Tail Size Research Articles

DNA damage Evaluation in a Nursing Team Occupationally Exposed to Ionizing Radiation

Purpose : To evaluate DNA damage in lymphocytes and cognitive deficits in a nursing team occupationally exposed to ionizing radiation in a university hospital in southern Brazil. Method : Cross-sectional study, case-control design, included 79 women working in a nursing team in Hemodynamics, Radiology, Ambulatory and Midwifery Units. They were classified in two groups: 1_Exposed to ionizing radiation, n=38 (Hemodynamics and Radiology Units) and 2_Unexposed to ionizing radiation, n=41 (Ambulatory and Midwifery Unit). Blood was collected and DNA damage in lymphocytes was analyzed using the comet assay and micronucleus test (MN). The cells were classified according to the damage frequency (DF) and index (DI) based on the comet tail size. Cognition was also evaluated according to the scores obtained in Stroop test, the digit and word span. Results : No difference was found for the variables DI, DF, MN, Stroop_word, Stroop_color, Stroop_color/word between the groups. However, when the groups were analyzed independently of their exposure condition, the damage index in the Hemodynamics was lower than in all other Units. The damage frequency in Midwifery Unit was higher than in Ambulatory and Hemodynamics. The frequency of micronucleus was not different among the employees from the four Units. Conclusions : DNA damage in lymphocytes did not differ between nursing teams occupationally exposed or not exposed to ionizing radiation. However, higher damage in a non exposed group may indicate other risks to the healthcare team.

Range extension and natural history observations of a rare Panamanian snake, Geophis bellus Myers, 2003 (Colubridae: Dipsadinae)

The fossorial snake Geophis bellus is a small Panamanian endemic previously known only from the holotype. Here we report additional specimens, which greatly expand the known range of the species ca. 200 km from the type locality into western Panama. Furthermore, we provide information on sexual dimorphism in some scalation counts and in body and tail size. Finally, we provide information on natural history, including activity period, habitat usage, and reproductive cycle. Such discoveries are important for the development of conservation plans for this species in Panamá.

Lateral caudal axial pattern flap in 13 dogs.

To describe the frequency and extent of complications associated with lateral caudal axial pattern flaps used to cover large traumatic or excision skin defects on the dorsum, gluteal, and perineal region in 13 dogs. Case series. Thirteen client-owned dogs. Medical records from 8 institutions were reviewed for dogs treated with a lateral caudal axial pattern flap, including cases in which the procedure was combined with other reconstructive techniques. The flap length relative to the tail length, location of tail skin incision, size and cause of the defect, and short- and long-term complications were recorded. Thirteen dogs were included, 11 with tumors and 2 with traumatic skin loss. The mean estimated length of the flap relative to tail length was 51% (range 33-70%). Four dogs had wound complications. This included 2 dogs with minor postoperative wound complications (mild distal dehiscence) that did not require surgical revision and 2 dogs with major complications that required surgical revision. Two of these 4 dogs had distal flap necrosis, one was revised surgically and one was managed conservatively. In these 2 dogs, the flap length was estimated as 80% and 65% of the tail length, respectively. At 30 days, flaps in all dogs were completely healed. No long-term complications were recorded in any dog. For some dogs, the reconstruction was not obvious, with only the change in hair direction and color noticeable. Lateral caudal axial pattern flap is a reconstructive option for gluteal, dorsal, and perineal skin defects in dogs. Distal flap necrosis and dehiscence due to wound infection occurred in 4 dogs that required additional wound care but not always surgical revision.

Evaluation of drug toxicity profiles based on the phenotypes of ascidian Ciona intestinalis

In vivo toxicity evaluation using model organisms is an important step for the development of new drugs. Here, we report that Ciona intestinalis, a chordate invertebrate, is beneficial to drug toxicity evaluation for the following reasons: rapid embryonic and larval development, resemblance to vertebrates, ease of management, low cost, transparent body, and low risk of ethical issues. The dynamic phenotypic change of Ciona larvae during metamorphosis prompted us to examine the effect of cytotoxic drugs on its development by quantifying six toxicity endpoints: degenerated tail size, ampulla length, rotation of body axis, stomach size, heart rate, and body size. As a result, mitochondrial respiratory inhibitors, tubulin polymerization/depolymerization inhibitors, or DNA/RNA synthesis inhibitors showed distinct toxicity profiles against these six endpoints, but drugs with the same targets showed a similar toxicity profile in Ciona. Our results suggest Ciona is an effective animal model for profiling drug toxicity and exploring the mechanisms of drugs with unknown targets.

