bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of Radio Wave Velocities in the Firn Zones of Polar Ice Sheets (Abstract only)
Authors: Shabtaie Sion , Bentley Charles R.
Published: September 2017

A common-reflection point profiling experiment to obtain electromagnetic wave velocities in the ice at Dome C at 35 MHz was carried out to a maximum antenna separation of 2 km. Four different recording systems were used for this experiment. The echoes from numerous internal reflecting horizons within the ice and the bedrock were recorded in four different ways: in A-display form on film using an oscilloscope, in intensity-modulated form using the Honeywell Visi-corder and thermal intensifier on heat-sensitive silver paper, and in both raw and signal-averaged form on magnetic tape.

Travel times of oblique reflections from nearly 160 internal layers down to a depth of 2 600 m and reflections from the ice bottom were measured at each station along the profile. The average wave velocities from the surface of each internal layer were measured to obtain a continuous mean velocity vs depth profile.

Velocity-density models derived from the dielectric mixture equations of Looyenga, Böttcher, Lichtenrecker, Hanai-Bruggeman and Wiener were compared against the measurements. In addition Robin's empirical relationship was also used in this study. The preliminary results show that the observed velocity depth profile for the ice column is compatible with Wiener's equation (with Formzahl = 0) and a newly derived empirical relationship (from this study) of where γi is ice density, γf firn density, ε dielectric constant of mixture, and εi dielectric constant of ice; γf>0.55 kg m−3. It appears that the electromagnetic wave velocity in the firn is 20 m MS−1 or more, which is higher than previously assumed.

The above models were also compared with velocity measurements in the Devon Island bore holes (Robin 1975) and at several sites on the Ross Ice Shelf where the ice is relatively thin compared to Dome C so that the effect of firn on mean velocities is more pronounced. The results for these sites suggest again that Wiener's equation and empirical relationship from this study produce velocities compatible with the observed values.
Energy Balance at the Surface of the Ice Sheet in the Coastal Area of Adélie Land, Antarctica (Abstract only)
Authors: Blaix P.-L , Delaunay D , Poggi A
Published: September 2017

Hourly measurements of wind, temperature, and humidity were made between elevations of 1 and 20 m in the coastal area of Adélie Land over a period of 45 d in January and February 1978. About 1000 profiles are available.

The height of the constant flux layer is >5 m despite the influence of katabatic winds, the wind profile is logarithmic with a mean standard deviation from the logarithmic law of 15 mm s−1. The potential temperature profile is also logarithmic with a mean standard deviation of 0.04°C. The most important deviation from the logarithmic law appears between -4 and 0°C.

Humidity was measured at two points only, between 1 and 20 m; the mean gradient was about 0.01 mbar m−1 and the flux of latent heat was generally negligible.

Net radiation was measured for only 10 d because of radiometer failure. All the fluxes are calculated using data for the 5 m layer. For the 10 d period, the heat loss was about 3 Wm−2 with a mean heat flux of -27.5 Wm−2 and mean net radiation of -10.5 Wm−2(the minus sign signifying the flux is towards the surface). In general, the heat flux is towards the surface (92% of the cases) but is away from the surface in the afternoon. The ablation during the 10 d period without snow-fall was about 200 mm of ice.
The Importance of Pressurized Subglacial Water in Separation and Sliding at the Glacier Bed (Abstract only)
Authors: Bindschadler Robert
Published: September 2017

The effect of pressurized sub-glacial water on the sliding process is quantified by calculating a “bed separation index”. The water pressure distribution i s calculated assuming the existence of a Rothlisberger channel at the bed. Kamb's formulation is used to describe the variation of normal stress over periodic bed undulations. The hypothesis is that as either basal shear stress or water pressure is increased the extent of ice-bedrock separation (on the down-glacier side of undulations) increases and enhanced sliding occurs

Data from three glaciers of widely varying size are used to test this hypothesis. For Columbia Glacier and “Ice Stream B” the importance of including the effects of water pressure in any “sliding law” are pronounced. More complete data from the third test case, Variegated Glacier, are used to compare a number of possible formulations of sliding law which encompass the above hypothesis. A modified Weertmantype law appears to be most preferable while while some possibilities, including Budd's lubrication factor hypothesis, are tentatively rejected.

