by evolutionary mechanisms found in biological species. Most widely known algorithms of this category are Genetic Algorithms (GA). GA, SA, and TS have been found to be very effective and robust in solving numerous problems from a wide range of application domains.Furthermore, they are even suitable for ill-posed problems where some of the parameters are not known before hand. These properties are lacking in all traditional optimization techniques. In this paper we perform a comparative study among GA, SA, and TS. These algorithms have many similarities, but they also possess distinctive features, mainly in their strategies for searching the solution state space. the three heuristics are applied on the same optimization problem and compared with respect to (1) quality of the best solution identified by each heuristic, (2) progress of the search from initial solution(s) until stopping criteria are met, (3) the progress of the cost of the best solution as a function of time, and (4) the number of solutions found at successive intervals of the cost function. The benchmark problem was is the floorplanning of very large scale integrated circuits. This is a hard multi-criteria optimization problem. Fuzzy logic is used to combine all objective criteria into a single fuzzy evaluation function, which is then used to rate competing solutions.

  20. Early parenting styles and sexual offending behavior: A comparative study.

    PubMed

    Sigre-Leirós, Vera; Carvalho, Joana; Nobre, Pedro J

    2016-01-01

    Sexual offenders, in general, report problematic rearing practices from their parents, lacking however more empirical research on this topic regarding particular subtypes of offenders. The current study examined the relationship between early parenting styles and different types of sexual offending. A total of 113 sexual offenders (rapists, pedophilic and nonpedophilic child molesters), and 51 nonsexual offenders completed the EMBU (My Memories of Upbringing), the Brief Symptom Inventory, and the Socially Desirable Response Set Measure. Results showed that rapists were less likely to remember their fathers as being emotionally warm compared with nonsexual offenders and pedophilic child molesters. In addition, compared with rapists, pedophilic offenders perceived their mothers as having been less emotionally warm to them. Overall, results showed that certain developmental experiences with parents were able to distinguish between subtypes of offenders supporting an association between distal interpersonal factors and sexual offending. These findings may have important implications for early intervention and prevention of sexual crimes. Further research using larger samples of pedophilic child molesters is recommended. PMID:27019974

  1. Colloidal Dispersions for the Delivery of Acyclovir: A Comparative Study

    PubMed Central

    Cortesi, Rita; Ravani, Laura; Menegatti, Enea; Drechsler, M.; Esposito, Elisabetta

    2011-01-01

    This paper describes a comparative study on the performances of ethosomes and solid lipid nanoparticle as delivery systems for acyclovir. Ethosomes were spontaneously produced by dissolution of phosphatidylcholine and acyclovir in ethanol followed by addition of an aqueous buffer while solid lipid nanoparticle were produced by homogenization and ultrasonication. Both colloidal systems were morphologically characterized by cryo-transmission electron microscopy. The encapsulation efficiency was 94.2±2.8% for ethosomes and 53.2±0.2% for solid lipid nanoparticle. Concerning Z potential, both formulations are close to neutrality. The diffusion coefficients of the drug from ethosomes and solid lipid nanoparticle, determined by a Franz cell method, were 9.4 and 1.2-fold lower as compared to the free acyclovir in solution, thus evidencing the ability of both colloidal systems in enhancing the diffusion of the drug. The antiviral activity against HSV-1 of both systems was tested by plaque reduction assay in monolayer cultures of Vero cells. Data showed that no significant differences in the antiviral activity were observed by acyclovir in the free or loaded forms. Taken together these results, colloidal systems could be interesting to mediate the penetration of acyclovir within Vero cells. PMID:23112407

  2. Clobetasone treatment of allergic conjunctivitis: a comparative double blind study.

    PubMed

    Cerqueti, P M; Prosio, P E; Bosia, S; Buscaglia, S; Ciprandi, G

    1993-01-01

    Glucocorticosteroids are often included in the treatment of allergic conjunctivitis. The present study compares the efficacy on clinical and cytological parameters and safety of topical clobetasone butyrate compared to placebo. The trial, designed as double blind, randomized and parallel group treatment, was carried out in 30 patients, suffering from seasonal allergic conjunctivitis due to Grass pollen, during the pollen season (June 1992). Patients received clobetasone butyrate 0.1% eye drops or placebo eye drops, two drops each eye, t.i.d. for 10 days. The clinical and cytological evidences were investigated on admission and at the end of treatment by clinicians and by patients on a dairy card. The steroid group showed a rapid and significant clinical improvement and at the end of the trial a statistically significant difference was evidenced between the active drug treated group and placebo treated group. No serious side effects were observed. The results show the clinical efficacy of clobetasone butyrate in the treatment of pollen-induced allergic conjunctivitis. PMID:8337991

  3. A comparative study of the vibration damping capacity of superalloys

    SciTech Connect

    Wang, J.; Chung, D.D.L.

    1999-10-01

    A comparative study of nickel-base, iron-base, and iron-nickel base superalloys showed Inconel MA754 (oxide dispersion strengthened) to be particularly high in vibration damping capacity. Dynamic mechanical testing was performed using a Perkin-Elmer Corp. (Norwalk, Connecticut) DMA7e instrument under dynamic flexure by three-point bending at a frequency of 0.2 Hz, with a displacement in the range of 5 to 9 {micro}m and a temperature of 475 C. The span in three-point bending was 20 mm. The sample length (in the span direction) was in the range of 20 to 25 mm. The sample width was 6 mm or less, and the sample thickness was in the range of 0.5 to 1.2 mm. The loss tangent, tan {delta}, and storage modulus were measured simultaneously.

  4. [Comparative study of discriminative stimulus properties of antidepressants].

    PubMed

    Korolev, A O; Kalinina, T S; Volkova, A V; Mokrov, G V; Kudriashov, N V; Voronina, T A

    2014-01-01

    Interoceptive stimulus properties of amitriptyline (54 mg/kg body weight), fluoxetine (10 mg/kg), and pyrrolo[1,2-a][1,4]diazepine derivative GMAL-24 (10 mg/kg) were studied in a standard operant model with liquid reinforcement of drug discrimination (DD) in male Wistar rats. A new experimental schedule that includes subchronic (7-day) administration of a training drug was used to perform DD learning. For the first time, it was found that amitriptyline has a discriminative interoceptive stimulus properties. Neither fluoxetine nor GMAL-24 did exhibit interoceptive properties. Imipramine (15 mg/kg, i.p.) fully substitutes for amitriptyline stimulus in substitution test. Fluoxetine (5 - 20 mg/kg, i.p.) failed to substitute with amitriptyline. Thus, amitriptyline/saline drug discrimination should be used for a comparative analysis of the central mechanisms of action of psychotropic substances, rather than for screening specific antidepressant activity. PMID:25322645

  5. A comparative study of two stochastic mode reduction methods

    SciTech Connect

    Stinis, Panagiotis

    2005-09-01

    We present a comparative study of two methods for thereduction of the dimensionality of a system of ordinary differentialequations that exhibits time-scale separation. Both methods lead to areduced system of stochastic differential equations. The novel feature ofthese methods is that they allow the use, in the reduced system, ofhigher order terms in the resolved variables. The first method, proposedby Majda, Timofeyev and Vanden-Eijnden, is based on an asymptoticstrategy developed by Kurtz. The second method is a short-memoryapproximation of the Mori-Zwanzig projection formalism of irreversiblestatistical mechanics, as proposed by Chorin, Hald and Kupferman. Wepresent conditions under which the reduced models arising from the twomethods should have similar predictive ability. We apply the two methodsto test cases that satisfy these conditions. The form of the reducedmodels and the numerical simulations show that the two methods havesimilar predictive ability as expected.

  6. ICD-10 mortality coding and the NCIS: a comparative study.

    PubMed

    Daking, Leanne; Dodds, Leonie

    2007-01-01

    The collection and utilisation of mortality data are often hindered by limited access to contextual details of the circumstances surrounding fatal incidents. The National Coroners Information System (NCIS) can provide researchers with access to such information. The NCIS search capabilities have been enhanced by the inclusion of data supplied by the Australian Bureau of Statistics (ABS), specifically the ICD-10 Cause of Death code set. A comparative study was conducted to identify consistencies and differences between ABS ICD-10 codes and those that could be generated by utilising the full NCIS record. Discrepancies between the two sets of codes were detected in over 50% of cases, which highlighted the importance of access to complete and timely documentation in the assignment of accurate and detailed cause of death codes. PMID:18195402

  7. A comparative study of two different clear aligner systems

    PubMed Central

    2014-01-01

    Background This study aims to compare the ‘Nuvola®’ system with ‘Fantasmino®’ system, examine their material properties, and define the indications for use of the aligners. Methods Two groups of patients were selected and were respectively treated with Nuvola® aligner and Fantasmino® system. Results The goal of treatment has been achieved with the two systems. Conclusions The two types of aligners have shown differences during the treatment. Fantasmino® system has elastic properties of high performance, but its size does not encourage compliance throughout the day. Nuvola® system determines good tooth movement and its size facilitates the patient’s collaboration. In both aligner systems, difficulties were found in the correction of torque information and rotations. PMID:24934094

  8. Magnetic Field Configuration Models and Reconstruction Methods: a comparative study

    NASA Astrophysics Data System (ADS)

    Al-haddad, Nada; Möstl, Christian; Roussev, Ilia; Nieves-Chinchilla, Teresa; Poedts, Stefaan; Hidalgo, Miguel Angel; Marubashi, Katsuhide; Savani, Neel

    2012-07-01

    This study aims to provide a reference to different magnetic field models and reconstruction methods. In order to understand the dissimilarities of those models and codes, we analyze 59 events from the CDAW list, using four different magnetic field models and reconstruction techniques; force- free reconstruction (Lepping et al.(1990); Lynch et al.(2003)), magnetostatic reconstruction, referred as Grad-Shafranov (Hu & Sonnerup(2001); Mostl et al.(2009)), cylinder reconstruction (Marubashi & Lepping(2007)), elliptical, non-force free (Hidalgo et al.(2002)). The resulted parameters of the reconstructions, for the 59 events are compared, statistically, as well as in more details for some cases. The differences between the reconstruction codes are discussed, and suggestions are provided as how to enhance them. Finally we look at 2 unique cases under the microscope, to provide a comprehensive idea of the different aspects of how the fitting codes work.

  9. Anatomopathological findings in scars: comparative study between different specimens.

    PubMed

    Munteanu, Andrada Despina; Bedereag, Ştefan Iulian; NiŢescu, Cristian; Florescu, Ioan Petre

    2015-01-01

    In spite of the remarkable progress science and medicine have experienced, many facts concerning healing processes and pathological scars are still unknown or incompletely explained. This paper is part of a larger study (research for a PhD thesis) concerning new approaches in the prevention and treatment of pathological post-burn scars. We present and analyze the cases of some patients who developed abnormal scars in order to understand and point out the characteristics, that different types of pathological scars have in common and how we can differentiate them. Knowing what issue to address is the key to any successful therapy. Thus, the information we obtained will help us in applying more appropriate and efficient methods of treatment and in our further research: comparing the efficiency of newer therapies to that of older ones. PMID:25826518

  10. A Comparative Study : Microprogrammed Vs Risc Architectures For Symbolic Processing

    NASA Astrophysics Data System (ADS)

    Heudin, J. C.; Metivier, C.; Demigny, D.; Maurin, T.; Zavidovique, B.; Devos, F.

    1987-05-01

    It is oftenclaimed that conventional computers are not well suited for human-like tasks : Vision (Image Processing), Intelligence (Symbolic Processing) ... In the particular case of Artificial Intelligence, dynamic type-checking is one example of basic task that must be improved. The solution implemented in most Lisp work-stations consists in a microprogrammed architecture with a tagged memory. Another way to gain efficiency is to design a well suited instruction set for symbolic processing, which reduces the semantic gap between the high level language and the machine code. In this framework, the RISC concept provides a convenient approach to study new architectures for symbolic processing. This paper compares both approaches and describes our projectof designing a compact symbolic processor for Artificial Intelligence applications.

  11. Advanced general aviation comparative engine/airframe integration study

    NASA Technical Reports Server (NTRS)

    Huggins, G. L.; Ellis, D. R.

    1981-01-01

    The NASA Advanced Aviation Comparative Engine/Airframe Integration Study was initiated to help determine which of four promising concepts for new general aviation engines for the 1990's should be considered for further research funding. The engine concepts included rotary, diesel, spark ignition, and turboprop powerplants; a conventional state-of-the-art piston engine was used as a baseline for the comparison. Computer simulations of the performance of single and twin engine pressurized aircraft designs were used to determine how the various characteristics of each engine interacted in the design process. Comparisons were made of how each engine performed relative to the others when integrated into an airframe and required to fly a transportation mission.

  12. Comparative study of the synthesis of layered transition metal molybdates

    NASA Astrophysics Data System (ADS)

    Mitchell, S.; Gómez-Avilés, A.; Gardner, C.; Jones, W.

    2010-01-01

    Mixed metal oxides (MMOs) prepared by the mild thermal decomposition of layered double hydroxides (LDHs) differ in their reactivity on exposure to aqueous molybdate containing solutions. In this study, we investigate the reactivity of some T-Al containing MMOs ( T=Co, Ni, Cu or Zn) towards the formation of layered transition metal molybdates (LTMs) possessing the general formula AT2(OH)(MoO 4) 2·H 2O, where A=NH 4+, Na + or K +. The phase selectivity of the reaction was studied with respect to the source of molybdate, the ratio of T to Mo and the reaction pH. LTMs were obtained on reaction of Cu-Al and Zn-Al containing MMOs with aqueous solutions of ammonium heptamolybdate. Rehydration of these oxides in the presence of sodium or potassium molybdate yielded a rehydrated LDH phase as the only crystalline product. The LTM products obtained by the rehydration of MMO precursors were compared with LTMs prepared by direct precipitation from the metal salts in order to study the influence of preparative route on their chemical and physical properties. Differences were noted in the composition, morphology and thermal properties of the resulting products.

  13. Biofragmentable bowel anastomosis ring: comparative efficacy studies in dogs.

    PubMed

    Maney, J W; Katz, A R; Li, L K; Pace, W G; Hardy, T G

    1988-01-01

    Three studies were conducted in a total of 178 dogs to determine the efficacy of a biofragmentable bowel anastomosis ring (BAR) composed of polyglycolic acid and 12.5% barium sulfate. Wound strength and healing of BAR, suture, and staple colonic anastomoses were compared for intervals of up to 1 year. The effect of systemic steroid treatment and BAR size on anastomotic wound strength and healing was also studied. The BARs fragmented at a mean time of 15.06 days postoperatively and were passed in the feces without injury. Wound strength was determined by measurements of the pressure required to burst the anastomosed colonic segment and measurements of the tension required to break 10 mm wide longitudinal strips of the anastomosed segment. The studies demonstrated that wound strength had progressed to a point where continued mechanical support (with sutures or staples) was no longer required by 14 days in both nontreated and steroid-treated dogs. Gross healing evaluations at 21 days and beyond showed no differences due to anastomotic method. Microscopic evaluations suggested that residual granulation tissue was less at the sites of BAR asastomoses than at sites of suture or staple anastomoses at the 1-year interval, suggesting that healing may be better with BAR than with standard methods of colon anastomosis. PMID:3336869

  14. Psychological profile of women with infertility: A comparative study

    PubMed Central

    Poddar, Shuvabrata; Sanyal, Nilanjana; Mukherjee, Urbi

    2014-01-01

    Background: An endeavour to probe into the psychological profile of infertile women in a comparative stance with the fertile women is not very common. This study is an attempt to explore the possible non-apparent personality factors which contribute to the unexplained pain of infertility. Methods: The main objectives of the present study were (a) to examine whether infertile women are different from fertile women in terms of selected psychological variables- narcissistic components, dimensions of attachment style and uses of defensive manoeuvres; and (b) whether the primary infertile women (n=18) are different from the secondary infertile women (n=12) with respect to those variables. A total of 60 individuals (30 infertile women and 30 matched fertile women) were assessed through Attachment Style Questionnaire (ASQ), Narcissistic Personality Inventory (NPI) and Defense Style Questionnaire (DSQ-40). General Health Questionnaire (GHQ) was administered on to the fertile women to rule out the psychiatric morbidity. Results: Findings revealed that infertile women group differed from fertile women group with respect to narcissism, dimensions of attachment style and uses of defense mechanism. The primary infertile group also showed marked difference from the secondary infertile group with respect to those variables. Conclusions: This study endeavours to enrich the knowledge regarding the personality dynamics of infertile women to design psychotherapeutic programme to aid their well-being, help them to cherish the flavour of parenthood and improve their quality of life. PMID:25788801

  15. The comparative study of solvents to expedite removal of bitumen.

    PubMed

    Iuchi, Manabu; Sugiyama, Masahide; Oyatsu, Yasuyuki; Fukai, Takao

    2009-03-01

    Hot-bitumen burn is a unique case in all types of burns. This melting substance is difficult to remove when it adheres to the skin and solidifies. It causes burns and sticks to the skin when it is cooled to the skin temperature. Some reports are available on many kinds of solvents for the removal of solid bitumen. However, there have thus far been no comparative studies. It is necessary to seek for an optimum method to remove bitumen without consuming so much time and with minimum injury to the skin. The selected solvents in this study were petrolatum, olive oil, salad oil, butter, Neosporin ointment and De-solv-it. They were often reported as being effective for hot-bitumen burn injuries with little irritation for a damaged skin. It is easy to purchase them commercially. Each solvent was poured over the bitumen in a test tube. Afterwards, the concentrations of the bitumen in the solvents were quantified with the fluorescence measurement technique. We consider De-solv-it is the one of the best solvent for the removal of bitumen and highly recommended for hot-bitumen burns. The results of this study suggest that dressing change should be done every 4 to 8 h or as frequently as needed until the bitumen is entirely removed. PMID:18789588

  16. Institutions and national development in Latin America: a comparative study

    PubMed Central

    Portes, Alejandro; Smith, Lori D.

    2013-01-01

    We review the theoretical and empirical literatures on the role of institutions on national development as a prelude to present a more rigorous and measurable definition of the concept and a methodology to study this relationship at the national and subnational levels. The existing research literature features conflicting definitions of the concept of “institutions” and empirical tests based mostly on reputational indices, with countries as units of analysis. The present study’s methodology is based on a set of five strategic organizations studied comparatively in five Latin American countries. These include key federal agencies, public administrative organizations, and stock exchanges. Systematic analysis of results show a pattern of differences between economically-oriented institutions and those entrusted with providing basic services to the general population. Consistent differences in institutional quality also emerge across countries, despite similar levels of economic development. Using the algebraic methods developed by Ragin, we test six hypotheses about factors determining the developmental character of particular institutions. Implications of results for theory and for methodological practices of future studies in this field are discussed. PMID:26543407

  17. Comparative study of different venous reflux duplex quantitation parameters.

    PubMed

    Valentín, L I; Valentín, W H

    1999-09-01

    The objective of this study was to compare different quantitation parameters of venous reflux by duplex scan in different venous disease manifestations. Duplex scan is a new modality to quantify venous reflux. Several studies propose different parameters. In addition, there is controversy about the importance of deep and superficial involvement in different disease manifestations. It is not clear whether there is an increased venous reflux associated with varied clinical stages. Venous conditions were classified in seven stages and their differences for several quantitation variables studied. Most quantitation variables, such as average and peak velocity, average and peak flow, and reflux volume disclosed significantly increased reflux from normal, pain only, and edema group to varicose vein, with or without edema, to lipodermatosclerosis and ulcer groups at every location in the lower extremity. Reflux time was not as consistent as other variables. Totalization of the results of every parameter for the whole extremity points to an increased reflux from pain only to edema and from lipodermatosclerosis to ulcer group. Chronic edema is not usually associated with increased venous reflux. The greater saphenous vein (superficial system) seems to be the main contributor to reflux in all stages of disease. Different quantitation methods of venous reflux are equivalent. Increased deep and superficial reflux and its totalization are associated with a more advanced disease stage. Reflux time may be the least useful variable. Chronic edema is frequently not associated with venous reflux. Greater saphenectomy may be the most useful intervention, even in the presence of deep vein reflux. PMID:10496498

  18. Comparing the Leadership Styles of Two Heads of Department at Carnelian School: Comparative Case Studies

    ERIC Educational Resources Information Center

    Parascandalo, Marthese

    2014-01-01

    The purpose of this dissertation was to compare and contrast the Leadership Styles of two Heads of Department who work at Carnelian Secondary School (anonymized). It augments a previous paper (Parascandalo 2011) which examined the role of the middle leader in secondary schools in educational literature. The investigation by means of two…

  19. Pain assessment of the intratympanic injections: a prospective comparative study.

    PubMed

    Belhassen, Sarah; Saliba, Issam

    2012-12-01

    The objective of the study is to compare the pain level of three methods of intratympanic (IT) injections using prospective, randomized clinical study in a tertiary care center. 39 patients with Ménière's disease and 30 patients with sudden sensorineural hearing loss are included. Excluded were patients treated for a chronic pain or those who took any pain killer for the last 24 h. Each patient received one IT injection a week, for three consecutive weeks. Three methods of IT injections were compared, with the application of EMLA cream on the tympanic membrane filling the external auditory canal 60 min before the procedure, with subcutaneous injection of lidocaine 1% with 1:100,000 epinephrine in the external auditory canal, and finally with an IT injection without any previous anesthesia. The pain intensity was immediately measured at 5 min, and then 45 min after the procedure, each time using four pain rating scales (visual analogue scale, numerical rating scale, verbal rating scale and categorical rating scale). No difference in pain intensity between the three methods of IT injections was detected by the visual analogue scale and numerical rating scale (p > 0.05). 45.8% of patients preferred the IT injection without previous anesthesia. However, methylprednisolone has been associated with pain intensity greater than that of gentamicin 45 min after the injection (p < 0.05). The IT injection performed without any previous anesthesia is an interesting option since it has not been shown to be more painful than the other methods of injections, and spares the patient from disadvantages associated with the anesthesia. PMID:22203120

  20. Malaria and risk of predation: a comparative study of birds.

    PubMed

    Møller, Anders Pape; Nielsen, Jan Tøttrup

    2007-04-01

    Predators have been hypothesized to prey on individuals in a poor state of health, although this hypothesis has only rarely been examined. We used extensive data on prey abundance and availability from two long-term studies of the European Sparrowhawk (Accipiter nisus) and the Eurasian Goshawk (Accipiter gentilis) to quantify the relationship between predation risk of different prey species and infection with malaria and other protozoan blood parasites. Using a total of 31 745 prey individuals of 65 species of birds from 1709 nests during 1977-1997 for the Sparrowhawk and a total of 21 818 prey individuals of 76 species of birds from 1480 nests for the Goshawk during 1977-2004, we show that prey species with a high prevalence of blood parasites had higher risks of predation than species with a low prevalence. That was also the case when a number of confounding variables of prey species, such as body mass, breeding sociality, sexual dichromatism, and similarity among species in risk of predation due to common descent, were controlled in comparative analyses of standardized linear contrasts. Prevalence of the genera Haemoproteus, Leucocytozoon, Plasmodium, and Trypanosoma were correlated with each other, and we partitioned out the independent effects of different protozoan genera on predation risk in comparative analyses. Prevalence of Haemoproteus, Leucocytozoon, and Plasmodium accounted for interspecific variation in predation risk for the two raptors. These findings suggest that predation is an important factor affecting parasite-host dynamics because predators tend to prey on hosts that are more likely to be infected, thereby reducing the transmission success of parasites. Furthermore, this study demonstrates that protozoan infections are a common cause of death for hosts mediated by increased risk of predation. PMID:17536704

  1. Systemic Inflammation in Cardiovascular and Periodontal Disease: Comparative Study

    PubMed Central

    Glurich, Ingrid; Grossi, Sara; Albini, Boris; Ho, Alex; Shah, Rashesh; Zeid, Mohamed; Baumann, Heinz; Genco, Robert J.; De Nardin, Ernesto

    2002-01-01

    Epidemiological studies have implicated periodontal disease (PD) as a risk factor for the development of cardiovascular disease (CVD). These studies addressed the premise that local infection may perturb the levels of systemic inflammatory mediators, thereby promoting mechanisms of atherosclerosis. Levels of inflammatory mediators in the sera of subjects with only PD, only CVD, both diseases, or neither condition were compared. Subjects were assessed for levels of C-reactive protein (CRP), serum amyloid A (SAA), ceruloplasmin, α1-acid-glycoprotein (AAG), α1-antichymotrypsin (ACT), and the soluble cellular adhesion molecules sICAM-1 and sVCAM by enzyme-linked immunoabsorbent and/or radial immunodiffusion assays. CRP levels in subjects with either condition alone were elevated twofold above subjects with neither disease, whereas a threefold increase was noted in subjects with both diseases (P = 0.0389). Statistically significant increases in SAA and ACT were noted in subjects with both conditions compared to those with one or neither condition (P = 0.0162 and 0.0408, respectively). Ceruloplasmin levels were increased in subjects with only CVD (P = 0.0001). Increases in sVCAM levels were noted in all subjects with CVD (P = 0.0054). No differences in sICAM levels were noted among subject groups. A trend toward higher levels of AAG was noted in subjects with both conditions and for ACT in subjects with only PD. Immunohistochemical examination of endarterectomy specimens of carotid arteries from subjects with atherosclerosis documented SAA and CRP deposition in association with atheromatous lesions. The data support the hypothesis that localized persistent infection may influence systemic levels of inflammatory mediators. Changes in inflammatory mediator levels potentially impact inflammation-associated atherosclerotic processes. PMID:11874889

  2. Comparative studies of brain activation with MEG and functional MRI

    SciTech Connect

    George, J.S.; Aine, C.J.; Sanders, J.A.; Lewine, J.D.; Caprihan, A.

    1993-12-31

    The past two years have witnessed the emergence of MRI as a functional imaging methodology. Initial demonstrations involved the injection of a paramagnetic contrast agent and required ultrafast echo planar imaging capability to adequately resolve the passage of the injected bolus. By measuring the local reduction in image intensity due to magnetic susceptibility, it was possible to calculate blood volume, which changes as a function of neural activation. Later developments have exploited endogenous contrast mechanisms to monitor changes in blood volume or in venous blood oxygen content. Recently, we and others have demonstrated that it is possible to make such measurements in a clinical imager, suggesting that the large installed base of such machines might be utilized for functional imaging. Although it is likely that functional MRI (fMRI) will subsume some of the clinical and basic neuroscience applications now touted for MEG, it is also clear that these techniques offer different largely complementary, capabilities. At the very least, it is useful to compare and cross-validate the activation maps produced by these techniques. Such studies will be valuable as a check on results of neuromagnetic distributed current reconstructions and will allow better characterization of the relationship between neurophysiological activation and associated hemodynamic changes. A more exciting prospect is the development of analyses that combine information from the two modalities to produce a better description of underlying neural activity than is possible with either technique in isolation. In this paper we describe some results from initial comparative studies and outline several techniques that can be used to treat MEG and fMRI data within a unified computational framework.

  3. Gasification of New Zealand coals: a comparative simulation study

    SciTech Connect

    Smitha V. Nathen; Robert D. Kirkpatrick; Brent R. Young

    2008-07-15

    The aim of this study was to conduct a preliminary feasibility assessment of gasification of New Zealand (NZ) lignite and sub-bituminous coals, using a commercial simulation tool. Gasification of these coals was simulated in an integrated gasification combined cycle (IGCC) application and associated preliminary economics compared. A simple method of coal characterization was developed for simulation purposes. The carbon, hydrogen, and oxygen content of the coal was represented by a three component vapor solid system of carbon, methane, and water, the composition of which was derived from proximate analysis data on fixed carbon and volatile matter, and the gross calorific value, both on a dry, ash free basis. The gasification process was modeled using Gibb's free energy minimization. Data from the U.S. Department of Energy's Shell Gasifier base cases using Illinios No. 6 coal was used to verify both the gasifier and the IGCC flowsheet models. The H:C and O:C ratios of the NZ coals were adjusted until the simulated gasifier output composition and temperature matched the values with the base case. The IGCC power output and other key operating variables such as gas turbine inlet and exhaust temperatures were kept constant for study of comparative economics. The results indicated that 16% more lignite than sub-bituminous coal was required. This translated into the requirement of a larger gasifier and air separation unit, but smaller gas and steam turbines were required. The gasifier was the largest sole contributor (30%) to the estimated capital cost of the IGCC plant. The overall cost differential associated with the processing of lignite versus processing sub-bituminous coal was estimated to be of the order of NZ $0.8/tonne. 13 refs., 9 tabs.

  4. International Comparative Studies in Education: Descriptions of Selected Large-Scale Assessments and Case Studies.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC. Commission on Behavioral and Social Sciences and Education.

    Since its inception in 1988, the Board on International Comparative Studies in Education (BICSE) has monitored U.S. participation in those cross national comparative studies in education that are funded by its sponsors, the National Science Foundation and the National Center for Education Statistics. This set of international study descriptions…

  5. Histomorphometric evaluation of strontium-containing nanostructured hydroxyapatite as bone substitute in sheep.

    PubMed

    Machado, Callinca Paolla Gomes; Sartoretto, Suelen Cristina; Alves, Adriana Terezinha Neves Novellino; Lima, Inayá Barbosa Correa; Rossi, Alexandre Malta; Granjeiro, José Mauro; Calasans-Maia, Mônica Diuana

    2016-01-01

    The aim of this study is to evaluate the biocompatibility and osteoconductivity in surgical defects of sheep tibias filled with 1% strontium-containing nanostructured hydroxyapatite microspheres (SrHA), stoichiometric hydroxyapatite without strontium microspheres (HA), or blood clots. Santa Ines sheep were subjected to three perforations on the medial side of the left tibia. The biomaterials were characterized by X-ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) before implantation and by X-Ray Microfluorescence (µFRX) and Scanning Electron Microscopy (SEM) after sheep tibias implantation. Surgical defects were filled with blood clots (control), SrHA (Group 1) or HA (Group 2). After 30 days, 5-µm bone blocks were obtained for histological evaluation, and the blocks obtained from 1 animal were embedded in methylmethacrylate for undecalcified sections. Mononuclear inflammatory infiltrate remained mild in all experimental groups. Giant cells were observed surrounding biomaterials particles of both groups and areas of bone formation were detected in close contact with biomaterials. All groups showed newly formed bone from the periphery to the center of the defects, which the control, HA and SrHA presented 36.4% (± 21.8), 31.2% (± 14.7) and 26.2% (± 12.9) of newly formed bone density, respectively, not presenting statistical differences. In addition, the connective tissue density did not show any significant between groups. The SrHA showing a higher volume density of biomaterial (51.2 ± 14.1) present in the defect compared to HA (32.6 ± 8.5) after 30 days (p = 0.03). Microspheres containing 1% SrHA or HA can be considered biocompatible, have osteoconductive properties and may be useful biomaterials for clinical applications. PMID:27191738

  6. Comparative studies on nitrogen budgets of closed shrimp polyculture systems

    NASA Astrophysics Data System (ADS)

    Qi, Zhen-Xiong; Li, De-Shang; Zhang, Man-Ping; Dong, Shuang-Lin

    2001-09-01

    April to October, 1997 comparative studies on the nitrogen budgets of closed shrimp polyculture systems showed that, in all the studied polyculture systems, nitrogen from feeds and fertilizers were the main input items, which comprised 70.7% 83.9% of the total input nitrogen 3.2% 7.4% of which was provided by nitrogen fixation. It was in monoculture enclosures (Y-4, Y-11 and Y-12) that the percentage reached the maximum value. The output nitrogen in harvested products comprised 10.8% 24.6% of total input nitrogen, and the highest percentage, 24.6%, was found in shrimp-fish-tagelus polyculture systems. In shrimp monoculture and shrimp-fish polyculture systems, they were 19.1% and 21.9% respectively. The nitrogen utilization efficiency was different and varied from 12.2% was found in shrimp-tagelus polyculture systems. The lowest, 12.2%, was found in shrimp monoculture systems. All the nitrogen utilization efficiencies in shrimp-fish systems or shrimp-scallop systems seemed to be higher than that of the monoculture system, but they showed little statistical difference. The main outputs of nitrogen were found in sediment mud, and comprised 48.2% 60.8% of the total, input, the lowest percentage was found in shrimp-fish-tagelus polyculture systems, and the highest percentage in shrimp-scallop systems. During the experiment, nitrogen lost through denitrification and ammonia volatilization comprised 1.9% 6. 2%, averaged 2.8%, of the total input, and the loss through seepage comprised 5.9% 8.9% of the total. The estimated nitrogen attached to the enclosure wall comprised 3.7% 13.3% of the total, and was highest in shrimp monoculture systems. Compared with the classic shrimp farming industry, the closed shrimp polyculture systems may improve the nitrogen utilization efficiency, and hence reduce the environmental impacts on coastal waters. The nitrogen discharging rates for all the studied polyculture systems ranged from 3.0% to 6. 0% of total input nitrogen.

  7. Breast imaging with ultrasound tomography: a comparative study with MRI

    NASA Astrophysics Data System (ADS)

    Ranger, Bryan; Littrup, Peter; Duric, Neb; Li, Cuiping; Schmidt, Steven; Lupinacci, Jessica; Myc, Lukasz; Szczepanski, Amy; Rama, Olsi; Bey-Knight, Lisa

    2010-03-01

    The purpose of this study was to investigate the performance of an ultrasound tomography (UST) prototype relative to magnetic resonance (MR) for imaging overall breast anatomy and accentuating tumors relative to background tissue. The study was HIPAA compliant, approved by the Institutional Review Board, and performed after obtaining the requisite informed consent. Twenty-three patients were imaged with MR and the UST prototype. T1 weighted images with fat saturation, with and without gadolinium enhancement, were used to examine anatomical structures and tumors, while T2 weighted images were used to identify cysts. The UST scans generated sound speed, attenuation, and reflection images. A qualitative visual comparison of the MRI and UST images was then used to identify anatomical similarities. A more focused approach that involved a comparison of reported masses, lesion volumes, and breast density was used to quantify the findings from the visual assessment. Our acoustic tomography prototype imaged distributions of fibrous stroma, parenchyma, fatty tissues, and lesions in patterns similar to those seen in the MR images. The range of thresholds required to establish tumor volume equivalency between MRI and UST suggested that a universal threshold for isolating masses relative to background tissue is feasible with UST. UST has demonstrated the ability to visualize and characterize breast tissues in a manner comparable to MRI. Thresholding techniques accentuate masses relative to background anatomy, which may prove clinically useful for early cancer detection.