Densities, viscosities and derived thermophysical properties of water-saturated imidazolium-based ionic liquids

In order to evaluate the impact of the alkyl side chain length and symmetry of the cation on the thermophysical properties of water-saturated ionic liquids (ILs), densities and viscosities as a function of temperature were measured at atmospheric pressure and in the (298.15–363.15)K temperature range, for systems containing two series of bis(trifluoromethylsulfonyl)imide-based compounds: the symmetric [CnCnim][NTf2] (with n=1–8 and 10) and asymmetric [CnC1im][NTf2] (with n=2–5, 7, 9 and 11) ILs. For water-saturated ILs, the density decreases with the increase of the alkyl side chain length while the viscosity increases with the size of the aliphatic tails. The saturation water solubility in each IL was further estimated with a reasonable agreement based on the densities of water-saturated ILs, further confirming that, for the ILs investigated, the volumetric mixing properties of ILs and water follow a near ideal behavior. The water-saturated symmetric ILs generally present lower densities and viscosities than their asymmetric counterparts. From the experimental data, the isobaric thermal expansion coefficient and energy barrier were also estimated. A close correlation between the difference in the energy barrier values between the water-saturated and pure ILs and the water content in each IL was found, supporting that the decrease in the viscosity of ILs in presence of water is directly related with the decrease of the energy barrier.

Morphometry of boar sperm head and flagellum in semen backflow after insemination

Once deposited in the female reproductive system, sperm begin their competition and undergo a selection to reach the site of fertilization. Little is known about the special characteristics of sperm that reach the oviduct and are able to fertilize, with even less information on the role of sperm dimension and shape in transport and fertilization. Here, we examine whether sperm morphometry could be involved in their journey within the uterus. For this purpose, sperm head dimension (length, width, area, and perimeter) and shape (shape factor, ellipticity, elongation, and regularity), and flagellum length were analyzed in the backflow at different times after insemination (0–15, 16–30, and 31–60 minutes). Sperm morphometry in the backflow was also analyzed taking into account the site of semen deposition (cervical vs. intrauterine). Finally, flagellum length was measured at the uterotubal junction. Sperm analyzed in the backflow were small (head and flagellum) with different head shapes compared with sperm observed in the dose before insemination. The site of deposition influenced head morphometry and tail size both being smaller in the backflow after cervical insemination compared with intrauterine insemination. Mean tail length of sperm collected in the backflow was smaller than that in the insemination dose and at the uterotubal junction. Overall, our results suggest that sperm size may be involved in sperm transport either because of environment or through sperm selection and competence on their way to encounter the female gamete.

The influence of experimental parameters and specimen geometry on the mass spectra of copper during pulsed-laser atom-probe tomography.

We have studied the influence of experimental factors and specimen geometry on the quality of the mass spectra in copper (Cu) during pulsed-laser atom-probe tomography. We have evaluated the effects of laser pulse energy, laser pulse frequency, specimen base temperature, specimen tip radius, and specimen tip shank half-angle on the effects of mass resolving power, (m/Δm), at full-width at half-maximum and at full-width at tenth-maximum, the tail size after the major mass-to-charge state (m/n) ratio peaks, and the mass spectra. Our results indicate that mass resolving power improves with decreasing pulse energy between 40 and 80 pJ and decreasing base temperature between 20 and 80 K. The mass resolving power also improves with increasing tip radius and shank half-angle. A pulse frequency of 250 kHz slightly improves the mass resolving power relative to 100 or 500 kHz. The tail size decreases with increasing pulse energy. The mass resolving power improves when the cooling time is reduced, which is influenced by the thermal diffusivity of Cu and the specimen base temperature.

The relationship between language proficiency and attentional control in Cantonese-English bilingual children: evidence from Simon, Simon switching, and working memory tasks.

By administering Simon, Simon switching, and operation-span working memory tasks to Cantonese-English bilingual children who varied in their first-language (L1, Cantonese) and second-language (L2, English) proficiencies, as quantified by standardized vocabulary test performance, the current study examined the effects of L1 and L2 proficiency on attentional control performance. Apart from mean performance, we conducted ex-Gaussian analyses to capture the modal and positive-tail components of participants' reaction time distributions in the Simon and Simon switching tasks. Bilinguals' L2 proficiency was associated with higher scores in the operation span task, and a shift of reaction time distributions in incongruent trials, relative to congruent trials (Simon effect in μ), and the tail size of reaction time distributions (τ) regardless of trial types in the Simon task. Bilinguals' L1 proficiency, which was strongly associated with participants' age, showed similar results, except that it was not associated with the Simon effect in μ. In contrast, neither bilinguals' L1 nor L2 proficiency modulated the global switch cost or local switch cost in the Simon switching task. After taking into account potential cognitive maturation by partialling out the participants' age, only (a) scores in the working memory task and (b) RT in incongruent trials and (c) Simon effect in μ in the Simon task could still be predicted by bilinguals' L2 proficiency. Overall, the current findings suggest that bilingual children's L2 proficiency was associated with their conflict resolution and working memory capacity, but not goal maintenance or task-set switching, when they performed the cognitive tasks that demanded attentional control. This was not entirely consistent with the findings of college-age bilinguals reported in previous studies.