Consideration of the temporal variations of the “bed separation index” reemphasize that, especially in the short time scale, variations of water pressure can dominate the sliding process. An order of magnitude increase in water discharge causes a hundred fold transient increase in the water pressure.

This paper has been accepted for publication in the Journal of Glaciology
A Time-Dependent Model of an Ice Dome-Ice Stream-Ice Shelf System: Preliminary Results (Abstract only)
Authors: Bindschadler Robert , Gore Robert
Published: September 2017

This model is designed to simulate the temporal response of an ice sheet along a flow line by accounting properly for the division of the driving stress Into basal-stress and longitudinal-stress gradient components. A vertical section along a central flow line is divided into both horizontal and vertical grid points. A self-consistent solution of stress and velocity is found for any specified geometry. The sliding velocity is determined from a relationship which includes the base stress and a prescribed sub glacial water pressure. In these experiments, the ice is assumed to be isothermal. For any given set of initial conditions and a specified mass-balance distribution, the model follows the temporal behavior of the flow line to a steady state. In later work, the water pressure will be calculated from the equilibrium pressure within RothHsberger conduits for the specific geometry and determined rate of meltwater production. The time-varying temperature field due to conductive and advectlve processes will be included in later versions of the model.
Photogrammetric Investigation of Byrd Glacier Surface Lowering (Abstract only)
Authors: Brecher Henry H.
Published: September 2017

While carrying out photogrammetric measurements to provide surface velocities and elevations for use in studies of the equilibrium and dynamics of Byrd Glacier, I noted that comparison of elevations obtained by ground surveys in 1978-79 with US Geological Survey topographic maps made from 1960-62 aerial photography indicated a very large apparent lowering of the glacier surface in this short timeinterval. The apparent lowering varied between 50 and 150 m along a 60 km section of the glacier for which data were available (Brecher 1980).

The ground measurements were estimated to be in error by no more than 3 in but the accuracy of elevations on the maps was unknown. Because these are reconnaissance maps, however, substantial errors would not be unexpected. It was therefore necessary to obtain more accurate glacier surface elevations for 1960–62 in order to determine whether the lowering is real. Photogrammetric strip triangulations of three individual strips of photography, two taken in November 1960 and the third in February 1963, which cover the region of the greatest apparent lowering, have now been completed. The old strips were oriented to fixed points on the two “banks” of the glacier derived for this purpose from the 1978–79 photogrammetric work, thus bringing the measurements from the old and new photography into a common coordinate system.

The glacier surface elevations for 1960–62 are the same as those obtained from the 1978–79 ground survey and photogrammetry. While it is difficult to give measures of accuracy of the results since no independent data are available for comparison, internal evidence indicates that precision higher than the expected 10 m has been achieved in the measurements. It can thus be stated unambiguously that no detectable surface lowering has occurred on any of the parts of the glacier which have been investigated.
Antarctic Anion Glaciochemistry (Abstract only)
Authors: Herron Michael M.
Published: September 2017

Snow and ice-core samples from a number of sites in Antarctica and Greenland have been analyzed for the major anions Cl−, NO3−, and SO42- by ion chromatography. Reproducibility on adjacent core or pit samples is ±10% at the 95% confidence level. Chloride is of marine origin except following some major volcanic eruptions. Chloride concentrations decrease exponentially with increasing site elevation with a scale height of about 1.5 km. For sites of comparable elevation, Antarctic Cl− concentrations are only slightly higher than in Greenland. Sulfate concentrations, corrected for the marine aerosol contribution, show an inverse dependence on snow accumulation rate. For sites of comparable accumulation rate, Greenland concentrations exceed those in Antarctica by a factor of 2 to 3. Nitrate concentrations also decrease with increasing accumulation rate and for comparable sites Greenland NO3− concentrations are a factor of 2 higher than in Antarctica. There is no evidence of solar modulation or supernova perturbation of Greenland NO3− concentrations. The Byrd deep core is shown to have distinct seasonal variations in Cl− and SO42- that may be used for dating. In addition, the Byrd core contains volcanic signals similar to those found in Greenland. Recent Greenland snow contains about 4 times as much SO42- and 2 to 3 times as much NO3− as is found in older ice due to modern fossil fuel combustion.
Calculation of Snow Avalanche Runout Distance
Authors: Bakkehoi S. , Domaas U. , Lied K.
Published: September 2017

