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Sample records for nauplii biometry characteristics

  1. Prevalence of Corneal Astigmatism and Anterior Segmental Biometry Characteristics Before Surgery in Chinese Congenital Cataract Patients

    PubMed Central

    Lin, Duoru; Chen, Jingjing; Liu, Zhenzhen; Wu, Xiaohang; Long, Erping; Luo, Lixia; Lin, Zhuoling; Li, Xiaoyan; Zhang, Li; Chen, Hui; Liu, Jinchao; Chen, Weirong; Lin, Haotian; Liu, Yizhi

    2016-01-01

    The prevalence and the distribution characteristics of corneal astigmatism (CA) and anterior segment biometry before surgery in Chinese congenital cataract (CC) patients are not completely understood. This study involved 400 CC patients from the Zhongshan Ophthalmic Center enrolled from February 2011 to August 2015. Data on CA, keratometry, central corneal thickness (CCT) and anterior chamber depth (ACD) were measured by the Pentacam Scheimpflug System. The mean age of patients was 54.27 months, and the ratio of boys to girls was 1.53:1. The mean CA was 2.03 diopters (D), and 39.25% of subjects had CA values ≥2 D. The most frequent (71.8%) diagnosis was with-the-rule astigmatism. Oblique astigmatism was present in 16.2% of cases, and 12% of cases had against-the-rule astigmatism. The mean keratometry measurement of cataractous eyes in bilateral patients was significantly larger than that in unilateral patients. Girls had a larger mean keratometry but a thinner CCT than did boys. The CA, CCT, and ACD of cataractous eyes were significantly larger than those of non-cataractous eyes in unilateral patients. The CA, mean keratometry, CCT, and ACD in CC patients varied with age, gender, and laterality. Fully understanding these characteristics may help inform guidelines and treatment decisions in CC patients. PMID:26912400

  2. Prevalence of Corneal Astigmatism and Anterior Segmental Biometry Characteristics Before Surgery in Chinese Congenital Cataract Patients.

    PubMed

    Lin, Duoru; Chen, Jingjing; Liu, Zhenzhen; Wu, Xiaohang; Long, Erping; Luo, Lixia; Lin, Zhuoling; Li, Xiaoyan; Zhang, Li; Chen, Hui; Liu, Jinchao; Chen, Weirong; Lin, Haotian; Liu, Yizhi

    2016-02-25

    The prevalence and the distribution characteristics of corneal astigmatism (CA) and anterior segment biometry before surgery in Chinese congenital cataract (CC) patients are not completely understood. This study involved 400 CC patients from the Zhongshan Ophthalmic Center enrolled from February 2011 to August 2015. Data on CA, keratometry, central corneal thickness (CCT) and anterior chamber depth (ACD) were measured by the Pentacam Scheimpflug System. The mean age of patients was 54.27 months, and the ratio of boys to girls was 1.53:1. The mean CA was 2.03 diopters (D), and 39.25% of subjects had CA values ≥2 D. The most frequent (71.8%) diagnosis was with-the-rule astigmatism. Oblique astigmatism was present in 16.2% of cases, and 12% of cases had against-the-rule astigmatism. The mean keratometry measurement of cataractous eyes in bilateral patients was significantly larger than that in unilateral patients. Girls had a larger mean keratometry but a thinner CCT than did boys. The CA, CCT, and ACD of cataractous eyes were significantly larger than those of non-cataractous eyes in unilateral patients. The CA, mean keratometry, CCT, and ACD in CC patients varied with age, gender, and laterality. Fully understanding these characteristics may help inform guidelines and treatment decisions in CC patients.

  3. Choreographed swimming of copepod nauplii

    PubMed Central

    Takagi, Daisuke; Hartline, Daniel K.

    2015-01-01

    Small metazoan paddlers, such as crustacean larvae (nauplii), are abundant, ecologically important and active swimmers, which depend on exploiting viscous forces for locomotion. The physics of micropaddling at low Reynolds number was investigated using a model of swimming based on slender-body theory for Stokes flow. Locomotion of nauplii of the copepod Bestiolina similis was quantified from high-speed video images to obtain precise measurements of appendage movements and the resulting displacement of the body. The kinematic and morphological data served as inputs to the model, which predicted the displacement in good agreement with observations. The results of interest did not depend sensitively on the parameters within the error of measurement. Model tests revealed that the commonly attributed mechanism of ‘feathering’ appendages during return strokes accounts for only part of the displacement. As important for effective paddling at low Reynolds number is the ability to generate a metachronal sequence of power strokes in combination with synchronous return strokes of appendages. The effect of feathering together with a synchronous return stroke is greater than the sum of each factor individually. The model serves as a foundation for future exploration of micropaddlers swimming at intermediate Reynolds number where both viscous and inertial forces are important. PMID:26490629

  4. Biometry | Division of Cancer Prevention

    Cancer.gov

    [[{"fid":"66","view_mode":"default","fields":{"format":"default","field_file_image_alt_text[und][0][value]":"Biometry Research Group Homepage Logo","field_file_image_title_text[und][0][value]":"Biometry Research Group Homepage Logo","field_folder[und]":"15"},"type":"media","attributes":{"alt":"Biometry Research Group Homepage Logo","title":"Biometry Research Group Homepage Logo","height":"266","width":"400","style":"height: 259px; width: 400px;","class":"image-style-none media-element file-de | Consults, conducts and supports independent and collaborative research and data analysis.

  5. Physiological characteristics and stress resistance of great sturgeon (Huso huso) juveniles fed with vitamins C, E, and HUFA-enriched Artemia urmiana nauplii.

    PubMed

    Jalali, Mohammad Ali; Hosseini, Seyed Abbas; Imanpour, Mohammad Reza

    2010-09-01

    This study was carried out to examine the effect of Artemia urmiana nauplii enriched with HUFA, and vitamins C and E on stress tolerance, hematocrit, and biochemical parameters of great sturgeon, Huso huso juveniles. Cod liver oil (EPA 18% and DHA 12%), ascorbyl-6-palmitate and alpha-tocopherol acetate were used as lipid, and vitamin C and E sources, respectively. Beluga juveniles at the stage of first feeding (69.7 +/- 5.9 mg body weight) were randomly divided into five treatments and three tanks were assigned to each diet. All fish groups were fed non-enriched Artemia for the initial 5 days and then fed enriched Artemia for 7 days. Juveniles were fed with Artemia enriched with HUFA + 20% vitamin C (C group); HUFA + 20% vitamin E-enriched Artemia nauplii (E group); HUFA + 20% vitamin C + 20% vitamin E (C and E group); HUFA without vitamins (HUFA) and non-enriched Artemia (control). After the period of enrichment, Juveniles were fed with Daphnia sp. from the 13th to the 40th day. At day 40, the fish were transferred directly from fresh water (0.5 ppt) to brackish water (6 ppt for 4 days and 12 ppt for 2 days) and warm water (from 27 to 33 degrees C) to evaluate juvenile resistance to salinity and thermal shocks. Moreover, all treatments were separately exposed to freshwater in tanks with the same capacity as used for osmotic and thermal tests (as fresh water control). The addition of vitamins C, E, and C + E to HUFA significantly increased fish resistance to 12 ppt salinity and temperature stress tests, whereas survival was not significantly different among challenges at 6 ppt. There was no significant difference in the hematocrit index under stress conditions. Enrichment had significant influence on plasma Na(+) level in the C group on the 4th day at 6 ppt. Na(+) and Ca(2+) concentrations in C, E, and C and E groups on the 1st day at 12 ppt, and Ca(2+) level in E group on the 2nd day at 12 ppt were lower than the other groups. The glucose level in the C and C and

  6. [Ocular biometry using Orbscan].

    PubMed

    Touzeau, O; Allouch, C; Borderie, V; Laroche, L

    2005-06-01

    Orbscan is a recent optical device that combines the Placido disk of the videokeratoscope and a scanning slit. The scanning slit measures the elevation of both the corneal surface (anterior and posterior) and the anterior iris-lens surface. Biometric measures of the anterior segment such as corneal thickness, anterior chamber depth, corneal diameter, and iridocorneal angle are obtained using spatial coordinates of various ocular surfaces. Orbscan is not only a corneal topograph but a versatile device capable of measuring the biometry of the anterior segment of the eye.

  7. When May Feeding Rates Cover Metabolic Expenses of Planktonic Nauplii?

    NASA Astrophysics Data System (ADS)

    Paffenhofer, G. A.; Koester, M.

    2016-02-01

    Among planktonic copepods, which are the most abundant metazoa on our planet, nauplii represent a greater percentage in number than all later stages. While most nauplii do not possess the ability to perceive predators as well as later stages do, they have the additional disadvantage of higher metabolic needs (energy expenditure per unit body weight) than their older brethren. To determine metabolic expenditures of 3 species of calanoid nauplii (Eucalanus pileatus, Paracalanus quasimodo, Temora turbinata) we quantified their oxygen consumption and feeding rates simultaneously at different environmental food levels. As shown previously for adult females of planktonic copepods motion governs oxygen consumption and therefore the metabolic needs. Also, the type of motion matters. Because of major energy expenditures for motion nauplii of some calanoids can barely persist at low environmental phytoplankton levels. Therefore, we ask the question: Will temporary food shortages have similar effects as predation on the survival of calanoid nauplii? Our results should broaden our understanding on the effect of food limitation on the survival of planktonic nauplii.

  8. Prey Detection and Prey Capture in Copepod Nauplii

    PubMed Central

    Bruno, Eleonora; Andersen Borg, Christian Marc; Kiørboe, Thomas

    2012-01-01

    Copepod nauplii are either ambush feeders that feed on motile prey or they produce a feeding current that entrains prey cells. It is unclear how ambush and feeding-current feeding nauplii perceive and capture prey. Attack jumps in ambush feeding nauplii should not be feasible at low Reynolds numbers due to the thick viscous boundary layer surrounding the attacking nauplius. We use high-speed video to describe the detection and capture of phytoplankton prey by the nauplii of two ambush feeding species (Acartia tonsa and Oithona davisae) and by the nauplii of one feeding-current feeding species (Temora longicornis). We demonstrate that the ambush feeders both detect motile prey remotely. Prey detection elicits an attack jump, but the jump is not directly towards the prey, such as has been described for adult copepods. Rather, the nauplius jumps past the prey and sets up an intermittent feeding current that pulls in the prey from behind towards the mouth. The feeding-current feeding nauplius detects prey arriving in the feeding current but only when the prey is intercepted by the setae on the feeding appendages. This elicits an altered motion pattern of the feeding appendages that draws in the prey. PMID:23144712

  9. Rabbits' eye globe sonographic biometry.

    PubMed

    Toni, Maria Carolina; Meirelles, Adriana Érica Wilkes Burton; Gava, Fábio Nelson; Camacho, Aparecido Antônio; Laus, José Luiz; Canola, Júlio Carlos

    2010-11-01

    To measure intraocular structures in New Zealand White breed rabbits (Oryctolagus cuniculus Linnaeus, 1758) using A-mode and B-mode ultrasound with a 20 MHz transducer. In this study, the eyes of 15 rabbits were evaluated for determination of intraocular measurements using an ophthalmic ultrasound unit able to operate in both A and B-modes. The distances from the cornea to the anterior capsule of the lens (D1), from the anterior capsule of the lens to the posterior capsule of the lens (D2), from the posterior capsule of the lens to the retina (D3) and the complete length of the eye, which corresponds to the distance from the cornea to the retina (D4) were taken. The mean values obtained were 2.70 mm (± 0.22 mm) for D1, 7.32 mm (± 0.40 mm) for D2, 7.10 mm (± 0.45 mm) for D3 and 17.12 mm (± 0.41 mm) for D4. Statistical analyses using the Student's t-test showed that there were no differences between the eyes. The study was feasible without the need of pharmacological restraint and yielded normal mean values for ocular sonographic biometry in rabbits. © 2010 American College of Veterinary Ophthalmologists.

  10. Partially coherent interferometric biometry in cataract surgery

    NASA Astrophysics Data System (ADS)

    Drexler, Wolfgang; Findl, Oliver; Menapace, Rupert; Hitzenberger, Christoph K.; Fercher, Adolf F.

    1999-02-01

    In an earlier study we showed that precise axial eye length measurement on cataract eyes is possible with the dual beam partial coherence interferometry technique (PCI). A high correlation with the standard ultrasound technique has been obtained. Recently, in a prospective study, partially coherent interferometry and ultrasound biometry were compared in cataract surgery using the SRK II formula based on US applanation biometry. Three months after surgery PCI was repeated and refractive outcome was determined. The use of PCI would have improved refractive outcome by about 30%.

  11. Bioencapsulation of Two Different Vibrio Species in Nauplii of the Brine Shrimp (Artemia franciscana)

    PubMed Central

    Gomez-Gil, Bruno; Herrera-Vega, Maria A.; Abreu-Grobois, F. Alberto; Roque, Ana

    1998-01-01

    Two groups of nauplii from the brine shrimp (Artemia franciscana) were enriched with different bacteria, and the dynamics of bacterial uptake by the nauplii were observed. This study showed that the efficiency of Artemia nauplii in bioencapsulating bacteria strongly depends on the type of bacteria used, time of exposure, and status (live or dead) of the bacteria. PMID:9603861

  12. The Kinematics of Swimming and Relocation Jumps in Copepod Nauplii

    PubMed Central

    Andersen Borg, Christian Marc; Bruno, Eleonora; Kiørboe, Thomas

    2012-01-01

    Copepod nauplii move in a world dominated by viscosity. Their swimming-by-jumping propulsion mode, with alternating power and recovery strokes of three pairs of cephalic appendages, is fundamentally different from the way other microplankters move. Protozoans move using cilia or flagella, and copepodites are equipped with highly specialized swimming legs. In some species the nauplius may also propel itself more slowly through the water by beating and rotating the appendages in a different, more complex pattern. We use high-speed video to describe jumping and swimming in nauplii of three species of pelagic copepods: Temora longicornis, Oithona davisae and Acartia tonsa. The kinematics of jumping is similar between the three species. Jumps result in a very erratic translation with no phase of passive coasting and the nauplii move backwards during recovery strokes. This is due to poorly synchronized recovery strokes and a low beat frequency relative to the coasting time scale. For the same reason, the propulsion efficiency of the nauplii is low. Given the universality of the nauplius body plan, it is surprising that they seem to be inefficient when jumping, which is different from the very efficient larger copepodites. A slow-swimming mode is only displayed by T. longicornis. In this mode, beating of the appendages results in the creation of a strong feeding current that is about 10 times faster than the average translation speed of the nauplius. The nauplius is thus essentially hovering when feeding, which results in a higher feeding efficiency than that of a nauplius cruising through the water. PMID:23115647

  13. Fetal ultrasound biometry: 1. Head reference values.

    PubMed

    Kurmanavicius, J; Wright, E M; Royston, P; Wisser, J; Huch, R; Huch, A; Zimmermann, R

    1999-02-01

    To create reliable reference ranges and calculate Z scores for fetal head ultrasound biometry using a large sample size which is evenly distributed from 12 to 42 weeks of pregnancy. A prospective, cross-sectional study. Obstetric clinics (outpatient and delivery units) at the University Hospital of Zurich. The study data were obtained from 6557 pregnant women. Only the first ultrasound examination between 12 and 42 weeks of each fetus with exactly established gestational age was used for analysis. No exclusions were made on the grounds of small-for-date birthweight, prematurity or other events several weeks after the examination. Separate regression models were fitted to estimate the mean and standard deviation at each gestational age for each parameter. A total of 6217 fetal head biparietal diameters and 5510 occipito-frontal diameters were measured. Both head circumference and cephalic index were derived in 5462 cases where both biparietal diameter and occipito-frontal diameter could be measured on the same fetus. The centile charts, tables and regression formulae for biparietal and occipito-frontal diameters, head circumference and cephalic index are presented. An application to calculate Z scores was developed using Excel (Microsoft Corporation, USA) and macros are presented in detail in the Figure 8 footnote. The comparison of our charts with those of the two most recent studies revealed almost no differences in biparietal diameter centiles. In one publication, occipito-frontal diameter charts, and in another, head circumference charts were different from the current study. We have presented centile charts, tables and regression formulae for fetal head ultrasound biometry derived from a large and minimally selected sample size in a carefully designed cross-sectional study. Complete tables and regression formulae to calculate reference ranges and Z scores are presented for use in computer-aided evaluation of fetal ultrasound biometry.

  14. Hydrodynamics and energetics of jumping copepod nauplii and copepodids.

    PubMed

    Wadhwa, Navish; Andersen, Anders; Kiørboe, Thomas

    2014-09-01

    Within its life cycle, a copepod goes through drastic changes in size, shape and swimming mode. In particular, there is a stark difference between the early (nauplius) and later (copepodid) stages. Copepods inhabit an intermediate Reynolds number regime (between ~1 and 100) where both viscosity and inertia are potentially important, and the Reynolds number changes by an order of magnitude during growth. Thus we expect the life stage related changes experienced by a copepod to result in hydrodynamic and energetic differences, ultimately affecting the fitness. To quantify these differences, we measured the swimming kinematics and fluid flow around jumping Acartia tonsa at different stages of its life cycle, using particle image velocimetry and particle tracking velocimetry. We found that the flow structures around nauplii and copepodids are topologically different, with one and two vortex rings, respectively. Our measurements suggest that copepodids cover a larger distance compared to their body size in each jump and are also hydrodynamically quieter, as the flow disturbance they create attenuates faster with distance. Also, copepodids are energetically more efficient than nauplii, presumably due to the change in hydrodynamic regime accompanied with a well-adapted body form and swimming stroke.

  15. The Norfolk Island Eye Study (NIES): rationale, methodology and distribution of ocular biometry (biometry of the bounty).

    PubMed

    Mackey, David A; Sherwin, Justin C; Kearns, Lisa S; Ma, Yaling; Kelly, John; Chu, Byoung-Sun; Macmillan, Robert; Barbour, Julie M; Wilkinson, Colleen H; Matovinovic, Elizabeth; Cox, Hannah C; Bellis, Claire; Lea, Rod A; Quinlan, Sharon; Griffiths, Lyn R; Hewitt, Alex W

    2011-02-01

    To describe the recruitment, ophthalmic examination methods and distribution of ocular biometry of participants in the Norfolk Island Eye Study, who were individuals descended from the English Bounty mutineers and their Polynesian wives. All 1,275 permanent residents of Norfolk Island aged over 15 years were invited to participate, including 602 individuals involved in a 2001 cardiovascular disease study. Participants completed a detailed questionnaire and underwent a comprehensive eye assessment including stereo disc and retinal photography, ocular coherence topography and conjunctival autofluorescence assessment. Additionally, blood or saliva was taken for DNA testing. 781 participants aged over 15 years were seen (54% female), comprising 61% of the permanent Island population. 343 people (43.9%) could trace their family history to the Pitcairn Islanders (Norfolk Island Pitcairn Pedigree). Mean anterior chamber depth was 3.32mm, mean axial length (AL) was 23.5mm, and mean central corneal thickness was 546 microns. There were no statistically significant differences in these characteristics between persons with and without Pitcairn Island ancestry. Mean intra-ocular pressure was lower in people with Pitcairn Island ancestry: 15.89mmHg compared to those without Pitcairn Island ancestry 16.49mmHg (P = .007). The mean keratometry value was lower in people with Pitcairn Island ancestry (43.22 vs. 43.52, P = .007). The corneas were flatter in people of Pitcairn ancestry but there was no corresponding difference in AL or refraction. Our study population is highly representative of the permanent population of Norfolk Island. Ocular biometry was similar to that of other white populations. Heritability estimates, linkage analysis and genome-wide studies will further elucidate the genetic determinants of chronic ocular diseases in this genetic isolate.

  16. Nonhatching Decapsulated Artemia Cysts As a Replacement to Artemia Nauplii in Juvenile and Adult Zebrafish Culture.

    PubMed

    Tye, Marc; Rider, Dana; Duffy, Elizabeth A; Seubert, Adam; Lothert, Brogen; Schimmenti, Lisa A

    2015-12-01

    Feeding Artemia nauplii as the main nutrition source for zebrafish is a common practice for many research facilities. Culturing live feed can be time-consuming and requires additional equipment to be purchased, maintained, and cleaned. Nonhatching decapsulated Artemia cysts (decaps) are a commercially available product that can be fed directly to fish. Several other ornamental fish species have been successfully cultured using decaps. Replacing Artemia nauplii with decaps could reduce the overall time and costs associated with the operation of a zebrafish facility. The objective of this study was to determine if decaps could be a suitable replacement to Artemia nauplii in juvenile and adult zebrafish culture. Wild-type zebrafish were fed one of three dietary treatments: decaps only, nauplii only, or a standard consisting of nauplii plus a commercially prepared pellet food. Survival, growth (length and weight), and embryo production were analyzed between the treatments. Fish receiving the decap diet demonstrated a significantly higher growth and embryo production when compared to the fish receiving the nauplii-only diet. When comparing the decap fish to the standard fish, no significant difference was found in mean survival, mean weight at 90 days postfertilization, or mean embryo production. It was determined that nonhatching decapsulated Artemia cysts can be used as a suitable replacement to Artemia nauplii in juvenile and adult zebrafish culture.

  17. [Biometry in cataract camps. Experiences from north Kenya].

    PubMed

    Briesen, S; Roberts, H; Karimurio, J; Kollmann, M

    2010-04-01

    Biometry has the potential to improve refractive outcomes of cataract surgery in developing countries. However, the procedure is difficult to carry out in remote areas. The feasibility of automated biometry using portable devices was assessed in an eye camp in a remote Kenyan community and reasons for failure were documented. PC-IOLs in the range of 17-27 dioptres (dpt) were implanted and a model was created to predict spherical refractive error if a standard 22 dpt lens had been used. In 104 out of 131 eyes (80%) biometry was possible. Failure to obtain K-readings in eyes with coexisting corneal pathology was the main limiting factor. The calculated mean IOL strength to achieve emmetropia was 21.56 dpt with a SD=1.96 (min: 14.78 dpt, max: 27.24 dpt). If 22 dpt lenses had been implanted around 20% would have had an error of more than 2 dpt and 7% an error of more than 3 dpt. Biometry is a challenging procedure in remote areas where comorbidities are common. However, without biometry and implantation of different IOL powers poor refractive outcome can be expected in around 20% of patients.

  18. Effect of mercuric ion on attraction to light of artemia sp nauplii.

    PubMed

    Saunders, J P; Trieff, N M; Kalmaz, E E; Uchida, T

    1985-02-01

    Living organisms exhibit a phototactic response which can be altered by certain environmental toxic chemical species. The analysis of photobehavior can help in elucidating environmental factors that influence photomotility reactions of the organisms. A method has been developed that measures the phototactic response of Artemia nauplii under the influence of mercuric ion (Hg2+) in synthetic seawater. The phototactic response of Artemia nauplii was manifested by movement of the organisms from a darkened half to lighted half of an experimental vessel containing synthetic seawater. The density as a function of time of Artemia nauplii is determined by removing aliquots from both light and dark sides and then plating on agar for counting under the dissecting microscope. Measurements consistently show a significant movement of nauplii to the lighted side within 45 min of the start of the experiments. The present investigation demonstrated that at concentrations as low as 0.010 mg HgCl2/liter there is an enhancement of phototactic effect on Artemia nauplii by mercuric ion as compared with control. The phototactic response of Artema nauplii is altered by mercuric ion in a dose-related manner, but the mechanism of this effect is presently unknown.

  19. Refractive Results Using a New Optical Biometry Device: Comparison With Ultrasound Biometry Data.

    PubMed

    Aktas, Serdar; Aktas, Hatice; Tetikoglu, Mehmet; Sagdk, Hac Murat; Özcura, Fatih

    2015-12-01

    The aim of the study was to compare the measurements of optical (AL-Scan; Nidek Co., Ltd.) and ultrasonic (Echo Scan US-800; Nidek Co., Ltd.) biometry devices and to assess refractive results after cataract surgery. Eighty-one cataractous eyes of 81 patients were included in this study. Biometry was performed using the AL-Scan and an ultrasonic biometer (USB). Axial length (AL), keratometry (K) data, and intraocular lens (IOL) power calculations using the SRK/T formula were compared. Bland-Altman analysis was used to assess the extent of agreement between AL-Scan and USB data in terms of AL measurement and IOL power calculation. The K measurements of the AL-Scan were compared to autorefractor data (Canon Autorefractor RK-F1). The AL-Scan assessed the AL as longer (average difference 0.06 ± 0.18 mm; ICC = 0.987; P < 0.001) and the IOL power as greater (average difference 0.19 ± 0.66 D; ICC = 0.964; P < 0.001) than the USB. The AL-Scan also measured average K values (average difference 0.25 ± 0.25 D; ICC = 0.985; P < 0.001) greater than those given by the autorefractor. The postoperative mean absolute error was +0.30 ± 0.04 D (minimum: -0.51 D, maximum +1.04 D). The postoperative mean K value change was 0.36 ± 0.29 D (P < 0.05). The differences between measurements afforded by the AL-Scan and USB may be clinically acceptable. Keratometric changes that develop after cataract operations compromise the attainment of good refractive outcomes.

  20. Characterization of metalloproteinase-like activities in barnacle (Balanus amphitrite) nauplii.

    PubMed

    Mannello, Ferdinando; Canesi, Laura; Faimali, Marco; Piazza, Veronica; Gallo, Gabriella; Geraci, Sebastiano

    2003-05-01

    The presence of extracellular matrix (ECM) degrading enzymes was investigated in naupliar stages of the barnacle Balanus amphitrite Darwin. The results of substrate gel-zymography and quantitative assays demonstrated that naupliar extracts contain several protease activities that are specific towards gelatin substrates; some caseinolytic activity was also detected. Substrate specificity was observed in all naupliar stages (II-VI). The gelatinolytic activities showed dependence on both Ca(2+) and Zn(2+) and inhibition by EDTA, EGTA, and 1,10-phenanthroline. Also Mg(2+) partially activated the enzymes, whereas Cd(2+), Cu(2+), Hg(2+) and Pb(2+) were inhibitory. The thermal denaturation profile was significantly different in the presence and absence of Ca(2+) and Zn(2+). Overall, the results indicate that the Ca(2+)/Zn(2+)-dependent gelatinase activities in barnacle nauplii belong to the subfamily of matrix metalloproteases. Barnacle larvae MMPs showed biochemical characteristics different from those of vertebrate MMPs but common to other gelatinases from marine invertebrates: they were unaffected by several protease inhibitors and insensitive to specific activators/inhibitors of vertebrate MMPs. The presence of MMP-like activities in different naupliar stages suggests a constitutive role for these enzymes in ECM remodeling during barnacle larvae growth and development.

  1. Delivery prediction in pregnant women with spontaneous preterm birth using fetal adrenal gland biometry.

    PubMed

    Lemos, Aline Pinto; Feitosa, Francisco Edson de Lucena; Araujo Júnior, Edward; Feitosa, Helvécio Neves; Pereira, João Gabriel Damasceno; Mota, Rosa Maria Salani; Carvalho, Francisco Herlânio Costa

    2016-12-01

    To assess the prediction of delivery within 7 days in pregnant women who showed symptoms of spontaneous preterm birth (PB) by means of fetal adrenal gland biometry and to compare these predictions with the cervical length (CL) measurement. We performed a prospective cross-sectional study with 53 pregnant women between 24 and 36 weeks of gestation. An ultrasound exam was performed for each participant to obtain the CL measurement (transvaginal route) and fetal adrenal gland biometry on day 1 of their hospital admission because of symptoms of spontaneous PB. The main outcome measure was the time between the ultrasound exam and delivery, which was classified into two groups: delivery  ≤7 days and delivery  >7 days. A receiver operating characteristics (ROC) curve was performed to define the cutoffs for sensitivity and specificity. The prevalence of delivery within 7 days was 35.8%, which showed a statistically significant difference from the depth of the central zone of the fetal adrenal gland (p  =  0.036). The cutoff for the depth of the central zone of the fetal adrenal gland was 7.2 mm (sensitivity 66.7%, specificity 61.8% and accuracy 63.5%). These values were not significantly different than the cutoffs for cervical length measurement: 20 mm (p  =  0.267) and 9 mm (p  =  0.118). The biometry for the central zone of the fetal adrenal gland predicted delivery within 7 days in pregnant women with spontaneous PB and had a predictive accuracy similar to that of CL measurement.

  2. Three-Versus Two-Dimensional Sonographic Biometry for Predicting Birth Weight and Macrosomia in Diabetic Pregnancies.

    PubMed

    Tuuli, Methodius G; Kapalka, Kristen; Macones, George A; Cahill, Alison G

    2016-09-01

    The purpose of this study was to test the hypothesis that a formula incorporating 3-dimensional (3D) fractional thigh volume would be superior to the conventional 2-dimensional (2D) formula of Hadlock et al (Am J Obstet Gynecol 1985; 151:333-337) for predicting birth weight and macrosomia. We conducted a prospective cohort study of pregnancies complicated by pregestational or gestational diabetes and delivered after 38 weeks. Two-dimensional and 3D sonographic examinations were performed for fetal biometry and factional thigh volumes at 34 to 37 weeks. Fetal weight was estimated by Hadlock's 2D formula IV, which uses only 2D biometry, and formula 6 from Lee et al (Ultrasound Obstet Gynecol 2009; 34:556-565), which incorporates 3D fractional thigh volume and 2D biometry. The gestation-adjusted projection method was used to estimate predicted birth weights from 2D and 3D estimates. The primary outcome was fetal macrosomia, which was defined as birth weight of 4000 g or higher. A total of 115 women with diabetes met inclusion criteria, and 17 (14.8%) delivered macrosomic neonates. The mean percentage error was significantly lower for the 2D than the 3D projected estimate (1.0% versus 12.0%; P < .01). The standard deviation of the mean percentage error was also significantly lower for the 2D projected estimate (10.2% versus 17.2%; P< .01). Two-dimensional biometry was overall superior to 3D biometry for predicting macrosomia (area under the receiver operating characteristic curve, 0.88 versus 0.75; P = .03). Specificity was significantly higher for 2D biometry (85% versus 66%; P < .01), whereas the difference in sensitivity was not statistically significant (59% versus 71%; P = .22). In this study, the Hadlock 2D formula was superior to the 3D method for predicting birth weight and macrosomia in diabetic women when used approximately 2 weeks before delivery, based on the gestation-adjusted projection method.

  3. A new protocol for ecotoxicological assessment of seawater using nauplii of Tisbe biminiensis (Copepoda:Harpacticoida).

    PubMed

    Lavorante, Beatriz R B O; Oliveira, Deloar D; Costa, Bruno V M; Souza-Santos, Lília P

    2013-09-01

    Copepods are largely used in toxicity tests. The nauplii of these organisms are more sensitive to contaminants than the adult stage. The aim of the present study was to test a protocol for the use of nauplii of the copepod Tisbe biminiensis in the ecotoxicological assessment of seawater. The sensitivity of these organisms to zinc sulphate (ZnSO4·7H2O) was also determined. The following conditions were established for the protocol based on the best development of nauplii to copepodites: 72-h duration, the microalga Chaetocerus gracilis at 2.5×10(5)cellsmL(-1) as feed and incubation temperature of 28°C. In the zinc sulphate sensitivity tests, EC50-72 h and LC50/72 h were 3.25±0.59 mg L(-1) and 3.46±0.72 mg L(-1), respectively, as estimated by the final number of copepodites and total number of live animals in relation to the mean number of inoculated nauplii. The estimated NOEC was 2.0 mg L(-1). The test developed is fast and not labour intensive. T. biminiensis nauplii exhibit sensitivity to zinc sulphate similar to that of other species of copepods employed in water toxicity tests, demonstrating the usefulness of these organisms in ecotoxicological studies involving samples of environmental seawater. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Wavefront Derived Refraction and Full Eye Biometry in Pseudophakic Eyes.

    PubMed

    Mao, Xinjie; Banta, James T; Ke, Bilian; Jiang, Hong; He, Jichang; Liu, Che; Wang, Jianhua

    2016-01-01

    To assess wavefront derived refraction and full eye biometry including ciliary muscle dimension and full eye axial geometry in pseudophakic eyes using spectral domain OCT equipped with a Shack-Hartmann wavefront sensor. Twenty-eight adult subjects (32 pseudophakic eyes) having recently undergone cataract surgery were enrolled in this study. A custom system combining two optical coherence tomography systems with a Shack-Hartmann wavefront sensor was constructed to image and monitor changes in whole eye biometry, the ciliary muscle and ocular aberration in the pseudophakic eye. A Badal optical channel and a visual target aligning with the wavefront sensor were incorporated into the system for measuring the wavefront-derived refraction. The imaging acquisition was performed twice. The coefficients of repeatability (CoR) and intraclass correlation coefficient (ICC) were calculated. Images were acquired and processed successfully in all patients. No significant difference was detected between repeated measurements of ciliary muscle dimension, full-eye biometry or defocus aberration. The CoR of full-eye biometry ranged from 0.36% to 3.04% and the ICC ranged from 0.981 to 0.999. The CoR for ciliary muscle dimensions ranged from 12.2% to 41.6% and the ICC ranged from 0.767 to 0.919. The defocus aberrations of the two measurements were 0.443 ± 0.534 D and 0.447 ± 0.586 D and the ICC was 0.951. The combined system is capable of measuring full eye biometry and refraction with good repeatability. The system is suitable for future investigation of pseudoaccommodation in the pseudophakic eye.

  5. Wavefront Derived Refraction and Full Eye Biometry in Pseudophakic Eyes

    PubMed Central

    Mao, Xinjie; Banta, James T.; Ke, Bilian; Jiang, Hong; He, Jichang; Liu, Che; Wang, Jianhua

    2016-01-01

    Purpose To assess wavefront derived refraction and full eye biometry including ciliary muscle dimension and full eye axial geometry in pseudophakic eyes using spectral domain OCT equipped with a Shack-Hartmann wavefront sensor. Methods Twenty-eight adult subjects (32 pseudophakic eyes) having recently undergone cataract surgery were enrolled in this study. A custom system combining two optical coherence tomography systems with a Shack-Hartmann wavefront sensor was constructed to image and monitor changes in whole eye biometry, the ciliary muscle and ocular aberration in the pseudophakic eye. A Badal optical channel and a visual target aligning with the wavefront sensor were incorporated into the system for measuring the wavefront-derived refraction. The imaging acquisition was performed twice. The coefficients of repeatability (CoR) and intraclass correlation coefficient (ICC) were calculated. Results Images were acquired and processed successfully in all patients. No significant difference was detected between repeated measurements of ciliary muscle dimension, full-eye biometry or defocus aberration. The CoR of full-eye biometry ranged from 0.36% to 3.04% and the ICC ranged from 0.981 to 0.999. The CoR for ciliary muscle dimensions ranged from 12.2% to 41.6% and the ICC ranged from 0.767 to 0.919. The defocus aberrations of the two measurements were 0.443 ± 0.534 D and 0.447 ± 0.586 D and the ICC was 0.951. Conclusions The combined system is capable of measuring full eye biometry and refraction with good repeatability. The system is suitable for future investigation of pseudoaccommodation in the pseudophakic eye. PMID:27010674

  6. Normative biometry of the fetal brain using magnetic resonance imaging.

    PubMed

    Kyriakopoulou, Vanessa; Vatansever, Deniz; Davidson, Alice; Patkee, Prachi; Elkommos, Samia; Chew, Andrew; Martinez-Biarge, Miriam; Hagberg, Bibbi; Damodaram, Mellisa; Allsop, Joanna; Fox, Matt; Hajnal, Joseph V; Rutherford, Mary A

    2016-11-24

    The fetal brain shows accelerated growth in the latter half of gestation, and these changes can be captured by 2D and 3D biometry measurements. The aim of this study was to quantify brain growth in normal fetuses using Magnetic Resonance Imaging (MRI) and to produce reference biometry data and a freely available centile calculator ( https://www.developingbrain.co.uk/fetalcentiles/ ). A total of 127 MRI examinations (1.5 T) of fetuses with a normal brain appearance (21-38 gestational weeks) were included in this study. 2D and 3D biometric parameters were measured from slice-to-volume reconstructed images, including 3D measurements of supratentorial brain tissue, lateral ventricles, cortex, cerebellum and extra-cerebral CSF and 2D measurements of brain biparietal diameter and fronto-occipital length, skull biparietal diameter and occipitofrontal diameter, head circumference, transverse cerebellar diameter, extra-cerebral CSF, ventricular atrial diameter, and vermis height, width, and area. Centiles were constructed for each measurement. All participants were invited for developmental follow-up. All 2D and 3D measurements, except for atrial diameter, showed a significant positive correlation with gestational age. There was a sex effect on left and total lateral ventricular volumes and the degree of ventricular asymmetry. The 5th, 50th, and 95th centiles and a centile calculator were produced. Developmental follow-up was available for 73.1% of cases [mean chronological age 27.4 (±10.2) months]. We present normative reference charts for fetal brain MRI biometry at 21-38 gestational weeks. Developing growth trajectories will aid in the better understanding of normal fetal brain growth and subsequently of deviations from typical development in high-risk pregnancies or following premature delivery.

  7. Fetal ultrasound biometry: 2. Abdomen and femur length reference values.

    PubMed

    Kurmanavicius, J; Wright, E M; Royston, P; Zimmermann, R; Huch, R; Huch, A; Wisser, J

    1999-02-01

    To create reliable reference ranges and calculate Z scores for fetal abdomen and femur ultrasound biometry using a large sample size which is evenly distributed from 12 to 42 weeks of pregnancy. A prospective, cross-sectional study. Obstetric clinics (outpatient and delivery units) at the University Hospital of Zurich. The study data were obtained from 6557 pregnant women. Only the first ultrasound examination between 12 and 42 weeks of each fetus with certainly established gestational age was used for analysis. No exclusions were made on the grounds of small-for-date birthweight, prematurity or other events several weeks after the examination. Separate regression models were fitted to estimate the mean and standard deviation at each gestational age for each parameter. A total of 5807 mean abdominal diameters and abdominal circumferences were derived from fetal transverse and anterio-posterior fetal abdominal diameter measurements. Fetal femur length was measured in 5860 instances. The charts, tables and regression formulae of the biometrical measurements are presented. A comparison of our charts with others showed no significant difference. Only Merz's centiles for abdominal biometry were lower and for femur length higher than ours. An application to calculate Z scores was developed using Excel (Microsoft Corporation, USA); the macros are presented in detail in the Figure 6 footnote. We have presented centile charts, tables and formulae for fetal abdominal diameter and circumference and femur length derived from a large and minimally selected sample size in a carefully designed cross-sectional study. Complete tables and regression formulae to calculate reference ranges and Z scores are presented to use in computer-aided evaluation of fetal ultrasound biometry.

  8. Fetal Biometry of Head Circumference for Malaysian Pregnant Women

    NASA Astrophysics Data System (ADS)

    Ramli, Remsen Maizan; Jaafar, M. S.; Ismail, N. E.; Saltani, Hend A. A.; Ahmad, A. L.; Bermakai, M. Yahaya

    2010-07-01

    The purpose of this research is to study the fetal head circumference (HC) biometry for local population. Retrospective study was selected, done at Hospital Pulau Pinang and 5551 files of pregnant women were collected. The HC mean values of this study (HCmean) was compared with other published studies to see whether there was any difference between the various populations in the world. Comparison of means, regression analysis and paired sample t-test in SPSS software version 11.5 were used in the analysis. A total of 9874 HC data (mm) were recorded for gestational age (GA) of 12 to 41 weeks. The HC growth rate in second trimester (11.32 mm/week) has decreased to nearly half than in third trimester (5.53 mm/week). The HCmean was found to be highly significant difference (SD) than other 9 studies and only lower than HC values of USA, UK and Zimbabwe populations. The HC values of German show close similarity with HCmean. From 45 comparisons done, more than three-quarter of the comparisons resulted as SD (37) compared to insignificant differences (8). Consequently, each country should have their own standard HC of fetus biometry of the various gestations for their own population.

  9. Challenges and approaches in modern biometry and IOL calculation.

    PubMed

    Haigis, Wolfgang

    2012-01-01

    The introduction of new intraocular lenses (IOLs), industry marketing to the public and patient expectations has warranted increased accuracy of IOL power calculations. Toric IOLs, multifocal IOLs, aspheric IOLs, phakic lenses, accommodative lenses, cases of refractive lens exchange and eyes that have undergone previous refractive surgery all require improved clinical measurements and IOL prediction formulas. Hence, measurement techniques and IOL calculation formulas are essential factors that affect the refractive outcome. Measurement with ultrasound has been the historic standard for measurement of ocular parameters for IOL calculation. However the introduction of optical biometry using partial coherence interferometry (PCI) has steadily established itself as the new standard. Additionally, modern optical instruments such as Scheimpflug cameras and optical coherence tomographers are being used to determine corneal power that was normally the purview of manual keratometry and topography. A number of methods are available to determine the IOL power including the empirical, analytical, numerical or combined methods. Ray tracing techniques or paraxial approximation by matrix methods or classical analytical 'IOL formulas' are actively used in for the prediction of IOL power. There is no universal formula for all cases - phakic and pseudophakic cases require different approaches, as do short eyes, long eyes, astigmatic eyes or post-refractive surgery eyes. Invariably, IOLs are characterized by different methods and lens constants, which require individual optimization. This review describes the current methods for biometry and IOL calculation.

  10. Comparison of IOL--master and ultrasound biometry in preoperative intra ocular lens (IOL) power calculation.

    PubMed

    Kolega, Marija Škara; Kovačević, Suzana; Čanović, Samir; Pavičić, Ana Didović; Bašić, Jadranka Katušić

    2015-03-01

    Postoperative refractive outcome largely depends on the accuracy of calculating power of implanted IOL. Lens power calculation can be done by conventional ultrasound biometry and partial coherence laser interferometry (IOL Master). The aim was to compare the accuracy of IOL power calculations using conventional ultrasound biometry and partial coherence laser interferometry.40 eyes were included in this prospective randomized trial. Twenty eyes underwent IOL master and 20 eyes had aplanation ultrasound biometry. There were included only eyes with age-related cataract and postoperative natural visual acuity (VA) 0.7. Visual acuity was performed 6 weeks after cataract surgery. After 6 weeks best natural visual acuity were 0.9 (± 0.1) in IOL-Master group and 0.85 (± 0.15) in ultrasound biometry. The postoperative mean absolute refractive error was 0.75 (± 0.5) D for ultrasound biometry and 0.50 (± 0.50) D for IOL-Master. Optical biometry with the IOL-Master proved to be slightly more accurate than ultrasound biometry for IOL power calculation.

  11. Fetal Biometry Studies of Malaysian Pregnant Women and Comparison with International Charts

    NASA Astrophysics Data System (ADS)

    Adam, N.; Ramli, R. M.; Jaafar, M. S.

    2010-07-01

    Fetal biometry is a measurement done on fetus anatomy to relate the fetus growth with gestational age (GA). In this study [1], fetal biometry that was studied consists of biparietal diameter (BPD), abdominal circumference (AC) and femur length (FL). Studies were carried out at Maternity Unit, Hospital Pulau Penang. From the finding, it is understood that fetal biometry distinguish the normal from abnormal fetal structures and it vary among different populations, depending upon their racial [2,3] and nutrition [4,5,6]. True findings are valuable in estimating the gestational age of the fetus, abnormalities in fetus and the consideration of maternal health specific to the Malaysian population.

  12. [Individual postoperative refraction after cataract surgery -- a comparison of optical and acoustical biometry].

    PubMed

    Kutschan, A; Wiegand, W

    2004-09-01

    Optical biometry with the IOL-Master is an innovative technique that claims to improve the refractive results of cataract surgery compared to acoustical biometry. In 140 consecutive non-selected eyes prior to cataract surgery firstly an optical biometry (IOL-Master, Zeiss, V.2.02) and secondly an ultrasound biometry (Sonomed) were carried out. Cataract surgery was performed using either a PMMA-IOL (n = 56) or an acrylic IOL (n = 84). The PMMA-IOL's were implanted in the capsular bag via a scleral tunnel. The acrylic-IOL's were implanted via a clear cornea incision in the capsular bag. The length of the globe was analysed and the deviations between the postoperative refraction after 3 month and the preoperative planned refraction were compared. The mean axial length difference between optical biometry and acoustical biometry was 0.19 mm in the PMMA-lens group and 0.16 mm in the acrylic-lens group. The deviation of postoperative refraction (spherical mean) from the planned refraction was 0.46 +/- 0.88 D in the PMMA-IOL group and 0.25 +/- 0.77 D in the acrylic IOL group when biometry was performed by ultrasonography. When optical biometry was performed the respective values were 1.15 +/- 0.83 D in the PMMA-IOL group and 0.84 +/- 0.75 D in the acrylic IOL group. The differences in mean postoperative refraction of optical and acoustical biometry can be compensated by adaptation of the A constants. The standard deviation of the difference between the postoperative refraction and the preoperatively planned refraction - that means the individual deviations between postoperative refraction and preoperatively planned refraction - were almost identical in optical and acoustical biometry. Optical biometry represents a significant simplification in the course of investigation prior to cataract surgery. The claim of optical biometry, however, to gain a higher precision and thus a significantly better prediction of individual postoperative refraction after cataract surgery is not

  13. A short-term swimming speed alteration test with nauplii of Artemia franciscana.

    PubMed

    Morgana, Silvia; Estévez-Calvar, Noelia; Gambardella, Chiara; Faimali, Marco; Garaventa, Francesca

    2017-09-14

    The presence of toxicant needs to be assessed within short time in order to effectively protect the aquatic environment from serious threat. Based on the observation that at high temperatures aquatic organisms become more vulnerable to stressors than those maintained at room temperature, a new test was developed. The proposed bioassay consisted in the evaluation of the swimming speed alteration (SSA) of nauplii of Artemia franciscana incubated at 39°C (± 1) for 6h, using a Swimming Behavior Recorder system (SBR). A comparative ecotoxicological study between the 6h SSA test and the 24h mortality test was carried out in order to validate the new method in terms of sensitivity by means of EC50 values. The bioassay was applied to screen different toxicants: K2Cr2O7, Cu(SO4)2, NaClO, SDS and Sertraline hydrochloride. The EC50s calculated for the short-term SSA test and those of the mortality test showed comparable values. For all toxicants, the 6h SSA test was proved to be as sensitive as the 24h mortality test. The method developed in this study is the first temperature-based toxicity test with nauplii of Artemia franciscana and it represents an attractive assay in ecotoxicology because of its convenience in terms of time and costs, feasibility and sensitivity. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Influence of UVB radiation on the lethal and sublethal toxicity of dispersed crude oil to planktonic copepod nauplii.

    PubMed

    Almeda, Rodrigo; Harvey, Tracy E; Connelly, Tara L; Baca, Sarah; Buskey, Edward J

    2016-06-01

    Toxic effects of petroleum to marine zooplankton have been generally investigated using dissolved petroleum hydrocarbons and in the absence of sunlight. In this study, we determined the influence of natural ultraviolet B (UVB) radiation on the lethal and sublethal toxicity of dispersed crude oil to naupliar stages of the planktonic copepods Acartia tonsa, Temora turbinata and Pseudodiaptomus pelagicus. Low concentrations of dispersed crude oil (1 μL L(-1)) caused a significant reduction in survival, growth and swimming activity of copepod nauplii after 48 h of exposure. UVB radiation increased toxicity of dispersed crude oil by 1.3-3.8 times, depending on the experiment and measured variables. Ingestion of crude oil droplets may increase photoenhanced toxicity of crude oil to copepod nauplii by enhancing photosensitization. Photoenhanced sublethal toxicity was significantly higher when T. turbinata nauplii were exposed to dispersant-treated oil than crude oil alone, suggesting that chemical dispersion of crude oil may promote photoenhanced toxicity to marine zooplankton. Our results demonstrate that acute exposure to concentrations of dispersed crude oil and dispersant (Corexit 9500) commonly found in the sea after oil spills are highly toxic to copepod nauplii and that natural levels of UVB radiation substantially increase the toxicity of crude oil to these planktonic organisms. Overall, this study emphasizes the importance of considering sunlight in petroleum toxicological studies and models to better estimate the impact of crude oil spills on marine zooplankton. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Full OCT anterior segment biometry: an application in cataract surgery.

    PubMed

    Ortiz, Sergio; Pérez-Merino, Pablo; Durán, Sonia; Velasco-Ocana, Miriam; Birkenfeld, Judith; de Castro, Alberto; Jiménez-Alfaro, Ignacio; Marcos, Susana

    2013-03-01

    In vivo three-dimensional (3-D) anterior segment biometry before and after cataract surgery was analyzed by using custom high-resolution high-speed anterior segment spectral domain Optical Coherence Tomography (OCT). The system was provided with custom algorithms for denoising, segmentation, full distortion correction (fan and optical) and merging of the anterior segment volumes (cornea, iris, and crystalline lens or IOL), to provide fully quantitative data of the anterior segment of the eye. The method was tested on an in vitro artificial eye with known surfaces geometry at different orientations and demonstrated on an aging cataract patient in vivo. Biometric parameters CCT, ACD/ILP, CLT/ILT Tilt and decentration are retrieved with a very high degree of accuracy. IOL was placed 400 μm behind the natural crystalline lens, The IOL was aligned with a similar orientation of the natural lens (2.47 deg superiorly), but slightly lower amounts (0.77 deg superiorly). The IOL was decentered superiorly (0.39 mm) and nasally (0.26 mm).

  16. Small animal ocular biometry using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Ruggeri, Marco; Kocaoglu, Omer; Uhlhorn, Stephen; Borja, David; Urs, Raksha; Chou, Tsung-Han; Porciatti, Vittorio; Parel, Jean-Marie; Manns, Fabrice

    2010-02-01

    A custom-built OCT system was used to obtain images of the whole mouse eye. We developed a semi-automated segmentation method to detect the boundaries of the anterior and posterior corneal, lens and retinal surfaces as well as the anterior surface of the iris. The radii of curvature of the surfaces were calculated using a conic section fit of each boundary. Image distortions due to refraction of the OCT beam at the successive boundaries were corrected using a ray-tracing algorithm. Corrected ocular distances, radii of curvature of the cornea and lens surfaces, and anterior chamber angle were obtained on 3 C57BL/6J mice. In vivo imaging of the whole eye, segmentation, conic function fits and correction were successful in all three animals. The posterior lens surface of one mouse could not be fit accurately with a conic section. Biometric parameters of C57BL/6J mice compared well with previous published data obtained from histological sections. The study demonstrates the feasibility of quantitative in vivo biometry of mouse models.

  17. Summertime Ciliate and Copepod Nauplii Distributions and Micro-zooplankton Herbivorous Activity in the Laizhou Bay, Bohai Sea, China

    NASA Astrophysics Data System (ADS)

    Zhang, W.; Wang, R.

    2000-07-01

    The abundance and biomass of ciliated protozoa and copepod nauplii were investigated at 21 grid stations and two anchored stations in the Laizhou Bay, Bohai Sea, China in June 1998. Dilution incubations were carried out to investigate micro-zooplankton grazing pressure at the anchored stations during spring tide and neap tide. The dominant species were Tintinnopsis amoyensis , T. chinglanensis, T. pallida and aloricate ciliates. A total of 13 species of tintinnids were found. The total abundance of ciliates and nauplii ranged from 30 to 2390 ind l -1at grid stations. Tintinnopsis amoyensis was the only ciliate found at the anchored stations and in concentrations which varied from 0 to 6700 ind l -1. The spatial distribution of ciliates was patchy. Tintinnopsis amoyensis and T. pallida were distributed in the Weihe River mouth and Xiaoqinghe River mouth respectively. The aloricate ciliates, T. chinglanensis and Codonellopsis ostenfeldi dominated offshore in sequence. The water mixing process may affect the spatial pattern of the dominant ciliate species. The abundance and biomass of copepod nauplii were in the range of 0-140 ind l -1and 0-7 μg C 1 -1respectively, with the peak appearing at grid station 15. The total biomass of ciliates and copepod nauplii was in the range of 1·5-25 μg C 1 -1. Water column biomass of ciliates and nauplii varied from 2·37 to 52·3 mg C m -2. At the anchored stations, the phytoplankton growth rates ranged from undetectable to 0·21 d -1and micro-zooplankton grazing rates from 0·13 to 0·57 d -1. The grazing pressure of micro-zooplankton were 12 to 43% of the chlorophyll standing stock and 84 to 267% of the chlorophyll production per day.

  18. Effect of different microcystin profiles on toxin bioaccumulation in common carp (Cyprinus carpio) larvae via Artemia nauplii.

    PubMed

    El Ghazali, Issam; Saqrane, Sanaa; Carvalho, António Paulo; Ouahid, Youness; Del Campo, Francisca F; Oudra, Brahim; Vasconcelos, Vitor

    2010-07-01

    In this study, a 12-day growth trial was conducted to compare the effect of the variation in microcystin (MC) composition in two Microcystis aeruginosa bloom samples on the growth performance and MC accumulation/transfer in the common carp (Cyprinus carpio L.) larvae. Fish were fed Artemia salina nauplii that had been preexposed to extracts from two M. aeruginosa natural blooms with different microcystins (MCs) profiles. Bloom A had MC-LR as major toxin (74.05%) while bloom B had a diversity of MC (MC-RR; MC-(H4)YR; MC-YR; MC-LR; MC-FR; MC-WR) with no dominance of MC-LR. Newly-hatched Artemia nauplii were exposed separately to the two M. aeruginosa extracts A and B (100 microg L(-1)EqMC-LR) for 2h. The MC concentration in the nauplii was 73.60+/-7.88ngEqMC-LRg(-1)FW (n=4, mean+/-SE) for bloom A and 87.04+/-10.31ngEqMC-LRg(-1)FW for bloom B. These contaminated nauplii were given at the same ration to different groups (A and B) of fish larvae. Larval weight and length from day 9 were significantly different between groups A and B, and in both cases lower than that of a control group fed non-exposed nauplii. MCs accumulation by larvae, inversely correlated with the growth performance, was also significantly different between groups A and B (37.43+/-2.61 and 54.55+/-3.01ngEqMC-LRg(-1) FW, respectively, at the end of the experimental period). These results indicate that MC profile of a bloom may have differential effects on toxin accumulation/transfer and toxicity. Copyright (c) 2009 Elsevier Inc. All rights reserved.

  19. Molecular cloning and expression analysis of the retinoid X receptor (RXR) gene in golden pompano Trachinotus ovatus fed Artemia nauplii with different enrichments.

    PubMed

    Yang, Qibin; Zheng, Panlong; Ma, Zhenhua; Li, Tao; Jiang, Shigui; Qin, Jian G

    2015-12-01

    The retinoid X receptors (RXRs) are involved in the skeletal development and other biological process such as blood vessel formation and metabolism. Partial sequences of RXRα and β genes were obtained, and their expressions were quantified on golden pompano Trachinotus ovatus at 28 days post hatching (DPH) to explore the molecular response to nutritional manipulation in fish larvae. As live food, Artemia nauplii were separately enriched with Nannochloropsis and Algamac 3080 and non-enriched Artemia nauplii (control) for fish feeding. The expressions of RXRs were detected in the embryos and fish larvae at early stages, suggesting that the skeletal development in golden pompano initiated before yolk re-sorption completion. Fish fed non-enriched Artemia nauplii ended up with higher jaw malformation. The highest specific growth rate was obtained when fish were fed with the Artemia nauplii enriched with Algamac 3080, and the lowest growth rate was observed when fish were fed with unenriched Artemia nauplii. The highest survival was obtained when fish were fed with non-enriched or Nannochloropsis-enriched Artemia nauplii. This study indicates that the use of enriched formula for Artemia nauplii can significantly affect the expression levels of RXRs and jaw malformation of golden pompano larvae, but there is no clear correlation between RXRs expressions and malformation rates when fish are subjected to nutrient challenge.

  20. Comparison of ocular biometry measurements by applanation and immersion A-scan techniques.

    PubMed

    Ademola-Popoola, Dupe S; Nzeh, Donald A; Saka, Sadiat E; Olokoba, Lateefat B; Obajolowo, Tokunbo S

    2015-01-01

    The study compared ocular biometry values using applanation and immersion techniques to determine the most applicable method for our tertiary training centre where personnel with different levels of experience and expertise in biometry take measurements used in calculation of required intraocular lens before cataract surgery. The study was a prospective cross-sectional comparative study of different techniques of ocular biometry from diagnostic equipment (biometry probe 10 MHz Sonomed(®) A-scan (PACSCAN 300A, USA). Measurement variables were obtained among children and adults undergoing cataract surgery. Scleral (Prager) shell was used for the immersion technique followed by the contact technique by the same examiner. The biometry values of 92 eyes of 92 adult were taken. Their ages ranged from 18 to 95 years with a mean of 64.7 (SD ± 12.9) years. There were 55 (59.8%) males and 37 (40.2%) females, with a male to female ratio of 1.5:1. Average axial length (22.0-24.4 mm) eyes were the most common eyes measured in 75 (81.5%) of the cases. The means of the axial lengths biometry values with immersion and contact technique were 23.66(±1.36) and 23.46 mm (±1.46); the axial length differences was 0.2 ± 0.26 mm (range 0.0-0.94 mm) and statistically significant (95% CI of the Difference 0.15 to 0.26, p = 0.000). The Standard deviation SD (mm) of Individual Eye Axial Length showed a mean of 0.03 ± 0.04 (0.0-0.3) mm for immersion and for contact technique 0.14 ± 0.12(0.0-0.6)mm. There was a significant difference in ocular biometry measurement with the contact and immersion ultrasound techniques. The immersion technique had better repeatability, thus it is ideal in a training hospital setting in a typical in sub-Saharan Africa who have limited resources to employ a dedicated person to do biometry; and where the different operators of A-scan machines have different levels of experience and expertise.

  1. A screening of medicinal compounds for their effect on egg strings and nauplii of the salmon louse Lepeophtheirus salmonis (Krøyer).

    PubMed

    Aaen, S M; Hamre, L A; Horsberg, T E

    2016-10-01

    Egg strings and nauplii of the salmon louse Lepeophtheirus salmonis were exposed to a variety of medicinal compounds at 50 mg L(-1) for 30 min in two experiment series. This medicine concentration was selected as a starting point for a screening series. Hatching of egg strings and development to copepodid larvae were monitored in one experiment, and the survival and development of nauplii were monitored in the other. Two compounds, emamectin benzoate and cypermethrin, inhibited hatching effectively. Several compounds affected nauplii, either directly or through inhibiting development to the infective stage. A total of 50 mg L(-1) of azamethiphos, cypermethrin, emamectin benzoate and propoxur was lethal to >70% of the larvae. Diflubenzuron, fenoxycarb, pymetrozine, pyriprole and tebufenozide diminished the ability of nauplii developing to copepodids. © 2016 John Wiley & Sons Ltd.

  2. On Tetragonicipitidae (Crustacea, Copepoda) from the Channel of São Sebastiao, Brazil, with description of their nauplii and two new species of Phyllopodopsyllus.

    PubMed

    Björnberg, Tagea; Kihara, Terue C

    2013-01-01

    Phyllopodopsyllus iuanamai sp. nov. and Phyllopodopsylluspseudokunzi sp. nov. are described from specimens collected in the Channel of Sao Sebastiao (State of Sao Paulo, Brazil). The nauplii of P. iuanamai, P. pseudokunzi, P aegypticus Nicholls, 1944 are described, additional information is given on nauplii and morphology of the adult P. setouchiensis Kitazima, 1981, and on the nauplius of Laophontella horrida (Por, 1964). These represent first records of P. aegypticus and L. horrida in Brazilian waters.

  3. beta-Hydroxybutyrate in developing nauplii of brine shrimp (Artemia franciscana K.) under feeding and non-feeding conditions.