  8. Spatial Navigation Strategies in Peromyscus: a Comparative Study.

    PubMed

    Jašarević, Eldin; Williams, Scott A; Roberts, R Michael; Geary, David C; Rosenfeld, Cheryl S

    2012-11-01

    A male advantage in spatial abilities is predicted to evolve in species where males rely on expansion of home territory to locate dispersed mates during the breeding season. We sought to examine mechanistic underpinnings of this evolved trait by comparing spatial navigational abilities in two species of Peromyscus that employ widely different reproductive strategies. Males and females from outbred stocks of deer mice (P. maniculatus bairdii) in which males engage in territorial expansion and mate search and California mice (P. californicus insignis), in which males do not, were administered tasks that assessed spatial learning and memory, and activity and exploratory behaviours. The maze employed for these studies included four spatial cues that could be used to aid in locating 1 of 12 potential escape holes. As predicted, male deer mice outperformed conspecific females and California mice males in maze performance and memory, and this difference appeared to be due to extent to which animals used spatial cues to guide maze navigation. Consistent with territorial expansion as a component of competition for mates, male deer mice were more active and engaged in more exploratory and less anxiety-related behaviours than conspecific females and California mice males. The results have implications for understanding and studying the cognitive and behavioural mechanisms that have evolved through male-male competition that involves territorial expansion and mate search. PMID:23355748

  9. Pupil dilation using drops vs gel: a comparative study

    PubMed Central

    Moisseiev, E; Loberman, D; Zunz, E; Kesler, A; Loewenstein, A; Mandelblum, J

    2015-01-01

    Purpose To compare the efficacy in pupil dilation and degree of discomfort between topical instillation of mydriatic drops and gel. Methods The study included 60 patients with no previous ocular history of trauma and surgery. One eye was dilated with two drops (tropicamide 0.5% and phenylephrine 10%), and the other with one drop of gel (tropicamide 0.5%+phenylephrine 5%). Pupil size was measured by a Colvard pupillometer at baseline and 5, 15, 30, and 45 min following instillation. Pain upon instillation was measured by visual analog scale (VAS). Results There was no difference in pupil size at baseline. Use of the gel achieved greater mydriasis than drops (P=0.01), and was also associated with lower pain scores (P=0.003). In diabetic patients, pupil size was smaller at baseline and following instillation of drops and gel. Use of the gel achieved an even greater degree of pupil dilation in this subset of patients than drops (P=0.019). Conclusions Gel formulation achieved significantly greater pupil dilation than drops, despite a lower concentration of phenylephrine, and was also associated with significantly lower patient discomfort. This study is the first report of improved mydriatic efficacy in diabetic patients. PMID:25857606

  10. Spatial Navigation Strategies in Peromyscus: a Comparative Study

    PubMed Central

    Jašarević, Eldin; Williams, Scott A.; Roberts, R. Michael; Geary, David C.; Rosenfeld, Cheryl S.

    2012-01-01

    A male advantage in spatial abilities is predicted to evolve in species where males rely on expansion of home territory to locate dispersed mates during the breeding season. We sought to examine mechanistic underpinnings of this evolved trait by comparing spatial navigational abilities in two species of Peromyscus that employ widely different reproductive strategies. Males and females from outbred stocks of deer mice (P. maniculatus bairdii) in which males engage in territorial expansion and mate search and California mice (P. californicus insignis), in which males do not, were administered tasks that assessed spatial learning and memory, and activity and exploratory behaviours. The maze employed for these studies included four spatial cues that could be used to aid in locating 1 of 12 potential escape holes. As predicted, male deer mice outperformed conspecific females and California mice males in maze performance and memory, and this difference appeared to be due to extent to which animals used spatial cues to guide maze navigation. Consistent with territorial expansion as a component of competition for mates, male deer mice were more active and engaged in more exploratory and less anxiety-related behaviours than conspecific females and California mice males. The results have implications for understanding and studying the cognitive and behavioural mechanisms that have evolved through male-male competition that involves territorial expansion and mate search. PMID:23355748

  11. Comparative studies on the status of Indonesian coral reefs

    NASA Astrophysics Data System (ADS)

    Soekarno, R.

    Coral reefs are of great economic importance for Indonesia. Unfortunately these resources are suffering from increasing human pressure. Several factors may cause the degradation of coral reefs, including the consequences of several human activities. Activities indirectly affecting the quality of the reefs are land-based activities such as deforestation, agriculture intensification, industrialization and domestic waste disposal. Direct use of the reefs, e.g. by coral mining, fish blasting and other fishing and collecting activities, is of greater and more widespread importance. Therefore, a rational management of the reef resources is urgently needed. Management is impossible without simple means of monitoring the status of reefs. One factor, living coral cover, has been determined for several years in many areas, including those studied during the Snellius-II Expedition. This allowed a comparative study of several different areas, which showed that coral cover is often very useful as an indication of the quality of reefs. It was found that the diversity of reef fishes is correlated with the condition of reefs as determined by the percentage cover of living coral.

  12. Comparative study of biogenic and abiotic iron-containing materials

    NASA Astrophysics Data System (ADS)

    Cherkezova-Zheleva, Z.; Shopska, M.; Paneva, D.; Kovacheva, D.; Kadinov, G.; Mitov, I.

    2016-12-01

    Series of iron-based biogenic materials prepared by cultivation of Leptothrix group of bacteria in different feeding media ( Sphaerotilus-Leptothrix group of bacteria isolation medium, Adler, Lieske and silicon-iron-glucose-peptone) were studied. Control samples were obtained in the same conditions and procedures but the nutrition media were not infected with bacteria, i.e. they were sterile. Room and low temperature Mössbauer spectroscopy, powder X-ray diffraction (XRD), and infrared spectroscopy (IRS) were used to reveal the composition and physicochemical properties of biomass and respective control samples. Comparative analysis showed differences in their composition and dispersity of present phases. Sample composition included different ratio of nanodimensional iron oxyhydroxide and oxide phases. Relaxation phenomena such as superparamagnetism or collective magnetic excitation behaviour were registered for some of them. The experimental data showed that the biogenic materials were enriched in oxyhydroxides of high dispersion. Catalytic behaviour of a selected biomass and abiotic material were studied in the reaction of CO oxidation. In situ diffuse-reflectance (DR) IRS was used to monitor the phase transformations in the biomass and CO conversion.

  13. A comparative study of trained and untrained rabindrasangeet singers.

    PubMed

    Chatterjee, Indranil; Kumar, Suman; Chattopadhyay, Durba

    2012-12-01

    This scientific paper proposes an analytic framework specifically for Rabindrasangeet singing that models the time-varying physical and expressive characteristics unique to an individual voice through a phonetogram analysis. The present study incorporates the most popular Rabindrasangeet into account for analysis to get an idea about the specific numerical data regarding the fundamental frequency, semitones, SPL range, and area as well as to give a precise guideline to those clients. While comparing the trained and untrained singers both males and females the F0 parameter is found to be louder in trained group. The mean semitone is always higher in females than in males and the trained male subjects have significantly higher SPL range than trained female subjects and trained females have higher SPL range than untrained female subjects. The enclosed area is larger in trained singers and more in females than males. Results of this study indicate differences between untrained and trained phonetograms. These differences can be attributed to greater natural capacities in trainedsubjects or a superior learned control over the voice mechanism. PMID:24294579

  14. Comparative Study of Clinically Used NiTi Orthodontic Wires

    NASA Astrophysics Data System (ADS)

    Wang, Qiang; Zhang, Yang; Hao, Fengyu; Yang, Ke; Tan, Lili

    The purpose of the study was to comparatively investigate two NiTi orthodontic wires. It is valuable to determine the phase transformation temperature and corrosion characteristics of the orthodontic wires to further study the shape memory effect and corrosion resistance properties. Optical microscope and EDX analysis were used for microstructure characteristics and composition analysis. Differential scanning calorimetry (DSC) was carried out to identify the phase transformation behavior of the two wires. Electrochemical tests in artificial saliva at 37 ±1°C including polarization and electrochemical impedance spectroscopy (EIS) were used to assess the corrosion resistance and corrosion mechanism of the wires. It was found that the transformation temperature range of A-wire (imported) is narrower while the As and Af are close to the body temperature, which is more suitable in the orthodontic operation at early stage. The corrosion current density of A-wire is lower than that of B-wire (domestically made) while the corrosion potential is higher. EIS test results indicated that the corrosion mechanism was the same. However, the oxide layer formed on the surface of A-wire is more protective.

  15. Comparative study of analysis methods in biospeckle phenomenon

    NASA Astrophysics Data System (ADS)

    da Silva, Emerson Rodrigo; Muramatsu, Mikiya

    2008-04-01

    In this work we present a review of main statistical properties of speckle patterns and accomplish a comparative study of the more used methods for analysis and extraction of information from optical grainy. The first and second order space-time statistics are dicussed in an overview perspective. The biospeckle phenomenon has detailed attention, specially in its application on monitoring of activity in tissues. The main techniques used to obtain information from speckle patterns are presented, with special prominence to autocorrelation function, co-occurrence matrices, Fujii's method, Briers' contrast and spatial and temporal contrast analisys (LASCA and LASTCA). An incipient method for analysis, based on the study of sucessive correlations contrast, is introduced. Numerical simulations, using diferent probability density functions for velocities of scatterers, were made with two objectives: to test the analysis methods and to give subsidies for interpretation of in vivo results. Vegetable and animal tissues are investigated, achieving the monitoring of senescence process and vascularization maps on leaves, the accompaniment of fungi contamined fruits, the mapping of activity in flowers and the analisys of healing in rats subjected to abdominal surgery. Experiments using the biospeckle phenomenon in microscopy are carried out. At last, it is evaluated the potentiality of biospeckle as diagnosis tool in chronic vein ulcer cared with low intensity laser therapy and the better analysis methods for each kind of tissue are pointed.

  16. Comparative study of different surface decontaminants on chicken quality.

    PubMed

    Sinhamahapatra, M; Biswas, S; Das, A K; Bhattacharyya, D

    2004-10-01

    (1) A comparative study on the effect of different surface decontaminants: hot water at 70 degrees C for one minute; 2% lactic acid for 30 s; 1200 p.p.m. acidified sodium chlorite (ASC) solution for 5 s and 50 p.p.m. chlorine solution for 5 min in the form of dips and sprays on the surface of dressed broilers for 0, 24 and 48 h of storage was conducted. (2) The variables studied were, total plate count (TPC), presumptive coliform count (PCC), pH and extract release volume (ERV). All treatments reduced TPC and PCC. (3) Lactic acid dip and hot water dip were the most effective for reducing TPC (1.36 and 1.28 log/cm2, respectively) with no significant difference between them. (4) ASC and hot water in dip could diminish PCC (1.37 and 1.34 log/cm2, respectively) and did not vary significantly. (5) No treatment affected muscle pH, water holding capacity (WHC), ERV, appearance, smell, tenderness and overall acceptability of treated broilers significantly. (6) Hot water treatment is the cheapest, most convenient and simplest decontamination technique for hygienic and wholesome poultry production. PMID:15623215

  17. A comparative sealability study of different retrofilling materials.

    PubMed

    Ozata, F; Erdilek, N; Tezel, H

    1993-07-01

    The purpose of this study was to compare the sealing ability of high-copper amalgam, glass ionomer cement, and silver glass ionomer cement as retrofilling materials when used with and without varnish. Seventy extracted human single-rooted anterior teeth were instrumented and the root canals obturated with laterally condensed gutta-percha and sealer. The apical 3 mm of each root was resected and a 2 mm-deep apical Class I preparation cut. The roots were then randomly allocated to six groups of 10 teeth and retrofilled with one of the experiment materials. Group I comprised high-copper amalgam; group 2, high-copper amalgam with cavity varnish; group 3, glass ionomer cement without varnish; group 4, glass ionomer cement with varnish; group 5, silver glass ionomer cement without varnish; and group 6, silver glass ionomer cement with varnish. Two groups of five roots each were used as positive and negative controls. The root surfaces were coated with nail polish and specimens immersed in 2% methylene blue solution for 14 days. After vertical sectioning, dye penetration was examined under a stereomicroscope. The results of the study were analysed statistically. The sealing ability of the conventional glass ionomer cement with varnish was significantly better while dye penetration was higher in silver glass ionomer cement without varnish group than the other groups (P < 0.01). PMID:8225643

  18. Traditional and accelerated Ponseti technique: a comparative study.

    PubMed

    Elgohary, Hatem S A; Abulsaad, Mazen

    2015-07-01

    The purpose of this study was to compare the results of traditional and accelerated Ponseti techniques to clarify whether this technique can be done safely in reduced time with complete correction of the deformity and without complications. A total of 66 feet in 41 children with idiopathic club foot and with Pirani score no <4 were included; of these, 34 feet in 20 children were managed with the traditional Ponseti method with one cast a week, in the other 32 feet in 21 children, an accelerated technique was used with casting twice a week, and the Pirani score was used for initial assessment and for follow-up. The results were comparable for both groups; the mean number of casts for full correction was 4.88 ± 0.88 in the traditional group and 5.16 ± 0.72 in the accelerated group. Initial correction was obtained in all cases in both groups, and relapses were observed in 14.7 % in the traditional group and in 15.6 % in the accelerated group. Deformities required from four to seven casts for correction in both groups. There was a statistically significant reduction in the mean time required for correction from onset of manipulation till tenotomy or correction of equines without tenotomy which was 33.36 ± 6.69 days (21-42 days) in the traditional Ponseti group and 18.13 ± 3.02 days (11-22 days) in accelerated Ponseti (P = 0.001). Accelerated Ponseti technique significantly reduces the correction time without affecting the final results; it is quite as safe and effective as the traditional Ponseti. PMID:25633123

  19. Mycobacterial species as case-study of comparative genome analysis.

    PubMed

    Zakham, F; Belayachi, L; Ussery, D; Akrim, M; Benjouad, A; El Aouad, R; Ennaji, M M

    2011-01-01

    The genus Mycobacterium represents more than 120 species including important pathogens of human and cause major public health problems and illnesses. Further, with more than 100 genome sequences from this genus, comparative genome analysis can provide new insights for better understanding the evolutionary events of these species and improving drugs, vaccines, and diagnostics tools for controlling Mycobacterial diseases. In this present study we aim to outline a comparative genome analysis of fourteen Mycobacterial genomes: M. avium subsp. paratuberculosis K—10, M. bovis AF2122/97, M. bovis BCG str. Pasteur 1173P2, M. leprae Br4923, M. marinum M, M. sp. KMS, M. sp. MCS, M. tuberculosis CDC1551, M. tuberculosis F11, M. tuberculosis H37Ra, M. tuberculosis H37Rv, M. tuberculosis KZN 1435 , M. ulcerans Agy99,and M. vanbaalenii PYR—1, For this purpose a comparison has been done based on their length of genomes, GC content, number of genes in different data bases (Genbank, Refseq, and Prodigal). The BLAST matrix of these genomes has been figured to give a lot of information about the similarity between species in a simple scheme. As a result of multiple genome analysis, the pan and core genome have been defined for twelve Mycobacterial species. We have also introduced the genome atlas of the reference strain M. tuberculosis H37Rv which can give a good overview of this genome. And for examining the phylogenetic relationships among these bacteria, a phylogenic tree has been constructed from 16S rRNA gene for tuberculosis and non tuberculosis Mycobacteria to understand the evolutionary events of these species. PMID:21396338

  20. Comparative study of forensic psychiatric system between China and America.

    PubMed

    Li, Gangqin; Gutheil, Thomas G; Hu, Zeqing

    2016-01-01

    Laws and regulations about the forensic psychiatric systems in China and America were compared, and suggestions for improving the forensic psychiatric system of China were provided. There are many differences regarding the role of the forensic psychiatrist, the initiation of the assessment and the admission of expert opinion because of elements in the legal systems in China and America. The Chinese system has the advantages of objectivity, cost saving and high efficiency; but it has deficiencies in procedural justice and the admission of expert opinion. China can persist with the current system while taking measures to give more rights to the litigants to participate in their assessment, and while improving the quality and utility of the expert opinion; however, this review article will compare broadly the two systems without addressing human rights issues or procedural justice issues, nor will it presume to address the entirety of Chinese systems. In addition, China is developing its legal system for dealing with the mentally ill defendant in situations involving the criminal justice system and civil commitment. Although China enacted new laws regarding the mandatory treatment for the mentally ill, both in criminal and civil systems, there remain many aspects to be improved, including but not limited to a system of review of the decision to detain a patient on psychiatric grounds, and the need for provisions in the laws preventing indefinite detention. From this viewpoint, America's laws and regulations are instructive for us, in matters such as the method of dealing with the mentally ill defendant who is "incompetent to stand trial", "not guilty only by reason of insanity" or "guilty but mentally ill". The conditional release of the committed mentally ill person and the special programs in the forensic security hospital are all worthy of study by China in order to manage the mentally ill offender and to reduce the recidivism rate. PMID:27292971

  1. Comparative Modeling Studies of Boreal Water and Carbon Balance

    NASA Technical Reports Server (NTRS)

    Coughlan, J.; Peterson, David L. (Technical Monitor)

    1997-01-01

    The coordination of the modeling and field efforts for an Intensive Field Campaign (IFC) may resemble the chicken and egg dilemma. This session's theme advocates that early and proactive involvement by modeling teams can produce a scientific and operational benefit for the IFC and Experiment. This talk will provide some examples and suggestions originating from the NASA funded IFC's of the FIFE First ISLSCP (International Satellite Land Surface Climatology Project) Field Experiment, Oregon Transect Ecosystem Research (OTTER) and predominately Boreal Ecosystem-Atmosphere Study (BOREAS) Experiments. In February 1994 and prior to the final selection of the BOREAS study sites, a group of funded BOREAS investigators agreed to run their models with data for five community types representing the proposed tower flux sites. All participating models were given identical initial values and boundary conditions and driven with identical climate data. The objectives of the intercomparison exercise were: 1) compare simulation results of participating terrestrial, hydrological, and atmospheric models over selected time frames; 2) learn about model behavior and sensitivity to estimated boreal site and vegetation definitions; 3) prioritize BOREAS field data collection efforts supporting modeling studies; 4) identify individual model deficiencies as early as possible. Out of these objectives evolved some important coordination and science issues for the BOREAS Experiment that can be generalized to IFCs and long term archiving of the data. Some problems are acceptable because they are endemic to maintaining fair and open competition prior to the peer review process. Others are logistical and addressable through application of planning, management, and information sciences. This investigator has identified one source of measurement and model incompatibility that is manifest in the IFC scaling approach. Although intuitively obvious, scaling problems are already more formally defined in

  2. Comparative study of the synthesis of layered transition metal molybdates

    SciTech Connect

    Mitchell, S.; Gomez-Aviles, A.; Gardner, C.; Jones, W.

    2010-01-15

    Mixed metal oxides (MMOs) prepared by the mild thermal decomposition of layered double hydroxides (LDHs) differ in their reactivity on exposure to aqueous molybdate containing solutions. In this study, we investigate the reactivity of some T-Al containing MMOs (T=Co, Ni, Cu or Zn) towards the formation of layered transition metal molybdates (LTMs) possessing the general formula AT{sub 2}(OH)(MoO{sub 4}){sub 2}.H{sub 2}O, where A=NH{sub 4}{sup +}, Na{sup +} or K{sup +}. The phase selectivity of the reaction was studied with respect to the source of molybdate, the ratio of T to Mo and the reaction pH. LTMs were obtained on reaction of Cu-Al and Zn-Al containing MMOs with aqueous solutions of ammonium heptamolybdate. Rehydration of these oxides in the presence of sodium or potassium molybdate yielded a rehydrated LDH phase as the only crystalline product. The LTM products obtained by the rehydration of MMO precursors were compared with LTMs prepared by direct precipitation from the metal salts in order to study the influence of preparative route on their chemical and physical properties. Differences were noted in the composition, morphology and thermal properties of the resulting products. - Graphical abstract: Mixed metal oxides (MMOs) derived from layered double hydroxide precursors differ in their reactivity on exposure to aqueous molybdate containing solutions. We investigate the influence of the molybdate source, the rehydration pH and the ratio of T/Mo on the reactivity of some T-Al containing MMOs (T=Co, Ni, Cu or Zn) towards the formation of layered transition metal molybdates of general formula AT{sub 2}(OH)(MoO{sub 4}){sub 2}.H{sub 2}O (where A{sup +}=NH{sub 4}{sup +}, K{sup +} or Na{sup +}).

  3. Mesiodistal odontometrics as a distinguishing trait: A comparative preliminary study

    PubMed Central

    Sravya, Taneeru; Dumpala, Rakesh Kumar; Guttikonda, Venkateswara Rao; Manchikatla, Praveen Kumar; Narasimha, Vanajakshi China

    2016-01-01

    Introduction: Sex determination is a vital step in reconstructing an individual profile from unidentified skeletal remnants. Variations in tooth size are influenced by genetic and environmental factors. Tooth size variations have been reported among different populations. Aim: To identify the sex by determining the mesiodistal (MD) dimensions of maxillary canines. Objectives: (1) To compare the MD diameter of all maxillary canines — (a) in the entire urban and tribal population, (b) in urban male and urban female populations, (c) in tribal male and tribal female populations, and (d) in the entire male and female populations and (2) To estimate the percentage of sexual dimorphism individually in urban and tribal populations. Materials and Methods: Fifty subjects each from urban and tribal populations in equal gender ratio were selected in Khammam district, Telangana, for the purpose of this study. After obtaining informed consent, maxillary study models of the selected subjects were made. MD diameters of left and right maxillary canines were measured on casts using vernier calipers. The obtained data were subjected to statistical analysis. Results: (1) The total tribal population showed a greater MD diameter of maxillary canines than the total urban population, (2) Urban males showed a greater MD diameter of maxillary canines than urban females, (3) Tribal males showed a greater MD diameter of maxillary canines than tribal females, (4) The entire male population showed a greater MD diameter of maxillary canines than the entire female population, and (5) The percentage of dimorphism between males and females in individual groups was found to be significant. Conclusion: The study showed maxillary canines exhibiting significant sexual dimorphism and can be used as a distinguishing trait for sex determination along with other procedures. PMID:27555727

  4. Comparative Climate Studies of Earth, Venus and Mars

    NASA Astrophysics Data System (ADS)

    Chassefiere, E.

    2008-12-01

    One of the most promising area in Solar System science is the comparative study of the three terrestrial planets (Venus, Earth, Mars). Why did the three planets evolve in such different ways, from relatively comparable initial states? The small size of Mars, favoring atmospheric escape, certainly played a role in making the present Mars so inhospitable. Venus has almost the same size and density as the Earth, and was probably initially endowed with similar amounts of volatile material. The absence of water in significant amounts on Venus, generally explained by intense primitive atmospheric escape, remains poorly constrained and understood. Two specific problems, related to Mars and Venus climate evolution, will be discussed in this talk. One major challenge of Mars studies is to determine the nature of the present Martian atmosphere: is it the residual of an old atmosphere, progressively lost by escape, or is it young, at steady state equilibrium between outgassing and escape? The possible detection of methane in Martian atmosphere suggests that methane currently is being produced, possibly signing outgassing, since methane is the thermodynamically favoured form of carbon, as released by potential volcanism or hydrothermalism, at low Martian temperature and pressure. Although no typical volcanic gas, like SO2, has ever been detected on Mars, the existence of recent lava flows (a few million years old) shows that a residual volcanism is still episodically active. Another possible tracer of outgassing, that is radon 222, seems promising, and could have been detected (although indirectly) in the Martian atmosphere from recent APXS (MER rovers) and Gamma Ray Spectrometer (Mars- Odyssey) measurements. The lack of any isotopic fractionation of carbon and oxygen in Martian CO2, as shown by existing measurements, suggests that the atmosphere of Mars is young, since it should have been fractionated by escape if it is old. This possibility of a young Martian atmosphere

  5. Scaling and Predictability in Stock Markets: A Comparative Study

    PubMed Central

    Zhang, Huishu; Wei, Jianrong; Huang, Jiping

    2014-01-01

    Most people who invest in stock markets want to be rich, thus, many technical methods have been created to beat the market. If one knows the predictability of the price series in different markets, it would be easier for him/her to make the technical analysis, at least to some extent. Here we use one of the most basic sold-and-bought trading strategies to establish the profit landscape, and then calculate the parameters to characterize the strength of predictability. According to the analysis of scaling of the profit landscape, we find that the Chinese individual stocks are harder to predict than US ones, and the individual stocks are harder to predict than indexes in both Chinese stock market and US stock market. Since the Chinese (US) stock market is a representative of emerging (developed) markets, our comparative study on the markets of these two countries is of potential value not only for conducting technical analysis, but also for understanding physical mechanisms of different kinds of markets in terms of scaling. PMID:24632944

  6. Liposomes- and ethosomes-associated distamycins: a comparative study.

    PubMed

    Cortesi, Rita; Romagnoli, Romeo; Drechsler, Markus; Menegatti, Enea; Zaid, Abdel N; Ravani, Laura; Esposito, Elisabetta

    2010-12-01

    The present article describes a comparative study of the performances of liposomes and ethosomes as specialized delivery systems for distamycin A (DA) and two of its derivatives. Liposomes and ethosomes were prepared by classical methods, extruded through polycarbonate filters, and characterized in terms of dimensions, morphology, and encapsulation efficiency. It was found that DA was associated with vesicles (either liposomes or ethosomes) by around 16.0%, while both derivatives of DA showed a percentage of association around 80% in the case of liposomes and around 50% in the case of ethosomes. In vitro antiproliferative activity experiments performed on cultured human and mouse leukemic cells demonstrated that vesicles were able to increase the activity of both derivatives of DA. In addition, it was demonstrated that the aging of both liposomes- and ethosomes-associated distamycin suspensions did not heavily influence the vesicle size, while all samples showed a relevant drug leakage with time. Moreover, according to the different physicochemical characteristics of DA and its derivatives (i.e., log P), vesicle-associated DA showed the highest loss of drug with respect to both its derivatives. In conclusion, the enhancement of drug activity expressed by these specialized delivery systems-associated DD could be interesting to obtain an efficient therapeutic effect aimed at reducing or minimizing toxic effects occurring with distamycins administration. PMID:19961302

  7. Scaling and predictability in stock markets: a comparative study.

    PubMed

    Zhang, Huishu; Wei, Jianrong; Huang, Jiping

    2014-01-01

    Most people who invest in stock markets want to be rich, thus, many technical methods have been created to beat the market. If one knows the predictability of the price series in different markets, it would be easier for him/her to make the technical analysis, at least to some extent. Here we use one of the most basic sold-and-bought trading strategies to establish the profit landscape, and then calculate the parameters to characterize the strength of predictability. According to the analysis of scaling of the profit landscape, we find that the Chinese individual stocks are harder to predict than US ones, and the individual stocks are harder to predict than indexes in both Chinese stock market and US stock market. Since the Chinese (US) stock market is a representative of emerging (developed) markets, our comparative study on the markets of these two countries is of potential value not only for conducting technical analysis, but also for understanding physical mechanisms of different kinds of markets in terms of scaling. PMID:24632944

  8. A framework for the comparative study of language.

    PubMed

    Uriagereka, Juan; Reggia, James A; Wilkinson, Gerald S

    2013-01-01

    Comparative studies of language are difficult because few language precursors are recognized. In this paper we propose a framework for designing experiments that test for structural and semantic patterns indicative of simple or complex grammars as originally described by Chomsky. We argue that a key issue is whether animals can recognize full recursion, which is the hallmark of context-free grammar. We discuss limitations of recent experiments that have attempted to address this issue, and point out that experiments aimed at detecting patterns that follow a Fibonacci series have advantages over other artificial context-free grammars. We also argue that experiments using complex sequences of behaviors could, in principle, provide evidence for fully recursive thought. Some of these ideas could also be approached using artificial life simulations, which have the potential to reveal the types of evolutionary transitions that could occur over time. Because the framework we propose has specific memory and computational requirements, future experiments could target candidate genes with the goal of revealing the genetic underpinnings of complex cognition. PMID:23864291

  9. Soft Tissue Phantoms for Realistic Needle Insertion: A Comparative Study.

    PubMed

    Leibinger, Alexander; Forte, Antonio E; Tan, Zhengchu; Oldfield, Matthew J; Beyrau, Frank; Dini, Daniele; Rodriguez Y Baena, Ferdinando

    2016-08-01

    Phantoms are common substitutes for soft tissues in biomechanical research and are usually tuned to match tissue properties using standard testing protocols at small strains. However, the response due to complex tool-tissue interactions can differ depending on the phantom and no comprehensive comparative study has been published to date, which could aid researchers to select suitable materials. In this work, gelatin, a common phantom in literature, and a composite hydrogel developed at Imperial College, were matched for mechanical stiffness to porcine brain, and the interactions during needle insertions within them were analyzed. Specifically, we examined insertion forces for brain and the phantoms; we also measured displacements and strains within the phantoms via a laser-based image correlation technique in combination with fluorescent beads. It is shown that the insertion forces for gelatin and brain agree closely, but that the composite hydrogel better mimics the viscous nature of soft tissue. Both materials match different characteristics of brain, but neither of them is a perfect substitute. Thus, when selecting a phantom material, both the soft tissue properties and the complex tool-tissue interactions arising during tissue manipulation should be taken into consideration. These conclusions are presented in tabular form to aid future selection. PMID:26666228

  10. Spheroid model study comparing the biocompatibility of Biodentine and MTA.

    PubMed

    Pérard, Matthieu; Le Clerc, Justine; Watrin, Tanguy; Meary, Fleur; Pérez, Fabienne; Tricot-Doleux, Sylvie; Pellen-Mussi, Pascal

    2013-06-01

    The primary objective of this study was to assess the biological effects of a new dentine substitute based on Ca₃SiO₅ (Biodentine™) for use in pulp-capping treatment, on pseudo-odontoblastic (MDPC-23) and pulp (Od-21) cells. The secondary objective was to evaluate the effects of Biodentine and mineral trioxide aggregate (MTA) on gene expression in cultured spheroids. We used the acid phosphatase assay to compare the biocompatibility of Biodentine and MTA. Cell differentiation was investigated by RT-qPCR. We investigated the expression of genes involved in odontogenic differentiation (Runx2), matrix secretion (Col1a1, Spp1) and mineralisation (Alp). ANOVA and PLSD tests were used for data analysis. MDPC-23 cells cultured in the presence of MTA had higher levels of viability than those cultured in the presence of Biodentine and control cells on day 7 (P = 0.0065 and P = 0.0126, respectively). For Od-21 cells, proliferation rates on day 7 were significantly lower in the presence of Biodentine or MTA than for control (P < 0.0001). Col1a1 expression levels were slightly lower in cells cultured in the presence of MTA than in those cultured in the presence of Biodentine and in control cells. Biodentine and MTA may modify the proliferation of pulp cell lines. Their effects may fluctuate over time, depending on the cell line considered. The observed similarity between Biodentine and MTA validates the indication for direct pulp-capping claimed by the manufacturers. PMID:23515903

  11. Frontotemporal Dementia in Southeast Asia: A Comparative Study

    PubMed Central

    Tan, Yee-Leng; Ng, Amanda; Kandiah, Nagaendran

    2013-01-01

    Background The clinical profile of frontotemporal dementia (FTD) in Southeast Asia is not known. We characterized and compared the demographic and clinical characteristics of FTD patients in Southeast Asia with North Asian and Western patients. Methods The study included Southeast Asian FTD patients presenting to a tertiary neurology institute. Behavioral variant (bv-FTD) and language variant (lv-FTD) subtypes of FTD were diagnosed based on the Lund-Manchester criteria. The patients were characterized according to demographics, clinical, neuroimaging and longitudinal profiles. Results Twenty-five bv-FTD and 19 lv-FTD patients were identified, with a female predominance ratio of 2:1 and a mean age of 56 years. The mean MMSE score was 16.2, and 88.4% of patients had memory symptoms. Over 5.1 ± 2.4 years of follow-up, 60% of bv-FTD and 36.8% of lv-FTD patients developed a second FTD syndrome. bv-FTD was the predominant type of FTD among Southeast Asians. Conclusion FTD represents an important cause of young-onset dementia in Southeast Asia. Greater awareness of FTD is required to ensure early diagnosis and management. PMID:23569453

  12. A comparative study of prebiotic and present day translational models

    NASA Technical Reports Server (NTRS)

    Rein, R.; Raghunathan, G.; Mcdonald, J.; Shibata, M.; Srinivasan, S.

    1986-01-01

    It is generally recognized that the understanding of the molecular basis of primitive translation is a fundamental step in developing a theory of the origin of life. However, even in modern molecular biology, the mechanism for the decoding of messenger RNA triplet codons into an amino acid sequence of a protein on the ribosome is understood incompletely. Most of the proposed models for prebiotic translation lack, not only experimental support, but also a careful theoretical scrutiny of their compatibility with well understood stereochemical and energetic principles of nucleic acid structure, molecular recognition principles, and the chemistry of peptide bond formation. Present studies are concerned with comparative structural modelling and mechanistic simulation of the decoding apparatus ranging from those proposed for prebiotic conditions to the ones involved in modern biology. Any primitive decoding machinery based on nucleic acids and proteins, and most likely the modern day system, has to satisfy certain geometrical constraints. The charged amino acyl and the peptidyl termini of successive adaptors have to be adjacent in space in order to satisfy the stereochemical requirements for amide bond formation. Simultaneously, the same adaptors have to recognize successive codons on the messenger. This translational complex has to be realized by components that obey nucleic acid conformational principles, stabilities, and specificities. This generalized condition greatly restricts the number of acceptable adaptor structures.