Thermophysical properties of sulfonium- and ammonium-based ionic liquids

Experimental data for the density, viscosity, refractive index, and surface tension of four sulfonium- and ammonium-based ionic liquids (ILs) with the common bis(trifluoromethylsulfonyl)imide anion were measured in the temperature range between 288.15 and 353.15K and at atmospheric pressure. The ILs considered include butyltrimethylammonium bis(trifluoromethylsulfonyl)imide, [N4111][NTf2], tributylmethylammonium bis(trifluoromethylsulfonyl)imide, [N4441][NTf2], diethylmethylsulfonium bis(trifluoromethylsulfonyl)imide, [S221][NTf2], and triethylsulfonium bis(trifluoromethylsulfonyl)imide, [S222][NTf2]. Based on the gathered results and on data taken from literature, the impact of the cation isomerism and of the size of the aliphatic tails, as well as the effect resulting from the substitution of a nitrogen by a sulfur atom as the cation central atom, on the thermophysical properties of sulfonium- and ammonium-based ILs is discussed here. Remarkably, more symmetric cations present a lower viscosity for the same, and sometimes even for higher, alkyl chain lengths at the cation. Additional derivative properties, such as the isobaric thermal expansion coefficient, the surface thermodynamic properties and the critical temperature for the investigated ILs were also estimated and are presented and discussed.

Low Critical Micelle Concentration Discrepancy between Theory and Experiment.

Experimental measurements for a variety of surfactants unexpectedly show that the critical micelle concentration (CMC) becomes constant with respect to increasing the size of the hydrophobic tail. This observation disagrees with theoretical models where it is expected to continue to decrease exponentially. Because of the lack of a satisfactory explanation for such a discrepancy from theory, we have studied these systems using a coarse-grained model within the single-chain mean field (SCMF) theory combined with relevant micellar kinetic effects. In particular, a microscopic model for poly(ethylene oxide) alkyl ether was applied to describe a series of nonionic gemini surfactants. When kinetic effects are used to correct the equilibrium CMC values from the SCMF scheme together with the loss of surfactants due to adsorption on the experimental recipient, it is possible to reproduce the correct order of magnitude of the experimental CMC results. Hence it appears that the experimental values disagree with the theoretical predictions because they are not true equilibrium values due to the fact that the time scales for these low CMC values become astronomically large.

Research on Online Detection of Steel Plate Head and Tail Shape

This paper aims to research the on-line measurement of the steel plate head and tail shape, and to measure the steel head and tail geometry size by using digital image processing and computer vision technology. The image gathered from high precision CCD camera is segmented with using the method based on the improved local binary fitting (LBF) model. The head and tail shape and size of steel plate is accurately measured, which provides the basis data for the follow-up steel rolling and shearing process.

电磁发射枢轨界面初始接触状态研究

Sliding interface status during whole electromagnetic rail launch process depends on contact status after initial assembly in which initial contact force between armature and rails(A-R) is provided by trailing arm elastic deformation in the C-armature rail launcher, which influences launcher system efficiency and rail lifespan. This paper focuses on the contact status of initial C-armature assembly of rail launcher with constructing the contact model for simulating computation and designing many groups of experiments for contrast testing. Considering safe deformable limits of armature material, variation laws of contact pressure, contact region(area) and contact force are analyzed under conditions of small-range feasible heads and tail sizes. Interferential proportion is proposed as a contact status dependent key parameter. Contact region transformed from tail to head of trailing arm as interferential proportion increasing, maximum of contact area is about half of whole outer surface of trailing arm. Optimal contact status for favorable electric contact and engineering implement technique are also discussed.