    PubMed

    Weltzien, F A; Hemre, G I; Evjemo, J O; Olsen, Y; Fyhn, H J

    2000-01-01

    Body content of beta-hydroxybutyrate, and individual dry mass, carbon content, and survival rate, were studied in developing nauplii of the brine shrimp Artemia franciscana K. from hatching to 96-97 h post hatching at 27 +/- 1 degrees C. The effect of two diets was studied in the experiment: Super Selco (SS) with a high lipid content; and Protein Selco (PS) with a high protein content. A starving group (S) was used as reference. The level of beta-hydroxybutyrate at hatching was 0.6 nmol.ind-1; it increased to 1.0-1.5 nmol.ind-1 in the SS- and S-groups, while in the PS-group it remained stable between 0.6-0.8 nmol.ind-1. At 60-80 h post hatch in the SS- and S-groups, the levels of beta-hydroxybutyrate were similar to the initial levels. The survival rate remained higher than 95% until 24 h post hatching in all groups. At the end of the experiment, the survival rate was 63% in the PS-group, 13% in the S-group and 3% in the SS-group. The Artemia nauplii individual dry mass and carbon content remained relatively stable in the SS-group; both parameters showed a significant increase in the PS-group and a significant decrease in the S-group. The results suggest that Artemia nauplii utilise ketone bodies as a fuel during development and growth, but that ketone catabolism may be overloaded by excessive lipid feeding resulting in increased mortality and possibly a ketotic acidosis.

  4. Spatiotemporal distribution of protozooplankton and copepod nauplii in relation to the occurrence of giant jellyfish in the Yellow Sea

    NASA Astrophysics Data System (ADS)

    Wang, Lu; Xu, Kuidong

    2013-11-01

    The occurrence of the giant jellyfish, Nemopilema nomurai, has been a frequent phenomenon in the Yellow Sea. However, the relationship between the giant jellyfish and protozoa, in particular ciliates, remains largely unknown. We investigated the distribution of nanoflagellates, ciliates, Noctiluca scintillans, and copepod nauplii along the transect 33°N in the Yellow Sea in June and August, 2012, during an occurrence of the giant jellyfish, and in October of that year when the jellyfish was absent. The organisms studied were mainly concentrated in the surface waters in summer, while in autumn they were evenly distributed in the water column. Nanoflagellate, ciliate, and copepod nauplii biomasses increased from early June to August along with jellyfish growth, the first two decreased in October, while N. scintillans biomass peaked in early June to 3 571 μg C/L and decreased in August and October. In summer, ciliate biomass greatly exceeded that of copepod nauplii (4.61-15.04 μg C/L vs. 0.34-0.89 μg C/L). Ciliate production was even more important than biomass, ranging from 6.59 to 34.19 μg C/(L·d) in summer. Our data suggest a tight and positive association among the nano-, micro-, and meso-zooplankton in the study area. Statistical analysis revealed that the abundance and total production of ciliate as well as loricate ciliate biomass were positively correlated with giant jellyfish biomass, indicating a possible predator-prey relationship between ciliates and giant jellyfish. This is in contrast to a previous study, which reported a significant reduction in ciliate standing crops due to the mass occurrence of N. nomurai in summer. Our study indicates that, with its high biomass and, in particular, high production ciliates might support the mass occurrence of giant jellyfish.

  5. Laser optical method of visualizing cutaneous blood vessels and its applications in biometry and photomedicine

    NASA Astrophysics Data System (ADS)

    Asimov, M. M.; Asimov, R. M.; Rubinov, A. N.

    2011-05-01

    We propose and examine a new approach to visualizing a local network of cutaneous blood vessels using laser optical methods for applications in biometry and photomedicine. Various optical schemes of the formation of biometrical information on the architecture of blood vessels of skin tissue are analyzed. We developed an optical model of the interaction of the laser radiation with the biological tissue and a mathematical algorithm of processing of measurement results. We show that, in medicine, the visualization of blood vessels makes it possible to calculate and determine regions of disturbance of blood microcirculation and to control tissue hypoxia, as well as to maintain the local concentration of oxygen at a level necessary for the normal cellular metabolism. We propose noninvasive optical methods for modern photomedicine and biometry for diagnostics and elimination of tissue hypoxia and for personality identification and verification via the pattern of cutaneous blood vessels.

  6. Continuous independent quality control for fetal ultrasound biometry provided by the cumulative summation technique.

    PubMed

    Balsyte, D; Schäffer, L; Burkhardt, T; Wisser, J; Zimmermann, R; Kurmanavicius, J

    2010-04-01

    To apply the cumulative summation (CUSUM) technique for an evaluation of the learning process of sonographic fetal weight estimation at term in combination with the z-scores of biometry determinants and to assess the time of appearance and sources of errors. Learning curve (LC-CUSUM) and double CUSUM charts for systematic error detection based on absolute and signed mean percentage error were generated to retrospectively estimate the longitudinal accuracy of sonographic fetal weight estimation conducted by three trainees and one experienced examiner. For LC-CUSUM analysis an examination was considered to be a failure when there was an absolute error in birth weight estimation >/= 15%. Fetal biometry measurements (head circumference, abdominal circumference (AC) and femur length (FL)) from 227 routine ultrasound scans of one examiner were separately transformed into z-scores and double CUSUM charts were generated to assess the systematic errors for each determinant. The LC-CUSUM charts revealed that different numbers of scans are required for different examiners to achieve competence in estimating birth weight. AC and FL deviated most significantly from expected values (P < 0.05). The double CUSUM charts revealed exact periods of systematic errors in the measurement of biometry determinants, clearly reflecting errors of fetal weight estimation. The use of CUSUM techniques in the analysis of sonographic data allows observation of the development of an examiner's skill and maintenance of competence. The CUSUM technique not only allows the reasons for impaired fetal weight estimation to be revealed but also allows determination of the exact time when inaccurate measurements start to occur. We suggest that CUSUM charts should be implemented in routine clinical practice as a measure of objective quality evaluation of sonographic fetal biometry. Copyright 2009 ISUOG. Published by John Wiley & Sons, Ltd.

  7. Effects of Contact Lens Wear on Biometry Measurements for Intraocular Lens Calculations.

    PubMed

    Meyer, Jay J; Kim, Michelle J; Kim, Terry

    2017-09-21

    To determine the effects of contact lens (CL) wear on biometry measurements for cataract surgery and whether a CL hiatus can reduce the prediction error of intraocular lens (IOL) calculations. Retrospective, interventional case series of eyes that received repeat biometry measurements for IOL calculations after discontinuing hard or soft CLs for at least 14 days. intersession change in axial length, average keratometry, astigmatism, and axis. change in recommended IOL power and toricity, postoperative refraction prediction error. Thirty-two eyes of 16 patients had a mean duration of CL wear (12 hard and 20 soft) of 39.5 years (range, 29-55 years) and mean CL hiatus duration of 25 days (range, 14-56 days). Mean absolute intersession change in axial length was 0.016 mm (range, 0-0.05 mm), average keratometry 0.31 D (range, 0.02-1.01 D), astigmatism 0.41 D (range, 0.01-1.10 D), and axis 6.3° (range, 0-28°). The IOL power predicting the lowest postoperative spherical equivalent changed for 17 of 32 eyes (by 0.5 D for 12 eyes and 1.0 D for five eyes). Recommended IOL toricity changed for nine of 14 eyes (by 0.75 D for six eyes and 1.50 D for three eyes). The median absolute prediction error of IOL calculations was 0.69 D (range, 0.19-2.93 D) before and 0.57 D (range, 0.01-2.82 D) after the CL hiatus (P=0.16). Contact lens wear may affect biometry measurements and subsequent IOL power and toricity selection. For some eyes, repeating biometry measurements after a CL hiatus may improve the accuracy of IOL calculations.

  8. Biometry based ageing of nestling Indian Spotted Owlets ( Athene brama brama)

    PubMed Central

    Pande, Satish; Pawashe, Amit; Mahajan, Mahadeo N.; Mahabal, Anil; Yosef, Reuven; Dahanukar, Neelesh

    2011-01-01

    Abstract Biometric analysis helps in sex differentiation, understanding development and for studies of avian biology such as foraging ecology, evolutionary ecology, and survivorship. We suggest that biometry can also be a reliable, practical and inexpensive tool to determine the age of nestlings in the field by non-invasive methods. As an example we studied the biometry of wing, culmen, talon, tarsus and body mass of nestling southern Indian Spotted Owlets (Athene brama brama). Based on the growth pattern analysis using logistic growth model, discriminant analysis and CHAID (Chi-squared Automatic Interaction Detection) based decision tree, we show that biometry of nestling Spotted Owlets is an easy, reliable and inexpensive method to determine nestling age and to assess growth rate and relative nutritional status. These biometric parameters also allow us to predict their ability to initiate first flight from the nest site. This method is described here for the first time and we postulate that such charts can be devised for other avian species as well, so as to assist conservation biologists and bird rescuers. PMID:22140335

  9. Protective efficacy of the antioxidants vitamin E and Trolox against Microcystis aeruginosa and microcystin-LR in Artemia franciscana nauplii.

    PubMed

    Ruebhart, David R; Wickramasinghe, Wasantha; Cock, Ian E

    2009-01-01

    This study was undertaken to evaluate the protective efficacy of the antioxidants vitamin E and Trolox (a water-soluble vitamin E derivative) against the toxicity of microcystin-LR (MC-LR), Microcystis aeruginosa aqueous extract (CE), and a reference toxin, menadione sodium bisulfite (MSB), in Artemia franciscana nauplii. This was achieved by using the well-established brine shrimp bioassay. The experiment was conducted in 2 stages, with (1) 12-h mortality time course and (2) LC50 determination for 12- and 24-h exposures. Treatments consisted of MC-LR, CE, and MSB alone and with 4-h pretreatments of either vitamin E or Trolox. Sensitivity of A. franciscana nauplii with 24-h LC50 values of 11 (10.1-12.1) microg/ml for MSB and 9.5 (8.8-10.4) microg/ml for MC-LR were in general agreement with values reported for Artemia sp. Both antioxidant pretreatments resulted in significant reductions in mortality of approximately 50% at 9 h postexposure when challenged by either 40 microg/ml MC-LR or 20 microg/ml MSB. In contrast, the antioxidant pretreatments offered little to no protection from CE, suggesting that other uncharacterized bioactive compounds contributed to overall toxicity. The described bioassay is easily accessible, inexpensive, rapid, and complies with animal ethics guidelines of many countries, and thus provides a potential alternative to the mouse bioassay for the initial screening for chemoprotectants against MC-LR toxicity.

  10. Assessment of femur length for fetal biometry in Malaysian pregnant women

    NASA Astrophysics Data System (ADS)

    Ramli, Ramzun Maizan; Adam, Noraina; Jaafar, Mohamad Suhaimi; Rahman, Azhar Abdul; Mustafa, Iskandar Shahrim; Radzi, Yasmin; Nordin, Suriani; Kamarudin, Izyani

    2013-05-01

    The fetal biometry assessment of femur length (FL) was developed in most countries to evaluate the foetus growth. In this study, the FL values for Malaysia population were determined. A prospective study was conducted and a number of 6501 pregnant women were involved with 12372 FL data were collected, performed at antenatal care clinic of Hospital Pulau Pinang, Malaysia. The SPSS software version 17 (regression analysis and paired sample t-test) were used for analysis. The FL values of this study were constructed and rapid FL growth rate in second trimester (2.59 mm/week) than third trimester (1.43 mm/week) was observed. By ethnicity, no significant difference (p ≥ 0.05) was found between the FL values for fetuses of Malay and Indian ethnic's mother (t = -2.042), however these two groups shows significantly (p < 0.05) higher values than those of Chinese ethnic's mother (t = 4.019, 4.083; accordingly). The FL values of Malaysian resulted as significant difference with the common reference FL values from USA and UK, and also with selected Asian populations (India, China, Korea and Japan). As conclusion, it is strong suggested that medical practitioner in Malaysia should avoid in using biometry references based on other population to avoid under- or over-estimation and for accurate assessment of the fetus growth. As this study involved local Malaysian fetuses, therefore the medical practitioner can use the FL values of this study as reference value for fetus biometry assessment in Malaysia.

  11. Fingerprint biometry applications of digital holography and low-coherence interferography.

    PubMed

    Potcoava, Mariana C; Kim, Myung K

    2009-12-01

    We use several holographic and interferographic methods for two- and three-dimensional imaging of fingerprints. Holographic phase microscopy is used to produce images of thin-film patterns left by latent fingerprints. Two or more holographic phase images with different wavelengths are combined for optical phase unwrapping of images of thicker patent prints or a plastic print. Digital interference holography uses scanned wavelengths to synthesize short-coherence interference tomographic images of a plastic print. We also demonstrate light-emitting-diode-based low-coherence interferography for imaging plastic as well as latent prints. These demonstrations point to significant contributions to biometry by the emerging technology of digital holography and interferography.

  12. On the morphology, biometry and biogeography of Lamtopyxiscallistoma (Amoebozoa: Arcellinida).

    PubMed

    Todorov, Milcho

    2015-01-01

    The ultra-structure of the shell and the morphometric variability of soil inhabiting testate amoeba Lamtopyxiscallistoma from Madagascar were studied by using light- and scanning electron microscopy. The biometrical characteristic of the species was made on the basis of 75 specimens measured. In addition to the diameter of the shell, six other shell characters were described biometrically for the first time. The analysis of the variation coefficients shows that the studied population of L.callistoma is comparatively homogeneous and almost all measured characters are weakly to moderate variable (CV less than 10%). Scanning electron microscopy (SEM) studies on the shell ultra-morphology show that it has a smooth apertural surface with a thick layer of porous and fibrous organic cement and a rough dorsal surface composed of bigger and angular pieces of quartz. The shell wall has a thickness of about 5-6 µm and is composed of three layers. Unlike the previously accepted opinion that species is characterized by the presence of four teeth, this study shows that population of L.callistoma from Madagascar is comprised of both, specimens with four teeth and specimens with three teeth, in ratio of about 60% to 40%. Taking into account the restricted geographical distribution, large sizes and characteristic apertural morphology of L.callistoma it is assumed that this species, like some bryophilic 'Nebelas' with circumaustral distribution (e.g. Apoderavas, Alocoderacockayni, Certesellacertesi, Certesellamartiali, etc.), can be used as an example that in free-living microbial eukaryotes 'not everything is everywhere'.

  13. Impact Assessment of Urethral Meatus Morphology and Penile Biometry in Transurethral Prostate and Bladder Surgery

    PubMed Central

    Vieiralves, Rodrigo Ribeiro; Conte, Paulo Henrique Pereira; Felici, Eduardo Medina; Rodrigues, Nádia Cristina Pinheiro; de souza, Tomás Accioly; Sampaio, Francisco J. B.

    2017-01-01

    Objective. To analyze the penile and urethral meatus biometry and its correlation with meatoplasty during endoscopic resections. We also propose a new classification for urethral meatus morphology. Materials and Methods. We prospectively studied 105 patients who underwent prostate and bladder transurethral resections. We performed standardized measurement of penile and urethral meatus biometry followed by penile photo in the front position. The need to perform meatoplasty or dilatation during resectoscope introduction was registered. Data were analyzed comparing the correlation between two groups: without intervention (Group A) and with intervention (Group B). Results. We observed in Group A and Group B, respectively, the average length of urethral meatus of 1.07 cm versus 0.75 cm (p < 0.001) and average width of urethral meatus of 0.59 cm versus 0.38 cm (p < 0.001). Considering the morphology of the urethral meatus, we propose a new classification, in the following groups: (a) typical; (b) slit; (c) point-like; (d) horseshoe; and (e) megameatus. The point-like meatus was the one that most needed intervention, followed by the slit and the typical meatus (p < 0.001). Conclusions. Point-like and slit-shaped urethral meatus, as well as reduced length and width of the urethral meatus, are the determining factors. PMID:28298923

  14. Does 17-α-hydroxyprogesterone caproate affect fetal biometry and birth weight in twin pregnancy?

    PubMed

    Mulder, E J H; Versteegh, E M J; Bloemenkamp, K W M; Lim, A C; Mol, B W J; Bekedam, D J; Kwee, A; Bruinse, H W; Christiaens, G C M L

    2013-09-01

    Increasingly, maternal administration of 17-α-hydroxyprogesterone caproate (17-OHPC) is utilized to prevent preterm birth, but the fetal safety of 17-OHPC is still a matter of concern. This study aimed to assess whether exposure to 17-OHPC during the second and third trimesters of pregnancy affects fetal biometry in twin gestations. This study included a subset of women with a twin pregnancy who had been previously included in a randomized clinical trial comparing the effectiveness of 17-OHPC and placebo on neonatal outcomes and preterm birth rates in multiple pregnancy. In the present study, the individual growth patterns of femur length, head circumference and abdominal circumference were compared between fetuses of women who had been randomized to receive weekly injections of either 17-OHPC (n = 52) or placebo (n = 58) at between 16-20 and 36 weeks' gestation. The three biometric variables assessed developed similarly in fetuses in both the group exposed to 17-OHPC and the placebo group during the second half of pregnancy. Birth weight adjusted for parity and fetal sex was also comparable between groups. The use of 17-OHPC has no adverse effects on fetal biometry and birth weight in twins. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.

  15. Approaches to Teaching Biometry and Epidemiology at Two Veterinary Schools in Germany.

    PubMed

    Zeimet, Ramona; Kreienbrock, Lothar; Doherr, Marcus G

    In a thematically broad and highly condensed curriculum like veterinary medicine, it is essential to pay close attention to the didactic and methodical approaches used to deliver that content. The course topics ideally should be selected for their relevance but also for the target audience and their previous knowledge. The overall objective is to improve the long-term availability of what has been learned. For this reason, an evaluation among lecturers of German-speaking veterinary schools was carried out in 2012 to consider which topics in biometry and epidemiology they found relevant to other subject areas. Based on this survey, two veterinary schools (Berlin and Hannover) developed a structured approach for the introductory course in biometry and epidemiology. By means of an appropriate choice of topics and the use of adequate teaching methods, the quality of the lecture course could be significantly increased. Appropriately communicated learning objectives as well as a high rate of student activity resulted in increased student satisfaction. A certain degree of standardization of teaching approaches and material resulted in a comparison between the study sites and reduced variability in the content delivered at different schools. Part of this was confirmed by the high consistency in the multiple-choice examination results between the study sites. The results highlight the extent to which didactic and methodical restructuring of teaching affects the learning success and satisfaction of students. It can be of interest for other courses in veterinary medicine, human medicine, and biology.

  16. Ultrasound estimation of birth weight in twin pregnancy: comparison of biometry algorithms in the STORK multiple pregnancy cohort.

    PubMed

    Khalil, A; D'Antonio, F; Dias, T; Cooper, D; Thilaganathan, B

    2014-08-01

    The aims of this study were first, to ascertain the accuracy of formulae for ultrasonographic birth-weight estimation in twin compared with singleton pregnancies and second, to assess the accuracy of sonographic examination in the prediction of birth-weight discordance in twin pregnancies. This was a retrospective cohort study including both singleton and twin pregnancies. Routine biometry was recorded and estimated fetal weight (EFW) calculated using 33 different formulae. Only pregnancies that delivered within 48 h of the ultrasound scan were included (4280 singleton and 586 twin fetuses). Differences between the EFW and actual birth weight (ABW) were assessed by percentage error, accuracy in predictions within ± 10% and ± 15% of error and use of the Bland-Altman method. The accuracy of prediction of the different cut-offs of birth-weight discordance in twin pregnancies was also assessed using the area under the receiver-operating characteristics curve (AUC). The overall mean absolute percentage error was ≤ 10% for 25 formulae in singleton pregnancies compared with three formulae in twin pregnancies. The overall predictions within ± 10% and ± 15% of the ABW were 62.2% and 81.5% in singleton and 49.7% and 68.5% in twin pregnancies, respectively. When t e formulae were categorized according to the biometric parameters included, those based on a combination of head, abdomen and femur measurements showed the lowest mean absolute percentage error, in both singleton and twin pregnancies. The predictive accuracy for 25% birth-weight discordance using the Hadlock 2 formula, as assessed by the AUC, was 0.87. Ultrasound estimation of birth weight is less accurate in twin than in singleton pregnancies. Formulae that include a combination of head, abdomen and femur measurements perform best in both singleton and twin pregnancies. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.

  17. Successful Replacement of Artemia salina nauplii with Marine Rotifers (Brachionus plicatilis) in the Diet of Preadult Zebrafish (Danio rerio).

    PubMed

    Lawrence, Christian; James, Althea; Mobley, Scottie

    2015-10-01

    Previously established rearing protocols for zebrafish begin feeding with marine rotifers (Brachionus plicatilis), followed by Artemia nauplii until the fish reach subadult stage, the developmental time point at which they can be most easily transitioned onto a processed diet. However, the inclusion of Artemia is less than ideal, given its fluctuating availability and high costs. We tested whether or not we could replace Artemia with rotifers during our normal rearing sequence and still meet published performance standards for (i) weaning fish onto a processed diet by 25 days postfertilization (dpf) and (ii) successful breeding by 60 dpf. Here, we present the results of trials where wild-type and casper zebrafish were fed exclusively with rotifers (R) or rotifers followed by Artemia (RA) for the first 25 dpf after which point all fish were transitioned to a processed diet (Gemma Micro 300). We measured growth and survival at days 25 and 60, and tested for reproductive capability at 60 dpf. While growth performance was significantly better in the RA groups, we were still able to meet goals for both weaning and generation time in the R groups without compromising survival or sex ratios.

  18. Reducing Vibrio load in Artemia nauplii using antimicrobial photodynamic therapy: a promising strategy to reduce antibiotic application in shrimp larviculture.

    PubMed

    Asok, Aparna; Arshad, Esha; Jasmin, C; Pai, S Somnath; Singh, I S Bright; Mohandas, A; Anas, Abdulaziz

    2012-01-01

    We propose antimicrobial photodynamic therapy (aPDT) as an alternative strategy to reduce the use of antibiotics in shrimp larviculture systems. The growth of a multiple antibiotic resistant Vibrio harveyi strain was effectively controlled by treating the cells with Rose Bengal and photosensitizing for 30 min using a halogen lamp. This resulted in the death of >50% of the cells within the first 10 min of exposure and the 50% reduction in the cell wall integrity after 30 min could be attributed to the destruction of outer membrane protein of V. harveyi by reactive oxygen intermediates produced during the photosensitization. Further, mesocosm experiments with V. harveyi and Artemia nauplii demonstrated that in 30 min, the aPDT could kill 78.9% and 91.2% of heterotrophic bacterial and Vibrio population respectively. In conclusion, the study demonstrated that aPDT with its rapid action and as yet unreported resistance development possibilities could be a propitious strategy to reduce the use of antibiotics in shrimp larviculture systems and thereby, avoid their hazardous effects on human health and the ecosystem at large.

  19. Dispersant Corexit 9500A and chemically dispersed crude oil decreases the growth rates of meroplanktonic barnacle nauplii (Amphibalanus improvisus) and tornaria larvae (Schizocardium sp.).

    PubMed

    Almeda, Rodrigo; Bona, Shawn; Foster, Charles R; Buskey, Edward J

    2014-08-01

    Our knowledge of the lethal and sublethal effects of dispersants and dispersed crude oil on meroplanktonic larvae is limited despite the importance of planktonic larval stages in the life cycle of benthic invertebrates. We determined the effects of Light Louisiana Sweet crude oil, dispersant Corexit 9500A, and dispersant-treated crude oil on the survival and growth rates of nauplii of the barnacle Amphibalanus improvisus and tornaria larvae of the enteropneust Schizocardium sp. Growth rates of barnacle nauplii and tornaria larvae were significantly reduced after exposure to chemically dispersed crude oil and dispersant Corexit 9500A at concentrations commonly found in the water column after dispersant application in crude oil spills. We also found that barnacle nauplii ingested dispersed crude oil, which may have important consequences for the biotransfer of petroleum hydrocarbons through coastal pelagic food webs after a crude oil spill. Therefore, application of chemical dispersants increases the impact of crude oil spills on meroplanktonic larvae, which may affect recruitment and population dynamics of marine benthic invertebrates. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Ocular biometry and determinants of refractive error in a founder population of European ancestry.

    PubMed

    Hilkert, Sarah M; Parness-Yossifon, Reut; Mets-Halgrimson, Rebecca; Mets, Marilyn B

    2017-06-01

    The prevalence of myopia is increasing worldwide. Previous studies have found a positive association between myopia, education, and near activities, while others have noted a negative association with outdoor exposure. This study reports refractive error and biometry in a founder population of European ancestry, the Hutterites, and discusses risk factors contributing to myopia. Cross-sectional study, including complete eye exams with retinoscopy and biometry. 939 study participants, ages 6 to 89, were examined. Females were significantly more myopic than males (SE -0.87 ± 2.07 and -0.40 ± 1.49 in females and males, respectively, p < 0.0001). Males had significantly longer axial lengths. Females had steeper corneas. This is the first epidemiological report of refractive error among the Hutterites. As a genetically isolated population with a communal lifestyle, the Hutterites present a unique opportunity to study risk factors for myopia. Hutterite females are more myopic than males, a finding which has only been reported in a few other populations. Hutterite children complete compulsory education through the 8th grade, after which women and men assume gender-specific occupational tasks. Men often work outside on the farm, while women engage in more domestic activities inside. These occupational differences likely contribute to the increased myopia comparing females to males, and their uniform lifestyle reduces the impact of potential confounding factors, such as education and income. The Hutterites are more myopic than most other North American and European populations. Greater time spent doing near work and less time spent outdoors likely explain the increased myopia comparing females to males.

  1. Costs of cloud computing for a biometry department. A case study.

    PubMed

    Knaus, J; Hieke, S; Binder, H; Schwarzer, G

    2013-01-01

    "Cloud" computing providers, such as the Amazon Web Services (AWS), offer stable and scalable computational resources based on hardware virtualization, with short, usually hourly, billing periods. The idea of pay-as-you-use seems appealing for biometry research units which have only limited access to university or corporate data center resources or grids. This case study compares the costs of an existing heterogeneous on-site hardware pool in a Medical Biometry and Statistics department to a comparable AWS offer. The "total cost of ownership", including all direct costs, is determined for the on-site hardware, and hourly prices are derived, based on actual system utilization during the year 2011. Indirect costs, which are difficult to quantify are not included in this comparison, but nevertheless some rough guidance from our experience is given. To indicate the scale of costs for a methodological research project, a simulation study of a permutation-based statistical approach is performed using AWS and on-site hardware. In the presented case, with a system utilization of 25-30 percent and 3-5-year amortization, on-site hardware can result in smaller costs, compared to hourly rental in the cloud dependent on the instance chosen. Renting cloud instances with sufficient main memory is a deciding factor in this comparison. Costs for on-site hardware may vary, depending on the specific infrastructure at a research unit, but have only moderate impact on the overall comparison and subsequent decision for obtaining affordable scientific computing resources. Overall utilization has a much stronger impact as it determines the actual computing hours needed per year. Taking this into ac count, cloud computing might still be a viable option for projects with limited maturity, or as a supplement for short peaks in demand.

  2. Automatic biometry of the anterior segment during accommodation imaged by optical coherence tomography.

    PubMed

    Zhu, Dexi; Shao, Yilei; Leng, Lin; Xu, Zhe; Wang, Jianhua; Lu, Fan; Shen, Meixiao

    2014-07-01

    To test accuracy and repeatability of a software algorithm that performs automatic biometry of the anterior segment of the human eye imaged with long scan depth optical coherence tomography (OCT). The ocular anterior segment imaging was performed with custom-built long scan depth OCT. An automatic software algorithm including boundary segmentation, image registration, and optical correction was developed for fast and reliable biometric measurements based on the OCT images. The boundary segmentation algorithm mainly used the gradient information of images and applied the shortest path search based on the dynamic programming to optimize the edge finding. The automatic algorithm was validated by comparison of the biometric dimensions between automatic and manual measurements and repeatability study. Biometric dimensions of the anterior segment, including central corneal thickness, anterior chamber depth, pupil diameter, crystalline lens thickness, and radii of curvature of the anterior and posterior surfaces of lens, were obtained by the automatic algorithm successfully. There were no significant differences between the automatic and manual measurements for all biometric dimensions. The intraclass correlation coefficients (ICC) of agreement between automatic and manual measurements ranged from 0.85 to 0.98. The coefficients of repeatability and ICC for all automatic dimensions were satisfactory (1.1%-6.1% and 0.663-0.990, respectively). The high accuracy, good repeatability, and fast execution speed for automatic measurement of the anterior segment dimensions on the OCT images were demonstrated. The application of this automatic biometry is promising for investigating dynamic changes of human anterior segment during accommodation in real time.

  3. Ocular biometry in occludable angles and angle closure glaucoma: a population based survey.

    PubMed

    George, R; Paul, P G; Baskaran, M; Ramesh, S Ve; Raju, P; Arvind, H; McCarty, C; Vijaya, L

    2003-04-01

    To compare ocular biometric values in a population based sample of eyes with occludable angles, angle closure glaucoma, and normal subjects. 2850 subjects from a population based glaucoma prevalence study underwent complete ocular examination including indentation gonioscopy. Ocular biometry was performed in all subjects classified to have occludable angles (n = 143); angle closure glaucoma (n = 22), and a random subgroup of 419 normal subjects. Ocular biometry readings between the groups were compared and statistically analysed using "t," "z," and Mann-Whitney U tests. The mean age among subjects with occludable angles (54.43 (SD 9.53) years) and angle closure glaucoma (57.45 (8.5) years) was significantly higher (p<0.001) than normal subjects (49.95 (9.95) years). Axial length was shorter (p<0.001) in the occludable angle group (22.07 (0.69) mm) compared to the normal group (22.76 (0.78) mm). Anterior chamber depth (ACD) was shallower (p<0.001) among subjects with occludable angles (2.53 (0.26) mm) than normal subjects (3.00 (0.30) mm). Lens thickness (LT) was greater (p<0.001) in people with occludable angles (4.40 (0.53) mm) compared to normal subjects (4.31 (0.31) mm). No significant difference was noted in axial length, ACD (p = 0.451), and LT (p = 0.302) between angle closure glaucoma and occludable eyes. South Indian eyes with angle closure glaucoma and occludable angles seem to have significantly shorter axial lengths, shallower anterior chambers and greater lens thickness compared to the normal group.

  4. An observational study on changes in biometry and generation time of Odontophora villoti (Nematoda, Axonolaimidae) related to petroleum pollution in Bizerte bay, Tunisia.

    PubMed

    Boufahja, Fehmi; Hedfi, Amor; Essid, Naceur; Aïssa, Patricia; Mahmoudi, Ezzeddine; Beyrem, Hamouda

    2012-03-01

    We conducted a yearly polluted-reference sampling to assess the effects of petroleum pollution on life cycle characteristics of the meiobenthic nematode Odontophora villoti. Samples were taken every 15 days between 26 November 2004 and 25 November 2005 from two beaches of Bizerte bay (Tunisia), Rimel and Tunisian Refining Industries Company (TRIC). The latter site is located in front of the "Tunisian Refining Industries Company" runoff. When compared to the reference site, the mean body dimensions of O. villoti from the impacted site were significantly lower. The small size of affected nematodes was represented both by the length and width as a function of the life stage. It was also established that changes in lengths of body parts during molts were different between the two study sites. The low availability of oxygen from April to August seems to prevent the formation of embryos of O. villoti. Thus, two annual reproductive cycles with different durations were observed in Rimel and TRIC. Under stress, juvenile phase and egg production were generally shorter. Globally, the impact of petroleum pollution on O. villoti was expressed by a short egg-to-egg development time. Our study assessed the usefulness of life cycle characteristics (biometry and life stage durations) of O. villoti in biomonitoring, and the results are generally consistent suggesting that this species may be considered as an efficient bioindicator.

  5. Correlation between pre-pregnancy body mass index and maternal visceral adiposity with fetal biometry during the second trimester.

    PubMed

    Lopes, Karina R M; Souza, Alex Sandro R; Figueiroa, José N; Alves, João Guilherme B

    2017-08-01

    To determine the correlation between pre-pregnancy body mass index (BMI) and maternal visceral adiposity with fetal biometry during the second trimester. A cross-sectional observational study was conducted among pregnant women who received prenatal care at a center in Recife, Brazil, between October 3, 2011, and September 27, 2013. Pre-pregnancy BMI was determined at the first prenatal care visit. Maternal visceral adiposity and fetal biometry were measured at the same ultrasonography session. The associations between maternal and fetal variables were evaluated using the Pearson correlation coefficient (R). The Student t test was used to test the null hypothesis of adjusted correlation coefficients. Overall, 740 women were included. No correlation was found between pre-pregnancy BMI and any of the fetal biometric variables assessed. By contrast, maternal visceral adiposity positively correlated with fetal abdominal circumference (R=0.529), estimated fetal weight (R=0.524), head circumference (R=0.521), femur length (R=0.521), and biparietal diameter (R=0.524; P<0.001 for all fetal variables). These findings remained statistically significant after controlling for pregnancy length. Maternal visceral adiposity, but not pre-pregnancy BMI, positively correlated with fetal biometry during the second trimester. © 2017 International Federation of Gynecology and Obstetrics.

  6. Discordance in fetal biometry and Doppler are independent predictors of the risk of perinatal loss in twin pregnancies.

    PubMed

    Khalil, Asma A; Khan, Naila; Bowe, Sophie; Familiari, Alessandra; Papageorghiou, Aris; Bhide, Amar; Thilaganathan, Basky

    2015-08-01

    Impaired fetal growth might be better evaluated in twin pregnancies by assessing the intertwin discordance rather than the individual fetal size. The aim of this study was to investigate the prediction of perinatal loss in twin pregnancy using discordance in fetal biometry and Doppler. This was a retrospective cohort study in a tertiary referral center. The estimated fetal weight (EFW), umbilical artery (UA) pulsatility index (PI), middle cerebral artery (MCA) PI, cerebroplacental ratio (CPR), and their discordance recorded at the last ultrasound assessment before delivery or demise of one or both fetuses were converted into centiles or multiples of the median (MoM). The discordance was calculated as the larger value-smaller value/larger value. A logistic regression analysis was performed to identify, and adjust for, potential confounders. The predictive accuracy was assessed using receiver-operating characteristic curve analysis. The analysis included 620 (464 dichorionic diamniotic and 156 monochorionic diamniotic) twin pregnancies (1240 fetuses). Perinatal loss of one or both fetuses complicated 16 pregnancies (2.6%). The combination of EFW discordance and CPR discordance had the best predictive performance (area under the curve, 0.96; 95% confidence interval, 0.92-1.00) for perinatal mortality. The detection rate, false-positive rate, positive likelihood ratio, and negative likelihood ratio were 87.5%, 6.7%, 13.08, and 0.13, respectively. The EFW centile, EFW below the 10th centile (small for gestational age), UA PI discordance, MCA PI discordance, and MCA PI MoM were significantly associated with the risk of perinatal loss on univariate analysis, but these associations became nonsignificant after adjusting for other confounders (P = .097, P = .090, P = .687, P = .360, and P = .074, respectively). The UA PI MoM, CPR MoM, EFW discordance, and CPR discordance were all independent predictors of the risk of perinatal loss, even after adjusting for potential

  7. A data assimilation framework for constraining upscaled cropland carbon flux seasonality and biometry with MODIS

    NASA Astrophysics Data System (ADS)

    Sus, O.; Heuer, M. W.; Meyers, T. P.; Williams, M.

    2013-04-01

    Agroecosystem models are strongly dependent on information on land management patterns for regional applications. Land management practices play a major role in determining global yield variability, and add an anthropogenic signal to the observed seasonality of atmospheric CO2 concentrations. However, there is still little knowledge on spatial and temporal variability of important farmland activities such as crop sowing dates, and thus these remain rather crudely approximated within carbon cycle studies. In this study, we present a framework allowing for spatio-temporally resolved simulation of cropland carbon fluxes under observational constraints on land management and canopy greenness. We apply data assimilation methodology in order to explicitly account for information on sowing dates and model leaf area index. MODIS 250 m vegetation index data were assimilated both in batch-calibration for sowing date estimation and sequentially for improved model state estimation, using the ensemble Kalman filter (EnKF), into a crop carbon mass balance model (SPAc). In doing so, we are able to quantify the multiannual (2000-2006) regional carbon flux and biometry seasonality of maize-soybean crop rotations surrounding the Bondville Ameriflux eddy covariance site, averaged over 104 pixel locations within the wider area. (1) Validation at the Bondville site shows that growing season C cycling is simulated accurately with MODIS-derived sowing dates, and we expect that this framework allows for accurate simulations of C cycling at locations for which ground-truth data are not available. Thus, this framework enables modellers to simulate current (i.e. last 10 yr) carbon cycling of major agricultural regions. Averaged over the 104 field patches analysed, relative spatial variability for biometry and net ecosystem exchange ranges from ∼7% to ∼18%. The annual sign of net biome productivity is not significantly different from carbon neutrality. (2) Moreover, observing carbon

  8. A data assimilation framework for constraining upscaled cropland carbon flux seasonality and biometry with MODIS

    NASA Astrophysics Data System (ADS)

    Sus, O.; Heuer, M. W.; Meyers, T. P.; Williams, M.

    2012-08-01

    Agroecosystem models are strongly dependent on information on land management patterns for regional applications. Land management practices play a major role in determining global yield variability, and add an anthropogenic signal to the observed seasonality of atmospheric CO2 concentrations. However, there is still little knowledge on spatial and temporal variability of important farmland activities such as crop sowing dates, and thus these remain rather crudely approximated within carbon cycle studies. In this study, we present a framework allowing for spatio-temporally resolved simulation of cropland carbon fluxes under observational constraints on land management and canopy greenness. We apply a data assimilation methodology in order to explicitly account for information on sowing dates and model leaf area index. MODIS 250 m vegetation index data were assimilated both variationally (for sowing date estimation) and sequentially (for improved model state estimation, using the Ensemble Kalman Filter) into a crop carbon mass balance model (SPAc). In doing so, we are able to accurately quantify the multiannual (2000-2006) regional carbon flux and biometry seasonality of maize-soybean crop rotations surrounding the Bondville Ameriflux eddy covariance site, averaged over 104 pixel locations within the wider area. (1) From Bondville site results we deduce that MODIS-derived sowing dates allow for accurate simulations of growing season carbon cycling at locations for which such ground-truth data are not available. Thus, this framework enables modellers to simulate current (i.e. last 10 yr) carbon cycling of major agricultural regions. Averaged over the 104 field patches analysed, relative spatial variability for biometry and net ecosystem exchange ranges from ~7 % to ~18 %. The annual sign of net biome productivity is not significantly different from carbon neutrality. (2) Moreover, observing carbon cycling at one single field with its individual sowing pattern is not

  9. Biometry, keratometry, and calculation of intraocular lens power for the bald eagle (Haliaeetus leucocephalus).

    PubMed

    Kuhn, Sonia E; Hendrix, Diane V H; Jones, Michael P; Ward, Daniel A; Baine, Katherine H; Franklin, Stephen R

    2015-01-01

    To document intraocular measurements and predict intraocular lens (IOL) power specific to the bald eagle. Eleven adult, captive bald eagles. Axial globe length (AGL), anterior chamber depth (ACD), crystalline lens thickness (CLT), and the distance from the cornea to the posterior lens capsule (CPLC) were measured in eight adult bald eagles using B-mode with vector A-mode ultrasound. Keratometry was done on four eagles. Two estimates for postoperative anterior chamber depth (PACD) were obtained from four aphakic eyes from three eagles by measuring from the apex of the anterior cornea to the center of an imaginary line that would connect the remaining edges of the anterior lens capsule across the capsulorhexis (PACD1) and from the apex of the anterior cornea to halfway between the anterior and posterior lens capsule (PACD2). IOL strength was predicted using the Colenbrander, Binkhorst, and Fyodorov theoretical formulas. Mean ± SD biometry for phakic eyes was AGL = 26.57 ± 0.45 mm, ACD = 4.45 ± 0.18 mm, CLT = 5.49 ± 0.14 mm, and CPLC = 10.00 ± 0.33 mm. Mean predicted PACD1 was 6.1 ± 0.66 mm, and PACD2 was 6.4 ± 0.70 mm. Mean horizontal and vertical corneal refractive power was 39.91 ± 0.43 diopters (D) and 40.02 ± 0.08 D, respectively. Calculated IOL power ranged from +16.4 to 17.4 D. Calculations using ultrasonographic biometry, keratometry, and theoretical IOL formulas suggest that the strength of an IOL necessary to return an aphakic bald eagle to emmetropia is between +16.4 and +17.4 D. © 2013 American College of Veterinary Ophthalmologists.

  10. Pelvic floor biometry in Chinese primiparous women 1 year after delivery: a prospective observational study.

    PubMed

    Chan, S S C; Cheung, R Y K; Yiu, K W; Lee, L L; Chung, T K H

    2014-04-01

    To evaluate pelvic floor biometry in Chinese women 1 year following childbirth and to explore factors that affect it. Translabial ultrasound examination was performed at rest, on Valsalva maneuver (VM) and on pelvic floor muscle contraction (PFMC) in the first, second and third trimesters of pregnancy and at 8 weeks, 6 months and 12 months after delivery in a cohort of women delivering at term their first child. Offline analysis was undertaken to measure the position of the bladder neck, cervix, anorectal junction and hiatal dimensions at each posture and at each visit, and to detect levator ani muscle (LAM) injury on PFMC 8 weeks and 12 months after delivery. Results were analyzed according to mode of delivery. We recruited 442 women, of whom 328 (74.2%) completed the study; there was LAM injury in 48 women at 8 weeks and in only 38 women at 12 months. When comparing first-trimester biometry to that at 12 months after delivery, the bladder neck was more distal on VM and bladder neck displacement was increased, and the cervix was lower at rest and on VM in the vaginal delivery group. In the Cesarean section group, bladder neck and anorectal junction were more distal on VM, the cervix was lower at rest, on VM and on PFMC, and the hiatal area was increased on VM. There was a greater increase in hiatal area after vaginal delivery. Overall, 34.8% had irreversible hiatal distension (> 20% increase in hiatal area after delivery as compared to first trimester). LAM injury was significantly associated with irreversible hiatal distension (odds ratios, 5.2-9.5 at different postures). Pregnancy beyond 35 weeks of gestation has an effect on the pelvic floor of Chinese women, irrespective of mode of delivery. The pelvic organs remain more mobile after delivery when compared to in the first trimester, and there is no clear difference between the findings observed following vaginal delivery or Cesarean section, except in hiatal distension, which is greater after vaginal delivery

  11. Repeatability and comparability of anterior segment biometry obtained by the Sirius and the Pentacam analyzers.

    PubMed

    De la Parra-Colín, Paola; Garza-León, Manuel; Barrientos-Gutierrez, Tonatiuh

    2014-02-01

    To assess the repeatability and comparability of six anterior segment biometry parameters obtained with a novel Scheimpflug camera with a Placido disc topographer (Sirius) and slit-scanning tomography with a Scheimpflug camera (Pentacam), in a sample of 16 unoperated eyes of healthy subjects. The anterior segment was analyzed by a single examiner using the Sirius and the Pentacam analyzers. Mean simulated keratometry (Sim K), flat and steep axis keratometry (K f and K s ), central and thinnest corneal thicknesses (CCT and TCT), and anterior chamber depth (ACD) measurements were evaluated. Repeatability of three sets of measurements from each device was assessed using the coefficient of variation (CV), within-subject standard deviation, and intraclass correlation coefficient (ICC). Bonferroni-adjusted t-tests, and Bland and Altman plots were used to establish agreement between devices. For both devices the CV of repeated measurements was <0.79 %. The ICC was >0.95 in all measurements except for Sirius K s (ICC = 0.869). For all parameters evaluated, the Pentacam systematically yielded higher values, although differences were statistically significant in only three parameters-0.31 diopters for K s , 10.1 μm for CCT and 12.4 μm for TCT. In the assessment of normal corneas both devices showed overall high repeatability. Although good agreement was found in three parameters (Sim K, K f and ACD) these devices do not seem to be interchangeable for pachymetric determination.

  12. Longitudinal z Score Distribution in Sonographic Fetal Biometry: Influence of Examiner and Experience.

    PubMed

    Faschingbauer, Florian; Heimrich, Jutta; Raabe, Eva; Kehl, Sven; Schneider, Michael; Schmid, Matthias; Beckmann, Matthias W; Schild, Ralf L; Mayr, Andreas

    2017-05-01

    To analyze the influence of examiners and their experience on the quality of biometric measurements via the evolution of z scores in a longitudinal multicenter study. This retrospective study included 4607 sonographic fetal biometric examinations performed by 18 examiners at the beginning of their sonography training. To analyze the quality of biometric measurements, z scores comparing the individual measurements with the expected values from a standard population were computed. To investigate the effect of examiners and their experience, we applied a multivariable regression analysis via generalized additive mixed models. Mean z scores for biparietal diameter, abdominal circumference, and femur length were statistically different from the expected value of 0 (P < .001); no significant differences were found for head circumference measurements. Regression analyses showed a significant effect of the number of examinations on the distribution of z scores for each type of measurement. This effect yielded z score values close to the expected value of 0 at 100 to 200 examinations for all biometric measurements, indicating good consistency with the distribution of values in the reference population. Near the end of the study period, an increasing tendency toward either overestimation (head circumference) or underestimation (biparietal diameter, abdominal circumference, and femur length) was observed. A longitudinal analysis of the z score distribution for quality control of biometry is feasible. A prospective and automatized use of this technique could help identify potential systematic errors and therefore improve the detection rate for high-risk pregnancies. © 2017 by the American Institute of Ultrasound in Medicine.

  13. [Reference tables of fetal biometry for people in the West of Mexico].

    PubMed

    Barrios-Prieto, Ernesto; Martínez-Ceccopieri, David Alejandro; Torres-Mercado, Arturo Javier; Fajardo-Dueñas, Sergio; Panduro-Barón, J Guadalupe

    2013-06-01

    Fetal growth has geographical and ethnic variations. Fetuses from different parts of the world show also different growth patterns. Using individualized fetal biometry charts increase the detection of fetuses at risk, probably due to a better identification of intrauterine growth restriction; moreover they correlate better with anthropometric parameters than conventional curves. To determine and describe the reference curves of fetal biometric parameters in the population of western Mexico. Cross-sectional and descriptive study, conducted between September 2006 and December 2011 in patients admitted to the Maternal Fetal Medicine Unit at Civil Hospital of Guadalajara Dr. Juan I. Menchaca. We included 1,833 patients with single pregnancies without fetal or maternal pathology with established gestational age by the date of the last menstrual period and confirmed by first trimester ultrasound. Percentils 3, 5, 10, 50 and 95 were calculated for every biometric variable. The largest growth rate was seen between 26 to 38 weeks of gestation and a progressive flattening of the growth curve was observed from the 38th week of gestation. The percentiles of fetal biometric parameters in the population of western Mexico are lower than those reported in previously published literature.

  14. Simultaneous refraction measurement and OCT axial biometry of the eye during accommodation (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    De Freitas, Carolina; Hernandez, Victor M.; Ruggeri, Marco; Durkee, Heather A.; Williams, Siobhan; Gregori, Giovanni; Ho, Arthur; Manns, Fabrice; Parel, Jean-Marie

    2016-03-01

    The purpose of this project is to design and evaluate a system that will enable objective assessment of the optical accommodative response in real-time while acquiring axial biometric information. The system combines three sub-systems which were integrated and mounted on a joystick x-y-z adjustable modified slit-lamp base to facilitate alignment and data acquisition: (1) a Shack-Hartmann wavefront sensor for dynamic refraction measurement, provided software calculates sphere, cylinder and axis values, (2) an extended-depth Optical Coherence Tomography (OCT) system using an optical switch records high-resolution cross-sectional images across the length of the eye, from which, dynamic axial biometry (corneal thickness, anterior chamber depth, crystalline lens thickness and vitreous depth) can be extracted, and (3) a modified dual-channel accommodation stimulus unit based on the Badal optometer for providing a step change in accommodative stimulus. The prototypal system is capable of taking simultaneous measurements of both the optical and the mechanical response of lens accommodation. These measurements can provide insight into correlating changes in lens shape with changes in lens power and ocular refraction and ultimately provide a more comprehensive understanding of accommodation, presbyopia and an objective assessment of presbyopia correction techniques.

  15. Green synthesis of gold nanoparticles using a cheap Sphaeranthus indicus extract: Impact on plant cells and the aquatic crustacean Artemia nauplii.

    PubMed

    Balalakshmi, Chinnasamy; Gopinath, Kasi; Govindarajan, Marimuthu; Lokesh, Ravi; Arumugam, Ayyakannu; Alharbi, Naiyf S; Kadaikunnan, Shine; Khaled, Jamal M; Benelli, Giovanni

    2017-08-01

    The impact of green-fabricated gold nanoparticles on plant cells and non-target aquatic species is scarcely studied. In this research, we reported an environment friendly technique for the synthesis of gold nanoparticles (Au NPs) using the Sphaeranthus indicus leaf extract. The formation of the metal NPs was characterized by UV-Visible and FT-IR spectroscopy, XRD, SEM and TEM analyses. The UV-Visible spectra of Au NPs showed a surface plasmon resonance peak at 531nm. FT-IR analysis indicated functional bio-molecules associated with Au NPs formation. The crystalline nature of Au nanoparticles was confirmed by their XRD diffraction pattern. TEM revealed the spherical shape with a mean particle size of 25nm. Au NPs was tested at 0, 1, 3, 5, 7 and 10% doses in mitotic cell division assays, pollen germination experiments, and in vivo toxicity trials against the aquatic crustacean Artemia nauplii. Au NPs did not show any toxic effects on plant cells and aquatic invertebrates. Notably, Au NPs promoted mitotic cell division in Allium cepa root tip cells and germination of Gloriosa superba pollen grains. Au NPs showed no mortality on A. nauplii, all the tested animals showed 100% survivability. Therefore, these Au NPs have potential applications in the development of pollen germination media and plant tissue culture. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Feeding behaviour of the nauplii of the marine calanoid copepod Paracartia grani Sars: Functional response, prey size spectrum, and effects of the presence of alternative prey

    PubMed Central

    Saiz, Enric

    2017-01-01

    Laboratory feeding experiments were conducted to study the functional response and prey size spectrum of the young naupliar stages of the calanoid copepod Paracartia grani Sars. Experiments were conducted on a range of microalgal prey of varying sizes and motility patterns. Significant feeding was found in all prey of a size range of 4.5–19.8 μm, with Holling type III functional responses observed for most prey types. The highest clearance rates occurred when nauplii fed on the dinoflagellate Heterocapsa sp. and the diatom Thalassiosira weissflogii (respectively, 0.61 and 0.70 mL ind-1 d-1), suggesting an optimal prey:predator ratio of 0.09. Additional experiments were conducted to examine the effects of the presence of alternative prey (either Heterocapsa sp. or Gymnodinium litoralis) on the functional response to the haptophyte Isochrysis galbana. In the bialgal mixtures, clearance and ingestion rates of I. galbana along the range of the functional response were significantly reduced as a result of selectivity towards the larger, alternative prey. Paradoxically, relatively large prey trigger a perception response in the nauplii, but most likely such prey cannot be completely ingested and a certain degree of sloppy feeding may occur. Our results are further evidence of the complex prey-specific feeding interactions that are likely to occur in natural assemblages with several available prey types. PMID:28257517

  17. Effect of pupillary dilation on Haigis formula-calculated intraocular lens power measurement by using optical biometry

    PubMed Central

    Khambhiphant, Bharkbhum; Sasiwilasagorn, Suganlaya; Chatbunchachai, Nattida; Pongpirul, Krit

    2016-01-01

    Purpose The purpose of this study was to evaluate the effect of pupillary dilation on the Haigis formula-calculated intraocular lens (IOL) power and ocular biometry measurements by using IOLMaster®. Methods A prospective study was performed for biometry measurements of 373 eyes of 192 healthy subjects using the IOLMaster at the outpatient department of King Chulalongkorn Memorial Hospital from February 2013 to July 2013. The axial length (AL), anterior chamber depth (ACD), keratometry (K), and IOL power were measured before and after 1% tropicamide eye drop instillation. The Haigis formula was used in the IOL power calculation with the predicted target to emmetropia. Each parameter was compared by a paired t-test prior to and after pupillary dilation. Bland–Altman plots were also used to determine the agreement between each parameter. Results The mean age of the subjects was 53.74±14.41 years (range 18–93 years). No differences in AL (P=0.03), steepest K (P=0.42), and flattest K (P=0.41) were obtained from the IOLMaster after pupillary dilation. However, ACD and IOL power were significantly different postdilation (P<0.01 and P<0.01, respectively). In ACD and IOL power measurements, the concordance rates were 93.03% and 97.05% within 95% limits of agreement (−0.48 to 0.26 mm and −1.09 to 0.88 D, respectively) in the Bland–Altman plots. Conclusion Biometry measurements in the cycloplegic stage should be considered in the IOL formulas that use parameters other than AL and K. PMID:27555746

  18. Longitudinal changes in fetal biometry and cerebroplacental hemodynamics in fetuses with congenital heart disease.

    PubMed

    Ruiz, A; Cruz-Lemini, M; Masoller, N; Sanz-Cortés, M; Ferrer, Q; Ribera, I; Martínez, J M; Crispi, F; Arévalo, S; Gómez, O; Pérez-Hoyos, S; Carreras, E; Gratacós, E; Llurba, E

    2017-03-01

    To determine the longitudinal behavior of fetal biometric measures and cerebroplacental hemodynamics throughout gestation in fetuses with congenital heart disease (CHD). Fetal biometry and Doppler hemodynamics (uterine artery (UtA), umbilical artery (UA) and fetal middle cerebral artery (MCA)) were measured serially in a cohort of consecutive fetuses diagnosed with CHD. Evaluations were made at various time points, from diagnosis (20-25 weeks) to delivery, with at least two measurements per fetus that were at least 2 weeks apart. Fetuses were classified into three groups according to the pattern of blood supply to the brain (placental vs systemic) that would be expected on the basis of the type of CHD. All parameters were transformed into Z-scores. A linear mixed model to analyze repeated measurements was constructed for each parameter to assess its behavior throughout gestation. Four hundred and forty-four ultrasound examinations were performed in 119 CHD fetuses, with a median of two measurements per fetus. The fetuses presented a small head at diagnosis (biparietal diameter (BPD) Z-score, -1.32 ± 0.99; head circumference (HC) Z-score, -0.79 ± 1.02), which remained small throughout gestation. UtA and UA pulsatility indices (PI) showed a significant increase towards the end of pregnancy, whereas no significant changes were observed in MCA-PI or cerebroplacental ratio (CPR) with gestational age. Both MCA and CPR presented significant differences in longitudinal behavior between CHD groups, while BPD and HC did not. CHD fetuses have a relatively small head from the second trimester of pregnancy, regardless of the type of CHD anomaly, and increasing resistance in the UtA and UA as pregnancy progresses, suggestive of increasing degree of placental impairment. Our findings indicate the early onset of mechanisms that could lead to poorer neurodevelopment later in life. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2016 ISUOG. Published by

  19. Automated feature extraction for retinal vascular biometry in zebrafish using OCT angiography

    NASA Astrophysics Data System (ADS)

    Bozic, Ivan; Rao, Gopikrishna M.; Desai, Vineet; Tao, Yuankai K.

    2017-02-01

    Zebrafish have been identified as an ideal model for angiogenesis because of anatomical and functional similarities with other vertebrates. The scale and complexity of zebrafish assays are limited by the need to manually treat and serially screen animals, and recent technological advances have focused on automation and improving throughput. Here, we use optical coherence tomography (OCT) and OCT angiography (OCT-A) to perform noninvasive, in vivo imaging of retinal vasculature in zebrafish. OCT-A summed voxel projections were low pass filtered and skeletonized to create an en face vascular map prior to connectivity analysis. Vascular segmentation was referenced to the optic nerve head (ONH), which was identified by automatically segmenting the retinal pigment epithelium boundary on the OCT structural volume. The first vessel branch generation was identified as skeleton segments with branch points closest to the ONH, and subsequent generations were found iteratively by expanding the search space outwards from the ONH. Biometric parameters, including length, curvature, and branch angle of each vessel segment were calculated and grouped by branch generation. Despite manual handling and alignment of each animal over multiple time points, we observe distinct qualitative patterns that enable unique identification of each eye from individual animals. We believe this OCT-based retinal biometry method can be applied for automated animal identification and handling in high-throughput organism-level pharmacological assays and genetic screens. In addition, these extracted features may enable high-resolution quantification of longitudinal vascular changes as a method for studying zebrafish models of retinal neovascularization and vascular remodeling.

  20. Pelvic floor muscle biometry and pelvic organ mobility in East Asian and Caucasian nulliparae.

    PubMed

    Cheung, R Y K; Shek, K L; Chan, S S C; Chung, T K H; Dietz, H P

    2015-05-01

    To compare the differences in levator ani muscle biometry and hiatal dimensions between pregnant nulliparous Caucasian and East Asian women. Offline analysis of three/four-dimensional ultrasound volume data obtained from two groups of pregnant nulliparous women, Caucasian and East Asian, was performed. Volume acquisition was performed in the late third trimester using the same method in both groups, in the context of two prospective observational studies with identical entry criteria. Pelvic organ descent and levator hiatal dimensions were assessed using the volumes acquired on Valsalva maneuver, and pubovisceral muscle thickness was measured from the volumes obtained on pelvic floor muscle contraction (PFMC). Datasets of 200 East Asian and 168 Caucasian women were analyzed. Compared with Caucasian women, East Asian women had a significantly lower body mass index. All indices of pelvic organ descent were significantly higher in the Caucasian group than in the East Asian group. The difference, expressed as a percentage, in levator hiatal area on both Valsalva maneuver and PFMC was markedly greater in Caucasian (32% vs. 19%; P < 0.001) than in East Asian (24% vs. 20%; P = 0.01) women. After controlling for potential confounders using multivariate regression analysis, racial origin remained the only significant factor associated with differences in pelvic organ descent and hiatal dimensions. The thickness and area of pubovisceral muscle were significantly higher in the East Asian group. Pregnant women of East Asian racial origin have a thicker pubovisceral muscle, smaller hiatus and less mobility of pelvic organs than do pregnant Caucasian women. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

  1. Meta-analysis of optical low-coherence reflectometry versus partial coherence interferometry biometry

    PubMed Central

    Huang, Jinhai; McAlinden, Colm; Huang, Yingying; Wen, Daizong; Savini, Giacomo; Tu, Ruixue; Wang, Qinmei

    2017-01-01

    A meta-analysis to compare ocular biometry measured by optical low-coherence reflectometry (Lenstar LS900; Haag Streit) and partial coherence interferometry (the IOLMaster optical biometer; Carl Zeiss Meditec). A systematic literature search was conducted for articles published up to August 6th 2015 in the Cochrane Library, PubMed, Medline, Embase, China Knowledge Resource Integrated Database and Wanfang Data. A total of 18 studies involving 1921 eyes were included. There were no statistically significant differences in axial length (mean difference [MD] 0 mm; 95% confidence interval (CI) −0.08 to 0.08 mm; p = 0.92), anterior chamber depth (MD 0.02 mm; 95% CI −0.07 to 0.10 mm; p = 0.67), flat keratometry (MD −0.05 D; 95% CI −0.16 to 0.06 D; p = 0.39), steep keratometry (MD −0.09 D; 95% CI −0.20 to 0.03 D; p = 0.13), and mean keratometry (MD −0.15 D; 95% CI −0.30 to 0.00 D; p = 0.05). The white to white distance showed a statistically significant difference (MD −0.14 mm; 95% CI −0.25 to −0.02 mm; p = 0.02). In conclusion, there was no difference in the comparison of AL, ACD and keratometry readings between the Lenstar and IOLMaster. However the WTW distance indicated a statistically significant difference between the two devices. Apart from the WTW distance, measurements for AL, ACD and keratometry readings may be used interchangeability with both devices. PMID:28233846

  2. B-mode ultrasonography biometry of the Amazon Parrot (Amazona aestiva) eye.

    PubMed

    Lehmkuhl, Ricardo C; Almeida, Mariana F; Mamprim, Maria J; Vulcano, Luiz C

    2010-09-01

    Ultrasonographic evaluation of the eye is a relatively recent addition to routine ophthalmic diagnostics in small animal ophthalmology. Some parameters for ophthalmic biometry have been established. There are few studies in clinical avian ophthalmology that describe ultrasound images of eye in some nocturnal avian species and in other birds that do not belong to the Brazilian fauna, but the psittacine family is not represented. The purpose of this study was to describe the following measurements: the distances between cornea and anterior lens capsule (D1) between the anterior and posterior lens capsule (D2), between posterior lens capsule and optic papilla (D3) and the axial length. Sixty four transpalpebral ocular ultrasound examinations were performed on 32 Blue fronted Amazon parrots (Amazona aestiva) with no history of previous ophthalmic disease. The measurements were taken in sagital planes using a 10 MHz linear probe without a standoff pad. The mean values for the left eye were; D1 0.17 ± 0.03 cm, D2 0.35 ± 0.02 cm, D3 0.73 ± 0.04 cm and the axial length 1.26 ± 0.06 cm. In the right eye D1 0.17 ± 0.02 cm, D2 0.34 ± 0.02 cm, D3 0.74 ± 0.03 cm and the axial length 1.25 ± 0.05 cm. No significant statistical difference was observed among the birds or between the left and right eye. The description of these parameters will allow the veterinary practitioner to evaluate the structural changes that specific diseases may cause in these animals.