  13. Osseointegration of alumina bioceramic granules: A comparative experimental study

    NASA Astrophysics Data System (ADS)

    Rerikh, V. V.; Avetisyan, A. R.; Zaydman, A. M.; Anikin, K. A.; Bataev, V. A.; Nikulina, A. A.; Sadovoy, M. A.; Aronov, A. M.; Semantsova, E. S.

    2016-08-01

    To perform a comparative analysis of osseointegration of bioceramic alumina-based granules, hydroxyapatite-based granules, and deproteinized bone granules. The experiment was conducted on 52 adult male Kyoto-Wistar rats weighing 350 to 520 g. The animals were divided into five matched groups that differed only in the type of an implanted material. The granules were implanted in the lumbar vertebral bodies and in the distal right femur of each laboratory animal. Two months after surgery, the animals were euthanized, followed by tissue sampling for morphological studies. An examination of specimens from the groups with implanted alumina granules revealed the newly formed trabecular bone with remodeling signs. The bone tissue filled the intragranular space, tightly adhering to the granule surface. There was no connective tissue capsule on the border between bone tissue and alumina granules. Cylindrical bioceramic alumina-based granules with an open internal channel have a higher strength surpassing than that of analogs and the osseointegration ability close to that of hydroxyapatite and deproteinized bone granules.

  14. Comparative Study Between Wind and Photovoltaic (PV) Systems

    NASA Astrophysics Data System (ADS)

    Taha, Wesam

    This paper reviews two renewable energy systems; wind and photovoltaic (PV) systems. The common debate between the two of them is to conclude which one is better, in terms of cost and efficiency. Therefore, comparative study, in terms of cost and efficiency, is attempted. Regarding total cost of both, wind and PV systems, many parameters must be taken into consideration such as availability of energy (either wind or solar), operation and maintenance, availability of costumers, political influence, and the components used in building the system. The main components and parameters that play major role in determining the overall efficiency of wind systems are the wind turbine generator (WTG), gearbox and control technologies such as power, and speed control. On the other hand, in grid-connected PV systems (GCPVS), converter architecture along with maximum power point tracking (MPPT) algorithm and inverter topologies are the issues that affects the efficiency significantly. Cost and efficiency analyses of both systems have been carried out based on the statistics available till today and would be useful in the progress of renewable energy penetration throughout the world.

  15. Fungal biodegradation of anthracene-polluted cork: A comparative study.

    PubMed

    Jové, Patrícia; Olivella, Maria À; Camarero, Susana; Caixach, Josep; Planas, Carles; Cano, Laura; De Las Heras, Francesc X

    2016-01-01

    The efficiency of cork waste in adsorbing aqueous polycyclic aromatic hydrocarbons (PAHs) has been previously reported. Biodegradation of contaminated cork using filamentous fungi could be a good alternative for detoxifying cork to facilitate its final processing. For this purpose, the degradation efficiency of anthracene by three ligninolytic white-rot fungi (Phanerochaete chrysosporium, Irpex lacteus and Pleurotus ostreatus) and three non-ligninolytic fungi which are found in the cork itself (Aspergillus niger, Penicillium simplicissimum and Mucor racemosus) are compared. Anthracene degradation by all fungi was examined in solid-phase cultures after 0, 16, 30 and 61 days. The degradation products of anthracene by P. simplicissimum and I. lacteus were also identified by GC-MS and a metabolic pathway was proposed for P. simplicissimum. Results show that all the fungi tested degraded anthracene. After 61 days of incubation, approximately 86%, 40%, and 38% of the initial concentration of anthracene (i.e., 100 µM) was degraded by P. simplicissimum, P. chrysosporium and I. lacteus, respectively. The rest of the fungi degraded anthracene to a lesser extent (<30%). As a final remark, the results obtained in this study indicate that P. simplicissimum, a non-ligninolytic fungi characteristic of cork itself, could be used as an efficient degrader of PAH-contaminated cork. PMID:26540209

  16. The minds of gods: a comparative study of supernatural agency.

    PubMed

    Purzycki, Benjamin Grant

    2013-10-01

    The present work is the first study to systematically compare the minds of gods by examining some of the intuitive processes that guide how people reason about them. By examining the Christian god and the spirit-masters of the Tyva Republic, it first confirms that the consensus view of the Christian god's mind is one of omniscience with acute concern for interpersonal social behavior (i.e., moral behaviors) and that Tyvan spirit-masters are not as readily attributed with knowledge or concern of moral information. Then, it reports evidence of a moralization bias of gods' minds; American Christians who believe that God is omniscient rate God as more knowledgeable of moral behaviors than nonmoral information. Additionally, Tyvans who do not readily report pro- or antisocial behavior among the things that spirit-masters care about will nevertheless rate spirit-masters' knowledge and concern of moral information higher than nonmoral information. However, this knowledge is distributed spatially; the farther away from spirits' place of governance a moral behavior takes place, the less they know and care about it. Finally, the wider the breadth of knowledge Tyvans attribute to spirit-masters, the more they attribute moral concern for behaviors that transpire beyond their jurisdiction. These results further demonstrate that there is a significant gulf between expressed beliefs and intuitive religious cognition and provides evidence for a moralization bias of gods' minds. PMID:23891826

  17. Comparative Case Study of Two Biomedical Research Collaboratories

    PubMed Central

    Teasley, Stephanie D; Bhatnagar, Rishi

    2005-01-01

    Background Working together efficiently and effectively presents a significant challenge in large-scale, complex, interdisciplinary research projects. Collaboratories are a nascent method to help meet this challenge. However, formal collaboratories in biomedical research centers are the exception rather than the rule. Objective The main purpose of this paper is to compare and describe two collaboratories that used off-the-shelf tools and relatively modest resources to support the scientific activity of two biomedical research centers. The two centers were the Great Lakes Regional Center for AIDS Research (HIV/AIDS Center) and the New York University Oral Cancer Research for Adolescent and Adult Health Promotion Center (Oral Cancer Center). Methods In each collaboratory, we used semistructured interviews, surveys, and contextual inquiry to assess user needs and define the technology requirements. We evaluated and selected commercial software applications by comparing their feature sets with requirements and then pilot-testing the applications. Local and remote support staff cooperated in the implementation and end user training for the collaborative tools. Collaboratory staff evaluated each implementation by analyzing utilization data, administering user surveys, and functioning as participant observers. Results The HIV/AIDS Center primarily required real-time interaction for developing projects and attracting new participants to the center; the Oral Cancer Center, on the other hand, mainly needed tools to support distributed and asynchronous work in small research groups. The HIV/AIDS Center’s collaboratory included a center-wide website that also served as the launch point for collaboratory applications, such as NetMeeting, Timbuktu Conference, PlaceWare Auditorium, and iVisit. The collaboratory of the Oral Cancer Center used Groove and Genesys Web conferencing. The HIV/AIDS Center was successful in attracting new scientists to HIV/AIDS research, and members

  18. Comparative bioequivalence study of three formulations of enrofloxacin in sheep.

    PubMed

    El-Banna, H A; Goudah, A; El-Zorba, H

    2011-04-01

    A comparative pharmacokinetic study of three enrofloxacin injectable solutions was carried out in six healthy Barky rams after intramuscular injection according to a single dose, randomized, crossover experimental design. The three formulations were enrofloxacin 10% (Baytril(®)), enrofloxacin 10% plus bromhexine 1% (Mucotryl(®)) and enrofloxacin 10 % solution without bromhexine (Mucotryl without bromhexine). The three formulations were given a single intramuscular dose at a dose rate of 5 mg kg(-1) b.wt. The concentrations of the drug in the serum were measured using high-performance liquid chromatography (HPLC) with fluorescence detection. The results indicate that there were no significant differences between the distribution rate constant (k(ab)) and distribution half-life (t(1/2ab)), the maximum serum concentration (C(max)) and the time to peak concentration (T(max)) between Baytril and the other two formulations. There were significant differences between the elimination half life (t(1/2el)) and elimination rate constant (k(el)), for Baytril and enrofloxacin (the exact formulation of Mucotryl without bromhexine). Enrofloxacin was rapidly absorbed following IM administration of 5 mg kg(-1) b. wt. The peak serum concentrations (C(max)) were 2.83, 2.45 and 3.12 µg ml(-1) and were attained at (t(max)) 1.15, 1.41 and 1.26 hours when given Mucotryl, Baytril and enrofloxacin (the exact formulation of Mucotryl without bromhexine) to sheep, respectively. The injectable formulations investigated were bioequivalent after their intramuscular injection to sheep at recommended dose rate. As our results showed that, values of T(max), C(max) and AUC (Area under time curve concentration) determined for both Baytril, Mucotryl, and enrofloxacin (the exact formulation of Mucotryl without bromhexine ( reference ant test products) are within the acceptable range of 0.80-1.20, this means that the tested products product under investigation was bio-equivalent. These findings

  19. Modeller's attitude in catchment modelling: a comparative study

    NASA Astrophysics Data System (ADS)

    Battista Chirico, Giovanni

    2010-05-01

    Ten modellers have been invited to predict, independently from each other, the discharge of the artificial Chicken Creek catchment in North-East Germany for simulation period of three years, providing them only soil texture, terrain and meteorological data. No data concerning the discharge or other sources of state variables and fluxes within the catchment have been provided. Modellers had however the opportunity to visit the experimental catchment and inspect areal photos of the catchments since its initial development stage. This study has been a unique comparative study focussing on how different modellers deal with the key issues in predicting the discharge in ungauged catchments: 1) choice of the model structure; 2) identification of model parameters; 3) identification of model initial and boundary conditions. The first general lesson learned during this study was that the modeller is just part of the entire modelling process and has a major bearing on the model results, particularly in ungauged catchments where there are more degrees of freedom in making modelling decisions. Modellers' attitudes during the stages of the model implementation and parameterisation have been deeply influenced by their own experience from previous modelling studies. A common outcome was that modellers have been mainly oriented to apply process-based models able to exploit the available data concerning the physical properties of the catchment and therefore could be more suitable to cope with the lack of data concerning state variables or fluxes. The second general lesson learned during this study was the role of dominant processes. We believed that the modelling task would have been much easier in an artificial catchment, where heterogeneity were expected to be negligible and processes simpler, than in catchments that have evolved over a longer time period. The results of the models were expected to converge, and this would have been a good starting point to proceed for a model

  20. Does interprofessional simulation increase self-efficacy: a comparative study

    PubMed Central

    Watters, Colm; Reedy, Gabriel; Ross, Alastair; Morgan, Nicola J; Handslip, Rhodri; Jaye, Peter

    2015-01-01

    Objectives In this work, we have compared uniprofessional and interprofessional versions of a simulation education intervention, in an attempt to understand more about whether it improves trainees’ self-efficacy. Background Interprofessionalism has been climbing the healthcare agenda for over 50 years. Simulation education attempts to create an environment for healthcare professionals to learn, without potential safety risks for patients. Integrating simulation and interprofessional education can provide benefits to individual learners. Setting The intervention took place in a high-fidelity simulation facility located on the campus of a large urban hospital. The centre provides educational activities for an Academic Health Sciences Centre. Approximately 2500 staff are trained at the centre each year. Participants One hundred and fifteen nurses and midwives along with 156 doctors, all within the early years of their postgraduate experience participated. All were included on the basis of their ongoing postgraduate education. Methods Each course was a one-day simulation course incorporating five clinical and one communication scenarios. After each a facilitated debriefing took place. A mixed methods approach utilised precourse and postcourse questionnaires measuring self-efficacy in managing emergency situations, communication, teamwork and leadership. Results Thematic analysis of qualitative data showed improvements in communication/teamwork and leadership, for doctors and nurses undergoing simulation training. These findings were confirmed by statistical analysis showing that confidence ratings improved in nurses and doctors overall (p<0.001). Improved outcomes from baseline were observed for interprofessional versus uniprofessional trained nurses (n=115; p<0.001). Postcourse ratings for doctors showed that interprofessional training was significantly associated with better final outcomes for a communication/teamwork dimension (n=156; p<0.05). Conclusions This

  1. Comparative study of novel endovascular treatment techniques for intracranial aneurysms

    NASA Astrophysics Data System (ADS)

    Cantón, Gádor; Lasheras, Juan C.; Levy, David I.; Sparks, Steven R.

    2002-11-01

    Intracranial aneurysms are life-threatening vascular lesions, which are potentially treatable to avoid the consequences of their rupture. Current treatments, either surgical or endovascular, are all guided to reduce the hemodynamic forces acting on the aneurysm wall in an effort to minimize the risk of rupture. Surgical clipping is still the most used technique to treat this type of aneurysm but there is a continued demand for less invasive approaches. This has led to the development of several endovascular techniques. We report here a comparative study of the reduction in the hemodynamic stresses and the modification of the flow in the parent vessel resulting from the use of three different techniques. The first one consists of endosaccular packing with platinum coils (GDC, Target Therapeutics), which is already widely used but its long-term efficacy has not yet been determined. The second one consists of the embolization of the aneurismal sac with Onyx, a polymer which hardens when in contact with the blood (being developed by Micro Therapeutics, Inc.). The third one involves the packing of the sac with hydrocoils, platinum wires coated with a gel which quickly hydrates when in contact with blood (developed by MicroVention). A Digital Particle Image Velocimetry (DPIV) system is used to measure in vitro the velocity field inside a model of an ACOM aneurysm (an aneurysm forming in the anterior communicating artery). Physiological accurate pulsatile flow conditions are input to the arterial model through a programmable pump. The measurements show that although all treatment techniques lead to a reduction in both normal and tangential shear stresses on the aneurismal sac, each one of them also leads to different modifications of the flow in the parent vessel which may have consequences related to potential for clotting. Comparison of the untreated aneurysm with the above three treated cases also showed that the characteristics of the wall shear stresses on the parent

  2. Comparative Study of Non-Enveloped Icosahedral Viruses Size

    PubMed Central

    Nikitin, Nikolai; Trifonova, Ekaterina; Evtushenko, Evgeniy; Kirpichnikov, Mikhail; Atabekov, Joseph; Karpova, Olga

    2015-01-01

    Now, as before, transmission electron microscopy (TEM) is a widely used technique for the determination of virions size. In some studies, dynamic light scattering (DLS) has also been applied for this purpose. Data obtained by different authors and using different methods could vary significantly. The process of TEM sample preparation involves drying on the substrate, which can cause virions to undergo morphology changes. Therefore, other techniques should be used for measurements of virions size in liquid, (i.e. under conditions closer to native). DLS and nanoparticle tracking analysis (NTA) provide supplementary data about the virions hydrodynamic diameter and aggregation state in liquid. In contrast to DLS, NTA data have a higher resolution and also are less sensitive to minor admixtures. In the present work, the size of non-enveloped icosahedral viruses of different nature was analyzed by TEM, DLS and NTA: the viruses used were the encephalomyocarditis virus (animal virus), and cauliflower mosaic virus, brome mosaic virus and bean mild mosaic virus (plant viruses). The same, freshly purified, samples of each virus were used for analysis using the different techniques. The results were compared with earlier published data and description databases. DLS data about the hydrodynamic diameter of bean mild mosaic virus, and NTA data for all examined viruses, were obtained for the first time. For all virus samples, the values of size obtained by TEM were less than virions sizes determined by DLS and NTA. The contribution of the electrical double layer (EDL) in virions hydrodynamic diameter was evaluated. DLS and NTA data adjusted for EDL thickness were in better agreement with TEM results. PMID:26545232

  3. Comparative study on Kasisa Bhasma prepared by two different methods

    PubMed Central

    Rajput, Dhirajsingh; Tekale, G. S.; Patgiri, BJ

    2011-01-01

    Preparation of bhasma (calcined powder of metal/minerals) includes various processing steps like purification (Shodhana), levigation (Bhavana),calcinations cycle(Marana), improving quality and removing blemishes (Amritikarana) etc, processing of bhasma aims at formation of herbo-mineral complex molecule which can act in minimal dosage, palatable, easy for assimilation, highly efficacious with minimal or no complication. Although the most important equipment mentioned for Marana i.e. cow dung cakes and some type of woods are not only difficult to collect but also expensive and create pollution during puta and it's difficult task to give controlled heat in traditional method. Hence, a Modified Portable Bhasma Nirman Yantra (MPBNY) was prepared for puta (equipment for calcination) procedure which is easy to handle, portable and facilitate to supply controlled heat. A comparative study was conducted on Kasisa Bhasma prepared by traditional method and by using MPBNY with special reference to physico-chemical properties. The prepared Kasisa Bhasma was subjected to modern analytical parameters such as A.A.S. (Atomic Absorption Spectroscopy), X.R.D. (X-ray Diffraction) and Ayurvedic parameters eg. Rekhapurnatva (bhasma should enters in between lines of finger), Varitaratva (bhasma should float on the surface of water), Niramlatva (bitter less), Apunarbhava (bhasma should not regain its metallic nature after strong heating with jiggery, Abrus precatorius linn., honey and ghee) and Niruttha (bhasma should not regain its metallic nature after strong heating with silver). It was observed that Kasisa Bhasma of both methods possesses similar organoleptic as well as physico-chemical properties. PMID:23284208

  4. Impact comparative study of phone carcasses behavior by FEM

    NASA Astrophysics Data System (ADS)

    Constantin, Cărăuşu; Plăvănescu, Simona; Dumitru, Nedelcu

    2015-07-01

    A constant concern of scientific research is based on plastics replace with biodegradable materials that reduce the adverse impact of waste on the environment. A biodegradable material that arouses interest lately is Arboform which is made of lignin, a component of wood and woody plants. Replacing plastic with Arboform in carrying components of products requires technical and economic studies on the implications of such replacement. Numerical simulation methods are a fast and economical way of analyzing the behavior of a product in various mechanical, thermal, electromagnetic and so on. The paper presents comparative results of numerical simulation using the software package SolidWorks impact behavior through the “Drop Test” of half shells made of High Density Polyethylene (HDPE) and of the Arboform LV3 Nature. Simulation watched the half-carcass behavior in three cases of accidental impact, “head”, “corner” and the “back side”. We analyzed the size and location of the maximum voltage and maximum deformation resulting from impact. Simulations have shown for all three cases a maximum voltage increase when using Arboform to use PEDH 93% for impact “forward” and “corner” and only 48.77% “back side” impact. If the maximum displacement, it increasing from carcasses of Arboform 4% for impact “head” and 6% for impact “corner”, but fell by 2.7% for the “back side” impact. The significant increase of stress can be attributed to the higher density of Arboform to PEDH, which led to different weights of the two half-carcasses.

  5. Comparative study on Kasisa Bhasma prepared by two different methods.

    PubMed

    Rajput, Dhirajsingh; Tekale, G S; Patgiri, Bj

    2011-10-01

    Preparation of bhasma (calcined powder of metal/minerals) includes various processing steps like purification (Shodhana), levigation (Bhavana),calcinations cycle(Marana), improving quality and removing blemishes (Amritikarana) etc, processing of bhasma aims at formation of herbo-mineral complex molecule which can act in minimal dosage, palatable, easy for assimilation, highly efficacious with minimal or no complication. Although the most important equipment mentioned for Marana i.e. cow dung cakes and some type of woods are not only difficult to collect but also expensive and create pollution during puta and it's difficult task to give controlled heat in traditional method. Hence, a Modified Portable Bhasma Nirman Yantra (MPBNY) was prepared for puta (equipment for calcination) procedure which is easy to handle, portable and facilitate to supply controlled heat. A comparative study was conducted on Kasisa Bhasma prepared by traditional method and by using MPBNY with special reference to physico-chemical properties. The prepared Kasisa Bhasma was subjected to modern analytical parameters such as A.A.S. (Atomic Absorption Spectroscopy), X.R.D. (X-ray Diffraction) and Ayurvedic parameters eg. Rekhapurnatva (bhasma should enters in between lines of finger), Varitaratva (bhasma should float on the surface of water), Niramlatva (bitter less), Apunarbhava (bhasma should not regain its metallic nature after strong heating with jiggery, Abrus precatorius linn., honey and ghee) and Niruttha (bhasma should not regain its metallic nature after strong heating with silver). It was observed that Kasisa Bhasma of both methods possesses similar organoleptic as well as physico-chemical properties. PMID:23284208

  6. The Neurobehavioural Evaluation in Schizophrenics: A Comparative Study

    PubMed Central

    Ilamkar, Kamini Ramdas

    2013-01-01

    Background: The simple reaction time task assesses the ability of the subject to respond to an external cue and to retrieve a reward. The reaction time provides an indirect index of the processing capability of the central nervous system and a simple means to the determined sensory and the motor performances, which is a neurobehavioural evaluation. A general slowness in the latency in the reaction time tasks and a disengagement deficit in the visual and the hearing oriented tasks were seen in schizophrenics. Aims: In order to clarify the feature of the attention disorders in schizophrenia, a simple reaction time task was given to schizophrenics. Methods and Materials: Schizophrenics (34 males and 20 females, n=54) and healthy controls (40 males and 21 females, n=61) with a mean age of 35±7, who were individually matched for gender and age, were included in the study, by using a response analyser to evaluate the reaction time. Statistical analysis: The performances were expressed in mean ± standard deviation of the reaction time by using the unpaired ‘t’ test. Results and Conclusions: The schizophrenic patients performed poorer than the healthy controls, which indicated a difficulty in sustaining attention and this was statistically very highly significant (p<0.000). The results suggested that the schizophrenics showed inattentiveness in the clinical settings and an emotional disturbance in interpersonal situations. The increased reaction time as compared to that in healthy controls, might be due to the impairment of the psychomotor poverty, disorganization and reality distortion which were associated with the deficits in the cortical neurological functions, such as planning, coordination and sequencing of the motor acts, which showed a greater involvement of the frontal lobe and temporal lobe dysfunction. PMID:23449931

  7. Comparative study on sound production in different Holocentridae species

    PubMed Central

    2011-01-01

    Background Holocentrids (squirrelfish and soldierfish) are vocal reef fishes whose calls and sound-producing mechanisms have been studied in some species only. The present study aims to compare sound-producing mechanisms in different Holocentridae genera (Holocentrus, Myripristis, Neoniphon, Sargocentron) from separate regions and, in some cases, at different developmental stages. An accurate comparison was made by recording six species while being hand-held, by observing TEM) the sonic muscles and by dissections of the sound-producing mechanism. Results In all these species, calls presented harmonics, their dominant frequency was between 80 and 130 Hz and they were composed of trains of 4 to 11 pulses with gradual increasing periods towards the end of the call. In each case, the calls did not provide reliable information on fish size. The sounds were produced by homologous fast-contracting sonic muscles that insert on articulated ribs whose proximal heads are integrated into the swimbladder: each pulse is the result of the back and forth movements of the ribs. Small differences in the shape of the oscillograms of the different species could be related to the number of ribs that are involved in the sound-producing mechanism. These fish species are able to make sounds as soon as they settle on the reef, when they are 40 days old. Comparison between Neoniphon from Madagascar and from Rangiroa in French Polynesia showed a new, unexpected kind of dialect involving differences at the level of pulse distribution. Neoniphon calls were characterised by a single pulse that was isolated at the beginning of the remaining train in Madagascar whereas they did not show any isolated single pulses at the beginning of the call in Rangiroa. Conclusion This family cannot use the acoustic fundamental frequencies (or pulse periods) of grunts to infer the size of partners. Pulse duration and number of pulses are statistically related to fish size. However, these characteristics are

  8. Cell Kinetic and Histomorphometric Analysis of Microgravitational Osteopenia: PARE.03B

    NASA Technical Reports Server (NTRS)

    Roberts, W. Eugene; Garetto, Lawrence P.

    1997-01-01

    The final report includes the hypotheses and specific aims of the project as well as summaries of the experimental findings. Descriptions of several figures that are not included in the report are also presented. A list of publications that resulted from the research is also given. The three experimental summaries are entitled: (1) Pre-flight Experiment to compare 5-Bromo-2'Deoxyuridine (BrdU) Immunohistochemistry and 3H-Thymidine (3HT) Autoradiography; (2) Recovery of Osteoblast Histogenesis in Rat Periodontal Ligament following a 9-day Spaceflight (PARE.03); and (3) Analysis of Mandibular Condyles from PARE.03 Flight Experiment.

  9. Digital photogrammetry and histomorphometric assessment of the effect of non-coherent light (light-emitting diode) therapy (λ640 ± 20 nm) on the repair of third-degree burns in rats.

    PubMed

    Neves, Silvana Maria Véras; Nicolau, Renata Amadei; Filho, Antônio Luiz Martins Maia; Mendes, Lianna Martha Soares; Veloso, Ana Maria

    2014-01-01

    Recent studies have demonstrated the efficacy of coherent light therapy from the red region of the electromagnetic spectrum on the tissue-healing process. This study analysed the effect of non-coherent light therapy (light-emitting diode-LED) with or without silver sulfadiazine (sulpha) on the healing process of third-degree burns. In this study, 72 rats with third-degree burns were randomly divided into six groups (n = 12): Gr1 (control), Gr2 (non-contact LED), Gr3 (contact LED), Gr4 (sulfadiazine), Gr5 (sulfadiazine + non-contact LED) and Gr6 (sulfadiazine + contact LED). The groups treated with LED therapy received treatment every 48 h (λ = 640 ± 20 nm, 110 mW, 16 J/cm(2); 41 s with contact and 680 s without contact). The digital photometric and histomorphometric analyses were conducted after the burn occurred. The combination of sulpha and LED (contact or non-contact) improved the healing of burn wounds. These results demonstrate that the combination of silver sulfadiazine with LED therapy (λ = 640 ± 20 nm, 4 J/cm(2), without contact) improves healing of third-degree burn wounds, significantly reduces the lesion area and increases the granulation tissue, increases the number of fibroblasts, promotes collagen synthesis and prevents burn infections by accelerating recovery. PMID:23584731

  10. A comparative study about learning styles preferences of two cultures

    NASA Astrophysics Data System (ADS)

    Kutay, Huban

    From an anthropologist's (Maddock, 1981) point of view, "science and science education are cultural enterprises which form a part of the wider cultural matrix of society and educational considerations concerning science must be made in the light of this wider perspective" (p.10). In addition, Spindler (1987) states that teaching science is considered cultural transmission while, Wolcott (1991) focuses on learning science as culture acquisition. In these statements, culture is defined as "an ordered system of meaning and symbols, in terms of which social interaction takes place" (Geertz, 1973). Thus, learning and culture are a partnership. Jones and Fennimore (1990) state: "Every culture brings habits of thought, resources, and context, which have built into them vehicles that promote learning and inquiry. Accordingly, children of any culture can and should have curriculum and instructional practices that draw from that culture." (p.16). Unfortunately, even though this statement is probably accurate, most schools still use the same curriculum, instructional methods, and assessment strategies for all students regardless of their differences in learning styles. The purpose of this study is to identify the relationship between students' learning styles and their culture. This is a correlational study. Does culture limit or expand the learning of individuals? For this study Turkish students who graduated from a Turkish high school and undertook undergraduate education in the United States or finished their undergraduate education in Turkey and pursued graduate education in the United States were identified. These Turkish subjects were compared to American college students through learning styles data and anxiety levels as cultural markers. To identify individuals' learning styles we used the Building Excellence (BE) instrument, which is an adult version of The Learning Style Inventory by Dunn, and Rundle (1996.1997, 1998, 1999, and 2000). BE assesses twenty four

  11. Comparative study of different waste biomass for energy application.

    PubMed

    Motghare, Kalyani A; Rathod, Ajit P; Wasewar, Kailas L; Labhsetwar, Nitin K

    2016-01-01

    Biomass is available in many varieties, consisting of crops as well as its residues from agriculture, forestry, and the agro-industry. These different biomass find their way as freely available fuel in rural areas but are also responsible for air pollution. Emissions from such solid fuel combustion to indoor, regional and global air pollution largely depend on fuel types, combustion device, fuel properties, fuel moisture, amount of air supply for combustion and also on climatic conditions. In both economic and environment point of view, gasification constitutes an attractive alternative for the use of biomass as a fuel, than the combustion process. A large number of studies have been reported on a variety of biomass and agriculture residues for their possible use as renewable fuels. Considering the area specific agriculture residues and biomass availability and related transportation cost, it is important to explore various local biomass for their suitability as a fuel. Maharashtra (India) is the mainstay for the agriculture and therefore, produces a significant amount of waste biomass. The aim of the present research work is to analyze different local biomass wastes for their proximate analysis and calorific value to assess their potential as fuel. The biomass explored include cotton waste, leaf, soybean waste, wheat straw, rice straw, coconut coir, forest residues, etc. mainly due to their abundance. The calorific value and the proximate analysis of the different components of the biomass helped in assessing its potential for utilization in different industries. It is observed that ash content of these biomass species is quite low, while the volatile matter content is high as compared to Indian Coal. This may be appropriate for briquetting and thus can be used as a domestic fuel in biomass based gasifier cook stoves. Utilizing these biomass species as fuel in improved cook-stove and domestic gasifier cook-stoves would be a perspective step in the rural energy and

  12. PROSPECTIVE RANDOMIZED STUDY COMPARING TWO ANESTHETIC METHODS FOR SHOULDER SURGERY

    PubMed Central

    Ikemoto, Roberto Yukio; Murachovsky, Joel; Prata Nascimento, Luis Gustavo; Bueno, Rogerio Serpone; Oliveira Almeida, Luiz Henrique; Strose, Eric; de Mello, Sérgio Cabral; Saletti, Deise

    2015-01-01

    Objective: To evaluate the efficacy of suprascapular nerve block in combination with infusion of anesthetic into the subacromial space, compared with interscalene block. Methods: Forty-five patients with small or medium-sized isolated supraspinatus tendon lesions who underwent arthroscopic repair were prospectively and comparatively evaluated through random assignation to three groups of 15, each with a different combination of anesthetic methods. The efficacy of postoperative analgesia was measured using the visual analogue scale for pain and the analgesic, anti-inflammatory and opioid drug consumption. Inhalation anesthetic consumption during surgery was also compared between the groups. Results: The statistical analysis did not find any statistically significant differences among the groups regarding anesthetic consumption during surgery or postoperative analgesic efficacy during the first 48 hours. Conclusion: Suprascapular nerve block with infusion of anesthetic into the subacromial space is an excellent alternative to interscalene block, particularly in hospitals in which an electrical nerve stimulating device is unavailable. PMID:27022569

  13. Psychiatric Diagnostic Interviews for Children and Adolescents: A Comparative Study

    ERIC Educational Resources Information Center

    Angold, Adrian; Erkanli, Alaattin; Copeland, William; Goodman, Robert; Fisher, Prudence W.; Costello, E. Jane

    2012-01-01

    Objective: To compare examples of three styles of psychiatric interviews for youth: the Diagnostic Interview Schedule for Children (DISC) ("respondent-based"), the Child and Adolescent Psychiatric Assessment (CAPA) ("interviewer-based"), and the Development and Well-Being Assessment (DAWBA) ("expert judgment"). Method: Roughly equal numbers of…

  14. Comparative Study of Student Support Services of UKOU and SLOU

    ERIC Educational Resources Information Center

    Gujjar, Aijaz Ahmed; Choudhry, Bushra Naoreen; Choudhry, Amtul Hafeez

    2008-01-01

    This paper attempts to compare the availability, quality, similarities and differences of students' support services in United Kingdom Open University (UKOU) and Sri Lanka Open University (SLOU) and also to identify and enlist the deficiencies that SLOU students are facing in the student support services. To get the desired end four hundred…

  15. Automated Essay Scoring versus Human Scoring: A Comparative Study

    ERIC Educational Resources Information Center

    Wang, Jinhao; Brown, Michelle Stallone

    2007-01-01

    The current research was conducted to investigate the validity of automated essay scoring (AES) by comparing group mean scores assigned by an AES tool, IntelliMetric [TM] and human raters. Data collection included administering the Texas version of the WriterPlacer "Plus" test and obtaining scores assigned by IntelliMetric [TM] and by human…

  16. Reforming Teaching Globally. Oxford Studies in Comparative Education

    ERIC Educational Resources Information Center

    Tatto, Maria Teresa, Ed.

    2007-01-01

    This book seeks to raise the discussion of globalisation's effects on teacher education, development and work, and its reforms and institutions, to a more theoretical and analytical level, and to provide specific examples in the comparative tradition to illustrate teacher policy in the context of education systems' widespread variability and…

  17. Inmate Movements and Prison Uprisings: A Comparative Study.

    ERIC Educational Resources Information Center

    Pederson, William D.

    1978-01-01

    Fifteen "criminal" and political uprisings from inmate movements in American, Soviet, and German prisons are compared. Conditions of deprivation related to prison violence are linked with attitudinal, structural, and temporal factors. Findings are that inmate movements are a rare phenomenon in comparison with isolated prison uprisings. (KC)

  18. Social Cartography: A New Methodology for Comparative Studies.

    ERIC Educational Resources Information Center

    Liebman, Martin; Paulston, Rolland

    Comparative educators can enhance research by developing and including in their research findings a cognitive map to show perceptions of how knowledge claims interrelate. Three research relationships utilize different methodologies: (1) the researcher objectifies the phenomena; (2) the researcher position is preferential to the research object but…

  19. Study of the Comparability of the WISC and the WAIS

    ERIC Educational Resources Information Center

    Simpson, Robert L.