Distance of maximum avalanche runout is calculated by four topographical factors. An empirical equation found by regression analysis of 206 avalanches is used to predict the maximum runout distance in terms of average gradient of the avalanche path (angle α). The correlation coefficient R = 0.92, and the standard deviation of the residuals SD = 2.3°.

The avalanche paths are further classified into different categories depending on confinement of the path, average inclination of the track 6, curvature of the path y", vertical displacement Y, and inclination of rupture zone Q. The degree of confinement is found to have no significant effect on the runout distance expressed by a. Best prediction of runout distance is found by a classification based on 5 and Y. For avalanches with β <30° and Y > 900 m, R = 0.90 and SD = 1.02°.

The population of avalanches is applied to a numerical/dynamical model presented by Perla and others (1980). Different values for the friction constants v and M/DY are computed, based on the observed extent of the avalanches. The computations are supplied by velocity measurements v from a test avalanche where Y = 1 000 m, and vmax = 60 m s−1. The best fitted values are μ = 0.25 and M/DY = 0.5, which gives R = 0.83 and SD = 3.5°.
A Comparison of Unsteady Wave Propagation for Various Snowpack Properties
Authors: Brown R. L.
Published: September 2017

The manner in which inelastic Shockwaves propagate through snow is evaluated. The volumetric material behavior of snow is represented as an inelastic rate sensitive relationship. The constitutive equation has incorporated into it such crystalline properties as grain size, bond length, bond radius, pore size, and average number of bonds per grain. As a consequence, this constitutive formulation can be used to describe how Shockwave behavior is affected by different physical properties. The governing equations, i.e. the momentum and continuity equations, are solved by integrating them to put these equations in terms of jumps in pressure, density, and particle velocity.

Results are obtained for a wide variety of snow properties. First, the effect of density is evaluated by considering densities ranging from 150 to 300 kg m−3. Then the effect of intergranular bonding is considered by varying the bond radius/grain radius ratio from 0.15 to 0.40. Finally, the Shockwave frequency is varied parametrically to determine the effect of these parameters on wave attenuation rates.

The results are then compared to experimental data. The theoretical results are shown to agree well with the test data. The degree of intergranular bonding was also found to have a very significant effect on attenuation rates.

Finally the importance of the air phase on the propagation of Shockwaves in snow is investigated. The governing equations for each phase are developed by using a mixture theory formulation. An order of magnitude analysis is made in order to assess the importance of the air phase on attenuation rates.
Time-Dependent Deformation Behaviour of Structures in Snow, Firn or Ice
Authors: Dörr Rudolf , Jessberger Hans L.
Published: September 2017

The time-dependent vertical deformation and the variation of the cross-section of the Georg von Neumayer wintering station, built during the Antarctic summer of 1980-81, are investigated with regard to the rheological behaviour of the surrounding snow, firn, and ice. Computations are performed to determine the time-dependent settlement using the compactive ( compressée) viscosity nc as the viscoelastic parameter, being a function of the density, nc is derived from the depth-density curve down to to 73.6 m depth, the initial density p0, and the accumulation rate. The ground plan and the foundation pressures of the station, and the weight of snow-fill and accumulation, are employed in the analysis, using actual values.