  3. Comparison of Preoperative and Postoperative Ocular Biometry in Eyes with Phakic Intraocular Lens Implantations

    PubMed Central

    Shin, Joo Youn; Lee, Jae Bum; Seo, Kyoung Yul; Kim, Eung Kweon

    2013-01-01

    Purpose To compare preoperative and postoperative ocular biometry in patients with iris-fixated phakic intraocular lens (pIOLs): Artisan and Artiflex. Materials and Methods This study included 40 eyes with Artisan and 36 eyes with Artiflex pIOL implants. Anterior chamber depth (ACD) and axial length (AL) were measured by applanation ultrasonography (A-scan) and partial coherence interferometry (IOLMaster) preoperatively and 3 months after pIOL implantation. Results ACD measurements after Artisan or Artiflex pIOL implantation were smaller than preoperative measurements. Specifically, the difference after Artisan pIOL implantation was -1.07±0.17 mm by A-scan and -0.08±0.08 mm by IOLMaster. The difference after Artiflex pIOL implantation was -1.31±0.15 mm by A-scan and -0.05±0.07 mm by IOLMaster. After Artisan pIOL implantation, differences in AL measurements by A-scan were insignificant (difference: -0.03±0.15 mm), whereas postoperative AL measurements by IOLMaster were significantly longer than preoperative measurements (difference: 0.12±0.07 mm). After Artiflex pIOL implantation, AL measurements by both A-scan and IOLMaster were significantly longer than preoperative measurements (difference: 0.09±0.16 mm by A-scan and 0.07±0.10 mm by IOLMaster). In the Artiflex group, differences in AL measurements by A-scan correlated with the central thickness of the Artiflex pIOL. Conclusion ACD and AL measurements were influenced by iris-fixated phakic IOL implantation. PMID:23918579

  4. Evaluation of healthy equine eyes by use of retinoscopy, keratometry, and ultrasonographic biometry.

    PubMed

    Grinninger, Petra; Skalicky, Monika; Nell, Barbara

    2010-06-01

    To assess natural variations in degree of refraction, corneal curvature, corneal astigmatism, corneal radius, and intraocular distance of healthy equine eyes. 159 horses with healthy eyes that were admitted to a veterinary teaching hospital for nonophthalmic surgeries. Eyes of horses were examined with a retinoscope prior to anesthesia and with a keratograph and A- and B-scan ultrasonographic biometers during surgery. In addition, manual caliper measurements of horizontal and vertical corneal radii were obtained. Mean +/- SD degree of refraction in the horizontal meridian of eyes was -0.06 +/- 0.68 diopters (D). Vitreous body length and horse age correlated negatively with refraction values. The horizontal corneal radius (15.96 +/- 1.28 mm) was larger than the vertical corneal radius (15.02 +/- 1.09 mm). Accordingly, the vertical corneal curvature (21.56 +/- 1.68 D) was greater than the horizontal corneal curvature (22.89 +/- 1.65 D). Axial globe length (40.52 +/- 2.67 mm), anterior chamber depth (6.35 +/- 0.59 mm), lens thickness (12.30 +/- 0.83 mm), and vitreous body length (21.87 +/- 1.85 mm) were positively correlated with body weight, height, and age. Results of keratograph and caliper measurements correlated well for horizontal corneal diameter but poorly for vertical corneal diameter. Results of A- and B-scan ultrasonography differed by < or = 1 mm in 64% of measured eyes. Results of keratometry and ultrasonographic biometry varied widely. Additional research is needed to validate the keratograph used in our study for measurements in equine eyes.

  5. Comparison of the biometric formulas used for applanation A-scan ultrasound biometry.

    PubMed

    Özcura, Fatih; Aktaş, Serdar; Sağdık, Hacı Murat; Tetikoğlu, Mehmet

    2016-10-01

    The purpose of the study was to compare the accuracy of various biometric formulas for predicting postoperative refraction determined using applanation A-scan ultrasound. This retrospective comparative study included 485 eyes that underwent uneventful phacoemulsification with intraocular lens (IOL) implantation. Applanation A-scan ultrasound biometry and postoperative manifest refraction were obtained in all eyes. Biometric data were entered into each of the five IOL power calculation formulas: SRK-II, SRK/T, Holladay I, Hoffer Q, and Binkhorst II. All eyes were divided into three groups according to axial length: short (≤22.0 mm), average (22.0-25.0 mm), and long (≥25.0 mm) eyes. The postoperative spherical equivalent was calculated and compared with the predicted refractive error using each biometric formula. The results showed that all formulas had significantly lower mean absolute error (MAE) in comparison with Binkhorst II formula (P < 0.01). The lowest MAE was obtained with the SRK-II for average (0.49 ± 0.40 D) and short (0.67 ± 0.54 D) eyes and the SRK/T for long (0.61 ± 0.50 D) eyes. The highest postoperative hyperopic shift was seen with the SRK-II for average (46.8 %), short (28.1 %), and long (48.4 %) eyes. The highest postoperative myopic shift was seen with the Holladay I for average (66.4 %) and long (71.0 %) eyes and the SRK/T for short eyes (80.6 %). In conclusion, the SRK-II formula produced the lowest MAE in average and short eyes and the SRK/T formula produced the lowest MAE in long eyes. The SRK-II has the highest postoperative hyperopic shift in all eyes. The highest postoperative myopic shift is with the Holladay I for average and long eyes and SRK/T for short eyes.

  6. Effects of muscarinic receptor modulators on ocular biometry of guinea pigs.

    PubMed

    Fang, Fang; Huang, Furong; Xie, Ruozhong; Li, Cheng; Liu, Yin; Zhu, Ying; Qu, Jia; Zhou, Xiangtian

    2015-01-01

    This study investigated whether pilocarpine and cyclopentolate induce changes in ocular biometry of guinea pigs, in order to understand if guinea pigs have a similar response to these two agents as humans do. Under general anaesthesia, refraction, axial components and surface curvature in various optical interfaces of the eye were measured in 10 guinea pigs (age of 2 weeks) at baseline (0 min) and different time points (5, 10, 20, 30, 60, 90 min) after topical administration of pilocarpine or cyclopentolate. The interval between the two drug treatments for the same animals was at least 24 h. Eyes treated with pilocarpine developed approximately 6D myopia (p < 0.001 from 0 to 90 min) with a decrease in anterior lens radius of curvature (ALRC) (p < 0.001 from 0 to 90 min, repeated measures anova). This myopic shift was moderately correlated to the decreased ALRC (r(2)  = 0.48, p < 0.001). Furthermore, a small but significant increase in the VCD (p < 0.001 from 0 to 30 min, repeated measures anova) with an unchanged AL (p = 0.85 from 0 to 90 min, repeated measures anova) after the drug treatment suggested a transient and mild forward movement of the lens. Cyclopentolate dilated the pupil in all eyes (p < 0.001 from 0 to 90 min, repeated measures anova) but did not change other ocular parameters. The muscarinic agonist, pilocarpine induced a myopic shift mainly due to a decrease in ALRC, suggesting that guinea pigs have an accommodative mechanism similar to that in humans. The minimal changes produced by cyclopentolate could be due to the use of general anaesthesia, which may have reduced the susceptibility of the eye to topical cyclopentolate in the induction of cycloplegia. © 2014 The Authors Ophthalmic & Physiological Optics © 2014 The College of Optometrists.

  7. The role of preoperative biometry in selecting initial contact lens power in the Infant Aphakia Treatment Study.

    PubMed

    Trivedi, Rupal H; Lambert, Scott R; Lynn, Michael J; Wilson, M Edward

    2014-06-01

    To investigate the role of preoperative biometry for selecting initial contact lens power. Patients randomized to receive contact lenses in the Infant Aphakia Treatment Study (IATS) were retrospectively analyzed. Inclusion criteria were availability of both a preoperative immersion axial length measurement and a 1-month postoperative refractive value. The target contact lens power for distance was determined using 1-month postoperative spherical equivalent refraction (after adjusting for a vertex distance) over the known contact lens power. We compared targeted contact lens power for distance with three other treatment techniques: (1) 30 D contact lens (32 D minus 2 D overcorrection for near vision based on IATS protocol); (2) regression-estimated contact lens power of 84.4 - 3.2 × axial length; and (3) IOL power calculated using the Sanders-Retzlaff-Kraff (SRK/T) regression formula with a modified A-constant (112.176). Prediction error (targeted minus estimated contact lens power) and its absolute values were calculated. A total of 34 eyes of 34 patients met inclusion criteria. Age at the time of cataract surgery was 2.4 ± 1.7 months. Follow-up refraction was performed at 31 ± 3 days after surgery. Target contact lens power for distance was 26.0 ± 4.5 D for the IATS cohort (which excluded infants with corneal diameter <9 mm). The mean prediction error was -4.0, -1.0, and -2.0 D and mean absolute prediction error was 4.4, 2.2, and 2.9 D, respectively, for 30 D contact lens, regression, and SRK/T-estimated power. Preoperative biometry can be used to estimate contact lens power for distance if an accurate refraction cannot be obtained initially. Copyright © 2014 American Association for Pediatric Ophthalmology and Strabismus. Published by Mosby, Inc. All rights reserved.

  8. Mid-gestation brain Doppler and head biometry in fetuses with congenital heart disease predict abnormal brain development at birth.

    PubMed

    Masoller, N; Sanz-CortéS, M; Crispi, F; Gómez, O; Bennasar, M; Egaña-Ugrinovic, G; Bargalló, N; Martínez, J M; Gratacós, E

    2016-01-01

    Fetuses with congenital heart disease (CHD) show evidence of abnormal brain development before birth, which is thought to contribute to adverse neurodevelopment during childhood. Our aim was to evaluate whether brain development in late pregnancy can be predicted by fetal brain Doppler, head biometry and the clinical form of CHD at the time of diagnosis. This was a prospective cohort study including 58 fetuses with CHD, diagnosed at 20-24 weeks' gestation, and 58 normal control fetuses. At the time of diagnosis, we recorded fetal head circumference (HC), biparietal diameter, middle cerebral artery pulsatility index (MCA-PI), cerebroplacental ratio (CPR) and brain perfusion by fractional moving blood volume. We classified cases into one of two clinical types defined by the expected levels (high or low) of placental (well-oxygenated) blood perfusion, according to the anatomical defect. All fetuses underwent subsequent 3T-magnetic resonance imaging (MRI) at 36-38 weeks' gestation. Abnormal prenatal brain development was defined by a composite score including any of the following findings on MRI: total brain volume <  10(th) centile, parietoccipital or cingulate fissure depth <  10(th) centile or abnormal metabolic profile in the frontal lobe. Logistic regression analysis demonstrated that MCA-PI (odds ratio (OR), 12.7; P = 0.01), CPR (OR, 8.7; P = 0.02) and HC (OR, 6.2; P = 0.02) were independent predictors of abnormal neurodevelopment; however, the clinical type of CHD was not. Fetal brain Doppler and head biometry at the time of CHD diagnosis are independent predictors of abnormal brain development at birth, and could be used in future algorithms to improve counseling and targeted interventions. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

  9. Evidence of second-trimester changes in head biometry and brain perfusion in fetuses with congenital heart disease.

    PubMed

    Masoller, N; Martínez, J M; Gómez, O; Bennasar, M; Crispi, F; Sanz-Cortés, M; Egaña-Ugrinovic, G; Bartrons, J; Puerto, B; Gratacós, E

    2014-08-01

    To evaluate the associations between congenital heart disease (CHD) and head biometry and cerebrovascular blood flow dynamics at the time of diagnosis of CHD in the second trimester of pregnancy. This was a study of 95 consecutive fetuses diagnosed with CHD. At the time of diagnosis, fetal biometry was performed and brain perfusion was assessed by middle cerebral artery pulsatility index (MCA-PI), cerebroplacental ratio (CPR) and fractional moving blood volume (FMBV). The results were compared with those of 95 normal fetuses matched for gestational age. Median gestational age at diagnosis was 22 + 3 (range, 20 + 0 to 23 + 5) weeks. Fetuses with CHD showed significantly lower MCA-PI and CPR Z-scores (-0.23 vs 0.34 and -0.37 vs 0.30, respectively; both P < 0.001) and higher FMBV Z-scores (2.35 vs 0.15; P < 0.001). FMBV > 95(th) percentile was observed in 81.1% of cases as compared with 10.5% in controls (P < 0.001). Moreover, cases showed significantly smaller biparietal diameter (BPD) and head circumference (HC) Z-scores (-1.61 vs -0.43 and -0.89 vs 0.09, respectively; both P < 0.001), with a higher proportion of BPD and HC measurements below the 5(th) percentile compared with controls (51.6% vs 13.7% and 26.3% vs 4.2%, respectively; both P < 0.001). These findings were more pronounced in those cases with types of CHD associated with compromised oxygenated blood delivery to the brain, such as left outflow tract obstruction and transposition of the great arteries. A high proportion of fetuses with CHD have a smaller head and increased brain perfusion already in the second trimester, suggesting an early onset of the mechanisms leading to poorer neurodevelopment later in life. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

  10. Changes in ocular biometry and anterior chamber parameters after pharmacologic mydriasis and peripheral iridotomy in primary angle closure suspects.

    PubMed

    Razeghinejad, Mohammad Reza; Lashkarizadeh, Hamid; Nowroozzadeh, Mohammad Hossein; Yazdanmehr, Mohammad

    2016-01-01

    The aim of this study was to evaluate the effects of pharmacologic mydriasis and Peripheral Iridotomy (PI) on ocular biometry and anterior chamber parameters in primary angle closure suspects. In this prospective interventional case series, 21 primary angle closure suspects were enrolled. Intraocular pressure, refraction, ocular biometry (Lenstar, LS900), and anterior chamber parameters (Pentacam HR) were measured at four occasions: before PI (before and after mydriasis with phenylephrine) and two weeks after PI (before and after mydriasis). The study was conducted on both eyes and only one eye per patient, in random, was included in the analysis. The mean age of the participants was 60±7 years and 17 (81%) were female. There were no significant differences in intraocular pressure, refraction, keratometry, biometric and anterior chamber parameters between groups, except for anterior chamber volume, which showed increments with PI and mydriasis. The corresponding values for anterior chamber volume were as follows: 88.2±13.7mm(3) before PI, undilated; 106.3±18.8 before PI, dilated; 99.0±14.6 after PI, undilated, and 107.4±16.5 after PI, dilated (P<0.001). This study showed no change in the ocular biometric and anterior chamber parameters including iridocorneal angle after PI and/or pharmacologic mydriasis except for increments in anterior chamber volume. This factor has the potential to be used as a numerical proxy for iris position in evaluating and monitoring patients with primary angle closure suspects after PI. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  11. Characteristics of the Anterior Segment Biometry and Corneal Endothelium in Eyes with Pseudoexfoliation Syndrome and Senile Cataract

    PubMed Central

    Bozkurt, Banu; Güzel, Hüseyin; Kamış, Ümit; Gedik, Şansal; Okudan, Süleyman

    2015-01-01

    Objectives: To evaluate the anterior segment biometric features and corneal endothelial changes in eyes with pseudoexfoliation (PEX) syndrome and senile cataract. Materials and Methods: The central corneal thickness, anterior chamber depth (ACD), pupil diameter, lens thickness, endothelial cell density (ECD), and percentages of polymegathism and pleomorphism of 52 subjects with PEX and cataract were compared with 51 age- and gender-matched control subjects with cataract using optical low-coherence reflectometry (OLCR, Lenstar LS 900; Haag Streit AG, Switzerland) and in-vivo confocal microscopy (Confo Scan 4, Nidek Co. Ltd, Osaka, Japan). Nineteen subjects with PEX syndrome had glaucoma and were using anti-glaucoma medications. Only one eye of the subjects was used in statistical analysis and a p value less than 0.05 was considered statistically significant. Results: None of the OLCR parameters reached statistically significant differences among the 3 groups (ANOVA p>0.05). The percentage of eyes with ACD <2.5 mm was 13.7% in the control group, 24.2% in PEX eyes without glaucoma and 21.1% in PEX eyes with glaucoma, with no statistically significant differences (p=0.45). There was a significant difference in mean ECD among the 3 groups (ANOVA p=0.02), whereas no differences could be found in respect to polymegathism and pleomorphism (p>0.05). Mean ECD was significantly lower in the PEX glaucoma group (2,199.5±176.8 cells/mm2) than the control group (2,363±229.3 cells/mm2) (p=0.02), whereas no difference was found in mean ECD of PEX eyes without glaucoma and the control group (p=0.42). ECD was less than 2,000 cells/mm2 in 15.8% of PEX subjects with glaucoma, 9.8% of control subjects and 6.1% of PEX eyes without glaucoma, with no statistically significant difference (p=0.52). Conclusion: As eyes with both PEX glaucoma and cataract seem to be associated with decreased endothelial cell number, specular or confocal microscopy screening should be done for the patients scheduled for intraocular surgery. PMID:27800230

  12. Full anterior segment biometry with extended imaging range spectral domain optical coherence tomography at 1340 nm

    PubMed Central

    Li, Peng; Johnstone, Murray; Wang, Ruikang K.

    2014-01-01

    Abstract. We demonstrate an extended-imaging-range anterior-segment optical coherence tomography (eAS-OCT) system for the biometric assessment of full AS in human eye. This newly developed eAS-OCT operating at 1340-nm wavelength band is simultaneously capable of an imaging speed of 120 kHz A-line scan rate, an axial resolution of 7.2 μm, and an extended imaging range of up to 16 mm in air. Imaging results from three healthy subjects and one subject with a narrow-angle demonstrate the instrument’s utility. With this system, it can provide anatomical dimensions of AS, including central corneal thickness, anterior chamber width, anterior chamber depth, crystalline lens vault, crystalline lens thickness, angle opening distance (AOD500/AOD750), and the area described by the trabecular-iris space (TISA500/TISA750) at 500/750  μm. We also use eAS-OCT to image and quantify dynamic functional changes of the AS in response to a light stimulus that induces physiological pupillary changes as well as accommodative efforts that induce lens changes. The results show that the described eAS-OCT is able to provide full anatomical biometry for AS and is useful for the studies where the dynamic response of AS compartment to certain stimulus is required. PMID:24752381

  13. Highly reproducible swept-source, dispersion-encoded full-range biometry and imaging of the mouse eye

    NASA Astrophysics Data System (ADS)

    Wang, Ling; Hofer, Bernd; Chen, Yen-Po; Guggenheim, Jeremy A.; Drexler, Wolfgang; Považay, Boris

    2010-07-01

    We report a high-speed, dispersion-encoded, full-range (DEFR) swept-source optical coherence tomography system for in vivo ocular imaging and biometry of small animals. The fast DEFR algorithm removes the depth ambiguity, gives access to objects located at the zero delay position, and doubles the sampling depth to 2×5.0 mm (at -101 to -71 dB sensitivity) in a single scan using 2048 samples/depth scan 0.43 nm line width of a light source operating at 1056 nm with 70 nm tuning range. The acquisition speed (frames of 512 depth scans in 18.3 ms) permits precise on-line monitoring during positioning and provides cross-sectional views of the mouse eye. Preliminary studies demonstrate high-throughput, reproducible assessment of multiple biometric features (e.g., day-to-day reproducibility of axial length measurement +/-5.3 μm) that is insensitive to eye motion sufficient for long-term monitoring.

  14. Assessment of a new averaging algorithm to increase the sensitivity of axial eye length measurement with optical biometry in eyes with dense cataract.

    PubMed

    Hirnschall, Nino; Murphy, Sinead; Pimenides, Dimitris; Maurino, Vincenzo; Findl, Oliver

    2011-01-01

    To assess the capability of new software to decrease the proportion of eyes that have insufficient signal-to-noise ratio (SNR) in optical biometry. Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom. Evaluation of diagnostic test or technology. In a prospective study, consecutive cataract patients coming for biometry who were unsuccessfully measured with the former software (version 4) of the IOLMaster partial coherence interferometry (PCI) device were reevaluated with the new composite software (version 5). Subsequently, in a retrospective study, consecutive cataract patients were measured with software version 5. For unsuccessful scans, the type and intensity of cataract were assessed at the slitlamp. Altogether, 2713 eyes (1956 patients) were included in the study. The prospective study comprised 458 eyes (244 patients), 10.6% of which could not be measured successfully with software version 4. With the composite software, 30% of cases were measured successfully, with a higher proportion (42%) in the posterior subcapsular cataract subgroup. In the retrospective study, of 2255 eyes (1712 patients), 4.7% were not measured successfully using the new algorithm because of white cataract (70 eyes), posterior subcapsular cataract (14 eyes), or dense nuclear cataract combined with posterior subcapsular cataract (13 eyes) or for other reasons (8 eyes). The composite software (version 5) enhanced the SNR, allowing valid measurements in eyes in which optical biometry had previously failed, especially in cases of posterior subcapsular cataract. No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes. Copyright © 2010 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  15. DXA, bioelectrical impedance, ultrasonography and biometry for the estimation of fat and lean mass in cats during weight loss

    PubMed Central

    2012-01-01

    Background Few equations have been developed in veterinary medicine compared to human medicine to predict body composition. The present study was done to evaluate the influence of weight loss on biometry (BIO), bioimpedance analysis (BIA) and ultrasonography (US) in cats, proposing equations to estimate fat (FM) and lean (LM) body mass, as compared to dual energy x-ray absorptiometry (DXA) as the referenced method. For this were used 16 gonadectomized obese cats (8 males and 8 females) in a weight loss program. DXA, BIO, BIA and US were performed in the obese state (T0; obese animals), after 10% of weight loss (T1) and after 20% of weight loss (T2). Stepwise regression was used to analyze the relationship between the dependent variables (FM, LM) determined by DXA and the independent variables obtained by BIO, BIA and US. The better models chosen were evaluated by a simple regression analysis and means predicted vs. determined by DXA were compared to verify the accuracy of the equations. Results The independent variables determined by BIO, BIA and US that best correlated (p < 0.005) with the dependent variables (FM and LM) were BW (body weight), TC (thoracic circumference), PC (pelvic circumference), R (resistance) and SFLT (subcutaneous fat layer thickness). Using Mallows’Cp statistics, p value and r2, 19 equations were selected (12 for FM, 7 for LM); however, only 7 equations accurately predicted FM and one LM of cats. Conclusions The equations with two variables are better to use because they are effective and will be an alternative method to estimate body composition in the clinical routine. For estimated lean mass the equations using body weight associated with biometrics measures can be proposed. For estimated fat mass the equations using body weight associated with bioimpedance analysis can be proposed. PMID:22781317

  16. Transfer of benzo[a]pyrene from microplastics to Artemia nauplii and further to zebrafish via a trophic food web experiment: CYP1A induction and visual tracking of persistent organic pollutants.

    PubMed

    Batel, Annika; Linti, Frederic; Scherer, Martina; Erdinger, Lothar; Braunbeck, Thomas

    2016-07-01

    The uptake of microplastic particles and the transfer of potential harmful substances along with microplastics has been studied in a variety of organisms, especially invertebrates. However, the potential accumulation of very small microplastic particles along food webs ending with vertebrate models has not been investigated so far. Therefore, a simple artificial food chain with Artemia sp. nauplii and zebrafish (Danio rerio) was established to analyze the transfer of microplastic particles and associated persistent organic pollutants (POPs) between different trophic levels. Very small (1-20 μm) microplastic particles accumulated in Artemia nauplii and were subsequently transferred to fish. Virgin particles not loaded with POPs did not cause any observable physical harm in the intestinal tracts of zebrafish, although parts of the particles were retained within the mucus of intestinal villi and might even have been taken up by epithelial cells. The transfer of associated POPs was tested with the polycyclic aromatic hydrocarbon benzo[a]pyrene and an ethoxyresorufin-O-deethylase (EROD) assay for CYP1A induction in zebrafish liver as well as via fluorescence analyses. Whereas a significant induction in the EROD assay could not be shown, because of high individual variation and low sensitivity regarding substance concentration, the fluorescence tracking of benzo[a]pyrene indicates that food-borne microplastic-associated POPs may actually desorb in the intestine of fish and are thus transferred to the intestinal epithelium and liver. Environ Toxicol Chem 2016;35:1656-1666. © 2016 SETAC. © 2016 SETAC.

  17. On the morphology, biometry and biogeography of Lamtopyxis callistoma (Amoebozoa: Arcellinida)

    PubMed Central

    2015-01-01

    Abstract The ultra-structure of the shell and the morphometric variability of soil inhabiting testate amoeba Lamtopyxis callistoma from Madagascar were studied by using light- and scanning electron microscopy. The biometrical characteristic of the species was made on the basis of 75 specimens measured. In addition to the diameter of the shell, six other shell characters were described biometrically for the first time. The analysis of the variation coefficients shows that the studied population of L. callistoma is comparatively homogeneous and almost all measured characters are weakly to moderate variable (CV less than 10%). Scanning electron microscopy (SEM) studies on the shell ultra-morphology show that it has a smooth apertural surface with a thick layer of porous and fibrous organic cement and a rough dorsal surface composed of bigger and angular pieces of quartz. The shell wall has a thickness of about 5-6 µm and is composed of three layers. Unlike the previously accepted opinion that species is characterized by the presence of four teeth, this study shows that population of L. callistoma from Madagascar is comprised of both, specimens with four teeth and specimens with three teeth, in ratio of about 60% to 40%. Taking into account the restricted geographical distribution, large sizes and characteristic apertural morphology of L. callistoma it is assumed that this species, like some bryophilic ‘Nebelas’ with circumaustral distribution (e.g. Apodera vas, Alocodera cockayni, Certesella certesi, Certesella martiali, etc.), can be used as an example that in free-living microbial eukaryotes ‘not everything is everywhere’. PMID:25632260

  18. Hylemetry versus Biometry: a new method to certificate the lithography authenticity

    NASA Astrophysics Data System (ADS)

    Schirripa Spagnolo, Giuseppe; Cozzella, Lorenzo; Simonetti, Carla

    2011-06-01

    When we buy an artwork object a certificate of authenticity contain specific details about the artwork. Unfortunately, these certificates are often exchanged between similar artworks: the same document is supplied by the seller to certificate the originality. In this way the buyer will have a copy of an original certificate to attest that the "not original artwork" is an original one. A solution for this problem would be to insert a system that links together the certificate and a specific artwork. To do this it is necessary, for a single artwork, to find unique, unrepeatable, and unchangeable characteristics. In this paper we propose a new lithography certification based on the color spots distribution, which compose the lithography itself. Due to the high resolution acquisition media available today, it is possible using analysis method typical of speckle metrology. In particular, in verification phase it is only necessary acquiring the same portion of lithography, extracting the verification information, using the private key to obtain the same information from the certificate and confronting the two information using a comparison threshold. Due to the possible rotation and translation it is applied image correlation solutions, used in speckle metrology, to determine translation and rotation error and correct allow to verifying extracted and acquired images in the best situation, for granting correct originality verification.

  19. Biometry of the hypospadic penis after hormone therapy (testosterone and estrogen): A randomized, double-blind controlled trial.

    PubMed

    Paiva, Kelly Christina de Castro; Bastos, André Netto; Miana, Laura Pimenta; Barros, Eveline de Souza; Ramos, Plínio Santos; Miranda, Lara Meneguelli; Faria, Natália Maia; Avarese de Figueiredo, André; de Bessa, José; Netto, José Murillo B

    2016-08-01

    after 90 days follow-up and did not change hormone serum levels. Preoperative use of topical testosterone increases penile size, diameter of the penis and glans. The use of estradiol does not change penile biometry. Side effects occur mainly with the use of testosterone and are transient. No significant and persistent hormonal changes were observed. Copyright © 2016 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

  20. Nonhuman Primate Ocular Biometry

    PubMed Central

    Augusteyn, Robert C.; Maceo Heilman, Bianca; Ho, Arthur; Parel, Jean-Marie

    2016-01-01

    Purpose To examine ocular growth in nonhuman primates (NHPs) from measurements on ex vivo eyes. Methods We obtained NHP eyes from animals that had been killed as part of other studies or because of health-related issues. Digital calipers were used to measure the horizontal, vertical, and anteroposterior globe diameters as well as corneal horizontal and vertical diameters of excised globes from 98 hamadryas baboons, 551 cynomolgus monkeys, and 112 rhesus monkeys, at ages ranging from 23 to 360 months. Isolated lens sagittal thickness and equatorial diameter were measured by shadowphotogrammetry. Wet and fixed dry weights were obtained for lenses. Results Nonhuman primate globe growth continues throughout life, slowing toward an asymptotic maximum. The final globe size scales with negative allometry to adult body size. Corneal growth ceases at around 20 months. Lens diameter increases but thickness decreases with increasing age. Nonhuman primate lens wet and dry weight accumulation is monophasic, continuing throughout life toward asymptotic maxima. The dry/wet weight ratio reaches a maximum of 0.33. Conclusions Nonhuman primate ocular globe and lens growth differ in several respects from those in humans. Although age-related losses of lens power and accommodative amplitude are similar, lens growth and properties are different indicating care should be taken in extrapolating NHP observations to the study of human accommodation. PMID:26780314

  1. Would gestational age and presence of brain anomalies affect interobserver reliability of fetal head biometry? Using off-line analysis of 3-D dataset.

    PubMed

    Salman, Mona S M; Mousa, Hatem A; Twining, Peter; Jones, Nia W; James, David; Momtaz, Mohamed; Aboulghar, Mona; El-Sheikhah, Ahmad; Bugg, George

    2012-01-01

    The objective was to assess interobserver reliability of fetal head biometry using archived three-dimensional (3-D) volumes and the impact of gestational age and presence of brain anomalies on examiners' performance. Seventy nine 3-D volume datasets of fetal head were examined: 27 were normal and 52 had brain abnormalities. Off-line analysis was done by three fetal medicine experts (E1, E2 and E2), all were blinded to history and patient details. Measurements of the biparietal diameter (BPD), head circumference (HC), lateral ventricle (Vp) and transcerebellar diameter (TCD) were compared between examiners and to two-dimensional (2-D) measurements. Comparisons were made at two gestational age groups (≤22 and >22 weeks) and in presence and absence of brain anomalies. The intraclass coefficient showed a significantly high level of measurement agreement between 3-D examiners and 2-D, with values >0.9 throughout (p < 0.001). Bias was evident between 3-D examiners. E2 produced smaller measurements. The mean percentage difference between this examiner and the other two in BPD, HC, Vp and TCD measurements was significant, of 1.6%, 1%, 4.9% and 1.8%, respectively. E1 measured statistically larger for HC and TCD. E3 measured significantly larger for only BPD. The presence of anomalies was of no influence on the 3-D examiners' performance except for E3 who showed bias in BPD measurements only in cases with brain anomalies. Unlike other examiners, bias of E2 was only seen at gestational age group ≤22 weeks. Limits of agreement in measurements between observers were narrow for all parameters but were widest for the Vp measurements, being ±23% of the mean difference. Despite the above bias, the actual mean difference between examiners was small and unlikely to be of any clinical significance. Off-line measurement of fetal head biometry using 3-D volumes is reliable. In our study, presence of brain anomalies was unlikely to influence the reproducibility of measurements

  2. Differences in the Biometry of the Levator Hiatus at Rest, During Contraction, and During Valsalva Maneuver Between Women With and Without Provoked Vestibulodynia Assessed by Transperineal Ultrasound Imaging.

    PubMed

    Thibault-Gagnon, Stéphanie; McLean, Linda; Goldfinger, Corrie; Pukall, Caroline; Chamberlain, Susan

    2016-02-01

    Pelvic floor muscle (PFM) involvement is suspected in the pathophysiology of provoked vestibulodynia (PVD); however, the underlying mechanisms are unclear. PFM morphology can be inferred from the biometry of the levator hiatus determined through dynamic ultrasound imaging. The aim of this study was to determine the nature of PFM involvement in women with PVD via an evaluation of the biometry of the levator hiatus at rest, upon maximal voluntary contraction (MVC) of the PFMs, and upon maximal Valsalva maneuver (MVM). Thirty-eight women with PVD and 39 asymptomatic controls were imaged using 3D transperineal ultrasound. Levator hiatal dimensions (area; left-right [LR] and anteroposterior [AP] diameters) were measured at rest, on MVC, and on MVM. Differences in hiatal dimensions and in relative changes in dimensions from rest to MVC and from rest to MVM were compared between groups using separate 1-way analyses of variance for each measure and task. Analysis of covariance models were used to investigate the impact of levator hiatal dimensions at rest on the relative changes in the levator hiatal dimensions during MVC and MVM. Levator hiatal area, LR, and AP diameters, at rest, on MVC, and on MVM were the main outcome measures. Relative changes in hiatal dimensions were assessed as the percent change in hiatal area, LR diameter, and AP diameter. In comparison with controls, women with PVD had smaller hiatal areas at rest, on MVC, and on MVM, concurrent with smaller LR diameters on MVM. Women with PVD had a significantly smaller change in hiatal area on MVM than controls, but no differences were evident on MVC. In both groups, smaller levator hiatal dimensions at rest were associated with smaller relative decreases in dimensions on MVC and larger relative increases in dimensions on MVM. In comparison to controls, women with PVD appear to have narrower levator hiatus' and less capacity to distend their hiatus on Valsalva. The state of the PFMs at rest appears to

  3. [Influence of HIV-1 and placental malaria co-infection on newborn biometry and Apgar scores in Kinshasa, Democratic Republic of Congo].

    PubMed

    Modia O'Yandjo, A; Foidart, J-M; Rigo, J

    2011-09-01

    The aim of this study was to assess the impact of HIV-1 and placental malaria co-infection on newborn biometry and Apgar scores. 146 HIV-1 infected and 149 HIV-1 uninfected consent mothers and their newborns were recruited. Placental biopsies examination confirmed the presence or absence of placental malaria. Birth weight (BW), placental weight, cranial circumference, brachial perimeter, height, Body Mass Index (BMI) and Apgar scores at 1', 5', 10' were taken. The Chi(2) test and t-Student test were used for data statistical analysis. The global placental malarial infection prevalence was 72% but was 91% in HIV-1 infected vs. 53.7% in HIV-1 uninfected mothers (p<0.0001). The mean BW of HIV-1 co-infected mother's newborns was slightly inferior to that of HIV-1 uninfected mother's babies (3,033±524g vs. 3,236±565g) but this difference was not statistically significant (p>0.05). No other significant biometric differences were noted (p>0.05). But, the co-infection influenced negatively Apgar scores at 5' (p<0.05). HIV-1 co-infected mothers were more frequently exposed to placental malaria infection. The co-infection reduced the Apgar scores taken at the fifth minute. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  4. 'Further Development' of Mendel's legacy? Erich von Tschermak-Seysenegg in the context of Mendelian-biometry controversy, 1901-1906.

    PubMed

    Simunek, Michal; Hoßfeld, Uwe; Breidbach, Olaf

    2012-12-01

    The contribution of Erich von Tschermak-Seysenegg (1871-1962) to the beginning of classical genetics is a matter of dispute. The aim of this study is to analyse, based on newly accessible archive materials, the relevance of his positions and theoretical views in a debate between advocates of early Mendelian explanation of heredity and proponents of biometry, which took place in England around 1901-1906. We challenge not only his role of an 'external consultant', which at the time de facto confirmed his status of 'rediscoverer' of Mendel's work but also analyse his ambivalent positions which are to be seen as a part of 'further development' (Weiterführung), a development of Mendel's legacy as he understood it. Second, there is an interesting aspect of establishing connections within an 'experimental culture' along the Mendel's lines of thought that was parallel to the first step of institutionalizing the new discipline of Genetics after 1905/06. Part of the study is also the analysis of contribution of his older brother Armin von Tschermak-Seysenegg (1870-1952) who--much like in the case of 'rediscovery' of 1900-1901--was for his younger brother an important source of theoretical knowledge. In this particular case, it regarded Bateson's 'Defence' of Mendel from 1902.

  5. Larval development of Lynceus brachyurus (Crustacea, Branchiopoda, Laevicaudata): redescription of unusual crustacean nauplii, with special attention to the molt between last nauplius and first juvenile.

    PubMed

    Olesen, Jørgen

    2005-05-01

    The larval development of "conchostracans" has received only scattered attention. Here I present the results of a study on the larval (naupliar) development and the metamorphosis of Lynceus brachyurus, a member of the bivalved branchiopod order the Laevicaudata. Lynceus brachyurus is the only species of the "Conchostraca" in Denmark. The phylogenetic position of the Laevicaudata has traditionally been a source of controversy, and this study does not solve the question completely. This work focuses on features potentially important for phylogeny. The general appearance of the larvae of L. brachyurus has been known for more than a century and a half, and some of its unique features include a large, larval dorsal shield; a huge, plate-like labrum; and a pair of immovable, horn-like antennules. However, many details relating to limb morphology, potentially important for phylogeny, have not been studied previously. Based on size categories, five or six larval stages can be recognized. The larvae approximately double their length and width during development (length: 230-520 microm). Most morphological features stay largely unchanged during development, but the antennal coxal masticatory spines are significant exceptions: they become bifid after one of the first molts. In all larval stages only the antennae and the mandibles actively move. In late naupliar stages the trunk limbs become visible as rows of laterally placed, undeveloped, and still immovable lobes. Swimming is performed by the antennae, whereas the mandibles appear to be involved mainly in feeding, as in other branchiopod larvae. The last naupliar stage undergoes a small metamorphosis to the first juvenile stage, the details of which in part were studied by following the premolt juvenile condition through the cuticle of the last stage nauplius. Among other changes there is a characteristic change in the shape and morphology of the univalved dorsal naupliar shield to a bivalved juvenile carapace. The general

  6. Five-dimensional long bones biometry for estimation of femur length and fetal weight at term compared to two-dimensional ultrasound: a pilot study.

    PubMed

    Laban, Mohamed; Alanwar, Ahmed A; Etman, Mohamed K; Elsokkary, Mohammed S; Elkotb, Ahmed M; Hasanien, Ahmad S; KhalafAllah, Ali E; Noah, Nancy M

    2017-07-27

    This study aimed to evaluate accuracy of five-dimensional long bones (5D LB) compared to two-dimensional ultrasound (2DUS) biometry to predict fetal weight among normal term women. Fifty six normal term women were recruited at Ain Shams Maternity Hospital, Egypt from 14 May to 30 November 2015. Fetal weight was estimated by Hadlock's IV formula using 2DUS and 5D LB. Estimated fetal weights (EFW) by 2DUS and 5D LB were compared with actual birth weights (ABW). Mean femur length (FL) was 7.07 ± 0.73 cm and 6.74 ± 0.67 cm by 2DUS and 5D LB (p = .02). EFW was 3309.86 ± 463.06 g by 2DUS and 3205.46 ± 447.85 g by 5D LB (p = .25). No statistical difference was observed between ABW and EFW by 2DUS (p = .7) or 5D LB (p = .45). Positive correlation was found between EFW by 2DUS, 5D LB, and ABW (r = 0.67 and 0.7; p < .001). There was strong agreement between FL measured by 2DUS and 5D LB (ICC = 0.78), and perfect agreement between EFW by 2DUS and EFW by 5D LB (ICC = 0.918). 2DUS and 5D LB showed mean absolute percentage error for EFW of 10 ± 7% and 8 ± 7% compared to ABW (p = .15). 2DUS and 5D LB had same accuracy for fetal weight estimation at normal term pregnancy.

  7. A STUDY OF WORK-PRODUCING CHARACTERISTICS OF UNDERWATER OPERATIONS.

    DTIC Science & Technology

    PERFORMANCE(HUMAN), UNDERWATER), PERFORMANCE(HUMAN), TORQUE, SYSTEMS ENGINEERING, JOB ANALYSIS, ANALYSIS OF VARIANCE, ENVIRONMENTAL TESTS, BIOMETRY, PULSE RATE, HEART , OXYGEN CONSUMPTION, ENERGY, SKIN(ANATOMY), TEMPERATURE

  8. Gestational Age Assessment in the Ghana Randomized Air Pollution and Health Study (GRAPHS): Ultrasound Capacity Building, Fetal Biometry Protocol Development, and Ongoing Quality Control

    PubMed Central

    Boamah, Ellen A; Asante, KP; Ae-Ngibise, KA; Kinney, Patrick L; Jack, Darby W; Manu, Grace; Azindow, Irene T; Owusu-Agyei, Seth

    2014-01-01

    Background Four million premature deaths occur yearly as a result of smoke from cooking fires. The Ghana Randomized Air Pollution and Health Study (GRAPHS) is underway in the Kintampo North municipality and South district of rural Ghana to evaluate the impact of improved cook stoves introduced during pregnancy on birth weight and childhood pneumonia. These hypotheses are being tested in a cluster-randomized intervention trial among 1415 maternal-infant pairs within 35 communities assigned to a control arm (traditional cooking) or one of two intervention arms (cooking with an improved biomass stove; cooking with liquefied petroleum gas stoves). Objective The trial is designed to ensure delivery of the stove intervention prior to the period of maximal fetal growth. To answer questions about the impact of household air pollution on pregnancy outcome, accurate gestational age assessment is critical. This manuscript describes in detail the development of the gestational dating protocol, intensive ultrasound training involved, ultrasound capacity building, and ultrasound quality control program. Methods Ultrasound training occurred in several phases over the course of 2 years. Training included a basic obstetric ultrasound course offered to all midwives performing antenatal care at the two study hospitals, followed by a more intense period of hands-on training focused on fetal biometry for a select group of providers demonstrating aptitude in the basic course. A standard operating procedure was developed describing how to obtain all fetal biometric measurements. Consensus was obtained on how biometric images are used in the trial to establish gestational age and estimate the delivery date. An ongoing ultrasound quality control program including the use of an image scorecard was also designed. Results Publication of trial results is anticipated in late 2016. Conclusions Use of ultrasound should be strongly considered in field-based trials involving pregnant women to

  9. [Morphology and biometry of eggs and larvae of Strongyloides sp. Grassi, 1879 (Rhabditoidea: Strongyloididae), a gastrointestinal parasite of Hydrochaeris hydrochaeris (Linnaeus, 1766) (Rodentia: Hydrochaeridae), in the municipality of Juiz de Fora, Minas Gerais, Brazil].

    PubMed

    Vieira, Fabiano M; Lima, Sueli de S; Bessa, Elisabeth Cristina de A

    2006-01-01

    An important method to diagnose and study the helminthofauna of wild animals is to examine the host's feces to find eggs and larvae, seeking to identify the parasites and study their morphobiology. The objective of the present work is to provide morphological and biometric data on the eggs and larvae of Strongyloides sp., a capybara gastrointestinal parasite. Using the technique of Gordon and Whitlock, simple flotation and the modified Baermann examination, capybara fecal samples were selected based on a criterion of the highest proportion of eggs and larvae in the initial development stages, for morphometric description of eggs, L1, L2 and L3 of Strongyloides sp. From past reports of parasitism in Hydrochaeris hydrochaeris, we suspect that the eggs and larvae in this study are of Strongyloides chapini Sandground, 1925, which constitutes the first description of these stages for this species of nematode. Nevertheless, the morphology and biometry data of these stages demonstrate that they are similar to those of other species of the Strongyloides genus.

  10. Fine morphology of frontal filaments in nauplii of cirriped crustaceans.

    PubMed

    Obukhova, A L; Voronezhskaya, E E; Malakhov, V V

    2016-05-01

    Fine morphology of the frontal filaments (FFs) at all nauplius stages of two barnacle species (Verruca stroemia and Hesperibalanus hesperius) has been investigated by scanning electron microscopy. FFs have been detected at the second nauplius stage and persist during all stages. FFs contain a wide proximal and a fine distal parts, but they are not actually separated as segments of the limbs, and the area between them looks like a single cuticular crease. Apical and subapical pores have been found at the top of each FF in the larvae of both species, which may indicate the chemoreceptor function of these organs.

  11. Muscular Biometry With Magnetic Resonance Imaging

    DTIC Science & Technology

    2001-10-25

    contribution of Dr H. Mallouche of the Centre hospitalier universitaire de Montréal ( CHUM ). During his stay in Montreal , A. Malanda was supported by...s) and Address(es) Institut de Genie Biomedical Universite de Montreal Canada Performing Organization Report Number Sponsoring/Monitoring Agency

  12. Biometry, biometrics, biostatistics, bioinformatics,..., bio-X.

    PubMed

    Molenberghs, Geert

    2005-03-01

    Recent scientific evolutions force us to rethink our profession's position on the scientific map, in relation to our neighboring professions, the ones with which we traditionally have strong collaborative links as well as the newly emerging fields, but also within our own, diverse professional group. We will show that great inspiration can be drawn from our own history, in fact from the early days of the Society. A recent inspiring example has been set by the late Rob Kempton, who died suddenly just months before he was to become President of the International Biometric Society.

  13. Biometry Staff | Division of Cancer Prevention

    Cancer.gov

    The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

  14. Computing retinal contour from optical biometry.

    PubMed

    Faria-Ribeiro, Miguel; López-Gil, Norberto; Navarro, Rafael; Lopes-Ferreira, Daniela; Jorge, Jorge; González-Méijome, Jose Manuel

    2014-04-01

    To describe a new methodology that derives horizontal posterior retinal contours from partial coherence interferometry (PCI) and ray tracing using the corneal topography. Corneal topography and PCI for seven horizontal visual field eccentricities correspondent to the central 60 degrees of the posterior pole were obtained in 55 myopic eyes. A semicustomized eye model based on the subject's corneal topography and the Navarro eye model was generated using Zemax-EE software. The model was used to compute the optical path length in the seven directions where PCI measurements were obtained. Vitreous chamber depth was computed using the PCI values obtained at each of those directions. Matlab software was developed to fit the best conic curve to the set of points previously obtained. We tested the limit in the accuracy of the methodology when the actual cornea of the subject is not used and for two different lens geometries. A standard eye model can induce an error in the retina sagitta estimation of the order of hundreds of micrometers in comparison with the semicustomized eye model. However, the use of a different lens model leads to an error of the order of tens of micrometers. The apical radius and conic constant of the average fit were -11.91 mm and -0.15, respectively. In general, a nasal-temporal asymmetry in the retina contour was found, showing mean larger values of vitreous chamber depth in the nasal side of the eye. The use of a semicustomized eye model, together with optical path length measured by PCI for different angles, can be used to predict the retinal contour within tenths of micrometers. This methodology can be useful in studies trying to understand the effect of peripheral retinal location on myopia progression as well as modeling the optics of the human eye for a wide field.

  15. Seed and Germination Characteristics of 20 Amazonian Liana Species

    PubMed Central

    Roeder, Mareike; Ferraz, Isolde D. K.; Hölscher, Dirk

    2013-01-01

    Lianas are an important component of tropical forests, and may reach their highest densities in disturbed areas. However, information on seed and germination characteristics is scarce. Twenty Amazon liana species were screened for their germination characteristics, including light dependence, tolerance of desiccation and of alternating temperatures; these characteristics are considered important for the germination success in areas with relatively open canopies. Between 31–1,420 seeds per species were available, as 15 species seeds came from one mother plant. We studied seed biometry and conducted germination trials with fresh seeds (12 h light daily, or dark) and desiccated seeds at 25 °C. Germination at alternating temperatures (20/30 °C, 15/35 °C) was analyzed for nine species. Of the 20 species, eight species with the largest seeds had desiccation sensitive seeds; this is the first record for species of four genera and one family, where only desiccation tolerant seeds are otherwise recorded. Light-dependent germination was found in three species (0.01–0.015 g) and is the first record for two; however, results were based on seeds from one plant per species. Alternating temperatures of 15/35 °C decreased final germination of four out of nine species, and response to 20/30 °C cycles varied compared to constant 25 °C. Seed and germination characteristics of the species ranged from pioneer to climax traits indicating that establishment of lianas from seeds may be confined to species specific niches. PMID:27137363

  16. Retina and Optic Disc Characteristics in Amblyopic and Non-amblyopic Eyes of Patients with Myopic or Hyperopic Anisometropia

    PubMed Central

    Taşkıran Çömez, Arzu; Şanal Ulu, Elif; Ekim, Yeliz

    2017-01-01

    Objectives: To compare retinal and optic disc characteristics between amblyopic and non-amblyopic eyes in patients with myopic and hyperopic anisometropia measured with optical coherence tomography (OCT). Materials and Methods: Patients with myopic (25 patients: 17 female, 8 male; median age 27 years, range 16-40 years) and hyperopic (31 patients: 19 female, 12 male; median age 20 years, range 13-41 years) anisometropic amblyopia were included. Eye examination included determination of best-corrected visual acuity (BCVA) with a Snellen chart, measurement of manifest and cycloplegic refraction after pupillary dilation, alternate cover testing, globe movement evaluation, A-scan biometry for axial length, biomicroscopy, fundus examination, and OCT scanning. Main outcome measures were spherical equivalence, BCVA, axial length, retinal nerve fiber layer (RNFL) thickness, macular thickness, macular volume, and optic disc area. Results: In both myopic and hyperopic patients, the absolute value of the mean spherical equivalence was significantly greater in the amblyopic than non-amblyopic eyes, and the mean BCVA was significantly less in the amblyopic than the non-amblyopic eyes. In both myopic and hyperopic patients, there were no significant differences in mean RNFL thickness, macular thickness, macular volume, axial length, or optic disc area between amblyopic and non-amblyopic eyes. Conclusion: The amblyopic process may have no significant effect on the RNFL, macula, or optic disc. Further studies with more patients, including postmortem studies, may clarify the retinal, histopathologic, and anatomic differences between amblyopic and non-amblyopic eyes. PMID:28182148

  17. Sperm characteristics in plains (Bison bison bison) versus wood (Bison bison athabascae) bison.

    PubMed

    Pegge, Raymond B G; Krishnakumar, Sulochana; Whiteside, Douglas; Elkin, Brett; Parlevliet, Joyce M; Thundathil, Jacob C

    2011-04-15

    The objective was to compare sperm characteristics between the two subspecies of North American bison, plains bison (Bison bison bison) and wood bison (Bison bison athabascae). Frozen-thawed ejaculated sperm from age-matched plains (n = 3) and wood (n = 2) bison were evaluated for morphometry, motility, viability, protein profile, and in vitro fertilization characteristics. Sperm morphometry and motility were assessed with computer-based systems, viability was assessed with SYBR-14 and propidium iodide, and fertilizing ability was determined using a heterologous in vitro fertilization system (using bovine oocytes). For plains versus wood bison, there were significant differences for head width (4.76 ± 0.22 vs 4.71 ± 0.19 μm; mean ± SD), head area (35.64 ± 1.91 vs 34.72 ± 2.64 μm(2)), head perimeter (23.61 ± 0.68 vs 23.31 ± 0.98 μm), midpiece length (14.58 ± 0.4 vs 14.36 ± 0.51 μm), midpiece width (0.81 ± 0.06 vs 0.79 ± 0.07 μm), and tail length (46.61 ± 2.15 vs 45.98 ± 2.08 μm). However, there was no significant difference in head length (overall, 9.04 ± 0.37 μm), progressive motility (41.16 ± 8.39%), or viability (41.58 ± 5.58%). Based on two-dimensional gel electrophoresis, 93 out of 113 protein spots were similar in their expression patterns. Furthermore, we inferred that differences in sperm biometry between these subspecies did not affect in vitro fertilization percentage (overall, 82.62 ± 12.13%). Based on these findings, we concluded that plains bison were an appropriate research model for developing reproductive technologies for wood bison.

  18. Characteristic Curves.

    ERIC Educational Resources Information Center

    Walkiewicz, Thomas A.; Kirk, James R.

    1994-01-01

    Describes an experiment designed to help students gain a better understanding of the characteristics of various electronic components by incorporating a dual-trace oscilloscope in the X-Y mode in addition to direct observations of phase shifts of various signals into a laboratory exercise. (ZWH)

  19. Water characteristics

    SciTech Connect

    Smith, E.D.

    1981-06-01

    Recent research on water characteristics is cited in this review article. Acid precipitation has been noted as one of the major environmental problems of the current decade. It poses a serious challenge to national and international bodies to protect water quality. Considerable interest was voiced in 1980 over the causes and effects, prevention and control of acid rain. One study estimated that acid rain was causing an estimated annual $5 billion loss in crop, forest, and aquatic yields. Several conferences were held during 1980 on acid rain problems. Groundwater contamination from acid rain was cited as one of the many current and anticipated problems in maintaining a clean and healthful water supply. Acid rain and vegetation interactions were studied in depth, as were the effects of acid precipitation on aquatic organisms. A procedure was developed which may be useful in the quantification of acid rain via isolated precipitation events. Acid precipitation was studied in forest environments. Two efforts assessed the potential for acid rain to leach into the soil. 154 references.

  20. Biometry and the IBS--Strength through diversity.

    PubMed

    Mead, Andrew

    2009-03-01

    The International Biometric Society (IBS) brings together members from a diversity of cultural backgrounds, organized into geographically based Regions and National Groups, and covering a diverse range of interests, in terms of both methodological topics and application areas. We briefly reflect on how the historical development of our science, society, and international conferences reflects this diversity, with a focus on the history of the British and Irish Region of the IBS. Then, by considering the cultural/geographical diversity of the society, and the scientific diversity of the society and biometricians, we identify both some strengths of the society (diverse topics for meetings arranged across the world, application of biometrical methods to diverse application areas, management of the society by members from a diversity of backgrounds) and also some current challenges (electronic delivery of journals and other information, the diversity of application areas addressed by members of the society, improving links with the scientific societies of those who motivate our research). Finally, we illustrate the diversity of scientific problems that each of us face in our roles as biometricians.

  1. Foetal biometry in polyhydramnios: Does femur length fall behind?

    PubMed

    Ipek, Ali; Idilman, Ilkay S; Kurt, Aydın; Cay, Nurdan; Unal, Ozlem; Erdogan, Beyza Doganay; Keskin, Huseyin Levent; Arslan, Halil

    2016-01-01

    We aimed to identify the growth patterns in polyhydramnios, and therefore evaluated 108 singleton pregnancies complicated with polyhydramnios according to the changes in biparietal diameter (BPD), abdominal circumference (AC) and femur length (FL) percentiles. The pregnancy outcomes according to the growth features were analysed. In the study population, BPD and AC percentiles exhibited a significant increase (p = 0.023 and 0.05, respectively), although FL percentiles showed a significant decrease (p = 0.006) according to the changes in third trimester relative to second trimester. In the overgrown group (n = 52), the FL/BPD ratio was lower (p < 0.001), with more foetuses with FL/BPD ratios below 71 (p = 0.05). In conclusion, there was a significant increase in BPD and AC percentiles and a decrease in FL percentiles in third trimester relative to second trimester in foetuses with polyhydramnios. However, we observed a shorter FL and a lower FL/BPD ratio without associated skeletal dysplasia in overgrown foetuses.

  2. Biometry Meetings and Events | Division of Cancer Prevention

    Cancer.gov

    The Division of Cancer Prevention (DCP) conducts and supports research to determine a person's risk of cancer and to find ways to reduce the risk. This knowledge is critical to making progress against cancer because risk varies over the lifespan as genetic and epigenetic changes can transform healthy tissue into invasive cancer.

  3. Optical biometry of biological tissues by ellipsoidal reflectors

    NASA Astrophysics Data System (ADS)

    Bezuglyi, M. A.; Pavlovets, N. V.

    2013-06-01

    Possibilities of measuring systems that uses ellipsoidal reflectors for determining the optical parameters of biological tissue are studied. The modified inverse Monte Carlo method was designed for biomedical photometric system "biological tissue - ellipsoidal mirror."

  4. Temperature and salinity effects on cadmium toxicity on lethal and sublethal responses of Amphibalanus amphitrite nauplii.

    PubMed

    Piazza, Veronica; Gambardella, Chiara; Canepa, Sara; Costa, Elisa; Faimali, Marco; Garaventa, Francesca

    2016-01-01

    The official protocol of an ecotoxicological assay employing larvae of the crustacean Amphibalanus amphitrite as a model organism has recently been published by the Italian regulatory authority UNICHIM. Such assay is now one of the applicable tests for water quality assessment under Italian law. While specific temperature and salinity values are recommended by ecotoxicology bioassay protocols for test set up, little information is available on response changes in case of parameter variations. In particular, information is totally lacking for this innovative model organism. Under the standard test protocol, 20°C and 37‰ temperature and salinity, respectively, are required to be set in A. amphitrite bioassay. In order to evaluate the environmental relevance of the test, laboratory experiments simulating the effect on larval responses due to variations of temperature and salinity expected in field collected samples were carried out. The effect of temperature and salinity changes on different end-points, involving increasing sensitivity levels, has been investigated, with and without the presence of cadmium nitrate, Cd(NO3)2, as a reference toxicant, to determine the possible interactions between pollutants and environmental parameters fluctuations. Three end-points - mortality, immobilization, and swimming speed alteration - were measured in order to evaluate the impact of a wide range of temperature (5, 10, 15, 20, 25, 30, 35, 40°C) and salinity values (10, 20, 30, 37, 40, 50, 60, 70‰) on response variation after 24 and 48h of exposure. For each parameter, a Non-Effect Range (NER) - namely the limit values within which no effect related to environmental parameter changes is observed - has been defined. For both parameters, NER resulted to be wider for the less sensitive end-points - such as mortality and immobilization - and for shorter exposure time (24h). Later, the same end-points have been evaluated by exposing the same organisms to a reference toxic compound, Cd(NO3)2 (0, 0.2, 0.4, 0.8, 1.6, 3.2mg/L), within the detected NER both for temperature and salinity. LC50 and EC50 values have been calculated for each end-point after 24 and 48h. Cadmium toxicity was shown to decrease at higher salinity values and increase at higher temperatures. Obtained results offer a better bioassay characterization, and the possibility of a more realistic estimation of ecotoxicological assessments performed on field collected samples. Further studies are needed, especially to investigate the effects of simultaneous salinity and temperature changes on end-points.

  5. Design and baseline characteristics of a population-based study of eye disease in southern Chinese people: the Dongguan Eye Study.