Cell damage induced by copper: An explant model to study anemone cells

Sea anemones are benthic organisms, of low mobility and can be directly affected by water pollution. This work studied the defense mechanisms and DNA damage caused by copper toxicity in cells from the anemone Bunodosoma cangicum. For this, exposure of anemones cells were held, kept in primary culture through explant of podal disk to copper (7.8 and 15.6μg/L), and the control group, for 6 and 24h. Cytotoxicity was seen through the viability and cell number, MXR phenotype through the accumulation of rhodamine-B, ROS generation by H2DCF-DA and DNA damage by comet assay. The results obtained show that there is a drop in viability and number of cells, especially after exposure of 24h in 15.6μg/L. There is an induction of the MXR activity only at 7.8μg/L for 24h. As for ROS, there is an increase in the generation of reactive species in greatest concentration of copper for 6h, and in both for 24h, which leads to oxidative stress, which culminates with a DNA damage. What was evidenced by the increase of the tail size, % DNA presented and moment of tail. Therefore, the copper represents an adversity to the anemones cells, being cytotoxic and genotoxic.

Tail Autotomy, Tail Size, and Locomotor Performance in Lizards

The effect of tail autotomy on locomotor performance has been studied in a number of lizard species. Most of these studies (65%) show that tail autotomy has a negative effect on sprint speed, some studies (26%) show no effect of autotomy on sprint speed, and a few (9%) show a positive effect of autotomy on sprint speed. A variety of hypotheses have been proposed to explain the variation across these studies, but none has been tested. We synthesize these data using meta-analysis and then test whether any of four variables explain the variation in how tail autotomy impacts sprint speed: (1) differences in methodology in previous studies, (2) phylogeny, (3) relative tail size, and (4) habitat use. We find little evidence that methodology or habitat use influences how sprint speed changes following tail autotomy. Although the sampling is phylogenetically sparse, phylogeny appears to play a role, with skinks and iguanids showing fairly consistent decreases in speeds after autotomy and with lacertids and geckos showing large variation in how autotomy impacts speed. After removing two outlying species with unusually large and long tails (Takydromus sp.), we find a positive relationship between relative tail size and sprint speed change after autotomy. Lizards with larger tails exhibit a greater change in speed after tail loss. This finding suggests that future studies of tail autotomy and locomotor performance might profitably incorporate variation in tail size and that species-specific responses to autotomy need to be considered.

Do local or global risk factors explain the size, value and momentum trading pay-offs on the Warsaw Stock Exchange?

This article shows that momentum trading fails to generate significant profits beyond the 1-month holding period on the Warsaw Stock Exchange over the years 2002–2011. Size and value strategies are efficacious but have varying magnitudes over time: size premium diminishes in the second subperiod. Domestic, European and global pricing model specifications are challenged with strategy pay-offs to test the rational explanation for the profitability of these investment styles. The performance of the buy side of size and value strategies is captured by the market risk exposure but both single- and multi-factor models leave significant alphas of large and value portfolios. Domestic models outperform their nondomestic specifications: European CAPM performs better than its global analogue while nondomestic three-factor models perform similarly. Tail size and value portfolios are characterized by negative but mostly insignificant loadings on European and global nonmarket risk factors that emerge from the negative ...

고고도 장기체공 전기 동력 무인기의 꼬리 날개 설계

KARI is developing a solar-electric powered HALE UAV(EAV-3). For demonstrating the technology, EAV-2H, a down-scaled version of EAV-3, is developed and after EAV-2H’s initial flight test, the directional stability and control need to be improved. Thus, the vertical tail and rudder of EAV-2H are redesigned with Advanced Aircraft Analysis(AAA). Size of the rudder is increased from mean chord ratio of rudder to vertical tail, C r /C v (%)=30 to C r /C v (%)=60 and size of the vertical tail is reduced 15%. As a result, the directional control to side wind(ν₁) is improved to sideslip angle, β(νdeg)=25° and ν₁(m/sec)=3.54. Also, variation of airplane side force coefficient with sideslip angle(C yβ ) and variation of airplane side force coefficient with dimensionless rate of change of yaw rate (C yr ) are reduced 15% and 22%, respectively to minimize the effect of side wind. The empennage design of EAV-2H is verified with flight tests and applied to design of KARI’s solar-electric-powered EAV-3.

The Profi tability of Size, Value and Momentum Trading Strategies - Evidence from the Polish Stock Market

This paper shows that momentum trading fails to generate significant profits beyond the one-month holding period on the Warsaw Stock Exchange over the years 2002-2011. Size and value strategies are efficacious but have varying magnitudes over time: Size premium diminishes in the second subperiod. Domestic, European and global pricing model specifications are challenged with strategy payoffs to test the rational explanation for the profitability of these investment styles. The performance of the buy-side of size and value strategies is captured by the market risk exposure but both single- and multi-factor models leave significant alphas of large and value portfolios. Domestic models outperform their non-domestic specifications: European CAPM performs better than its global analogue while non-domestic three-factor models perform similarly. Tail size and value portfolios are characterised by negative but mostly insignificant loadings on European and global non-market risk factors that emerge from the negative relationship between Polish, European and global currency-adjusted SMB and HML. It is further shown that after adjustment for fluctuations between USD and PLN the magnitude and correlation structure between local and global risk factors change significantly.