    1970-01-01

    Subtests of the two instruments were administered in randomized order to 120 16 year old students. Analysis of variance revealed higher WAIS than WISC Verbal (p is less than .001), Performance (p is less than .01), and Full Scales (p is less than .001) IQs. The WISC and WAIS are not comparable for below average intelligence students. Reprints from…

  20. Parental Bereavement after Suicide and Accident: A Comparative Study.

    ERIC Educational Resources Information Center

    Seguin, Monique; And Others

    1995-01-01

    Compares differences in the bereavement process for 30 survivors of suicide versus 30 survivors of car accidents. Indicates suicide survivors were more depressed than accident survivors at the first measure but not at the second measure. Survivors of suicide experienced greater feelings of shame and had experienced more life events after the death…

  1. A Corpus-Based Comparative Study of "Learn" and "Acquire"

    ERIC Educational Resources Information Center

    Yang, Bei

    2016-01-01

    As an important yet intricate linguistic feature in English language, synonymy poses a great challenge for second language learners. Using the 100 million-word British National Corpus (BNC) as data and the software Sketch Engine (SkE) as an analyzing tool, this article compares the usage of "learn" and "acquire" used in natural…

  2. A Comparative Study of Standard-Setting Methods.

    ERIC Educational Resources Information Center

    Livingston, Samuel A.; Zieky, Michael J.

    1989-01-01

    The borderline group standard-setting method (BGSM), Nedelsky method (NM), and Angoff method (AM) were compared, using reading scores for 1,948 and mathematics scores for 2,191 sixth through ninth graders. The NM and AM were inconsistent with the BGSM. Passing scores were higher where students were more able. (SLD)

  3. Teaching Organic Synthesis: A Comparative Case Study Approach

    ERIC Educational Resources Information Center

    Vosburg, David A.

    2008-01-01

    In this course, students encounter reactions and mechanisms in the context of landmark syntheses of biologically important molecules. Students closely examine pairs of syntheses of related or identical molecules to facilitate their appreciation for synthetic strategy. They then write short, creative papers that critically compare the two synthetic…

  4. Understanding Organizational Change: A Comparative Study of Multifaceted Interventions.

    ERIC Educational Resources Information Center

    Pasmore, William A.; King, Donald C.

    1978-01-01

    Investigates the differential impacts of sociotechnical systems, job redesign, and survey-feedback interventions on a wide array of attitudinal and performance measures in comparable units of an organization. Attitudinal effects were quite similar; however, only the sociotechnical system intervention resulted in major productivity improvements and…

  5. The Comparative Study of First and Second Language Development.

    ERIC Educational Resources Information Center

    Clahsen, Harald

    1990-01-01

    Compares different approaches to first- and second-language development. It is argued that the observed differences between first- and (adult) second-language acquisition can be accounted for by assuming that adult second-language learners can not use Universal Grammar principles as a learning device in the same way that first-language learners…

  6. Comparative Actions of Barbiturates Studied by Pollen Grain Germination.

    ERIC Educational Resources Information Center

    Kordan, Herbert A.; Mumford, Pauline M.

    1979-01-01

    Describes a simple experimental system whereby the comparative actions of long, medium, and short-acting barbiturates can be demonstrated in a relatively short period of time under optical microscopy using pollen grains as the biological test or assay system. (Author/HM)

  7. Vocation, Motivation and Approaches to Learning: A Comparative Study

    ERIC Educational Resources Information Center

    Arquero, Jose Luis; Fernández-Polvillo, Carmen; Hassall, Trevor; Joyce, John

    2015-01-01

    Purpose: The individual characteristics of students can have a strong influence on the success of the adopted innovations in terms of their transferability and sustainability. The purpose of this paper is to compare the motivations and approaches to learning on degrees with differing vocational components. Design/methodology/approach:…

  8. A mechanical and histomorphometric analysis of bone bonding by hydroxyapatite-coated strain gages.

    PubMed

    Wilson, D L; Szivek, J A; Anderson, P L; Miera, V L; Battraw, G A

    1998-01-01

    Identification of the strains controlling bone remodeling is important for determining ways to prevent bone loss due to load deprivation, or implant placement. Long-term monitoring of strains can potentially provide the best information. Glues are resorbed within 2-3 weeks. Two formulations of microcrystalline hydroxyapatite (HA) were used to attach strain gages to rat femora to assess their long-term in vivo strain measurement capability. Seven male rats received HA-coated gages, and 2 animals underwent a sham procedure. The gages were prepared using a published technique and placed on the antero-lateral aspect of the left femora. After 6-7 weeks, the animals were euthanized and both femora explanted. Gages were attached to the right femora with cyanoacrylate. All femora were tested in cantilever bending, then embedded, sectioned, and stained with mineralized bone stain. The undecalcified sections were examined using transmitted and ultraviolet light microscopy. Mechanical testing showed one HA formulation provided 70-100% bonding. Histology showed intimate contact between the gage and bone surface. Histomorphometry indicated increased bone activity under the gage compared to the remaining bone, the controls, and the shams. The results indicate that microcrystalline HAs bond to bone quickly and can allow long term in vivo measurements. PMID:9659635

  9. Histomorphometric and microchemical characterization of maturing dental enamel in rats fed a boron-deficient diet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Few reports are available in the literature on enamel formation under nutritional deficiencies. Continuously erupting rodent incisors have considerable potential to serve as a model system for amelogenesis. Thus, we performed a study to determine the effects of boron (B) deficiency on the maturing d...

  10. Comparative study of icy patches on comet nuclei

    NASA Astrophysics Data System (ADS)

    Oklay, Nilda; Pommerol, Antoine; Barucci, Maria Antonietta; Sunshine, Jessica; Sierks, Holger; Pajola, Maurizio

    2016-07-01

    Cometary missions Deep Impact, EPOXI and Rosetta investigated the nuclei of comets 9P/Tempel 1, 103P/Hartley 2 and 67P/Churyumov-Gerasimenko respectively. Bright patches were observed on the surfaces of each of these three comets [1-5]. Of these, the surface of 67P is mapped at the highest spatial resolution via narrow angle camera (NAC) of the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS, [6]) on board the Rosetta spacecraft. OSIRIS NAC is equipped with twelve filters covering the wavelength range of 250 nm to 1000 nm. Various filters combinations are used during surface mapping. With high spatial resolution data of comet 67P, three types of bright features were detected on the comet surface: Clustered, isolated and bright boulders [2]. In the visible spectral range, clustered bright features on comet 67P display bluer spectral slopes than the average surface [2, 4] while isolated bright features on comet 67P have flat spectra [4]. Icy patches observed on the surface of comets 9P and 103P display bluer spectral slopes than the average surface [1, 5]. Clustered and isolated bright features are blue in the RGB composites generated by using the images taken in NIR, visible and NUV wavelengths [2, 4]. This is valid for the icy patches observed on comets 9P and 103P [1, 5]. Spectroscopic observations of bright patches on comets 9P and 103P confirmed the existence of water [1, 5]. There were more than a hundred of bright features detected on the northern hemisphere of comet 67P [2]. Analysis of those features from both multispectral data and spectroscopic data is an ongoing work. Water ice is detected in eight of the bright features so far [7]. Additionally, spectroscopic observations of two clustered bright features on the surface of comet 67P revealed the existence of water ice [3]. The spectral properties of one of the icy patches were studied by [4] using OSIRIS NAC images and compared with the spectral properties of the active regions observed

  11. Cell Kinetic and Histomorphometric Analysis of Microgravitational Osteopenia: PARE.03B

    NASA Technical Reports Server (NTRS)

    Roberts, W. Eugene; Garetto, Lawrence P.

    1998-01-01

    Previous methods of identifying cells undergoing DNA synthesis (S-phase) utilized 3H-thymidine (3HT) autoradiography. 5-Bromo-2'-deoxyuridine (BrdU) immunohistochemistry is a nonradioactive alternative method. This experiment compared the two methods using the nuclear volume model for osteoblast histogenesis in two different embedding media. Twenty Sprague-Dawley rats were used, with half receiving 3HT (1 micro-Ci/g) and the other half BrdU (50 micro-g/g). Condyles were embedded (one side in paraffin, the other in plastic) and S-phase nuclei were identified using either autoradiography or immunohistochemistry. The fractional distribution of preosteoblast cell types and the percentage of labeled cells (within each cell fraction and label index) were calculated and expressed as mean +/- standard error. Chi-Square analysis showed only a minor difference in the fractional distribution of cell types. However, there were,significant differences (p less than 0.05) by ANOVA, in the nuclear labeling of specific cell types. With the exception of the less-differentiated A+A' cells, more BrdU label was consistently detected in paraffin than in plastic-embedded sections. In general, more nuclei were labeled with 3H-thymidine than with BrdU in both types of embedding media (Fig 2.). Labeling index data (labeled cells/total cells sampled x 100) indicated that BrdU in paraffin, but not plastic gave the same results as 3HT in either embedding method. Thus, we conclude that the two labeling methods do not yield the same results.

  12. Cell Kinetic and Histomorphometric Analysis of Microgravitational Osteopenia: PARE.03B

    NASA Technical Reports Server (NTRS)

    Roberts, W. Eugene; Garetto, Lawrence P.

    1998-01-01

    Previous methods of identifying cells undergoing DNA synthesis (S-phase) utilized H-3 thymidine (3HT) autoradiography. 5-Bromo-2'-deoxyuridine (BrdU) immunohistochemistry is a nonradioactive alternative method. This experiment compared the two methods using the nuclear volume model for osteoblast histogenesis in two different embedding media. Twenty Sprague-Dawley rats were used, with half receiving 3HT (1 micro Ci/g) and the other half BrdU (50 microgram/g). Condyies were embedded (one side in paraffin, the other in plastic) and S-phase nuclei were identified using either autoradiography or immunohistochemistry. The fractional distribution of preosteoblast cell types and the percentage of labeled cells (within each cell fraction and label index) were calculated and expressed as mean q standard error. Chi-Square analysis showed only a minor difference in the fractional distribution of cell types. However, there were significant differences (p less than 0.05) by ANOVA, in the nuclear labeling of specific cell types. With the exception of the less-differentiated A+A'cells, more BrdU label was consistently detected in paraffin than in plastic-embedded sections. In general, more nuclei were labeled with 3H-thymidine than with BrdU in both types of embedding media. Labeling index data (labeled cells/total cells sampled x 100) indicated that BrdU in paraffin, but not plastic gave the same results as 3HT in either embedding method. Thus, we conclude that the two labeling methods do not yield the same results for the nuclear volume model and that embedding media is an important factor whenusing BrdU. As a result of this work, 3HT was chosen for used in the PARE.03 flight experiments.

  13. Ultraviolet radiation penetrating vehicle glass: a field based comparative study

    NASA Astrophysics Data System (ADS)

    Kimlin, M. G.; Parisi, A. V.

    1999-04-01

    The solar UV transmitted through automobile glass was measured in the field in two cars using a spectroradiometer. The two cars were identical except that one of the cars had all of the windows (except the windshield) tinted. The measured spectral erythemal UV on a horizontal plane with the windows fully closed was reduced in the tinted car by a factor of 42 when compared with the erythemal UV measured in the untinted car. The ambient UVA irradiances at various locations within four different makes of car and a tractor were also measured with a broad band UVA hand-held meter. The average normalized daily UVA exposure (measured with a broad band UVA meter) was 1.3 times higher in a large family sedan when compared with that in a small hatchback and the UVA exposure in a car with tinted windows was 3.8 times less than in a similar untinted car.

  14. Comparative study of infrared techniques for fast biogeochemical sediment analyses

    NASA Astrophysics Data System (ADS)

    Hahn, A.; RoséN, P.; Kliem, P.; Ohlendorf, C.; Zolitschka, B.

    2011-10-01

    Analysis of sediment samples in the visible to mid infrared (IR) region requires small amounts of sample material and enables rapid and cost efficient geochemical analysis of mineral and organic sediment components. Here we use geochemical properties (total organic and inorganic carbon, biogenic silica, total nitrogen) from the ICDP deep drilling project PASADO to compare three different IR spectroscopy techniques: Diffuse Reflectance Fourier Transform IR Spectrometry (DRIFTS), Attenuated Total Reflectance Fourier Transform IR Spectroscopy (ATR-FTIRS) and Visible Near IR Spectroscopy (VNIRS). ATR-FTIRS and VNIRS are more rapid techniques compared to DRIFTS. Results show that calibration models developed using DRIFTS are most robust (correlation coefficient: R = 0.92 for TIC, R = 0.84 for BSi, R = 0.97 for TOC, R = 0.95 for TN). However, good statistical performance was also obtained by using ATR-FTIRS and VNIRS. When time and costs are limiting factors, these tools may be given preference for rapid biogeochemical screening.

  15. Comparative studies on uptake pathway of cadmium by Perna viridis

    NASA Astrophysics Data System (ADS)

    Fang, Zhanqiang

    2006-01-01

    Experiments were designed to expose the filter-feeding bivalve Perna viridis to different Cd-contaminated water environments in order to compare the different pathways through which Cd is accumulated. Results show that mussels can accumulate Cd through seawater, food, sediment and suspended particle pathways in a short period of time. Mussels' uptake of Cd through the seawater pathway reaches the highest concentration approximately 3 and 9 times larger than through the algae and sediment pathways respectively after 7 d. This indicates that the Cd-accumulation through seawater is most efficient. Results also indicate that the uptake directly through contaminated algae, particles or sediments ingested by mussels is less important when compared with the uptake of Cd by mussels through the seawater pathway. Metal uptake pathways and mechanisms of bioaccumulation by marine bivalve are also discussed in this paper.

  16. Clinical characteristics and outcomes of neonatal pertussis: a comparative study.

    PubMed

    Castagnini, Luis A; Munoz, Flor M

    2010-03-01

    We describe the features and outcomes of neonatal pertussis and compare these with neonates with non-pertussis acute respiratory illness from July 2000 through December 2007. Patients with pertussis had a more severe course of disease as evidenced by the clinical presentation, length of hospitalization, and oxygen requirement. Clinicians should have a high index of suspicion so that appropriate supportive care can be initiated promptly. PMID:20056236

  17. Comparative study of above ground biomass estimates for conterminous US

    NASA Astrophysics Data System (ADS)

    Neeti, N.; Kennedy, R. E.

    2013-12-01

    Accurate estimates of forest biomass are important for carbon accounting at both regional and national scale. There are four above ground biomass (AGB) maps available for conterminous US, one from the National Aeronautics and Space Administration (NASA), two from the United States Forest Service (USFS) (Blackard and Wilson) and one from the Woods Hole Research Center (WHRC). Although all four maps are meant to represent similar quantities, spatial patterns of AGB vary considerably from map to map. To use any of these AGB maps for carbon accounting, it is important to understand sources of uncertainty in individual maps and agreement and disagreement among them. Therefore, we compared the four AGB maps at ecoregion and state level to gain understanding of map consistency, leveraging discrepancies among maps to gain insight into the method and data sources. We also developed statewide summaries to compare with FIA forest AGB estimates, which are typically reported at the state level. We examined both absolute differences among these aggregated maps, and relative differences among regions within each map. The result shows that NASA biomass estimates are highest and Blackard estimates are lowest compared to other maps at both ecoregion and state level. The AGB for WHRC and Wilson are very similar at both ecoregion and state level specifically in the lower biomass regions compared to higher biomass regions. This could be associated with the differences in the spatial resolution of the data sources uses to generate these maps. At state level, WHRC map is found to be most similar and NASA biomass estimates least similar to FIA plot data. We discuss these differences in light of the different methods and data sources used to generate the maps.

  18. Comparative studies in direct slow-neutron capture calculations

    SciTech Connect

    Mughabghab, S.F.

    1987-08-01

    Primary E1 transitions due to thermal neutron capture by the nuclides /sup 9/Be, /sup 32,34/S, /sup 40,42,44,46,48/Ca, and /sup 58/Ni are quantitatively interpreted by the Lane-Lynn formula and are compared with recent optical model calculations. The two approaches are equivalent provided the internal region of the nucleus is excluded in the optical model approach. Theoretical justifications for such a procedure are briefly presented. 32 refs., 4 tabs.

  19. A comparative study of electric power distribution systems for spacecraft

    NASA Technical Reports Server (NTRS)

    Stuart, Thomas A.; King, Roger J.

    1990-01-01

    The electric power distribution systems for spacecraft are compared concentrating on two interrelated issues: the choice between dc and high frequency ac, and the converter/inverter topology to be used at the power source. The relative merits of dc and ac distribution are discussed. Specific converter and inverter topologies are identified and analyzed in detail for the purpose of detailed comparison. Finally, specific topologies are recommended for use in dc and ac systems.

  20. Comparative Study of Metadata Standards and Metadata Repositories

    NASA Astrophysics Data System (ADS)

    Pahuja, Gunjan

    2011-12-01

    Lot of work is being accomplished in the national and international standards communities to reach a consensus on standardizing metadata and repositories for organizing the metadata. Descriptions of several metadata standards and their importance to statistical agencies are provided in this paper. Existing repositories based on these standards help to promote interoperability between organizations, systems, and people. Repositories are vehicles for collecting, managing, comparing, reusing, and disseminating the designs, specifications, procedures, and outputs of systems, e.g. statistical surveys.

  1. [Comparative studies on fissure sealing: composite versus Cermet cement].

    PubMed

    Hickel, R; Voss, A

    1989-06-01

    Fifty two molars sealed with either composite or Cermet cement were compared. The composite sealant was applied after enamel etching using a rubber dam. Before sealing with Cermet cement the enamel was only cleaned with pumice powder and sodium hypochlorie and the material was applied without enamel etching. After an average follow-up of 1.6 years composite sealants proved to be significantly more reliable. Cermet cement sealings showed defects more frequently. PMID:2517111

  2. Histomorphometric and electron microscopic analyses of tibial epiphyseal plates from Cosmos 1887 rats

    NASA Technical Reports Server (NTRS)

    Duke, P. J.; Durnova, G.; Montufar-Solis, D.

    1990-01-01

    Previous studies have shown that the changes seen in the bones of growing rats exposed to microgravity are due in part to changes that occur in the growth plate during spaceflight. In this study, growth plates of rats flown aboard Cosmos 1887 (12.5-day flight plus 53.5-h recovery at 1 g) were analyzed using light and electron microscopy and computerized planimetry. The proliferative zone of flight animals was found to be significantly (P less than or equal to 0.01) larger than that of controls, while the reserve and hypertrophic/calcification zones were significantly reduced. Flight animals also had more cells per column in the proliferative zone than did controls and less in the hypertrophic/calcification region. The total number of cells, however, was significantly greater in flight animals. No difference was found in perimeter or in shape factor, but area was significantly less in flight animals. Electron microscopy showed that collagen fibrils in flight animals were wider than in controls. Since the time required for a cell to cycle through the growth plate is 2-3 days at 1 g, the results reported here represent both the effects of exposure to microgravity and the initial stages of recovery from that exposure.

  3. Trabecular bone histomorphometric measurements and contrast-to-noise ratio in CBCT

    PubMed Central

    Smedby, Ö; Brismar, T B; Moreno, R

    2014-01-01

    Objectives: The aim of this study was to evaluate how imaging parameters at clinical dental CBCT affect the accuracy in quantifying trabecular bone structures, contrast-to-noise ratio (CNR) and radiation dose. Methods: 15 radius samples were examined using CBCT (Accuitomo FPD; J. Morita Mfg., Kyoto, Japan). Nine imaging protocols were used, differing in current, voltage, rotation degree, voxel size, imaging area and rotation time. Radiation doses were measured using a kerma area product-meter. After segmentation, six bone structure parameters and CNRs were quantified. Micro-CT (μCT) images with an isotropic resolution of 20 μm were used as a gold standard. Results: Structure parameters obtained by CBCT were strongly correlated to those by μCT, with correlation coefficients >0.90 for all studied parameters. Bone volume and trabecular thickness were not affected by changes in imaging parameters. Increased tube current from 5 to 8 mA, decreased isotropic voxel size from 125 to 80 μm and decreased rotation angle from 360° to 180° affected correlations for trabecular termini negatively. Decreasing rotation degree also weakened correlations for trabecular separation and trabecular number at 80 μm voxel size. Changes in the rotation degree and tube current affected CNR significantly. The radiation dose varied between 269 and 1153 mGy cm2. Conclusions: Trabecular bone structure can be accurately quantified by clinical dental CBCT in vitro, and the obtained structure parameters are strongly related to those obtained by μCT. A fair CNR and strong correlations can be obtained with a low radiation dose, indicating the possibility for monitoring trabecular bone structure also in vivo. PMID:25168811

  4. New approaches to the study of comparative cognition.

    PubMed

    Kesner, R P

    1990-01-01

    The rat's memory capacity and performance render it an excellent model of human memory. Rats display serial position, serial anticipation learning, temporal coding, and repetition lag functions as well as utilization of retrospective and prospective codes that are nearly equivalent to that observed for humans. Furthermore, based on the above-mentioned memory performance functions, there are comparable memory-deficit patterns between brain-damaged rats and humans. Thus, the rat can serve as an excellent animal model to evaluate the efficacy of pharmacological treatments or brain damage upon memory. PMID:2247138

  5. Comparative study of WLS fibres for the ATLAS Tile Calorimeter

    NASA Astrophysics Data System (ADS)

    Gomes, A.; David, M.; Henriques, A.; Maio, A.

    1998-02-01

    The Wave Length Shifting (WLS) fibres are one of the most important components of the ATLAS barrel hadronic tile calorimeter (Tilecal). The fibres collect the hght produced in the injection molded scintillating tiles and transport it to the photomultipliers. Parameters like attenuation length and light yield are important, as well as flexibility and radiation hardness. Comparative results of WLS fibres produced by Bicron, Kuraray and Pol.Hi.Tech are presented. The performance of the fibres BCF91A from Bicron and S048 from Pol.Hi.Tech was significatively improved, but the most performant are still the double clad Y11 fibres from Kuraray.

  6. Comparative study of WLS fibres for the ATLAS tile calorimeter

    NASA Astrophysics Data System (ADS)

    Gomes, A.; David, M.; Henriques, A.; Maio, A.

    1997-02-01

    The Wave Length Shifting (WLS) fibres are one of the most important components of the ATLAS barrel hadronic tile calorimeter (Tilecal). The fibres collect the light produced in the injection molded scintillating tiles and transport it to the photomultipliers. Parameters like attenuation length and light yield are important, as well as flexibility and radiation hardness. Comparative results of WLS fibres produced by Bicron, Kuraray and Pol.Hi.Tech are presented. The performance of the fibres BCF91A from Bicron and S048 from Pol.Hi.Tech was significatively improved, but the most performant are still the double clad Y11 fibres from Kuraray.

  7. Inconsistencies between two attosecond pulse metrology methods: A comparative study

    SciTech Connect

    Kruse, J. E.; Skantzakis, E.; Charalambidis, D.; Tzallas, P.; Kalpouzos, C.; Tsakiris, G. D.

    2010-08-15

    The two basic approaches underlying most of the metrology of attosecond pulse trains are compared in the spectral region {approx}14-24 eV, that is, the second-order intensity volume autocorrelation and the resolution of attosecond beating by interference of two photon transitions (RABITT). They give rather dissimilar pulse durations. It is concluded that for the present experimental conditions RABITT may underestimate the duration under measurement, due to variations of the driving intensity, but in conjunction with theory allows an estimation of the relative contributions of two different electron trajectories to the extreme-ultraviolet (XUV) radiation.

  8. Comparative study of solar optics for paraboloidal concentrators

    NASA Technical Reports Server (NTRS)

    Wen, L.; Poon, P.; Carley, W.; Huang, L.

    1979-01-01

    Different analytical methods for computing the flux distribution on the focal plane of a paraboloidal solar concentrator are reviewed. An analytical solution in algebraic form is also derived for an idealized model. The effects resulting from using different assumptions in the definition of optical parameters used in these methodologies are compared and discussed in detail. These parameters include solar irradiance distribution (limb darkening and circumsolar), reflector surface specular spreading, surface slope error, and concentrator pointing inaccuracy. The type of computational method selected for use depends on the maturity of the design and the data available at the time the analysis is made.

  9. Histomorphometric Analysis of Cutaneous Remodeling in the Early Stage of the Scleroderma Model

    PubMed Central

    de Oliveira, Cristiane Carla; Velosa, Ana Paula Pereira; Parra, Edwin Roger; Capelozzi, Vera Luiza; Teodoro, Walcy Rosolia; Yoshinari, Natalino Hajime

    2009-01-01

    INTRODUCTION/OBJECTIVES Systemic sclerosis, or scleroderma, is a rheumatic disease characterized by autoimmunity, vasculopathy, and fibrosis of the skin and several internal organs. In the present study, our aim was to assess the skin alterations in animals with scleroderma during the first stages of disease induction. METHODS: To induce scleroderma, female New Zealand rabbits (n = 12) were subcutaneously immunized with 1 mg/ml of collagen V (Col V) in complete Freund’s adjuvant, twice with a thirty-day interval. Fifteen days later, the animals received an intramuscular booster with type V collagen in incomplete Freund’s adjuvant, twice with a fifteen-day interval. The control group was inoculated with 1 ml of 10 mM acetic acid solution diluted with an equal amount of Freund’s adjuvant. Serial dorsal skin biopsies were performed at 7, 15, and 30 days and stained with H&E, Masson’s trichrome and Picrosírius for morphological and morphometric analyses. RESULTS: Immunized rabbits presented a significant increase in collagen in skin collected seven days after the first immunization (p=0.05). CONCLUSION: The results from this experimental model may be very important to a better understanding of the pathogenic mechanisms involved in the beginning of human SSc. Therapeutic protocols to avoid early remodeling of the skin may lead to promising treatments for SSc in the future. PMID:19578663

  10. A histomorphometric meta-analysis of sinus elevation with various grafting materials

    PubMed Central

    Handschel, Jörg; Simonowska, Melani; Naujoks, Christian; Depprich, Rita A; Ommerborn, Michelle A; Meyer, Ulrich; Kübler, Norbert R

    2009-01-01

    Several grafting materials have been used in sinus augmentation procedures including autogenous bone, demineralized freeze-dried bone (DFDBA), hydroxyapatite, β-tricalcium phosphate (β-TCP), anorganic deproteinized bovine bone and combination of these and others. Up to now a subject of controversy in maxillofacial surgery and dentistry is, what is the most appropriate graft material for sinus floor augmentation. The aim of this study is to provide a body of evidence-based data regarding grafting materials in external sinus floor elevation concerning the fate of the augmented material at the histomorphological level, through a meta-analysis of the available literature. The literature searches were performed using the National Library of Medicine. The search covered all English and German literature from 1995 until 2006. For analyzing the amount of bone the parameter "Total Bone Volume" (TBV) was assessed. TBV is determined as the percentage of the section consisting of bone tissue. In a relatively early phase after implantation the autogenous bone shows the highest TBV values. Interestingly, the different TBV levels approximate during the time. After 9 months no statistically significant differences can be detected between the various grafting materials. From a clinical point of view, the use of autogenous bone is advantageous if a prosthetic rehabilitation (with functional loading) is expected within 9 months. In other cases the use of anorganic deproteinized bovine bone in combination with autogenous bone seems to be preferable. Donor side morbidity is ignored in this conclusion. PMID:19519903

  11. Effect of sex on histomorphometric properties of Langerhans islets in native chickens

    PubMed Central

    Parchami, Ali; Kusha, Sanaz

    2015-01-01

    The aim of the present study was to investigate the effect of gender on the distribution of pancreatic islets in native chicken. Ten adult male and ten adult female Isfahan native chickens were used in this experiment. Results showed a distinct sexual dimorphism in the native chicken pancreas which depends upon the various fractions of the pancreatic lobes, which were occupied by alpha, beta and mixed islets. In both sexes, the islets were more frequently found in the splenic and the third lobes, whereas they were more scarcely observed in the ventral and the dorsal lobes. In both sexes, there were no alpha islets in the dorsal and ventral pancreatic lobes. The mean percentage of beta islets in the third and splenic lobes were significantly greater in males than females (p < 0.05). However, the mean percentage of mixed islets in the third and splenic lobes were significantly greater in females than males (p < 0.05). The mean percentage of the alpha islets in the splenic and third lobes and the mean percentage of beta and mixed islets in the dorsal and ventral lobes was similar in both sexes in chickens. There was no sex difference in the mean percentage of whole gland islets (p > 0.05). PMID:26973769

  12. A comparative study of radiofrequency antennas for Helicon plasma sources

    NASA Astrophysics Data System (ADS)

    Melazzi, D.; Lancellotti, V.

    2015-04-01

    Since Helicon plasma sources can efficiently couple power and generate high-density plasma, they have received interest also as spacecraft propulsive devices, among other applications. In order to maximize the power deposited into the plasma, it is necessary to assess the performance of the radiofrequency (RF) antenna that drives the discharge, as typical plasma parameters (e.g. the density) are varied. For this reason, we have conducted a comparative analysis of three Helicon sources which feature different RF antennas, namely, the single-loop, the Nagoya type-III and the fractional helix. These antennas are compared in terms of input impedance and induced current density; in particular, the real part of the impedance constitutes a measure of the antenna ability to couple power into the plasma. The results presented in this work have been obtained through a full-wave approach which (being hinged on the numerical solution of a system of integral equations) allows computing the antenna current and impedance self-consistently. Our findings indicate that certain combinations of plasma parameters can indeed maximize the real part of the input impedance and, thus, the deposited power, and that one of the three antennas analyzed performs best for a given plasma. Furthermore, unlike other strategies which rely on approximate antenna models, our approach enables us to reveal that the antenna current density is not spatially uniform, and that a correlation exists between the plasma parameters and the spatial distribution of the current density.

  13. Comparative Study on Various Authentication Protocols in Wireless Sensor Networks.

    PubMed

    Rajeswari, S Raja; Seenivasagam, V

    2016-01-01

    Wireless sensor networks (WSNs) consist of lightweight devices with low cost, low power, and short-ranged wireless communication. The sensors can communicate with each other to form a network. In WSNs, broadcast transmission is widely used along with the maximum usage of wireless networks and their applications. Hence, it has become crucial to authenticate broadcast messages. Key management is also an active research topic in WSNs. Several key management schemes have been introduced, and their benefits are not recognized in a specific WSN application. Security services are vital for ensuring the integrity, authenticity, and confidentiality of the critical information. Therefore, the authentication mechanisms are required to support these security services and to be resilient to distinct attacks. Various authentication protocols such as key management protocols, lightweight authentication protocols, and broadcast authentication protocols are compared and analyzed for all secure transmission applications. The major goal of this survey is to compare and find out the appropriate protocol for further research. Moreover, the comparisons between various authentication techniques are also illustrated. PMID:26881272

  14. Beyond EUV lithography: a comparative study of efficient photoresists' performance

    PubMed Central

    Mojarad, Nassir; Gobrecht, Jens; Ekinci, Yasin

    2015-01-01

    Extreme ultraviolet (EUV) lithography at 13.5 nm is the main candidate for patterning integrated circuits and reaching sub-10-nm resolution within the next decade. Should photon-based lithography still be used for patterning smaller feature sizes, beyond EUV (BEUV) lithography at 6.x nm wavelength is an option that could potentially meet the rigid demands of the semiconductor industry. We demonstrate simultaneous characterization of the resolution, line-edge roughness, and sensitivity of distinct photoresists at BEUV and compare their properties when exposed to EUV under the same conditions. By using interference lithography at these wavelengths, we show the possibility for patterning beyond 22 nm resolution and characterize the impact of using higher energy photons on the line-edge roughness and exposure latitude. We observe high sensitivity of the photoresist performance on its chemical content and compare their overall performance using the Z-parameter criterion. Interestingly, inorganic photoresists have much better performance at BEUV, while organic chemically-amplified photoresists would need serious adaptations for being used at such wavelength. Our results have immediate implications for deeper understanding of the radiation chemistry of novel photoresists at the EUV and soft X-ray spectra. PMID:25783209

  15. Comparative Study on Various Authentication Protocols in Wireless Sensor Networks

    PubMed Central

    Rajeswari, S. Raja; Seenivasagam, V.

    2016-01-01

    Wireless sensor networks (WSNs) consist of lightweight devices with low cost, low power, and short-ranged wireless communication. The sensors can communicate with each other to form a network. In WSNs, broadcast transmission is widely used along with the maximum usage of wireless networks and their applications. Hence, it has become crucial to authenticate broadcast messages. Key management is also an active research topic in WSNs. Several key management schemes have been introduced, and their benefits are not recognized in a specific WSN application. Security services are vital for ensuring the integrity, authenticity, and confidentiality of the critical information. Therefore, the authentication mechanisms are required to support these security services and to be resilient to distinct attacks. Various authentication protocols such as key management protocols, lightweight authentication protocols, and broadcast authentication protocols are compared and analyzed for all secure transmission applications. The major goal of this survey is to compare and find out the appropriate protocol for further research. Moreover, the comparisons between various authentication techniques are also illustrated. PMID:26881272

  16. Strategy Maps in University Management: A Comparative Study

    ERIC Educational Resources Information Center

    Han, Shuangmiao; Zhong, Zhou

    2015-01-01

    In this study, the conceptual use of the strategy map approach and the strategy map which it produces have been adapted from the business sector and introduced as tools for achieving more effective strategic planning and management in higher education institutions (HEIs). This study discusses the development of strategy maps as transformational…

  17. Civic and Citizenship Education in 2009 (ICCS): A Comparative Study

    ERIC Educational Resources Information Center

    Schulz, Wolfram; Ainley, John

    2007-01-01

    The purpose of the "International Civic and Citizenship Education Study" (ICCS) is to investigate the ways in which young people are prepared to undertake their roles as citizens in a range of countries. The study will report on student achievement on a test of conceptual understandings and competencies in civic and citizenship education. It will…

  18. The Earmarks of College Success: A Causal-Comparative Study.

    ERIC Educational Resources Information Center

    Wisconsin Univ., Stevens Point. Office of Institutional Research.