    PubMed

    Meng, Qianli; Cui, Ying; Zhang, Min; Zhang, Lixin; Zhang, Liang; Zhang, Jinxin; Kuang, Jian; Liu, Qingyang; Zheng, Yang; Luo, Zhongling; Liu, Huikun; Zhu, Guoping; Cai, Jingjing; Zhang, Guanrong; Wen, Xingxuan; Guo, Haike

    2016-04-01

    To describe the study design, methodology and baseline characteristics of the Dongguan Eye Study. Population-based, cross-sectional study A total of 8952 rural-dwelling residents aged 40 years or older in Hengli, Dongguan. The Dongguan Eye Study was conducted from September 2011 to February 2012. The interview covered demographic data, socio-economic status and health- and vision-related quality of life. Physical measurements included height, weight, waist and hip circumference, heart rate and blood pressure. Laboratory tests included fasting blood glucose, haemoglobin A1c, oral glucose tolerance, serum total cholesterol, triglycerides, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, serum creatinine, blood urea nitrogen and uric acid. Ophthalmic examinations included visual acuity and autorefraction testing, intraocular pressure measurement, slit-lamp examination, ocular biometry, gonioscopy, fundus photography, retinal nerve fibre layer imaging and visual field testing. Prevalence and risk factors for visual impairment, blindness, eye diseases and their associations with systemic medical indicators or health-related lifestyles, as well as epidemiological data on diabetic subjects. Methodology, response rates and baseline characteristics are presented. Of the 11 357 individuals eligible for the Dongguan Eye Study, 8952 (78.82%) subjects participated. All participants were self-identified Han Chinese. The average age was 54.0 years, 59.9% were female, 48.4% were farmers and 77.2% had elementary or junior middle school educational levels. The average body mass index and waist-hip ratio were 24.6 ± 3.9 kg/m(2) and 0.9 ± 0.2. Data from the Dongguan Eye Study provide information concerning the prevalence, risk factors and impacts of eye diseases in rural residents undergoing urbanization in southern China. © 2015 Royal Australian and New Zealand College of Ophthalmologists.

  6. Effect of Ramadan fasting in tropical summer months on ocular refractive and biometric characteristics.

    PubMed

    Nowroozzadeh, Mohammad Hosein; Mirhosseini, Amirhossein; Meshkibaf, Mohammad Hassan; Roshannejad, Javad

    2012-03-01

    Islamic Ramadan is the month of fasting, in which intake of food and drink is restricted from sunrise until sunset. The objective of the present study was to find out the effect of altered eating habits during Ramadan fasting on ocular refractive and biometric properties. In this prospective case series, 40 eyes of 22 healthy volunteers with a mean age of 60.55 ± 12.20 years were enrolled. Patients with any systemic disorder and eyes with pathology or previous surgery were excluded. One month before Ramadan (at 8.00 am), during Ramadan fasting (at 8.00 am and 4.00 pm) and one month later during the non-fasting period (at 8.00 am), ocular refractive and biometric characteristics were measured using an autokeratorefractometer (Auto-Kerato-Refractometer KR-8900; Topcon Co, Tokyo, Japan) and contact ultrasonic biometry (Nidek Echoscan US 800; Nidek Co, Tokyo, Japan). Anterior chamber depth was significantly increased during fasting compared with baseline measurements and returned to baseline one month after Ramadan (3.22 ± 0.07 mm and 4.33 ± 0.17 mm for non-fasting and fasting, respectively; p < 0.001). The anterior chamber depth measurements were significantly larger at 8.00 am during fasting compared with 4.00 pm (p = 0.01). Axial length was significantly decreased during fasting and returned to baseline one month after Ramadan (23.09 ± 0.14 mm and 22.65 ± 0.18 mm, for non-fasting and fasting, respectively; p < 0.001). Intraocular lens power calculations were significantly increased during fasting and returned to baseline one month after Ramadan (SRK-T formula: 21.46 ± 0.27 D and 22.92 ± 0.46 D, for non-fasting and fasting, respectively; p < 0.001). There were no significant differences in spherical equivalent, corneal astigmatism, mean keratometry and flatter and steeper corneal radii of curvature between time intervals. Ramadan fasting is associated with statistically significant alterations in anterior chamber depth and axial length that result in both

  7. Fetal sonographic characteristics associated with shoulder dystocia in pregnancies of women with type 1 diabetes.

    PubMed

    Secher, Anna L; Bytoft, Birgitte; Tabor, Ann; Damm, Peter; Mathiesen, Elisabeth R

    2015-10-01

    Shoulder dystocia is a rare but severe complication of vaginal delivery and diabetic women are at high risk. The aim of this study was to identify fetal sonographic and maternal glycemic characteristics associated with shoulder dystocia in pregnant women with type 1 diabetes. Twelve cases (5%) of shoulder dystocia among 241 consecutive vaginal deliveries in women with type 1 diabetes followed at Rigshospitalet University Hospital in 2009-2013 were retrospectively identified in a local database. Fetal sonographic and clinical data were compared with 69 women with type 1 diabetes and uncomplicated vaginal deliveries. Women experiencing shoulder dystocia compared with women with uncomplicated deliveries had a higher glycated hemoglobin (HbA1c) in early pregnancy [median 7.0% (range 5.9-8.1) vs. 6.6% (range 5.4-10.0, P = 0.04)], whereas in late pregnancy, HbA1c in the two groups of women was comparable [6.1% (range 5.5-6.9) vs. 6.0% (range 4.7-8.4, P = 0.30)]. Fetal biometry at 36 weeks showed a higher estimated fetal weight of 3597 g (range 3051-4069) vs. 2989 g (range 2165-4025), P < 0.001, corresponding to 20% (4-41%) vs. 5% (-20 to 44%) above the mean estimated fetal weight for gestational age (P = 0.002) and a greater abdominal circumference SD score of 2.51 (range 1.56-4.20) vs. 1.33 (range -1.08 to 4.25), P = 0.001). Head circumference was comparable. Vacuum extraction was more frequent during deliveries with shoulder dystocia (58 vs. 17%, P = 0.005). Seven (58%) newborns with shoulder dystocia had brachial plexus injuries, fractures, intra-abdominal bleeding or needed resuscitation. Excessive estimated fetal weight and abdominal circumference at 36 weeks' sonographic examination may help in identifying diabetic women at high risk of later shoulder dystocia. © 2015 Nordic Federation of Societies of Obstetrics and Gynecology.

  8. Are streamflow recession characteristics really characteristic?

    NASA Astrophysics Data System (ADS)

    Stoelzle, M.; Stahl, K.; Weiler, M.

    2012-09-01

    Streamflow recession has been investigated by a variety of methods, often involving the fit of a model to empirical recession plots to parameterize a non-linear storage-outflow relationship. Such recession analysis methods (RAMs) are used to estimate hydraulic conductivity, storage capacity, or aquifer thickness and to model streamflow recession curves for regionalization and prediction at the catchment scale. Numerous RAMs have been published, but little is known about how characteristic the resulting recession models are to distinguish characteristic catchment behavior. In this study we combined three established recession extraction methods with three different parameter-fitting methods to the power-law storage-outflow model to compare the range of recession characteristics that result from the application of these different RAMs. Resulting recession characteristics including recession time and corresponding storage depletion were evaluated for 20 meso-scale catchments in Germany. We found plausible ranges for model parameterization, however, calculated recession characteristics varied over two orders of magnitude. While recession characteristics of the 20 catchments derived with the different methods correlate strongly, particularly for the RAMs that use the same extraction method and while they rank the catchments relatively consistent, there are still considerable differences among the methods. To elucidate this variability we discuss the ambiguous roles of recession extraction procedures and the parameterization of storage-outflow model and the limitations of the presented recession plots. The results suggest strong limitations to the comparability of recession characteristics derived with different methods, not only in the model parameters but also in the relative characterization of different catchments. A multiple methods approach to investigate streamflow recession characteristics should be considered for applications whenever possible.

  9. Wetland Characteristics and Denitrification

    EPA Science Inventory

    This presentation serves as an initial summary of our wetland field work's watershed characteristics hydrologic characteristics, water quality measurements, and denitrification assays. We present our measurement results in the context of wetland type (Estuarine, Freshwater Mars...

  10. Thermistor Characteristics and Stability.

    ERIC Educational Resources Information Center

    Fricker, H. S.

    1987-01-01

    Discusses the uses of thermistors in teaching electronics and semiconductors. Describes how to experimentally measure and graph the characteristics of a thermistor. Suggests one possible approach to understand the shapes of the characteristics. (CW)

  11. Theory of Characteristics

    NASA Technical Reports Server (NTRS)

    Tollmien, W.

    1949-01-01

    The theory of characteristics will be presented generally for quasilinear differential equations of the second order in two variables. This is necessary because of the manifold requirements to be demanded from the theory of characteristics.

  12. Thermistor Characteristics and Stability.

    ERIC Educational Resources Information Center

    Fricker, H. S.

    1987-01-01

    Discusses the uses of thermistors in teaching electronics and semiconductors. Describes how to experimentally measure and graph the characteristics of a thermistor. Suggests one possible approach to understand the shapes of the characteristics. (CW)

  13. Are streamflow recession characteristics really characteristic?

    NASA Astrophysics Data System (ADS)

    Stoelzle, M.; Stahl, K.; Weiler, M.

    2013-02-01

    Streamflow recession has been investigated by a variety of methods, often involving the fit of a model to empirical recession plots to parameterize a non-linear storage-outflow relationship based on the dQ/dt-Q method. Such recession analysis methods (RAMs) are used to estimate hydraulic conductivity, storage capacity, or aquifer thickness and to model streamflow recession curves for regionalization and prediction at the catchment scale. Numerous RAMs have been published, but little is known about how comparably the resulting recession models distinguish characteristic catchment behavior. In this study we combined three established recession extraction methods with three different parameter-fitting methods to the power-law storage-outflow model to compare the range of recession characteristics that result from the application of these different RAMs. Resulting recession characteristics including recession time and corresponding storage depletion were evaluated for 20 meso-scale catchments in Germany. We found plausible ranges for model parameterization; however, calculated recession characteristics varied over two orders of magnitude. While recession characteristics of the 20 catchments derived with the different methods correlate strongly, particularly for the RAMs that use the same extraction method, not all rank the catchments consistently, and the differences among some of the methods are larger than among the catchments. To elucidate this variability we discuss the ambiguous roles of recession extraction procedures and the parameterization of the storage-outflow model and the limitations of the presented recession plots. The results suggest strong limitations to the comparability of recession characteristics derived with different methods, not only in the model parameters but also in the relative characterization of different catchments. A multiple-methods approach to investigating streamflow recession characteristics should be considered for applications

  14. Characteristics of Successful Entrepreneurs.

    ERIC Educational Resources Information Center

    McClelland, David C.

    1987-01-01

    Comparison of characteristics of 12 average and 12 superior small business people in three developing nations (India, Malawi, and Ecuador) found proactive qualities such as initiative and assertiveness, achievement orientation, and commitment to others characteristic of successful entrepreneurs. Other expected qualities (self-confidence,…

  15. Characteristics of Successful Entrepreneurs.

    ERIC Educational Resources Information Center

    McClelland, David C.

    1987-01-01

    Comparison of characteristics of 12 average and 12 superior small business people in three developing nations (India, Malawi, and Ecuador) found proactive qualities such as initiative and assertiveness, achievement orientation, and commitment to others characteristic of successful entrepreneurs. Other expected qualities (self-confidence,…

  16. Aircraft compass characteristics

    NASA Technical Reports Server (NTRS)

    Peterson, John B; Smith, Clyde W

    1937-01-01

    A description of the test methods used at the National Bureau of Standards for determining the characteristics of aircraft compasses is given. The methods described are particularly applicable to compasses in which mineral oil is used as the damping liquid. Data on the viscosity and density of certain mineral oils used in United States Navy aircraft compasses are presented. Characteristics of Navy aircraft compasses IV to IX and some other compasses are shown for the range of temperatures experienced in flight. Results of flight tests are presented. These results indicate that the characteristic most desired in a steering compass is a short period and, in a check compass, a low overswing.

  17. Skin characteristics (image)

    MedlinePlus

    ... covering the forehead, cheeks, shoulders and back. Some newborns also have enlarged sebaceous glands appearing as small white dots on the face called milia. Both of these characteristics are normal and will disappear after a few ...

  18. Petrophysical Characteristics of Impaktites

    NASA Astrophysics Data System (ADS)

    Mayr, S. I.; Popov, Yu.

    2015-09-01

    We give examples of petrophysical characteristics of Impactites. We differ between impact breccia and impact melt rocks, and shocked & displaced target rocks. We use our datasets obtained from Puchezh-Katunki, Ries, Chicxulub and Chesapeake.

  19. Onboard Navigation Systems Characteristics

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The space shuttle onboard navigation systems characteristics are described. A standard source of equations and numerical data for use in error analyses and mission simulations related to space shuttle development is reported. The sensor characteristics described are used for shuttle onboard navigation performance assessment. The use of complete models in the studies depend on the analyses to be performed, the capabilities of the computer programs, and the availability of computer resources.

  20. Housing characteristics 1993

    SciTech Connect

    1995-06-01

    This report, Housing Characteristics 1993, presents statistics about the energy-related characteristics of US households. These data were collected in the 1993 Residential Energy Consumption Survey (RECS) -- the ninth in a series of nationwide energy consumption surveys conducted since 1978 by the Energy Information Administration of the US Department of Energy. Over 7 thousand households were surveyed, representing 97 million households nationwide. A second report, to be released in late 1995, will present statistics on residential energy consumption and expenditures.

  1. Characteristics of intuitive nurses.

    PubMed

    Miller, V G

    1995-06-01

    A description is provided of the process used to verify characteristics of intuitive nurses that had been reported in the literature. These characteristics supplied the framework for construction of the Miller Intuitiveness Instrument (MII) reported earlier (Miller, 1993). Evidence for validity of the MII was provided in the Miller (1993) study by examining factor analyses and correlations with the intuitive component of the Myers-Briggs Type Indicator (MBTI). The following characteristics were subsequently verified: Intuitive nurses are willing to act on their intuitions, are skilled clinicians, and incorporate a spiritual component in their practices. In addition, intuitive nurses express an interest in the abstract nature of things and are risk takers. Intuitive nurses prefer intuition to sensing (as reflected by the MBTI) as a way to take in information. They are extroverted and express confidence in their intuitions. Likewise, nurses who delay making decisions until all the information is in are more intuitive than those who make decisions abruptly.

  2. Phenomenal characteristics of cryptomnesia.

    PubMed

    Brédart, Serge; Lampinen, James M; Defeldre, Anne-Catherine

    2003-01-01

    Qualitative characteristics of cryptomnesia, or unintentional plagiarism were investigated. In Experiment 1 we compared accurate and inaccurate source attributions in terms of their level of confidence using instructions that did not require a fixed number of responses. Confidence was lower for plagiarised responses than for correct responses. Nevertheless, participants provided high ratings of certainty for a large proportion of their plagiarised responses. In Experiment 2 the phenomenological differences between plagiarised recall and veridical recall were compared by using an adaptation of the memory characteristics questionnaire (Johnson, Foley, Suengas, & Raye, 1988). Correct responses were associated with more experiential detail than plagiarised responses. However, a considerable number of plagiarised responses were accompanied by a confident memory of at least one qualitative characteristic. Results are discussed in terms of the source monitoring framework developed by Johnson, Hashtroudi, and Lindsay (1993).

  3. Commercial Buildings Characteristics, 1992

    SciTech Connect

    Not Available

    1994-04-29

    Commercial Buildings Characteristics 1992 presents statistics about the number, type, and size of commercial buildings in the United States as well as their energy-related characteristics. These data are collected in the Commercial Buildings Energy Consumption Survey (CBECS), a national survey of buildings in the commercial sector. The 1992 CBECS is the fifth in a series conducted since 1979 by the Energy Information Administration. Approximately 6,600 commercial buildings were surveyed, representing the characteristics and energy consumption of 4.8 million commercial buildings and 67.9 billion square feet of commercial floorspace nationwide. Overall, the amount of commercial floorspace in the United States increased an average of 2.4 percent annually between 1989 and 1992, while the number of commercial buildings increased an average of 2.0 percent annually.

  4. Watershed geomorphological characteristics

    USGS Publications Warehouse

    Fitzpatrick, Faith

    2016-01-01

    This chapter describes commonly used geomorphological characteristics that are useful for analyzing watershed-scale hydrology and sediment dynamics. It includes calculations and measurements for stream network features and areal basin characteristics that cover a range of spatial and temporal scales and dimensions of watersheds. Construction and application of longitudinal profiles are described in terms of understanding the three-dimensional development of stream networks. A brief discussion of outstanding problems and directions for future work, particularly as they relate to water-resources management, is provided. Notations with preferred units are given.

  5. Personality Characteristics of Engineers

    ERIC Educational Resources Information Center

    van der Molen, Henk T.; Schmidt, Henk G.; Kruisman, Gerard

    2007-01-01

    The objective of the current study was to investigate the personality characteristics of a group of engineers with a variety of years of experience. It was executed to remedy shortcomings of the literature concerning this issue and to produce suggestions for a postgraduate training programme for engineers. A total of 103 engineers were tested with…

  6. Gender and Learner Characteristics

    ERIC Educational Resources Information Center

    Hindal, Huda; Reid, Norman; Whitehead, Rex

    2013-01-01

    It is well established that girls and boys perform differently in traditional examinations in most countries. This study looks at a sample of 754 school students in Kuwait (aged about 13) and explores how boys and girls differ in the performance in a range of tests related to learner characteristics. The fundamental question is how boys and girls…

  7. Characteristics of Excellent Principals.

    ERIC Educational Resources Information Center

    Batsis, Thomas M.

    Recent business and education publications have stressed the excellence concept and the pivotal role of the executive. While effective business leaders are thought to possess certain characteristics, no consensus exists concerning educational leaders' roles. Although instructional leadership has received most attention in education literature,…

  8. Personality Characteristics of Engineers

    ERIC Educational Resources Information Center

    van der Molen, Henk T.; Schmidt, Henk G.; Kruisman, Gerard

    2007-01-01

    The objective of the current study was to investigate the personality characteristics of a group of engineers with a variety of years of experience. It was executed to remedy shortcomings of the literature concerning this issue and to produce suggestions for a postgraduate training programme for engineers. A total of 103 engineers were tested with…

  9. Characteristics of USB noise

    NASA Technical Reports Server (NTRS)

    Gibson, J. S.; Searle, N.

    1976-01-01

    An extensive series of noise measurements, for a variety of geometric and operational parameters, was made on models of upper surface blowing (USB) powered lift systems. The data obtained were analyzed and the effects and trends of parametric variation defined. The behavior and nature of USB noise and the design of USB systems with low noise characteristics is examined.

  10. Characteristics of Hypermedia Presentations.

    ERIC Educational Resources Information Center

    Lewis, Wiley B.; Jansen, Duane G.

    This paper addresses those characteristics of effective and efficient hypermedia presentations that are important for consideration by educators in developing and/or selecting such presentations. Definitions of hypertext, hypermedia, and multimedia are provided, and the relationships among these terms are described. Four other terms useful to…

  11. Attractors and characteristic exponents

    SciTech Connect

    de Oliveira, C.R.

    1988-11-01

    A natural definition of an attractor as an invariant measure is given (based on the ergodic theory of axiom A diffeomorphisms) and some results are proved which support this definition. It is also proved that if an attractor has every characteristic exponent less than zero in a set of nonzero measure, then the support set of the attractor is an asymptotic stable periodic orbit.

  12. Characteristics of Instructional Technologists

    ERIC Educational Resources Information Center

    Gagne, Robert M.

    1973-01-01

    A report on the important characteristics of instructional technologists which include (1) a belief in empirical evidence as a source of truth and a preferred basis for action; (2) familiarity with theory that relates learning experiences to learning outcomes; and (3) a set of intellectual skills that includes techniques for analyzing and…

  13. Characteristics of Instructional Technologists.

    ERIC Educational Resources Information Center

    Gagne, Robert M.

    A thoroughly planned program for instructional technologists--one including selection, education, and on-the-job training--must take into consideration the competencies and characteristics desirable in such technologists. Such requirements fall into three categories: attitudes or values, specialized knowledge, and intellectual skills or…

  14. Metering Characteristics of Carburetors

    NASA Technical Reports Server (NTRS)

    Tice, Percival S; Dickinson, H C

    1919-01-01

    Report presents the results of an extensive experimental investigation of the performance of different types of carburetors as effecting the maintenance under all conditions of correct ratio between the weights of fuel and air. It also gives a description of the Bureau of Standards carburetor test plant, test equipment and measuring instruments used to determine the metering characteristics of carburetors.

  15. Steering characteristics of motorcycles

    NASA Astrophysics Data System (ADS)

    Fujii, Shigeru; Shiozawa, Souichi; Shinagawa, Akinori; Kishi, Tomoaki

    2012-08-01

    In this study, the results of a steady-state cornering test using a sport-touring motorcycle and the analysis of those test results are presented. This test was conducted as an activity in our efforts to realise a quantitative development method for motorcycles. The measurement data from this test include measurement results for tyre force, tyre moment, and tyre slip angle that have not been practically addressed in the research of motorcycles, in addition to normal measurement results for velocity, steering angle, steering torque, roll angle, etc. Until now research on motorcycle dynamics characteristics has indicated that 'there is a strong relationship between the motorcycle dynamics characteristics and the tyre slip angle'. However, since it is difficult to take highly precise measurements of the motorcycle's tyre slip angle during actual riding, especially when the motorcycle is tilted during cornering, such measurements have been avoided, cf. [H. Ishii and Y. Tezuka, Considerations of turning performance for motorcycle, SETC (1997), pp. 383-389]. Nevertheless, in this research we attempted to measure the tyre slip angle and also attempted to investigate in detail the dynamics characteristics and tyre characteristics during riding. Until now there has not been an adequate investigation conducted under a variety of riding conditions, but it is the aim of this research to show that it is possible to measure the tyre slip angle with a reasonable accuracy. It is our opinion that this will open a new path to a more detailed investigation of the motorcycle's dynamics characteristics. In addition, we conducted measurements using not only the normal rider's lean angle (lean-with posture), but also measurements in the case where the rider's lean angle was intentionally changed, in order to investigate the effects that a change in the rider's posture has on the variation in the measurement results of the motorcycle's dynamics. Furthermore, we then compared these

  16. The wind characteristics program

    NASA Astrophysics Data System (ADS)

    Wendell, L. L.

    Wind characteristics research activities emphasize wind resource assessment, site selection and evaluation techniques, and wind characteristics for wind turbine design, performance and operations evaluation. Wind resource analysis shows the greatest area of high wind power resource is in the midsection of the U.S. High wind power is available in other sections of the country and is described in some detail on a state by state basis in twelve regional atlases. To carry the wind prospecting process to a finer scale, site selection techniques for small and large wind turbines were developed, tested, and documented. There is a broad range of sophistication and reliability in these techniques and their application must be matched with the priorities and time available for energy planning efforts. The nature of wind gustiness was evaluated statistically and modeled for calculating fatigue cycles and extreme events.

  17. Air Superiority Fighter Characteristics.

    DTIC Science & Technology

    1998-06-05

    biographies are useful in garnering airpower advocate theories as well as identifying key characteristics. Air campaign results, starting with World...members, yet weapons and avionics systems grow increasingly more complex. At an airpower symposium in 1977, Air Chief Marshal Sir Frederick Rosier...Grant, 1990. Skinner , Michael and George Hall. Red Flae: Air Combat for the 90s. Osceola, WL: Motorbooks International Publishers & Wholesalers

  18. Advanced turboprop vibratory characteristics

    NASA Technical Reports Server (NTRS)

    Srinivasan, A. V.; Fulton, G. B.

    1984-01-01

    The assembly of SR5 advanced turboprop blades to develop a structural dynamic data base for swept props is reported. Steady state blade deformation under centrifugal loading and vibratory characteristics of the rotor assembly were measured. Vibration was induced through a system of piezoelectric crystals attached to the blades. Data reduction procedures are used to provide deformation, mode shape, and frequencies of the assembly at predetermined speeds.

  19. Characteristics of healthcare wastes

    SciTech Connect

    Diaz, L.F. Eggerth, L.L.; Enkhtsetseg, Sh.; Savage, G.M.

    2008-07-01

    A comprehensive understanding of the quantities and characteristics of the material that needs to be managed is one of the most basic steps in the development of a plan for solid waste management. In this case, the material under consideration is the solid waste generated in healthcare facilities, also known as healthcare waste. Unfortunately, limited reliable information is available in the open literature on the quantities and characteristics of the various types of wastes that are generated in healthcare facilities. Thus, sound management of these wastes, particularly in developing countries, often is problematic. This article provides information on the quantities and properties of healthcare wastes in various types of facilities located in developing countries, as well as in some industrialized countries. Most of the information has been obtained from the open literature, although some information has been collected by the authors and from reports available to the authors. Only data collected within approximately the last 15 years and using prescribed methodologies are presented. The range of hospital waste generation (both infectious and mixed solid waste fractions) varies from 0.016 to 3.23 kg/bed-day. The relatively wide variation is due to the fact that some of the facilities surveyed in Ulaanbaatar include out-patient services and district health clinics; these facilities essentially provide very basic services and thus the quantities of waste generated are relatively small. On the other hand, the reported amount of infectious (clinical, yellow bag) waste varied from 0.01 to 0.65 kg/bed-day. The characteristics of the components of healthcare wastes, such as the bulk density and the calorific value, have substantial variability. This literature review and the associated attempt at a comparative analysis point to the need for worldwide consensus on the terms and characteristics that describe wastes from healthcare facilities. Such a consensus would greatly

  20. Magnesium battery disposal characteristics

    NASA Astrophysics Data System (ADS)

    Soffer, Louis; Atwater, Terrill

    1994-12-01

    This study assesses the disposal characteristics of U.S. Army procured military magnesium batteries under current Resource Conservation and Recovery Act (RCRA) hazardous waste identification regulations administered by the U.S. Environmental Protection Agency. Magnesium batteries were tested at 100, 50, 10 and 0 percent remaining state of charge. Present findings indicate that magnesium batteries with less than 50 percent remaining charge do not exceed the federal regulatory limit of 5.0 mg/L for chromium. All other RCRA contaminates were below regulatory limits at all levels of remaining charge. Assay methods, findings, disposal requirements and design implications are discussed.

  1. Optical characteristics of lightning

    NASA Technical Reports Server (NTRS)

    Goodman, S. J.

    1985-01-01

    A study of the optical characteristics of cloud-to-ground dischargers and how they compare with intracloud flashes was completed. Time resolved optical (7774A) and electric field-change waveforms were measured above clouds from a U2 airplane coincident with ground-based measurements of lightning. The optical pulse trains are studied for within and between flash variability. Specifically, for each flash researchers examine the 10, 50 (full width half maximum), and 90 percent pulse widths; the 10-10, 10-50, 10-90, and 10-peak percent amplitude rise times; the radiances (optical power densities); radiant energy densities; and pulse intervals. The optical pulse characteristics of first strokes, subsequent strokes, the intracloud components of cloud-to-ground flashes and intracloud flashes as viewed from above cloud are shown to exhibit very similar waveshapes, radiances and radiant energy densities. Descriptive statistics on these pulse categories were tabulated for 25 visually confirmed cloud-to-ground flashes (229 optical pulses) and 232 intracloud flashes (3126 optical pulses). A companion study of lightning observations above and below cloud in storms, storm complexes, and mesoscale convective systems has also been completed. Researchers compared the mapping of total lightning activity from above clouds with ground-based measurements and storm evolution. Although the total (IC + CG) lightning activity is the more representative indication of thunderstorm growth and decay, the ground strike data can be used to locate, diagnose, and track storm evolution in a number of instances.

  2. [Nanobacteria--microbiological characteristics].

    PubMed

    Wilk, Iwona; Martirosian, Gayane

    2004-03-03

    We have reviewed recent publications regarding the microbiological characteristic and pathogenicity of a novel infectious agent, the mineral-forming, sterile-filterable, slow-growing Gram-negative Nanobacteria, detected in bovine/human blood, kidney cyst fluid, urine and kidney stones. According to their 16S rDNA structure, nanobacteria belong to the alpha-2 Proteobacteria, subgroup, which includes the Brucella and Bartonella species. Their cell diameter is 0.2-0.5 microm (the smallest known cell-walled bacteria). Their most remarkable characteristic is the formation of carbonate apatite crystals of neutral pH and at physiologic phosphate and calcium concentrations. The extracellular mineralization forms a hard protective shelter for these hardy microorganisms, and enables them to survive conditions of physical stress that would be lethal to most other bacterial species. The Olavi Kajander group (Finland) suggests that the apatite produced by nanobacteria may play a key role in the formation of all kidney stones, by providing a central calcium phosphate deposit around which other crystalline components can collect. Nanobacteria seems to be a causative agent of diseases related to biomineralization processes.

  3. SPI instrumental background characteristics

    NASA Astrophysics Data System (ADS)

    Jean, P.; Vedrenne, G.; Roques, J. P.; Schönfelder, V.; Teegarden, B. J.; von Kienlin, A.; Knödlseder, J.; Wunderer, C.; Skinner, G. K.; Weidenspointner, G.; Attié, D.; Boggs, S.; Caraveo, P.; Cordier, B.; Diehl, R.; Gros, M.; Leleux, P.; Lichti, G. G.; Kalemci, E.; Kiener, J.; Lonjou, V.; Mandrou, P.; Paul, Ph.; Schanne, S.; von Ballmoos, P.

    2003-11-01

    In its space environment the INTEGRAL observatory is subject to an intense irradiation by energetic cosmic-ray particles that leads, via nuclear interactions with the telescope and spacecraft materials, to an important background of false events. In this paper we present the characteristics of the instrumental background that is observed in the spectrometer SPI (SPectrometer of INTEGRAL). We explain the tuning that has been performed on the parameters of the anticoincidence system in order to optimise the telescope sensitivity over the full energy range. Temporal variations of the instrumental background are discussed and methods are proposed that allow for their modelling in first order. Based on observations with INTEGRAL, an ESA project with instruments and science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, Spain), Czech Republic and Poland, and with the participation of Russia and the USA.

  4. Wafer characteristics via reflectometry

    DOEpatents

    Sopori, Bhushan L.

    2010-10-19

    Various exemplary methods (800, 900, 1000, 1100) are directed to determining wafer thickness and/or wafer surface characteristics. An exemplary method (900) includes measuring reflectance of a wafer and comparing the measured reflectance to a calculated reflectance or a reflectance stored in a database. Another exemplary method (800) includes positioning a wafer on a reflecting support to extend a reflectance range. An exemplary device (200) has an input (210), analysis modules (222-228) and optionally a database (230). Various exemplary reflectometer chambers (1300, 1400) include radiation sources positioned at a first altitudinal angle (1308, 1408) and at a second altitudinal angle (1312, 1412). An exemplary method includes selecting radiation sources positioned at various altitudinal angles. An exemplary element (1650, 1850) includes a first aperture (1654, 1854) and a second aperture (1658, 1858) that can transmit reflected radiation to a fiber and an imager, respectfully.

  5. Three Characteristics of Effective Teachers

    ERIC Educational Resources Information Center

    Steele, Natalie A.

    2010-01-01

    This article discusses three characteristics that are often associated with successful music educators. The three characteristics discussed include nonverbal communication, teacher self-efficacy, and servant leadership. Although there is no magical combination of characteristics that will produce an effective music teacher, these three attributes…

  6. Characteristics of a Healthy Family.

    ERIC Educational Resources Information Center

    Lin, Phylis Lan

    The reason for studying the characteristics of a healthy family is to encourage and strengthen the family and to move toward an enriched family life by using the characteristics as bench marks. Six characteristics are discussed as the essence of a healthy family: (1) commitment; (2) togetherness; (3) appreciation; (4) good communication; (5)…

  7. Three Characteristics of Effective Teachers

    ERIC Educational Resources Information Center

    Steele, Natalie A.

    2010-01-01

    This article discusses three characteristics that are often associated with successful music educators. The three characteristics discussed include nonverbal communication, teacher self-efficacy, and servant leadership. Although there is no magical combination of characteristics that will produce an effective music teacher, these three attributes…

  8. Teacher Retention: Teacher Characteristics, School Characteristics, Organizational Characteristics, and Teacher Efficacy

    ERIC Educational Resources Information Center

    Hughes, Gail D.

    2012-01-01

    The researcher utilized block-entry regression analysis to determine the impacts of teacher characteristics, school characteristics, organizational characteristics, and teacher efficacy on retention in teaching from 782 teacher surveys. Findings indicated that 83.50% of participants planned to teach until retirement. Wald statistics indicated that…

  9. Sensor Characteristics Reference Guide

    SciTech Connect

    Cree, Johnathan V.; Dansu, A.; Fuhr, P.; Lanzisera, Steven M.; McIntyre, T.; Muehleisen, Ralph T.; Starke, M.; Banerjee, Pranab; Kuruganti, T.; Castello, C.

    2013-04-01

    The Buildings Technologies Office (BTO), within the U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy (EERE), is initiating a new program in Sensor and Controls. The vision of this program is: • Buildings operating automatically and continuously at peak energy efficiency over their lifetimes and interoperating effectively with the electric power grid. • Buildings that are self-configuring, self-commissioning, self-learning, self-diagnosing, self-healing, and self-transacting to enable continuous peak performance. • Lower overall building operating costs and higher asset valuation. The overarching goal is to capture 30% energy savings by enhanced management of energy consuming assets and systems through development of cost-effective sensors and controls. One step in achieving this vision is the publication of this Sensor Characteristics Reference Guide. The purpose of the guide is to inform building owners and operators of the current status, capabilities, and limitations of sensor technologies. It is hoped that this guide will aid in the design and procurement process and result in successful implementation of building sensor and control systems. DOE will also use this guide to identify research priorities, develop future specifications for potential market adoption, and provide market clarity through unbiased information

  10. Restructured Freedom configuration characteristics

    NASA Technical Reports Server (NTRS)

    Troutman, Patrick A.; Heck, Michael L.; Kumar, Renjith R.; Mazanek, Daniel D.

    1991-01-01

    In Jan. 1991, the LaRc SSFO performed an assessment of the configuration characteristics of the proposed pre-integrated Space Station Freedom (SSF) concept. Of particular concern was the relationship of solar array operation and orientation with respect to spacecraft controllability. For the man-tended configuration (MTC), it was determined that torque equilibrium attitude (TEA) seeking Control Moment Gyroscope (CMG) control laws could not always maintain attitude. The control problems occurred when the solar arrays were tracking the sun to produce full power while flying in an arrow or gravity gradient flight mode. The large solar array articulations that sometimes result from having the functions of the alpha and beta joints reversed on MTC induced large product of inertia changes that can invalidate the control system gains during an orbit. Several modified sun tracking techniques were evaluated with respect to producing a controllable configuration requiring no modifications to the CMG control algorithms. Another assessment involved the permanently manned configuration (PMC) which has a third asymmetric PV unit on one side of the transverse boom. Recommendations include constraining alpha rotations for MTC in the arrow and gravity gradient flight modes and perhaps developing new non-TEA seeking control laws. Recommendations for PMC include raising the operational altitude and moving to a symmetric configuration as soon as possible.

  11. Exploring Lightning Jump Characteristics

    NASA Technical Reports Server (NTRS)

    Chronis, Themis; Carey, Larry D.; Schultz, Christopher J.; Schultz, Elise; Calhoun, Kristin; Goodman, Steven J.

    2014-01-01

    This study is concerned with the characteristics of storms exhibiting an abrupt temporal increase in the total lightning flash rate (i.e., lightning jump, LJ). An automated storm tracking method is used to identify storm "clusters" and total lightning activity from three different lightning detection systems over Oklahoma, northern Alabama and Washington, D.C. On average and for different employed thresholds, the clusters that encompass at least one LJ (LJ1) last longer, relate to higher Maximum Expected Size of Hail, Vertical Integrated Liquid and lightning flash rates (area-normalized) than the clusters that did not exhibit any LJ (LJ0). The respective mean values for LJ1 (LJ0) clusters are 80 min (35 min), 14 mm (8 mm), 25 kg per square meter (18 kg per square meter) and 0.05 flash per min per square kilometer (0.01 flash per min per square kilometer). Furthermore, the LJ1 clusters are also characterized by slower decaying autocorrelation functions, a result that implies a less "random" behavior in the temporal flash rate evolution. In addition, the temporal occurrence of the last LJ provides an estimate of the time remaining to the storm's dissipation. Depending of the LJ strength (i.e., varying thresholds), these values typically range between 20-60 min, with stronger jumps indicating more time until storm decay. This study's results support the hypothesis that the LJ is a proxy for the storm's kinematic and microphysical state rather than a coincidental value.

  12. Characteristics of Pulsating Aurora

    NASA Astrophysics Data System (ADS)

    Humberset, B. K.; Gjerloev, J. W.; Mann, I. R.; Samara, M.; Michell, R.

    2013-12-01

    We have investigated the spatiotemporal characteristics of pulsating auroral patches observed with an all-sky imager located at Poker Flat, Alaska. Pulsating aurora often covers the entire sky with intermixed large and small-scale patches that vary in intensity or disappear and reappear on different time scales and timings. The broad definition of pulsating aurora covers patches and bands from tens to several tens of km which have a quasi-periodic temporal variation from 1 s to tens of seconds. In this paper we examine >15 patches from different events. We analyze all-sky movies (557.7 nm, 3.31 Hz) with a simple, yet robust, technique that allows us to determine the scale size dependent variability of the >15 individual patches. A spatial 2D Fourier Transform is used to separate the aurora into different horizontal scale sizes, and by correlating each patch for all image separations and available scale sizes smaller than the patch itself, we reveal what scale sizes are pulsating and their variability. The patches are found to be persistent, meaning that we can follow them for typically 5 minutes. The period of the pulsations is often remarkably variable and it seems that only certain scale sizes pulsate (typically the size of the patch). The patches drift with the background ExB plasma drift indicating that the magnetospheric source mechanism drifts with the field lines.

  13. [Cocaine - Characteristics and addiction].

    PubMed

    Girczys-Połedniok, Katarzyna; Pudlo, Robert; Jarząb, Magdalena; Szymlak, Agnieszka

    Cocaine use leads to health, social and legal problems. The aim of this paper is to discuss cocaine action, addicts characteristics, use patterns and consequences, as well as addiction treatment methods. A literature review was based on the Medline, PubMed, Polish Medical Bibliography databases and the Silesian Library resources. The Police and Central Statistical Office statistics, as well as the World Health Organization, the European Monitoring Centre for Drugs and Drug Addiction and the National Office for Combating Drug Addiction reports were used. Cocaine leads to mood improvement, appetite decrease, physical and intellectual activity enhancement, euphoria, inflated self-esteem, social networking ease and increased sexual desire. Cocaine hydrochloride is mainly used intranasaly, but also as intravenous and subcutaneous injections. Cocaine use and first addiction treatment fall in later age compared to other psychoactive substances. There is a high men to women ratio among addicts. There is a relationship between cocaine addiction, the presence of other disorders and genetic predisposition to addiction development. Polish reports indicate higher popularity of cocaine among people with a high economic and social status. Although Poland is a country with the low percentage of cocaine use, its popularity is growing. The consequences of cocaine use concern somatic and mental health problems, socioeconomic and legal conditions. The drug plays a role in crimes and traffic accidents. Because of the risks associated with cocaine use, it has been listed in a register of drugs attached to the Act on Counteracting Drug Addiction. Addiction treatment includes psychological, pharmacological and harm reduction strategies. Med Pr 2016;67(4):537-544. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  14. Characteristics Data Base

    SciTech Connect

    Lewis, E.D.; Moore, R.S. )

    1990-08-01

    The LWR Serial Numbers Database System (SNDB) contains detailed data about individual, historically discharged LWR spent fuel assemblies. This data includes the reactor where used, the year the assemblies were discharged, the pool where they are currently stored, assembly type, burnup, weight, enrichment, and an estimate of their radiological properties. This information is distributed on floppy disks to users in the nuclear industry to assist in planning for the permanent nuclear waste repository. This document describes the design and development of the SNDB. It provides a complete description of the file structures and an outline of the major code modules. It serves as a reference for a programmer maintaining the system, or for others interested in the technical detail of this database. This is the initial version of the SNDB. It contains historical data through December 31, 1987, obtained from the Energy Information Administration (EIA). EIA obtains the data from the utility companies via the RW-859 Survey Form. It evaluates and standardizes the data and distributes the resulting batch level database as a large file on magnetic tape. The Characteristics Data Base obtains this database for use in the LWR Quantities Data Base. Additionally, the CDB obtains the individual assembly level detail from EIA for use in the SNDB. While the Quantities Data Base retains only the level of detail necessary for its reporting, the SNDB does retain and use the batch level data to assist in the identification of a particular assembly serial number. We expect to update the SNDB on an annual basis, as new historical data becomes available.

  15. Pharmacological characteristics of metamizole.

    PubMed

    Jasiecka, A; Maślanka, T; Jaroszewski, J J

    2014-01-01

    Metamizole (dipyrone) is a popular analgetic, non-opioid drug, commonly used in human and veterinary medicine. In some cases, this agent is still incorrectly classified as a non-steroidal anti-inflammatory drug (NSAID). Metamizole is a pro-drug, which spontaneously breaks down after oral administration to structurally related pyrazolone compounds. Apart from its analgesic effect, the medication is an antipyretic and spasmolytic agent. The mechanism responsible for the analgesic effect is a complex one, and most probably rests on the inhibition of a central cyclooxygenase-3 and activation of the opioidergic system and cannabinoid system. Metamizole can block both PG-dependent and PG-independent pathways of fever induced by LPS, which suggests that this drug has a profile of antipyretic action distinctly different from that of NSAIDs. The mechanism responsible for the spasmolytic effect of metamizole is associated with the inhibited release of intracellular Ca2+ as a result of the reduced synthesis of inositol phosphate. Metamizole is predominantly applied in the therapy of pain of different etiology, of spastic conditions, especially affecting the digestive tract, and of fever refractory to other treatments. Co-administration of morphine and metamizole produces superadditive, antinociceptive effects. Metamizole is a relatively safe pharmaceutical preparation although it is not completely free from undesirable effects. Among these side-effects, the most serious one that raises most controversy is the myelotoxic effect. It seems that in the past the risk of metamizole-induced agranulocytosis was exaggerated. Despite the evidence showing no risk of teratogenic and embryotoxic effects, the drug must not be administered to pregnant women, although it is allowed to be given to pregnant and lactating animals. This paper seeks to describe the characteristics of metamizole in the light of current knowledge.

  16. Residential-appliance load characteristics

    NASA Astrophysics Data System (ADS)

    Kohler, J.

    1982-04-01

    The performance of residential photovoltaic systems in combination with energy efficient appliances is examined. The load characteristics are presented for several types of major residential appliances. Load characteristics consist of the average energy use of each appliance, the power demand while the appliance is operating, and a typical use schedule. Potential energy conserving features are investigated for each appliance and used to identify a best available model and maximum feasible energy efficient appliance. Load characteristics of these energy conserving designs are then compared with the load characteristics of a standard model. The feasibility of converting appliances to dc power for use with photovoltaic systems is also discussed.

  17. Intraocular lens power calculation for humanitarian missions based on partial biometry.

    PubMed

    Schmitz, Joseph W; Davis, Kimberly D; McClatchey, Scott K

    2012-07-01

    To determine whether the correlation between corneal power (K) and axial length (AL) can be used for intraocular lens (IOL) power calculation when biometric data are incomplete. Developing regions served by United States Navy humanitarian assistance missions. Case series. Measurements of K and AL were collected from all adult cataract surgery charts and used to calculate emmetropic IOL powers. A formula for estimating K or AL was derived by Deming regression analysis. The emmetropic IOL powers were calculated by hypothetical scenarios as follows: (1) K estimated from the formula and measured AL, (2) mean population K and measured AL, (3) measured K and estimated AL, and (4) measured K and mean population AL. The mean absolute refractive error (MAE) was calculated for each hypothetical scenario and an additional scenario (scenario 5) using single IOL power for all eyes. The MAEs were compared with a paired t test. The formula derived from Deming regression analysis was K = 74.56 - 1.317 × AL. The MAE for the scenarios were (1) 0.90 diopters (D), (2) 1.11 D, (3) 1.91 D, (4) 1.55 D, and (5) 1.22 D. The MAE for scenario 1 was significantly less (P<.01) than that for scenarios 2 and 5. The MAE for scenario 5 was significantly less than that for scenarios 3 and 4. The correlation between K and AL can be used to improve accuracy of IOL calculation when K is unavailable. When the AL is unavailable, the mean population IOL power is most accurate. No author has a financial or proprietary interest in any material or method mentioned. Published by Elsevier Inc.

  18. Metal contents in Centaurium erythraea and its biometry at various levels of environmental pollution.

    PubMed

    Brudzińska-Kosior, Anna; Kosior, Grzegorz; Samecka-Cymerman, Aleksandra; Kolon, Krzysztof; Mróz, Lucyna; Kempers, Alexander J

    2012-06-01

    In this investigation we focus on the influence of pollution on concentration of elements in the medicinal Centaurium erythraea. This herb is collected from wild populations and also provides important information as monitor of environmental quality. Concentrations of Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, N, Ni, P, Pb, V and Zn in Centaurium erythraea and in the soil in which this plant grew were measured together with biometrical features of the species from sites affected by various levels of pollution. C. erythraea from sites polluted by lignite mining and industrial combustion had the highest concentrations of Cd, Co and Zn (principal component and classification analysis, PCCA). C. erythraea from sites influenced by ferrous-chromium and thermal power plants had the highest concentrations of Cr and Fe as well as Cu, Mn and Ni and the highest length of shoots and number of leaves, shoots, nodes, flowers and flowers on the main shoot. These luxurious growth forms were probably related to the highest concentrations of N, P and Fe in the soil and concentrations of N and K accumulated by C. erythraea on these sites as revealed by the established models. Controlling the collection of C. erythraea for medicinal purposes is recommended as this species is able to accumulate increased levels of metals from polluted sites. The medical quality of C. erythraea may be negatively related to the degree and type of pollution of the environment and should not be based on the luxurious growth of individuals which may contain hazardous levels of metals.

  19. Age, gender, biometry, refractive error, and the anterior chamber angle among Alaskan Eskimos.

    PubMed

    Wojciechowski, Robert; Congdon, Nathan; Anninger, William; Teo Broman, Aimee

    2003-02-01

    The prevalence of angle-closure glaucoma (ACG) is greater for Eskimos/Inuit than it is for any other ethnic group in the world. Although it has been suggested that this prevalence may be due to a population tendency toward shallower anterior chamber angles, available evidence for other populations such as Chinese with high rates of ACG has not consistently demonstrated such a tendency. A reticule, slit-lamp, and standard Goldmann one-mirror goniolens were used to make measurements in the anterior chamber (AC) angle according to a previously reported protocol for biometric gonioscopy (BG) (Ophthalmology 1999;106:2161-7). Measurements were made in all four quadrants of one eye among 133 phakic Alaskan Eskimos aged 40 years and older. Automatic refraction, dilated examination of the anterior segment and optic nerve, and A-scan measurements of AC depth, lens thickness, and axial length were also carried out for all subjects. Both central and peripheral AC measurements for the Eskimo subjects were significantly lower than those previously reported by us for Chinese, blacks, and whites under the identical protocol. Eskimos also seemed to have somewhat more hyperopia. There were no differences in biometric measurements between men and women in this Eskimo population. Angle measurements by BG seemed to decline more rapidly over life among Eskimos and Chinese than blacks or whites. Although there was a significant apparent decrease in AC depth, increase in lens thickness, and increase in hyperopia with age among Eskimos, all of these trends seemed to reverse in the seventh decade and beyond. Eskimos do seem to have shallower ACs than do other racial groups. Measurements of the AC angle seem to decline more rapidly over life among Eskimos than among blacks or whites, a phenomenon also observed by us among Chinese, another group with high ACG prevalence. This apparent more rapid decline may be due to a cohort effect with higher prevalence of myopia and resulting wider angles among younger Eskimos and Chinese.

  20. [Analysis of productivity, quality and cost of first grade laboratories: blood biometry].

    PubMed

    Avila, L; Hernández, P; Cruz, A; Zurita, B; Terres, A M; Cruz, C

    1999-04-01

    Assessment of productivity, quality and production costs and determination of the efficiency of top grade clinical laboratories in Mexico. Ten laboratories were selected from among the total number (52) existing in Mexico City, and the Donabedian model of structure, process and results were applied. Blood count was selected as a tracer. The principal problems found were: inadequate distribution of trained human resources, poor glass material, inadequate analytic process and low productivity. These factors are reflected in the unit costs, which exceed reference laboratory costs by 200%. Only 50% of the laboratories analyzed generate reliable results. Only 20% of the laboratories studied operate efficiently. To solve the problems identified requires integral strategies at different levels. A specific recomendation for the improvement of quality and productivity is an assessment of the cost/benefit of creating a central laboratory and using the remaining sites exclusively for the collection of samples.

  1. Biometry and phenology of two sibling Phylloscopus warblers on their circum-Mediterranean migrations

    PubMed Central

    Zduniak, Piotr; Yosef, Reuven; Bensusan, Keith J.; Perez, Charles E.; Tryjanowski, Piotr

    2015-01-01

    Abstract The Mediterranean Sea is known as an ecological barrier for numerous migratory birds flying from European breeding grounds to African wintering sites. Birds generally avoid migration over open sea and fly over land. In the Mediterranean Basin, few land bridges or bottlenecks for migratory birds exist. The narrowest are at the western and eastern extremes: the Strait of Gibraltar and Israel. Comparative studies between these locations are extremely rare to date. Therefore, in order to elucidate the differences between the two flyways, we compared data collected simultaneously for two sister leaf warbler species, the Bonelli’s Warbler complex, Phylloscopus bonelli and Phylloscopus orientalis, at ringing stations in the western Mediterranean Basin Gibraltar, and the eastern Eilat, Israel. Data on biometrics and passage dates of individuals trapped at Gibraltar and Eilat were used, and it was found that mean arrival date of Western Bonelli’s Warblers at Gibraltar was 15 days later than Eastern Bonelli’s Warblers at Eilat. Furthermore, Western Bonelli’s Warblers had shorter wings than Eastern Bonelli’s Warblers. On the other hand, birds in Eilat were in poorer body condition than individuals in Gibraltar. The comparison between geographically distant stop-over sites contributes to furthering our understanding of the development of migration strategies across ecological barriers in sibling species. Our study showed that populations that breed in southwestern Europe migrate through Gibraltar and winter in West Africa are able to accomplish migration in comparatively good body condition. This is in contrast to those that winter in East Africa, migrate through Israel and have to endure the combined challenge of crossing the Sahel, Sahara and Sinai deserts before reaching their breeding grounds across southeast Europe and southwest Asia. Hence, the discrepancies described between the western and the eastern flyway suggest that individuals in the west, in general, migrate shorter distances, have a physiologically less demanding crossing of the North African deserts and appear to stage before their crossing the Strait of Gibraltar, a privilege unavailable to the migrants of the eastern flyway. PMID:26692801

  2. Measurement of anterior chamber diameter and biometry of anterior segment by Scheimpflug slitlamp photography

    SciTech Connect

    Lerman, S.; Hockwin, O.

    1985-03-01

    Twenty-eight fresh donor eyes (Georgia Lions Eye Bank) ranging in age from four months to 87 years were used for an in vitro study to determine the feasibility of obtaining accurate anterior chamber diameter measurements with our Scheimpflug ultraviolet-visible slitlamp densitography apparatus. The in vivo study was performed on 16 hybrid monkeys (of varying age). These data were within 0.1 mm of measurements obtained with a modified paracentesis needle specially designed to obtain such measurements. The results of the foregoing study demonstrate that the Scheimpflug slitlamp photographic analyses can provide an accurate measurement of the anterior chamber diameter without entering the globe surgically. This will enable the surgeon to determine the diameter and order an anterior chamber IOL of a specified size prior to surgery. The authors have devised an automated program to analyze the negatives and provide direct anterior chamber diameter measurements.

  3. Relationships between fetal biometry, maternal factors and birth weight of purebred domestic cat kittens.

    PubMed

    Gatel, L; Rosset, E; Chalvet-Monfray, K; Buff, S; Rault, D N

    2011-12-01

    The goal of this study was to evaluate the relation between kittens' birth weights and biometrical factors from the kittens and the mother during pregnancy. Knowing fetal birth weight could help in detecting abnormalities before parturition. A Caesarean-section or a postnatal management plan could be scheduled. Consequently, the neonatal mortality rate should be decreased. We used ultrasonographic measurements of femur length (FL) or fetal biparietal diameter (BPD), pregnancies, and maternal factors to obtain a model of prediction. For this purpose, linear mixed-effects models were used because of random effects (several fetuses for one queen and a few paired measurements) and fixed effects (litter size, pregnancy rank, weight, wither height, and age of the queen). This study was performed in 24 purebred queens with normal pregnancies and normal body conditions. Queens were scanned in the second half of pregnancy, using a micro-convex probe. They gave birth to 140 healthy kittens whose mean birth weight was 104 g (ranged 65 to 165 g). No correlation between the birth weight and the age of the queen, as a maternal factor alone, was observed. But the birth weight was found to be inversely proportional to the pregnancy rank and the litter size. Moreover, birth weight increased when the weight and wither height of queen increased. BPD and FL increased linearly during pregnancy so a model was used to estimate mean birth weight. Using this model, we found a correlation between mean birth weights and an association of parameters: maternal factors (wither height and age), and litter size.

  4. Sonographic Biometry of Normal Kidney Dimensions among School-age Children in Nsukka, Southeast Nigeria

    PubMed Central

    Eze, CU; Agwu, KK; Ezeasor, DN; Agwuna, KK; Aronu, AE; Mba, EI

    2014-01-01

    Background: Some kidney diseases are usually associated with changes in kidney size. Objective: To determine sonographically the normal limits and percentile curves of the kidney dimensions according to age, gender and somatometric parameters among school-age children. Methods: A prospective cross-sectional research design and convenience sampling method were utilized. Participants included 947 normal subjects (496 boys and 451 girls) aged 6–17 years old. The sonographic examination was performed on a Shenzhen DP-1100 machine with 3.5 MHz convex transducer. Longitudinal and transverse dimensions of the kidneys were obtained in coronal plane with the subject in the supine or left lateral decubitus position. Results: The means of right and left kidney lengths in mm were 79.6 ± 8.1 and 81.6 ± 8.3, respectively while those of the right and left kidney widths in mm were 35.03 ± 3.6 and 35.09 ± 3.6, respectively. Dimensions of the kidneys were not statistically different in boys and girls (p > 0.05). There was a statistically significant difference between right and left kidney length (p < 0.05). Height correlated best with both kidney lengths. Thus the normal limits, prediction models and percentile curves of kidney lengths were established with respect to height. Conclusion: Sonographic determination of pathologic changes in the size of the kidney necessitates knowing the normal ranges of its length especially with respect to height in school-age children. PMID:25303194

  5. Errors Associated with IOLMaster Biometry as a Function of Internal Ocular Dimensions

    PubMed Central

    Faria-Ribeiro, Miguel; Lopes-Ferreira, Daniela; López-Gil, Norberto; Jorge, Jorge; González-Méijome, José Manuel

    2014-01-01

    Purpose To evaluate the error in the estimation of axial length (AL) with the IOLMaster partial coherence interferometry (PCI) biometer and obtain a correction factor that varies as a function of AL and crystalline lens thickness (LT). Methods Optical simulations were produced for theoretical eyes using Zemax-EE software. Thirty-three combinations including eleven different AL (from 20 mm to 30 mm in 1 mm steps) and three different LT (3.6 mm, 4.2 mm and 4.8 mm) were used. Errors were obtained comparing the AL measured for a constant equivalent refractive index of 1.3549 and for the actual combinations of indices and intra-ocular dimensions of LT and AL in each model eye. Results In the range from 20 mm to 30 mm AL and 3.6–4.8 mm LT, the instrument measurements yielded an error between −0.043 mm and +0.089 mm. Regression analyses for the three LT condition were combined in order to derive a correction factor as a function of the instrument measured AL for each combination of AL and LT in the theoretical eye. Conclusions The assumption of a single “average” refractive index in the estimation of AL by the IOLMaster PCI biometer only induces very small errors in a wide range of combinations of ocular dimensions. Even so, the accurate estimation of those errors may help to improve accuracy of intra-ocular lens calculations through exact ray tracing, particularly in longer eyes and eyes with thicker or thinner crystalline lenses. PMID:24766863

  6. Biometry of stomata in Blechnum species (Blechnaceae) with some taxonomic and ecological implications for the ferns.

    PubMed

    Gabriel y Galán, José María; Prada, Carmen; Rolleri, Cristina H; Lahoz-Beltrá, Rafael; Martínez-Calvo, Cristina

    2011-03-01

    Morphological stomatal traits, such as size, form and frequency, have been subject of much literature, including their relationships with environmental factors. However, little effort have focused on ferns, and very few in the genus Blechnum. Stomatal length, width and frequency (as stomatal index) of a number of specimens of fourteen Neotropical species of Blechnum were measured in adult pinnae. The aim of the work was to find biometrical relationships between stomatal traits and between stomatal traits and habit, habitat and ecosystem of the plants. Statistical analyses of data were conducted using Exploratory Data Analysis and Multivariate Statistical Methods. Stomatal length and width showed a very high correlation, suggesting an endogenous, genetic control, thus giving these traits a considerable diagnostic utility. With respect to the relationships between stomatal traits and environment, we found significant statistical relationships between altitude and stomatal index. We also addressed the interpretation of the ecological-selective significance of various assemblages of stomatal traits in a diverse conjunction of habits, habitats and ecosystems.

  7. Accuracy of optical biometry combined with Placido disc corneal topography for intraocular lens power calculation

    PubMed Central

    Savini, Giacomo; Hoffer, Kenneth J.; Barboni, Piero; Balducci, Nicole; Schiano-Lomoriello, Domenico; Ducoli, Pietro

    2017-01-01

    Purpose To investigate the accuracy of a new optical biometer for intraocular lens (IOL) power calculation in eyes undergoing cataract surgery. Methods Consecutive eyes of patients undergoing cataract surgery with the same IOL model were enrolled in a prospective cohort study. Axial length (AL) and corneal power were measured with an optical biometer based on optical low-coherence interferometry and Placido-disc corneal topography. IOL power was calculated with the Hoffer Q, Holladay 1 and SRK/T formulas. For each formula the lens constant was optimized in retrospect in order to achieve a mean prediction error (PE) of zero (difference between the predicted and the postoperative refraction). Median absolute error (MedAE) and percentage of eyes with PE ±0.50 D were calculated. Results Seventy-four eyes of 74 cataract patients were enrolled. The MedAE was 0.25 D with all formulas. A PE within ±0.50 D was obtained in 89.04% of cases with the Hoffer Q and SRK/T formulas, and in 87.67% of cases with the Holladay 1 formula. Conclusions The optical biometer investigated in the present study provides accurate measurements for IOL power calculation. PMID:28231267

  8. Sonographic Biometry of Fetal Interorbital Distance as a Predictor of Gestational Age in Enugu, Southeast Nigeria.

    PubMed

    Nwadike, U I; Agwu, K K; Eze, C U; Okpala, O C; Onu, A O

    2015-05-13

    The objective of this study was to develop a sonographic technique for the measurement of fetal interorbital distance (IOD) for gestational age (GA) determination and to establish a normogram of IOD for the local population. The fronto-transverse sonographic technique was established as a feasible and reproducible technique for IOD measurement. Two independent and experienced sonographers tested the technique and had a coefficient of variation of 17.64% and 19.72%, respectively, which is statistically insignificant. The established technique was used to measure the IOD of 320 fetuses from the 13(th) week to 40(th) week GA, while standard technique was used to measure biparietal diameter (BPD), head circumference (HC) and femur length (FL) of the fetuses. The data obtained were used to determine the regression equation GA = 6.24 + 4.89 IOD for the prediction of the gestational age. There was good correlation between IOD, BPD, HC and FL. The predicted normogram of IOD was compared with normogram of the Caucasian population. The result showed that there was no statistical difference between them (p < 0.05). Results from the study suggest that the fronto-transverse technique is a feasible and reproducible technique for IOD measurement and the established normogram of IOD can be a veritable statistic for GA prediction in our locality.