Equivalence of chain conformations in the surface region of a polymer melt and a single Gaussian chain under critical conditions

In the melt polymer conformations are nearly ideal according to Flory's ideality hypothesis. Silberberg generalized this statement for chains in the interfacial region. We check the Silberberg argument by analyzing the conformations of a probe chain end-grafted at a solid surface in a sea of floating free chains of concentration φ by the self-consistent field (SCF) method. Apart from the grafting, probe chain and floating chains are identical. Most of the results were obtained for a standard SCF model with freely jointed chains on a six-choice lattice, where immediate step reversals are allowed. A few data were generated for a five-choice lattice, where such step reversals are forbidden. These coarse-grained models describe the equilibrium properties of flexible atactic polymer chains at the scale of the segment length. The concentration was varied over the whole range from φ = 0 (single grafted chain) to φ = 1 (probe chain in the melt). The number of contacts with the surface, average height of the free end and its dispersion, average loop and train length, tail size distribution, end-point and overall segment distributions were calculated for a grafted probe chain as a function of φ, for several chain lengths and substrate∕polymer interactions, which were varied from strong repulsion to strong adsorption. The computations show that the conformations of the probe chain in the melt do not depend on substrate∕polymer interactions and are very similar to the conformations of a single end-grafted chain under critical conditions, and can thus be described analytically. When the substrate∕polymer interaction is fixed at the value corresponding to critical conditions, all equilibrium properties of a probe chain are independent of φ, over the whole range from a dilute solution to the melt. We believe that the conformations of all flexible chains in the surface region of the melt are close to those of an appropriate single chain in critical conditions, provided that one end of the single chain is fixed at the same point as a chain in the melt.

Detection of cold chain abuse in frozen and chilled salmon using the comet assay

DNA damage in frozen and chilled salmon (Salmo salar) was investigated using the comet assay. Frozen salmon was thawed at 10 °C and chilled salmon was kept in flake ice, mimicking a thermal abuse and an extended storage, respectively. Electrophoresis conditions were as follows: a second layer of low-melting-point agarose at 1 g/100 mL; a voltage of 2.5 V cm−1; and running time of 1.0 min. Control cells showed relatively round shaped comets with a large and intense head, and a short tail. Their olive tail moment (OTM) profiles showed a predominance of low values that were narrowly distributed (between 8 and 25). As thawing or chill storage progressed, comets showed an increase in tail size, a shift of intensity from the head to the tail and a clear separation between the two. This was associated with a shift of OTMs toward higher values and a wider distribution of these values: between 17 and 43 after 42 h of thawing; and between 12 and 46 after 12 days of chill storage. Based on OTM values and their distribution, the DNA damage in salmon cells was visible for frozen salmon after 3 h of thawing at 10 °C and for chilled salmon after 9 days of storage.

Applying generalized linear models as an explanatory tool of sex steroids, thyroid hormones and their relationships with environmental and physiologic factors in immature East Pacific green sea turtles (Chelonia mydas)

Generalized linear models were fitted to evaluate the relationship between 17β-estradiol (E2), testosterone (T) and thyroxine (T4) levels in immature East Pacific green sea turtles (Chelonia mydas) and their body condition, size, mass, blood biochemistry parameters, handling time, year, season and site of capture. According to external (tail size) and morphological (<77.3 straight carapace length) characteristics, 95% of the individuals were juveniles. Hormone levels, assessed on sea turtles subjected to a capture stress protocol, were <34.7nmolTL−1, <532.3pmolE2 L−1 and <43.8nmolT4L−1. The statistical model explained biologically plausible metabolic relationships between hormone concentrations and blood biochemistry parameters (e.g. glucose, cholesterol) and the potential effect of environmental variables (season and study site). The variables handling time and year did not contribute significantly to explain hormone levels. Differences in sex steroids between season and study sites found by the models coincided with specific nutritional, physiological and body condition differences related to the specific habitat conditions. The models correctly predicted the median levels of the measured hormones in green sea turtles, which confirms the fitted model's utility. It is suggested that quantitative predictions could be possible when the model is tested with additional data.