    This study delineates characteristics related to suspended, probation, and nonprobation college students. The population of sub-population studies are composed of 1971-72 undergraduates at the University of Wisconsin-Stevens Point, and for some parts the entering freshmen for only 1971-72. By the end of the school year, all students were…

  19. Students' Perceptions of Online Learning: A Comparative Study

    ERIC Educational Resources Information Center

    Smart, Karl L.; Cappel, James J.

    2006-01-01

    In search of better, more cost effective ways to deliver instruction and training, universities and corporations have expanded their use of e-learning. Although several studies suggest that online education and blended instruction (a "blend" of online and traditional approaches) can be as effective as traditional classroom models, few studies have…

  20. "Mistakes Are a Fact of Life": A National Comparative Study

    ERIC Educational Resources Information Center

    Lunsford, Andrea A.; Lunsford, Karen J.

    2008-01-01

    This essay reports on a study of first-year student writing. Based on a stratified national sample, the study attempts to replicate research conducted twenty-two years ago and to chart the changes that have taken place in student writing since then. The findings suggest that papers are longer, employ different genres, and contain new error…

  1. Comparing International Curriculum Systems: The International Instructional Systems Study

    ERIC Educational Resources Information Center

    Creese, Brian; Gonzalez, Alvaro; Isaacs, Tina

    2016-01-01

    This paper sets out the main findings of the International Instructional Systems Study (IISS), conducted by the UCL Institute of Education and funded by the Center on International Education Benchmarking (CIEB). The study examined the instructional systems and intended curricula of six "high performing" countries and two US states. The…

  2. Tribal College and University Accreditation: A Comparative Study.

    ERIC Educational Resources Information Center

    Putman, T. Elizabeth Mennell

    In the context of tribal colleges, accreditation is a complex issue. This study, which is a replication of a study by J. McDonald in 1982, is an examination of how the perceptions of tribal college faculty, staff, and governing board members toward the importance and impact of accreditation have changed since 1982. Surveys were administered to the…

  3. Asperger Syndrome and Schizophrenia: A Comparative Neuropsychological Study

    ERIC Educational Resources Information Center

    Marinopoulou, Maria; Lugnegård, Tove; Unenge Hallerbäck, Maria; Gillberg, Christopher; Billstedt, Eva

    2016-01-01

    There has been an increasing interest in possible connections between autism spectrum disorder (ASD) and schizophrenia in the last decade. Neuropsychological comparison studies have, however, been few. The present study examined similarities and differences in intellectual and executive functioning between adults with Asperger syndrome (AS) and…

  4. Metafunctional Practices in Medical Research Articles: A Comparative Study

    ERIC Educational Resources Information Center

    Assadi, Nader; Ghassemi, Mojtaba; Madadi, Alireza

    2014-01-01

    The purpose of this study is to explore any possible difference among the verb types chosen in articles written in English by the non-natives and natives. In so doing, Halliday's Systemic Functional Grammar (1994) was employed. 80 published articles from the medical sciences field of study were chosen from among which 40 were written by native…

  5. Nonceramic hydroxyapatite bone derivative in sinus augmentation procedures: clinical and histomorphometric observations in 10 consecutive cases.

    PubMed

    Artzi, Zvi; Nemcovsky, Carlos E; Dayan, Dan

    2003-08-01

    A synthetic, nonceramic resorbable hydroxyapatite (R-HA) was applied to augment the subantral area in 10 consecutive sinus lift procedures in humans. Implants were simultaneously placed in eight patients; in the remaining two, where residual bone height was less than 3 mm, a two-stage surgical approach was carried out. The aim of the study was to examine, clinically and histopathologically at 12 months, the healing pattern of these augmented sinuses around the implants. In the simultaneous technique, radiopaque grafted mineral surrounded the implants. In the two-stage technique, R-HA particles filled the augmented site and were confined to the subantral area. At the uncovering phase, all implants (n = 36) were stable, with no clinical bone resorption around the cervix. A 2.5-mm trephine bur was used to collect specimens from the 10 augmented sites at the lateral-deep area. Histologically, new bone formation was evident in all examined cores. R-HA particles were primarily surrounded by newly formed bone, mostly woven bone, in different stages of remodeling. However, in the deep areas of the specimen cores, lamellar bone fragments were also seen. Morphometric measurements showed that the mean bone area of the 10 sites was 28.1% at the lateral/external side and 37.8% at the deep/inward side. Under polarizing microscopy, the mean lamellar:woven bone ratio was 1:7.2 at the lateral side and 1:4.2 at the deep end. Differences were statistically significant. R-HA proved to be a suitable filler material for osseointegrated implants in sinus augmentation procedures, since it showed both biocompatible and osteoconductive properties. PMID:12956482

  6. Study on Lexical Cohesion in English and Persian Research Articles (A Comparative Study)

    ERIC Educational Resources Information Center

    Mirzapour, Fatemeh; Ahmadi, Maryam

    2011-01-01

    The present study aims to analyze comparatively English and Persian research articles (Linguistics, Literature, and Library and Information disciplines) in terms of number and degree of utilization of sub-types of lexical cohesion in order to appreciate textualization processes in the two languages concerned. The study analyzes 60 research…

  7. A critique of comparative studies of brain size

    PubMed Central

    Healy, Susan D; Rowe, Candy

    2006-01-01

    In recent years, there have been over 50 comparative analyses carried out in which social or ecological variables have been used to explain variation in whole brain size, or a part thereof, in a range of vertebrate species. Here, we review this body of work, pointing out that there are a number of substantial problems with some of the assumptions that underpin the hypotheses (e.g. what brain size means), with the data collection and with the ways in which the data are combined in the analyses. These problems are particularly apparent in those analyses in which attempts are made to correlate complex behaviour with parts of the brain that carry out multiple functions. We conclude that now is the time to substantiate these results with data from experimental manipulations. PMID:17476764

  8. Leptin in Teleost Fishes: An Argument for Comparative Study

    PubMed Central

    Copeland, Donald L.; Duff, Robert Joel; Liu, Qin; Prokop, Jeremy; Londraville, Richard Lyle

    2011-01-01

    All organisms face tradeoffs with regard to how limited energy resources should be invested. When is it most favorable to grow, to reproduce, how much lipid should be allocated to storage in preparation for a period of limited resources (e.g., winter), instead of being used for growth or maturation? These are a few of the high consequence fitness “decisions” that represent the balance between energy acquisition and allocation. Indeed, for animals to make favorable decisions about when to grow, eat, or reproduce, they must integrate signals among the systems responsible for energy acquisition, storage, and demand. We make the argument that leptin signaling is a likely candidate for an integrating system. Great progress has been made understanding the leptin system in mammals, however our understanding in fishes has been hampered by difficulty in cloning fish orthologs of mammalian proteins and (we assert), underutilization of the comparative approach. PMID:21716655

  9. Comparative Study of the Thermal Conductivity of Solid Biomass Fuels

    PubMed Central

    2016-01-01

    The thermal conductivity of solid biomass fuels is useful information in the investigation of biomass combustion behavior and the development of modeling especially in the context of large scale power generation. There are little published data on the thermal conductivity of certain types of biomass such as wheat straw, miscanthus, and torrefied woods. Much published data on wood is in the context of bulk materials. A method for determining the thermal conductivities of small particles of biomass fuels has been developed using a custom built test apparatus. Fourteen different samples of various solid biomass fuel were processed to form a homogenized pellet for analysis. The thermal conductivities of the pelletized materials were determined and compared against each other and to existing data. PMID:27041819

  10. [Comparative study of immunomodulating properties of phenibut and gammoxin].

    PubMed

    Tiurenkov, I N; Samotrueva, M A; Kuleshevskaia, N R; Berestovitskaia, V M; Vasil'eva, O S

    2010-12-01

    Experiments on CBA mice with model immunodepression induced by cyclophosphamide showed that phenibut (25 mg/kg) and gammoxin (25 mg/kg) recover both cellular and humoral immunoreactivity and restore lymphoproliferative processes in immunocompetent organs, which is evidence for pronounced immunocorrecting properties of these drugs. A comparative analysis of the immunomodulating activity of phenibut and gammoxin showed that the latter drug predominantly affects the process of immunocompetent cell maturation (growth in mass and cellularity of thymus and spleen--the central immunocompetent organs), while phenibut mostly influences the realization of the final reaction of the primary anti-erythrocyte immune response (significant correction of local infiltration delayed-type hypersensitivity reaction and antibody formation). This difference can be related to the fact that the drugs influence GABA receptors of different types, whereby gammoxin acts on these receptors in immunocompetent organs and phenibut acts on the receptors in lymphocytes. PMID:21395013

  11. A comparative study of SAR data compression schemes

    NASA Technical Reports Server (NTRS)

    Lambert-Nebout, C.; Besson, O.; Massonnet, D.; Rogron, B.

    1994-01-01

    The amount of data collected from spaceborne remote sensing has substantially increased in the last years. During same time period, the ability to store or transmit data has not increased as quickly. At this time, there is a growing interest in developing compression schemes that could provide both higher compression ratios and lower encoding/decoding errors. In the case of the spaceborne Synthetic Aperture Radar (SAR) earth observation system developed by the French Space Agency (CNES), the volume of data to be processed will exceed both the on-board storage capacities and the telecommunication link. The objective of this paper is twofold: to present various compression schemes adapted to SAR data; and to define a set of evaluation criteria and compare the algorithms on SAR data. In this paper, we review two classical methods of SAR data compression and propose novel approaches based on Fourier Transforms and spectrum coding.

  12. A comparative study of computational methods in cosmic gas dynamics

    NASA Technical Reports Server (NTRS)

    Van Albada, G. D.; Van Leer, B.; Roberts, W. W., Jr.

    1982-01-01

    Many theoretical investigations of fluid flows in astrophysics require extensive numerical calculations. The selection of an appropriate computational method is, therefore, important for the astronomer who has to solve an astrophysical flow problem. The present investigation has the objective to provide an informational basis for such a selection by comparing a variety of numerical methods with the aid of a test problem. The test problem involves a simple, one-dimensional model of the gas flow in a spiral galaxy. The numerical methods considered include the beam scheme, Godunov's method (G), the second-order flux-splitting method (FS2), MacCormack's method, and the flux corrected transport methods of Boris and Book (1973). It is found that the best second-order method (FS2) outperforms the best first-order method (G) by a huge margin.

  13. Assessing Holland Types on the Internet: A Comparative Study

    ERIC Educational Resources Information Center

    Miller, Mark J.; Cowger, Ernest, Jr.; Young, Tony; Tobacyk, Jerome; Sheets, Tillman; Loftus, Christina

    2008-01-01

    This study examined the degree of similarity between scores on the Self-Directed Search and an online instrument measuring Holland types. A relatively high congruency score was found between the two measures. Implications for career counselors are discussed.

  14. Neuropathology of HIV infection in haemophiliacs: comparative necropsy study.

    PubMed Central

    Esiri, M. M.; Scaravilli, F.; Millard, P. R.; Harcourt-Webster, J. N.

    1989-01-01

    OBJECTIVE--To discover whether pathological and neuropathological findings at necropsy are different in haemophiliacs and other subjects positive for HIV. DESIGN--Pathological and neuropathological findings at necropsy were compared in haemophiliacs and non-haemophiliacs, most of them homosexual men. SETTING--Necropsies performed in the south of England. SUBJECTS--11 Haemophiliacs (mean age 41, range 15-69) and 31 non-haemophiliacs, 29 of whom were homosexual men (mean age 40, range 21-60). AIDS was diagnosed before death in four haemophiliacs and all but one of the non-haemophiliacs. MAIN OUTCOME MEASURES--Prevalence of various forms of neuropathology and systemic pathology in the haemophiliacs and non-haemophiliacs, compared with Fisher's exact test. RESULTS--The prevalences of opportunistic infections of the central nervous system were significantly higher in the non-haemophiliacs (cerebral toxoplasmosis 23% (7), progressive multifocal leucoencephalopathy 10% (3), and cerebral cytomegalovirus infection 19% (6) in the non-haemophiliacs v no cases in the haemophiliacs). The prevalences of fresh and old intracranial haemorrhages and cirrhosis of the liver were significantly higher in the haemophiliacs (fresh intracranial haemorrhage 45% (5), old intracranial haemorrhage 36% (4), and cirrhosis of the liver 27% (3) in the haemophiliacs v no cases in the non-haemophiliacs). The prevalence of neuropathological changes in the non-haemophiliacs was similar to that found in other necropsy series. CONCLUSIONS--The main causes of death in haemophiliacs positive for HIV included intracranial haemorrhage and cirrhosis of the liver. The haemophiliacs died when the characteristic neuropathological changes associated with HIV infection were at a fairly early stage in their development. PMID:2513933

  15. Comparative study of ion conducting pathways in borate glasses

    SciTech Connect

    Hall, Andreas; Swenson, Jan; Adams, Stefan

    2006-11-01

    The conduction pathways in metal-halide doped silver, lithium, and sodium diborate glasses have been examined by bond valence analysis of reverse Monte Carlo (RMC) produced structural models of the glasses. Although all glass compositions have basically the same short-range structure of the boron-oxygen network, it is evident that the intermediate-range structure is strongly dependent on the type of mobile ion. The topography of the pathways and the coordination of the pathway sites differ distinctly between the three glass systems. The mobile silver ions in the AgI-doped glass tend to be mainly iodine-coordinated and travel in homogeneously distributed pathways located in salt-rich channels of the borate network. In the NaCl-doped glass, there is an inhomogeneous spatial distribution of pathways that reflects the inhomogeneous introduction of salt ions into the glass. However, since the salt clusters are not connected, no long-range conduction pathways are formed without including also oxygen-rich regions. The pathways in the LiCl-doped glass are slightly more evenly distributed compared to the NaCl-doped glass (but not as ordered as in the AgI-doped glass), and the regions of mainly oxygen-coordinated pathway sites are of higher importance for the long-range migration. In order to more accurately investigate how these differences in the intermediate-range order of the glasses affect the ionic conductivity, we have compared the realistic structure models to more or less randomized structures. An important conclusion from this comparison is that we find no evidence that a pronounced intermediate-range order in the atomic structure or in the network of conduction pathways, as in the AgI-doped glass, is beneficial for the dc conductivity.

  16. Priority Questions and Horizon Scanning for Conservation: A Comparative Study

    PubMed Central

    Kark, Salit; Sutherland, William J.; Shanas, Uri; Klass, Keren; Achisar, Hila; Dayan, Tamar; Gavrieli, Yael; Justo-Hanani, Ronit; Mandelik, Yael; Orion, Nir; Pargament, David; Portman, Michelle; Reisman-Berman, Orna; Safriel, Uriel N.; Schaffer, Gad; Steiner, Noa; Tauber, Israel; Levin, Noam

    2016-01-01

    Several projects aimed at identifying priority issues for conservation with high relevance to policy have recently been completed in several countries. Two major types of projects have been undertaken, aimed at identifying (i) policy-relevant questions most imperative to conservation and (ii) horizon scanning topics, defined as emerging issues that are expected to have substantial implications for biodiversity conservation and policy in the future. Here, we provide the first overview of the outcomes of biodiversity and conservation-oriented projects recently completed around the world using this framework. We also include the results of the first questions and horizon scanning project completed for a Mediterranean country. Overall, the outcomes of the different projects undertaken (at the global scale, in the UK, US, Canada, Switzerland and in Israel) were strongly correlated in terms of the proportion of questions and/or horizon scanning topics selected when comparing different topic areas. However, some major differences were found across regions. There was large variation among regions in the percentage of proactive (i.e. action and response oriented) versus descriptive (non-response oriented) priority questions and in the emphasis given to socio-political issues. Substantial differences were also found when comparing outcomes of priority questions versus horizon scanning projects undertaken for the same region. For example, issues related to climate change, human demography and marine ecosystems received higher priority as horizon scanning topics, while ecosystem services were more emphasized as current priority questions. We suggest that future initiatives aimed at identifying priority conservation questions and horizon scanning topics should allow simultaneous identification of both current and future priority issues, as presented here for the first time. We propose that further emphasis on social-political issues should be explicitly integrated into future

  17. Priority Questions and Horizon Scanning for Conservation: A Comparative Study.

    PubMed

    Kark, Salit; Sutherland, William J; Shanas, Uri; Klass, Keren; Achisar, Hila; Dayan, Tamar; Gavrieli, Yael; Justo-Hanani, Ronit; Mandelik, Yael; Orion, Nir; Pargament, David; Portman, Michelle; Reisman-Berman, Orna; Safriel, Uriel N; Schaffer, Gad; Steiner, Noa; Tauber, Israel; Levin, Noam

    2016-01-01

    Several projects aimed at identifying priority issues for conservation with high relevance to policy have recently been completed in several countries. Two major types of projects have been undertaken, aimed at identifying (i) policy-relevant questions most imperative to conservation and (ii) horizon scanning topics, defined as emerging issues that are expected to have substantial implications for biodiversity conservation and policy in the future. Here, we provide the first overview of the outcomes of biodiversity and conservation-oriented projects recently completed around the world using this framework. We also include the results of the first questions and horizon scanning project completed for a Mediterranean country. Overall, the outcomes of the different projects undertaken (at the global scale, in the UK, US, Canada, Switzerland and in Israel) were strongly correlated in terms of the proportion of questions and/or horizon scanning topics selected when comparing different topic areas. However, some major differences were found across regions. There was large variation among regions in the percentage of proactive (i.e. action and response oriented) versus descriptive (non-response oriented) priority questions and in the emphasis given to socio-political issues. Substantial differences were also found when comparing outcomes of priority questions versus horizon scanning projects undertaken for the same region. For example, issues related to climate change, human demography and marine ecosystems received higher priority as horizon scanning topics, while ecosystem services were more emphasized as current priority questions. We suggest that future initiatives aimed at identifying priority conservation questions and horizon scanning topics should allow simultaneous identification of both current and future priority issues, as presented here for the first time. We propose that further emphasis on social-political issues should be explicitly integrated into future

  18. ICMSF methods studies. VIII. Comparative study for the enumeration of Clostridium perfringens in foods.

    PubMed

    Hauschild, A H; Gilbert, R J; Harmon, S M; O'Keeffe, M F; Vahlefeld, R

    1977-07-01

    Four methods were compared in an international comparative study for the enumeration of Clostridium perfringens: the SFP (Shahidi-Ferguson perfringens) agar (A), TSC (tryptose-sulfite-cycloserin) agar (B), SC (sulfite-cycloserine) agar (C), and neomycin blood agar (D) methods. The confirmed C. perfringens counts were slightly lower for D than for A-C. The percentages of presumptive colonies confirmed as C. perfringens were essentially the same in each method. The relative numbers of nonspecific colonies were the lowest in C, followed by B, D, and A. The methods were also compared for simplicity and for aspects associated with the recognition and selection of presumptive colonies. PMID:195698

  19. A Comparative Study of Aerocapture Missions with a Mars Destination

    NASA Technical Reports Server (NTRS)

    Vaughan, Diane; Miller, Heather C.; Griffin, Brand; James, Bonnie F.; Munk, Michelle M.

    2005-01-01

    Conventional interplanetary spacecraft use propulsive systems to decelerate into orbit. Aerocapture is an alternative approach for orbit capture, in which the spacecraft makes a single pass through a target destination's atmosphere. Although this technique has never been performed, studies show there are substantial benefits of using aerocapture for reduction of propellant mass, spacecraft size, and mission cost. The In-Space Propulsion (ISP) Program, part of NASA's Science Mission Directorate, has invested in aerocapture technology development since 2002. Aerocapture investments within ISP are largely driven by mission systems analysis studies, The purpose of this NASA-funded report is to identify and document the fundamental parameters of aerocapture within previous human and robotic Mars mission studies which will assist the community in identifying technology research gaps in human and robotic missions, and provide insight for future technology investments. Upon examination of the final data set, some key attributes within the aerocapture disciplines are identified.

  20. Autonomic predictors of recovery following surgery: A comparative study

    PubMed Central

    Williamson, John B.; Lewis, Greg; Grippo, Angela J.; Lamb, Damon; Harden, Emily; Handleman, Mika; Lebow, Jocelyn; Carter, C. Sue; Porges, Stephen W.

    2015-01-01

    Although heart rate and temperature are continuously monitored in patients during recovery following surgery, measures that extract direct manifestations of neural regulation of autonomic circuits from the beat-to-beat heart rate may be more sensitive to outcome. We explore the relationship between features of autonomic regulation and survival in the prairie vole, a small mammal, with features of vagal regulation of the heart similar to humans. Cardiac vagal regulation is manifested in the beat-to-beat heart rate variability (HRV) pattern and can be quantified by extracting measures of the amplitude of periodic oscillations associated with spontaneous breathing. Thus, monitoring beat-to-beat heart rate patterns post-surgery in the prairie vole may provide an opportunity to dynamically assess autonomic adjustments during recovery. Surgeries to implant telemetry devices to monitor body temperature and continuous ECG in prairie voles are routinely performed in our laboratory. Ten of these implanted prairie voles died within 48 h post-surgery. To compare the post-surgery autonomic trajectories with typical surviving prairie voles, the post-surgery data from 17 surviving prairie voles were randomly selected. The data are reported hourly for 27 prairie voles between 6 and 14 h (1 h before the demise of the first subject) post-surgery. Receiver operator curves were calculated hourly for each variable to evaluate sensitivity in discriminating survival. The data illustrate that measures of HRV are the most sensitive indicators. These findings provide a foundation for investigating further neural mechanisms of cardiovascular function. PMID:20451468

  1. Comparative study of different isolates of murine sarcoma virus.

    PubMed Central

    Donoghue, D J; Sharp, P A; Weinberg, R A

    1979-01-01

    The RNA genomes of a variety of murine sarcoma viruses (MSV) were compared by heteroduplex analysis. These viruses included the Moloney-derived isolates 124-MSV, m1-MSV, m3-MSV, HT1-MSV, and NP-MSV and also two independent isolates, Gazdar MSV and 1712-MSV. All of these viral genomes exhibited the acquired cellular sequences previously identified in 3124-MSV and thought to be responsible for transformation and sarcomagenesis. The location of the acquired cellular sequences within the envelope gene was variable in different MSV isolates, suggesting that the cellular sequences can be expressed in different positions relative to murine leukemia virus-derived information present in MSV. Deletions in the gag coding region of the different MSVs were consistent with their known gag-related gene products. Based on several features of the hetero-duplex analysis and the known genealogical relationships of the different MSVs, various possible mechanisms for the formation of MSV are considered. Images PMID:229256

  2. Learning from imbalanced data: a comparative study for colon CAD

    NASA Astrophysics Data System (ADS)

    Yang, Xiaoyun; Zheng, Yalin; Siddique, Musib; Beddoe, Gareth

    2008-03-01

    Classification plays an important role in the reduction of false positives in many computer aided detection and diagnosis methods. The difficulty of classifying polyps lies in the variation of possible polyp shapes and sizes and the imbalance between the number of polyp and non-polyp regions available in the training data. CAD schemes for medical applications demand high levels of sensitivity even at the expense of keeping a certain number of false positives. In this paper, we investigate some state-of-the-art solutions to the imbalanced data problem: Synthetic Minority Over-sampling Technique (SMOTE) and weighted Support Vector Machines (SVM). We tested these methods using a diverse database of CT colonography, which included a wide spectrum of dificult cases to detect polyps. We performed several experiments with different combinations of over-sampling techniques on training data. The results demonstrated that SVMs have achieved much better performance over C4.5 with different over-sampling techniques. Also, the results show that weighted SVM without over-sampling can achieve comparable performance in terms of sensitivity and specificity to conventional SVM combined with the over-sampling approach.

  3. Muscle wasting in chronic alcoholics: comparative histochemical and biochemical studies.

    PubMed Central

    Langohr, H D; Wiethölter, H; Peiffer, J

    1983-01-01

    The comparative electrophysiologic, histochemical, and biochemical investigation of the anterior tibial muscle of 13 alcoholics indicates that neuropathy could be the cause of the chronic muscle weakness and wasting. Myopathic alterations did not predominate in the findings. It was concluded that the proximal muscle atrophy could also be attributed to neurogenic damage. Histochemical reactions in muscle specimens showed a selective type 2 atrophy and a slight increase of the mean diameter of type 1 fibres. Biochemical investigations revealed that the activities of a number of enzymes representative of energy supplying pathways--the glycogenolysis and glycolysis--as well as acid phosphatase activity in the muscle were lowered. A relationship could be assumed between the lowered glycolytic activity and the decline of the mean diameter of type 2 fibres. Oxidative enzymes were of similar activity in the alcoholics and the control group. The glycolytic enzyme activities were particularly important, being the most sensitive indicators of the onset, intensity, and course of neurogenic damage. These activities probably normalise during reinnervation of a muscle earlier than do the morphologic alterations; however, they were markedly lower in alcoholics with impaired liver function and cachexia, probably because of the catabolic metabolic conditions present in these cases. Images PMID:6221080

  4. Verruciform xanthoma: report of three patients with comparative dermoscopic study.

    PubMed

    Ohnishi, T; Shiraishi, H; Fukaya, S; Tanaka, T; Watanabe, S

    2015-03-01

    We report three cases of verruciform xanthoma (VX) in male patients aged 82, 88 and 39 years, respectively. The clinical appearance was of a mulberry-like area consisting of small papillae, which is typical of and specific to VX, and the diagnosis were histologically confirmed in all cases. Dermoscopy revealed that each surface papilla contained linear or hairpin vessels, which were surrounded by a marginal whitish rim. These structures are thought to correspond to dilated vessels in dermal papillae and papillated acanthotic epidermis, respectively. Furthermore, observation under compression (similar to diascopy) revealed yellow dots and debris, reflecting lipid-laden foam cells. In order to compare these findings with those of other disorders with similar findings, two patients with xanthogranuloma, six with sebaceous naevus, and three with senile sebaceous hyperplasia were examined. The dermoscopic findings in these patients were not similar to those of VX. Therefore, we believe that the above dermoscopic findings are specific to VX and could be helpful in diagnosis. PMID:25476138

  5. Comparative study of medium damped and detuned linear accelerator structures

    SciTech Connect

    Jean-Francois Ostiguy et al.

    2001-08-22

    Long range wakefields are a serious concern for a future linear collider based on room temperature accelerating structures. They can be suppressed either by detuning and or local damping or with some combination of both strategies. Detuning relies on precisely phasing the contributions of the dipole modes excited by the passage of a single bunch. This is accomplished by controlling individual mode frequencies, a process which dictates individual cell dimensional tolerances. Each mode must be excited with the correct strength; this in turn, determines cell-to-cell alignment tolerances. In contrast, in a locally damped structure, the modes are attenuated at the cell level. Clearly, mode frequencies and relative excitation become less critical in that context; mechanical fabrication tolerances can be relaxed. While local damping is ideal from the stand-point of long range wakefield suppression, this comes at the cost of reducing the shunt impedance and possibly unacceptable localized heating. Recently, the Medium Damped Structure (MDS), a compromise between detuning and local damping, has generated some interest. In this paper, we compare a hypothetical MDS to the NLC Rounded Damped Detuned Structure (RDDS) and investigate possible advantages from the standpoint fabrication tolerances and their relation to beam stability and emittance preservation.

  6. A comparative structural study of wet and dried ettringite

    SciTech Connect

    Renaudin, G.; Filinchuk, Y.; Neubauer, J.; Goetz-Neunhoeffer, F.

    2010-03-15

    Two different techniques were used to compare structural characteristics of 'wet' ettringite (stored in the synthesis mother liquid) and 'dried' ettringite (dried to 35% relative humidity over saturated CaCl{sub 2} solution). Lattice parameters and the water content in the channel region of the structure (site occupancy factor of the water molecule not bonded to cations) as well as microstructure parameters (size and strain) were determined from a Rietveld refinement on synchrotron powder diffraction data. Local environment of sulphate anions and of the hydrogen bonding network was characterized by Raman spectroscopy. Both techniques led to the same conclusion: the 'wet' ettringite sample immersed in the mother solution from the synthesis presents similar structural features as ettringite dried to 35% relative humidity. An increase of the a lattice parameter combined with a decrease of the c lattice parameter occurs on drying. The amount of structural water, the point symmetry of sulphate and the hydrogen bond network are unchanged when passing from the wet to the dried ettringite powder. Ettringite does not form a high-hydrate polymorph in equilibrium with alkaline solution, in contrast to the AFm phases that lose water molecules on drying. According to these results we conclude that ettringite precipitated in aqueous solution at the early hydration stages is of the same chemical composition as ettringite present in the hardening concrete.

  7. A comparative study of measurements from radiosondes, rocketsondes, and satellites

    NASA Technical Reports Server (NTRS)

    Nestler, M. S.

    1983-01-01

    Direct comparisons of operational products derived from measurements of radiance by satellites to measurements from conventional in situ sensors are important for the evaluation of satellite systems. However, errors in the in situ measurements themselves complicate such comparisons. Atmospheric temporal and spatial variability are also influential. These issues are investigated by means of a special field program composed of flights of dual radiosondes and multiple radiosondes launched near the time of NOAA-6 overpasses. Satellite derived mean layer temperatures, geopotential heights, and winds are compared with the same quantities determined from the in situ sensors. Of particular interest is the impact of in situ errors on these comparisons. It is shown that the radiosonde provides a precise pressure height relationship and therefore precise data for synoptic type use. Radar tracking of the radiosondes reveals, however, an imprecise pressure measurement which causes large differences between the actual altitude of the radiosonde and the altitude at which it is calculated to be. Radiosondes should be radar tracked and pressures calculated if the data are to be used for purposes other than synoptic use. Evaluation of rocketsonde data reveals a temperature precision of 1 to 2 K below about 55 km. Above 55 km, the precision decreases rapidly; rms differences of up to 11 K are obtained.

  8. A Comparative Study of Some Dynamic Stall Models

    NASA Technical Reports Server (NTRS)

    Reddy, T. S. R.; Kaza, K. R. V.

    1987-01-01

    Three semi-empirical aerodynamic stall models are compared with respect to their lift and moment hysteresis loop prediction, limit cycle behavior, easy implementation, and feasibility in developing the parameters required for stall flutter prediction of advanced turbines. For the comparison of aeroelastic response prediction including stall, a typical section model and a plate structural model are considered. The response analysis includes both plunging and pitching motions of the blades. In model A, a correction to the angle of attack is applied when the angle of attack exceeds the static stall angle. In model B, a synthesis procedure is used for angles of attack above static stall angles and the time history effects are accounted through the Wagner function. In both models the life and moment coefficients for angle of attack below stall are obtained from tabular data for a given Mach number and angle of attack. In model C, referred to an the ONERA model, the life and moment coefficients are given in the form of two differential equations, one for angles below stall, and the other for angles above stall. The parameters of those equations are nonlinear functions of the angle of attack.

  9. [Comparative study of 2 methods of measuring intestinal transit time].

    PubMed

    Vidal-Neira, L; León-Barúa, R

    1981-01-01

    In 20 healthy volunteers, intestinal transit times, obtained following a simple method, recently described, in which a small liquid-containing rubber bag is used as a marker, were compared with the times obtained following, simultaneously, another method, already universally accepted, in which small barium-impregnated pellets are used as markers. The intestinal transit determined with the rubber bag (TTI-B) (14.1 - 79.2 hours; mean +/- s.d.: 42.4 +/- 20.7 hours) were significantly shorter than the times determined with the plastic pellets (TTI) (26.4 - 88.1 hours; mean +/- s.d.: 60.2 +/- 25.5 hours (P less than 0.001). But, TTI-B and TTI correlate closely (r: + 0.86), and, furthermore, TTI-B results may be converted to TTI results with the help of a simple regression equation: TTI (in minutes) = 831 + 1.09 TTI-B (in minutes). After analyzing what has been observed in the present work and in previous works, it was concluded that the new method to measure intestinal transient time using the small rubber bag is reliable and simple, and that it may help to better understand what happens in some important gastrointestinal problems. PMID:7342626

  10. A Comparative Study Using CFD to Predict Iced Airfoil Aerodynamics

    NASA Technical Reports Server (NTRS)

    Chi, x.; Li, Y.; Chen, H.; Addy, H. E.; Choo, Y. K.; Shih, T. I-P.

    2005-01-01

    WIND, Fluent, and PowerFLOW were used to predict the lift, drag, and moment coefficients of a business-jet airfoil with a rime ice (rough and jagged, but no protruding horns) and with a glaze ice (rough and jagged end has two or more protruding horns) for angles of attack from zero to and after stall. The performance of the following turbulence models were examined by comparing predictions with available experimental data. Spalart-Allmaras (S-A), RNG k-epsilon, shear-stress transport, v(sup 2)-f, and a differential Reynolds stress model with and without non-equilibrium wall functions. For steady RANS simulations, WIND and FLUENT were found to give nearly identical results if the grid about the iced airfoil, the turbulence model, and the order of accuracy of the numerical schemes used are the same. The use of wall functions was found to be acceptable for the rime ice configuration and the flow conditions examined. For rime ice, the S-A model was found to predict accurately until near the stall angle. For glaze ice, the CFD predictions were much less satisfactory for all turbulence models and codes investigated because of the large separated region produced by the horns. For unsteady RANS, WIND and FLUENT did not provide better results. PowerFLOW, based on the Lattice Boltzmann method, gave excellent results for the lift coefficient at and near stall for the rime ice, where the flow is inherently unsteady.