These computations are compared with measurements for a period of 320 d. The described measurement systems include the possibility of finding a reference level in the continuously compressed ice shelf. The time-dependent deformation of experimental tubes is also presented on the basis of convergency data taken over a period of 480 d.
Distribution of Snow Drifts on Ridge Slopes: Measurements and Theoretical Approximations
Authors: Föhn Paul M. B. , Meister Roland
Published: September 2017

During several winters the positions and magnitudes of excess snow deposits or denudation zones caused by wind have been evaluated on the flanks of regular, elongated mountain ridges. The surveys were carried out by conventional measurements of mass balance. According to angle of slope (10 to 35°), shape of crest (hump- or wedge-shaped) and orientation to the wind, various patterns of snow deposition may be found. It is shown that, on ridges oriented perpendicularly to the main wind direction (north-west) during snow storms, near-periodic snow deposits may be expected on the lee slope. On the windward side, there is a denudation zone near the crest. The measurements indicate that lee slopes, of mean slope angle, are buried in mid-winter under twice as much snow as the adjacent windward slopes. However, the ridge system as a whole accumulates the same amounts of snow as do areas of flat terrain. Theoretical approximations based on theories of potential flow and semi-empi rical plume models are used to simulate the presumed dispersion of snow. The model calculations, intended as diagnostic tools, suggest that snow may be diffused and deposited on lee slopes in a plume-like manner similar to other particulate matter. Snowfall, together with low-level blowing snow as an additional source of suspended particles, appears to increase the snow deposits, mainly on the foot of steeper ridges.
Measurements and Analyses of Velocity Profiles and Frazil Ice-Crystal Rise Velocities During Periods of Frazil-Ice Formation in Rivers
Authors: Gosink J. P. , Osterkamp T. E.
Published: September 2017

The vertical concentration distribution of frazil-ice crystals in a stream during the formation and growth of frazil ice was discussed in a preliminary way by Gosink and Osterkamp (1981). This paper extends and completes the analysis of buoyant rise velocities of frazil-ice crystals and applies the results to an interpretation of measured velocity profiles in rivers during frazil-ice events. Additional experimental data are also presented. Two time scales are defined: the buoyant time scale TB, which represents the time required for a frazil crystal to rise, buoyantly, from the river bottom to the water surface, and the diffusive tine scale TD, which represents the time required for a frazil crystal to he transported by turbulence through the depth. It is shown that the ratio of the time scales TB/TD defines the nature of the layering processes; in particular, if TB/TD<1, then buoyant forces Till lift a frazil crystal faster than turbulent diffusion can redistribute it and the flow will be layered. Conversely, if TB./TD>1, turbulent mixing will proceed faster than buoyant lifting and the flow will be well-mixed. This ratio, for frazil particles of diameter 2 mm or more, corresponds to rule-of-thumb velocity criteria developed in Norway and Canada to distinguish layered frazil-ice/water flow from well-mixed flow.

The development of this theory depends in large part upon the determination of TB, which depends upon the rise velocity of frazil-ice crystals. A force balance .nodel was developed for the rise velocity of a frazil crystal. Field observations during frazil -ice formation in Goldstream Creek and in the Chatanika River north of Fairbanks are reported, including a series of measurements of the rise velocities of frazil-ice crystals. Typical particle size of frazil ice was about 2 mm with a rise velocity of about 10.0 mm s -1. The agreement of measured rise velocities with the theoretical model is good considering uncertainties in the drag coefficient and in the determination of frazil crystal sizes under field conditions.

Velocity profiles in the Chatanika River and in Goldstream Creek during frazil formation suggest that the time-scale ratio may serve as a transition criterion between layered frazil-ice/water flow and well-mixed flow. This ratio was calculated with the rise velocity of frazil-ice crystals arbitrarily chosen to be 0.01 m s−1.
Comparison Between Different Yield Functions for Saline Ice
Authors: Häusler F. U.
Published: September 2017

Data obtained from tests of uniaxial and multi-axial compressive strength on saline ice have been used to determine the coefficients of the Smith yield function, which uses seven parameters, and of the Pariseau yield function, which uses five. Both functions describe orthotropic materials and have been reduced for transverse isotropy. The tests of compressive strength were carried out over the past few years in the ice laboratory of the Hamburgische Schiffbau-Versuchsanstalt (HSVA) on a closed-loop controlled triaxial loading frame with brush-type loading platens. The values for tensile strength have been obtained from data published by other researchers.