  9. Salivary glands of healthy children versus sialorrhea children, is there an anatomical difference? An ultrasonographic biometry.

    PubMed

    Cardona, Isabel; Saint-Martin, Christine; Daniel, Sam J

    2015-05-01

    There is no literature about the average size of the salivary glands in the pediatric population with drooling (sialorrhea). Studies have shown that some pathologies affect the functionality of the salivary glands. We assessed via ultrasonography the sizes of the submandibular and parotid glands in 9 healthy children who were not suffering from local or systemic diseases that could affect the salivary glands. We also compared this group with a group of 9 patients with sialorrhea. Volunteers were matched based on age, gender, and BMI. Body weight did not differ more than 20% from ideal weight. The parotid and submandibular glands of 9 patients with sialorrhea without any previous treatment were measured via ultrasound and matched to a healthy control. Children with various causes for drooling were included (neurological disorders, neuromuscular disorders, lack of oral motor control). Dimensions of the parotid glands in drooling and healthy patients were: surface area 2.96 cm(2) (SD ±0.90) and 2.81 cm(2) (SD ±0.54); in depth 1.68 cm (SD ±0.24) and 1.61 cm (SD ±0.27); in the axis longitudinal to the horizontal mandibular ramus 3.18 cm (±0.46) and 3.15 cm (SD ±0.45) in drooling and healthy groups respectively. The means of submandibular glands of drooling and healthy patients measured in surface area: 3.20 cm(2) (SD ±0.66) and 3.08 cm(2) (SD ±0.65); anterior-posterior length 1.55 cm (SD ±0.23) and 1.46 cm (SD ±0.23), medio-lateral length 3.07 cm (SD ±0.39) and 3.07 cm (SD ±0.32). There was no statistical significance in comparison with the healthy group control. The parotid and submandibular salivary glands in the pediatric population do not differ in size in children with or without drooling. Measuring the glands at baseline and post treatment with botulinum toxin injections allows one to evaluate if there are changes in the gland related to the treatment. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. Ocular biometry in an urban Indian population: the Singapore Indian Eye Study (SINDI).

    PubMed

    Pan, Chen-Wei; Wong, Tien-Yin; Chang, Lan; Lin, Xiao-Yu; Lavanya, Raghavan; Zheng, Ying-Feng; Kok, Yee-Onn; Wu, Ren-Yi; Aung, Tin; Saw, Seang-Mei

    2011-08-22

    PURPOSE. To describe the distribution and determinants of ocular biometric parameters in adult Singapore Indians. METHODS. A population-based, cross-sectional study was conducted on 3400 Indians aged 40 to 83 years residing in Singapore. Ocular components including axial length (AL), anterior chamber depth (ACD), and corneal radius (CR) were measured by partial coherence interferometry. Refraction was recorded in spherical equivalent (SE). RESULTS. After 502 individuals with previous cataract surgery were excluded, ocular biometric data on 2785 adults were analyzed. The mean AL, ACD, and CR were 23.45 ± 1.10, 3.15 ± 0.36, and 7.61 ± 0.26 mm, respectively. The mean AL/CR ratio was 3.08 ± 0.13. The mean AL was 23.53, 23.49, 23.35, and 23.25 mm in 40- to 49-, 50- to 59-, 60- to 69-, and 700 to 83-year age groups, respectively (P < 0.001). Men had significantly longer ALs than women (23.68 mm versus 23.23 mm, P < 0.001). In multivariate linear regression models, AL was found to be longer in adults who were taller (P < 0.001), better educated (University, P < 0.001), and more apt to spend time reading (P < 0.001). Increasing CR was associated with increasing height (P = 0.008). AL was the strongest determinant for refraction in all age groups, whereas lens nuclear opacity was a predictor in adults aged 60 to 83 years. CONCLUSIONS. The AL in Indians living in Singapore was similar to that of Malays in Singapore, but longer than that of Indians living in India. Time spent reading, height, and educational level were the strongest determinants of AL. AL was the strongest predictor of SE in all age groups.

  11. Age, Gender, Biometry, Refractive Error, and the Anterior Chamber Angle among Alaskan Eskimos

    PubMed Central

    Wojciechowski, Robert; Congdon, Nathan; Anninger, William; Broman, Aimee Teo

    2011-01-01

    Background The prevalence of angle-closure glaucoma (ACG) is greater for Eskimos/Inuit than it is for any other ethnic group in the world. Although it has been suggested that this prevalence may be due to a population tendency toward shallower anterior chamber angles, available evidence for other populations such as Chinese with high rates of ACG has not consistently demonstrated such a tendency. Methods A reticule, slit-lamp, and standard Goldmann one-mirror goniolens were used to make measurements in the anterior chamber (AC) angle according to a previously reported protocol for biometric gonioscopy (BG) (Ophthalmology 1999;106:2161–7). Measurements were made in all four quadrants of one eye among 133 phakic Alaskan Eskimos aged 40 years and older. Automatic refraction, dilated examination of the anterior segment and optic nerve, and A-scan measurements of AC depth, lens thickness, and axial length were also carried out for all subjects. Results Both central and peripheral AC measurements for the Eskimo subjects were significantly lower than those previously reported by us for Chinese, blacks, and whites under the identical protocol. Eskimos also seemed to have somewhat more hyperopia. There were no differences in biometric measurements between men and women in this Eskimo population. Angle measurements by BG seemed to decline more rapidly over life among Eskimos and Chinese than blacks or whites. Although there was a significant apparent decrease in AC depth, increase in lens thickness, and increase in hyperopia with age among Eskimos, all of these trends seemed to reverse in the seventh decade and beyond. Conclusions Eskimos do seem to have shallower ACs than do other racial groups. Measurements of the AC angle seem to decline more rapidly over life among Eskimos than among blacks or whites, a phenomenon also observed by us among Chinese, another group with high ACG prevalence. This apparent more rapid decline may be due to a cohort effect with higher prevalence of myopia and resulting wider angles among younger Eskimos and Chinese. PMID:12578783

  12. Anterior segment biometry: a study and review of resolution and repeatability data.

    PubMed

    Reinstein, Dan Z; Gobbe, Marine; Archer, Timothy J

    2012-07-01

    To obtain comparable resolution and repeatability data for a selection of anterior segment imaging devices. A standard letter of request was sent in May 2008 to each device manufacturer requesting resolution and repeatability data for its device to be provided according to specific definitions and protocol; if this was not already published in the peer-reviewed domain, compliant raw data were required. Where applicable, repeatability data were reported for corneal vertex corneal thickness; epithelial and flap thickness; minimum corneal thickness; corneal, epithelial and flap thickness mapping for the central 6-mm diameter; minimum residual stromal thickness; angle-to-angle diameter; sulcus-to-sulcus diameter; and anterior chamber depth. To summarize published repeatability data, a complete review of the peer-reviewed literature waas performed. Nine of the 13 manufacturers contacted agreed to take part and provided the data requested: Pentacam HD (Oculus Optikgeräte GmbH), Galilei (Ziemer), Visante OCT (Carl Zeiss Meditec), SL-OCT (Haag-Streit), RTVue (Optovue), Artemis (ArcScan), Vumax (Sonomed), HiScan (Opticon), and Eye Cubed (Ellex/Innovative). Only one (Carl Zeiss Meditec) of 9 manufacturers was able to provide the data directly upon request, without performing a prospective study. Five of the 9 manufacturers were able to provide a complete set of repeatability data for all parameters measurable with their device; the remaining 4 manufacturers admitted that repeatability of some parameters was unknown. Both literature and manufacturers' data on file were lacking and required the study to be performed. This report provides an imperfect, but most comprehensive to date, resolution and repeatability data review of biometric devices intended for surgical planning. Copyright 2012, SLACK Incorporated.

  13. Evaluation of biometry and corneal astigmatism in cataract surgery patients from Central China.

    PubMed

    Yu, Ji-Guo; Zhong, Jie; Mei, Zhong-Ming; Zhao, Fang; Tao, Na; Xiang, Yi

    2017-04-26

    To evaluate the distribution of biometric parameters and corneal astigmatism using the IOLMaster device before phacoemulsification in cataract patients in Central China. Consecutive cataract patients were recruited at the Central Hospital of Wuhan between January 2015 and June 2016. Ocular axial length (AL), keratometry values, anterior chamber depth (ACD) and horizontal corneal diameter (white to white [WTW]) of each cataract-affected eye were measured with the IOLMaster device. The study evaluated 3209 eyes of 2821 cataract patients. The mean AL, ACD, and WTW were 24.38 ± 2.47 mm, 3.15 ± 0.48 mm, and 11.63 ± 0.43 mm, respectively. Corneal astigmatism of 0.51-1.00 diopters (D) was the most common range of values (34.96%). A total of 10.56% patients exhibited a corneal astigmatism greater than 2.0 D. The flat and steep keratometry values gradually increased with age. The mean ACD and WTW showed increasing trends as the AL increased (P < 0.001). When the AL was shorter than 26.0 mm, the keratometry decreased as AL increased. The against-the-rule (ATR) astigmatism proportion increased with age and the with-the-rule (WTR) astigmatism proportion decreased with age. The profile of ocular biometric data and corneal astigmatism may help ophthalmologists improve their surgical procedures and make an appropriate IOL choice to gain a high quality of postoperative vision.

  14. Relative localizing value of amygdalo-hippocampal MR biometry in temporal lobe epilepsy.

    PubMed

    Gonçalves Pereira, Pedro M; Oliveira, Eduardo; Rosado, Pedro

    2006-05-01

    The aims of the study were (i) to examine the localizing value of three MRI quantitative modalities (qMRI) currently used for the analysis of the hippocampus and amygdala in the context of pre-surgical screening and (ii) to propose a step-by-step protocol based on the sensitivity and performance of the different MR techniques. Ninety-two adults with chronic mesial temporal lobe epilepsy (TLE) of which 28 underwent amygdalo-hippocampal resection, and 34 age-matched controls were included in the study. High-resolution qMRI was performed at 1.5 T, including a tilted T1-weighted 3D-dataset for volumetry and four-echoes T2 relaxometry (both for hippocampus and amygdala quantifications) and multi-voxel spectroscopy [NAA/(Cho+Cre)] (exclusively in the hippocampus). Individual qMRI data were compared with electroencephalography regarding the localization of the epileptogenic area, with the neuropathological data and with postoperative outcome. MRI pathology was defined based on 99% confidence ellipses. Ten controls were used to assess the quantitative MRI intra- and inter-observer variability for all variables. Volumetric measurements revealed unilateral damage in 77% of the patients, T2-relaxometry in 64% and spectroscopy in 53%. Additional measurements of the amygdalae (T2-relaxometry) allowed us to localize pathology that coexists with that of the hippocampus in 34%, and isolated unilateral amygdala damage in 8% of patients. Volumetry and T2-relaxometry (not spectroscopy) were associated with postoperative outcome, but accurate predictive models were computed based on hippocampal measures only. At least at 1-year follow-up, volumetry predicts outcome correctly in 100% of the cases, whilst T2-relaxometry classified 96.4% (27/28) of these patients. All operated patients had hippocampal sclerosis. Hippocampal structural damage is equivocally depicted by spectroscopy. For diagnostic and pre-operative evaluation, hippocampal volumetry and T2-relaxometry provide maximal accuracy. Amygdala quantifications are irrelevant in the pre-operative evaluation but may be useful for diagnostic purposes. Of the three qMRI modalities tested, T2-relaxometry provided the best balance between diagnosis accuracy and time-efficiency to lateralize a sclerotic lesion on the majority of the patients. Cases that remain undecided after T2-relaxometry may benefit from additional measurements based on hippocampal volumetry.

  15. Errors associated with IOLMaster biometry as a function of internal ocular dimensions.

    PubMed

    Faria-Ribeiro, Miguel; Lopes-Ferreira, Daniela; López-Gil, Norberto; Jorge, Jorge; González-Méijome, José Manuel

    2014-01-01

    To evaluate the error in the estimation of axial length (AL) with the IOLMaster partial coherence interferometry (PCI) biometer and obtain a correction factor that varies as a function of AL and crystalline lens thickness (LT). Optical simulations were produced for theoretical eyes using Zemax-EE software. Thirty-three combinations including eleven different AL (from 20mm to 30mm in 1mm steps) and three different LT (3.6mm, 4.2mm and 4.8mm) were used. Errors were obtained comparing the AL measured for a constant equivalent refractive index of 1.3549 and for the actual combinations of indices and intra-ocular dimensions of LT and AL in each model eye. In the range from 20mm to 30mm AL and 3.6-4.8mm LT, the instrument measurements yielded an error between -0.043mm and +0.089mm. Regression analyses for the three LT condition were combined in order to derive a correction factor as a function of the instrument measured AL for each combination of AL and LT in the theoretical eye. The assumption of a single "average" refractive index in the estimation of AL by the IOLMaster PCI biometer only induces very small errors in a wide range of combinations of ocular dimensions. Even so, the accurate estimation of those errors may help to improve accuracy of intra-ocular lens calculations through exact ray tracing, particularly in longer eyes and eyes with thicker or thinner crystalline lenses. Copyright © 2013 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

  16. Eopolydiexodina (Middle Permian giant fusulinids) from Afghanistan: Biometry, morphometry, paleobiogeography, and end-Guadalupian events

    NASA Astrophysics Data System (ADS)

    Colpaert, Clémentine; Monnet, Claude; Vachard, Daniel

    2015-04-01

    The most spectacular macroevolutionary trend presented by the genera of schwagerinoid fusulinids, during the Pennsylvanian -Permian, is an enormous increase in size, which culminated in the Middle Permian with Eopolydiexodina. However, this potential major biogeographic marker, during the Kubergandian-early Midian time interval, is as yet hampered by its poor taxonomic characterization. Hence, Eopolydiexodina is revised here using biometric and morphometric methods applied to large collections from Afghanistan and selected taxa in the literature. These multivariate analyses consist of classical linear test parameters, as well as new area parameters acquired by computer image analysis. The Afghan species are re-defined, and some other species, occasionally described as Cimmerian, are re-discussed. These methods, combined with classical morphological analyses, also permit to conclude that the largest Eopolydiexodina of Afghanistan are microspheric specimens (probably agamonts) of E. afghanensis and E. bithynica. Two megalospheric groups of individuals (probably gamonts and schizonts) are represented in both species, as well as in E. persica and E. darvasica. Due to this presence of gamonts, agamonts and schizonts in several species, Eopolydiexodina is probably the oldest identified trimorphic genus among the large benthic foraminifers. Biostratigraphically, Eopolydiexodina appears restricted to the late Kubergandian to early Midian. The associated Afghan fusulinids (Dunbarula, Kahlerina, Afghanella, Yangchienia, Sumatrina, and Codonofusiella) allow proposing an accurate biostratigraphy of the Eopolydiexodina species in the Murgabian-Midian boundary interval. Paleobiogeographically, Eopolydiexodina was essentially located in the Laurentian and Perigondwanan borders of the Tethys. The possible presence of Eopolydiexodina in the Cimmerian Continent and in some regions of China has never been irrefutably demonstrated. This paleobiological revision of Eopolydiexodina and the biostratigraphic revision of other large Capitanian fusulinids, permit to suggest that the end-Guadalupian event is most probably a protracted succession of last appearance data of giant genera rather than an instantaneous Lilliput effect at the Capitanian/Wuchiapingian boundary.

  17. Ultrasound signal processing for characterization and enhanced biometry of the cornea

    NASA Astrophysics Data System (ADS)

    Silverman, Ronald H.; Reinstein, Dan Z.; Lizzi, Frederick L.; Coleman, D. J.

    2001-05-01

    Purpose: The cornea acts as the window of the eye's optical system, and its chief refractive component. The lack of intervening tissues makes the cornea accessible to very high frequency ultrasonic study. In this report, we detail use of radiofrequency (RF) signal processing methods to characterize corneal pathology and to enhance biometric precision. Methods: Using a 50 MHz PVDF transducer, we scanned the cornea using an arc motion so as to maintain normality and consistent range. RF data were acquired at a sample rate of 500 MHz. Deconvolution against a glass-plate echo allowed biometric enhancement (by effectively broadening the bandwidth) and measurement of tissue backscatter spectra. Results: Calibrated spectrum analysis was used to quantitatively measure backscatter in corneal scars and other pathologies. Signal processing allowed us to attain reproducibility for repeated measurements of the corneal epithelium (approximately 50 microns thick) to 1 micron. By combining measurements from a series of planes, maps of the thickness of the individual layers comprising the cornea were produced. Conclusion: The layers of the cornea have different optical refractive indices, and thus their thicknesses directly affect visual acuity. The scattering of light by a corneal scar is caused by inhomogeneities or irregularities that may result in acoustic backscatter as well. The ability of ultrasound to quantify backscatter and corneal layer thickness provides a new avenue for diagnosis of corneal disease and refractive abnormalities.

  18. Combined laser-ray tracing and OCT system for biometry of the crystalline lens (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Ruggeri, Marco; Maceo Heilman, Bianca M.; Yao, Yue; Chang, Yu-Cherng; Gonzalez, Alex; Rowaan, Cornelis; Mohamed, Ashik; Williams, Siobhan; Durkee, Heather A.; Silgado, Juan; Bernal, Andres; Arrieta-Quintero, Esdras; Ho, Arthur; Parel, Jean-Marie A.; Manns, Fabrice

    2017-02-01

    Age-related changes in the crystalline lens shape and refractive index gradient produce changes in dioptric power and high-order aberrations that influence the optics of the whole eye and contribute to a decrease in overall visual quality. Despite their key role, the changes in lens shape and refractive index gradient with age and accommodation and their effects on high-order aberrations are still not well understood. The goal of this project was to develop a combined laser ray tracing (LRT) and optical coherence tomography (OCT) system to measure high-order aberrations, shape and refractive index gradient in non-human primate and human lenses. A miniature motorized lens stretching system was built to enable imaging and aberrometry of the lens during simulated accommodation. A positioning system was also built to enable on- and off-axis OCT imaging and aberrometry for characterization of the peripheral defocus of the lens. We demonstrated the capability of the LRT-OCT system to produce OCT images and aberration measurements of crystalline lens with age and accommodation in vitro. In future work, the information acquired with the LRT-OCT system will be used to develop an accurate age-dependent lens model to predict the role of the lens in the development of refractive error and aberrations of the whole eye.

  19. Measurement of cervical biometry using transvaginal ultrasonography in predicting preterm labor.

    PubMed

    Tanvir; Ghose, Seetesh; Samal, Sunita; Armugam, Sedhilcoumari; Parida, Pallavee

    2014-07-01

    Preterm delivery is associated with high perinatal mortality and morbidity. Although detection of fetal fibronectin in cervical can predict preterm labor, but it is not available in lower source setting area. So, cervical length measurement by ultrasound can be used as an alternative to fetal fibronectin for predicting preterm labor. To find out the effectiveness of assessment of cervical length by endovaginal ultrasonography in predicting preterm delivery. The study was conducted in the infertility clinic of Mahatma Gandhi Medical College and Research Institute, Pondicherry from January 2010 to July 2011. A total of 130 women with singleton gestation were studied with transvaginal ultrasonography (TVS) to assess the cervical changes (cervical length, dilation of internal os, presence of funneling) between 22 weeks and 24 weeks of gestation. The gestational age at delivery in women with cervical length with ≥25 mm were compared with those of <25 mm. Statistical analysis was done using Chi-square test. The P value is <0.001 which is statistically significant. The mean cervical length in the study population was 33.16 mm. 16 women had cervical length <25 mm at mid trimesters can out of which 13 (40.62%) went for spontaneous preterm delivery. The relative risk of preterm delivery increased as the length of the cervix decreased. The P value is <0.001 which is statistically significant. A significant difference was found between multigravida at risk of preterm being 62.5% compared to primigravida which was 37.5%. The risk of spontaneous preterm delivery is increased in women who are found to have a short cervix by TVS during pregnancy and it is a sensitive, simple and cost effective method of assessing risk of preterm delivery.

  20. Measurement of cervical biometry using transvaginal ultrasonography in predicting preterm labor

    PubMed Central

    Tanvir; Ghose, Seetesh; Samal, Sunita; Armugam, Sedhilcoumari; Parida, Pallavee

    2014-01-01

    Context: Preterm delivery is associated with high perinatal mortality and morbidity. Although detection of fetal fibronectin in cervical can predict preterm labor, but it is not available in lower source setting area. So, cervical length measurement by ultrasound can be used as an alternative to fetal fibronectin for predicting preterm labor. Aims: To find out the effectiveness of assessment of cervical length by endovaginal ultrasonography in predicting preterm delivery. Settings and Design: The study was conducted in the infertility clinic of Mahatma Gandhi Medical College and Research Institute, Pondicherry from January 2010 to July 2011. Materials and Methods: A total of 130 women with singleton gestation were studied with transvaginal ultrasonography (TVS) to assess the cervical changes (cervical length, dilation of internal os, presence of funneling) between 22 weeks and 24 weeks of gestation. The gestational age at delivery in women with cervical length with ≥25 mm were compared with those of <25 mm. Statistical Analysis Used: Statistical analysis was done using Chi-square test. The P value is <0.001 which is statistically significant. Results: The mean cervical length in the study population was 33.16 mm. 16 women had cervical length <25 mm at mid trimesters can out of which 13 (40.62%) went for spontaneous preterm delivery. The relative risk of preterm delivery increased as the length of the cervix decreased. The P value is <0.001 which is statistically significant. A significant difference was found between multigravida at risk of preterm being 62.5% compared to primigravida which was 37.5%. Conclusions: The risk of spontaneous preterm delivery is increased in women who are found to have a short cervix by TVS during pregnancy and it is a sensitive, simple and cost effective method of assessing risk of preterm delivery. PMID:25097417

  1. Keratometry, biometry and prediction of intraocular lens power in the equine eye.

    PubMed

    McMullen, Richard J; Gilger, Brian C

    2006-01-01

    To determine ocular dimensions (A- and B-scan ultrasound) and corneal curvature (radius of corneal diameter determined in B-scan ultrasound) in the equine eye and to calculate the appropriate dioptric power for a posterior chamber intraocular lens (IOL) necessary to achieve emmetropia in the eyes of horses undergoing lens extraction. Fourteen clinically normal adult horses of various breeds. Additionally, for comparison, one American Miniature colt foal, and one 2.5-year-old Shire gelding were examined. B-scan ultrasound was performed on one eye from each horse. One eye from both the Shire and the American Miniature were examined for comparison. Data from ultrasound (globe measurements and corneal curvature), and the estimated postoperative IOL positions were entered into theoretical IOL formulas (Binkhorst and Retzlaff theoretical formulas) in order to calculate the predicted IOL strength required to achieve emmetropia after lens extraction in horses. Mean axial length of globes was 39.23 mm +/- 1.26 mm, mean preoperative anterior chamber depth (ACD) was 5.63 +/- 0.86 mm, and mean lens thickness was 11.75 +/- 0.80 mm. Predicted postoperative ACD (PACD) was calculated as the ACD plus 50% of the lens thickness. Additionally, PACD 2 mm anterior and 2 mm posterior to the center of the lens were calculated in order to evaluate the effect of IOL position on its required refractive power. Required IOL strength calculated, using the three values for the predicted postoperative ACD, was 29.91 D +/- 2.50, 29 D +/- 2.52 (center of lens); 27.13 D +/- 2.27, 26.33 D +/- 2.20 (2 mm anterior to center of lens); and 33.18 D +/- 2.78, 32.24 D +/- 2.68 (2 mm posterior to center of lens) with the Binkhorst and Retzlaff theoretical formulas, respectively. An IOL of substantially lower diopter strength than that needed in either dogs or cats is required to achieve emmetropia after lens extraction in adult horses. IOL strength of approximately 30 D, depending on where the IOL ultimately comes to rest, will probably be required.

  2. Quality control of ultrasound for fetal biometry: results from the INTERGROWTH-21(st) Project.

    PubMed

    Cavallaro, Angelo; Ash, Stephen T; Napolitano, Raffaele; Wanyonyi, Sikolia; Ohuma, Eric O; Molloholli, Malid; Sande, Joyce; Sarris, Ippokratis; Ioannou, Christos; Norris, Tess; Donadono, Vera; Carvalho, Maria; Purwar, Manorama; Barros, Fernando C; Jaffer, Yasmin A; Bertino, Enrico; Pang, Ruyan; Gravett, Michael G; Salomon, Laurent J; Noble, Julia Alison; Altman, Douglas G; Papageorghiou, Aris T

    2017-07-18

    To assess a comprehensive package of ultrasound quality control in a large multicentre study of fetal growth - the Fetal Growth Longitudinal Study of the INTERGROWTH-21(st) Project. We performed quality control (QC) measures on 20,313 ultrasound scan images taken prospectively from 4,321 fetuses at 14-41 weeks' gestation in eight geographical locations. At the time of each ultrasound examination, three fetal biometric variables were measured in triplicate on separately generated images: head circumference (HC), abdominal circumference (AC) and femur length (FL). All measurements were taken in a blinded fashion. QC had two elements: 1) qualitative QC: visual assessment by sonographers at each study site of their images based on specific criteria with 10% of images being re-assessed at the Oxford-based Ultrasound Quality Unit (compared using an adjusted kappa statistic), and 2) quantitative QC: measurement data were assessed by (a) comparing the first, second and third measurement (intraobserver variability); (b) re-measurement of caliper replacement in 10% (interobserver variability), both by Bland-Altman plots, and (c) plotting frequency histograms of the SDs of triplicate measurements and assessing how many were above or below 2SDs of the expected distribution. The system allowed the sonographers' performance to be regularly monitored. A high level of agreement between the self- and external scoring was demonstrated for all measurements (kappa = 0.99 [95% confidence interval: 0.98, 0.99] for HC, 0.98 [0.97, 0.99] for AC, and 0.96 [0.95, 0.98] for FL. Intraobserver variability (95% limits of agreement (LoA)) of ultrasound measures for HC, AC and FL were ±3%, ±6% and ±6%, respectively; the corresponding values for interobserver variability were ±4%, ±6% and ±6%. The SD distribution of triplicate measurements for all biometric variables showed excessive variability for three of 31 sonographers, allowing prompt identification and retraining. Qualitative and quantitative QC monitoring was feasible and highly reproducible in a large multicentre research study, which facilitated the production of high-quality ultrasound images. We recommend that the QC system we developed is implemented in future research studies and clinical practice. This article is protected by copyright. All rights reserved.

  3. PALEOBIOLOGICAL APPLICATIONS OF THREE-DIMENSIONAL BIOMETRY ON LARGER BENTHIC FORAMINIFERA: A NEW ROUTE OF DISCOVERIES.

    PubMed

    Briguglio, Antonino; Hohenegger, Johann; Less, György

    2013-01-01

    Four specimens of larger benthic foraminifera (the Recent Palaeonummulites venosus and Operculina ammonoides, and the phylogenetically related Paleogene Nummulites fabianii and N. fichteli) were investigated by X-ray tomography. The resulting three-dimensional measurements enabled a comprehensive, quantitative study of shell morphology to interpret cell growth without specific shell preparation and/or destruction. After segmentation and extraction of all scanned lumina, the following characters were measured on all chambers of each specimen: chamber volume, septal distance, chamber height, and chamber width. The sequence of chamber lumina follows either a logistic function (Palaeonummulites, Operculina), where the deceleration in growth rate of the latest chambers could mark the onset of reproduction, or it can be modeled by a series of stepwise functions with differing constants (Nummulites). Variations around the growth model are either periodic, following external cycles, or random as expressed by abrupt deviations. Therefore, they may reflect the response of the cell to environmental changes in terms of cyclic changes (e.g., seasonality) or single events (e.g., predator attack). Correlations between chamber volume and the other chamber parameters show that septal distance always matches the sequence in chamber volume and can therefore be used as a proxy for environmental analyses in both growth models. Chamber height and width often remain constant around their function and rarely deviate drastically to accommodate the needed lumen for retaining test size and shape. Chamber width may vary according to chamber volume in involute specimens, whereas both chamber height and width correlate with volume in those tests following an Archimedean spiral. X-ray-tomography shows particular promise in determining which parameters that can be assessed routinely in two dimensions primarily reflect environmental conditions vs. parameters best used for taxonomic identification and for systematic lineage reconstruction.

  4. Anterior segment biometry using ultrasound biomicroscopy and the Artemis-2 very high frequency ultrasound scanner.

    PubMed

    Al-Farhan, Haya M; Almutairi, Reem N

    2013-01-01

    To compare the precision of anterior chamber angle (ACA) and anterior chamber depth (ACD) measurements taken with ultrasound biomicroscopy (UBM) and the Artemis-2 Very High Frequency Ultrasound Scanner (VHFUS) in normal subjects. Prospective study. We randomly selected one eye from each of 59 normal subjects in this study. Two subjects dropped out of the study; the associated data were excluded from analysis. ACA and ACD measurements were obtained using the VHFUS and the UBM. The results were compared statistically using repeated-measures analysis of variance for the intraobserver repeatability, unpaired t-test, and limits of agreement. The average ACA values for the UBM and the VHFUS (±standard deviation) were 41.83° ± 5.03° and 33.36° ± 6.03°, respectively. The average ACD values were 2.96 ± 0.34 mm and 2.87 ± 0.31 mm. The intraobserver repeatability analysis of variance P-values for ACA and ACD measurements using UBM were 0.10 and 0.68, respectively; for the Artemis-2 VHFUS, the respective values were 0.68 and 0.09. The difference in ACA measurements was statistically significant (t = 8.41; P < 0.0001), while the difference in ACD values was not (t = 1.51; P < 0.13). The mean ACA difference was 8.50° ± 2.50°, and the limits of agreement were +13.30° to -3.60°. The mean ACD difference was 0.09 ± 0.27 mm, and the limits of agreement ranged from 0.61 mm to -0.43 mm. The mean difference percentage of ACD was 3.1% for both instruments. In case of the ACD, both instruments can be used interchangeably; however, with the ACA instruments, they cannot be used interchangeably.

  5. Characteristics of Ethical Business Cultures

    ERIC Educational Resources Information Center

    Ardichvili, Alexandre A.; Jondle, Douglas J.; Mitchell, James A.

    2008-01-01

    The purpose of this study was to identify general characteristics attributed to ethical business cultures by executives from a variety of industries. Our research identified five clusters of characteristics: (1) Mission- and Values-Driven; (2) Stakeholder Balance; (3) Leadership Effectiveness; (4) Process Integrity; and (5) Long-term Perspective.…

  6. Trend of airplane flight characteristics

    NASA Technical Reports Server (NTRS)

    Von Koppen, Joachim

    1933-01-01

    This report describes the development of airplane characteristics since the war and indicates the direction development should take in the immediate future. Some of the major topics include: the behavior of an airplane about its lateral, vertical, and longitudinal axes. Behavior at large angles of attack and landing characteristics are also included.

  7. Voltage/temperature charge characteristics

    NASA Technical Reports Server (NTRS)

    Betz, F. E.

    1978-01-01

    A series of nickel cadmium batteries were tested to determine the effects of boltages and various temperatures on the charge discharge ratios and the recharge percentage. It was concluded that the selection of a proper temperature should consider the satellite orbit characteristics, the cell operating characteristics, the battery operating temperature range, and the final taper charge current.

  8. Naupliar and Metanaupliar Development of Thysanoessa raschii (Malacostraca, Euphausiacea) from Godthåbsfjord, Greenland, with a Reinstatement of the Ancestral Status of the Free-Living Nauplius in Malacostracan Evolution

    PubMed Central

    Akther, Hasna; Agersted, Mette Dalgaard; Olesen, Jørgen

    2015-01-01

    The presence of a characteristic crustacean larval type, the nauplius, in many crustacean taxa has often been considered one of the few uniting characters of the Crustacea. Within Malacostraca, the largest crustacean group, nauplii are only present in two taxa, Euphauciacea (krill) and Decapoda Dendrobranchiata. The presence of nauplii in these two taxa has traditionally been considered a retained primitive characteristic, but free-living nauplii have also been suggested to have reappeared a couple of times from direct developing ancestors during malacostracan evolution. Based on a re-study of Thysanoessa raschii (Euphausiacea) using preserved material collected in Greenland, we readdress this important controversy in crustacean evolution, and, in the process, redescribe the naupliar and metanaupliar development of T. raschii. In contrast to most previous studies of euphausiid development, we recognize three (not two) naupliar (= ortho-naupliar) stages (N1-N3) followed by a metanauplius (MN). While there are many morphological changes between nauplius 1 and 2 (e.g., appearance of long caudal setae), the changes between nauplius 2 and 3 are few but distinct. They involve the size of some caudal spines (largest in N3) and the setation of the antennal endopod (an extra seta in N3). A wider comparison between free-living nauplii of both Malacostraca and non-Malacostraca revealed similarities between nauplii in many taxa both at the general level (e.g., the gradual development and number of appendages) and at the more detailed level (e.g., unclear segmentation of naupliar appendages, caudal setation, presence of frontal filaments). We recognize these similarities as homologies and therefore suggest that free-living nauplii were part of the ancestral malacostracan type of development. The derived morphology (e.g., lack of feeding structures, no fully formed gut, high content of yolk) of both euphausiid and dendrobranchiate nauplii is evidently related to their non

  9. Naupliar and Metanaupliar Development of Thysanoessa raschii (Malacostraca, Euphausiacea) from Godthåbsfjord, Greenland, with a Reinstatement of the Ancestral Status of the Free-Living Nauplius in Malacostracan Evolution.

    PubMed

    Akther, Hasna; Agersted, Mette Dalgaard; Olesen, Jørgen

    2015-01-01

    The presence of a characteristic crustacean larval type, the nauplius, in many crustacean taxa has often been considered one of the few uniting characters of the Crustacea. Within Malacostraca, the largest crustacean group, nauplii are only present in two taxa, Euphauciacea (krill) and Decapoda Dendrobranchiata. The presence of nauplii in these two taxa has traditionally been considered a retained primitive characteristic, but free-living nauplii have also been suggested to have reappeared a couple of times from direct developing ancestors during malacostracan evolution. Based on a re-study of Thysanoessa raschii (Euphausiacea) using preserved material collected in Greenland, we readdress this important controversy in crustacean evolution, and, in the process, redescribe the naupliar and metanaupliar development of T. raschii. In contrast to most previous studies of euphausiid development, we recognize three (not two) naupliar (= ortho-naupliar) stages (N1-N3) followed by a metanauplius (MN). While there are many morphological changes between nauplius 1 and 2 (e.g., appearance of long caudal setae), the changes between nauplius 2 and 3 are few but distinct. They involve the size of some caudal spines (largest in N3) and the setation of the antennal endopod (an extra seta in N3). A wider comparison between free-living nauplii of both Malacostraca and non-Malacostraca revealed similarities between nauplii in many taxa both at the general level (e.g., the gradual development and number of appendages) and at the more detailed level (e.g., unclear segmentation of naupliar appendages, caudal setation, presence of frontal filaments). We recognize these similarities as homologies and therefore suggest that free-living nauplii were part of the ancestral malacostracan type of development. The derived morphology (e.g., lack of feeding structures, no fully formed gut, high content of yolk) of both euphausiid and dendrobranchiate nauplii is evidently related to their non

  10. Characteristics of Home Economics Researchers.

    ERIC Educational Resources Information Center

    Gorman, Anne M.; Scruggs, M. Marguerite

    1984-01-01

    This study describes researchers in home economics and characteristics associated with their research productivity. The researchers are characterized as having doctoral degrees, being in home economics education, being employed in colleges or universities, and being professionally experienced. (JOW)

  11. [Collage work characteristics and personality].

    PubMed

    Sato, Shizuka

    2002-06-01

    The purpose of this study was to investigate the relationship between personality and characteristics in collage work. Seventy undergraduates filled the Yatabe-Guilford (YG) personality test and produced a piece of collage work. The YG personality types were not different in terms of collage work characteristics. However, emotional adaptation and introvert/extrovert scores were reflected in the number of cuttings used in the piece. General activity score was reflected in the number of vehicle pictures used. Those who used an eye picture had a tendency to be depressed and lacking in confidence. Those who used a "stone circle" picture tended to be more emotionally adapted and extroverted. The results suggested a possibility that personality traits were reflected in specific characteristics in collage work.

  12. Transcoding characteristics of Web images

    NASA Astrophysics Data System (ADS)

    Chandra, Surendar; Gehani, Ashish; Schlatter Ellis, Carla; Vahdat, Amin

    2000-12-01

    Transcoding is a technique employed by network proxies to dynamically customize multimedia objects for prevailing network conditions and individual client characteristics. Transcoding can be performed along a number of different axes and the specific transcoding technique used depends on the type of multimedia object. Our goal in this paper is to understand the nature of typical Internet images and their transcoding characteristics. We focus our attention on transcodings intended to customize an image for file size savings. Our results allow the developers of a transcoding proxy server to choose the appropriate transcoding techniques for the important classes of Internet images. We analyze the characteristics of images available on the Web through a representative trace. We show that most GIF images accessed on the Internet are small; about 80% of the GIF images are smaller than 6 KBs. JPEG images are larger than GIF images; about 40% of the JPEG images are larger than 6 KBs. We also establish the characteristics of popular image transcoding operations. We show that for JPEG images, the JPEG compression metric and a transcoding that reduces the spatial geometry are productive transcoding operations (saves at least 50% of the file size for 50% of the images). Our systematic study of image characteristics leads to some surprising results. For example, a naive spatial geometry reduction of GIF images by a factor of 2 along each axis actually causes an increase in the file size compared to the original image for 40% of the images. Thus it is important to understand the characteristics of individual images before choosing the proper transcoding operation.

  13. Uncertainty relations for characteristic functions

    NASA Astrophysics Data System (ADS)

    Rudnicki, Łukasz; Tasca, D. S.; Walborn, S. P.

    2016-02-01

    We present the uncertainty relation for the characteristic functions (ChUR) of the quantum mechanical position and momentum probability distributions. This inequality is more general than the Heisenberg uncertainty relation and is saturated in two extreme cases for wave functions described by periodic Dirac combs. We further discuss a broad spectrum of applications of the ChUR; in particular, we constrain quantum optical measurements involving general detection apertures and provide the uncertainty relation that is relevant for loop quantum cosmology. A method to measure the characteristic function directly using an auxiliary qubit is also briefly discussed.

  14. NLS nozzle base flow characteristics

    NASA Technical Reports Server (NTRS)

    Erhart, John J.

    1992-01-01

    The flow characteristics of the National Launch System (NLS) nozzle base area need to be determined in order for heat transfer rates to be estimated. The objective of this work is to calculate these flow characteristics using computational fluid dynamics (CFD). A full Navier-Stokes code in an axisymmetric mode, using a kappa-epsilon model with wall functions is applied. Calculations were completed at an altitude of 3,250 and 80,000 feet in the flight trajectory. The results show flow features which can affect vehicle design. Calibration of a 3-D case with data is underway. Information is given in viewgraph form.

  15. Compressibility Characteristics of Compacted Snow

    DTIC Science & Technology

    1976-06-01

    Cornpressibility characteristics 7Jj i C’p of compacted snowifAG2� 004 t Cover: ~ ~ ~ ~ ~ ~ ~ ~ a - Thn***o htgrp fpoyrsaliekAmgife i ote rm...nwcmrse to7 asa 10 Phtgahb nhn Gow1 CRREL Report 76-21 Compressibility characteristics of compacted snow %i" Gunars Abele and Anthony J. Cow I ~ June 1976 A ...c , I fu. A AD,:j ly M3rs CORPS OF ENGINEERS, U.S. ARMY COLD REGIONS RESEARCH AND ENGINEERZ]NG LABORATORY HANOVER, NEW HAMPSHIRE Approved for public

  16. Handbook of sensor technical characteristics

    NASA Astrophysics Data System (ADS)

    Tanner, S.

    1982-07-01

    Space and terrestrial applications remote sensor systems are described. Each sensor is presented separately. Information is included on its objectives, description, technical characteristics, data products obtained, data archives location, period of operation, and measurement and potential derived parameters. Each sensor is cross indexed.

  17. Personality Characteristics and Student Housing.

    ERIC Educational Resources Information Center

    Yonge, George; Regan, Mary

    This study aimed to determine relationships between a student's personality characteristics and his choice of a living residence while a senior at the University of California, Davis. A phenomological approach--or, the idea that a person's actions and decisions reveal something about his personality--was used. Data for the study were derived from…

  18. Characteristics of Successful Native Leaders.

    ERIC Educational Resources Information Center

    Silverman, Robert J.; Demmert, William G., Jr.

    Characteristics were profiled for 40 southeast Alaskan Haida, Tlingit, and Tsimshian tribal members in positions of responsibility in business, government, or a profession. Respondents had found school easy, did well, liked school, and participated in school-related activities. Positive influence and encouragement of family members, especially…

  19. Characteristics of Effective Leadership Networks

    ERIC Educational Resources Information Center

    Leithwood, Kenneth; Azah, Vera Ndifor

    2016-01-01

    Purpose: The purpose of this paper is to inquire about the characteristics of effective school leadership networks and the contribution of such networks to the development of individual leaders' professional capacities. Design/methodology/approach: The study used path-analytic techniques with survey data provided by 450 school and district leaders…

  20. Artistic Understanding and Motivational Characteristics

    ERIC Educational Resources Information Center

    Lekue, Pablo

    2015-01-01

    This study aims to analyse artistic understanding in primary and secondary education and the relationship between this understanding and motivational characteristics such as goal orientation, engagement in art activities and attitude to art education at school, which determine (according to prior research) learners' academic achievement, in…

  1. Characteristics of Effective Leadership Networks

    ERIC Educational Resources Information Center

    Leithwood, Kenneth; Azah, Vera Ndifor

    2016-01-01

    Purpose: The purpose of this paper is to inquire about the characteristics of effective school leadership networks and the contribution of such networks to the development of individual leaders' professional capacities. Design/methodology/approach: The study used path-analytic techniques with survey data provided by 450 school and district leaders…

  2. School Choice with Chinese Characteristics

    ERIC Educational Resources Information Center

    Wu, Xiaoxin

    2012-01-01

    This paper explores the major characteristics of school choice in the Chinese context. It highlights the involvement of cultural and economic capital, such as choice fees, donations, prize-winning certificates and awards in gaining school admission, as well as the use of social capital in the form of "guanxi". The requirement for these…

  3. Characteristics of Autism. Literature Review.

    ERIC Educational Resources Information Center

    Miller, Marilyn

    The literature review considers characteristics of autism in three general areas of impairment: communication; cognition; and social behavior. Briefly noted are incidence and etiology facts. A variety of definitions are presented including a psychiatric definition, Leo Kanner's definition, and the definition of the Autism Study Committee of Iowa.…

  4. Handbook of sensor technical characteristics

    NASA Technical Reports Server (NTRS)

    Tanner, S.

    1982-01-01

    Space and terrestrial applications remote sensor systems are described. Each sensor is presented separately. Information is included on its objectives, description, technical characteristics, data products obtained, data archives location, period of operation, and measurement and potential derived parameters. Each sensor is cross indexed.

  5. School Choice with Chinese Characteristics

    ERIC Educational Resources Information Center

    Wu, Xiaoxin

    2012-01-01

    This paper explores the major characteristics of school choice in the Chinese context. It highlights the involvement of cultural and economic capital, such as choice fees, donations, prize-winning certificates and awards in gaining school admission, as well as the use of social capital in the form of "guanxi". The requirement for these…

  6. Attitudes and Characteristics of Nonusers.

    ERIC Educational Resources Information Center

    Stein, Ann; Kahn, Malcolm

    The attitudes and life-style characteristics of 58 undergraduate nonusers of illegal drugs were evaluated through comparisons with 47 regular marijuana users. The nonusers were found to be more settled in their values, more goal-directed, and more involved academically. They also had higher Grade Point Averages. The nonusers appeared to be both…

  7. Acoustic Absorption Characteristics of People.

    ERIC Educational Resources Information Center

    Kingsbury, H. F.; Wallace, W. J.

    1968-01-01

    The acoustic absorption characteristics of informally dressed college students in typical classroom seating are shown to differ substantially from data for formally dressed audiences in upholstered seating. Absorption data, expressed as sabins per person or absorption coefficient per square foot, shows that there is considerable variation between…

  8. Family Linked Characteristics of Poverty.

    ERIC Educational Resources Information Center

    Osmond, Marie Withers; Grigg, Charles M.

    Questions raised by previous research on poverty, addressing the comparative trends in black and white family stability, and the cumulative nature of poverty linked characteristics are studied here. In addressing critical issues resulting from previous research, this study further elucidates the concepts of marital and family stability, uses the…

  9. Receiver Operating Characteristic (ROC) Analysis

    ERIC Educational Resources Information Center

    Krupinski, Elizabeth A.

    2017-01-01

    Visual expertise covers a broad range of types of studies and methodologies. Many studies incorporate some measure(s) of observer performance or how well participants perform on a given task. Receiver Operating Characteristic (ROC) analysis is a method commonly used in signal detection tasks (i.e., those in which the observer must decide whether…

  10. Perceived Characteristics of an Innovation.

    ERIC Educational Resources Information Center

    Holloway, Robert E.

    This study investigated the characteristics of an innovative cooperative high school-college program as perceived by principals of adopting and nonadopting schools. The data from survey questionnaires with 24 Likert-type items were reduced to six factors: observability, status, simplicity, cost, trialability, and relative…

  11. Characteristic impedance of microstrip lines

    NASA Technical Reports Server (NTRS)

    Bailey, M. C.; Deshpande, M. D.

    1989-01-01

    The dyadic Green's function for a current embedded in a grounded dielectric slab is used to analyze microstrip lines at millimeter wave frequencies. The dyadic Green's function accounts accurately for fringing fields and dielectric cover over the microstrip line. Using Rumsey's reaction concept, an expression for the characteristic impedance is obtained. The numerical results are compared with other reported results.

  12. Characteristics of Independent Music Teachers

    ERIC Educational Resources Information Center

    Upitis, Rena; Abrami, Philip C.; Brook, Julia; Boese, Karen; King, Matthew

    2017-01-01

    The purpose of the present study was to learn about the characteristics of independent music teachers, their beliefs about music teaching, and their studio practices. A self-report survey included questions about the teachers' (a) background experiences, (b) pedagogical approaches, (c) use of digital technologies, and (d) professional development…

  13. Characteristics of Effective Networking Environments.

    ERIC Educational Resources Information Center

    Kaye, Judith C.

    This document chronicles a project called Model Nets, which studies the characteristics of computer networks that have a positive impact on K-12 learning. Los Alamos National Laboratory undertook the study so that their recommendations could help federal agencies wisely fund networking projects in an era when the national imperative has driven…

  14. Computerized Investigations of Battery Characteristics.

    ERIC Educational Resources Information Center

    Hinrichsen, P. F.

    2001-01-01

    Uses a computer interface to measure terminal voltage versus current characteristic of a variety of batteries, their series and parallel combinations, and the variation with discharge. The concept of an internal resistance demonstrates that current flows through the battery determine the efficiency and serve to introduce Thevenin's theorem.…

  15. Demand Characteristics, Moods, and Helping

    ERIC Educational Resources Information Center

    Wispe, Lauren; And Others

    1977-01-01

    Procedures used in empathy-helping studies suggest results may be due to demand characteristics. Two studies were run to investigate especially the mood induction process. One reproduced the Aderman-Berkowitz main mood effects. Another showed that after seeing a help-non-help incident, mood effects were demonstrated only when Ss knew the research…

  16. Acoustic Absorption Characteristics of People.

    ERIC Educational Resources Information Center

    Kingsbury, H. F.; Wallace, W. J.

    1968-01-01

    The acoustic absorption characteristics of informally dressed college students in typical classroom seating are shown to differ substantially from data for formally dressed audiences in upholstered seating. Absorption data, expressed as sabins per person or absorption coefficient per square foot, shows that there is considerable variation between…

  17. Characteristics of Male Alcohol Offenders.

    ERIC Educational Resources Information Center

    Ratliff, Katharine G.; Ellis, Thomas E.

    Because most studies investigating psychological profiles of subjects convicted of driving under the influence of alcohol (DUI) have been conducted at the time of arrest or treatment, it is unclear whether subjects' anxiety, depression, and hostility represent "trait" characteristics central to alcohol abuse or "state"…

  18. Characteristics of the Federal Executive.

    ERIC Educational Resources Information Center

    Civil Service Commission, Washington, DC.

    The personal characteristics, educational background, occupations, and attitudes of 54 Federal Executives who attended Session IX of the Federal Executive Institute, U. S. Civil Service Commission, are given. The average age of the group was 47.6 years (range 36 to 61). The federal grades were 18% in GS-5, 66% in GS-16 and equivalent, and 16% in…

  19. Characteristics of Successful Developmental Educators.

    ERIC Educational Resources Information Center

    Gabriel, Dennis

    1987-01-01

    The body of folk wisdom and research on the characteristics of successful developmental educators indicates, among other findings, that: (1) the single most important factor influencing learning is not the teacher but what the learner already knows; (2) excellence in teaching involves a genuine concern for students; (3) successful instructors are…

  20. The prediction of airfoil characteristics

    NASA Technical Reports Server (NTRS)

    Higgins, George J

    1930-01-01

    This report describes and develops methods by which the aerodynamic characteristics of an airfoil may be calculated with sufficient accuracy for use in airplane design. These methods for prediction are based on the present aerodynamic theory and on empirical formulas derived from data obtained in the N. A. C. A. variable density wind tunnel at a Reynolds number corresponding approximately to full scale. (author)

  1. Artistic Understanding and Motivational Characteristics

    ERIC Educational Resources Information Center

    Lekue, Pablo

    2015-01-01

    This study aims to analyse artistic understanding in primary and secondary education and the relationship between this understanding and motivational characteristics such as goal orientation, engagement in art activities and attitude to art education at school, which determine (according to prior research) learners' academic achievement, in…

  2. Computerized Investigations of Battery Characteristics.

    ERIC Educational Resources Information Center

    Hinrichsen, P. F.

    2001-01-01

    Uses a computer interface to measure terminal voltage versus current characteristic of a variety of batteries, their series and parallel combinations, and the variation with discharge. The concept of an internal resistance demonstrates that current flows through the battery determine the efficiency and serve to introduce Thevenin's theorem.…

  3. Tourette's Syndrome: Characteristics and Interventions.

    ERIC Educational Resources Information Center

    Prestia, Kelly

    2003-01-01

    This article overviews the characteristics of children and youth with Tourette syndrome and provides suggestions that can be used in the school setting for addressing academic concerns, social-emotional concerns, and physical concerns. Teachers are urged to break down assignments, allow computer use to complete work, and give preferential seating.…

  4. Tourette's Syndrome: Characteristics and Interventions.

    ERIC Educational Resources Information Center

    Prestia, Kelly

    2003-01-01

    This article overviews the characteristics of children and youth with Tourette syndrome and provides suggestions that can be used in the school setting for addressing academic concerns, social-emotional concerns, and physical concerns. Teachers are urged to break down assignments, allow computer use to complete work, and give preferential seating.…

  5. Fracture characteristics of balloon films

    NASA Technical Reports Server (NTRS)

    Portanova, Marc A.

    1989-01-01

    An attempt was made to determine the failure modes of high altitude scientific balloons through an investigation of the fracture characteristics of the thin polyethylene films. Two films were the subject of the evaluation, Winzen Int.'s Stratafilm SF-85 and Raven Industries' Astro-E. Research began with an investigation of the film's cold brittleness point and it's effect on the ultimate strength and elasticity of the polyethylene film. A series of preliminary investigations were conducted to develop an understanding of the material characteristics. The primary focus of this investigation was on the notch sensitivity of the films. Simple stress strain tests were also conducted to enable analysis employing fracture toughness parameters. Studies were conducted on both film types at 23 C (room temperature), -60 C, -90 C, and -120 C.

  6. Map characteristics of Landsat mosaics

    NASA Technical Reports Server (NTRS)

    Zobrist, A. L.; Bryant, N. A.

    1979-01-01

    Map characteristics of the Landsat mosaics developed at JPL are considered. Procedures for digital mosaicking of Landsat frames to standard map projections were used to mosaic at full resolution ten scenes over the California desert region and twenty-one scenes over Arizona. The procedures are analyzed for horizontal positioning error (global and local) and the potential for classification error associated with the adjustment of brightness of Z values between frames; the use of this technology for the mapping of extensive features is discussed. Mosaicking facilities, techniques, mapping accuracy, and thematic mapping characteristics are described. A comparative analysis of Landsat mosaicking technology developed at Goddard Space Flight Center, IBM Gaithersburg, and USGS Flagstaff is made, and suggestions are given for algorithm development to improve systems capacity and ability to handle a variety of cases.

  7. The Characteristic Curves of Water

    NASA Astrophysics Data System (ADS)

    Neumaier, Arnold; Deiters, Ulrich K.

    2016-09-01

    In 1960, E. H. Brown defined a set of characteristic curves (also known as ideal curves) of pure fluids, along which some thermodynamic properties match those of an ideal gas. These curves are used for testing the extrapolation behaviour of equations of state. This work is revisited, and an elegant representation of the first-order characteristic curves as level curves of a master function is proposed. It is shown that Brown's postulate—that these curves are unique and dome-shaped in a double-logarithmic p, T representation—may fail for fluids exhibiting a density anomaly. A careful study of the Amagat curve (Joule inversion curve) generated from the IAPWS-95 reference equation of state for water reveals the existence of an additional branch.

  8. Hydrodynamic characteristics of artificial lungs.

    PubMed

    Dierickx, P W; De Somer, F; De Wachter, D S; Van Nooten, G; Verdonck, P R

    2000-01-01

    An artificial lung is used during cardiopulmonary bypass to oxygenate blood and to control blood temperature. The pressure drop-flow rate characteristics of the membrane compartment in three hollow fiber membrane oxygenators were determined in vitro to characterize design features. Results are presented in a unique dimensionless relationship between Euler number, N(Eu) (ratio of pressure drop to kinetic energy), and Reynolds number, N(Re) (ratio of inertial to viscous forces), and are a function of the device porosity, epsilon, and a characteristic device length, xi, defined as the ratio of the mean blood path and manifold length: [equation in text]. This dimensionless approach allows us (1) to compare oxygenators independently, and (2) to relate water tests to blood.

  9. Map characteristics of Landsat mosaics

    NASA Technical Reports Server (NTRS)

    Zobrist, A. L.; Bryant, N. A.

    1979-01-01

    Map characteristics of the Landsat mosaics developed at JPL are considered. Procedures for digital mosaicking of Landsat frames to standard map projections were used to mosaic at full resolution ten scenes over the California desert region and twenty-one scenes over Arizona. The procedures are analyzed for horizontal positioning error (global and local) and the potential for classification error associated with the adjustment of brightness of Z values between frames; the use of this technology for the mapping of extensive features is discussed. Mosaicking facilities, techniques, mapping accuracy, and thematic mapping characteristics are described. A comparative analysis of Landsat mosaicking technology developed at Goddard Space Flight Center, IBM Gaithersburg, and USGS Flagstaff is made, and suggestions are given for algorithm development to improve systems capacity and ability to handle a variety of cases.

  10. Roughness characteristics of natural channels

    USGS Publications Warehouse

    Barnes, Harry Hawthorne

    1967-01-01

    Color photographs and descriptive data are presented for 50 stream channels for which roughness coefficients have been determined. All hydraulic computations involving flow in open channels require an evaluation of the roughness characteristics of the channel. In the absence of a satisfactory quantitative procedure this evaluation remains chiefly an art. The ability to evaluate roughness coefficients must be developed through experience. One means of gaining this experience is by examining and becoming acquainted with the appearance of some typical channels whose roughness coefficients are known. The photographs and data contained in this report represent a wide range of channel conditions. Familiarity with the appearance, geometry, and roughness characteristics of these channels will improve the engineer's ability to select roughness coefficients for other channels .

  11. Radio characteristics of galactic nuclei

    NASA Astrophysics Data System (ADS)

    Condon, J. J.

    1986-02-01

    Radio characteristics of galactic nuclei, providing such unique information as spectral data on source variability, and the long-term history of the central engine and its duration of activity and total energy, are reviewed. The compact radio source characteristics are complicated by orientation-dependent relativistic beaming and by refractive focusing in the interstellar medium. Incoherent synchrotron radiation is thought to be the emission mechanism, with the result that synchrotron self-absorption in compact sources hides the central engine from direct radio observation. However, the history revealed by the extended jets and lobes of radio galaxies and quasars favors a single massive object not supported by radiation pressure, either a spinar or a black hole, as the energy source in radio-galaxy nuclei.

  12. Calculation of gas turbine characteristic

    NASA Astrophysics Data System (ADS)

    Mamaev, B. I.; Murashko, V. L.

    2016-04-01

    The reasons and regularities of vapor flow and turbine parameter variation depending on the total pressure drop rate π* and rotor rotation frequency n are studied, as exemplified by a two-stage compressor turbine of a power-generating gas turbine installation. The turbine characteristic is calculated in a wide range of mode parameters using the method in which analytical dependences provide high accuracy for the calculated flow output angle and different types of gas dynamic losses are determined with account of the influence of blade row geometry, blade surface roughness, angles, compressibility, Reynolds number, and flow turbulence. The method provides satisfactory agreement of results of calculation and turbine testing. In the design mode, the operation conditions for the blade rows are favorable, the flow output velocities are close to the optimal ones, the angles of incidence are small, and the flow "choking" modes (with respect to consumption) in the rows are absent. High performance and a nearly axial flow behind the turbine are obtained. Reduction of the rotor rotation frequency and variation of the pressure drop change the flow parameters, the parameters of the stages and the turbine, as well as the form of the characteristic. In particular, for decreased n, nonmonotonic variation of the second stage reactivity with increasing π* is observed. It is demonstrated that the turbine characteristic is mainly determined by the influence of the angles of incidence and the velocity at the output of the rows on the losses and the flow output angle. The account of the growing flow output angle due to the positive angle of incidence for decreased rotation frequencies results in a considerable change of the characteristic: poorer performance, redistribution of the pressure drop at the stages, and change of reactivities, growth of the turbine capacity, and change of the angle and flow velocity behind the turbine.

  13. MRI characteristics of tuberculous spondylitis.

    PubMed

    Currie, S; Galea-Soler, S; Barron, D; Chandramohan, M; Groves, C

    2011-08-01

    Spondylitis is the most common osseous manifestation of Mycobacterium tuberculosis infection. Although treatable, it continues to cause significant mortality and morbidity. Early diagnosis through familiarity with its imaging characteristics is essential to permit rapid treatment and prevent potential life-limiting consequences. In this review, we demonstrate the key magnetic resonance imaging features of this disease. Copyright © 2011 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  14. Endfire tapered slot antenna characteristics

    NASA Technical Reports Server (NTRS)

    Schaubert, D. H.

    1989-01-01

    Typical configurations and operating characteristics for endfire tapered slot antennas are described. The feed transition modeling and moment method modeling techniques are utilized to predict antenna performance. The radiation pattern and cross polarization properties for the linearly tapered slot antennas are examined. Endfire tapered slot antennas are applicable for wide-band scanning arrays and focal plane arrays for imaging and multiple beam reflector systems.