  11. Governance Paradigms of Public Universities: An International Comparative Study

    ERIC Educational Resources Information Center

    Christopher, Joe

    2012-01-01

    This study aims to develop a conceptual model of the wider influencing forces impacting the governance paradigms of public universities. It draws on the multi-theoretical governance concept and seeks to identify these forces through the lens of chief audit executives using a qualitative research approach. The interview data supported by published…

  12. Workplace Discrimination and Americans with Psychiatric Disabilities: A Comparative Study

    ERIC Educational Resources Information Center

    An, Sunghee; Roessler, Richard T.; McMahon, Brian T.

    2011-01-01

    This study reports findings from an analysis of employment allegations and resolutions maintained in the U.S. Equal Employment Opportunity Commission (EEOC) database. Spanning the years 1992 to 2005, the data were aggregated for individuals with psychiatric disabilities and individuals with a variety of physical, sensory, and neurological…

  13. Factors Influencing International Students' Career Choice: A Comparative Study

    ERIC Educational Resources Information Center

    Singaravelu, Hemla D.; White, Lyle J.; Bringaze, Tammy B.

    2005-01-01

    This study examines the career development behavior of Asian international, non-Asian international, and domestic students, specifically the certainty of career and major choice and environmental factors that have influenced their choices. Environmental factors include family, school counselors, teacher, friends, and government. The results show…

  14. Pre- and Post KERA Students' Writing Skills: A Comparative Study.

    ERIC Educational Resources Information Center

    Sultana, Qaisar; Kay, Lisa

    This study was conducted to determine whether the writing skills, as measured by the University Writing Requirement (UWR), of Kentucky high school graduates who had participated in Kentucky's Commonwealth Accountability Testing System (CATS) writing portfolios had improved in comparison with their peers in the past who had not done the writing…

  15. Comparative study of phytosterol derivatives in monovarietal olive oils.

    PubMed

    Gómez-Coca, Raquel B; Fernandes, Gabriel D; Del Aguila-Sánchez, Chellah; Pérez-Camino, María Del Carmen; Moreda, Wenceslao

    2014-06-18

    Plant sterols and their derivatives are minor compounds that have been extensively studied in vegetable oils, mainly in olive oil, where they are closely related with its identity. The objective of this work is to determine the content of free and esterified steryl glucosides and their profiles in olive oil in relation to different geographical situation of olive orchards, cultivar, farming modality, and sampling time. The orchards under study were located in the outer ring of the submetropolitan area of Madrid (Spain), where olives from Cornicabra, Manzanilla Cacereña, Manzanilla Castellana, and Picual varieties were grown under traditional and organic modes, and harvested in four different samplings. Conclusions state that cultivar, farming mode, and light exposure do not have outstanding effects, whereas pedoclimate might affect the steryl glucoside presence in a substantial way. Further studies are being carried out presently in order to confirm such statement. Also glucoside derivative profiles are discussed, and reasons for differences with results in previous studies pointed out. PMID:24861171

  16. Grandparents Raising Their Grandchildren: A Comparative Study of Depression

    ERIC Educational Resources Information Center

    Strutton, Joan N.

    2010-01-01

    There has been a steady increase in the United States in recent decades of grandparents raising their grandchildren. The aim of this study was to determine if depression levels of grandparents raising their grandchildren and depression levels of traditional grandparents differ. Additionally, the extent of the relationship to depression scores by…

  17. Education in Germany since Unification. Oxford Studies in Comparative Education.

    ERIC Educational Resources Information Center

    Phillips, David, Ed.

    This collection of papers discusses issues related to education in Germany since its unification. The papers include: "The Legacy of Unification" (David Phillips); "Change and Continuity in Education After the 'Wende'" (E. J. Neather); "A Study of Teachers' Perceptions in Brandenburg 'Gesamtschulen'" (Stephanie Wilde); "Memory and Judgement: How…

  18. Englishes in the Outer and Expanding Circles: A Comparative Study

    ERIC Educational Resources Information Center

    Davydova, Julia

    2012-01-01

    The major objective of the study is to develop a framework allowing for the systematic investigation of the institutionalised varieties and performance varieties of English (also known as learner Englishes). This involves a detailed description of the forms of English spoken in India and in Russia as well as discussion of sociolinguistic histories…

  19. Principal Leadership and Mathematics Achievement: An International Comparative Study

    ERIC Educational Resources Information Center

    Shin, Seon-Hi; Slater, Charles L.

    2010-01-01

    This study investigated the differences and similarities in the impact of school leadership on student mathematics achievement in different global regions using TIMSS international data. Three-level unconditional and conditional hierarchical models were fitted to the data in each country. The findings showed that the variables of teacher…

  20. Entering Student Affairs: A Comparative Study of Graduate School Choice

    ERIC Educational Resources Information Center

    Mertz, Norma; Eckman, Ellen; Strayhorn, Terrell

    2012-01-01

    This article describes the college choice process of graduate students in College Student Personnel programs at a public university and a private religiously affiliated university. Despite differences in size, mission, and location of the two institutions studied, the research findings show that respondent populations were similar demographically…

  1. Adolescent Literacy and School Structure: A Comparative Case Study

    ERIC Educational Resources Information Center

    Codispoti, Marie

    2010-01-01

    Students who leave elementary school after fourth grade may not be receiving adequate literacy instruction. Although many recent studies have focused on a drop in test scores for middle school students, a gap exists in the literature with regard to explicit literacy instruction in elementary and non-elementary school settings. To inform educators…

  2. Comparative study of switchgrass cultivars using RNA sequencing technology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Switchgrass (Panicum virgatum L.) is a C4 perennial grass, identified as a promising bioenergy crop. Switchgrass exists in two ecotypes, upland and lowland, which are heterotic, or genetically complementary to each other. The objectives of this study are to assess the potential of SNP markers as a b...

  3. Effective Teacher Characteristics: A Two Nation Causal Comparative Study

    ERIC Educational Resources Information Center

    Elliott, Bianca Lynn Shindley

    2010-01-01

    School administrators who recruit teachers domestically and abroad lack an internationally accepted checklist for effective teachers with which to evaluate teacher applicants. This study was conducted to use the elements of a U.S.-based effective teacher checklist survey with a sample of secondary teachers in Guatemala and Japan to describe the…

  4. A Comparative Study of Small Group Fluency Instruction

    ERIC Educational Resources Information Center

    Kuhn, Melanie

    2005-01-01

    The present study investigated the reading development of small groups of learners making the transition from intentional decoding to fluent reading. The research focused on the relative effectiveness of repeated and wide reading as a means of developing reading fluency. It also looked at the importance of expressive, or prosodic, reading in…

  5. A Comparative Study of Three Revision Methods in EFL Writing

    ERIC Educational Resources Information Center

    Srichanyachon, Napaporn

    2011-01-01

    In an attempt to explore effective instruction in the English as a Foreign Language (EFL) setting, this study investigated language errors identified by students and teachers in three different revision stages: self-revision, peer revision, and teacher revision. It gave the focus to the effects of the three different methods on learners' writing…

  6. Automated Versus Conventional Systematic Desensitization: A Study of Comparative Effectiveness.

    ERIC Educational Resources Information Center

    De Csipkes, Robert A.; Rowe, Wayne

    This study investigates whether variations in method of presentation of anxiety items (experimenter's voice, experimenter's taped voice, subject's taped voice) will result in differences in autonomic arousal (as measured by self-report, galvanic skin response, cardiac rate, blood pressure). Ss were 24 Naval Academy midshipmen. The procedure…

  7. Library Abuse in Academic Institutions: A Comparative Study.

    ERIC Educational Resources Information Center

    Obiagwu, Marcel C.

    1992-01-01

    Describes a study that investigated the abuse of library materials through theft, mutilation, unauthorized borrowing, and vandalism at the University of Port Harcourt (Nigeria) and King Fahd University of Petroleum and Minerals (Saudi Arabia). Motivations for abuse are discussed, and recommendations for improved collection protection are…

  8. A Comparative Study of Super-Earth Atmospheres

    NASA Astrophysics Data System (ADS)

    Dragomir, Diana; Benneke, Bjoern; Crossfield, Ian; Howard, Andrew; Knutson, Heather

    2014-12-01

    Ongoing transit surveys such as Kepler have resulted in the discovery of more than a dozen super?Earth planets with measured masses and radii. These planets are challenging targets for atmospheric characterization studies, and to date only one (GJ 1214b) has been studied in detail. In this proposal we focus on three additional super-Earths that are amenable to transmission spectroscopy studies due to their bright host stars (HD 97658b and 55 Cnc e) or their exceptionally low density (Kepler-138d). Our Spitzer measurements of these planets' transit depths will complement our already approved HST observations and contribute to distinguishing between clear hydrogen?dominated atmospheres and compact high-metallicity atmospheres, as well as constraining the composition of any high-altitude clouds. We will also search for evidence of carbon-bearing molecules, in particular for 55 Cnc e, a planet for which a carbon-rich composition has been suggested. Our observations will probe the poorly understood transition region between gas giant planets and terrestrial worlds, and provide constraints on the formation regions of these super-Earths. The results of this program will inform the direction to be taken by large-scale studies of these worlds with JWST.

  9. Age and Workers' Perceptions of Workplace Safety: A Comparative Study

    ERIC Educational Resources Information Center

    Gyekye, Seth Ayim; Salminen, Simo

    2009-01-01

    The study examined the relationship between age and I) safety perception; ii) job satisfaction; iii) compliance with safety management policies; and (iv) accident frequency. Participants were Ghanaian industrial workers (N = 320) categorized into 4 age groups: 19-29 years; 30-39 years; 40-50 years; and 51 years and above. Workplace safety…

  10. A Case History and Comparative Study of a Multiple Personality.

    ERIC Educational Resources Information Center

    Boor, Myron

    The study of multiple personality is important because this disorder is severely disruptive to the individual and because further insights into other behavior disorders and the development of normal personality and behavioral functioning may emerge. A 26-year-old female experienced a conscious personality which determined the extent to which both…

  11. The Management of Training in Multinational Corporations: Comparative Case Studies.

    ERIC Educational Resources Information Center

    Noble, Charles

    1997-01-01

    Case studies of British and Australian multinational corporations in the food and drink industry investigated how training and development are managed. Competency-based education and industry boards are important elements in both countries. Lack of a training culture in the industry and little innovation in training were observed. (SK)

  12. A Comparative Study of Electronic Performance Support Systems

    ERIC Educational Resources Information Center

    Nguyen, Frank; Klein, James D.; Sullivan, Howard

    2005-01-01

    Electronic performance support systems (EPSS) deliver relevant support information to users while they are performing tasks. The present study examined the effect of different types of EPSS on user performance, attitudes, system use and time on task. Employees at a manufacturing company were asked to complete a procedural software task and…

  13. Operations: A Comparative Study of the United States and Taiwan

    ERIC Educational Resources Information Center

    Lin, Cheng-Yao; Becker, Jerry; Byun, Mi-Ran; Yang, Der-Ching; Huang, Tsai-Wei

    2013-01-01

    This study examined (a) the differences in preservice teachers’ procedural knowledge in four areas of fraction operations in Taiwan and the United States, (b) the differences in preservice teachers’ conceptual knowledge in four areas of fraction operations in Taiwan and the United States, and (c) correlation in preservice teachers’ conceptual…

  14. A Comparative Analysis of Mediated Instruction: An Exploratory Study.

    ERIC Educational Resources Information Center

    Brillantes, Robbie M.; And Others

    A study examined instructional television (ITV) to determine the differences in the affect domain existing among three concurrent environments: the face-to-face environment, defined as the site from which the message originates; the on-site location, defined as a location in close proximity to the origin of the message; and the off-site location.…

  15. Asperger Syndrome and Schizophrenia: A Comparative Neuropsychological Study.

    PubMed

    Marinopoulou, Maria; Lugnegård, Tove; Hallerbäck, Maria Unenge; Gillberg, Christopher; Billstedt, Eva

    2016-07-01

    There has been an increasing interest in possible connections between autism spectrum disorder (ASD) and schizophrenia in the last decade. Neuropsychological comparison studies have, however, been few. The present study examined similarities and differences in intellectual and executive functioning between adults with Asperger syndrome (AS) and adults with schizophrenic psychosis (SP). A group with AS and a group with SP were assessed neuropsychologically with WAIS-III and D-KEFS. Similarities were found between groups, as displayed by an uneven cognitive profile, limitations in working memory, processing speed and some aspects of executive functioning. Full Scale IQ was higher in the AS group. These results add to the current research illuminating similarities and differences between ASD and schizophrenia on a cognitive level. PMID:26936160

  16. Comparative study viruses with computer-aided phase microscope AIRYSCAN

    NASA Astrophysics Data System (ADS)

    Tychinsky, Vladimir P.; Koufal, Georgy E.; Perevedentseva, Elena V.; Vyshenskaia, Tatiana V.

    1996-12-01

    Traditionally viruses are studied with scanning electron microscopy (SEM) after complicated procedure of sample preparation without the possibility to study it under natural conditions. We obtained images of viruses (Vaccinia virus, Rotavirus) and rickettsias (Rickettsia provazekii, Coxiella burnetti) in native state with computer-aided phase microscope airyscan -- the interference microscope of Linnik layout with phase modulation of the reference wave with dissector image tube as coordinate-sensitive photodetector and computer processing of phase image. A light source was the He-Ne laser. The main result is coincidence of dimensions and shape of phase images with available information concerning their morphology obtained with SEM and other methods. The fine structure of surface and nuclei is observed. This method may be applied for virus recognition and express identification, investigation of virus structure and the analysis of cell-virus interaction.

  17. Comparative micro computed tomography study of a vertebral body

    NASA Astrophysics Data System (ADS)

    Drews, Susanne; Beckmann, Felix; Herzen, Julia; Brunke, Oliver; Salmon, Phil; Friess, Sebastian; Laib, Andres; Koller, Bruno; Hemberger, Thomas; Müller-Gerbl, Magdalena; Müller, Bert

    2008-08-01

    Investigations of bony tissues are often performed using micro computed tomography based on X-rays, since the calcium distribution leads to superior contrast. Osteoporotic bone, for example, can be well compared with healthy one with respect to density and morphology. Degenerative and rheumatoid diseases usually start, however, at the bone-cartilage-interface, which is hardly accessible. The direct influence on the bone itself becomes only visible at later stage. For the development of suitable therapies against degenerative cartilage damages the exact three-dimensional description of the bone-cartilage interface is vital, as demonstrated for transplanted cartilage-cells or bone-cartilage-constructs in animal models. So far, the morphological characterization was restricted to magnetic resonance imaging (MRI) with poor spatial resolution or to time-consuming histological sectioning with appropriate spatial resolution only in two rather arbitrarily chosen directions. Therefore, one should develop μCT to extract the features of low absorbing cartilage. The morphology and the volume of the inter-vertebral cartilage disc of lumbar motion segments have been determined for one PMMA embedded specimen. Tomograms were recorded using nanotom® (Phoenix|x-ray, Wunstorf, Germany), μCT 35TM (Scanco Medical, Brütisellen, Switzerland), 1172TM and 1174TM (both Skyscan, Kontich, Belgium), as well as using the SRμCT at HASYLAB/DESY. Conventional and SRμCT can provide the morphology and the volume of cartilage between bones. Increasing the acquisition time, the signal-to-noise ratio becomes better and better but the prominent artifacts in conventional μCT as the result of inhomogeneously distributed bony tissue prevents the exact segmentation of cartilage. SRμCT allows segmenting the cartilage but requires long periods of expensive beam-time to obtain reasonable contrast.

  18. a Comparative Study of Sfxts and Long-Period Pulsars

    NASA Astrophysics Data System (ADS)

    Sasano, Makoto; Enoto, Teruaki; Makishima, Kazuo; Yamada, Shinya; Nakazawa, Kazuhiro; Yuasa, Takayuki

    2012-07-01

    Super-giant Fast X-ray Transients (SFXTs), composed of super-giant stars and highly magnetized neutron stars, are characterized by a rather low luminosity in quiescence and very drastic flares. However, these features are also observed, at least to some extent, from other types of HMXBs, including in particular binary pulsars with long pulse periods (>1000 sec). Through wide-band spectroscopy with Suzaku, we aim at a comparison between SFXTs and long-period pulsars, with particular emphasis on the possibility that both have strong magnetic fields. So far, several SFXTs were observed with Suzaku, including IGR J16195-4945 in particular. We re-analyze the archival Suzaku data of this object, obtained on 2006 September 20 for 39 ksec. As reported by Morris et al. (2009), a prominent flare lasting for 10 ksec was recorded in the XIS (1- 10 keV) and HXD (12 - 40 keV) data. We found that the absorbing column density remained the same within ~10 % during the flare. Moreover, the flare was accompanied by weakening or broadening of the fluorescent Fe-K line. These results are inconsistent with the popular SFXT scenario that clumpy stellar winds occur flares. Instead, they prefer an alternative scenario of ``magnetic gating", which assumes the neutron star like magnetars Using Suzaku, we also analyzed the long-period pulsar 4U0114+65 on 2011 July 11 for 100 ksec. The XIS and the HXD detected clear flaring behavior. the known period of ˜10,000 sec which is indicative of strong magnetic field like magnetars was observed. We obtained spectra, with a clear fluorescent Fe-K line, over a very broad (1-100 keV) band From these results, we compare properties of SFXTs and long period pulsars, and discuss their possible relations to magnetars.

  19. Comparative study of radiation damage accumulation in Cu and Fe

    NASA Astrophysics Data System (ADS)

    Caturla, M. J.; Soneda, N.; Alonso, E.; Wirth, B. D.; Díaz de la Rubia, T.; Perlado, J. M.

    2000-01-01

    Bcc and fcc metals exhibit significant differences in behavior when exposed to neutron or heavy ion irradiation. Transmission electron microscopy (TEM) observations reveal that damage in the form of stacking fault tetrahedra (SFT) is visible in copper irradiated to very low doses, but that no damage is visible in iron irradiated to the same total dose. In order to understand and quantify this difference in behavior, we have simulated damage production and accumulation in fcc Cu and bcc Fe. We use 20 keV primary knock-on atoms (PKAs) at a homologous temperature of 0.25 of the melting point. The primary damage state was calculated using molecular dynamics (MD) with empirical, embedded-atom interatomic potentials. Damage accumulation was modeled using a kinetic Monte Carlo (kMC) algorithm to follow the evolution of all defects produced in the cascades. The diffusivities and binding energies of defects are input data for this simulation and were either extracted from experiments, the literature, or calculated using MD. MD simulations reveal that vacancy clusters are produced within the cascade core in the case of copper. In iron, most of the vacancies do not cluster during cooling of the cascade core and are available for diffusion. In addition, self-interstitial atom (SIA) clusters are produced in copper cascades but those observed in iron are smaller in number and size. The combined MD/kMC simulations reveal that the visible cluster densities obtained as a function of dose are at least one order of magnitude lower in Fe than in Cu. We compare the results with experimental measurements of cluster density and find excellent agreement between the simulations and experiments when small interstitial clusters are considered to be mobile as suggested by recent MD simulations.

  20. Comparative study of normal and sensitive skin aerobic bacterial populations

    PubMed Central

    Hillion, Mélanie; Mijouin, Lily; Jaouen, Thomas; Barreau, Magalie; Meunier, Pauline; Lefeuvre, Luc; Lati, Elian; Chevalier, Sylvie; Feuilloley, Marc G J

    2013-01-01

    The purpose of this study was to investigate if the sensitive skin syndrome, a frequent skin disorder characterized by abnormal painful reactions to environmental factors in the absence of visible inflammatory response, could be linked to a modification in the skin bacterial population. A total of 1706 bacterial isolates was collected at the levels of the forehead, cheekbone, inner elbow, and lower area of the scapula on the skin of normal and sensitive skin syndrome-suffering volunteers of both sexes and of different ages. Among these isolates, 21 strains were randomly selected to validate in a first step the Matrix-Assisted Laser Desorption/Ionization (MALDI)-Biotyper process as an efficient identification tool at the group and genus levels, by comparison to API® strips and 16S ribosomal RNA gene sequencing identification techniques. In a second step, identification of the skin microbiota isolates by the MALDI-Biotyper tool allowed to pinpoint some differences in terms of bacterial diversity with regard to the collection area, and the volunteer's age and gender. Finally, comparison of the skin microbiota from normal and sensitive skin syndrome-suffering volunteers pointed out gender-related variations but no detectable correlation between a phylum, a genus or a dominant bacterial species and the sensitive skin phenotype. This study reveals that there is no dysbiosis of aerobic cultivable bacteria associated with the sensitive skin syndrome and further demonstrates that the MALDI-Biotyper is a powerful technique that can be efficiently employed to the study of cultivable human skin bacteria. To our knowledge, this is the first study focusing on bacteria in the sensitive skin syndrome. These results are of potential importance for pharmaceutical and cosmetic industries, which are looking for new strategies to treat this multiparametric disorder. PMID:24151137

  1. Comparative study of normal and sensitive skin aerobic bacterial populations.

    PubMed

    Hillion, Mélanie; Mijouin, Lily; Jaouen, Thomas; Barreau, Magalie; Meunier, Pauline; Lefeuvre, Luc; Lati, Elian; Chevalier, Sylvie; Feuilloley, Marc G J

    2013-12-01

    The purpose of this study was to investigate if the sensitive skin syndrome, a frequent skin disorder characterized by abnormal painful reactions to environmental factors in the absence of visible inflammatory response, could be linked to a modification in the skin bacterial population. A total of 1706 bacterial isolates was collected at the levels of the forehead, cheekbone, inner elbow, and lower area of the scapula on the skin of normal and sensitive skin syndrome-suffering volunteers of both sexes and of different ages. Among these isolates, 21 strains were randomly selected to validate in a first step the Matrix-Assisted Laser Desorption/Ionization (MALDI)-Biotyper process as an efficient identification tool at the group and genus levels, by comparison to API(®) strips and 16S ribosomal RNA gene sequencing identification techniques. In a second step, identification of the skin microbiota isolates by the MALDI-Biotyper tool allowed to pinpoint some differences in terms of bacterial diversity with regard to the collection area, and the volunteer's age and gender. Finally, comparison of the skin microbiota from normal and sensitive skin syndrome-suffering volunteers pointed out gender-related variations but no detectable correlation between a phylum, a genus or a dominant bacterial species and the sensitive skin phenotype. This study reveals that there is no dysbiosis of aerobic cultivable bacteria associated with the sensitive skin syndrome and further demonstrates that the MALDI-Biotyper is a powerful technique that can be efficiently employed to the study of cultivable human skin bacteria. To our knowledge, this is the first study focusing on bacteria in the sensitive skin syndrome. These results are of potential importance for pharmaceutical and cosmetic industries, which are looking for new strategies to treat this multiparametric disorder. PMID:24151137

  2. Effect of Orthostasis on Endothelial Function: A Gender Comparative Study

    PubMed Central

    Goswami, Nandu; Gorur, Paavan; Pilsl, Ulrike; Anyaehie, Bond; Green, David A.; Bondarenko, Alexander I.; Roessler, Andreas; Hinghofer-Szalkay, Helmut G.

    2013-01-01

    As the vascular endothelium has multiple functions, including regulation of vascular tone, it may play a role in the pathophysiology of orthostatic intolerance. We investigated the effect of orthostasis on endothelial function using EndoPAT®, a non-invasive and user-independent method, and across gender. As sex steroid hormones are known to affect endothelial function, this study examined the potential effect of these hormones on the endothelial response to orthostasis by including females at different phases of the menstrual cycle (follicular and luteal—where the hormone balance differs), and females taking an oral contraceptive. A total of 31 subjects took part in this study (11 males, 11 females having normal menstrual cycles and 9 females taking oral contraceptive). Each subject made two visits for testing; in the case of females having normal menstrual cycles the first session was conducted either 1–7 (follicular) or 14–21 days (luteal) after the start of menstruation, and the second session two weeks later, i.e., during the other phase, respectively. Endothelial function was assessed at baseline and following a 20-min orthostatic challenge (active standing). The EndoPAT® index increased from 1.71 ± 0.09 (mean ± SEM) at baseline to 2.07 ± 0.09 following orthostasis in females (p<0.001). In males, the index increased from 1.60 ± 0.08 to 1.94 ± 0.13 following orthostasis (p<0.001). There were no significant differences, however, in the endothelial response to orthostasis between females and males, menstrual cycle phases and the usage of oral contraceptive. Our results suggest an increased vasodilatatory endothelial response following orthostasis in both females and males. The effect of gender and sex hormones on the endothelial response to orthostasis appears limited. Further studies are needed to determine the potential role of this post orthostasis endothelial response in the pathophysiology of orthostatic intolerance. PMID:24147147

  3. A comparative study of RADAR Ka-band backscatter

    NASA Astrophysics Data System (ADS)

    Mapelli, D.; Pierdicca, N.; Guerriero, L.; Ferrazzoli, Paolo; Calleja, Eduardo; Rommen, B.; Giudici, D.; Monti Guarnieri, A.

    2014-10-01

    Ka-band RADAR frequency range has not yet been used for Synthetic Aperture Radar (SAR) from space so far, although this technology may lead to important applications for the next generation of SAR space sensors. Therefore, feasibility studies regarding a Ka-band SAR instrument have been started [1][2], for the next generation of SAR space sensors. In spite of this, the lack of trusted references on backscatter at Ka-band revealed to be the main limitation for the investigation of the potentialities of this technology. In the framework of the ESA project "Ka-band SAR backscatter analysis in support of future applications", this paper is aimed at the study of wave interaction at Ka-band for a wide range of targets in order to define a set of well calibrated and reliable Ka-band backscatter coefficients for different kinds of targets. We propose several examples of backscatter data resulting from a critical survey of available datasets at Ka-band, focusing on the most interesting cases and addressing both correspondences and differences. The reliability of the results will be assessed via a preliminary comparison with ElectroMagnetic (EM) theoretical models. Furthermore, in support of future technological applications, we have designed a prototypal software acting as a "library" of earth surface radar response. In our intention, the output of the study shall contribute to answer to the need of a trustworthy Ka-Band backscatter reference. It will be of great value for future technological applications, such as support to instrument analysis, design and requirements' definition (e.g.: Signal to Noise Ratio, Noise Equivalent Sigma Zero).

  4. HRTEM study comparing naturally and experimentally weathered pyroxenoids

    SciTech Connect

    Banfield, J.F.; Ferruzzi, G.G.; Casey, W.H.; Westrich, H.R.

    1995-01-01

    The mineralogy and chemistry of both naturally and experimentally weathered MnSiO{sub 3} chain silicate minerals (rhodonite and pyroxmangite) were compared. In natural MnSiO{sub 3}, high-resolution transmission-electron microscope observations reveal that alteration begins at grain boundaries and planar defects parallel to the silicate chains that represent junctions between regions with different chain periodicities. Dissolution along these defects results in elongate etch pits that may be partly filled by smectite. Smectite (Ca{sub 0.3}Mn{sub 2}Zn{sub 0.4}Al{sub 0.1}Si{sub 4}O{sub 10}(OH){sub 2}) also develops in larger etches at grain boundaries. The Zn apparently released by weathering of coexisting sphalerite, may facilitate crystallization of manganese-smectite; rhodochrosite is also an initial product. X-ray diffraction patterns from highly altered materials reveal only rhodochrosite and quartz. Simplified reactions are H{sub 2}CO{sub 3}(aq) + 4 MnSiO{sub 3}(s) = Mn{sub 3}Si{sub 4}O{sub 10}(OH){sub 2}(s) + MnCO{sub 3}(s) accompanied by 3H{sub 2}CO{sub 3}(aq) + Mn{sub 3}Si{sub 4}O{sub 10}(OH){sub 2}(s) = 3 MnCO{sub 3}(s) + 4SiO{sub 2}(s) + 4H{sub 2}O. Pyroxenoid dissolution is incongruent under experimental conditions. A 3-7 nm-thick layer of amorphous silica is present at the mineral surface after {approximately}2000 h of reaction in acidic and near-neutral pH solutions that were undersaturated with respect to bulk amorphous silica. This thin layer of polymeric silica, which is absent on unreacted grains, is interpreted to have formed largely by incongruent dissolution at the mineral surface as protons in solution rapidly exchange for near-surface Mn. The layer may also contain silica readsorbed back onto the surface from solution. The net result is that silica from the pyroxenoid is redistributed directly into reaction products. Upon aging in air for a year, leached layers partially recrystallize.

  5. Comparative study of the tritium distribution in metals

    NASA Astrophysics Data System (ADS)

    Perevezentsev, A. N.; Bell, A. C.; Rivkis, L. A.; Filin, V. M.; Gushin, V. V.; Belyakov, M. I.; Bulkin, V. I.; Kravchenko, I. M.; Ionessian, I. A.; Torikai, Y.; Matsuyama, M.; Watanabe, K.; Markin, A. I.

    2008-01-01

    Coupons of stainless steel, Inconel, beryllium, copper and aluminium bronze were exposed to tritium in hydrogen gas mixtures over a wide range of parameters: temperature up to 770 K, pressure from 1 × 10 -4 MPa to 0.05 MPa, tritium concentration from 1 at.% to 98 at.%. The tritium concentration on the surface and distribution through the metals were measured using radiography, radioluminography, β-ray induced X-ray spectroscopy and acid etching methods. The effect of metal processing, such as forging, polishing and heat treatment on the tritium distribution was studied along with parameters relating to the exposure of the metal to tritium.

  6. A comparative study of a new cardiotocography analysis program.

    PubMed

    Chen, Chen-Yu; Chen, Ju-Cheng; Yu, Chun; Lin, Chii-Wann

    2009-01-01

    Cardiotocography (CTG) is a frequently used technique of fetal monitoring to evaluate the well being of the fetus during pregnancy and in labor. The surveillance technique depends on the analysis of characteristic fetal heart rate patterns and uterine contractions. Computerized analyses can mitigate the intra-observer and inter-observer variability of visual CTG recording explanation, decrease the examination time, and the need of additional tests for fetal health. Several studies also showed that the signal processing techniques could help to determine the fetal heart rate (FHR) patterns, but all of them were only suitable for physicians. Following the criteria and consensuses of National Institute of Child Health and Human Development in April 2008, we developed a LabVIEW based FHR and uterine contraction (UC) pattern analysis software. This software has great potential for home-care use. The signal processing methods utilized in this study are median filter and peak/valley detection method. The analysis performance was verified by nineteen pregnant women's data. The accuracy of FHR baseline, baseline variability, early deceleration, UC frequency and NST all reach 100%. The accuracy of acceleration frequency reaches 90%. The accuracy of late and variable decelerations reaches 95%. PMID:19965213

  7. Electrorefining of carbothermic and carbonitrothermic vanadium: a comparative study

    SciTech Connect

    Tripathy, P.K.; Rakhasia, R.H.; Hubli, R.C.; Suri, A.K

    2003-06-19

    Electrorefining is a very effective technique for transforming impure vanadium to a state of high purity. Besides being semi-continuous in nature, this process removes all the interstitial impurities to well below their respective tolerable limits, together with a number of commonly associated metallic impurities. Among different types of vanadium materials used for anode feed, carbothermic vanadium is not only relatively, less costly and easy to prepare, but also could be electrorefined into high purity vanadium. However, the presence of relatively high amount of carbon in the anode feed critically affects the electrorefining process resulting in lesser purity and poorer recovery of the vanadium. In the present study, a low-cost vanadium intermediate, essentially a solid solution of vanadium, nitrogen, carbon and oxygen was studied for electrorefining. The anode feed, containing {approx}94% vanadium, was prepared by nitridation-cum-denitridation of a mixture, comprised of V{sub 2}O{sub 5} and petroleum coke powders. The electrorefining was carried out in a LiCl-KCl-VCl{sub 2} bath at 893 K under high purity argon atmosphere. The current efficiency, vanadium recovery and purity were 90, 86, and 99.85%, respectively.

  8. Comparative study of spray booth filter system efficiency

    SciTech Connect

    Darvin, C.H.; Cox, L.S.; Smith, D.

    1997-12-31

    During recent years, greater emphasis has been placed on the control of particulate emissions from painting operations. This has gained importance as more is learned about the potential release of toxic metals to the atmosphere from painting operations. This has led to queries about the efficiency of various painting arrestor systems to reduce particulate discharges to the atmosphere. Even more important is the capability of the arrestor systems to control PM-10 emissions. In 1995, the USEPA initiated a study to evaluate various dry paint overspray arrestor systems. This study was designed to evaluate, not only the total emissions control capability of the arrestor, but also the PM-10 control capability of the various system designs. Paint overspray arrestor systems using five different filtration concepts and/or materials were selected. They include systems constructed of fiberglass, paper, styrofoam, and cardboard. These systems used filtration techniques incorporating the following filtration phenomena and designs: cyclone, baffle, bag systems, and mesh systems. The testing used an optical particle counting procedure to determine the concentration of particles of a given size fraction to penetrate a test arrestor system. The results of the testing indicated that there are significant differences in the efficiency of the tested system designs to capture and retain PM-10. This paper summarizes the results of the research conducted to determine the capability of the arrestor systems to capture particulate of particle sizes down to approximately 1 {micro}m in surface diameter.

  9. A comparative study in ultrasound breast imaging classification

    NASA Astrophysics Data System (ADS)

    Yap, Moi Hoon; Edirisinghe, Eran A.; Bez, Helmut E.

    2009-02-01

    American College of Radiology introduces a standard in classification, the breast imaging reporting and data system (BIRADS), standardize the reporting of ultrasound findings, clarify its interpretation, and facilitate communication between clinicians. The effective use of new technologies to support healthcare initiatives is important and current research is moving towards implementing computer tools in the diagnostics process. Initially a detailed study was carried out to evaluate the performance of two commonly used appearance based classification algorithms, based on the use of Principal Component Analysis (PCA), and two dimensional linear discriminant analysis (2D-LDA). The study showed that these two appearance based classification approaches are not capable of handling the classification of ultrasound breast image lesions. Therefore further investigations in the use of a popular feature based classifier - Support Vector Machine (SVM) was conducted. A pre-processing step before feature based classification is feature extraction, which involve shape, texture and edge descriptors for the Region of Interest (ROI). The input dataset to SVM classification is from a fully automated ROI detection. We achieve the success rate of 0.550 in PCA, 0.500 in LDA, and 0.931 in SVM. The best combination of features in SVM classification is to combine the shape, texture and edge descriptors, with sensitivity 0.840 and specificity 0.968. This paper briefly reviews the background to the project and then details the ongoing research. In conclusion, we discuss the contributions, limitations, and future plans of our work.