  15. Entrepreneurship Psychological Characteristics of Nurses.

    PubMed

    Dehghanzadeh, Mohammad Reza; Kholasehzadeh, Golrasteh; Birjandi, Masoumeh; Antikchi, Ensieh; Sobhan, Mohamad Reza; Neamatzadeh, Hossein

    2016-09-01

    Nurses are full partners with other health care professionals. Until fairly recently the scope of nurses potential in entrepreneurship has not been widely recognized. The present study tries to evaluate entrepreneurship psychological characteristics among nurses. The survey instrument included scales measuring entrepreneurship psychological characteristics including locus of control, need for achievement, risk taking propensity, ambiguity tolerance, and innovation, among nurses in the Shahid Sadoughi Hospital, Yazd, Iran in 2013. In this study average of entrepreneurship psychological characteristics of nurses which are higher than standard mark. The majority of the nurses have average entrepreneurship (20.4%). It means that they have some strong entrepreneurship. The result show that average of the need for achievement is 34.5%, the locus of control 33.8%, risk taking propensity 33.2%, ambiguity tolerance 34.2%, and innovation 41.6%. The results indicate that the 4 dimensions of the need for achievement, risk taking, Ambiguity Tolerance, and Innovation were significant. However, the locus of control is not significant at a 0.05 significance level. In terms, entrepreneurially nurses are comparatively more innovative, have risk taking attitudes, need for achievement, Ambiguity Tolerance, and Innovation. Results largely support significant positive relationships between psychological traits and entrepreneurial orientations.

  16. Characteristics of good anaesthesia teachers.

    PubMed

    Cleave-Hogg, D; Benedict, C

    1997-06-01

    The Department of Anaesthesia undertook a qualitative study to a) reveal the characteristics of teachers who had been identified as "good," and b) explore the levels of epistemological development (defined as conceptualization of knowledge) that are evidenced. Changes in medical education curricula have focused attention on the ways in which medical teaching staff conceptualize the learning/teaching interactions and their ability to alter or modify their teaching styles. Teachers are often assessed or informally recognized as "good teachers," but there are few indicators to guide what is meant by the label in anaesthesia. Teachers who had consistently received overall ratings of 4+ on a 5 point rating scale over a five year period were selected to be interviewed. Data were analyzed a) noting key teaching characteristics and patterns of teaching and b) within the framework of adult development theories. Good teachers in Anaesthesia all identified six characteristics necessary for good teaching. They were characterised by their "inquiry" approach to teaching, their complexity of thought and their functioning at higher relativistic/Commitment levels of epistemological development. Teaching in anaesthesia is depicted by the need to address multiple aspects of thinking and action. Good teachers are aware of these aspects and include techniques that offer residents opportunities to develop their thinking skills to deal with medical complexities as well as guiding learners to increase their knowledge. The interviewed teachers' revealed approaches to teaching and learning that indicated their own personal cognitive complexity and levels of development.

  17. Personality characteristics and sleep variables.

    PubMed

    Nakazawa, Y; Kotorii, M; Arikawa, K; Horikawa, S; Hasuzawa, H

    1975-01-01

    In a sleep study of 14 normal healthy adults an investigation was made of sleep measurements of a baseline record for its eventual relationship to the percentage of increase of REM percentage of the 1st recovery night following partial differential REM deprivation (PDRD), as well as to personality characteristics. The percentage of change in NREM sleep of the 1st recovery night was compared with the baseline record andthen compared with corresponding values of REM sleep. The results are summarized as follows. No significant correlation exists between the percentage of increase in the REM percentage of the 1st recovery night and sleep measures of the baseline record. An investigation of the relationship between sleep measures of the baseline record and personality characteristics revealed that stage SWS(%) was significantly greater in the introvert than in the extrovert, in the neurotic than in the non-neurotic, and in the nervous than in the optimistic. Comparison of the changes in NREM and REM sleep percentages of the 1st recovery night with the baseline record was made between paired personality characteristics. A significantly high percentage of increase in REM percentage was almost always associated with a significantly high percentage of decrease in stage 2 percentage. From these results it was inferred that an increase in REM percentage occurs at the expense of stage 2 percentage.

  18. Statistical characteristics of simulated walls

    NASA Astrophysics Data System (ADS)

    Demiański, M.; Doroshkevich, A. G.; Müller, V.; Turchaninov, V.

    2000-11-01

    The large-scale matter distribution in three different simulations of CDM models is investigated and compared with corresponding results of the Zel'dovich theory of non-linear gravitational instability. We show that the basic characteristics of wall-like structure elements are well described by this theory, and that they can be expressed by the cosmological parameters and a few spectral moments of the perturbation spectrum. Therefore the characteristics of such elements provide reasonable estimates of these parameters. We show that the compressed matter is relaxed and gravitationally confined and manifests itself in the existence of walls as (quasi-)stationary structure elements with a lifetime restricted by their disruption into high-density clouds. The matter distribution is investigated in both real and redshift spaces. In both cases almost the same particles form the walls, and we estimate differences in corresponding wall characteristics. The same methods are applied to several mock catalogues of `galaxies', which allows us to characterize a large-scale bias between the spatial distribution of dark matter and of simulated `galaxies'.

  19. Neurocognitive characteristics of DUI recidivists.

    PubMed

    Ouimet, Marie Claude; Brown, Thomas G; Nadeau, Louise; Lepage, Martin; Pelletier, Marc; Couture, Sophie; Tremblay, Jacques; Legault, Lucie; Dongier, Maurice; Gianoulakis, Christina; Ng Ying Kin, N M K

    2007-07-01

    Individuals who drive under the influence (DUI) of alcohol may be at greater risk for neurocognitive impairment because of their exposure to multiple sources of neurological risk. This could contribute to the persistence of DUI behaviour and influence the effectiveness of remedial interventions. The objectives of this study were to clarify the neurocognitive characteristics of DUI recidivists and the nature of potential impairments, and to explore relationships between these characteristics and the frequency of past DUI convictions. One hundred male recidivists were evaluated for visuospatial constructional abilities and visual memory, verbal fluency, attention skills, cognitive flexibility, spatial planning, and verbal and movement inhibition. Results indicated that a majority of recidivists showed signs of neurocognitive impairment on several dimensions. Impairment was most marked on visuospatial constructional abilities and visual memory. In contrast to previous studies, no participants were found to have impulse control problems. Measures of memory and cognitive efficiency were significantly associated with the frequency of past convictions. Finally, exploratory analyses of two potential sources of impairment, alcohol exposure and head trauma, suggested the role of excessive alcohol use as the most obvious associated factor. Overall, the findings indicate that neurocognitive impairments are a common feature in recidivists and may contribute to DUI persistence. Development of a DUI-specific neurocognitive assessment and greater understanding of how neurocognitive status influences DUI risk could lead to remediation strategies better adapted to the individual characteristics of recidivists.

  20. Characteristics of successful alien plants.

    PubMed

    van Kleunen, M; Dawson, W; Maurel, N

    2015-05-01

    Herbert Baker arguably initiated the search for species characteristics determining alien plant invasion success, with his formulation of the 'ideal weed'. Today, a profusion of studies has tested a myriad of traits for their importance in explaining success of alien plants, but the multiple, not always appropriate, approaches used have led to some confusion and criticism. We argue that a greater understanding of the characteristics explaining alien plant success requires a refined approach that respects the multistage, multiscale nature of the invasion process. We present a schema of questions we can ask regarding the success of alien species, with the answering of one question in the schema being conditional on the answer of preceding questions (thus acknowledging the nested nature of invasion stages). For each question, we identify traits and attributes of species we believe are likely to be most important in explaining species success, and we make predictions as to how we expect successful aliens to differ from natives and from unsuccessful aliens in their characteristics. We organize the findings of empirical studies according to the questions in our schema that they have addressed, to assess the extent to which they support our predictions. We believe that research on plant traits of alien species has already told us a lot about why some alien species become successful after introduction. However, if we ask the right questions at the appropriate scale and use appropriate comparators, research on traits may tell us whether they are really important or not, and if so under which conditions.

  1. 40 CFR 261.24 - Toxicity characteristic.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 26 2014-07-01 2014-07-01 false Toxicity characteristic. 261.24... Toxicity characteristic. (a) A solid waste (except manufactured gas plant waste) exhibits the characteristic of toxicity if, using the Toxicity Characteristic Leaching Procedure, test Method 1311 in...

  2. 40 CFR 261.24 - Toxicity characteristic.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 27 2012-07-01 2012-07-01 false Toxicity characteristic. 261.24... Toxicity characteristic. (a) A solid waste (except manufactured gas plant waste) exhibits the characteristic of toxicity if, using the Toxicity Characteristic Leaching Procedure, test Method 1311 in...

  3. Runoff characteristics of California streams

    USGS Publications Warehouse

    Rantz, S.E.

    1972-01-01

    California streams exhibit a wide range of runoff characteristics that are related to the climatologic, topographic, and geologic characteristics of the basins they drain. The annual volume of runoff of a stream, expressed in inches, may be large or small, and daily discharge rates may be highly variable or relatively steady. The bulk of the annual runoff may be storm runoff, or snowmelt runoff, or a combination of both. The streamflow may be ephemeral, intermittent, or perennial; if perennial, base flow may be well sustained or poorly sustained. In this report the various runoff characteristics are identified by numerical index values. They are shown to be related generally to mean annual precipitation, altitude, latitude, and location with respect to the 11 geomorphic provinces in the California Region. With respect to mean annual precipitation on the watershed, streamflow is generally (1) ephemeral if the mean annual precipitation is less than 10 inches, (2) intermittent if the mean annual precipitation is between 10 and 40 inches, and (3) perennial if the mean annual precipitation is more than 40 inches. Departures from those generalizations are associated with (a) the areal variation of such geologic factors as the infiltration and storage capacities of the rocks underlying the watersheds, and (b) the areal variation of evapotranspiration loss as influenced by varying conditions of climate, soil, vegetal cover, and geologic structure. Latitude and altitude determine the proportion of the winter precipitation that will be stored for subsequent runoff in the late spring and summer. In general, if a watershed has at least 30 percent of its area above the normal altitude of the snowline on April 1, it will have significant snowmelt runoff. Snowmelt runoff in California is said to be significant if at least 30 percent of the annual runoff occurs during the 4 months, April through July. Storm runoff is said to be predominant if at least 65 percent of the annual

  4. [Family characteristics of stuttering children].

    PubMed

    Simić-Ruzić, Budimirka; Jovanović, Aleksandar A

    2008-01-01

    Stuttering is a functional impairment of speech, which is manifested by conscious, but nonintentionally interrupted, disharmonic and disrhythmic fluctuation of sound varying in frequency and intensity. Aetiology of this disorder has been conceived within the frame of theoretical models, which tend to connect genetic and epigenetic factors. The goal of the paper was to study the characteristics of the family functioning of stuttering children in comparison to the family functioning of children without speech disorder, which confirmed the justification of the introduction of family orientated therapeutic interventions into the therapy spectrum of child stuttering. Seventy-nine nucleus families of 3 to 6-year-old children were examined; of these, 39 families had stuttering children and 40 had children without speech disorder. The assessment of family characteristics was made using the Family Health Scale, an observer-rating scale which according to semistructured interview and operational criteria, measures 6 basic dimensions of family functioning: Emotional State, Communication, Borders, Alliances, Adaptability & Stability, Family Skills. A total score calculated from the basic dimensions, is considered as a global index of family health. Families with stuttering children compared to families with children without speech disorder showed significantly lower scores in all the basic dimension of family functioning, as well as in the total score on the Family Health Scale. Our research results have shown that stuttering children in comparison with children without speech disorder live in families with unfavourable emotional atmosphere, impaired communication and worse control over situational and developmental difficulties, which affect children's development and well-being. In the light of previous research, the application of family therapy modified according to the child's needs is now considered indispensable in the therapeutic approach to stuttering children. The

  5. Spectral Characteristics of Titan's Surface

    NASA Astrophysics Data System (ADS)

    Griffith, Caitlin A.; Turner, Jake D.; Penteado, Paulo; Khamsi, Tymon B.; Soderblom, Jason M.

    2014-11-01

    Cassini/Huygens and ground-based measurements of Titan reveal an eroded surface, with lakes, dunes, and sinuous washes. These features, coupled with measurements of clouds and rain, indicate the transfer of methane between Titan’s surface and atmosphere. The presence of methane-damp lowlands suggests further that the atmospheric methane (which is continually depleted through photolysis) may be supplied by sub-surface reservoirs. The byproducts of methane photolysis condense onto the surface, leaving layers of organic sediments that record Titan’s past atmospheres.Thus knowledge of the source and history of Titan's atmosphere requires measurements of the large scale compositional makeup of Titan's surface, which is shrouded by a thick and hazy atmosphere. Towards this goal, we analyzed roughly 100,000 spectra recorded by Cassini’s Visual and Infrared Mapping Spectrometer (VIMS). Our study is confined to the latitude region (20S—20N) surrounding the landing site of the Huygens probe (at 10S, 192W), which supplied only measurement of the vertical profiles of the methane abundance and haze scattering characteristics. VIMS near-IR spectral images indicate subtle latitudinal and temporal variations in the haze characteristics in the tropics. We constrain these small changes with full radiative transfer analyses of each of the thousands of VIMS spectra, which were recorded of different terrains and at different lighting conditions. The resulting models of Titan’s atmosphere as a function of latitude and year indicate the seasonal migration of Titan’s tropical haze and enable the derivation of Titan’s surface albedo at 8 near-IR wavelength regions where Titan’s atmosphere is transparent enough to allow visibility to the surface. The resultant maps of Titan’s surface indicate a number of terrain types with distinct spectral characteristics that are suggestive of atmospheric and surficial processes, including the deposition of organic material, erosion of

  6. Takeoff characteristics of turbofan engines

    SciTech Connect

    Suh, Y.B. )

    1990-05-01

    The present derivation of reliable formulas for the takeoff characteristics of turbofan-powered aircraft, encompassing ground-roll distance and time, fuel consumption, etc, incorporates ground effect-induced drag reduction. This drag reduction factor is varied according to type of aircraft; the turbofans in question may be of high-bypass transport-aircraft type or of low bypass and afterburner-employing configuration, as is typically the case in military aircraft. It is shown that bypass ratio variations have little influence on takeoff ground-rolling distance.

  7. [Exaggerated breed characteristics in dogs].

    PubMed

    Wilting, M M; Endenburg, N

    2012-01-01

    Dutch dog owners seem to be aware of bad dog breeding practices with regard to exaggerated breed characteristics that are detrimental to the dog's welfare. Yet they do not always look for these features when buying a dog. Most dog owners think that veterinarians could have an important role in preventing these exaggerated physical traits, by providing information about these traits and taking action in their capacity as veterinarian. Articles 36 and 55 of the Dutch GWWD (animal health and welfare law) provide opportunities to act against the breeding of dogs with exaggerated genetic traits.

  8. Strain gage adhesives -- Operating characteristics

    NASA Astrophysics Data System (ADS)

    Hannah, R. L.; Reese, R. T.

    1994-02-01

    This paper is concerned with the adhesives which are used to bond the strain gages to substrates. Strain gage installations include four basic parts: the gage, the adhesive used to attach the gage to the stressed surface, the coatings used to protect the gage over its service life, and the electrical circuitry and data acquisition system used to record the strains. This paper describes the operating characteristics of the adhesives. The figures developed in this paper summarize the information available on adhesives from excellent manufacturer's catalogs, texts and references, and from experiences from the SEM Western Regional Strain Gage Committee.

  9. Wellspring characteristics in Rawapening watershed

    NASA Astrophysics Data System (ADS)

    Hafidah, A. D.; Damayanti, A.; Waryono, T.

    2017-07-01

    Rawapening watershed is formed in a volcanic region and is the headwater of Tuntang River that disembogues into Rawa Pening Lake. Rawa Pening Lake was formed due to gravitational tectonic events that form many faults and folds. Those events result in aquifers that create many wellsprings in Rawapening watershed. This research is conducted to determine the wellsprings distribution based on physical characteristics of the discharge area and the types of wellsprings in Rawapening watershed. Associative and descriptive analysis are used to explain the wellsprings' condition based on height, slopeness, geological formation, and the soil utilization.

  10. Inflight lightning characteristics measurement system

    NASA Technical Reports Server (NTRS)

    Pitts, F. L.; Thomas, M. E.; Campbell, R. E.; Thomas, R. M.; Zaepfel, K. P.

    1979-01-01

    A research data-gathering system being developed for inflight measurement of direct and nearby lightning strike characteristics is described. Wideband analog recorders used to record the lightning scenario are supplemented with high-sample-rate digital transient recorders with augmented memory capacity for increased time resolution of specific times of interest. The endless-loop data storage technique employed by the transient recorders circumvents problems associated with oscilloscopic techniques and allows unattended operation. System integrity and immunity from induced effects is accomplished by fiber-optics signal-transmission links, shielded system enclosures, and the use of a dynamotor for power system isolation.

  11. Observational characteristics of explosive events

    NASA Astrophysics Data System (ADS)

    Hénoux, J.-C.; Dere, K. P.

    The characteristics of dynamic phenomena observed in the EUV with the HRTS instruments, chromospheric jets and explosive events, are reviewed here. Most of the review is devoted to explosive events that are short duration explosions involving a plasma at 105 K. These events are characterised by strong Doppler shifts rather than by brightness enhancements, contrary to EUV impulsive brightenings observed by SMM. They are presumably due to magnetic reconnection involving unresolved fine structures of the magnetic field near the network. The role of the density of concentrated magnetic fluxtubes in a reconnection scenario has still to be understood.

  12. Observational characteristics of explosive events.

    NASA Astrophysics Data System (ADS)

    Hénoux, J. C.; Dere, K. P.

    The characteristics of dynamic phenomena observed in the EUV with the HRTS instruments, chromospheric jets and explosive events, are reviewed. Most of the review is devoted to explosive events that are short duration explosions involving a plasma at 105K. These events are characterised by strong Doppler shifts rather than by brightness enhancements, contrary to EUV impulsive brightenings observed by SMM. They are presumably due to magnetic reconnection involving unresolved fine structures of the magnetic field near the network. The role of the density of concentrated magnetic fluxtubes in a reconnection scenario has still to be understood.

  13. Combustion characteristics of husk charcoal

    SciTech Connect

    Shimizu, H.; Kimura, T.; Nishiyama, Y.; Terui, T.

    1984-07-01

    This paper analyzes the factors involved in the extraordinary temperature generation in husk combustion furnaces, and investigates methods of protecting furnaces from heat damage. The combustion characteristics of fixed carbon in rice husks are examined in relation to the air flow rate using different husk charcoals. The theoretical flame temperature in a practical bed was determined from the combustion propagation velocity. It is determined that deviation from the regression line relating the combustion propagation velocity with the specific air flow rate showed a slight correlation with the bulk density of the charcoal samples used.

  14. Geotechnical characteristics of residual soils

    SciTech Connect

    Townsend, F.C.

    1985-01-01

    Residual soils are products of chemical weathering and thus their characteristics are dependent upon environmental factors of climate, parent material, topography and drainage, and age. These conditions are optimized in the tropics where well-drained regions produce reddish lateritic soils rich in iron and aluminum sesquioxides and kaolinitic clays. Conversely, poorly drained areas tend towards montmorillonitic expansive black clays. Andosols develop over volcanic ash and rock regions and are rich in allophane (amorphous silica) and metastable halloysite. The geological origins greatly affect the resulting engineering characteristics. Both lateritic soils and andosols are susceptible to property changes upon drying, and exhibit compaction and strength properties not indicative of their classification limits. Both soils have been used successfully in earth dam construction, but attention must be given to seepage control through the weathered rock. Conversely, black soils are unpopular for embankments. Lateritic soils respond to cement stabilization and, in some cases, lime stabilization. Andosols should also respond to lime treatment and cement treatments if proper mixing can be achieved. Black expansive residual soils respond to lime treatment by demonstrating strength gains and decreased expansiveness. Rainfall induced landslides are typical of residual soil deposits.

  15. Sensitometric characteristics of dental xeroradiography

    SciTech Connect

    Gratt, B.M.; Sickles, E.A.

    1983-11-01

    Dental xeroradiography is a high-quality intraoral imaging system which provides a potentially convenient, rapid, low-dose alternative to conventional film radiography. In this study the sensitometric properties of dental xeroradiography were investigated via assessment of high- and low-contrast xeroradiographic processor settings, transmission versus reflection densitometry, reciprocity-law failure, and kVp (tube voltage) plate dependence. Findings of the study indicated that imaging at high-contrast processor settings results in greater dynamic range but less exposure latitude than imaging at low-contrast processor settings. Determination of characteristic curves demonstrated greater contrast in reflection mode than imaging by transillumination for all but the very densest of images (greater than 1.6 O.D.). There was also little difference in characteristic curves produced from 50 to 90 kVp, indicating that the xeroradiographic plate exhibits a relatively constant sensitivity over the tube voltages tested if exposure is expressed in roentgens. Finally, no substantial reciprocity-law failure was observed for dental xeroradiography over a clinically relevant range of exposure times.

  16. Charge Characteristics of Rechargeable Batteries

    NASA Astrophysics Data System (ADS)

    Maheswaranathan, Ponn; Kelly, Cormac

    2014-03-01

    Rechargeable batteries play important role in technologies today and they are critical for the future. They are used in many electronic devices and their capabilities need to keep up with the accelerated pace of technology. Efficient energy capture and storage is necessary for the future rechargeable batteries. Charging and discharging characteristics of three popular commercially available re-chargeable batteries (NiCd, NiMH, and Li Ion) are investigated and compared with regular alkaline batteries. Pasco's 850 interface and their voltage & current sensors are used to monitor the current through and the potential difference across the battery. The discharge current and voltage stayed fairly constant until the end, with a slightly larger drop in voltage than current, which is more pronounced in the alkaline batteries. After 25 charge/discharge cycling there is no appreciable loss of charge capacities in the Li Ion battery. Energy densities, cycle characteristics, and memory effects will also be presented. Sponsored by the South Carolina Governor's school for Science and Mathematics under the Summer Program for Research Interns program.

  17. Characteristics of spent nuclear fuel

    SciTech Connect

    Notz, K.J.

    1988-04-01

    The Office of Civilian Radioactive Waste Management (OCRWM) is responsible for the spent fuels and other wastes that will, or may, eventually be disposed of in a geological repository. The two major sources of these materials are commercial light-water reactor (LWR) spent fuel and immobilized high-level waste (HLW). Other wastes that may require long-term isolation include non-LWR spent fuels and miscellaneous sources such as activated metals. This report deals with spent fuels, but for completeness, the other sources are described briefly. Detailed characterizations are required for all of these potential repository wastes. These characteristics include physical, chemical, and radiological properties. The latter must take into account decay as a function of time. In addition, the present inventories and projected quantities of the various wastes are needed. This information has been assembled in a Characteristics Data Base which provides data in four formats: hard copy standard reports, menu-driven personal computer (PC) data bases, program-level PC data bases, and mainframe computer files. 5 refs., 3 figs., 4 tabs.

  18. Psychiatric characteristics of homicide defendants.

    PubMed

    Martone, Christine A; Mulvey, Edward P; Yang, Suzanne; Nemoianu, Andrei; Shugarman, Ryan; Soliman, Layla

    2013-09-01

    The authors examined the rate of mental disorders in an unselected sample of homicide defendants in a U.S. jurisdiction, seeking to identify psychiatric factors associated with offense characteristics and court outcomes. Defendants charged with homicide in a U.S. urban county between 2001 and 2005 received a psychiatric evaluation after arrest. Demographic, historical, and psychiatric variables as well as offense characteristics and legal outcomes were described. Bivariate analyses examined differences by age group and by race, and logistic models examined predictors of multiple victims, firearm use, guilty plea, and guilty verdict. Fifty-eight percent of the sample had at least one axis I or II diagnosis, most often a substance use disorder (47%). Axis I or II diagnoses were more common (78%) among defendants over age 40. Although 37% of the sample had prior psychiatric treatment, only 8% of the defendants with diagnosed axis I disorders had outpatient treatment during the 3 months preceding the homicide; African Americans were less likely than non-African Americans to be in treatment. African American males were more likely to use a firearm and to have a male victim. In exploratory analyses, psychiatric factors did not predict multiple victims, firearm use in the crime, or a guilty verdict. Rates of axis I disorders were lower than reported in previous studies. Few homicide defendants were in psychiatric treatment at the time of the crime, suggesting limited opportunities for prevention by mental health providers.

  19. Sampling characteristics of satellite orbits

    NASA Technical Reports Server (NTRS)

    Wunsch, Carl

    1989-01-01

    The irregular space-time sampling of any finite region by an orbiting satellite raises difficult questions as to which frequencies and wavenumbers can be determined and which will alias into others. Conventional sampling theorems must be extended to account for both irregular data distributions and observational noise - the sampling irregularity making the system much more susceptible to noise than in regularly sampled cases. The problem is formulated here in terms of least-squares and applied to spacecraft in 10-day and 17-day repeating orbits. The 'diamond-pattern' laid down spatially in such repeating orbits means that either repeat period adequately samples the spatial variables, but the slow overall temporal coverage in the 17-day pattern leads to much greater uncertainty than in the shorter repeat cycle. The result is not definitive and it is not concluded that a 10-day orbit repeat is the most appropriate one. A major conclusion, however, is that different orbital choices have potentially quite different sampling characteristics which need to be analyzed in terms of the spectral characteristics of the moving sea surface.

  20. The characteristics of pneumatic piston drive

    NASA Astrophysics Data System (ADS)

    Bracha, Gabriel F.

    The article presents a study on the rodless pneumatic piston actuator. Mathematical model of the pneumatic actuator, static and dynamic characteristics are obtained and compared with the real drive characteristics.

  1. The characteristics of a pneumatic muscle

    NASA Astrophysics Data System (ADS)

    Pietrala, Dawid

    The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics). It presents characteristics showing the relationship of pneumatic muscles shortening and values of loading forces, at a constant operational pressure (isobaric characteristics). It also shows the dependence of force generated by the muscle on the operating pressure, at a constant value of pneumatic muscles shortening (isometric characteristics). The paper also presents dynamic characteristics of a pneumatic muscle showing the response of an object to a gradual change in the operating pressure, at a constant loading force acting on the pneumatic muscle.

  2. 30 CFR 7.45 - Critical characteristics

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Battery Assemblies § 7.45 Critical characteristics The following critical characteristics shall be inspected or tested on each battery assembly...

  3. 30 CFR 7.305 - Critical characteristics.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Electric Motor Assemblies § 7.305 Critical characteristics. The following critical characteristics shall be inspected on each motor assembly to which an...

  4. 30 CFR 7.305 - Critical characteristics.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Electric Motor Assemblies § 7.305 Critical characteristics. The following critical characteristics shall be inspected on each motor assembly to which an...

  5. Effect of Nanofiller Characteristics on Nanocomposite Properties

    NASA Technical Reports Server (NTRS)

    Working, Dennis C.; Lillehei, Peter T.; Lowther, Sharon E.; Siochi, Emilie J.; Kim, Jae-Woo; Sauti, Godfrey; Wise, Kristopher E.; Park, Cheol

    2016-01-01

    This report surveys the effect of nanofiller characteristics on nanocomposites fabricated with two polyimide matrices. Mechanical and electrical properties were determined. Microscopy results showed that matrix chemistry, nanofiller characteristics and processing conditions had significant impact on nanocomposite quality.

  6. The characteristics of pneumatic piston drive

    NASA Astrophysics Data System (ADS)

    Bracha, Gabriel F.

    2016-11-01

    The article presents a study on the rodless pneumatic piston actuator. Mathematical model of the pneumatic actuator, static and dynamic characteristics are obtained and compared with the real drive characteristics.

  7. 30 CFR 7.305 - Critical characteristics.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Electric Motor Assemblies § 7.305 Critical characteristics. The following critical characteristics shall be inspected on each motor assembly to which...

  8. 30 CFR 7.305 - Critical characteristics.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Electric Motor Assemblies § 7.305 Critical characteristics. The following critical characteristics shall be inspected on each motor assembly to which...

  9. 30 CFR 7.305 - Critical characteristics.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Electric Motor Assemblies § 7.305 Critical characteristics. The following critical characteristics shall be inspected on each motor assembly to which...

  10. [Kleptomania: clinical characteristics and treatment].

    PubMed

    Grant, Jon E; Odlaug, Brian L

    2008-05-01

    Kleptomania, a disabling impulse control disorder, is characterized by the repetitive and uncontrollable theft of items that are of little use to the afflicted person. Despite its relatively long history, kleptomania remains poorly understood to the general public, clinicians, and sufferers. This article reviews the literature for what is known about the clinical characteristics, family history, neurobiology, and treatment options for individuals with kleptomania. Kleptomania generally has its onset in late adolescence or early adulthood and appears to be more common among women. Lifetime psychiatric comorbidity is frequent, mainly with other impulse control (20-46%), substance use (23-50%) and mood disorders (45-100%). Individuals with kleptomania suffer significant impairment in their ability to function socially and occupationally. Kleptomania may respond to cognitive behavioral therapy and various pharmacotherapies (lithium, anti-epileptics, and opioid antagonists). Kleptomania is a disabling disorder that results in intense shame, as well as legal, social, family, and occupational problems. Large scale treatment studies are needed.

  11. Molecular characteristics versus biological activity

    USGS Publications Warehouse

    Applegate, Vernon C.; Smith, Manning A.; Willeford, Bennett R.

    1967-01-01

    The molecular characteristics of mononitrophenols containing halogens not only play a key role in their biological activity but provide a novel example of selective toxicity among vertebrate animals. It has been reported that efforts to control the parasitic sea lamprey in the Great Lakes are directed at present to the applications of a selective toxicant to streams inhabited by lamprey larvae. Since 1961, the larvicide that has been used almost exclusively in the control program has been 3-trifluoromethyl-4-nitrophenol (TFM). However, this is only one of about 15 closely related compounds, all halogen-containing mononitrophenols, that display a selectively toxic action upon lampreys. Although not all of the halogenated mononitrophenols are selectively toxic to lampreys (in fact, fewer than half of those tested), no other group of related compounds has displayed any useful larvicidal activity except for the substituted nitrosalicylanilides.

  12. Characteristics of Older Motorcyclist Crashes

    PubMed Central

    Stutts, Jane; Foss, Robert; Svoboda, Colleen

    2004-01-01

    In the U.S. as well as other countries, the number of motorcyclists killed in traffic crashes has risen sharply over the past five years, due in part to the increased popularity of motorcycling among older riders. This paper examines trends in motorcyclist casualties and vehicle registrations from 1990–2002, based on national and state (North Carolina) motor vehicle crash and vehicle registration data. The data show similar patterns of increased fatalities that parallel a growth in motorcycle registrations. Whereas the number of motorcyclists ages 16–24 declined over the 13–year study period, the number of riders ages 35 and older increased. Three years of recent (2000–2002) NC data are examined to identify salient characteristics of the crashes of these older riders. Results are discussed with respect to approaches for mitigating the increase in motorcyclist deaths and injuries. PMID:15319126

  13. Personality characteristics of Wikipedia members.

    PubMed

    Amichai-Hamburger, Yair; Lamdan, Naama; Madiel, Rinat; Hayat, Tsahi

    2008-12-01

    Wikipedia is an online, free access, volunteer-contributed encyclopedia. This article focuses on the Wikipedians' (Wikipedia users) personality characteristics, studying Wikipedians' conceptions of Real-Me and BFI dimensions. To survey these aspects, we posted links to two online web questionnaires; one was targeted at Wikipedians and the second to non-Wikipedia users. One hundred and thirty-nine subjects participated in the study, of which 69 were active Wikipedia members. It was found that Wikipedia members locate their real me on the Internet more frequently as compared to non-Wikipedia members. Variance analysis revealed significant differences between Wikipedia members and non-Wikipedia members in agreeableness, openness, and conscientiousness, which were lower for the Wikipedia members. An interaction was found between Wikipedia membership and gender: introverted women were more likely to be Wikipedia members as compared with extroverted women. The results of this study are discussed with special emphasis on the understanding of the motivators of Wikipedia members.

  14. Thermal Characteristics of Heating Towers

    NASA Astrophysics Data System (ADS)

    Fujita, Toshihiko; Kametani, Shigeki

    Thermal characteristics of heating towers for air-source heat pumps are studied in terms of the overall enthalpy-transfer coefficient. Ka. First. the method of counter-flow calculation is presented taking physical properties of ethylene glycol solutions into account. Next, both cooling-tower and heating-tower experiments are carried out in a small, induced-draft. counterflow tower packed with tubes of a staggerd arrangement. using water and commercial ethylene glycol solutions. The coefficient Ka measured in the heating-tower experiment shows a trend similar to that in the cooling-tower experiment. So. the data on cooling towers will be helpful to the thermal design of heating towers.

  15. Doppler characteristics of sea clutter.

    SciTech Connect

    Raynal, Ann Marie; Doerry, Armin Walter

    2010-06-01

    Doppler radars can distinguish targets from clutter if the target's velocity along the radar line of sight is beyond that of the clutter. Some targets of interest may have a Doppler shift similar to that of clutter. The nature of sea clutter is different in the clutter and exo-clutter regions. This behavior requires special consideration regarding where a radar can expect to find sea-clutter returns in Doppler space and what detection algorithms are most appropriate to help mitigate false alarms and increase probability of detection of a target. This paper studies the existing state-of-the-art in the understanding of Doppler characteristics of sea clutter and scattering from the ocean to better understand the design and performance choices of a radar in differentiating targets from clutter under prevailing sea conditions.

  16. Characteristics of coking coal burnout

    SciTech Connect

    Nakamura, M.; Bailey, J.G.

    1996-12-31

    An attempt was made to clarify the characteristics of coking coal burnout by the morphological analysis of char and fly ash samples. Laboratory-scale combustion testing, simulating an ignition process, was carried out for three kinds of coal (two coking coals and one non-coking coal for reference), and sampled chars were analyzed for size, shape and type by image analysis. The full combustion process was examined in industrial-scale combustion testing for the same kinds of coal. Char sampled at the burner outlet and fly ash at the furnace exit were also analyzed. The difference between the char type, swelling properties, agglomeration, anisotropy and carbon burnout were compared at laboratory scale and at industrial scale. As a result, it was found that coking coals produced chars with relatively thicker walls, which mainly impeded char burnout, especially for low volatile coals.

  17. Acoustic characteristics of twin jets.

    PubMed

    He, F; Zhang, X W

    2002-09-01

    Experiments were conducted to investigate the acoustic characteristics of underexpanded supersonic twin jets in different azimuthal measurement planes. Compared with two independent jets, the twin jets produced additional noise due to the enhanced mixing and entrainment. The larger pressure ratio for switching from the axisymmetric mode to the helical mode led to lower noise levels at 90 degrees than for two independent jets. For pressure ratios greater than 5.00, the noise reduction was due to cessation of screeching of the twin jets while screeching of a single jet was still detected. The apparent shielding phenomenon was measured for the screech helical mode. The screech tone intensities were attenuated largely due to the shielding effects. The noise reductions due to shielding were obtained over a wide range of pressure ratios relative to the sum of two independent jets.

  18. Pathophysiologic characteristics of hypovolemic shock.

    PubMed

    Moore, K E; Murtaugh, R J

    2001-11-01

    In the late 1800s, while caring for a trauma victim, Warren characterized shock as "a momentary pause in the act of death." A great deal about shock has been discovered since this first description. Dorland's Medical Dictionary defines shock as a condition of profound hemodynamic and metabolic disturbance characterized by failure of the circulatory system to maintain adequate perfusion of vital organs. Shock is now being defined at the cellular level as the inadequate delivery of nutrients to the cells of the body. Because oxygen is the only nutrient that cells cannot store in any appreciable quantity, shock is also equivalent to inadequate oxygen delivery (DO2). Although there are many types of shock, this article concentrates on the pathophysiologic characteristics of hypovolemic shock.

  19. Characteristics of Mycoplasma hominis adhesion.

    PubMed Central

    Olson, L D; Gilbert, A A

    1993-01-01

    Mycoplasma hominis, a human pathogen, has previously been observed to bind to sulfatide separated on thin-layer chromatograms. It has not been demonstrated, however, that the binding is not simply a nonspecific ionic interaction. The ability of a low-passage patient isolate of M. hominis to adhere to glycoconjugates other than sulfatide and the characteristics of its binding to sulfatide were studied. Mycoplasmas were found to bind strongly and specifically in a temperature- and dose-dependent manner to only sulfatide of all of the glycolipids and glycoproteins tested. The avidity and specificity of binding, as well as the ability to inhibit the interaction specifically, suggest that the receptors to which M. hominis binds, particularly in the human urogenital tract, from which it is frequently isolated, are primarily, if not solely, sulfated glycolipids. Images PMID:8491739

  20. Characteristic dermoscopic features of melasma.

    PubMed

    Li, Yun; Liu, Jie; Sun, Qiu-ning

    2015-04-01

    To discribe the characteristic dermoscopic features of melasma. Totally 20 patients with typical clinical presentations of melasma were included in this study. The melasma lesion and its surrounding normal skin were evaluated using dermatoscope. Melasma lesions manifested light yellow brown uniform patches in all patients, among whom dark brown patches were found in 19 patients, capillary network in 14 patients,and coarse hair in 6 patients. In contrast, no light yellow brown uniform patch was found in the normal skin in all patients (P<0.001), among whom dark brown patches were found in 10 patients (P<0.001), capillary network in 12 patients (P>0.05), and coarse hair in 2 patients (P>0.05). Light yellow brown uniform patches and dark brown patches are two major dermoscopic features of melasma.

  1. Compressor and fan wake characteristics

    NASA Technical Reports Server (NTRS)

    Reynolds, B.; Hah, C.; Lakshminarayana, B.; Ravindranath, A.

    1978-01-01

    A triaxial probe and a rotating conventional probe, mounted on a traverse gear operated by two step motors were used to measure the mean velocities and turbulence quantities across a rotor wake at various radial locations and downstream stations. The data obtained was used in an analytical model developed to study how rotor flow and blade parameters and turbulence properties such as energy, velocity correlations, and length scale affect the rotor wake characteristics and its diffusion properties. The model, includes three dimensional attributes, can be used in predicting the discrete as well as broadband noise generated in a fan rotor, as well as in evaluating the aerodynamic losses, efficiency and optimum spacing between a rotor and stator in turbomachinery.

  2. Characteristics of Myosin V Processivity.

    PubMed

    Zhang, Jun-Ping; Liu, Yi; Sun, Wei; Zhao, Xiaoyang; La, Ta; Guo, Wei-Sheng

    2017-02-14

    Myosin V is a processive doubled-headed biomolecular motor involved in many intracellular organelle and vesicle transport. The unidirectional movement is coupled with the adenosine triphosphate (ATP) hydrolysis and product release cycle. With the progress of experimental techniques and the enhancement of measuring directness, detailed knowledge of the motility of myosin V has been obtained.Following the ATPase cycle, the 4-state mechanochemical model of the myosin V's processive movement is used. The transitions between various states take place in a stochastic manner. We can use the master equation to analyze and calculate quantitatively. Meanwhile the effect of the reverse reaction is takenfully into account. We fit the mean velocity, the mean dwell time, the mean run length andtheratio of forward/backward steps as a functionof ATP, ADP and Pi concertration. The theoretical curves are generally in line with the experimental data. This work provides a new insight for the characteristic of myosin V.

  3. A solar cell characteristics plotter

    NASA Astrophysics Data System (ADS)

    Lam, Y. W.

    1981-11-01

    This paper describes a solar-cell characteristics plotter with its associated sample holder. The plotter has facilities for both manual and auto-plotting, with built-in current limit against damage of the solar cell under test. Either current or power output can be plotted as a function of terminal voltage, and there is provision for marking the maximum power point on the curve. The sample holder allows the temperature of the solar cell to be varied over a range from approximately -188 to 250 C and permits investigation of other properties of materials used in the making of the solar cell, e.g. the antireflection layer. If temperature variation is not required the holder can be water cooled to prevent overheating of the solar cell during test. The plotter can also be used for the investigation of other semiconductor devices, and is ideal for use in small research and development laboratories.

  4. Characteristic Time Scales of Characteristic Magmatic Processes and Systems

    NASA Astrophysics Data System (ADS)

    Marsh, B. D.

    2004-05-01

    Every specific magmatic process, regardless of spatial scale, has an associated characteristic time scale. Time scales associated with crystals alone are rates of growth, dissolution, settling, aggregation, annealing, and nucleation, among others. At the other extreme are the time scales associated with the dynamics of the entire magmatic system. These can be separated into two groups: those associated with system genetics (e.g., the production and transport of magma, establishment of the magmatic system) and those due to physical characteristics of the established system (e.g., wall rock failure, solidification front propagation and instability, porous flow). The detailed geometry of a specific magmatic system is particularly important to appreciate; although generic systems are useful, care must be taken to make model systems as absolutely realistic as possible. Fuzzy models produce fuzzy science. Knowledge of specific time scales is not necessarily useful or meaningful unless the hierarchical context of the time scales for a realistic magmatic system is appreciated. The age of a specific phenocryst or ensemble of phenocrysts, as determined from isotopic or CSD studies, is not meaningful unless something can be ascertained of the provenance of the crystals. For example, crystal size multiplied by growth rate gives a meaningful crystal age only if it is from a part of the system that has experienced semi-monotonic cooling prior to chilling; crystals entrained from a long-standing cumulate bed that were mechanically sorted in ascending magma may not reveal this history. Ragged old crystals rolling about in the system for untold numbers of flushing times record specious process times, telling more about the noise in the system than the life of typical, first generation crystallization processes. The most helpful process-related time scales are those that are known well and that bound or define the temporal style of the system. Perhaps the most valuable of these

  5. Spent fuel characteristics & disposal considerations

    SciTech Connect

    Oversby, V.M.

    1996-06-01

    The fuel used in commercial nuclear power reactors is uranium, generally in the form of an oxide. The gas-cooled reactors developed in England use metallic uranium enclosed in a thin layer of Magnox. Since this fuel must be processed into a more stable form before disposal, we will not consider the characteristics of the Magnox spent fuel. The vast majority of the remaining power reactors in the world use uranium dioxide pellets in Zircaloy cladding as the fuel material. Reactors that are fueled with uranium dioxide generally use water as the moderator. If ordinary water is used, the reactors are called Light Water Reactors (LWR), while if water enriched in the deuterium isotope of hydrogen is used, the reactors are called Heavy Water reactors. The LWRs can be either pressurized reactors (PWR) or boiling water reactors (BWR). Both of these reactor types use uranium that has been enriched in the 235 isotope to about 3.5 to 4% total abundance. There may be minor differences in the details of the spent fuel characteristics for PWRs and BWRs, but for simplicity we will not consider these second-order effects. The Canadian designed reactor (CANDU) that is moderated by heavy water uses natural uranium without enrichment of the 235 isotope as the fuel. These reactors run at higher linear power density than LWRs and produce spent fuel with lower total burn-up than LWRs. Where these difference are important with respect to spent fuel management, we will discuss them. Otherwise, we will concentrate on spent fuel from LWRs.

  6. Psychological characteristics of BDSM practitioners.

    PubMed

    Wismeijer, Andreas A J; van Assen, Marcel A L M

    2013-08-01

    It has been generally thought that the practice of bondage-discipline, dominance-submission, sadism-masochism (BDSM) is in some form associated with psychopathology. However, several more recent studies suggest a relative good psychological health of BDSM practitioners. The aim of this study was to compare scores of BDSM practitioners and a control group on various fundamental psychological characteristics. For this aim, 902 BDSM and 434 control participants completely filled out online questionnaires. Associations were examined using χ(2) tests of independence with φ and Cramer's V as effect size measures and eta or Pearson's correlation. Group differences were tested using analysis of covariance, with partial η(2) as effect size measure. A priori contrasts were tested using α = 0.01 to correct for multiple testing; for all other tests we used α = 0.05, two tailed. The study used Big Five personality dimensions (NEO Five-Factor Inventory), attachment styles (Attachment Styles Questionnaire), rejection sensitivity (Rejection Sensitivity Questionnaire), and subjective well-being (World Health Organization-Five Well-being Index). The results mostly suggest favorable psychological characteristics of BDSM practitioners compared with the control group; BDSM practitioners were less neurotic, more extraverted, more open to new experiences, more conscientious, less rejection sensitive, had higher subjective well-being, yet were less agreeable. Comparing the four groups, if differences were observed, BDSM scores were generally more favorably for those with a dominant than a submissive role, with least favorable scores for controls. We conclude that BDSM may be thought of as a recreational leisure, rather than the expression of psychopathological processes. © 2013 International Society for Sexual Medicine.

  7. Characteristic length of glass transition

    NASA Astrophysics Data System (ADS)

    Donth, E.

    1996-03-01

    The characteristic length of the glass transition (ξ _α ) is based on the concept of cooperatively rearranging regions (CRR's) by Adam & Gibbs (1965): ξ _α is the diameter of one CRR. In the theoretical part of the talk a formula is derived how this length can be calculated from calorimetric data of the transformation interval. The approach is based on fluctuations in natural functional subsystems. The corresponding thermodynamics is represented e.g. in a book of the author (E. Donth, Relaxation and Thermodynamics in Polymers. Glass Transition, Akademie-Verlag, Berlin 1992). A typical value for this length is 3 nanometers. In the experimental part several examples are reported to enlarge the experimental evidence for such a length: Squeezing the glass transition in the amorphous layers of partially crystallized PET (C. Schick, Rostock), glass transition of small-molecule glass formers in a series of nanoscaled pores of porous glasses (F. Kremer, Leipzig), comparison with a concentration fluctuation model in homogeneous polymer mixtures (E.W. Fischer, Mainz), and, from our laboratory, backscaling to ξ _α across the main transition from the entanglement spacing in several amorphous polymers such as PVAC, PS, NR, and some polymer networks. Rouse backscaling was possible in the α β splitting region of several poly(n alkyl methacrylates) resulting in small characteristic lengths of order 1 nanometer near the onset of α cooperativity. In a speculative outlook a dynamic density pattern is presented, having a cellular structure with higher density and lower mobility of the cell walls. It will be explained, with the aid of different thermal expansion of wall and clusters, how the clusters within the cells maintain a certain mobility far below the glass temperature.

  8. [Characteristics of postpartum thyroid dysfunction].

    PubMed

    Argatska, A; Nonchev, B; Obretsova, M; Pehlivanov, B

    2015-01-01

    The risk factors and mechanisms for the development of postpartum thyroid dysfunction have been widely discussed. However data on patients suffered spontaneous or induced abortion during early pregnancy are scarce. To reveal the characteristics of thyroid dysfunction in women after an abortion in the first trimester of pregnancy. A total of 28 women (18 euthyroid, 10 with thyroid dysfunction), mean age 30.46 ± 1.01 years following abortion in the first trimester have been included in the study. Thyroid-stimulating hormone (TSH), free triiodthyronine (FT3), free thyroxine (FT4), thyreoglobulin antibodies (TgAb), thyroid peroxidase antibodies (TPOAb) were measured and ultrasound assessment of the thyroid was performed 3 and 9 months after the interruption of pregnancy. Hypothyroidism was found in 6 of the women with thyroid dysfunction and thyrotoxicosis--in 4. Clinical features of thyroid dysfunction were observed in 3 patients while in the remaining 7 cases, diagnosis was made on the basis of hormonal levels. Positive titers of thyroid autoantibodies were detected in the majority of the cases with functional disordes. In 6 patients thyroid dysfunction was transient and in 4 hormonal abnormalities persisted on by the 9th month after the abortion. The comparative analysis showed that the volume of the thyroid gland and the degree of hypoehogenicity were significantly higher in patients with thyroid dysfunction compared to euthyroid women. Thyroid dysfunction after abortion in the first trimester is mainly of autoimmune pathogenesis and its characteristics do not differ from those of postpartum thyroiditis. In the majority of patients these disorders are subclinical and may remain unrecognized. A close active follow up of patients at increased risk of functional thyroid disorders after an abortion is required in order to prevent morbidity and identify the cases developing permanent thyroid dysfunction.

  9. ILLIAC 4 systems characteristics and programming manual

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The latest edition is presented of the Systems Characteristics and Programming Manual of the ILLIAC 4 array and parallel disc memory system. The major aspects of the array described include: the array systems characteristics, programming characteristics, definition and flow charts, and timing. A glossary of terms, and an instruction index are included.

  10. F-5-L Boat Seaplane : performance characteristics

    NASA Technical Reports Server (NTRS)

    Diehl, W S

    1922-01-01

    Performance characteristics for the F-5-L Boat Seaplane are given. Characteristic curves for the RAF-6 airfoil and the F-5-L wings, parasite resistance and velocity data, engine and propeller characteristics, effective and maximum horsepower, and cruising performance are discussed.

  11. Characteristics of High-Performing School Districts

    ERIC Educational Resources Information Center

    Leithwood, Kenneth; Azah, Vera N.

    2017-01-01

    This mixed-methods study inquired about characteristics of districts which influence changes in student achievement and how those characteristics are developed. Staff in 49 Ontario districts were surveyed to estimate the status of nine district characteristics on changes in provincial tests of math and language achievement over five years. A…

  12. Characteristics of High-Performing School Districts

    ERIC Educational Resources Information Center

    Leithwood, Kenneth; Azah, Vera N.

    2017-01-01

    This mixed-methods study inquired about characteristics of districts which influence changes in student achievement and how those characteristics are developed. Staff in 49 Ontario districts were surveyed to estimate the status of nine district characteristics on changes in provincial tests of math and language achievement over five years. A…

  13. Tier identification (TID) for tiered memory characteristics

    DOEpatents

    Chang, Jichuan; Lim, Kevin T; Ranganathan, Parthasarathy

    2014-03-25

    A tier identification (TID) is to indicate a characteristic of a memory region associated with a virtual address in a tiered memory system. A thread may be serviced according to a first path based on the TID indicating a first characteristic. The thread may be serviced according to a second path based on the TID indicating a second characteristic.

  14. Approximating the efficiency characteristics of blade pumps

    NASA Astrophysics Data System (ADS)

    Shekun, G. D.

    2007-11-01

    Results from a statistical investigation into the experimental efficiency characteristics of commercial type SD centrifugal pumps and type SDS swirl flow pumps are presented. An exponential function for approximating the efficiency characteristics of blade pumps is given. The versatile nature of this characteristic is confirmed by the fact that the use of different systems of relative units gives identical results.

  15. Characteristics of cardiac troponin measurements.

    PubMed

    Christenson, Eric; Christenson, Robert H

    2013-12-01

    Cardiac troponin I (cTnI) and T (cTnT) have displaced myoglobin and creatine kinase-MB as the preferred markers of myocardial injury and have become the cornerstones for diagnosis of myocardial infarction (MI). Current guidelines for MI diagnosis give specific recommendations for cTnI and cTnT assays including instructions to reliably measure values in the range of the 99th percentile of a normal reference cohort with good precision, for example, 10% total coefficient of variation. Unfortunately, the nomenclature system that has evolved for cTnI and cTnT is haphazard and unsystematic. It is key to recognize that not all cTnI and cTnT measurement methods are equivalent; hence, knowledge of local measurements is essential for effective evaluation of patients presenting with suspected non-ST elevation MI. For cTnI, the amino acid sequences frequently targeted for effective measurement include residues 41-49 and 83-93 because these regions of the molecule are stable, helping make the assays reproducible. Use of the recommended cutoff at the 99th percentile of a normal cohort is related to improved patient outcomes. Therefore, use of a troponin assay with good measurement characteristics at the 99th percentile, often referred to as 'sensitive assays', is important for patient outcomes. cTnI and cTnT assays with higher sensitivity are becoming available, and their utilization for measurement in asymptomatic populations may be useful for risk assessment and management in the future. However there is currently no evidence that these high-sensitivity assays confer an advantage in the context of MI diagnosis. Currently cTnI assays are not standardized; thus, there can be a substantial difference in values depending on the assay used. An international effort toward standardization is ongoing, but is not anticipated to be completed and implemented for a few years. Our purpose here is to add insight to important characteristics of troponin measurement techniques and how these

  16. Permeation characteristics of gramicidin conformers.

    PubMed Central

    Busath, D; Szabo, G

    1988-01-01

    To investigate the molecular origin of decreased conductance in variant gramicidin channels, we examined the current-voltage (IV) characteristics of single Val1-gramicidin A channels. Unlike standard channels, all variant channels showed pronounced rectification even though bathing solutions were symmetrical. Moreover, channels of lower conductance consistently showed more pronounced rectification. Analysis within the framework of a three-barrier, two-site, single-filing model indicates that the shape of the variant channel IVs could be best explained by an increase in binding affinity near one of the two channel entrances. This conclusion was further tested by characterizing single channel IVs in bi-ionic solutions having different cationic species at each channel entrance. In Cs/Na bi-ionic solutions, reversal potentials of variant channels often differed by a small but significant amount from those of standard channels. When a membrane potential was applied, the ionic currents tended to be reduced more when flowing from the Na+ side than the Cs+ side. These observations support the conclusion that variant channels have increased binding affinity at one end of the channel. Furthermore, H+ currents were increased while Ag+ currents were unaltered for most variant channels exhibiting decreased Na+ or Cs+ currents. The increased H+ conductance argues against long-range coulombic forces as the basis for decreased Na+ or Cs+ conductance while the normal Ag+ conductance suggests that the binding site field strength increases by a change in carbonyl geometry at the channel entrance. PMID:2455549

  17. Stationary Plasma Thruster Plume Characteristics

    NASA Technical Reports Server (NTRS)

    Myers, Roger M.; Manzella, David H.

    1994-01-01

    Stationary Plasma Thrusters (SPT's) are being investigated for application to a variety of near-term missions. This paper presents the results of a preliminary study of the thruster plume characteristics which are needed to assess spacecraft integration requirements. Langmuir probes, planar probes, Faraday cups, and a retarding potential analyzer were used to measure plume properties. For the design operating voltage of 300 V the centerline electron density was found to decrease from approximately 1.8 x 10 exp 17 cubic meters at a distance of 0.3 m to 1.8 X 10 exp 14 cubic meters at a distance of 4 m from the thruster. The electron temperature over the same region was between 1.7 and 3.5 eV. Ion current density measurements showed that the plume was sharply peaked, dropping by a factor of 2.6 within 22 degrees of centerline. The ion energy 4 m from the thruster and 15 degrees off-centerline was approximately 270 V. The thruster cathode flow rate and facility pressure were found to strongly affect the plume properties. In addition to the plume measurements, the data from the various probe types were used to assess the impact of probe design criteria

  18. Imaging characteristics of indinavir calculi.

    PubMed

    Schwartz, B F; Schenkman, N; Armenakas, N A; Stoller, M L

    1999-04-01

    Indinavir sulfate is an effective protease inhibitor of the human immunodeficiency virus type 1. Use is associated with a significant incidence of crystallization and stone formation in the urinary tract, and these calculi are not visible on plain radiographs. Previously all urinary stones, including uric acid and matrix, were believed to be radiodense on computerized tomography (CT). We conducted a retrospective study to evaluate the radiographic appearance of indinavir calculi. Retrospective chart review of 36 patients taking indinavir sulfate and presenting with renal colic was performed with attention to presentation, urinalysis, radiographic evaluation and management. Specifically, imaging characteristics on CT were addressed. All patients complained of ipsilateral flank pain and 35 had nausea and/or vomiting. Of 30 patients with dysuria or urgency the majority had hematuria, and most had pyuria and/or proteinuria. No stones were visualized on abdominal radiography. Diagnosis was confirmed on 1 of 13 excretory urograms and 4 of 11 renal ultrasounds. None of 12 CT scans was diagnostic of renal lithiasis. Indinavir sulfate is a protease inhibitor with poor solubility and significant urinary excretion. Crystallization and stone formation are demonstrated in as many as 20% of patients taking the medication. Most patients present with flank pain, nausea or vomiting and hematuria. Previously CT was thought to identify all urinary calculi with clarity but it cannot reliably confirm the presence of indinavir calculi.

  19. X-34 Vehicle Aerodynamic Characteristics

    NASA Technical Reports Server (NTRS)

    Brauckmann, Gregory J.

    1998-01-01

    The X-34, being designed and built by the Orbital Sciences Corporation, is an unmanned sub-orbital vehicle designed to be used as a flying test bed to demonstrate key vehicle and operational technologies applicable to future reusable launch vehicles. The X-34 will be air-launched from an L-1011 carrier aircraft at approximately Mach 0.7 and 38,000 feet altitude, where an onboard engine will accelerate the vehicle to speeds above Mach 7 and altitudes to 250,000 feet. An unpowered entry will follow, including an autonomous landing. The X-34 will demonstrate the ability to fly through inclement weather, land horizontally at a designated site, and have a rapid turn-around capability. A series of wind tunnel tests on scaled models was conducted in four facilities at the NASA Langley Research Center to determine the aerodynamic characteristics of the X-34. Analysis of these test results revealed that longitudinal trim could be achieved throughout the design trajectory. The maximum elevon deflection required to trim was only half of that available, leaving a margin for gust alleviation and aerodynamic coefficient uncertainty. Directional control can be achieved aerodynamically except at combined high Mach numbers and high angles of attack, where reaction control jets must be used. The X-34 landing speed, between 184 and 206 knots, is within the capabilities of the gear and tires, and the vehicle has sufficient rudder authority to control the required 30-knot crosswind.

  20. X-33 Hypersonic Aerodynamic Characteristics

    NASA Technical Reports Server (NTRS)

    Murphy, Kelly J.; Nowak, Robert J.; Thompson, Richard A.; Hollis, Brian R.; Prabhu, Ramadas K.

    1999-01-01

    Lockheed Martin Skunk Works, under a cooperative agreement with NASA, will build and fly the X-33, a half-scale prototype of a rocket-based, single-stage-to-orbit (SSTO), reusable launch vehicle (RLV). A 0.007-scale model of the X-33 604B0002G configuration was tested in four hypersonic facilities at the NASA Langley Research Center to examine vehicle stability and control characteristics and to populate an aerodynamic flight database i n the hypersonic regime. The vehicle was found to be longitudinally controllable with less than half of the total body flap deflection capability across the angle of attack range at both Mach 6 and Mach 10. At these Mach numbers, the vehicle also was shown to be longitudinally stable or neutrally stable for typical (greater than 20 degrees) hypersonic flight attitudes. This configuration was directionally unstable and the use of reaction control jets (RCS) will be necessary to control the vehicle at high angles of attack in the hypersonic flight regime. Mach number and real gas effects on longitudinal aerodynamics were shown to be small relative to X-33 control authority.

  1. Temporal Characteristics of Otoacoustic Emissions

    NASA Astrophysics Data System (ADS)

    Withnell, R. H.; Dhar, S.; Talmadge, C. L.; Shaffer, L. A.; de Boer, E.; Roberts, R.; McPherson, D.

    2003-02-01

    The recent work of Talmadge et al. [1] and Shera and Guinan [2] argues for two distinct mechanisms for the production of otoacoustic emissions: i) a retrograde traveling wave produced by the amplifier induced pressure gradient across the basilar membrane due primarily to the nonlinearities inherent in the amplifier, and ii) linear coherent reflections encompassing intracochlear standing waves. It would appear that for emissions arising from their characteristic frequency (CF) place, the dominant mechanism of production is one of reflection [2,3]. Inherent in a reflection mechanism is that the incident energy propagates to the CF place and then is reflected back to the stapes (i.e., two distinct delays, an anterograde delay and a retrograde delay). For emissions arising significantly basal to the CF place the dominant mechanism of production is non-linear, but it is not clear if such emissions are a result of reflection or energy injected into the basilar membrane by the active process. Estimates of delay to date have been largely based on phase-gradients of steady-state signals and not true time delays [4]. In this study, we report signal-front delays measured in the human from DPOAEs (2f1-f2) using a pulsed-tone paradigm. In particular, we examine whether all DPOAEs arise from reflection, albeit via different mechanisms.

  2. Flood characteristics of Alaskan streams

    USGS Publications Warehouse

    Lamke, R.D.

    1979-01-01

    Peak discharge data for Alaskan streams are summarized and analyzed. Multiple-regression equations relating peak discharge magnitude and frequency to climatic and physical characteristics of 260 gaged basins were determined in order to estimate average recurrence interval of floods at ungaged sites. These equations are for 1.25-, 2-, 5-, 10-, 25-, and 50-year average recurrence intervals. In this report, Alaska was divided into two regions, one having a maritime climate with fall and winter rains and floods, the other having spring and summer floods of a variety or combinations of causes. Average standard errors of the six multiple-regression equations for these two regions were 48 and 74 percent, respectively. Maximum recorded floods at more than 400 sites throughout Alaska are tabulated. Maps showing lines of equal intensity of the principal climatic variables found to be significant (mean annual precipitation and mean minimum January temperature), and location of the 260 sites used in the multiple-regression analyses are included. Little flood data have been collected in western and arctic Alaska, and the predictive equations are therefore less reliable for those areas. (Woodard-USGS)

  3. [Electroencephalographic characteristics of West syndrome].

    PubMed

    Kholin, A A; Mukhin, K Iu; Petrukhin, A S; Il'ina, E S

    2002-01-01

    The study aimed at interictal electroencephalographic characteristics investigation in the patients with West syndrome. It has been carried out in 48 children, aged 3 months--2 years, the inpatients of Psychoneurology and Epilepsy Department, Russian Clinical Children Hospital No. 2, from March 1999 to march 2001. The following EEG awakeness types were detected: typical hypsarrithmia--8 (16.7%) patients; different variants of modified hypsarrithmia--35 (72.9%); a presence of focal epileptiform discharges, but not in the form of modified hypsarrithmia with focal component--3 (6.2%); an absence of epileptiform discharges--2 (4.2%). Typical and modified hypsarrithmia cases ratio was estimated as 18.6%:81.4%. Among the patients with modified hypsarrithmia, the following variants have been detected: synchronized variant of modified hypsarrithmia--35.3% of the cases with modified hypsarrithmia; asymmetric regional or unilateral hypsarrithmia--42.9%; hypsarrithmia with partial component--45.7%; hypsarrithmia with persisting "suppressive-burst" pattern--20% of the cases. Correct evaluation of clinical, electrophysiological and neurovisual data (clinico-electro-anatomical approach) facilitated the rational differential choice of antiepileptic therapy. The approach allows the early prognosis of disease course and its transformation to other epilepsy types.

  4. X-33 Hypersonic Aerodynamic Characteristics

    NASA Technical Reports Server (NTRS)

    Murphy, Kelly J.; Nowak, Robert J.; Thompson, Richard A.; Hollis, Brian R.; Prabhu, Ramadas K.

    1999-01-01

    Lockheed Martin Skunk Works, under a cooperative agreement with NASA, will build and fly the X-33, a half-scale prototype of a rocket-based, single-stage-to-orbit (SSTO), reusable launch vehicle (RLV). A 0.007-scale model of the X-33 604B0002G configuration was tested in four hypersonic facilities at the NASA Langley Research Center to examine vehicle stability and control characteristics and to populate an aerodynamic flight database in the hypersonic regime. The vehicle was found to be longitudinally controllable with less than half of the total body flap deflection capability across the angle of attack range at both Mach 6 and Mach 10. At these Mach numbers, the vehicle also was shown to be longitudinally stable or neutrally stable for typical (greater than 20 degrees) hypersonic flight attitudes. This configuration was directionally unstable and the use of reaction control jets (RCS) will be necessary to control the vehicle at high angles of attack in the hypersonic flight regime. Mach number and real gas effects on longitudinal aerodynamics were shown to be small relative to X-33 control authority.

  5. X-33 Hypersonic Aerodynamic Characteristics

    NASA Technical Reports Server (NTRS)

    Murphy, Kelly J.; Nowak, Robert J.; Thompson, Richard A.; Hollis, Brian R.; Prabhu, Ramadas K.

    1999-01-01

    Lockheed Martin Skunk Works, under a cooperative agreement with NASA, will build and fly the X-33, a half-scale prototype of a rocket-based, single-stage-to-orbit (SSTO), reusable launch vehicle (RLV). A 0.007-scale model of the X-33 604B0002G configuration was tested in four hypersonic facilities at the NASA Langley Research Center to examine vehicle stability and control characteristics and to populate an aerodynamic flight database in the hypersonic regime, The vehicle was found to be longitudinally controllable with less than half of the total body flap deflection capability across the angle of attack range at both Mach 6 and Mach 10. At these Mach numbers, the vehicle also was shown to be longitudinally stable or neutrally stable for typical (greater than 20 degrees) hypersonic flight attitudes. This configuration was directionally unstable and the use of reaction control jets (RCS) will be necessary to control the vehicle at high angles of attack in the hypersonic flight regime. Mach number and real gas effects on longitudinal aerodynamics were shown to be small relative to X-33 control authority.

  6. Cervical characteristics of Noonan syndrome.

    PubMed

    Miyamoto, Jun J; Yabunaka, Tomoe; Moriyama, Keiji

    2014-04-01

    BACKGROUND/OBJECTIVES A short neck and low posterior hairline are characteristics of Noonan syndrome (NS) and are hallmarks of basilar invagination/impression. However, it is seldom that NS has been directly linked with this symptom. Thus, this study aimed to investigate basilar impression in NS subjects compared with control subjects and individuals exhibiting Turner Syndrome (TS). SUBJECTS/METHODS The degree of basilar impression and vertical positional differences of the third and fourth cervical vertebrae and hyoid bone in NS (n = 9, mean age: 12.1 years), TS (n = 9, mean age: 12.1 years), and control subjects (n = 9, mean age: 12.0 years) were investigated using lateral cephalometric radiographs. Differences between the three groups were compared using the Steel-Dwass test. Vertical positional differences in the anatomical structures within each group were compared using the Wilcoxon signed-rank test accompanied by a Bonferroni-Holm correction. RESULTS The distance by which the odontoid tip extended past McGregor's line in subjects with NS was significantly greater compared with TS and control subjects. The third and fourth cervical vertebrae were positioned significantly superiorly in subjects with NS compared with TS and control subjects and, in NS, were also significantly superior to the hyoid bone. There was no difference in the position of the hyoid bone itself between the groups. CONCLUSION/IMPLICATION These results suggest that basilar impression may be a frequently found symptom of NS.

  7. Examining distributional characteristics of clusters.

    PubMed

    von Eye, A

    2010-01-01

    Standard cluster analysis creates clusters based on the criterion that their members be closer to each other than to members of other clusters. In this article, it is proposed to examine empirical clusters that result from standard clustering, with the goal of assessing whether they contradict distributional assumptions. Four models are proposed. The models consider two data generation processes, the Poisson and the multinormal, as well as two convex shapes of cluster hulls, the spherical and the ellipsoidal. Based on the model, the probability of being in a cluster of a given location, size, and shape is estimated. This probability is compared with the observed proportion of cases. The observed proportion can turn out to be larger, as large, or smaller than expected. Examples are given using simulated and empirical data. The simulation showed that the size of a cluster, the data generation process, and the true distribution of data have the strongest effect on the results obtained with the proposed method. The empirical examples discuss distributional characteristics of cross-sectional and longitudinal clusters of aggressive behavior in adolescents. The examples show that clustering methods do not always yield clusters that contradict distributional assumptions. Some clusters contain even fewer cases than expected.

  8. X-33 Hypersonic Aerodynamic Characteristics

    NASA Technical Reports Server (NTRS)

    Murphy, Kelly J.; Nowak, Robert J.; Thompson, Richard A.; Hollis, Brian R.; Prabhu, Ramadas K.

    1999-01-01

    Lockheed Martin Skunk Works, under a cooperative agreement with NASA, will design, build, and fly the X-33, a half-scale prototype of a rocket-based, single-stage-to-orbit (SSTO), reusable launch vehicle (RLV). A 0.007-scale model of the X-33 604BOO02G configuration was tested in four hypersonic facilities at the NASA Langley Research Center to examine vehicle stability and control characteristics and to populate the aerodynamic flight database for the hypersonic regime. The vehicle was found to be longitudinally controllable with less than half of the total body flap deflection capability across the angle of attack range at both Mach 6 and Mach 10. Al these Mach numbers, the vehicle also was shown to be longitudinally stable or neutrally stable for typical (greater than 20 degrees) hypersonic flight attitudes. This configuration was directionally unstable and the use of reaction control jets (RCS) will be necessary to control the vehicle at high angles of attack in the hypersonic flight regime. Mach number and real gas effects on longitudinal aerodynamics were shown to be small relative to X-33 control authority.

  9. Photometric Characteristics of Lunar Terrains

    NASA Astrophysics Data System (ADS)

    Sato, Hiroyuki; Hapke, Bruce W.; Denevi, Brett W.; Robinson, Mark

    2016-10-01

    The photometric properties of the lunar depend on albedo, surface roughness, porosity, and the internal/external structure of particles. Hapke parameter maps derived using a bidirectional reflectance model [Hapke, 2012] from Lunar Reconnaissance Orbiter Camera (LROC) Wide Angle Camera (WAC) images demonstrated the spatial and spectral variation of the photometric properties of the Moon [Sato et al., 2014]. Using the same methodology, here we present the photometric characteristics of typical lunar terrains, which were not systematically analyzed in the previous study.We selected five representative terrain types: mare, highland, swirls, and two Copernican (fresh) crater ejecta (one mare and one highlands example). As for the datasets, we used ~39 months of WAC repeated observations, and for each image pixel, we computed latitude, longitude, incidence, emission, and phase angles using the WAC GLD100 stereo DTM [Scholten et al., 2012]. To obtain similar phase and incidence angle ranges, all sampling sites are near the equator and in the vicinity of Reiner Gamma. Three free Hapke parameters (single scattering albedo: w, HG2 phase function parameter: c, and angular width of SHOE: hs) were then calculated for the seven bands (321-689 nm). The remaining parameters were fixed by simplifying the model [Sato et al., 2014].The highlands, highland ejecta, and swirl (Reiner Gamma) showed clearly higher w than the mare and mare ejecta. The derived c values were lower (less backscattering) for the swirl and higher (more backscattering) for the highlands (and ejecta) relative to the other sites. Forward scattering materials such as unconsolidated transparent crystalline materials might be relatively enriched in the swirl. In the highlands, anorthositic agglutinates with dense internal scattering could be responsible for the strong backscattering. The mare and mare ejecta showed continuously decreasing c from UV to visible wavelengths. This might be caused by the FeO-rich pyroxene

  10. Key characteristics of specular stereo

    PubMed Central

    Muryy, Alexander A.; Fleming, Roland W.; Welchman, Andrew E.

    2014-01-01

    Because specular reflection is view-dependent, shiny surfaces behave radically differently from matte, textured surfaces when viewed with two eyes. As a result, specular reflections pose substantial problems for binocular stereopsis. Here we use a combination of computer graphics and geometrical analysis to characterize the key respects in which specular stereo differs from standard stereo, to identify how and why the human visual system fails to reconstruct depths correctly from specular reflections. We describe rendering of stereoscopic images of specular surfaces in which the disparity information can be varied parametrically and independently of monocular appearance. Using the generated surfaces and images, we explain how stereo correspondence can be established with known and unknown surface geometry. We show that even with known geometry, stereo matching for specular surfaces is nontrivial because points in one eye may have zero, one, or multiple matches in the other eye. Matching features typically yield skew (nonintersecting) rays, leading to substantial ortho-epipolar components to the disparities, which makes deriving depth values from matches nontrivial. We suggest that the human visual system may base its depth estimates solely on the epipolar components of disparities while treating the ortho-epipolar components as a measure of the underlying reliability of the disparity signals. Reconstructing virtual surfaces according to these principles reveals that they are piece-wise smooth with very large discontinuities close to inflection points on the physical surface. Together, these distinctive characteristics lead to cues that the visual system could use to diagnose specular reflections from binocular information. PMID:25540263

  11. Rainfall characteristics along mountainous transect

    NASA Astrophysics Data System (ADS)

    Zwiebel, Jimmy; Van Baelen, Joël; Anquetin, Sandrine; Pointin, Yves; Boudevillain, Brice

    2014-05-01

    The HYdrological cycle in Mediterranean EXperiment is an experiment framework that aims at improving our understanding and quantification of processes related to the hydrological cycle in the Mediterranean region at different scales (from the individual event scale to seasonal and inter-annual variability). During the Special Observation Period (SOP-1) conducted from September 5th to November 6th 2012, an important and complementary remote sensing network (operational radars, X band research radars, Micro Rain Radars, disdrometers, and a dense network of rain gauges) has been deployed in the Cévennes-Vivarais region (South of France). This network was specifically designed to investigate the structure and the heterogeneity of precipitations as well as, in particular, the impact of orography on this structure and it has provided us with high resolution data (time and space) along strong topographic gradients (small hills, foothills and mountain). Hence, these data will support our research to precisely describe the precipitation systems and their structures over a complex terrain. In this work, we will describe the characteristics of rainfall along two topographic gradients based on the major events observed during the fall 2012 campaign period. A classification according to the type of precipitation (convective, stratiform and orographic) which can affect the region has been made to investigate orographic impact under different rainfall regimes. We will also examine the influence of the relief on the vertical and horizontal structure of precipitation. In particular, we will illustrate the modification of the drop size distribution toward smaller droplets as we go from the small hills to the mountains.

  12. Indiana stream-temperature characteristics

    USGS Publications Warehouse

    Shampine, W.J.

    1977-01-01

    Periodic stream-temperature data have been collected at 280 different sites in Indiana by the U.S. Geological Survey and the Indiana State Board of Health. These data have been analyzed using a simple-harmonic curve-fitting procedure. When the equation coefficients are known, calculations can be made for a given stream to estimate the maximum and minimum temperatures, the temperature on a given day, the day a given temperature is expected, or the length of time temperatures will exceed, or be less than, a specific. The calculated harmonic coefficients were related to 23 topographic, basin, and climatic characteristics, and were analyzed by multiple-regression analysis techniques. The regional regression analysis for the harmonic- mean stream temperature, M, resulted in the following arithmetic function of station latitude (LAT). M = 41.36 - 0.7166 (LAT) The multiple correlation coefficient (r) was .72. Poor correlations were found for the harmonic phase-angle and amplitude coefficients, C and A, respectively. Constants of 4.32 radians for C and 11.27° Celsius for A are suggested as average statewide values in Indiana streams. The mean temperature of the White River at Indianapolis was raised 3.5° Celsius above expected ambient levels caused by climatic conditions alone, primarily as a result of discharges from powerplants. In general, the harmonic coefficients depicting annual variability in stream temperatures, generated from the Indiana State board of Health data collected every 2 weeks, are the same as coefficients generated from the U.S. Geological Survey date collected every 4-6 weeks.

  13. Characteristics of active seawater intrusion

    NASA Astrophysics Data System (ADS)

    Badaruddin, Sugiarto; Werner, Adrian D.; Morgan, Leanne K.

    2017-08-01

    The inland migration of seawater in coastal aquifers, known as seawater intrusion (SWI), can be categorised as passive or active, depending on whether the hydraulic gradient slopes downwards towards the sea or the land, respectively. Despite active SWI occurring in many locations, it has received considerably less attention than passive SWI. In this study, active SWI caused by an inland freshwater head decline (FHD) is characterised using numerical modelling of various idealised unconfined coastal aquifer settings. Relationships between key features of active SWI (e.g., interface characteristics and SWI response time-scales) and the parameters of the problem (e.g., inland FHD, freshwater-seawater density contrast, dispersivity, hydraulic conductivity, porosity and aquifer thickness) are explored for the first time. Sensitivity analyses show that the SWI response time-scales under active SWI situations are influenced by both the initial and final boundary head differences. The interface is found to be steeper under stronger advection (i.e., caused by the inland FHD), higher dispersivity and hydraulic conductivity, and lower aquifer thickness, seawater density and porosity. The interface movement is faster and the mixing zone is wider with larger hydraulic conductivity, seawater-freshwater density difference, and aquifer thickness, and with lower porosity. Dimensionless parameters (Peclet number and mixed convection ratio) from previous steady-state analyses offer only limited application to the controlling factors of passive SWI, and are not applicable to active SWI. The current study of active SWI highlights important functional relationships that improve the general understanding of SWI, which has otherwise been founded primarily on steady-state and passive SWI.

  14. The Seismotectonic Characteristics of Slovenia

    NASA Astrophysics Data System (ADS)

    Poljak, M.; Živčić, M.; Zupančič, P.

    Slovenia with its neighbouring areas lies at the junction of the Alps, the Dinarides and the Pannonian basin. These belong to the three plates: Europe, Adria and Tisza. On the Slovenian territory itself converge the External Dinarides NW-SE oriented right lateral strike-slip faults, the Transdanubian Range NE-SW oriented left lateral strike-slip faults, and the Southern Alps E-W oriented thrusts. The direction of the principal stress σ1 (azimuth = 6°, dip = 8°) is determined under the assumption of uniform stress throughout the region. Dip of the least principal stress σ3 of 5° is consistent with the regional strike-slip regime. Listed structures form a pure shear structural mechanism on a regional scale.In spite of geologic evidence of tectonic displacements along mentioned structures in the past, there is no surface expression of their recent activity.The lithospheric units of the investigated area were amalgamated together during Tertiary. The seismicity is not concentrated along the primary plate boundaries but is rather spread in a broad zone along their deformed rims. The seismicity is moderate with the average depth of earthquakes in Slovenia of 6.5 km, and 9 to 20 km for stronger earthquakes (MLH > 4.2). No surface rupture related to an earthquake has been detected to date in Slovenia.The territory of Slovenia and its neighbouring regions has been delineated into five seismogenic areas, i.e., the areas with similar and among themselves differentiable tectonic and seismological characteristics. They are the Eastern Alps, the Southern Alps, with the Friuli region as a separate unit, the External Dinarides, and the Transdanubian Range.

  15. Key characteristics of specular stereo.

    PubMed

    Muryy, Alexander A; Fleming, Roland W; Welchman, Andrew E

    2014-12-24

    Because specular reflection is view-dependent, shiny surfaces behave radically differently from matte, textured surfaces when viewed with two eyes. As a result, specular reflections pose substantial problems for binocular stereopsis. Here we use a combination of computer graphics and geometrical analysis to characterize the key respects in which specular stereo differs from standard stereo, to identify how and why the human visual system fails to reconstruct depths correctly from specular reflections. We describe rendering of stereoscopic images of specular surfaces in which the disparity information can be varied parametrically and independently of monocular appearance. Using the generated surfaces and images, we explain how stereo correspondence can be established with known and unknown surface geometry. We show that even with known geometry, stereo matching for specular surfaces is nontrivial because points in one eye may have zero, one, or multiple matches in the other eye. Matching features typically yield skew (nonintersecting) rays, leading to substantial ortho-epipolar components to the disparities, which makes deriving depth values from matches nontrivial. We suggest that the human visual system may base its depth estimates solely on the epipolar components of disparities while treating the ortho-epipolar components as a measure of the underlying reliability of the disparity signals. Reconstructing virtual surfaces according to these principles reveals that they are piece-wise smooth with very large discontinuities close to inflection points on the physical surface. Together, these distinctive characteristics lead to cues that the visual system could use to diagnose specular reflections from binocular information. © 2014 ARVO.

  16. Electromagnetomechanical coupling characteristics of plastoferrites

    NASA Astrophysics Data System (ADS)

    Brosseau, Christian; NDong, Wilfried; Castel, Vincent; Youssef, Jamal Ben; Vidal, Alain

    2007-07-01

    The impetus of this work was to investigate the electromagnetic and tensile properties of several commercially available plastoferrites (PFs) at ambient conditions. The approach involved selection of a set of PFs and measuring their complex effective permittivity ɛ =ɛ'-jɛ″ and permeability μ =μ'-jμ″ under uniaxial stress at microwave frequencies (0.1-4.5GHz) and room temperature. We analyze the ɛ and μ spectra for tensilely strained PFs up to 3%. Comparing our experimental ɛ data against several dielectric relaxational behaviors, we find that the main physics cannot be understood with a single relaxation mechanism. We then go on to consider the magnetic permeability spectra in the microwave range of frequencies and show that an appropriate magnetization mechanism is given by the gyromagnetic spin resonance mechanism. We use a combination of Bruggeman mean field analysis and Landau-Lifshitz-Gilbert modeling to reproduce the experimental bimodal line-shape characteristics of the effective complex magnetic permeability. These findings are discussed in light of the polydispersity in size of the ferrite gains contained in the PFs. The vibrating sample magnetometry investigations of the static magnetization are found to be consistent with this modeling. In addition, the analysis shows also how magnetized PFs respond to electromagnetic waves, and we evaluate the hysteretic behaviors of ɛ and μ. More importantly we show that the ɛ and μ measurements under stress can be explained in terms of a Gaussian molecular network model in the limit of low stress. The present results have important applications in magnetoactive smart composite materials, e.g., flexible circuit technology in the electronics industry (sensors, actuators, and micromechanical systems), functionalized artificial skin, and muscles for robotic applications.

  17. The effect of ceramic/metal gradient armor's components characteristic on its impact-resistant characteristic

    SciTech Connect

    Liu Lisheng; Zhang Qingjie; Zhai Pengcheng; Cao Dongfeng

    2008-02-15

    The effect of ceramic/metal gradient armor's components characteristic on its impact-resistant characteristic has been investigated by a new modified Alekseevskii-Tate equation. The following researching work is done by the former model [1]: the effect of ceramic layer on the impact-resistant characteristic, the effect of gradient layer on the impact-resistant characteristic and the effect of metal layer on the impact-resistant characteristic.

  18. Effective characteristics of corrugated plates

    NASA Astrophysics Data System (ADS)

    Arkhangel'skii, A. F.; Gorbachev, V. I.

    2007-06-01

    characteristic dimension L. As a result, the dependence between the new local variables and the new scaled dimensionless variables is such that the factor 1/ α, where α= l/ L ≪ 1 is a small geometric parameter, appears in differentiating any function of the local coordinate with respect to the global coordinate. After this, the solution of the problem in new coordinates is sought as an asymptotic expansion in the small geometric parameter [1], [4-10]. We note that, in the small geometric parameter method, the asymptotic series simultaneously have the form of expansions in the gradients of functions depending only on the global coordinates. This averaging procedure can be applied to linear and nonlinear boundary value problems for differential equations with variable periodic coefficients for which the periodicity cell can be affinely transformed into the periodicity cube. In the case of an arbitrary dependence of the coefficients on the coordinates (including periodic dependence), another averaging technique can be used in linear problems. This technique is based on the possibility of the integral representation of the solution of the original problem for the linear equation with variables coefficients in terms of the solution of the same problem for an equation of the same type but with constant coefficients [11-13]. The integral representation implies that the solution of the original problem can be represented in the form of the series in the gradients of the solution of the problem for the equation with constant coefficients [13]. The aim of the present paper is to develop methods for calculating effective characteristics of corrugated plates. To this end, we first write out the equilibrium equations for a flexible anisotropic plate, which is inhomogeneous in the thickness direction and in the horizontal projection, with an initial deflection. We write these equations in matrix form, which allows one to significantly reduce the length of the expressions and to simplify

  19. Flood-frequency characteristics of Wisconsin streams

    USGS Publications Warehouse

    Walker, John F.; Krug, William R.

    2003-01-01

    Flood-frequency characteristics for 312 gaged sites on Wisconsin streams are presented for recurrence intervals of 2 to 100 years using flood-peak data collected through water year 2000. Equations of the relations between flood-frequency and drainage-basin characteristics were developed by multiple-regression analyses. Flood-frequency characteristics for ungaged sites on unregulated, rural streams can be estimated by use of these equations. The state was divided into five areas with similar physiographic characteristics. The most significant basin characteristics are drainage area, main-channel slope, soil permeability, storage, rainfall intensity, and forest cover. The standard error of prediction for the equation for the 100-year flood discharge ranges from 22 to 44 percent in the state. A graphical method for estimating flood-frequency characteristics of regulated streams was developed from the relation of discharge and drainage area. Graphs for the major regulated streams are presented.

  20. Characteristics of the equine embryo and fetus from days 15 to 107 of pregnancy.

    PubMed

    Franciolli, André Luis Rezende; Cordeiro, Bruna Mascaro; da Fonseca, Erika Toledo; Rodrigues, Marcio Nogueira; Sarmento, Carlos Alberto Palmeira; Ambrosio, Carlos Eduardo; de Carvalho, Ana Flavia; Miglino, Maria Angélica; Silva, Luciano Andrade

    2011-09-15

    In spite of numerous, substantial advances in equine reproduction, many stages of embryonic and fetal morphological development are poorly understood, with no apparent single source of comprehensive information. Hence, the objective of the present study was to provide a complete macroscopic and microscopic description of the equine embryo/fetus at various gestational ages. Thirty-four embryos/fetuses were aged based on their crown rump length (CRL), and submitted to macroscopic description, biometry, light and scanning microscopy, as well as the alizarin technique. All observed developmental changes were chronologically ordered and described. As examples of the main observed features, an accentuated cervical curvature was observed upon macroscopic examination in all specimens. In the nervous system, the encephalic fourth ventricle and the encephalic vesicles forebrain, midbrain, and hindbrain, were visualized from Day 19 (ovulation = Day 0). The thoracic and pelvic limbs were also visualized; their extremities gave rise to the hoof during development from Day 27. Development of other structures such as pigmented optical vesicle, liver, tail, cardiac area, lungs, and dermal vascularization started on Days 25, 25, 19, 19, 34, and 35, respectively. Light and scanning microscopy facilitated detailed examinations of several organs, e.g., heart, kidneys, lungs, and intestine, whereas the alizarin technique enabled visualization of ossification. Observations in this study contributed to the knowledge regarding equine embryogenesis, and included much detailed data from many specimens collected over a long developmental interval.

  1. Thermo-optical characteristics of DKDP crystal

    NASA Astrophysics Data System (ADS)

    Mironov, E. A.; Vyatkin, A. G.; Starobor, A. V.; Palashov, O. V.

    2017-03-01

    This letter presents a theoretical and experimental investigation of thermally induced polarization distortions occurring in an optical element made of c-cut tetragonal crystals. Two material characteristics were defined for this class of crystals: the optical anisotropy parameter ξ and the thermo-optical constant Q. These were generalized with analogous characteristics of elastically isotropic cubic crystals. The experimental investigation of these characteristics for popular tetragonal deuterated potassium dihydrogen phosphate (DKDP) crystal was carried out.

  2. Quasilinear systems with linearizable characteristic webs

    NASA Astrophysics Data System (ADS)

    Agafonov, S. I.; Ferapontov, E. V.; Novikov, V. S.

    2017-07-01

    We classify quasilinear systems in Riemann invariants whose characteristic webs are linearizable on every solution. Although the linearizability of an individual web is a rather nontrivial differential constraint, the requirement of linearizability of characteristic webs on all solutions imposes simple second-order constraints for the characteristic speeds of the system. It is demonstrated that every such system with n >3 components can be transformed by a reciprocal transformation to n uncoupled Hopf equations. All our considerations are local.

  3. Audiometric Characteristics of Hyperacusis Patients

    PubMed Central

    Sheldrake, Jacqueline; Diehl, Peter U.; Schaette, Roland

    2015-01-01

    Hyperacusis is a frequent auditory disorder where sounds of normal volume are perceived as too loud or even painfully loud. There is a high degree of co-morbidity between hyperacusis and tinnitus, most hyperacusis patients also have tinnitus, but only about 30–40% of tinnitus patients also show symptoms of hyperacusis. In order to elucidate the mechanisms of hyperacusis, detailed measurements of loudness discomfort levels (LDLs) across the hearing range would be desirable. However, previous studies have only reported LDLs for a restricted frequency range, e.g., from 0.5 to 4 kHz or from 1 to 8 kHz. We have measured audiograms and LDLs in 381 patients with a primary complaint of hyperacusis for the full standard audiometric frequency range from 0.125 to 8 kHz. On average, patients had mild high-frequency hearing loss, but more than a third of the tested ears had normal hearing thresholds (HTs), i.e., ≤20 dB HL. LDLs were found to be significantly decreased compared to a normal-hearing reference group, with average values around 85 dB HL across the frequency range. However, receiver operating characteristic analysis showed that LDL measurements are neither sensitive nor specific enough to serve as a single test for hyperacusis. There was a moderate positive correlation between HTs and LDLs (r = 0.36), i.e., LDLs tended to be higher at frequencies where hearing loss was present, suggesting that hyperacusis is unlikely to be caused by HT increase, in contrast to tinnitus for which hearing loss is a main trigger. Moreover, our finding that LDLs are decreased across the full range of audiometric frequencies, regardless of the pattern or degree of hearing loss, indicates that hyperacusis might be due to a generalized increase in auditory gain. Tinnitus on the other hand is thought to be caused by neuroplastic changes in a restricted frequency range, suggesting that tinnitus and hyperacusis might not share a common mechanism. PMID:26029161

  4. Biometry of the anterior border of the human hip bone: normal values and their use in sex determination.

    PubMed Central

    Gómez Pellico, L; Fernández Camacho, F J

    1992-01-01

    Sixteen different variables and 3 indices for the anterior border of 42 human hip bones from a Spanish skeletal collection were studied. Values for 15 of these variables and for the 3 indices are reported. We were unable to detect statistically significant differences between means relating to side in any of the variables and indices studied. Statistically significant differences were detected between means in relation to sex for 4 variables (distance from the anterior superior iliac spine to the pubic tubercle, distance from the anterior inferior iliac spine to the iliopubic eminence, distance from the anterior inferior iliac spine to the pubic tubercle, length of the notch between the anterior inferior iliac spine and the iliopubic eminence). These variables could be used for sex determination from the human hip bone or its fragments. PMID:1304579

  5. LBA-ECO TG-07 Ground-based Biometry Data at km 83 Site, TapajosNational Forest: 1997

    Treesearch

    M.M. Keller; M.W. Palace

    2009-01-01

    A field inventory of trees was conducted in March of 1997 in a logging concession at the Tapajos National Forest, south of Santarem, Para, Brazil. The inventory was conducted by the foresters and technicians of the Tropical Forest Foundation (FFT) and included all trees with diameter at breast height greater than or equal to 35 cm. Four blocks of approximately 100 ha...

  6. Imaging and full-length biometry of the eye during accommodation using spectral domain OCT with an optical switch

    PubMed Central

    Ruggeri, Marco; Uhlhorn, Stephen R.; De Freitas, Carolina; Ho, Arthur; Manns, Fabrice; Parel, Jean-Marie

    2012-01-01

    Abstract: An optical switch was implemented in the reference arm of an extended depth SD-OCT system to sequentially acquire OCT images at different depths into the eye ranging from the cornea to the retina. A custom-made accommodation module was coupled with the delivery of the OCT system to provide controlled step stimuli of accommodation and disaccommodation that preserve ocular alignment. The changes in the lens shape were imaged and ocular distances were dynamically measured during accommodation and disaccommodation. The system is capable of dynamic in vivo imaging of the entire anterior segment and eye-length measurement during accommodation in real-time. PMID:22808424

  7. Nickel-hydrogen cell reversal characteristics

    NASA Technical Reports Server (NTRS)

    Lurie, Charles

    1994-01-01

    Nickel-hydrogen cell reversal characteristics are being studied as part of a TRW program directed towards development of a high current battery cell bypass switch. The following are discussed: cell bypass switch; nickel-hydrogen cell reversal characteristics; and nickel-hydrogen cell chemistry: discharge/reversal and overdischarge (reversal) with nickel and hydrogen precharge.

  8. 33 CFR 62.45 - Light characteristics.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Light characteristics. 62.45... NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.45 Light characteristics. (a) Lights on aids to navigation are differentiated by color and rhythm. Lighthouses and...

  9. 33 CFR 62.45 - Light characteristics.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Light characteristics. 62.45... NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.45 Light characteristics. (a) Lights on aids to navigation are differentiated by color and rhythm. Lighthouses and...

  10. 33 CFR 62.45 - Light characteristics.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Light characteristics. 62.45... NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.45 Light characteristics. (a) Lights on aids to navigation are differentiated by color and rhythm. Lighthouses and...

  11. 33 CFR 62.45 - Light characteristics.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Light characteristics. 62.45... NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.45 Light characteristics. (a) Lights on aids to navigation are differentiated by color and rhythm. Lighthouses and...

  12. 33 CFR 62.45 - Light characteristics.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Light characteristics. 62.45... NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.45 Light characteristics. (a) Lights on aids to navigation are differentiated by color and rhythm. Lighthouses and...

  13. Selective Recruiting: College Characteristics and Job Outcomes.

    ERIC Educational Resources Information Center

    Colarelli, Stephen M.; And Others

    Although institutions of higher education differ widely, little is known about the effects of different college characteristics on early career outcomes. A study was conducted to examine the relationships among nine college characteristics and job offers, employment status, job attitudes, and job performance of recent college graduates. College…

  14. 10 CFR 61.56 - Waste characteristics.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Waste characteristics. 61.56 Section 61.56 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR LAND DISPOSAL OF RADIOACTIVE WASTE Technical Requirements for Land Disposal Facilities § 61.56 Waste characteristics. (a) The following requirements...

  15. 10 CFR 61.56 - Waste characteristics.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Waste characteristics. 61.56 Section 61.56 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR LAND DISPOSAL OF RADIOACTIVE WASTE Technical Requirements for Land Disposal Facilities § 61.56 Waste characteristics. (a) The following requirements...

  16. 10 CFR 61.56 - Waste characteristics.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Waste characteristics. 61.56 Section 61.56 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR LAND DISPOSAL OF RADIOACTIVE WASTE Technical Requirements for Land Disposal Facilities § 61.56 Waste characteristics. (a) The following requirements...

  17. 30 CFR 7.99 - Critical characteristics.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) Diesel engine approval marking. (g) Fuel rate setting to ensure that it is appropriate for the intended... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Diesel Power Packages Intended for Use in... characteristics. The following critical characteristics shall be inspected or tested on each diesel power...

  18. 30 CFR 7.99 - Critical characteristics.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) Diesel engine approval marking. (g) Fuel rate setting to ensure that it is appropriate for the intended... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Diesel Power Packages Intended for Use in... characteristics. The following critical characteristics shall be inspected or tested on each diesel power...

  19. 30 CFR 7.45 - Critical characteristics

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... APPROVAL OF MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Battery Assemblies § 7.45 Critical characteristics The following critical characteristics shall be inspected or tested on each battery assembly to... of insulating material. (c) Size and location of ventilation openings. (d) Method of...

  20. Vowel Space Characteristics and Vowel Identification Accuracy

    ERIC Educational Resources Information Center

    Neel, Amy T.

    2008-01-01

    Purpose: To examine the relation between vowel production characteristics and intelligibility. Method: Acoustic characteristics of 10 vowels produced by 45 men and 48 women from the J. M. Hillenbrand, L. A. Getty, M. J. Clark, and K. Wheeler (1995) study were examined and compared with identification accuracy. Global (mean f0, F1, and F2;…

  1. Vowel Space Characteristics and Vowel Identification Accuracy

    ERIC Educational Resources Information Center

    Neel, Amy T.

    2008-01-01

    Purpose: To examine the relation between vowel production characteristics and intelligibility. Method: Acoustic characteristics of 10 vowels produced by 45 men and 48 women from the J. M. Hillenbrand, L. A. Getty, M. J. Clark, and K. Wheeler (1995) study were examined and compared with identification accuracy. Global (mean f0, F1, and F2;…

  2. Prospective Teachers' Personal Characteristics to Multicultural Education

    ERIC Educational Resources Information Center

    Eskici, Menekse

    2016-01-01

    The aim of this paper is to determine prospective teachers' personal characteristics to multicultural education. It is also aimed to reveal whether there are meaningful differences in prospective teachers' personal characteristics to multicultural education according to their genders, age and number of siblings. The descriptive model was chosen to…

  3. Potato Types and Characteristics: Laboratory Exercises.

    ERIC Educational Resources Information Center

    Pavlista, Alexander D.

    1997-01-01

    Presents a number of simple exercises that demonstrate potato tuber characteristics and are designed for high school biology students and teachers. Exercises include Typing, Grading, Shape, Eye Characteristics, Defects, Specific Gravity, Dry Matter Content, Glucose Content, Baking, Frying/Chipping, and Taste Testing. (JRH)

  4. Some Structural Characteristics of Music Television Videos.

    ERIC Educational Resources Information Center

    Fry, Donald L.; Fry, Virginia H.

    1987-01-01

    Indicates, by analyzing two types of montage structures, that music television is a hybrid form of television programing displaying visual characteristics of both television commercials and drama. Argues that this amalgam of different characteristics gives music television its distinctive look and power as a promotional tool for the record…

  5. Structural and Environmental Characteristics of Stereotyped Behaviors.

    ERIC Educational Resources Information Center

    Hall, Scott; Thorns, Tracy; Oliver, Chris

    2003-01-01

    This study examined structural characteristics and environmental variables in the stereotypic behaviors of eight individuals with developmental disabilities. Findings indicated that structural characteristics (percentage of time, bout length, and bout length variability) were highly correlated. Also, stereotyped behaviors were more likely to occur…

  6. Leader Behavior Characteristics and Organizational Climate.

    ERIC Educational Resources Information Center

    Wiggins, Thomas W.

    To investigate the leader behavior characteristics of elementary school principals and to examine these characteristics as they relate to organizational climate, 35 randomly selected southern California schools with approximately 715 teachers and principals were studied. The data on organizational climate were collected by means of the…

  7. 46 CFR 109.564 - Maneuvering characteristics.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Maneuvering characteristics. 109.564 Section 109.564 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.564 Maneuvering characteristics. (a) The master or person in charge of each...

  8. 46 CFR 109.564 - Maneuvering characteristics.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Maneuvering characteristics. 109.564 Section 109.564 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.564 Maneuvering characteristics. (a) The master or person in charge of each...

  9. 46 CFR 109.564 - Maneuvering characteristics.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Maneuvering characteristics. 109.564 Section 109.564 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.564 Maneuvering characteristics. (a) The master or person in charge of each...

  10. 46 CFR 109.564 - Maneuvering characteristics.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Maneuvering characteristics. 109.564 Section 109.564 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.564 Maneuvering characteristics. (a) The master or person in charge of each...

  11. Personality Characteristics of Adult Children of Alcoholics.

    ERIC Educational Resources Information Center

    Seefeldt, Richard W.; Lyon, Mark A.

    1992-01-01

    Conducted study to validate characteristics of Adult Children of Alcoholics (ACOAs) as presented by Woititz (1983). Findings from college students self-reported to be ACOAs, non-ACOAs, or individuals who had participated in ACOA treatment group were compared on 12 of Woititz's 13 characteristics using objective personality measures. No significant…

  12. 30 CFR 7.405 - Critical characteristics.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Critical characteristics. 7.405 Section 7.405 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND... Cable Splice Kits § 7.405 Critical characteristics. (a) A sample from each production run, batch, or...

  13. Charts for interpreting wildland fire behavior characteristics

    Treesearch

    Patricia L. Andrews; Richard C. Rothermel

    1982-01-01

    The fire characteristics chart is proposed as a graphical method ofpresenting two primary characteristics of fire behavior – spread rate and intensity. Its primary use is communicating and interpreting either site-specific predictions of fire behavior or National Fire-Danger Rating System (NFDRS) indexes and components. Rate of spread, heat per unit area, flame length...

  14. Methods for Predicting Submersible Hydrodynamic Characteristics

    DTIC Science & Technology

    1978-07-01

    TO PREDICT COMPLETE CONFIGURATION CHARACTERISTICS In this section the previously developed methods are combined to determine... characteristics of individual vehicle components (bodies, tails ), and with their mutual interactions when combined into complete configurations . Each method is...approach used successfully in mis- sile aerodynamics , a set of models was built and tested to obtain systematic data over relevant ranges of geometry

  15. Developmental Characteristics of Nontraditional Aged Students.

    ERIC Educational Resources Information Center

    Butler, Edward R.; Markley, Howard D.

    This research examined Chickering's psychosocial developmental characteristics of nontraditional aged (25-45) university freshmen and compared these developmental characteristics with those reported for traditional aged (18-24) freshmen to determine if significant differences exist between these groups of students. The Student Developmental Task…

  16. Sport Management Graduate Programs: Characteristics of Effectiveness.

    ERIC Educational Resources Information Center

    Li, Ming; And Others

    1994-01-01

    Reports a study that examined the characteristics that enable graduate sport management programs to achieve their objectives. Surveys of sport management educators found they agreed on 11 characteristics that indicated a sport management program's effectiveness. Respondents believed an effective program should produce sport managers, not…

  17. 10 CFR 61.56 - Waste characteristics.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Waste characteristics. 61.56 Section 61.56 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR LAND DISPOSAL OF RADIOACTIVE WASTE Technical Requirements for Land Disposal Facilities § 61.56 Waste characteristics. (a) The following requirements are...

  18. Some engineering characteristics of heavyweight shotcrete

    NASA Astrophysics Data System (ADS)

    Cakıroglu, M. Alkan; Akkas, A.

    2015-03-01

    In this study some engineering characteristics of heavyweight shotcrete were determined that encountered any information in the literature, for this purpose heavyweight shotcrete were produced with using barite aggregates, that max grain size was 8mm, and some engineering characteristics such as compressive strength, Elastic Modules and ultrasonic pulse velocity were investigated with nondestructive tests.

  19. Characteristics Orientation, Needs and Expectations. Symposium.

    ERIC Educational Resources Information Center

    2002

    This document contains three papers from a symposium on characteristics orientation, needs, and expectations. "Characteristics Orientation of Emerging Professions: Implications for Research, Policy, and Practice of Continuing Professional Education" (William H. Young, Margot B. Weinstein) reports on a qualitative study that examined…

  20. Potato Types and Characteristics: Laboratory Exercises.

    ERIC Educational Resources Information Center

    Pavlista, Alexander D.

    1997-01-01

    Presents a number of simple exercises that demonstrate potato tuber characteristics and are designed for high school biology students and teachers. Exercises include Typing, Grading, Shape, Eye Characteristics, Defects, Specific Gravity, Dry Matter Content, Glucose Content, Baking, Frying/Chipping, and Taste Testing. (JRH)

  1. 40 CFR 261.24 - Toxicity characteristic.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... characteristic of toxicity if, using the Toxicity Characteristic Leaching Procedure, test Method 1311 in “Test...-49-2 1.0 D011 Silver 7440-22-4 5.0 D039 Tetrachloroethyl-ene 127-18-4 0.7 D015 Toxaphene 8001-35-2...

  2. [Characteristics and mechanism of boat propeller injuries].

    PubMed

    Yu, Song; Shen, Yi-Wen; Xue, Ai-Min

    2008-02-01

    To summarize the characteristics and investigate the mechanisms of boat propeller injuries so as to explore the identification methods between boat propeller injuries and corpse dismemberment. More than 100 autopsy cases of boat propeller injuries were collected in a period between 1994 and 2005 in Huzhou district, Zhejiang province. The characteristics of injuries caused by propeller, including abrasion, wound, fracture and severed wound, and the characteristics of clothing, were retrospectively studied and summarized. The severed cross wound section of boat propeller injuries was compared with that caused by corpse dismemberment. The boat propeller injuries were resulted from high-speed propellers with enormous splitting power and mechanical cutting, while corpse dismemberment were resulted from cutting and dismembering the body with sharp instruments. Due to the different mechanisms, the different strength of force and recoil force, the severed wound cross section had different characteristics. Wounds caused by boat propeller injuries have their unique characteristics, distinguished from wounds of dismembered corpse.

  3. Transmission Characteristics Simulation on Power Line Communications

    NASA Astrophysics Data System (ADS)

    Kitayama, Masashi; Nakabayashi, Miyuki; Abe, Junichi; Tanabe, Shinji

    In Power Line Communication (PLC) systems, medium and low voltage power distribution lines are used as a communication network. However, since no consideration is given to signal transmission characteristics in the high frequency used for PLC systems, reflections caused by impedance mismatches deteriorate transmission characteristics. If channel characteristics of power lines can be estimated by simulation, it will be efficient for the design and the operation of PLC networks. This paper proposes a method to estimate transmission characteristics of a channel model between a transmitter and a receiver installed on a distribution network. Propagation characteristics of PLC signals at each distribution facility is described using two port networks. A channel model is automatically generated from the combination of component models along the topology of distribution network and the locations of a transmitter and a receiver. The proposed method was validated using measurement data of a test distribution network and was proved to be effective.

  4. Quantifying physical characteristics of wildland fuels using the fuel characteristic classification system.

    Treesearch

    Cynthia L. Riccardi; Susan J. Prichard; David V. Sandberg; Roger D. Ottmar

    2007-01-01

    Wildland fuel characteristics are used in many applications of operational fire predictions and to understand fire effects and behaviour. Even so, there is a shortage of information on basic fuel properties and the physical characteristics of wildland fuels. The Fuel Characteristic Classification System (FCCS) builds and catalogues fuelbed descriptions based on...

  5. Information retrieval: an overview of system characteristics.

    PubMed

    Wiesman, F; Hasman, A; van den Herik, H J

    1997-11-01

    The paper gives an overview of characteristics of information retrieval (IR) systems. The characteristics are identified from the descriptions of 23 IR systems. Four IR models are discussed: the Boolean model, the vector model, the probabilistic model and the connectionistic model. Twelve other characteristics of IR models are identified: search intermediary, domain knowledge, relevance feedback, natural language interface, graphical query language, conceptual queries, full-text IR, field searching, fuzzy queries, hypertext integration, machine learning, and ranked output. Finally, the relevance of IR systems for the World Wide Web is established.

  6. Output tube emission characteristics of operational radars

    NASA Astrophysics Data System (ADS)

    Matheson, R. J.; Smilley, J. D.; Falcon, G. D.; Lawrence, V. S.

    1982-01-01

    Measurement of the emission spectra and other characteristics of many radars operating in the government frequency bands is described. The emission spectra of 19 different types of radars, selected to show the different emission spectrum characteristics produced by a variety of radar output tube technologies are presented. The radars include examples of ground based search, airport surveillance, weather, and height finding radars operating in L band, S band, or C band. The RSMS, contained within a mobile van, is described, along with the measurement techniques used for obtaining radar emission characteristics. The emission limits imposed by the Radar Spectrum Engineering Criteria (RSEC) are displayed with each emission spectrum.

  7. Variable nonlinear transfer characteristics of MSLM

    NASA Astrophysics Data System (ADS)

    Kobayashi, Yuji; Hara, Tsutomu; Suzuki, Yoshiji

    1990-08-01

    Variable nonlinear transfer characteristics (gamma characteristics) of microchannel spatial light modulator (MSLM) are investigated theoretically and experimentally. The MSLM structure and the principle of operation are discussed, and experimental results are presented. It is shown that the thresholding nonlinearities of the MSLM can be controlled by either the mesh voltage or by writing the time change in the thresholding operation. The resulting variable nonlinear transfer characteristics can be used in various optical processings such as a sigmoid function on optical neural networks and an analog operating on optical information processing.

  8. Enhanced flight characteristics by heterogeneous autorotating wings

    NASA Astrophysics Data System (ADS)

    Vincent, Lionel; Zheng, Min; Kanso, Eva

    2015-11-01

    We investigate experimentally the effect of mass distribution and flexibility on the descent motion of thin rectangular auto-rotating wings. We vary the wing thickness and material density under carefully controlled initial conditions. We focus in particular on the flight characteristics and how it affects the dispersion properties, namely, the flight duration, descent angle, and flight range. We found that altering the mass distribution along the auto-rotation axis generally leads to a diminution of aerodynamic characteristics, in agreement with previous studies. On the other hand, changing the mass distribution width-wise can lead to enhanced flight characteristics, from beneficial aerodynamic effects.

  9. Arsenic Treatment Residuals: Quantities, Characteristics and Disposal

    EPA Science Inventory

    This presentation provides information on the quantities, the characteristics and the disposal options for the common arsenic removal technologies. The technologies consist of adsorption media, iron removal, coagulation/filtration and ion exchange. The information for the prese...

  10. Learner Characteristics, Learning Environments and Constructivist Epistemologies.

    ERIC Educational Resources Information Center

    Simpson, Gary

    2001-01-01

    Focuses on a current research project that examines the measurement of learner characteristics (multiple intelligence, learning style, learner ability), learner perceptions of the classroom (constructivist learning environment survey and views about teaching and learning), and learner constructs. (Author/MM)

  11. 49 CFR 236.717 - Characteristics, operating.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.717 Characteristics, operating. The measure of electrical values at which electrical or...

  12. Fact-File: Freshman Characteristics and Attitudes.

    ERIC Educational Resources Information Center

    Chronicle of Higher Education, 1985

    1985-01-01

    A national profile based on responses of 182,000 students who entered college in the fall of 1984 is presented. Characteristics and attitudes covered include: age, racial/ethnic background, parental occupation, activities, political views, etc. (MLW)

  13. Imaginary Play Companions: Characteristics and Functions.

    ERIC Educational Resources Information Center

    Kalyan-Masih, V.

    1986-01-01

    Investigates some of the following characteristics associated with young children playing with imaginary play companions (IPCs): intelligence, parental and socioeconomic and educational background, family size, and birth order. Compares these children to those without IPCs. (HOD)

  14. Arsenic Treatment Residuals: Quantities, Characteristics and Disposal

    EPA Science Inventory

    This presentation provides information on the quantities, the characteristics and the disposal options for the common arsenic removal technologies. The technologies consist of adsorption media, iron removal, coagulation/filtration and ion exchange. The information for the prese...

  15. Electromagnetic wave propagation characteristics in unimolecular reactions

    NASA Astrophysics Data System (ADS)

    Liu, Xingpeng; Huang, Kama

    2016-01-01

    Microwave-assisted chemical reactions have attracted interests because of their benefits for enhancement of reaction rates. However, the problems, such as hot spots and thermal runaway, limit the application of microwaves in the chemical industry. To study the characteristics of electromagnetic wave propagation in a chemical reaction is critical to solve the problems. The research on the characteristics of electromagnetic wave propagation in the unimolecular reaction that is a simple model reaction, can be generalized to the research in a chemical reaction. The approximate expressions of the attenuation and dispersion characteristics of electromagnetic wave propagation in the unimolecular reaction are derived by the nonlinear propagation theory. Specially, when the reaction rate is zero, the derived approximate expressions can be reduced to the formulas in low-loss dispersive media. Moreover, a 1D mold is used to validate the feasibility of the approximate expressions. The influences of the reaction rate and initial reactant concentration on the characteristics are obtained.

  16. Characteristics of Entrepreneurs: Implications for Vocational Guidance.

    ERIC Educational Resources Information Center

    Jacobowitz, Alan; Vidler, Derek C.

    1982-01-01

    Small business managers (N=430) were administered structured questionnaires through informal interviews to study the nature of the entrepreneur. Results indicated certain common characteristics, patterns of behavior, values and attitudes among entrepreneurs, and similarities in personality profiles. (RC)

  17. Section 10: Ground Water - Waste Characteristics & Targets

    EPA Pesticide Factsheets

    HRS Training. The waste characteristics factor category in the ground water pathway is made up of two components: the toxicity/mobility of the most hazardous substance associated with the site and the hazardous waste quantity at the site.

  18. Characteristics of Extreme Auroral Charging Events

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Willis, Emily; Parker, Linda Neergaard

    2014-01-01

    Today’s presentation describes preliminary results from a study of extreme auroral charging in low Earth orbit. Goal of study is to document characteristics of auroral charging events of importance to spacecraft design, operations, and anomaly investigations.

  19. 30 CFR 7.405 - Critical characteristics.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... flame-resistance test. ... of manufactured electric cable, signaling cable, or splice made from a splice kit shall be flame tested, or (b) A sample of the materials that contribute to the flame-resistant characteristic of the...

  20. 30 CFR 7.405 - Critical characteristics.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... flame-resistance test. ... of manufactured electric cable, signaling cable, or splice made from a splice kit shall be flame tested, or (b) A sample of the materials that contribute to the flame-resistant characteristic of the...

  1. 30 CFR 7.405 - Critical characteristics.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... flame-resistance test. ... of manufactured electric cable, signaling cable, or splice made from a splice kit shall be flame tested, or (b) A sample of the materials that contribute to the flame-resistant characteristic of the...

  2. Properties and characteristics of optical glass

    SciTech Connect

    Marker, A.J. III.

    1988-01-01

    This book contains the proceedings of SPIE on properties and characteristics of optical glass. Topics covered include IR reflectance measurement of ion-implanted silica, specifying optical materials, and impurity absorption coefficient measurements in phosphate glass melted under oxidizing conditions.

  3. Special Consolidated Checklists for Toxicity Characteristics Revisions

    EPA Pesticide Factsheets

    This checklist consolidates the changes to the Federal code addressed by the Toxicity Characteristic (TC) Rule [55 FR 11798; March 29, 1990; Revision Checklist 74] and subsequent revisions which have occurred through December 31, 2002.

  4. Characteristics of Entrepreneurs: Implications for Vocational Guidance.

    ERIC Educational Resources Information Center

    Jacobowitz, Alan; Vidler, Derek C.

    1982-01-01

    Small business managers (N=430) were administered structured questionnaires through informal interviews to study the nature of the entrepreneur. Results indicated certain common characteristics, patterns of behavior, values and attitudes among entrepreneurs, and similarities in personality profiles. (RC)

  5. Characteristics of high-tension magnetos

    NASA Technical Reports Server (NTRS)

    Silsbee, F B

    1920-01-01

    This report gives the results of an investigation made into the fundamental physical characteristics of high-tension ignition magnetos, and also describes the methods used for measuring the quantities involved.

  6. Characteristic Energy Scales of Quantum Systems.

    ERIC Educational Resources Information Center

    Morgan, Michael J.; Jakovidis, Greg

    1994-01-01

    Provides a particle-in-a-box model to help students understand and estimate the magnitude of the characteristic energy scales of a number of quantum systems. Also discusses the mathematics involved with general computations. (MVL)

  7. Principal Characteristics of the Petroleum Market.

    ERIC Educational Resources Information Center

    Olson, Robert W.

    1982-01-01

    The major characteristics of oil marketing, with special attention to developments in the Middle East, are described. The information presented provides a firm basis for several types of instructional inquiry. (RM)

  8. Characteristic-Wave Approach Complements Modal Analysis

    NASA Technical Reports Server (NTRS)

    Zak, Michail

    1990-01-01

    Aspects of estimation of unmodeled dynamics discussed. Report discusses solution of nonhomogeneous governing matrix equation for dynamics of short vibrational pulses propagating as characteristic waves in large structure. Applied to analyze response, to repeated pulses, of beam clamped at one end and free at other. Shows all qualitative characteristics occuring under arbitrary periodic excitations of beam and those of quasi-periodic excitations, in as much as such excitations obtained by linear superpositions of periodic excitations.

  9. Dispersion Characteristics of a Dielectric Loaded Waveguide,

    DTIC Science & Technology

    1984-07-30

    NATIONAL BUREAU OF STANOAODS-1963-A ., ’I A NSWC TR 84-338 00 In ’DISPERSION CHARACTERISTICS OF A SDIELECTRIC LOADED WAVEGUIDE By H. CROSBY J. CHOE Y...4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED DISPERSION CHARACTERISTICS OF A DIELECTRIC LOADED WAVEGUIDE S. PERFORMING ORG. REPORT...SUPPLEMENTARY NOTES S. KEY WORDS (Continue on reverse aide it necessary and Identify by block number) Dielectric Loaded Waveguide ) " Resonant Cavity) a

  10. Student and Faculty Perceptions of Teacher Characteristics.

    PubMed

    Shikiar, Richard

    1976-03-01

    Both faculty and students are interested in faculty becoming better teachers. But do both students and faculty have the same perceptions of teacher characteristics? The present study attempted to answer this question by having 15 faculty members and 22 undergraduate students perform similarity judgments between each possible pair of 14 teacher types. An individual differences multidimensional scaling analysis and a post hoc analysis indicated that faculty and students had the same perceptions of teacher characteristics.

  11. Reliability characteristics in semi-Markov models

    NASA Astrophysics Data System (ADS)

    Grabski, Franciszek

    2017-07-01

    A semi-Markov (SM) process is defined by a renewal kernel and an initial distribution of states or another equivalent parameters. Those quantities contain full information about the process and they allow us to find many characteristics and parameters of the process. Constructing the semi-Markov reliability model means building the kernel of the process based on some assumptions. Many characteristics and parameters of the SM process have a natural interpretation in the semi-Markov reliability model.

  12. The prediction of radio-path characteristics

    NASA Astrophysics Data System (ADS)

    Gitina, G. M.; Kalinin, Iu. K.

    The paper examines algorithms for the long-term prediction of radio-path characteristics in the ionosphere, the main characteristic being the MUF at a given distance. The proposed approach is based on long-term memories called DATA BANKS. Attention is given to the characteritics of the various banks, including the BANK OF CITIES, the BANK OF RADIO PATHS, the REFERENCE DATA BANK, and the OUTPUT DATA BANK.

  13. Characteristics of Yerevan High Transparency Scintillators

    SciTech Connect

    Zorn, Carl; Asryan, Gegham; Egiyan, Kim; Tarverdyan, M.; Amaryan, Moscov; Amaryan, Moskov; Demirchyan, Raphael; Stepanyan, Stepan; Burkert, Volker; Sharabian, Youri

    1992-08-01

    Optical transmission, light output and time characteristics are given for long scintillator strips fabricated at the Yerevan Physics Institute using the extrusion method. It is shown that at 45% relative (to anthracene) light output, good transmission (2.5/2.9 m attenuation length with photomultiplier direct readout and 3/3.5 m attenuation length fiber readout) and time characteristics (average decay time 2.8 nsec) were obtained.

  14. New biometric modalities using internal physical characteristics

    NASA Astrophysics Data System (ADS)

    Mortenson, Juliana (Brooks)

    2010-04-01

    Biometrics is described as the science of identifying people based on physical characteristics such as their fingerprints, facial features, hand geometry, iris patterns, palm prints, or speech recognition. Notably, all of these physical characteristics are visible or detectable from the exterior of the body. These external characteristics can be lifted, photographed, copied or recorded for unauthorized access to a biometric system. Individual humans are unique internally, however, just as they are unique externally. New biometric modalities have been developed which identify people based on their unique internal characteristics. For example, "BoneprintsTM" use acoustic fields to scan the unique bone density pattern of a thumb pressed on a small acoustic sensor. Thanks to advances in piezoelectric materials the acoustic sensor can be placed in virtually any device such as a steering wheel, door handle, or keyboard. Similarly, "Imp-PrintsTM" measure the electrical impedance patterns of a hand to identify or verify a person's identity. Small impedance sensors can be easily embedded in devices such as smart cards, handles, or wall mounts. These internal biometric modalities rely on physical characteristics which are not visible or photographable, providing an added level of security. In addition, both the acoustic and impedance methods can be combined with physiologic measurements such as acoustic Doppler or impedance plethysmography, respectively. Added verification that the biometric pattern came from a living person can be obtained. These new biometric modalities have the potential to allay user concerns over protection of privacy, while providing a higher level of security.*

  15. PSC Characteristics from Satellite Observations and Simulations

    NASA Technical Reports Server (NTRS)

    Strawa, A. W.; Drdla, K.; Bokarius, K.; Fromm, M.; Alfred, J.

    2004-01-01

    POAM solar occultation observations from 1994 to present are studied for the purpose of determining Type I PSC formation characteristics and winter-long evolution. This study examines PSC observations from many years on a common basis to see if characteristics can be identified. The results show that Type Ia PSCs form at the beginning of the winter, within several days of the first drop in temperature below T_NAT, and peak early in the winter. Type Ia PSCs typically out number Ib PSCs over the winter, especially at the beginning of the winter. Type Ia and Ib PSC observations continue throughout the winter. Micro-physical models of PSC formation must match these observed characteristics. Some models predict that temperatures must be more than 5 K below T_NAT for five days before significant freezing can occur. This is not seen in the POAM observations. Differences in PSC characteristics between the first two Arctic winters (1994-1995 and 1995-1996) and later winters also suggest the influence of volcanic perturbations on PSC formation. Type Ia and Ib PSC Characteristics observed by POAM III and SAGE III for the 2002-2003 Arctic winter are compared.