  10. A comparative study of different ferrofluid constitutive equations.

    NASA Astrophysics Data System (ADS)

    Kaloni, Purna

    2011-11-01

    Ferrofluids are stable colloidal suspensions of fine ferromagnetic monodomain nanoparticles in a non-conducting carrier fluid. The particles are coated with a surfacant to avoid agglomeration and coagulation.Brownian motion keeps the nanoparticles from settling under gravity. In recent years these fluids have found several applications including in liquid seals in rotary shafts for vacuum system and in hard disk drives of personal computers, in cooling and damping of loud speakers, in shock absorbers and in biomedical applications. A continuum description of ferrofluids was initiated by Neuringer and Rosensweig but the theory had some limitations. In subsequent years,several authors have proposed generalization of the above theory.Some of these are based upon the internal particle rotation concept, some are phemonological, some are based upon a thermodynamic framework, some employ statistical approach and some have used the dynamic mean field approach. The results based upon these theories ane in early stages and inconclusive. Our purpose is, first, to critically examine the basic foundations of these equations and then study the pedictions obtained in all the theories related to an experimental as well as a theoretical study.

  11. A comparative study of dipolarization fronts at MMS and Cluster

    NASA Astrophysics Data System (ADS)

    Schmid, D.; Nakamura, R.; Volwerk, M.; Plaschke, F.; Narita, Y.; Baumjohann, W.; Magnes, W.; Fischer, D.; Eichelberger, H. U.; Torbert, R. B.; Russell, C. T.; Strangeway, R. J.; Leinweber, H. K.; Le, G.; Bromund, K. R.; Anderson, B. J.; Slavin, J. A.; Kepko, E. L.

    2016-06-01

    We present a statistical study of dipolarization fronts (DFs), using magnetic field data from MMS and Cluster, at radial distances below 12 RE and 20 RE, respectively. Assuming that the DFs have a semicircular cross section and are propelled by the magnetic tension force, we used multispacecraft observations to determine the DF velocities. About three quarters of the DFs propagate earthward and about one quarter tailward. Generally, MMS is in a more dipolar magnetic field region and observes larger-amplitude DFs than Cluster. The major findings obtained in this study are as follows: (1) At MMS ˜57 % of the DFs move faster than 150 km/s, while at Cluster only ˜35 %, indicating a variable flux transport rate inside the flow-braking region. (2) Larger DF velocities correspond to higher Bz values directly ahead of the DFs. We interpret this as a snow plow-like phenomenon, resulting from a higher magnetic flux pileup ahead of DFs with higher velocities.

  12. FT-IR spectroscopy of lipoproteins—A comparative study

    NASA Astrophysics Data System (ADS)

    Krilov, Dubravka; Balarin, Maja; Kosović, Marin; Gamulin, Ozren; Brnjas-Kraljević, Jasminka

    2009-08-01

    FT-IR spectra, in the frequency region 4000-600 cm -1, of four major lipoprotein classes: very low density lipoprotein (VLDL), low density lipoprotein (LDL) and two subclasses of high density lipoproteins (HDL 2 and HDL 3) were analyzed to obtain their detailed spectral characterization. Information about the protein domain of particle was obtained from the analysis of amide I band. The procedure of decomposition and curve fitting of this band confirms the data already known about the secondary structure of two different apolipoproteins: apo A-I in HDL 2 and HDL 3 and apo B-100 in LDL and VLDL. For information about the lipid composition and packing of the particular lipoprotein the well expressed lipid bands in the spectra were analyzed. Characterization of spectral details in the FT-IR spectrum of natural lipoprotein is necessary to study the influence of external compounds on its structure.

  13. Konik and Hucul horses: a comparative study of exterior measurements.

    PubMed

    Komosa, M; Purzyc, H

    2009-07-01

    An exterior comparison was made between 2 primitive horse breeds: the Konik and the Hucul breeds. Each animal was characterized using 25 measurements and 24 indices. Statistical methods employed in this study were principal components analysis and the Student's t-test. It was found that in spite of both breeds being included in the group of horses with a primitive exterior, the Konik and the Hucul possess completely different metric properties of their body conformations. Although the mean height for the Hucul breed slightly exceeds that of the Konik, the latter has longer scapulae and metacarpi. The hind limb also features different proportions among its segments in the 2 breeds. The observed differences seem to be connected with different habitats for these breeds. In particular, mountainous conditions may have had an effect on the specific body conformation of the Hucul breed. PMID:19329479

  14. Comparative study on volatile components of Nardostachys rhizome.

    PubMed

    Tanaka, Ken; Komatsu, Katsuko

    2008-01-01

    Volatile components in 13 crude drug samples derived from Nardostachys chinensis or Nardostachys grandiflora were studied by solid phase micro extraction (SPME)-GC and SPME-GC-MS. Twenty-three compounds accounting for 81.3 and 70.0% of volatile components in newly collected samples of two species were identified. beta-Maaliene, 9-aristolene, calarene and patchouli alcohol were identified as the major volatile constituents of N. chinensis, whereas aromadendrene, cube-11-ene, epi-alpha-selinene, spirojatamol and valeranone were identified as those of N. grandiflora. Using the peaks of beta-maaliene and 9-aristolene in GC profiles as the marker, two Nardostachys species were clearly distinguished among the samples examined. PMID:18404355

  15. Comparative study between Botucatu and Berea sandstone properties

    NASA Astrophysics Data System (ADS)

    Cardoso, Oldemar Ribeiro; Balaban, Rosangela de Carvalho

    2015-10-01

    The aim of the present study is the analysis and comparison between Berea and Botucatu sandstone, concerning the problems with regard to the loss of permeability or water sensitivity or loss of hydraulic conductivity due to the presence of swelling or non-swelling clays. Some porous volumes of synthetic seawater of different salinities were displaced through the porous media of Berea and Botucatu formations. It was observed that even the plugs of Berea, with no-swelling clays in their composition, had the permeability reduced as soon as the brine salinity reached a lower limit. As expected, the same occurred with the Botucatu sandstone samples, however, in this case,the sensitivity to the low salinity was much more effective.

  16. Haloadaptation: insights from comparative modeling studies of halophilic archaeal DHFRs.

    PubMed

    Kastritis, Panagiotis L; Papandreou, Nikos C; Hamodrakas, Stavros J

    2007-10-01

    Proteins of halophilic archaea function in high-salt concentrations that inactivate or precipitate homologous proteins from non-halophilic species. Haloadaptation and the mechanism behind the phenomenon are not yet fully understood. In order to obtain useful information, homology modeling studies of dihydrofolate reductases (DHFRs) from halophilic archaea were performed that led to the construction of structural models. These models were subjected to energy minimization, structural evaluation and analysis. Complementary approaches concerning calculations of the amino acid composition and visual inspection of the surfaces and cores of the models, as well as calculations of electrostatic surface potentials, in comparison to non-halophilic DHFRs were also performed. The results provide evidence that sheds some light on the phenomenon of haloadaptation: DHFRs from halophilic archaea may maintain their fold, in high-salt concentrations, by sharing highly negatively charged surfaces and weak hydrophobic cores. PMID:17675150

  17. Comparative Study of the Labial Gland Secretion in Termites (Isoptera)

    PubMed Central

    Sillam-Dussès, David; Krasulová, Jana; Vrkoslav, Vladimír; Pytelková, Jana; Cvačka, Josef; Kutalová, Kateřina; Bourguignon, Thomas; Miura, Toru; Šobotník, Jan

    2012-01-01

    Labial glands are present in all castes and developmental stages of all termite species. In workers, their secretion contains a food-marking pheromone and digestive enzymes, while soldier secretion plays a defensive role. However, these functions were studied only in a limited set of species, and do not allow drawing general conclusions. Hence, we have investigated the chemical composition of the labial gland extracts from soldiers and workers in 15 termite species belonging to 6 families using an integrative approach based on proteomic and small-molecule profiling. We confirmed the presence of hydroquinone and cellulase in the labial glands of workers, and we identified new toxic compounds in soldiers and workers of several species. Our results highlight the dual role of labial gland secretion, i.e. the defensive role in soldiers and workers of several termite species, and the digestive function in workers. PMID:23071569

  18. The comparative study of particle size distribution in magnetic fluids

    NASA Astrophysics Data System (ADS)

    Timko, M.; Kopčanský, P.; Koneracká, M.; Skumiel, A.; Labowski, M.; Jozefczak, A.; Bica, Doina; Bâlâu, Oana; Vékás, L.; Fannin, P. C.; Giannitsis, A. T.

    2002-01-01

    Water- and physiology-solution-based biocompatible magnetic fluids have been studied in order to determine the size of magnetic particles and their colloidal stability. The results of magnetorheological measurements at room temperature and measurements of the frequency-dependent complex magnetic susceptibility indicate that the fluids have good stability and that the particles are finely dispersed without aggregation. The mean particle diameter for physiology-solution-based magnetic fluid, estimated from measurements of anisttropy of the magnetic susceptibility, was found to be 9.4 nm. This value is in good agreement with an estimate of 11.6 nm obtained from transmission electron microscopy (TEM) particularly when allowance is made for the thickness of surfactant layer (approx. 2 nm).

  19. Using wavelets to solve the Burgers equation: A comparative study

    SciTech Connect

    Schult, R.L.; Wyld, H.W. )

    1992-12-15

    The Burgers equation is solved for Reynolds numbers [approx lt]8000 in a representation using coarse-scale scaling functions and a subset of the wavelets at finer scales of resolution. Situations are studied in which the solution develops a shocklike discontinuity. Extra wavelets are kept for several levels of higher resolution in the neighborhood of this discontinuity. Algorithms are presented for the calculation of matrix elements of first- and second-derivative operators and a useful product operation in this truncated wavelet basis. The time evolution of the system is followed using an implicit time-stepping computer code. An adaptive algorithm is presented which allows the code to follow a moving shock front in a system with periodic boundary conditions.

  20. The comparative study on the flapping motion of Venusian magnetotail

    NASA Astrophysics Data System (ADS)

    Rong, Zhaojin; Barabash, Stas; Wieser Stenberg, Gabriella; Futaana, Yoshifumi; Wan, Weixing; Wei, Yong; Wang, Xiaodong; Chai, Lihui; Zhong, Jun

    2016-04-01

    With a newly developed technique and magnetic field measurements obtained by the magnetometer on Venus Express, we study the flapping motion of the Venusian magnetotail. We find that the flapping motion generally comprises contributions both from a nonpropagating steady flapping and a propagating kink-like flapping. The flapping motion tilts the current sheet normal significantly in the plane perpendicular to the Venus-Sun line. The kink-like flapping waves traveling along solar wind electric field or its antidirection can be found in either magnetotail hemisphere where solar wind electric field pointing toward/away. The traveling behaviors suggest that the locations of the triggers for kink-like flappings are near the boundaries between magnetotail current sheet and magnetosheath, not near the central region of magnetotail as is for the Earth's magnetotail.

  1. Comparative Studies on Plastoquinones. IV. Plastoquinones in Algae

    PubMed Central

    Sun, Elena; Barr, Rita; Crane, F. L.

    1968-01-01

    Plastoquinones A and C have been found in all classes of algae, including representatives of greens, yellow-greens, blue-greens, reds, browns and the flagellate, Euglena. Plastoquinone C from red and brown algae can be separated into 6 different types. An additional plastoquinone C has been found in Gigartina and Rhydomela. From chromatographic evidence this may be equivalent to plastoquinone Co, a C type with a hydroxyl group on the first isoprene unit of the terpenoid sidechain of this substituted benzo-quinone. The ubiquinone, vitamin K and α-tocopherylquinone content of several algae is also reported. The presence of plastoquinone A in all green plants and many algae indicates that it may be a functional element in photosynthesis. Our study shows that plastoquinone C is more regularly present in algae than has been previously shown. PMID:16656993

  2. Comparative study of the labial gland secretion in termites (Isoptera).

    PubMed

    Sillam-Dussès, David; Krasulová, Jana; Vrkoslav, Vladimír; Pytelková, Jana; Cvačka, Josef; Kutalová, Kateřina; Bourguignon, Thomas; Miura, Toru; Šobotník, Jan

    2012-01-01

    Labial glands are present in all castes and developmental stages of all termite species. In workers, their secretion contains a food-marking pheromone and digestive enzymes, while soldier secretion plays a defensive role. However, these functions were studied only in a limited set of species, and do not allow drawing general conclusions. Hence, we have investigated the chemical composition of the labial gland extracts from soldiers and workers in 15 termite species belonging to 6 families using an integrative approach based on proteomic and small-molecule profiling. We confirmed the presence of hydroquinone and cellulase in the labial glands of workers, and we identified new toxic compounds in soldiers and workers of several species. Our results highlight the dual role of labial gland secretion, i.e. the defensive role in soldiers and workers of several termite species, and the digestive function in workers. PMID:23071569

  3. [Comparative study on trace elements in benefit traditional Chinese medicines].

    PubMed

    Fan, Wen-Xiu

    2007-07-01

    The contents of trace elements Zn, Cu, Mn and Fe in 20 kinds of benefit traditional Chinese medicines were determined by FAAS. The recovery rates obtained by standard addition method is between 96.8% and 104.3%, and the RSD is lower than 2.0%. The results of the determination show that benefit traditional Chinese medicines are rich in trace elements such as Zn, Cu, Mn and Fe. Hematonic has the highest content of Fe. The content of Zn, Mn and Fe is relatively high in Qi-invigorating drugs. The content of Zn and Mn is relatively high in maletonic, while Yin-nourishing drugs have lower content of Fe. The results will provide scientific data for the study on the elements in benefit traditional Chinese medicines and on their relativity of efficacy of medicine. PMID:17944431

  4. Comparative study of career development and training programs

    NASA Technical Reports Server (NTRS)

    Tsao, Alan

    1988-01-01

    Improvement of human capital has been identified as the key to any further increase of productivity for any country engaged in the global economic competition. The same can be said of any organization seeking to enhance its overall performance. This study is aimed at: (1) surveying the current practices of career development and training programs at major corporations and government research organizations; (2) presenting the distributions of various program features among survey respondents; (3) identifying the profile of the training program of a typical research organization, against which each organization can check and identify its relative strengths as well as areas needing further strengthening; (4) conducting an economic analysis of the effectiveness of the training programs at Langley Research Center; and (5) making recommendations as to how to enhance existing training programs.

  5. A Comparative Study of Antifungal Activity of Endodontic Irrigants

    PubMed Central

    Mohammadi, Zahed; Asgary, Saeed

    2015-01-01

    Introduction: The purpose of this in vitro study was to assess the antifungal activity of final canal rinse with either three concentrations of sodium hypochlorite (NaOCl) (0.5, 2.6 and 6%), two concentrations of chlorhexidine (CHX) (2% and 0.2%), MTAD, Tetraclean, Hypoclean and Chlor-Xtra on Candida albicans (C. albicans) in a human tooth model. Methods and Materials: Two hundred and thirty five extracted human maxillary central and lateral incisors were used in this study. Teeth were randomly divided into nine test groups (n=25) and positive and a negative control groups (n=5). After cleaning and shaping, teeth were contaminated with C. albicans and incubated for 72 h. The irrigation solution in nine experimental groups included: 6% NaOCl, 2.6% NaOCl, 0.5% NaOCl, 2% CHX, 0.2% CHX, MTAD, Tetraclean, Hypoclean and Chlor-Xtra. After culturing on Sabouraud 4% dextrose agar, colony-forming units (CFU) were counted. Results: 6% NaOCl, 2% CHX and Chlor-Xtra were equally effective (P>0.05) and significantly superior to MTAD and Tetraclean (P<0.05). In addition, the effectiveness of Tetraclean and MTAD was significantly less than Hypoclean, NaOCl at all concentrations (6% 2.6% and 0.5%), MTAD and 0.2% CHX (P<0.05). Furthermore, Tetraclean was significantly more effective than MTAD (P<0.05). Conclusion: Antifungal activity of 6% NaOCl, Chlor-Xtra and 2% CHX was significantly greater than 2.6% NaOCl, 0.5% NaOCl, MTAD, 0.2% CHX and Tetraclean. PMID:25834602

  6. Comparative Analysis Study of Open Source GIS in Malaysia

    NASA Astrophysics Data System (ADS)

    Rasid, Muhammad Zamir Abdul; Kamis, Naddia; Khuizham Abd Halim, Mohd

    2014-06-01

    Open source origin might appear like a major prospective change which is qualified to deliver in various industries and also competing means in developing countries. The leading purpose of this research study is to basically discover the degree of adopting Open Source Software (OSS) that is connected with Geographic Information System (GIS) application within Malaysia. It was derived based on inadequate awareness with regards to the origin ideas or even on account of techie deficiencies in the open origin instruments. This particular research has been carried out based on two significant stages; the first stage involved a survey questionnaire: to evaluate the awareness and acceptance level based on the comparison feedback regarding OSS and commercial GIS. This particular survey was conducted among three groups of candidates: government servant, university students and lecturers, as well as individual. The approaches of measuring awareness in this research were based on a comprehending signal plus a notion signal for each survey questions. These kinds of signs had been designed throughout the analysis in order to supply a measurable and also a descriptive signal to produce the final result. The second stage involved an interview session with a major organization that carries out available origin internet GIS; the Federal Department of Town and Country Planning Peninsular Malaysia (JPBD). The impact of this preliminary study was to understand the particular viewpoint of different groups of people on the available origin, and also their insufficient awareness with regards to origin ideas as well as likelihood may be significant root of adopting level connected with available origin options.

  7. Tissue cholinesterases. A comparative study of their kinetic properties.

    PubMed

    Dave, K R; Syal, A R; Katyare, S S

    2000-01-01

    The substrate saturation and temperature-dependent kinetic properties of soluble and membrane-bound forms of acetylcholinestarase (AChE) from brain and butyrylcholinesterase (BChE) from heart and liver were examined. In simultaneous studies these parameters were also measured for AChE in erythrocyte membranes and for BChE in the serum from rat and humans. For both soluble and membrane-bound forms of the enzyme from the three tissues, two components were discernible. In the brain, Km of component I (high affinity) and component II (low affinity) was somewhat higher in membrane-bound form than that of the soluble form components, while the Vmax values were significantly higher by about five fold. In the heart, Km of component II was lower in membrane-bound form than in the soluble form, while Vmax for both the components was about four to six fold higher in the membrane-bound form. In the liver, Vmax was marginally higher for the two components of the membrane-bound enzyme; the Km only of component I was higher by a factor of 2. In the rat erythrocyte membranes three components of AChE were present showing increasing values of Km and Vmax. In contrast, in the human erythrocyte membranes only two components could be detected; the one corresponding to component II of rat erythrocyte membranes was absent. In the rat serum two components of BChE were present while the human serum was found to possess three components. Component I of the human serum was missing in the rat serum. Temperature kinetics studies revealed that the Arrhenius plots were biphasic for most of the systems except for human serum. Membrane binding of the enzyme resulted in decreased energy of activation with shift in phase transition temperature (Tt) to near physiological temperature. PMID:10739108

  8. Comparative Study of Advanced Turbulence Models for Turbomachinery

    NASA Technical Reports Server (NTRS)

    Hadid, Ali H.; Sindir, Munir M.

    1996-01-01

    A computational study has been undertaken to study the performance of advanced phenomenological turbulence models coded in a modular form to describe incompressible turbulent flow behavior in two dimensional/axisymmetric and three dimensional complex geometry. The models include a variety of two equation models (single and multi-scale k-epsilon models with different near wall treatments) and second moment algebraic and full Reynolds stress closure models. These models were systematically assessed to evaluate their performance in complex flows with rotation, curvature and separation. The models are coded as self contained modules that can be interfaced with a number of flow solvers. These modules are stand alone satellite programs that come with their own formulation, finite-volume discretization scheme, solver and boundary condition implementation. They will take as input (from any generic Navier-Stokes solver) the velocity field, grid (structured H-type grid) and computational domain specification (boundary conditions), and will deliver, depending on the model used, turbulent viscosity, or the components of the Reynolds stress tensor. There are separate 2D/axisymmetric and/or 3D decks for each module considered. The modules are tested using Rocketdyn's proprietary code REACT. The code utilizes an efficient solution procedure to solve Navier-Stokes equations in a non-orthogonal body-fitted coordinate system. The differential equations are discretized over a finite-volume grid using a non-staggered variable arrangement and an efficient solution procedure based on the SIMPLE algorithm for the velocity-pressure coupling is used. The modules developed have been interfaced and tested using finite-volume, pressure-correction CFD solvers which are widely used in the CFD community. Other solvers can also be used to test these modules since they are independently structured with their own discretization scheme and solver methodology. Many of these modules have been

  9. Comparative studies on different nanofiber photocatalysts for water splitting

    NASA Astrophysics Data System (ADS)

    Alharbi, Abdulaziz; Alarifi, Ibrahim M.; Khan, Waseem S.; Asmatulu, Ramazan

    2016-04-01

    Water splitting using photocatalyst has become a topic of recent investigation since it has the potential of producing hydrogen for clean energy from sunlight. An extensive number of solid photocatalysts have been studied for overall water splitting in recent years. In this study, two methods were employed to synthesize two different photocatalysts for water splitting. The first method describes the synthesis of nickel oxide-loaded strontium titanate (NiO-SrTiO3) particles on electrospun polyacrylonitrile (PAN) nanofibers incorporated with graphene nanoplatelets for water splitting. The electrospun PAN fibers were first oxidized at 270°C for two hours and subsequently immersed in a solution containing ethanol, titanium (IV)-isopropoxide [C12H28O4Ti] and strontium nitrate [Sr(NO3)2]. This solution was then treated with NiO nanoparticles dispersed in toluene. The surface treated PAN fibers were annealed at 600°C in air for 1 hour to transform fibers into a crystalline form for improved photocatalyst performance. In the second method, coaxial electrospinning process was used to produce core/shell strontium titanate/nickel oxide (SrTiO3-NiO) nanofibers. In coaxial method, poly (vinyl pyrrolidone) (PVP) was dissolved in deionized (DI) water, and then titanium (IV) isopropoxide [C12H28O4Ti] and strontium nitrate [Sr(NO3)2] were added into the solution to form the inner (core) layer. For outer (shell) solution, polyacrylonitrile (PAN) polymer was dissolved in dimethylformamide (DMF) at a weight ratio of 10:90 and then nickel oxide was mixed with the solution. Ultraviolet (UV) spectrophotometry and static contact angle measurement techniques were employed to characterize the structural properties of photocatalysts produced by both methods and a comparison was made between the two photocatalysts. The morphology and diameter of the nanofibers were observed by scanning electron microscopy (SEM). The structure and crystallinity of the calcined nanofibers were also observed

  10. Cutting Efficiency of Instruments with Different Movements: a Comparative Study

    PubMed Central

    Plotino, Gianluca; Al-Sudani, Dina; Rubini, Alessio Giansiracusa; Sannino, Gianpaolo; Piasecki, Lucila; Putortì, Ermanno; Testarelli, Luca; Gambarini, Gianluca

    2015-01-01

    ABSTRACT Objectives The aim of the present study was to evaluate the cutting efficiency of two new reciprocating instruments, Twisted File Adaptive and WaveOne Primary. Material and Methods 10 new Twisted File Adaptive (TF Adaptive) (SybronEndo, Glendora, CA, USA) and 10 new WaveOne Primary files (Dentsply Maillefer, Ballaigues, Switzerland) were activated using a torque-controlled motor, respectively TFA motor (SybronEndo, Glendora, CA, USA) and Silver motor (VDW, Munich, Germany). The device used for the cutting test consisted on a mainframe to which a mobile plastic support for the hand-piece is connected and a stainless-steel block containing a Plexiglas block against which the cutting efficiency of the instruments was tested. The length of the block cut in 1 minute was measured in a computerized program with a precision of 0.1 mm. Mean and standard deviations of each group were calculated and data were statistically analyzed with one-way ANOVA and Bonferroni t test (P < 0.05). Results TF Adaptive displayed significantly greater maximum penetration depth than WaveOne Primary (P < 0.05). In fact, TF Adaptive instruments (Group 1) cut the Plexiglas block to a mean depth of 8.7 (SD 0.5) mm, while WaveOne Primary instruments cut the Plexiglas block to a mean depth of 6.4 (SD 0.3) mm. Conclusions Twisted File Adaptive instruments demonstrated statistically higher cutting efficiency than WaveOne instruments. PMID:25937877

  11. Comparative studies for serodiagnosis of haemorrhagic septicaemia in cattle sera

    PubMed Central

    El-Jakee, Jakeen K.; Ali, Samah Said; El-Shafii, Soumaya Ahmed; Hessain, Ashgan M.; Al-Arfaj, Abdullah A.; Mohamed, Moussa I.

    2015-01-01

    Haemorrhagic septicaemia caused by Pasteurella multocida is a major epizootic disease in cattle and buffaloes in developing countries with high morbidity and mortality rate. In the present study, a total of 88 P. multocida isolates were isolated from 256 nasopharyngeal swabs and lung tissues samples (34.4%) during the period from January, 2013 to March, 2014 from different governorates located in Egypt. Dead calves showed the highest percentage of P. multocida isolation followed by the emergency slaughtered calves, diseased calves then apparently healthy ones. These isolates were confirmed as P. multocida microscopically, biochemically by traditional tests and by API 20E commercial kit then by PCR. The percentages of positive serum samples using somatic antigen and micro-agglutination test at 1/1280 diluted serum were 10%, 54.49% and 0% in apparently healthy, diseased and emergency slaughtered samples, respectively whereas, the percentages using capsular antigen and indirect haemagglutination test were 40%, 60.89% and 60% in apparently healthy, diseased and emergency slaughtered samples, respectively. The ELISA showed the highest sensitivity for diagnosing P. multocida in apparently healthy, diseased and emergency slaughtered animals with percentages of 42%; 92.9% and 80%, respectively. The obtained results revealed that the ELISA using capsular antigen of P. multocida is a more sensitive and specific serological test for diagnosis of haemorrhagic septicaemia. PMID:26858538

  12. Climate and the eastern repository: A comparative study

    NASA Astrophysics Data System (ADS)

    Michaels, Patrick J.; Stenger, Philip J.; Sappington, David E.

    1987-09-01

    We present a comparison of the climate in prospective states or sites under consideration for the eastern repository for high-level nuclear waste in the United States. We found that atmospheric conditions over several south-eastern sites rank lower than the other prospective areas in effective dispersal, as per Federal Register 10CFR 960.5-2-3 (1984). Also, damage rates in North Carolina and Virginia, and death rates in Virginia, from tropical storms and hurricanes exceed those of the other candidate states. These storms, as well as other mechanisms, subject piedmont Virginia and North Carolina to a high frequency of flash flooding. Death rates from all weather-related causes (including winter storms, tornadoes, and weather-related vehicle accidents) are also highest in Virginia and North Carolina. This finding is rather surprising in light of tornado and blizzard frequencies in northern candidate states. Based upon a 20-year study of damage and mortality figures from the US Department of Commerce publication Storm Data for all weather-related causes, Virginia and North Carolina rank highest. If this is taken as a measure of relative compliance with Federal Register “potentially adverse condition” 960.5-2-3[c][2] pertaining to the history of severe weather phenomena in relation to repository siting, then these states are the least favorable from a climatic viewpoint.

  13. A comparative study of 28 culture media for Trichomonas gallinae

    USGS Publications Warehouse

    Diamond, L.S.

    1954-01-01

    1. 1. A study was made of the ability of 28 different culture media to support growth of 5 strains of Trichomonas gallinae with their normally associated bacteria. A standard inoculum of 50 protozoa was used, and the cultures were incubated at 35 ?C. Based upon the number of positive cultures obtained, abundance of growth, and number of strains which grew in a given medium, the most satisfactory were Ringer-Loeffler serum, saline-Loeffler serum, and saline-serum. 2. 2. Pigeon serum used alone in a simple saline solution produced abundant growth and when added to other nutrients greatly enhanced the medium. Autoclaving of the serum appeared to have no effect on its growth promoting qualities. 3. 3. Neither egg yolk nor egg albumin alone appeared capable of supporting appreciable growth of T. gallinae. 4. 4. In general, the heavier the bacterial population supported by a medium the poorer the growth of T. gallinae. 5. 5. Strains of T. gallinae differ in their culturability. One strain grew in 82% of the media tested, another only in 43%.

  14. Comparative study of the physical properties of core materials.

    PubMed

    Saygili, Gülbin; Mahmali, Sevil M

    2002-08-01

    This study was undertaken to measure physical properties of materials used for direct core buildups, including high-copper amalgam, visible light-cured resin composite, autocured titanium-containing composite, polyacid-modified composite, resin-modified glass-ionomer, and silver cermet cement. Compressive strength, diametral tensile strength, and flexural strength of six core materials of various material classes were measured for each material as a function of time up to 3 months at different storage conditions, using a standard specification test designed for the materials. Three different storage conditions (dry, humid, wet) at 37 degrees C were chosen. Materials were manipulated according to manufacturers' instructions for use as cores. Mean compressive, diametral tensile, and flexural strengths with associated standard deviations were calculated for each material. Multiple comparison and Newman-Keuls tests discerned many differences among materials. All materials were found to meet the minimum specification requirements, except in terms of flexural strength for amalgam after 1 hour and the silver cermet at all time intervals. PMID:12212682

  15. Epigenetic mechanisms and memory strength: a comparative study.

    PubMed

    Federman, Noel; Zalcman, Gisela; de la Fuente, Verónica; Fustiñana, Maria Sol; Romano, Arturo

    2014-01-01

    Memory consolidation requires de novo mRNA and protein synthesis. Transcriptional activation is controlled by transcription factors, their cofactors and repressors. Cofactors and repressors regulate gene expression by interacting with basal transcription machinery, remodeling chromatin structure and/or chemically modifying histones. Acetylation is the most studied epigenetic mechanism of histones modifications related to gene expression. This process is regulated by histone acetylases (HATs) and histone deacetylases (HDACs). More than 5 years ago, we began a line of research about the role of histone acetylation during memory consolidation. Here we review our work, presenting evidence about the critical role of this epigenetic mechanism during consolidation of context-signal memory in the crab Neohelice granulata, as well as during consolidation of novel object recognition memory in the mouse Mus musculus. Our evidence demonstrates that histone acetylation is a key mechanism in memory consolidation, functioning as a distinctive molecular feature of strong memories. Furthermore, we found that the strength of a memory can be characterized by its persistence or its resistance to extinction. Besides, we found that the role of this epigenetic mechanism regulating gene expression only in the formation of strongest memories is evolutionarily conserved. PMID:24978317

  16. Comparative studies for serodiagnosis of haemorrhagic septicaemia in cattle sera.

    PubMed

    El-Jakee, Jakeen K; Ali, Samah Said; El-Shafii, Soumaya Ahmed; Hessain, Ashgan M; Al-Arfaj, Abdullah A; Mohamed, Moussa I

    2016-01-01

    Haemorrhagic septicaemia caused by Pasteurella multocida is a major epizootic disease in cattle and buffaloes in developing countries with high morbidity and mortality rate. In the present study, a total of 88 P. multocida isolates were isolated from 256 nasopharyngeal swabs and lung tissues samples (34.4%) during the period from January, 2013 to March, 2014 from different governorates located in Egypt. Dead calves showed the highest percentage of P. multocida isolation followed by the emergency slaughtered calves, diseased calves then apparently healthy ones. These isolates were confirmed as P. multocida microscopically, biochemically by traditional tests and by API 20E commercial kit then by PCR. The percentages of positive serum samples using somatic antigen and micro-agglutination test at 1/1280 diluted serum were 10%, 54.49% and 0% in apparently healthy, diseased and emergency slaughtered samples, respectively whereas, the percentages using capsular antigen and indirect haemagglutination test were 40%, 60.89% and 60% in apparently healthy, diseased and emergency slaughtered samples, respectively. The ELISA showed the highest sensitivity for diagnosing P. multocida in apparently healthy, diseased and emergency slaughtered animals with percentages of 42%; 92.9% and 80%, respectively. The obtained results revealed that the ELISA using capsular antigen of P. multocida is a more sensitive and specific serological test for diagnosis of haemorrhagic septicaemia. PMID:26858538

  17. Genomic Comparative Study of Bovine Mastitis Escherichia coli

    PubMed Central

    Kempf, Florent; Slugocki, Cindy; Blum, Shlomo E.; Leitner, Gabriel; Germon, Pierre

    2016-01-01

    Escherichia coli, one of the main causative agents of bovine mastitis, is responsible for significant losses on dairy farms. In order to better understand the pathogenicity of E. coli mastitis, an accurate characterization of E. coli strains isolated from mastitis cases is required. By using phylogenetic analyses and whole genome comparison of 5 currently available mastitis E. coli genome sequences, we searched for genotypic traits specific for mastitis isolates. Our data confirm that there is a bias in the distribution of mastitis isolates in the different phylogenetic groups of the E. coli species, with the majority of strains belonging to phylogenetic groups A and B1. An interesting feature is that clustering of strains based on their accessory genome is very similar to that obtained using the core genome. This finding illustrates the fact that phenotypic properties of strains from different phylogroups are likely to be different. As a consequence, it is possible that different strategies could be used by mastitis isolates of different phylogroups to trigger mastitis. Our results indicate that mastitis E. coli isolates analyzed in this study carry very few of the virulence genes described in other pathogenic E. coli strains. A more detailed analysis of the presence/absence of genes involved in LPS synthesis, iron acquisition and type 6 secretion systems did not uncover specific properties of mastitis isolates. Altogether, these results indicate that mastitis E. coli isolates are rather characterized by a lack of bona fide currently described virulence genes. PMID:26809117

  18. A comparative study of feature-salience ranking techniques.

    PubMed

    Wang, W; Jones, P; Partridge, D

    2001-07-01

    We assess the relative merits of a number of techniques designed to determine the relative salience of the elements of a feature set with respect to their ability to predict a category outcome-for example, which features of a character contribute most to accurate character recognition. A number of different neural-net-based techniques have been proposed (by us and others) in addition to a standard statistical technique, and we add a technique based on inductively generated decision trees. The salience of the features that compose a proposed set is an important problem to solve efficiently and effectively, not only for neural computing technology but also in order to provide a sound basis for any attempt to design an optimal computational system. The focus of this study is the efficiency and the effectiveness with which high-salience subsets of features can be identified in the context of ill-understood and potentially noisy real-world data. Our two simple approaches, weight clamping using a neural network and feature ranking using a decision tree, generally provide a good, consistent ordering of features. In addition, linear correlation often works well. PMID:11440599

  19. Comparative cytogenetic study of three Macrolophus species (Heteroptera, Miridae)

    PubMed Central

    Jauset, Ana Maria; Edo-Tena, Eva; Castañé, Cristina; Agustí, Nuria; Alomar, Oscar; Grozeva, Snejana

    2015-01-01

    Abstract Macrolophus pygmaeus (Rambur, 1839) (Insecta, Heteroptera, Miridae) is a predator of key vegetable crop pests applied as a biocontrol agent in the Mediterranean region. Macrolophus pygmaeus and Macrolophus melanotoma (A. Costa, 1853) are cryptic species with great morphological similarity which results in their misidentification and negative consequences for the conservation of their populations on greenhouse and outdoor crops. In order to find out specific markers for their separation we studied the karyotype, male meiosis and heterochromatin composition of these species and additionally of a third species (as a reference one), Macrolophus costalis Fieber, 1858. We demonstrate here that all the three species share achiasmate male meiosis and sex chromosome pre-reduction. On the other hand, the species differ in karyotype, with 2n=28 (26+XY) in Macrolophus pygmaeus, 2n=27 (24+X1X2Y) in Macrolophus costalis, and 2n=34 (32+XY) in Macrolophus melanotoma, and heterochromatin distribution and composition. In addition, the species differ in sperm morphology: sperm cells of Macrolophus costalis are significantly longer with longer head and tail than those of Macrolophus melanotoma and Macrolophus pygmaeus, whereas sperm cells of Macrolophus melanotoma have a longer tail than those of Macrolophus pygmaeus. All these characters can be used as markers to identify the species, in particular the cryptic species Macrolophus melanotoma and Macrolophus pygmaeus. PMID:26753078

  20. [Basic symptoms in schizophrenia and alcoholism. A methodological comparative study].

    PubMed

    Mass, R; Krausz, M; Gross, J

    1995-05-01

    The results of a study on the subjective basic symptoms associated with schizophrenia and drug abuse (especially alcoholism) are presented. A total of 242 psychiatric inpatients (74 with a dual diagnosis of schizophrenia and drug consumption, 81 schizophrenics, and 87 alcoholics) were included. The three groups did not differ with regard to the general score of subjective basic symptoms measured by the Frankfurt Complaint Questionnaire (Frankfurter Beschwerde-Fragebogen, FBF). Further analyses showed that the FBF statements are only partly typical for schizophrenia; another part is connected with alcoholism. Two new scales ("FBF-S" and "FBF-A") were created from the schizophrenia-typical items and the alcoholism-typical items, respectively. In "FBF-S" schizophrenics (with and without alcoholism) had higher scores than patients suffering from alcoholism alone; in "FBF-A" alcoholics (with and without schizophrenia) reached higher scores than schizophrenic patients. Consistent correlations with independent parameters of psychosis and alcoholism confirm the validity of "FBF-S" and "FBF-A". It is concluded that the FBF's capacity to discriminate different diagnoses can be improved and that the model of basic disturbances must be re-evaluated. PMID:7609813

  1. Reduced bases for nonlinear structural dynamic systems: A comparative study

    NASA Astrophysics Data System (ADS)

    Lülf, Fritz Adrian; Tran, Duc-Minh; Ohayon, Roger

    2013-07-01

    The presented work provides an overview of some commonly used approaches for generating reduced bases for discrete nonlinear dynamic systems. It investigates the performance and the robustness of these bases if they are applied in a reduction-by-projection procedure on different test cases. The bases are created from the Linear Normal Modes, the Ritz-vectors, the Proper and the Smooth Orthogonal Decomposition method, the A Priori Reduction, the Centroidal Voronoi Tessellation and the Local Equivalent Linear Stiffness Method. Second-Order Terms and an Enhanced Proper Orthogonal Decomposition formulation are included as variants. The test cases are small dimensional, locally or entirely nonlinear system subjected to a harmonic or an impulse force excitation. The double objective of this numerical study is, first, to determine which bases are most adequate for a given combination of nonlinearity and excitation and, second, to which extend the bases exhibit an inherent robustness if the parameterisation of the excitation is changed. A specific multicriteria decision analysis score is developed to assess the bases' performance. As a major result, a strong dependence of the performance of the bases on the type of excitation is established and thus some bases become more adequate for a certain situation than others. Also a lack of robustness for all considered bases can be observed. This situation improves in most cases if the basis is generated with the most critical values of the parameter.

  2. Comparative pharmacokinetic study of chewable and conventional carbamazepine in children.

    PubMed

    Cornaggia, C; Gianetti, S; Battino, D; Granata, T; Romeo, A; Viani, F; Limido, G

    1993-01-01

    Fifteen children (7 boys and 8 girls) with generalized tonic-clonic seizures (GTCS) and partial seizures with elementary or complex symptomatology, treated with carbamazepine (CBZ) alone (n = 7) or in combination with either phenobarbital (PB, n = 6) or clobazam (CLB, n = 2) given for at least 3 months at stable individualized doses and regimens, entered an open, within-patient, change-over study of consecutive periods, each lasting 2 weeks. During period 1, conventional CBZ was given; during period 2, a chewable CBZ formulation was substituted for conventional CBZ and given at the same total daily dosage with the same schedule as in period 1. Blood samples for measuring plasma concentration of both total CBZ and CBZ-10,11 epoxide (CBZ-E) were taken on the last day of each period. No significant difference between the two periods was noted in the mean +/- SD of Cmax, Css mean, and area under the curve (AUC) of total CBZ and CBZ-E. The two different CBZ formulations, administered at the same total daily dosage, can be considered bioequivalent. PMID:8422850

  3. Masked auditory thresholds in sciaenid fishes: A comparative study

    NASA Astrophysics Data System (ADS)

    Ramcharitar, John; Popper, Arthur N.

    2004-09-01

    Western Atlantic sciaenids comprise a taxonomically diverse teleost family with significant variations in the relationship between the swim bladder and the otic capsule. In this study, the auditory brainstem response (ABR) was used to test the hypothesis that fishes with different peripheral auditory structures (black drum, Pogonias chromis and Atlantic croaker, Micropogonias undulatus) show differences in frequency selectivity. In a black drum the swim bladder is relatively distant from the otic capsule while the swim bladder in Atlantic croaker possesses anteriorly-directed diverticulas that terminate relatively near the otic capsule. Signals were pure tones in the frequency range, 100 Hz to 1.5 kHz, and thresholds were determined both with and without the presence of simultaneous white noise at two intensity levels (124 dB and 136 dB, re: 1 μPa). At the 124 dB level of white noise background, both the black drum and Atlantic croaker showed similar changes in auditory sensitivity. However, in the presence of the 136 dB white noise masker, black drum showed significantly greater shifts in auditory thresholds between 300 and 600 Hz. The results indicate that the two species differ in frequency selectivity since the Atlantic croaker was less susceptible to auditory threshold shifts, particularly at the higher level of masking. This difference may be linked to peripheral auditory mechanisms.

  4. Thiolate alkylation in tripod zinc complexes: a comparative kinetic study.

    PubMed

    Rombach, Michael; Seebacher, Jan; Ji, Mian; Zhang, Guofang; He, Guosen; Ibrahim, Mohamed M; Benkmil, Boumahdi; Vahrenkamp, Heinrich

    2006-05-29

    The biologically relevant alkylations of the thiolate ligands in tripod zinc thiolates by methyl iodide were studied kinetically. Five tripod ligands of the pyrazolyl/thioimidazolyl borate type were employed, offering N3, N2S, NS2, and S3 donor sets. For each of them, the ethyl-, benzyl-, phenyl-, and p-nitrophenylthiolate zinc complexes were investigated, yielding a total of 20 second-order rate constants. The comparison of these rate constants shows three effects: (1) the electronic effect among the thiolates, i.e., the ethanethiolates react about 3 orders of magnitude faster than the p-nitrophenylthiolates; (2) the steric effect among the pyrazolylborates, i.e., the phenyl-substituted ones react about 2 orders of magnitude faster than the tert-butyl-substituted ones; and (3) the strong acceleration by the sulfur donors in the tripods, reaching 4 orders of magnitude between the reaction times of the (N3)Zn-SR and (S3)Zn-SR complexes. PMID:16711708

  5. Comparative theoretical studies of energetic azo s-triazines.

    PubMed

    Wang, Fang; Du, Hong-chen; Zhang, Jian-ying; Gong, Xue-dong

    2011-10-27

    In this work, the properties of the synthesized high-nitrogen compounds 4,4',6,6'-tetra(azido)azo-1,3,5-triazine (TAAT) and 4,4',6,6'-tetra(azido)hydrazo-1,3,5-triazine (TAHT), and a set of designed bridged triazines with similar bridges were studied theoretically to facilitate further developments for the molecules of interests. The gas-phase heats of formation were predicted based on the isodesmic reactions by using the DFT-B3LYP/AUG-cc-PVDZ method. The estimates of the condensed-phase heats of formation and heats of sublimation were estimated in the framework of the Politzer approach. Calculation results show that the method gives a good estimation for enthalpies, in comparison with available experimental data for TAAT and TAHT. The crystal density has been computed using molecular packing calculations. The calculated detonation velocities and detonation pressures indicate that -NF(2), -NO(2), -N═N-, and -N═N(O)- groups are effective structural units for improving the detonation performance of the bridged triazines. The synthesized TAAT and TAHT are not preferred energetic materials due to their inferior detonation performance. The p→π conjugation effect between the triazine rings and bridges makes the molecule stable as a whole. The electrostatic behavior of the bridged triazines is characterized by an anomalous surface potential imbalance when incorporating the strongly electron-withdrawing -NF(2) and -NO(2) groups into the molecule. An analysis of the bond dissociation energies shows that all these derivatives have good thermal stability over RDX and HMX, and the -NH-NH- bridge is more helpful for improving the stability than -N═N(O)- and -N═N- bridges. Considering the detonation performance and thermal stability, three bridged triazines may be considered as the potential candidates of high-energy density materials (HEDMs). PMID:21910431

  6. Effects of acute cooling on fish electroretinogram: a comparative study.

    PubMed

    Gačić, Zoran; Milošević, Milena; Mićković, Branislav; Nikčević, Miroslav; Damjanović, Ilija

    2015-06-01

    Temperature dependence of electroretinogram (ERG) was investigated in 3 fish species occupying different habitats--dogfish shark (Scyliorhinus canicula), Prussian carp (Carassius gibelio) and European eel (Anguilla anguilla). Acute cooling of the shark isolated eyecup from 23°C down to 6°C induced suppression of the electroretinographic b-wave--a complete degradation of this component was observed at 6°C. On the other hand, photoreceptor component of the ERG, the negative late receptor potential was not affected by cooling. The fact that the suppression of the dogfish shark b-wave at low temperatures was as a rule irreversible testifies about breakdown of neural retinal function at cold temperature extremes. Although in vivo experiments on immobilized Prussian carps have never resulted in complete deterioration of the b-wave at low temperatures, significant suppression of this ERG component by cooling was detected. Suppressing the effect of low temperatures on Prussian carp ERG might be due to the fact that C. gibelio, as well as other cyprinids, can be characterized as a warmwater species preferring temperatures well above cold extremes. The ERG of the eel, the third examined species, exhibited the strongest resistance to extremely low temperatures. During acute cooling of in situ eyecup preparations of migrating silver eels from 30°C down to 2°C the form of ERG became wider, but the amplitude of the b-wave only slightly decreased. High tolerance of eel b-wave to cold extremes shown in our study complies with ecological data confirming eurythermia in migrating silver eels remarkably adapted to cold-water environment as well. PMID:25759261

  7. Social Impact of Solar Eclipse in Indonesia: A Comparative Study

    NASA Astrophysics Data System (ADS)

    Mumpuni, Emanuel S.; Hidayat, Bambang

    2012-09-01

    The social impact and public comprehension of the natural phenomenon varies depending on how a particular cultural background perceives the phenomenon and how the interaction between general public and the authoritative bodies has persisted. While astronomers and scientists have taken for granted that solar eclipse is a natural phenomenon and subjected it to various scientific studies, large percentages of the population have been left uninformed scientifically and have responded to the phenomena quite differently. The technical and scientific aspects of the earliest expedition, to Padang (Sumatra) in 1901, have recently been discussed at length.Two major solar eclipses, namely the 1926 and 1929, offered many scientific outputs as well as results on observations of societies: anthropology, demography, and culinary habits of the local inhabitants. Those days, science was the preserve of a few selected. To a certain degree, many old perceptions of on natural phenomena, with their ruling deities still lingered on. The purpose of this paper is to show the changing views of the endogenous population in particular after the government's massive efforts to enlighten the people and to empower the younger generations in comprehending natural phenomena. The great efforts of the Government of Indonesia's Institute of Sciences (LIPI) related to the June 1983 solar eclipse produced a dramatic change in the sense of appreciation of solar eclipse as a natural phenomenon in consequence of relative motions of the Sun, Moon and the Earth. It took however another five years, till the time of the great eclipse in 1988, to a full fruition in which younger generations as well as older ones abandoned almost completely the old views and embarked on the understanding the value of solar eclipse for science.

  8. Accuracy of ambulatory blood pressure determination: a comparative study.

    PubMed

    Barthélémy, J C; Geyssant, A; Auboyer, C; Antoniadis, A; Berruyer, J; Lacour, J R

    1991-09-01

    This study was designed to discriminate, according to their accuracy, between three ambulatory pressurometers (Diasys 200R, Novacor; P IV, Del Mar Avionics; SpaceLab 90202, SpaceLab). The evaluation was performed against invasive arterial reference measurements. Accuracy was assessed by calculating the error on pressure (EOP) as the difference between invasive and non-invasive measurement of arterial blood pressure. For the systolic values, accuracy (mean of EOP differences) and uncertainty (SD of these differences) were -0.9 +/- 9.7, -4.3 +/- 10.1 and -16.7 +/- 10.1 mmHg for, respectively, Diasys, PIV and SpaceLab. For diastolic values, they were, respectively, 5.9 +/- 6.7, 6.8 +/- 8.5 and 9.1 +/- 6.6 mmHg. EOP was then separated in two different types of errors: (i) the error of dispersion appreciated by the index of homogeneity calculated by a Lehmann analysis and leading to a statistical classification (ii) the error due to the drift of EOP with the reference value, this last error being easier to correct. Two different behaviours were observed for the EOP: (i) the drift of EOP of systolic values was significantly larger for the oscillometric (SpaceLab) than for the auscultatory (Diasys and P IV) method, with no difference between Diasys and P IV (ii) the homogeneity index was not statistically different among these three devices. These data suggest that, in case the correction of the drift of EOP is carried out, there is no statistical significant difference in accuracy between these three pressurometers. However, in our experimental conditions, the two ambulatory pressurometers recording the Korotkoff sounds have a better accuracy than the one using the oscillometric approach. PMID:1947731

  9. A Comparative Study of Leptospirosis and Dengue in Thai Children

    PubMed Central

    Libraty, Daniel H.; Myint, Khin S. A.; Murray, Clinton K.; Gibbons, Robert V.; Mammen, Mammen P.; Endy, Timothy P.; Li, Wenjun; Vaughn, David W.; Nisalak, Ananda; Kalayanarooj, Siripen; Hospenthal, Duane R.; Green, Sharone; Rothman, Alan L.; Ennis, Francis A.

    2007-01-01

    Background Leptospirosis is an emerging zoonosis that is often under-recognized in children and commonly confused with dengue in tropical settings. An enhanced ability to distinguish leptospirosis from dengue in children would guide clinicians and public health personnel in the appropriate use of limited healthcare resources. Methodology/Principal Findings We conducted a prospective, hospital-based, study of children with acute febrile illnesses and dengue in Thailand. Among the children without dengue, we identified those with leptospirosis using anti-leptospira IgM and microscopic agglutination titers in paired acute and convalescent blood samples. We then performed a case-control comparison of symptoms, signs, and clinical laboratory values between children with leptospirosis and dengue. In a semi-rural region of Thailand, leptospirosis accounted for 19% of the non-dengue acute febrile illnesses among children presenting during the rainy season. None of the children with leptospirosis were correctly diagnosed at the time of hospital discharge, and one third (33%) were erroneously diagnosed as dengue or scrub typhus. A predictive model to distinguish pediatric leptospirosis from dengue was generated using three variables: the absolute neutrophil count, plasma albumin, and aspartate aminotransferase levels in the first 72 hours of illness. Conclusions/Significance Unrecognized leptospirosis can be a significant cause of “dengue-like” febrile illness in children. Increased awareness of pediatric leptospirosis, and an enhanced ability to discriminate between leptospirosis and dengue early in illness, will help guide the appropriate use of healthcare resources in often resource-limited settings. PMID:18160980

  10. Absorbable scaphoid screw development: a comparative study on biomechanics

    PubMed Central

    Wang, Yi; Song, Muguo; Xu, Yongqing; He, Xiaoqing; Zhu, YueLiang

    2016-01-01

    Background The scaphoid is critical for maintaining the stability and movement of the wrist joints. This study aimed to develop a new internal fixator absorbable scaphoid screw (ASS) for fixation of the scaphoid waist after fracture and to test the biomechanical characteristics of ASS. Materials and methods An ASS was prepared using polylactic acids and designed based on scaphoid measurements and anatomic features. Twenty fractured scaphoid waist specimens were randomly divided into experimental and control groups (n=10/group). Reduction and internal fixation of the scaphoid were achieved with either Kirschner wires (K-wires) or ASS. A moving target simulator was used to test palmar flexion and dorsal extension, with the range of testing (waist movement) set from 5° of palmar flexion to 25° of dorsal extension. Flexion and extension were repeated 2,000 times for each specimen. Fracture gap displacements were measured with a computerized tomography scanning. Scaphoid tensile and bending strengths were measured by using a hydraulic pressure biomechanical system. Results Prior to biomechanical fatigue testing, fracture gap displacements were 0.16±0.02 mm and 0.22±0.02 mm in the ASS and K-wire groups, respectively. After fatigue testing, fracture gap displacements in the ASS and the K-wire groups were 0.21±0.03 mm and 1.52±0.07 mm, respectively. The tensile strengths for the ASS and K-wire groups were 0.95±0.02 MPa and 0.63±0.02 MPa, respectively. Conclusion Fixation using an ASS provided sufficient mechanical support for the scaphoid after fracture. PMID:27217756

  11. A comparative study of atmospheric corrosion in the Caribbean area

    SciTech Connect

    Maldonado, L.; Castro, P.; Echeverria, M.

    1995-10-01

    Atmospheric corrosion is a phenomenon of such a magnitude that has been cause of study in several countries for decades. Nevertheless, in Mexico, it became of recent interest due to new economic factors that have involved the Peninsula of Yucatan too. The Yucatan Peninsula is limited to the North and West by the Gulf of Mexico and to the East by the Caribbean Sea. This is a non industrialized region so that in the past very little importance was given to the atmospheric corrosion damage or to the quantification of the high corrosion rates, empirically observed. However, in recent times increased tourism, industrial growth and petroleum extraction have exhibited the need for a better understanding of the atmospheric corrosion processes, as well as a realistic correlation to parameters such as time-of-wetness, levels of pollution by airborne salinity, atmospheric S0{sub 2} and corrosivity categories for the metals. To evaluate these parameters, five tests sites were selected following ISO recommendations. Three sites are marines atmospheres, one urban and one rural. Corrosion rates for commercial laminated Cu and carbon steel, as well as deposition rates of pollutants, were determined after one year exposure in the test sites. Applying the standard practice ISO 9223 a categorization of the corrosivity and of the level of pollutants was carried out. The marine environments were classified as of atmospheric corrosivity C{sub 5}, while the urban and the rural could be classified as C{sub 3}, respectively. The pollution values showed that the exposure sites were essentially contaminated with chloride with classification S{sub 1} for the rural site and S{sub 3} for the marine atmosphere.

  12. Habitability potential of icy moons: a comparative study

    NASA Astrophysics Data System (ADS)

    Solomonidou, Anezina; Coustenis, Athena; Encrenaz, Thérèse; Sohl, Frank; Hussmann, Hauke; Bampasidis, Georgios; Wagner, Frank; Raulin, François; Schulze-Makuch, Dirk; Lopes, Rosaly

    2014-05-01

    environments to look for biomarkers. Currently, for Titan and Enceladus, geophysical models try to explain the possible existence of an oceanic layer that decouples the mantle from the icy crust. If the silicate mantles of Eu-ropa and Ganymede and the liquid sources of Titan and Enceladus are geologically active as on Earth, giving rise to the equivalent of hydrothermal systems, the simultaneous presence of water, geodynamic interactions, chemical en-ergy sources and a diversity of key chemical elements may fulfill the basic conditions for habitability. Titan has been suggested to be a possible cryovolcanic world due to the presence of local complex volcanic-like geomorphol-ogy and the indications of surface albedo changes with time [7,8]. Such dynamic activity that would most probably include tidal heating, possible internal convection, and ice tectonics, is believed to be a pre-requisite of a habitable planetary body as it allows the recycling of minerals and potential nutrients and provides localized energy sources. In a recent study by Sohl et al. [2013], we have shown that tidal forces are a constant and significant source of inter-nal deformation on Titan and the interior liquid water ocean can be relatively warm for reasonable amounts of am-monia concentrations, thus completing the set of parameters needed for a truly habitable planetary body. Such habi-tability indications from bodies at distances of 10 AU, are essential discoveries brought to us by space exploration and which have recently revolutionized our perception of habitability in the solar system. In the solar system's neighborhood, such potential habitats can only be investigated with appropriate designed space missions, like JUICE-Laplace (JUpiter ICy moon Explorer) for Ganymede and Europa [9]. JUICE is an ESA mission to Jupiter and its icy moons, recently selected to launch in 2022. References: [1] Coustenis, A., Encrenaz, Th., in "Life Beyond Earth : the search for habitable worlds in the Universe

  13. Adaptation of Diaphyseal Structure With Aging and Increased Mechanical Usage in the Adult Rat: A Histomorphometrical and Biomechanical Study

    NASA Technical Reports Server (NTRS)

    Jee, Webster S. S.; Li, Xiao Jian; Schaffler, Mitchell B.

    1991-01-01

    The experimental increase in mechanical usage or overloading of the left hindlimb was produced by immobilization of the contralateral hindlimb. The right hindlimb was placed in a flexed position against the body and was immobilized using an elastic bandage. Some control animals were sacrificed initially at time zero and increased mechanical usage and age-matched control animals were sacrificed after 2, 10, 18, and 26 weeks of treatment. All animals received double bone fluorochrome labeling prior to sacrifice. Cortical bone histomorphometry and cross-sectional moments of inertia were determined. Marrow cavity enlargement and total cross-sectional area expansion represented the age-related cortical bone changes. Increased mechanical usage enhanced periosteal bone modeling in the formation mode and dampened endocortical bone remodeling and bone modeling in the resorption mode (resorption drift) to create a slight positive bone balance. These observations are in general agreement with Frost's postulate for mechanical effects on bone modeling and remodeling. The maximum moment of inertia did not change significantly in either control or overloaded tibial shafts. The minimum and polar moment of inertias in overloaded bones increases over those of controls at 18 and 26 weeks of the experiment.

  14. Adaptation of Diaphyseal Structure with Aging and Increased Mechanical Usage in the Adult Rat: A Histomorphometrical and Biomechanical Study

    NASA Technical Reports Server (NTRS)

    Jee, Webster S. S.; Li, Xiao Jian; Schaffler, Mitchell B.

    1991-01-01

    The experimental increase in mechanical usage or overloading of the left hindlimb was produced by immobilization of the contralateral hindlimb. The right hindlimb was placed in a flexed position against the body and was immobilized using an elastic bandage. Some control animals were sacrificed initially at time zero and increased mechanical usage and age-matched control animals were sacrificed after 2, 10, 18, and 26 weeks of treatment. All animals received double bone fluorochrome labeling prior to sacrifice. Cortical bone histomorphometry and cross-sectional moments of inertia were determined. Marrow cavity enlargement and total cross-sectional area expansion represented the age-related cortical bone changes. Increased mechanical usage enhanced periosteal bone modeling in the formation mode and dampened endocortical bone remodeling and bone modeling in the resorption mode (resorption drift) to create a slight positive bone balance. These observations are in general agreement with Frost's postulate for mechanical effects on bone modeling and remodeling. The maximum moment of inertia did not change significantly in either control or overloaded tibial shafts. The minimum and polar moment of inertias in overloaded bones increases over those of controls at 18 and 26 weeks of the experiment.

  15. Comparative Study of Population Growth and Agricultural Change: C - Case Study of India. Asian Population Studies Series No. 23.

    ERIC Educational Resources Information Center

    United Nations Economic and Social Commission for Asia and the Pacific, Bangkok (Thailand).

    This report, the third in a series of five reports of the Comparative Study of Population Growth and Agricultural Change, describes a study of the two states of India (Punjaband and Orissa) which attempted to clarify the relationship between population pressure and agricultural change through a time series analysis. This study: (1) outlines trends…

  16. Alveolar bone regeneration for immediate implant placement using an injectable bone substitute: an experimental study in dogs

    PubMed Central

    Boix, Damien; Gauthier, Olivier; Guicheux, Jérôme; Pilet, Paul; Weiss, Pierre; Grimandi, Gaël; Daculsi, Guy

    2004-01-01

    Background The aim of the present study was to assess the efficacy of a ready-to-use injectable bone substitute for bone regeneration around dental implants placed into fresh extraction sockets. Methods Third and fourth mandibular premolars were extracted from 3 Beagle dogs and the interradicular septa were surgically reduced to induce a mesial bone defect. Thereafter, immediate placements of titanium implants were performed. On the left side of the jaw, mesial bone defects were filled with an injectable bone substitute (IBS), obtained by combining a polymer and a biphasic calcium phosphate ceramic. As a control, the right defects were left unfilled. After 3 months of healing, specimens were prepared for histological and histomorphometric evaluations. Results No post surgical complication was observed during the healing period. In all experimental conditions, histological observations revealed a lamellar bone formation in contact with the implant. Histomorphometric analysis showed that IBS triggers a significant (p<0.05) increase in term of thread numbers in contact with bone (TN), bone-to-implant contact (BIC) and peri-implant bone density (PBD), of about 8.6%, 11.0% and 14.7%, respectively. In addition, no significant difference was observed when TN, BIC and PBD in filled defects were compared to no-defect sites. Conclusion It is concluded that an injectable bone substitute composed of a polymeric carrier and calcium phosphate significantly increase bone regeneration around immediate implants. PMID:15212348

  17. Surface characterization and in vivo evaluation of laser sintered and machined implants followed by resorbable-blasting media process: A study in sheep

    PubMed Central

    Bowers, Michelle; Yoo, Daniel; Marin, Charles; Gil, Luiz; Shabaka, Nour; Goldstein, Matt; Janal, Malvin; Tovar, Nick; Bonfante, Estevam; Coelho, Paulo

    2016-01-01

    Background This study aimed to compare the histomorphometric and histological bone response to laser-sintered implants followed by resorbable-blasting media (RBM) process relative to standard machined/RBM surface treated implants. Material and Methods Six male sheep (n=6) received 2 Ti-6Al-4V implants (1 per surface) in each side of the mandible for 6 weeks in vivo. The histomorphometric parameters bone-implant contact (BIC) and bone area fraction occupancy (BAFO) were evaluated. Results Optical interferometry revealed higher Sa and Sq values for the laser-sintered/RBM surface in relation to standard/RBM implants. No significant differences in BIC were observed between the two groups (p>0.2), but significantly higher BAFO was observed for standard/RBM implants (p<0.01). Conclusions The present study demonstrated that both surfaces were biocompatible and osseoconductive, and the combination of laser sintering and RBM has no advantage over the standard machined implants with subsequent RBM. Key words:Dental implants, osseointegration, resorbable- blasting media, sheep, in vivo. PMID:26827064

  18. A Comparative Study of Biodegradation of Nickel and Chromium from Space Maintainers: An in vitro Study

    PubMed Central

    Anand, Ashish; Sharma, Arun; Kumar, Piush; Sachdeva, Shobhit; Sachdev, Vinod

    2015-01-01

    ABSTRACT Objective: The aim of the study was to compare and evaluate the in vitro biodegradation of nickel and chromium from space maintainers, made of three different companies, i.e (Dantaurum, Rocky mountain and Dtech) in artificial saliva. Materials and methods: The study comprised of 30 space maintainers out of which 10 were fabricated using Dantaurum, 10 using Rocky mountain and 10 using Dtech band materials. Stainless steel wire (Dantaurum, Rocky mountain and Konark) was used for making loops and Leone solder and flux was used for soldering. Each group was further divided into four subgroups containing 1, 2, 3 and 4 space maintainers respectively. The space maintainers in each subgroup were placed in separate glass beakers containing 100 ml of artificial saliva at 37°C for 4 weeks. Salivary samples from each beaker was analyzed for nickel and chromium ions separately on days 1, 7, 14, 21 and 28 days using inductively coupled plasma-optical emission spectrophotometer. Results: Total release of nickel and chromium from all band and loop space maintainers ranged from 0.020 to 1.524 ppm and 0.002 to 0.289 ppm respectively. The release of nickel and chromium between the groups and within the groups was not significant (p < 0.5). Conclusion: There was no substantial release of nickel and chromium from space maintainers made of Dantaurum, Rocky mountain and Dtech which could cause any toxicity. How to cite this article: Anand A, Sharma A, Kumar P, Sandhu M, Sachdeva S, Sachdev V. A Comparative Study of Biodegradation of Nickel and Chromium from Space Maintainers: An in vitro Study. Int J Clin Pediatr Dent 2015; 8(1):37-41. PMID:26124579

  19. Comparative study between two techniques for alveolar bone loss assessment: A pilot study

    PubMed Central

    Lira-Júnior, Ronaldo; Freires, Irlan de Almeida; de Oliveira, Isabelle LinsMacêdo; da Silva, Ennyo Sobral Crispim; da Silva, SeverinoCelestino; de Brito, Roberto Lira

    2013-01-01

    Objective: To conduct a comparative study between two techniques for assessment of alveolar bone loss. Materials and Methods: Absolute and relative techniques were evaluated. The sample consisted of 16 radiographs supposed to meet a single criterion: The reference points applied (Cementum-enamel junction (CEJ) alveolar bone crest and root apex) should be visible. Bone height was measured in the selected radiographs as the percentage of root length through both techniques. Data were submitted to the Statistical Package for Social Science software. Results obtained by both methods were converted into bone loss index values and then categorized. Sensitivity and specificity of the relative technique, compared to the absolute technique, were calculated. Wilcoxon test and the Bland and Altman's method were employed for comparisons. Significance level was set at 5%. Results: For the absolute and relative techniques, means of bone loss index were respectively of 4.81 (±2.25) and 4.75 (±1.80). Bone loss index ≥6 (alveolar bone loss ≥50%) was found in 5 (31.2%) teeth, in the absolute technique, and in 4 (25%) teeth, according to the relative technique. There was no statistically significant difference between both methods (P>0.05). According to the Bland and Altman's method, it was verified a bias of 0.06, and limits of upper and lower agreement of, respectively, 1.58 and –1.45. Sensitivity of 0.8 and specificity of 1 were found for the relative technique compared to the absolute one. Conclusion: There was no significant difference between the techniques evaluated, and the relative technique was found to be reliable for measuring alveolar bone loss. PMID:23633780

  20. ICMSF methods studies. XII. Comparative study for the enumeration of Clostridium perfringens in feces.

    PubMed

    Hauschild, A H; Desmarchelier, P; Gilbert, R J; Harmon, S M; Vahlefeld, R

    1979-09-01

    As the second phase of an international comparative study for the enumeration of Clostridium perfringens, four methods were compared for "total" and spore counts of C. perfringens in fecal specimens: the SFP (Shahidi-Ferguson perfringens) agar (A), TSC (tryptose-sulfite-cycloserine) agar (B), SC (sulfite-cycloserine) agar (C), and neomycin blood agar (D) methods. In both the total and spore count procedures, the confirmed C. perfringens counts in method D were lower than in methods A, B, and C. Little differences among methods were found in the percentages of presumptive colonies confirmed as C. perfringens. The nonspecific counts in methods A and D were generally greater than in B and C, but nonspecific microorganisms did not interfere in the enumeration of C. perfringens spores by any of the four methods. In overall performance, methods B and C were superior to A and D. The mean C. perfringens spore count was only 0.17 log lower than the mean total count. Spore counts alone are, therefore, adequate in investigations of C. perfringens outbreaks. PMID:232005