  16. Characteristics of Medical Teams in Disaster.

    PubMed

    Oldenburger, David; Baumann, Andrea; Banfield, Laura

    2017-04-01

    Disasters present unique challenges for teams providing medical assistance to those populations impacted by the event. This scoping review focused on the characteristics of medical teams in disaster and how these characteristics are developed. The scoping review methods of Arksey and O'Malley were followed. An inductive thematic analysis of selected articles was used to identify recurrent themes. A total of 6,521 articles were reviewed from eight databases, yielding 33 articles. Four recurrent theme groups were identified: (1) adaptability, flexibility, and improvisation; (2) creativity and innovation; (3) experience and training; and (4) leadership and command structure. The study highlighted key characteristics identified by responders for effective team functioning and interdependence between the characteristics. It also identified the paucity of literature on the subject. Results from the study can help to guide future research and training development for medical teams in disaster. Oldenburger D , Baumann A , Banfield L . Characteristics of medical teams in disaster. Prehosp Disaster Med. 2017;32(2):195-200.

  17. [Analysis of typical mangrove spectral reflectance characteristics].

    PubMed

    Yu, Xiang; Zhang, Feng-Shou; Liu, Qing; Li, De-Yi; Zhao, Dong-Zhi

    2013-02-01

    Acquisition of mangrove spectrum properties and detecting the sensitive bands provide technology basis for inverse modeling and estimation by remote sensing for various indexes of mangrove. The typical mangroves of Guangxi Shankou Mangrove Reserve were taken for study objects, the standard spectrum curves of Bruguiera gymnorrhiza (Linn.) Savigny, Rhizophora stylosa, Kandelia candel, Avicennia marina, Aegiceras corniculatum, Spartina anglica and mudflat were gained by denoising analysis of field-measured spectrum curves acquired by ASD FieldSpec 2. Analyzing the spectral characteristics and their differences, the authors found that the spectrum curves for various kinds of mangrove are coincident, the bands that appeared with reflection peaks and reflection valleys are basically identical, the within-class differentiated characteristics are comparatively small, the spectrum characteristics of mangroves are obviously different with Spartina anglica and mudflat. In order to gain the quantitative description for within-class differentiated characteristics of mangrove, space distance method, correlation coefficient method and spectral angle mapping method were used to calculate the within-class differentiated characteristics. The division accuracy of correlation coefficient method is higher than spectral angle mapping method which is higher than space distance method, and the result indicates that the spectrum differences of within-class mangrove and Spartina anglica are relatively small with correlation coefficients more than 0.995, and spectrum curve angle cosine values more than 0.95.

  18. Characteristic model of travelling wave ultrasonic motor.

    PubMed

    Jingzhuo, Shi; Dongmei, You

    2014-02-01

    In general, the design and analysis of ultrasonic motor and motor's control strategy are based on mathematical model. The academic model is widely used in the analysis of traveling wave ultrasonic motor (TWUSM). But the dispersive characteristic of piezoelectric ceramics and other complicated process, such as the friction, make the model's precision not so accurate. On the other hand, identification modeling method, which is built based on the tested data, has obtained increasing application in the study of ultrasonic motor's control technology. Based on the identification model, many control strategies can be designed easily. But the identification model is an approximate model, so if a more accurate model of ultrasonic motor can be obtained, the analysis and design of motor control system will be more effective. Characteristic model is a kind of identification model which can accurately describe the characteristics of TWUSM. Based on the tested data, this paper proposes the modeling method of ultrasonic motor's characteristic model. The paper also makes a comparison of the effectiveness of different identification algorithms. Aiming at the speed control of ultrasonic motor, the influence of the parameter's initial values on the precision of model is discussed. The calculating results indicate the availability of this characteristic model.

  19. Learner characteristics involved in distance learning

    SciTech Connect

    Cernicek, A.T.; Hahn, H.A.

    1991-01-01

    Distance learning represents a strategy for leveraging resources to solve educational and training needs. Although many distance learning programs have been developed, lessons learned regarding differences between distance learning and traditional education with respect to learner characteristics have not been well documented. Therefore, we conducted a survey of 20 distance learning professionals. The questionnaire was distributed to experts attending the second Distance Learning Conference sponsored by Los Alamos National Laboratory. This survey not only acquired demographic information from each of the respondents but also identified important distance learning student characteristics. Significant distance learner characteristics, which were revealed statistically and which influence the effectiveness of distance learning, include the following: reading level, student autonomy, and self-motivation. Distance learning cannot become a more useful and effective method of instruction without identifying and recognizing learner characteristics. It will be important to consider these characteristics when designing all distance learning courses. This paper will report specific survey findings and their implications for developing distance learning courses. 9 refs., 6 tabs.

  20. Mexican-American Adolescents’ Gender-Typed Characteristics: The Role of Sibling and Friend Characteristics

    PubMed Central

    Wheeler, Lorey A.; Updegraff, Kimberly A.; Schaefer, David R.

    2016-01-01

    This study examined the role of sibling and friend characteristics in Mexican-American youth’s gender-typed characteristics (i.e., attitudes, interests, and leisure activities) in early versus middle adolescence using a sibling design. Mexican-American 7th graders (M = 12.51 years; SD = .58) and their older siblings (M = 15.48 years; SD = 1.57) from 246 families participated in home interviews and a series of seven nightly phone calls. Results revealed that younger/early adolescent siblings reported more traditional gender role attitudes than their older/middle adolescent siblings and older brothers were more traditional in their attitudes than older sisters. When comparing siblings’ gender-typed interests and leisure activities, boys reported more masculine orientations than girls and girls reported more feminine orientations than boys. Older brothers’ gender-typed characteristics were associated with the amount of time spent with and gender characteristics of their friendship group, but for younger brothers, sibling characteristics were associated with their gender-typed characteristics. In contrast, both sibling and friendship characteristics were significantly associated with older and younger sisters’ gender-typed characteristics. The discussion addressed the different correlates of older and younger sisters’ and brothers’ gender-typed characteristics. PMID:25539774

  1. Mexican-American Adolescents' Gender-Typed Characteristics: The Role of Sibling and Friend Characteristics.

    PubMed

    Perez-Brena, Norma J; Wheeler, Lorey A; Updegraff, Kimberly A; Schaefer, David R

    2015-07-01

    This study examined the role of sibling and friend characteristics in Mexican-American youth's gender-typed characteristics (i.e., attitudes, interests, and leisure activities) in early versus middle adolescence using a sibling design. Mexican-American 7th graders (M = 12.51 years; SD = .58) and their older siblings (M = 15.48 years; SD = 1.57) from 246 families participated in home interviews and a series of seven nightly phone calls. Results revealed that younger/early adolescent siblings reported more traditional gender role attitudes than their older/middle adolescent siblings and older brothers were more traditional in their attitudes than older sisters. When comparing siblings' gender-typed interests and leisure activities, boys reported more masculine orientations than girls and girls reported more feminine orientations than boys. Older brothers' gender-typed characteristics were associated with the amount of time spent with and gender characteristics of their friendship group, but for younger brothers, sibling characteristics were associated with their gender-typed characteristics. In contrast, both sibling and friendship characteristics were significantly associated with older and younger sisters' gender-typed characteristics. The discussion addressed the different correlates of older and younger sisters' and brothers' gender-typed characteristics.

  2. Load characteristics of an ETS home

    SciTech Connect

    Solomon, J.S.; Blabac, S.B. )

    1987-01-01

    The authors discuss the use of a Metretek solid state, four channel data recorder to monitor the load characteristics of a home equipped with electric thermal storage (ETS) room units. Previous studies monitored the load characteristics of homes equipped with electric resistance heat (non-ETS systems). This paper focuses on one of the homes where a Metretek recorder is being used. It is a retrofit home, originally equipped with resistance heat. After moving into the home and discovering the cost to keep their home warm, the owners looked for alternatives. They became aware of ETS and installed it in the home. The homeowners have been very happy with the change and have saved money. This paper describes in detail the home, the ETS conversion, and presents the load characteristics of this home.

  3. [Mechanical buffering characteristics of feline paw pads].

    PubMed

    Zhang, Xiaopeng; Yang, Jialing; Yu, Hui

    2012-12-01

    In the long time of natural evolution, the bodies of some animals, such as feline, that live in the wild and complicate surroundings have evolved to possess outstanding buffering characteristics, which make the animals adapt to the environment perfectly. These animals generally have well-developed paw pads under their soles to play an important role in attenuating the intensity of impact when they land on the ground. Investigating the buffering characteristics of these animals' paw pads could help us to design "bionic" buffering and energy-absorption devices. In this paper, based on observations of animal jumping test, a simple mass-spring-buffer model was proposed to explore the buffering characteristics of the animals' paw pads. By analytically solving the differential equations of this model, the parameters concerned with paw pads functions were discussed and some significant results were obtained.

  4. Damping characteristics of damaged fiber composite components

    NASA Technical Reports Server (NTRS)

    Eberle, K.

    1986-01-01

    Defects in fiber composite components produce changes with respect to the vibrational characteristics of the material. These changes can be recognized in the form of a frequency shift or an alteration of the damping process. The present investigation is concerned with questions regarding the possibility of a utilization of the changes in suitable defect-detecting inspection procedures. A description is given of a method for measuring the damping characteristics of a specimen. This method provides a spectrum of the damping coefficients of the sample as a basis for a comprehensive evaluation of the damping behavior. The correlation between defects and change in the damping characteristics is demonstrated with the aid of results obtained in measurements involving specimens of carbon-fiber composites and a component consisting of glass-fiber-reinforced plastics.

  5. Characteristics of the General Physics student population.

    NASA Astrophysics Data System (ADS)

    Hunt, Gary L.

    2006-12-01

    Are pre-medical students different than the other students in a General physics class? They often appear to be different, based on how often they seek help from the instructor or how nervous they are about 2 points on a lab report. But are these students different in a measurable characteristic? The purpose of this study is to better understand the characteristics of the students in the introductory physics classes. This is the first step toward improving the instruction. By better understanding the students the classroom, the organization and pedagogy can be adjusted to optimize student learning. The characteristics to be investigated during this study are: · student epistemological structure, · student attitudes, · science course preparation prior to this course, · study techniques used, · physics concepts gained during the class · performance in the class. The data will be analyzed to investigate differences between groups. The groups investigated will be major, gender, and traditional/nontraditional students.

  6. Characteristics of dual swirlers sprayer device

    NASA Astrophysics Data System (ADS)

    Chen, Hong; Chin, Jushan

    1991-07-01

    The spray characteristics of dual radial swirlers mixing-cup sprayer device have been investigated with the aid of Malvern laser granulometer and the differences of its spray characteristics from those of the pressure atomizing fuel nozzle were determined. Two air flow proportions of the first swirler to the second one are 50:50 percent and 30:70 percent. The airflow velocity at the exit section has been designed in the range 37 to 74 m/s. In the tests the fuel pressure ranges from 294,000 to 441,000 Pa. The test results show that, in the case of reasonable desing, the sprayer device is able to provide better spray characteristics than pressure atomizing fuel nozzle.

  7. Characteristic formulation for metric f (R ) gravity

    NASA Astrophysics Data System (ADS)

    Mongwane, Bishop

    2017-07-01

    In recent years, the characteristic formulation of numerical relativity has found increasing use in the extraction of gravitational radiation from numerically generated spacetimes. In this paper, we formulate the characteristic initial value problem for f (R ) gravity. We consider, in particular, the vacuum field equations of Metric f (R ) gravity in the Jordan frame, without utilizing the dynamical equivalence with scalar-tensor theories. We present the full hierarchy of nonlinear hypersurface and evolution equations necessary for numerical implementation in both tensorial and eth forms. Furthermore, we specialize the resulting equations to situations where the spacetime is almost Minkowski and almost Schwarszchild using standard linearization techniques. We obtain analytic solutions for the dominant ℓ=2 mode and show that they satisfy the concomitant constraints. These results are ideally suited as testbed solutions for numerical codes. Finally, we point out that the characteristic formulation can be used as a complementary analytic tool to the 1 +1 +2 semitetrad formulation.

  8. Analysis of Petal Rotation Trajectory Characteristics

    NASA Technical Reports Server (NTRS)

    Anderson, Rodney L.; Campagnola, Stefano; Buffington, Brent B.

    2014-01-01

    In this study, the characteristics of petal rotation trajectories are explored in both the two-body and circular restricted three-body problem (CRTBP) models. Petal rotation trajectories alternate long and short resonances of different kinds to rotate the line of apsides. They are typically computed using the patched conic model, and they are used in a number of different missions and mission concepts including Cassini, JUICE, and Europa mission concepts. Petal rotation trajectories are first analyzed here using the patched conic model to quantify their characteristics and search for cases with fast rotation of the line of apsides. When they are computed in the CRTBP, they are unstable periodic orbits with corresponding stable and unstable manifolds. The characteristics of these orbits are explored from a dynamical systems perspective in the second phase of the study.

  9. Spray Behavior and Atomization Characteristics of Biodiesel

    NASA Astrophysics Data System (ADS)

    Choi, Seung-Hun; Oh, Young-Taig

    Biodiesel has large amount of oxygen in itself, which make it very efficient in reducing exhaust emission by improving combustion inside an engine. But biodiesel has a low temperature flow problem because it has a high viscosity. In this study, the spray behavior and atomization characteristics were investigated to confirm of some effect for the combination of non-esterification biodiesel and fuel additive WDP and IPA. The process of spray was visualized through the visualization system composed of a halogen lamp and high speed camera, and atomization characteristics were investigated through LDPA. When blending WDP and IPA with biodiesel, atomization and spray characteristics were improved. Through this experimental result, SMD of blended fuel, WDP 25% and biodiesel 75%, was 33.9% reduced at distance 6cm from a nozzle tip under injection pressure 30MPa.

  10. Cultural characteristics of nursing practice in Japan.

    PubMed

    Tsujimura, Mayuko; Ishigaki, Kazuko; Yamamoto-Mitani, Noriko; Fujita, Junko; Katakura, Naoko; Ogata, Yasuko; Mochizuki, Yuki; Okamoto, Yuko; Shinohara, Yuko

    2016-04-01

    The population of Japan has become multi-cultural, and there is more demand for culturally competent nursing care. The purpose of this study was to explore cultural characteristics of nursing practice in Japan focusing on behaviour. We interviewed 25 professionals with experience in or knowledge of nursing practice both in Japan and either the United States, the United Kingdom, Sweden, Thailand or South Korea. Qualitative content analysis has yielded three themes for cultural characteristics of nursing practice in Japan: practice expectations, communication and relationships with patients. Practice expectations for nurses in Japan involved various aspects; nurses conducted a wide range of basic nursing tasks, including bed baths and toileting. They often relied on non-verbal communication to deliver thoughtfulness and perceptiveness. They typically show deference to doctors and colleagues, emphasizing building and maintaining harmony with them. This emphasis on a multifaceted, non-verbal, and harmonious approach seemed characteristic of practice among Japanese nurses. © 2016 Wiley Publishing Asia Pty Ltd.

  11. Fractal characteristics for binary noise radar waveform

    NASA Astrophysics Data System (ADS)

    Li, Bing C.

    2016-05-01

    Noise radars have many advantages over conventional radars and receive great attentions recently. The performance of a noise radar is determined by its waveforms. Investigating characteristics of noise radar waveforms has significant value for evaluating noise radar performance. In this paper, we use binomial distribution theory to analyze general characteristics of binary phase coded (BPC) noise waveforms. Focusing on aperiodic autocorrelation function, we demonstrate that the probability distributions of sidelobes for a BPC noise waveform depend on the distances of these sidelobes to the mainlobe. The closer a sidelobe to the mainlobe, the higher the probability for this sidelobe to be a maximum sidelobe. We also develop Monte Carlo framework to explore the characteristics that are difficult to investigate analytically. Through Monte Carlo experiments, we reveal the Fractal relationship between the code length and the maximum sidelobe value for BPC waveforms, and propose using fractal dimension to measure noise waveform performance.

  12. Flood-frequency characteristics of Wisconsin streams

    USGS Publications Warehouse

    Walker, John F.; Peppler, Marie C.; Danz, Mari E.; Hubbard, Laura E.

    2017-05-22

    Flood-frequency characteristics for 360 gaged sites on unregulated rural streams in Wisconsin are presented for percent annual exceedance probabilities ranging from 0.2 to 50 using a statewide skewness map developed for this report. Equations of the relations between flood-frequency and drainage-basin characteristics were developed by multiple-regression analyses. Flood-frequency characteristics for ungaged sites on unregulated, rural streams can be estimated by use of the equations presented in this report. The State was divided into eight areas of similar physiographic characteristics. The most significant basin characteristics are drainage area, soil saturated hydraulic conductivity, main-channel slope, and several land-use variables. The standard error of prediction for the equation for the 1-percent annual exceedance probability flood ranges from 56 to 70 percent for Wisconsin Streams; these values are larger than results presented in previous reports. The increase in the standard error of prediction is likely due to increased variability of the annual-peak discharges, resulting in increased variability in the magnitude of flood peaks at higher frequencies. For each of the unregulated rural streamflow-gaging stations, a weighted estimate based on the at-site log Pearson type III analysis and the multiple regression results was determined. The weighted estimate generally has a lower uncertainty than either the Log Pearson type III or multiple regression estimates. For regulated streams, a graphical method for estimating flood-frequency characteristics was developed from the relations of discharge and drainage area for selected annual exceedance probabilities. Graphs for the major regulated streams in Wisconsin are presented in the report.

  13. Occupations, work characteristics and common mental disorder.

    PubMed

    Stansfeld, S A; Pike, C; McManus, S; Harris, J; Bebbington, P; Brugha, T; Hassiotis, A; Jenkins, R; Meltzer, H; Moran, P; Clark, C

    2013-05-01

    The present study aimed to assess the prevalence of common mental disorders (CMDs) by occupation in a representative sample of the English adult population. Another aim was to examine whether the increased risk of CMD in some occupations could be explained by adverse work characteristics. Method We derived a sample of 3425 working-age respondents from the Adult Psychiatric Morbidity Survey 2007. Occupations were classified by Standard Occupational Classification group, and CMD measured by the Revised Clinical Interview Schedule. Job characteristics were measured by questionnaire, and tested as explanatory factors in associations of occupation and CMD. After adjusting for age, gender, housing tenure and marital status, caring personal service occupations had the greatest risk of CMD compared with all occupations (odds ratio 1.73, 95% confidence interval 1.16-2.58). The prevalence of adverse psychosocial work characteristics did not follow the pattern of CMD by occupation. Work characteristics did not explain the increased risk of CMDs associated with working in personal service occupations. Contrary to our hypotheses, adding work characteristics individually to the association of occupation and CMD tended to increase rather than decrease the odds for CMD. As has been found by others, psychosocial work characteristics were associated with CMD. However, we found that in our English national dataset they could not explain the high rates of CMD in particular occupations. We suggest that selection into occupations may partly explain high CMD rates in certain occupations. Also, we did not measure emotional demands, and these may be important mediators of the relationship between occupation type and CMDs.

  14. Field determination of metal oxide varistor characteristics

    SciTech Connect

    Anderson, J.G.; Kresge, J.S.; Lambert, S.R.; Sakshaug, E.C. ); Woodward, R.C. ); Forston, H.S. Jr. )

    1992-04-01

    Mismatched parallel-connected varistors or a change in unit characteristics could lead to unequal energy sharing and ultimate block failure. This project, involving laboratory tests on a variety of blocks as well as evaluation of methods to determine failed blocks, indicates that caution is advised in parallel group applications. The project team developed one method of measuring varistor conduction characteristics and performed preliminary field trails. In addition, a series of laboratory tests was performed on representative block obtained from four different manufacturers. These laboratory tests attempted to duplicate the duty that blocks could experience so that changes in characteristics under operation could be anticipated. A block that has cracked due to mechanical shock or thermal effects caused by the application of too much energy in too short a time period is very difficult to detect. The most satisfactory method of detection is application of a 10 kA impulse to the column with a test generator. If a block is cracked, the 10 kA impulse will likely result in a block flashover that can be detected. The field testing of multicolumn applications-for example, series capacitor bank protection-resulted in two promising approaches. The first involves monitoring the rate of energy input into the column during operation and inferring, based on the information that the block would likely have been damaged (cracked). This approach relies on shifts in energy sharing between columns to identify characteristics changes in blocks. The second approach involves applying impulse currents to columns to determine electrical (voltage versus current) characteristics and thereby detect cracked blocks. This approach has merit for defining characteristic changes that would lower the installation's capacity to absorb energy.

  15. Static Characteristics of the Ferroelectric Transistor Inverter

    NASA Technical Reports Server (NTRS)

    Mitchell, Cody; Laws, crystal; MacLeond, Todd C.; Ho, Fat D.

    2010-01-01

    The inverter is one of the most fundamental building blocks of digital logic, and it can be used as the foundation for understanding more complex logic gates and circuits. This paper presents the characteristics of an inverter circuit using a ferroelectric field-effect transistor. The voltage transfer characteristics are analyzed with respect to varying parameters such as supply voltage, input voltage, and load resistance. The effects of the ferroelectric layer between the gate and semiconductor are examined, and comparisons are made between the inverters using ferroelectric transistors and those using traditional MOSFETs.

  16. Reionization: Characteristic Scales, Topology And Observability

    SciTech Connect

    Iliev, Ilian T.; Shapiro, Paul R.; Mellema, Garrelt; Pen, Ue-Li; McDonald, Patrick; Alvarez, Marcelo A.; /KIPAC, Menlo Park

    2007-11-02

    Recently the numerical simulations of the process of reionization of the universe at z > 6 have made a qualitative leap forward, reaching sufficient sizes and dynamic range to determine the characteristic scales of this process. This allowed making the first realistic predictions for a variety of observational signatures. We discuss recent results from large-scale radiative transfer and structure formation simulations on the observability of high-redshift Ly-{alpha} sources. We also briefly discuss the dependence of the characteristic scales and topology of the ionized and neutral patches on the reionization parameters.

  17. Lung cancer stem cells—characteristics, phenotype

    PubMed Central

    George, Rachel; Sethi, Tariq

    2016-01-01

    Lung cancer remains a major cause of cancer-related deaths worldwide with unfavourable prognosis mainly due to the late stage of disease at presentation. High incidence and disease recurrence rates are a fact despite advances in treatment. Ongoing experimental and clinical observations suggest that the malignant phenotype in lung cancer is sustained by lung cancer stem cells (CSCs) which are putative stem cells situated throughout the airways that have the potential of initiating lung cancer formation. These cells share the common characteristic of increased proliferation and differentiation, long life span and resistance to chemotherapy and radiation therapy. This review summarises the current knowledge on their characteristics and phenotype. PMID:27413709

  18. Low-flow characteristics of Virginia streams

    USGS Publications Warehouse

    Austin, Samuel H.; Krstolic, Jennifer L.; Wiegand, Ute

    2011-01-01

    Low-flow annual non-exceedance probabilities (ANEP), called probability-percent chance (P-percent chance) flow estimates, regional regression equations, and transfer methods are provided describing the low-flow characteristics of Virginia streams. Statistical methods are used to evaluate streamflow data. Analysis of Virginia streamflow data collected from 1895 through 2007 is summarized. Methods are provided for estimating low-flow characteristics of gaged and ungaged streams. The 1-, 4-, 7-, and 30-day average streamgaging station low-flow characteristics for 290 long-term, continuous-record, streamgaging stations are determined, adjusted for instances of zero flow using a conditional probability adjustment method, and presented for non-exceedance probabilities of 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.05, 0.02, 0.01, and 0.005. Stream basin characteristics computed using spatial data and a geographic information system are used as explanatory variables in regional regression equations to estimate annual non-exceedance probabilities at gaged and ungaged sites and are summarized for 290 long-term, continuous-record streamgaging stations, 136 short-term, continuous-record streamgaging stations, and 613 partial-record streamgaging stations. Regional regression equations for six physiographic regions use basin characteristics to estimate 1-, 4-, 7-, and 30-day average low-flow annual non-exceedance probabilities at gaged and ungaged sites. Weighted low-flow values that combine computed streamgaging station low-flow characteristics and annual non-exceedance probabilities from regional regression equations provide improved low-flow estimates. Regression equations developed using the Maintenance of Variance with Extension (MOVE.1) method describe the line of organic correlation (LOC) with an appropriate index site for low-flow characteristics at 136 short-term, continuous-record streamgaging stations and 613 partial-record streamgaging stations. Monthly

  19. Abdominal vascular syndromes: characteristic imaging findings.

    PubMed

    Cardarelli-Leite, Leandro; Velloni, Fernanda Garozzo; Salvadori, Priscila Silveira; Lemos, Marcelo Delboni; D'Ippolito, Giuseppe

    2016-01-01

    Abdominal vascular syndromes are rare diseases. Although such syndromes vary widely in terms of symptoms and etiologies, certain imaging findings are characteristic. Depending on their etiology, they can be categorized as congenital-including blue rubber bleb nevus syndrome, Klippel-Trenaunay syndrome, and hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber syndrome)-or compressive-including "nutcracker" syndrome, median arcuate ligament syndrome, Cockett syndrome (also known as May-Thurner syndrome), and superior mesenteric artery syndrome. In this article, we aimed to illustrate imaging findings that are characteristic of these syndromes, through studies conducted at our institution, as well as to perform a brief review of the literature on this topic.

  20. USB flow characteristics related to noise generation

    NASA Technical Reports Server (NTRS)

    Brown, W. H.; Reddy, N. N.

    1976-01-01

    The effects of nozzle and flap geometry on upper surface blown flow field characteristics related to noise generation were examined experimentally using static models. Flow attachment and spreading characteristics were observed using flow visualization techniques. Velocity and turbulence profiles in the trailing edge wake were measured using hot-wire anemometry, and the effects of the geometric variables on peak velocity and turbulence intensity were determined. It is shown that peak trailing edge velocity is a function of the ratio of flow length to modified hydraulic diameter.

  1. Characteristics of primary electric propulsion systems. [conferences

    NASA Technical Reports Server (NTRS)

    Byers, D. C.

    1979-01-01

    The use of advanced electric propulsion systems is expected to provide cost and performance benefits for future energetic space missions. A methodology to predict the characteristics of advanced electric propulsion systems was developed and programmed for computer calculations to allow evaluation of a broad set of technology and mission assumptions. The impact on overall thrust system characteristics was assessed for variations of propellant type, total accelerating voltage, thruster area, specific impulse, and power system approach. The data may be used both to provide direction to technology emphasis and allow for preliminary estimates of electric propulsion system properties for a wide variety of applications.

  2. Remote sensing of Mississippi River characteristics

    NASA Technical Reports Server (NTRS)

    Ruff, J. F.; Skinner, M. M.; Winkley, B. R.; Simons, D. B.; Dorratcague, D. E.

    1975-01-01

    A data collection program initiated by the Vicksburg District, to develop a workable knowledge of the principles relating to the transport of water and sediment to gain a better understanding of the Mississippi River characteristics is introduced. Aerial photographs and thermal infrared imagery were collected over two test reaches at low and high water stages. Qualitative interpretation of the data relates to the river characteristics such as flow patterns, relative velocities, sediment concentration distribution, water-depth effects, and effects of man made structures. Ground truth information is correlated with the remotely sensed data.

  3. Modelling of dc characteristics for granular semiconductors

    NASA Astrophysics Data System (ADS)

    Varpula, Aapo; Sinkkonen, Juha; Novikov, Sergey

    2010-11-01

    The dc characteristics of granular n-type semiconductors are calculated analytically with the drift-diffusion theory. Electronic trapping at the grain boundaries (GBs) is taken into account. The use of quadratic and linear GB potential profiles in the calculation is compared. The analytical model is verified with numerical simulation performed by SILVACO ATLAS. The agreement between the analytical and numerical results is excellent in a large voltage range. The results show that electronic trapping at the GBs has a remarkable effect on the highly nonlinear I-V characteristics of the material.

  4. Acoustic Characteristics of Sentences Produced in Noise

    DTIC Science & Technology

    1989-09-01

    MONITORING OPOANIZATION REPORT NUMIIIIR( S ) AAMRL-TR-89- 036 1 ao.rNAM OF P1 ORM IN G ORGANIZATION 6 .OFFICE SY B L U , NAME OF MNITORIN G 6ORANIZA7IONary...and aerodynamic characteristics of pharyngeal consonants in Iraqi Arabic," Phonetica, 44, 156-172. 4. Cyphers, D . S ., Kassel, R. H., Kaufman, D . Hd...AAMRL-TR-89-036 AD-A235 344UIl IIIIII 11111111 liii III!l ~ l!l ACOUSTIC CHARACTERISTICS OF SENTENCES PRODUCED IN NOISE Z, S . Bond Thomas J. Moore

  5. Tribotechnical characteristics of titanium diboride electrospark coatings

    SciTech Connect

    Polotai, V.V.; Chiplik, V.N.; Egorov, F.F.; Podchernyaeva, I.A.; Verkhoturov, A.D.

    1985-10-01

    The most important characteristics of electrospark coatings are wear resistance and coefficient of friction. However, information on the tribotechnical properties of electrospark coatings is extremely limited in the literature, in part due to methodological difficulties caused by the insignificant thickness of electrospark coatings, as a rule, 40-60 mum and less. In this work a study was made of the tribotechnical characteristics of 45 steel after electroerosion hardening with TiB2-Mo alloys with a volume share of molybdenum in the original charge of 5, 10, 20, 30 and 50%. For comparison, specimens with coatings of the standard sintered carbides VK6 and T15K6 were also tested.

  6. Switching Characteristics of Ferroelectric Transistor Inverters

    NASA Technical Reports Server (NTRS)

    Laws, Crystal; Mitchell, Coey; MacLeod, Todd C.; Ho, Fat D.

    2010-01-01

    This paper presents the switching characteristics of an inverter circuit using a ferroelectric field effect transistor, FeFET. The propagation delay time characteristics, phl and plh are presented along with the output voltage rise and fall times, rise and fall. The propagation delay is the time-delay between the V50% transitions of the input and output voltages. The rise and fall times are the times required for the output voltages to transition between the voltage levels V10% and V90%. Comparisons are made between the MOSFET inverter and the ferroelectric transistor inverter.

  7. Dispersivity as an oil reservoir rock characteristic

    SciTech Connect

    Menzie, D.E.; Dutta, S.

    1989-12-01

    The main objective of this research project is to establish dispersivity, {alpha}{sub d}, as an oil reservoir rock characteristic and to use this reservoir rock property to enhance crude oil recovery. A second objective is to compare the dispersion coefficient and the dispersivity of various reservoir rocks with other rock characteristics such as: porosity, permeability, capillary pressure, and relative permeability. The dispersivity of a rock was identified by measuring the physical mixing of two miscible fluids, one displacing the other in a porous medium. 119 refs., 27 figs., 12 tabs.

  8. Identifying characteristic scales in the human genome

    NASA Astrophysics Data System (ADS)

    Carpena, P.; Bernaola-Galván, P.; Coronado, A. V.; Hackenberg, M.; Oliver, J. L.

    2007-03-01

    The scale-free, long-range correlations detected in DNA sequences contrast with characteristic lengths of genomic elements, being particularly incompatible with the isochores (long, homogeneous DNA segments). By computing the local behavior of the scaling exponent α of detrended fluctuation analysis (DFA), we discriminate between sequences with and without true scaling, and we find that no single scaling exists in the human genome. Instead, human chromosomes show a common compositional structure with two characteristic scales, the large one corresponding to the isochores and the other to small and medium scale genomic elements.

  9. Language Characteristics of Individuals with Down Syndrome

    PubMed Central

    Martin, Gary E.; Klusek, Jessica; Estigarribia, Bruno; Roberts, Joanne E.

    2009-01-01

    On average, language and communication characteristics of individuals with Down syndrome (the most common genetic cause of intellectual disability) follow a consistent profile. Despite considerable individual variability, receptive language is typically stronger than expressive language, with particular challenges in phonology and syntax. We review the literature on language and literacy skills of individuals with Down syndrome, with emphasis on the areas of phonology, vocabulary, syntax, and pragmatics. We begin by describing the hearing, oral-motor, cognitive, social, and prelinguistic and early nonverbal communication characteristics of individuals with Down syndrome. We conclude with a discussion of clinical implications and research directions. PMID:20428477

  10. Investigation of vibration characteristics of electric motors

    NASA Technical Reports Server (NTRS)

    Bakshis, A. K.; Tamoshyunas, Y. K.

    1973-01-01

    The vibration characteristics of electric motors were analyzed using mathematical statistics methods. The equipment used and the method of conducting the test are described. Curves are developed to show the visualization of the electric motor vibrations in the vertical direction. Additional curves are included to show the amplitude-phase frequency characteristic of dynamic rotor-housing vibrations at the first lug and the same data for the second lug of the electric motor. Mathematical models were created to show the transmission function of the dynamic rotor housing system.

  11. Gas hydrate reservoir characteristics and economics

    SciTech Connect

    Collett, T.S.; Bird, K.J.; Burruss, R.C.; Lee, Myung W.

    1992-06-01

    The primary objective of the DOE-funded USGS Gas Hydrate Program is to assess the production characteristics and economic potential of gas hydrates in northern Alaska. The objectives of this project for FY-1992 will include the following: (1) Utilize industry seismic data to assess the distribution of gas hydrates within the nearshore Alaskan continental shelf between Harrison Bay and Prudhoe Bay; (2) Further characterize and quantify the well-log characteristics of gas hydrates; and (3) Establish gas monitoring stations over the Eileen fault zone in northern Alaska, which will be used to measure gas flux from destabilized hydrates.

  12. Gas hydrate reservoir characteristics and economics

    SciTech Connect

    Collett, T.S.; Bird, K.J.; Burruss, R.C.; Lee, Myung W.

    1992-01-01

    The primary objective of the DOE-funded USGS Gas Hydrate Program is to assess the production characteristics and economic potential of gas hydrates in northern Alaska. The objectives of this project for FY-1992 will include the following: (1) Utilize industry seismic data to assess the distribution of gas hydrates within the nearshore Alaskan continental shelf between Harrison Bay and Prudhoe Bay; (2) Further characterize and quantify the well-log characteristics of gas hydrates; and (3) Establish gas monitoring stations over the Eileen fault zone in northern Alaska, which will be used to measure gas flux from destabilized hydrates.

  13. PMR polyimide prepreg with improved tack characteristics

    NASA Technical Reports Server (NTRS)

    Serafini, T. T.; Delvigs, P.

    1976-01-01

    Current PMR Polyimide prepreg technology utilizes methanol or ethanol solvents for preparation of the PMR prepreg solutions. The volatility of these solvents limits the tack and drape retention characteristics of unprotected prepreg exposed to ambient conditions. Studies conducted to achieve PMR 15 Polyimide prepreg with improved tack and drape characteristics were described. Improved tack and drape retention were obtained by incorporation of an additional monomer. The effects of various levels of the added monomer on the thermo-oxidative stability and mechanical properties of graphite fiber reinforced PMR 15 composites exposed and tested at 316 C (600 F) were discussed.

  14. Investigation of vibration characteristics of electric motors

    NASA Technical Reports Server (NTRS)

    Bakshis, A. K.; Tamoshyunas, Y. K.

    1973-01-01

    The vibration characteristics of electric motors were analyzed using mathematical statistics methods. The equipment used and the method of conducting the test are described. Curves are developed to show the visualization of the electric motor vibrations in the vertical direction. Additional curves are included to show the amplitude-phase frequency characteristic of dynamic rotor-housing vibrations at the first lug and the same data for the second lug of the electric motor. Mathematical models were created to show the transmission function of the dynamic rotor housing system.

  15. Fusibility and sintering characteristics of ash

    SciTech Connect

    Ots, A. A.

    2012-03-15

    The temperature characteristics of ash fusibility are studied for a wide range of bituminous and brown coals, lignites, and shales with ratios R{sub B/A} of their alkaline and acid components between 0.03 and 4. Acritical value of R{sub B/A} is found at which the fusion temperatures are minimal. The sintering properties of the ashes are determined by measuring the force required to fracture a cylindrical sample. It is found that the strength of the samples increases sharply at certain temperatures. The alkali metal content of the ashes has a strong effect on their sintering characteristics.

  16. Myopia Control with Orthokeratology Contact Lenses in Spain (MCOS): Study Design and General Baseline Characteristics

    PubMed Central

    Santodomingo-Rubido, Jacinto; Villa-Collar, César; Gilmartin, Bernard; Gutiérrez-Ortega, Ramón

    2010-01-01

    Purpose Although previous studies suggest that orthokeratology contact lens wear slows eye growth in children with progressing myopia, some limitations in the methodology employed have become evident. Furthermore, the safety of this modality of visual correction has not been assessed. The study “Myopia Control with Orthokeratology Contact Lenses in Spain” (MCOS) is being conducted to compare axial length growth between white European myopic children wearing orthokeratology contact lenses (OK) and wearing distance single-vision spectacles (SV). Additionally, the incidence of adverse events and discontinuations is also recorded. We outline the methodology and baseline data adopted. Methods Subjects aged 6 to 12, with myopia ranging from 0.75 to 4.00 D and astigmatism ≤1.00 D were prospectively allocated OK or SV correction. Measurements of axial length, anterior chamber depth, corneal topography, cycloplegic autorefraction, visual acuity and corneal staining are performed at 6-month intervals. The incidence of adverse events and discontinuations are also recorded. Results Thirty one children were fitted with OK and 31 with SV correction. Eight subjects did not meet the refraction-related inclusion criteria for enrollment. No significant differences were found in baseline mean age and refractive and biometric data betwseen the two groups (P>0.05). No adverse events were found in any of the two groups at baseline. Conclusion To the authors’ knowledge, MCOS is the first prospective clinical trial to assess the safety and efficacy of orthokeratology contact lens wear to slow myopia progression vs. single-vision spectacle wear. The MCOS offers a number of notable features: prospective design; well-matched samples and high-resolution ocular biometry measures, which should collectively elucidate whether orthokeratology contact lens wear is a feasible and safe method for myopia-progression control.

  17. Young Children's Sibling Relationship Interactional Types: Associations with Family Characteristics, Parenting, and Child Characteristics

    ERIC Educational Resources Information Center

    Gamble, Wendy C.; Yu, Jeong Jin

    2014-01-01

    Research Findings: This study examines patterns of sibling relationship qualities or interactional types and their association with family characteristics, parenting, and the characteristics of 1 of those children. Participants were 65 children (34 boys; Time 1 mean age = 51 months), their mothers, fathers, and Head Start teachers. Approximately…

  18. 43 CFR 3715.2-1 - What additional characteristic(s) must my occupancy have?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false What additional characteristic(s) must my occupancy have? 3715.2-1 Section 3715.2-1 Public Lands: Interior Regulations Relating to Public Lands...(s) must my occupancy have? In addition to the requirements specified in § 3715.2, your...

  19. 43 CFR 3715.2-1 - What additional characteristic(s) must my occupancy have?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false What additional characteristic(s) must my occupancy have? 3715.2-1 Section 3715.2-1 Public Lands: Interior Regulations Relating to Public Lands...(s) must my occupancy have? In addition to the requirements specified in § 3715.2, your...

  20. Characteristic(s) of Hypermedia and How They Relate to Knowledge.

    ERIC Educational Resources Information Center

    Fastrez, Pierre

    2001-01-01

    Offers a redefining of three problem areas associated with the cognitive effects of the semiotic characteristics of hypermedia: hypertext associativity, non-linearity, and the rapprochement of real and hypertext navigation. Focuses on navigation and discusses characteristics of hypermedia and its rapport with knowledge. (Author/LRW)

  1. Approximating the head characteristics and characteristic surfaces of dynamic pumps by means of an exponential function

    NASA Astrophysics Data System (ADS)

    Shekun, G. D.

    2009-08-01

    Results obtained from statistical and experimental studies of the head characteristics of commercially available centrifugal and free-vortex pumps are presented. A regression equation in the form of an exponential function written in a reduced-relative system of coordinates for approximating the head characteristics of blade pumps is obtained.

  2. Characteristics of Positive Autobiographical Memories in Adulthood

    ERIC Educational Resources Information Center

    Bluck, Susan; Alea, Nicole

    2009-01-01

    The characteristics of positive autobiographical memory narratives were examined in younger and older adults. Narratives were content-coded for the extent to which they contained indicators of affect, sensory imagery, and cognition. Affect was additionally assessed through self-report. Young adults expressed more positive affect and less sensory…

  3. Characteristics of arachnoids from Magellan data

    NASA Technical Reports Server (NTRS)

    Dawson, C. B.; Crumpler, L. S.

    1993-01-01

    Current high resolution Magellan data enables more detailed geological study of arachnoids, first identified by Barsukov et al. as features characterized by a combination of radar-bright, concentric rings and radiating lineations, named 'arachnoids' on the basis of their spider and web-like appearance. Identification of arachnoids in Magellan data has been based on SAR images, in keeping with the original definition. However, there is some overlap by other workers in identification of arachnoids, corona (predominantly bright rings), and novae (predominantly radiating lineations), as all of these features share some common characteristics. Features used in this survey were chosen based on their classification as arachnoids in Head et al.'s catalog and on SAR characteristics matching Barsukov et al.'s original definition. The 259 arachnoids have been currently identified on Venus, all of which were considered in this study. Fifteen arachnoids from different regions, chosen for their 'type' characteristics and lack of deformation by other regional processes, were studied in depth, using SAR and altimetric data to map and profile these arachnoids in an attempt to better determine their geologic and altimetric characteristics and possible formation sequences.

  4. Incidental Learning of Sex Role Characteristics.

    ERIC Educational Resources Information Center

    Kinsell-Rainey, Lynn W.

    The content and process of incidental learning of sex role related characteristics through play behavior was explored in a study of more than 6000 toys sold by Sears, Roebuck & Company between 1900 and 1970, as represented in their mail order catalogs. Sixty percent of all toys were sex typed by Sears. The nature of the play behavior…

  5. Aerodynamic Characteristics of Tracheostomy Speaking Valves.

    ERIC Educational Resources Information Center

    Fornataro-Clerici, Lisa; Zajac, David J.

    1993-01-01

    Pressure-flow characteristics were determined for four different one-way valves (Kisner, Montgomery, Olympic, and Passy-Muir) used for speech production in tracheotomy patients. Results indicated significant differences in resistance among the valves, with the resistance of one valve substantially greater than that of the normal upper airways.…

  6. Characteristics and Quality of Autism Websites

    ERIC Educational Resources Information Center

    Reichow, Brian; Halpern, Jason I.; Steinhoff, Timothy B.; Letsinger, Nicole; Naples, Adam; Volkmar, Fred R.

    2012-01-01

    The World Wide Web is a common method for obtaining information on autism spectrum disorders, however, there are no guidelines for finding websites with high quality. We conducted two studies examining the characteristics and/or quality of autism websites in 2009 and 2010. We found websites with a .gov top-level domain had a statistically…

  7. Widowhood Fantasies: Incidence, Characteristics, and Potential Function.

    ERIC Educational Resources Information Center

    Bear, Roberta Meyer; Flowers, Barbara P.

    Although some people fantasize about their spouse's possible death, the literature contains no reports of research on widowhood fantasies. The incidence, characteristics, and possible function of these fantasies were examined in individual interviews with 28 divorced and married men and women. Interview data were analyzed by calculating chi-square…

  8. Compensatory Hypertrophy of Skeletal Muscle: Contractile Characteristics

    ERIC Educational Resources Information Center

    Ianuzzo, C. D.; Chen, V.

    1977-01-01

    Describes an experiment using rats that demonstrates contractile characteristics of normal and hypertrophied muscle. Compensatory hypertrophy of the plantaris muscle is induced by surgical removal of the synergistic gastrocnemium muscle. Includes methods for determination of contractile properties of normal and hypertrophied muscle and…

  9. Classroom Characteristics and Student Friendship Cliques.

    ERIC Educational Resources Information Center

    Hallinan, Maureen T.; Smith, Stevens S.

    This paper examines the effects of classroom characteristics on the friendship cliques of preadolescent students. It is argued that structural and organizational features of a classroom constrain the interaction patterns of students in such a way as to affect the probability of dyadic friendship relationships and the network of social ties that…

  10. Characteristics of Second Graders' Mathematical Writing

    ERIC Educational Resources Information Center

    Cohen, Jeremy A.; Casa, Tutita M.; Miller, Heather C.; Firmender, Janine M.

    2015-01-01

    This study compared the characteristics of second graders' mathematical writing between an intervention and comparison group. Two six-week Project M2 units were implemented with students in the intervention group. The units position students to communicate in ways similar to mathematicians, including engaging in verbal discourse where they…

  11. Antimicrobial Peptides with Differential Bacterial Binding Characteristics

    DTIC Science & Technology

    2013-03-01

    WITH DIFFERENTIAL BACTERIAL BINDING CHARACTERISTICS by Laurel A. Doherty Morris Slutsky and Jason W. Soares March 2013...per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and...AUTHOR(S) Laurel A. Doherty , Morris Slutsky*, and Jason W. Soares 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING

  12. Linear and nonlinear stability characteristics of whistlers

    NASA Technical Reports Server (NTRS)

    Brinca, A. L.

    1972-01-01

    Linear and nonlinear propagating characteristics of right-hand polarized, slow electromagnetic, magnetoplasma waves (whistlers) are discussed in terms of stability and dispersion. An analysis of the stability of whistlers propagating at an angle to the static magnetic field is presented. A new mechanism is derived for the onset of stimulated emissions, and modulational instability for nonlinear whistlers are discussed.

  13. Characteristics of the Romanian energy market

    NASA Astrophysics Data System (ADS)

    Stet, M.

    2017-05-01

    This paper highlights the main characteristics of the energy market in Romania. Starting from the mode of organization and operation of the electricity market, there are revealed prices and tariffs for electricity for different categories of customers and their evolution in time. There are pointed also ways of setting electricity prices and tariffs, taking into account the expenditures actually recorded by economic operators.

  14. Assessment of railway wagon suspension characteristics

    NASA Astrophysics Data System (ADS)

    Soukup, Josef; Skočilas, Jan; Skočilasová, Blanka

    2017-05-01

    The article deals with assessment of railway wagon suspension characteristics. The essential characteristics of a suspension are represented by the stiffness constants of the equivalent springs and the eigen frequencies of the oscillating movements in reference to the main central inertia axes of a vehicle. The premise of the experimental determination of these characteristic is the knowledge of the gravity center position and the knowledge of the main central inertia moments of the vehicle frame. The vehicle frame performs the general spatial movement when the vehicle moves. An analysis of the frame movement generally arises from Euler's equations which are commonly used for the description of the spherical movement. This solution is difficult and it can be simplified by applying the specific assumptions. The eigen frequencies solutions and solutions of the suspension stiffness are presented in the article. The solutions are applied on the railway and road vehicles with the simplifying conditions. A new method which assessed the characteristics is described in the article.

  15. Yellow-Poplar: Characteristics and Management

    Treesearch

    Donald E. Beck; Lino Della-Bianca

    1981-01-01

    This reference tool and field guide for foresters and other landmanagers includes a synthesis of information on the characteristics of yellow-poplar with guidelines for managing the species. It is based on research conducted by many individuals in State and Federal forestry organizations and in universities throughout the Eastern United States. This handbook...

  16. 46 CFR 109.564 - Maneuvering characteristics.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.564 Maneuvering characteristics. (a) The master or person in charge of each self-propelled unit of 1,600 gross tons and over shall ensure that a maneuvering information fact sheet...

  17. Morphological characteristics of Street Workout practitioners.

    PubMed

    Sanchez-Martinez, Javier; Plaza, Paula; Araneda, Alberto; Sánchez, Patricio; Almagiâ, Atilio

    2017-02-01

    The determination of the morphological characteristics of the most popular sports has allowed the evaluation and comparison between athletes, which has helped to improve their performance. The Street Workout is an emerging sport based on calisthenics, which recently has become popular. Despite its popularization, neither the morphologic profile nor the morphologic characteristics of Street Workout athletes has been determined. Determine the profile and morphological characteristics of Street-Workout athletes, through anthropometry. Fourteen athletes (22.7 ± 3.26 years) were recruited from the National Calisthenics Tournament 2015 in Chile. The athletes were evaluated following the protocol of the International Society for the Advancement of Kinanthropometry to determine the somatotype, body composition, as well as indices of body composition such as body mass index, waist to hip ratio, waist to height ratio, fat/muscle mass and muscle/bone mass indexes. Street Workout practitioners presented a balanced-mesomorphic somatotype, a low fat mass and a high muscular development, with upper arms and trunk predominance. Regarding body composition indices, the values obtained allow us to classify them as a low-risk population of chronic non-communicable diseases. The present study sets a first antecedent of the morphological characteristics of Street Workout, determining that the Street Workout athletes presented balanced-mesomorphic somatotype and were classified as a healthy and athletic sample by their body composition indexes.

  18. Low-flow characteristics of Florida streams

    USGS Publications Warehouse

    Rumenik, R.P.

    1996-01-01

    Knowledge of the low-flow characteristics of Florida streams and rivers is essential in planning for the availability of adequate quantities of water for commercial- and public-water supply, agricultural irrigation, artificial recharge, and the dilution of waste discharge. This report provides low-flow characteristics for 216 continuous-record gaging stations using frequency analysis techniques. Included are low-flow frequency characteristics for 143 unregulated, gaging stations; and sample percentiles for 32 stations that were subject to regulation or diversion, and sample percentiles for 41 stations, regulated and unregulated, that exhibited significant trends in the annual low-flow time series. Estimates of low-flow frequency characteristics are provided for 242 partial-record stations and miscellaneous sites based on correlations with daily mean discharges at continuous-record stations. Low-flow measurement data are available at approximately 1,300 continuous-record gaging stations, partial- record stations and miscellaneous sites. Historic low-flow measurement data are accessible through the U.S. Geological Survey Automatic Data Processing System.

  19. CHARACTERISTICS OF COLLODION MEMBRANES FOR ULTRAFILTRATION

    PubMed Central

    Bugher, John C.

    1953-01-01

    An apparatus for the production of graded collodion membranes is described. The theoretical considerations of calibration are discussed in relation to the demonstrable structure and statistical characteristics of the membranes. A new definition of an "end-point" is suggested. PMID:13022936

  20. Motorcycle-related spinal injury: crash characteristics.

    PubMed

    Zulkipli, Zarir Hafiz; Abdul Rahmat, Abdul Manap; Mohd Faudzi, Siti Atiqah; Paiman, Noor Faradila; Wong, Shaw Voon; Hassan, Ahamedali

    2012-11-01

    This study presents an analysis of crash characteristics of motorcyclists who sustained spinal injuries in motorcycle crashes. The aim of the study is to identify the salient crash characteristics that would help explain spinal injury risks for motorcyclists. Data were retrospectively collected from police case reports that were archived at MIROS from year 2005 to 2007. The data were categorized into two subcategories; the first group was motorcycle crashes with spinal injury (case) and the second group was motorcycle crashes without spinal injury (control). A total of 363 motorcyclists with spinal injury and 873 motorcyclists without spinal injury were identified and analyzed. Descriptive analysis and multivariate analysis were performed in order to determine the odds of each characteristic in contributing to spinal injury. Single vehicle crash, collision with fixed objects and crash configuration were found to have significant influence on motorcyclists in sustaining spinal injury (p<0.05). Although relatively few than other impact configurations, the rear-end impacted motorcyclist shows the highest risk of spinal injury. Helmets have helped to reduce head injury but they did not seem to offer corresponding protection for the spine in the study. With a growing number of young motorcyclists, further efforts are needed to find effective measures to help reduce the crash incidents and severity of spinal injury. In sum, the study provides some insights on some vital crash characteristics associated with spinal injury that can be further investigated to determine the appropriate counter-measures and prevention strategies to reduce spinal injury.

  1. Explosion and detonation characteristics of dimethyl ether.

    PubMed

    Mogi, Toshio; Horiguchi, Sadashige

    2009-05-15

    In this study, the explosion and detonation characteristics of dimethyl ether (DME) were experimentally investigated. A spherical pressure vessel with an internal volume of 180L was used as the explosion vessel. Therefore, tubes 10m in length with internal diameters of 25mm and 50mm were used as detonation tubes. In addition, we compared the characteristics of DME with those of propane since DME is considered as a substitute fuel for liquid petroleum gas (LPG). At room temperature and atmospheric pressure, the maximum explosive pressure increased tenfold. The explosion index (K(G) values), an indicator of the intensity of an explosion, was larger than that of propane, indicating that the explosion was intense. No experimental study has been conducted on the detonation behavior of DME so far, but this research confirmed a transition to detonation. The detonation characteristics were similar to the characteristics of the Chapman-Jouguet detonation, and the concentration range for detonation was from 5.5% to 9.0%.

  2. Superconducting wire with improved strain characteristics

    DOEpatents

    Luhman, Thomas; Klamut, Carl J.; Suenaga, Masaki; Welch, David

    1982-01-01

    A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improve the strain characteristics of the wire.

  3. Superconducting wire with improved strain characteristics

    DOEpatents

    Luhman, Thomas; Klamut, Carl J.; Suenaga, Masaki; Welch, David

    1982-01-01

    A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improves the strain characteristics of the wire.

  4. Superconducting wire with improved strain characteristics

    DOEpatents

    Luhman, T.; Klamut, C.J.; Suenaga, M.; Welch, D.

    1979-12-19

    A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improve the strain characteristics of the wire.

  5. Personality Characteristics of Children of Alcoholics.

    ERIC Educational Resources Information Center

    Berkowitz, Alan; Perkins, H. Wesley

    1988-01-01

    Compared the personality characteristics of late adolescent and young adult children of alcoholics (COAs) with those of their peers, examining gender specificity in personality differences. COA respondents, particularly women, and especially women with alcoholic fathers, were more likely to report greater self-depreciation. Male COAs rated…

  6. School-Related Characteristics of Male Juveniles.

    ERIC Educational Resources Information Center

    Sapp, Gary L.; Abbott, Gypsy A.

    School-related characteristics of 256 male juveniles under the jurisdiction of a Family Court system were examined by perusing court records and conducting individual interviews with the juveniles. Results indicated that most juveniles last attended eighth grade, more than 81% had failed at least once, and more than half had fought frequently at…

  7. Flame characteristics for fires in southern fuels

    Treesearch

    Ralph M. Nelson

    1980-01-01

    A flame model and analytical method are used to derive forest fire flame characteristics. Approximate solutions are used to express flame lengths, angles, heights, and tip velocities of headfires and calm-air fires in terms of fire intensity. Equations are compared with data from low-intensity controlled burns in southern fuels and with data from the literature.

  8. Probe measures characteristics of hot gas stream

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Shielded, tubular flow calorimeter operated by valve position measures characteristics of a hot gas stream of unknown composition. Measurements of mass flow density and total heat content per unit mass, total heat content per unit mass only, and pitot pressure are made.

  9. 14 CFR 25.203 - Stall characteristics.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Stall characteristics. 25.203 Section 25.203 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... promptly prevent stalling and to recover from a stall by normal use of the controls. (b) For level...

  10. An Investigation of Double Bass Vibrato Characteristics

    ERIC Educational Resources Information Center

    Mick, James

    2015-01-01

    The purpose of this study was to investigate and describe various vibrato characteristics of university double bass students. The primary objectives were: (1) to describe vibrato rate and width for commonly used fingers in first, fourth, and thumb positions; (2) to investigate whether students initiate vibrato in an upward or downward direction;…

  11. Circular polarisation characteristics of stacked microstrip antennas

    NASA Astrophysics Data System (ADS)

    Lee, R. Q.; Talty, T.; Lee, K. F.

    1990-12-01

    Experimental results on the circular polarization (CP) characteristics of a two-layer electromagnetically coupled (EMCP) antenna are presented. Compared to the single CP patch antenna, the two-layer EMCP antenna with proper spacings can provide better axial ratio and directivity.

  12. Ultrasound characteristics of wood fracture surfaces

    Treesearch

    W.A. Côté; R.B. Hanna

    1983-01-01

    This study concentrated on the ultrastructural characteristics of hardwood ftacture surfaces, but it included southern yellow pine as a representative softwood for comparison. Very small specimens were made, tested for impression parallel to the grain, tension parallel to the grain, shear in the radial plane and shear in the tangential plane, and were then prepared for...

  13. Product Characteristics and Internet Shopping Intentions.

    ERIC Educational Resources Information Center

    Vijayasarathy, Leo R.

    2002-01-01

    Discussion of electronic commerce and online marketing focuses on an empirical study that investigated differences between Internet shopping intentions for products categorized by cost and tangibility. Highlights include hypotheses; respondent characteristics; results that showed that intentions to shop using the Internet differ by tangibility of…

  14. Near surface characteristics of foehn winds

    NASA Astrophysics Data System (ADS)

    Stiperski, Ivana

    2015-04-01

    Downslope windstorms occur commonly in mountainous regions around the world. Their importance is particularly great for air traffic, as well as wind energy, air pollution but also for ice shelf stability in the Antarctica, or deep water formation of the mountainous coasts. In this work we will focus on the foehn type of downslope windstorms and examine it's near surface turbulence characteristics in the Inn Valley, Austria. The foehn in the Inn Valley has been extensively studied throughout the past century, especially in several intensive campaigns. However, the smaller scale turbulence characteristics have only received limited attention. Here we present results from foehn episodes spanning over a year of data. The turbulence measurements at 5 stations within the Inn Valley, Austria as part of the i-Box project are used for the analysis. The general near surface turbulence characteristics of these events are examined and the characteristic scales of dominant transport are determined. Their dependence to horizontal heterogeneity is investigated both on the mesoscale and sub-mesoscale. Special focus is places on the question of energy balance closure during foehn episodes and the influence of advection.

  15. Thermochemical characteristics of chitosan-polylactide copolymers

    NASA Astrophysics Data System (ADS)

    Goruynova, P. E.; Larina, V. N.; Smirnova, N. N.; Tsverova, N. E.; Smirnova, L. A.

    2016-05-01

    The energies of combustion of chitosan and its block-copolymers with different polylactide contents are determined in a static bomb calorimeter. Standard enthalpies of combustion and formation are calculated for these substances. The dependences of the thermochemical characteristics on block-copolymer composition are determined and discussed.

  16. Relational Support and Person Characteristics in Adolescence.

    ERIC Educational Resources Information Center

    van Aken, Marcel A. G.; van Lieshout, Cornelis F. M.; Scholte, Ron H. J.; Branje, Susan J. T.

    1999-01-01

    Presents an heuristic model of the personality characteristics of adolescents and the supportive dimensions of interactions, relationships, and groups. The results of several empirical studies are presented to illustrate the model. Together, these studies present a transactional picture of the personality of adolescents and their relationships in…

  17. Characteristics of Inclusive Classrooms in Turkey

    ERIC Educational Resources Information Center

    Melekoglu, Macid Ayhan

    2014-01-01

    In this paper, inclusive classrooms in Turkey are described in terms of the characteristics of both classroom teachers and students with special needs. Participants of this study consisted of 54 teachers working in inclusive classrooms and 54 students with mild intellectual disabilities in those classrooms in Turkey. Data for this study were…

  18. Characteristics and Attitudes of Media Services Administrators.

    ERIC Educational Resources Information Center

    Johnson, Larry

    1996-01-01

    Media services department administrators at 161 public, four-year colleges and universities were surveyed regarding: characteristics of media directors, job assignments, academic preparation, work experience, participation in professional activities, time spent in job functions, and the effect of recent changes in departments. Compares results…

  19. 14 CFR 23.239 - Spray characteristics.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Spray characteristics. 23.239 Section 23.239 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... the pilots or damage the propellers or other parts of a seaplane or amphibian at any time during...

  20. 14 CFR 23.239 - Spray characteristics.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Spray characteristics. 23.239 Section 23.239 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... the pilots or damage the propellers or other parts of a seaplane or amphibian at any time during...