The ice-strength values computed by means of the two yield functions were compared with measured ice strengths; the seven-parameter Smith yield function provides reliable results over the whole stress space, while the simpler Pariseau yield function is only applicable within a restricted area of the stress space.
Icebergs: Their Physical Dimensions and the Presentation and Application of Measured Data
Authors: Hotzel I. Stuart , Miller John D.
Published: September 2017

A knowledge of the dimensional characteristics of icebergs off the east coast of Canada is required for both scientific and engineering purposes. To fulfil this need, hydrocarbon exploration in the region has been supported by a program aimed at collecting morphometric data on icebergs, in addition to providing operational support for activities such as ice-berg towing, this program has yielded information which will be useful for the engineering design of offshore structures. Functional relationships between the dimensions of icebergs are presented and ratios between the linear dimensions are examined. These ratios are used to calculate preliminary values for draft and mass on the Grand Banks and are demonstrated to give reasonable values for draft of icebergs off Greenland.
Basal Surface-Layer Properties in Flowing Snow
Authors: Lang T. E. , Dent J. D.
Published: September 2017

Experiments on the behavior of the active granular layer between flowing snow and sintered basal snow were performed by laboratory simulation of the layer. Layer thickness, its velocity profile, kinematic viscosity, and shear locking stress were estimated fron low-velocity tests. Variation in these parameters over a temperature range from -5 to -18°C, for overburden pressures of 1180 and 2360 N m−2, and for surface hardness in the range 0.4 to 4.0 N m−2 were evaluated. Results show strong dependence between surface hardness and layer viscosity, and near linear dependence between shear locking stress and overburden pressures.
Determination of Avalanche Dynamics Friction Coefficients from Measured Speeds
Authors: McClung D. M. , Schaerer P. A.
Published: September 2017

An avalanche dynamics model, appropriate for complex terrain, for real avalanche paths was developed by Perla, Cheng and McClung in 1980. The model has two friction terms, one for sliding friction which is independent of speed, and one for turbulent friction which is proportional to V2, where V is the centre-of-mass speed along the incline. By introducing speed maxima for avalanches, along with start and stop reference positions, it is possible to determine the the two constant friction coefficients for the model. When this is done, it is found that speed data often exceed a model speed limit implied by the application of V = 0 at the start and stop positions. This effect is illustrated by analytic solutions of the relevant equations, as well as numerical solutions for actual avalanche paths. Some limitations and properties of the fundamental modelling are outlined and suggestions given for future use of such models.
Icing Measurements on Fixed and Rotating Cylinders
Authors: McComber P. , Laforte J.-L. , Bouchard D. , Nguyen D. D.
Published: September 2017

There is at present a need to develop a better technique for measuring the rate of icing on structures such as, for example, overhead transmission lines. For aircraft and helicopter icing, the most widely used method of measurement is the rotating cylinder. However, for measuring the icing of structures, this method is difficult to apply and also less accurate due to lower wind velocities. Different approaches are now being developed using fixed cylinders.

Icing tests were conducted with fixed and rotating cylinders in a wind tunnel. The rate of icing was obtained through measurements of volume, accretion cross-section and time of deposition. Tests were made using five different liquid water contents and droplet diameter spectra, and four cylinder diameters, keeping the wind velocity and temperature constant. The rate of icing is presented as a function of the diameters of the fixed and rotating cylinders for each of the liquid water contents tested. Results indicate that at lower wind velocities the accretion rate is overestimated for the smaller rotating cylinders. This difference is probably due to the variation of the collection efficiency with diameter. From these results it is suggested that the rate of ice accretion on structures should be based on at least two fixed cylinders of different small sizes in order to take into account the effect of the collection efficiency.
Indentation of an S2 Floating Ice Sheet in the Brittle Range
Authors: Michel B. , Blanchet D.
Published: September 2017

The problem of a floating ice sheet hitting a structure with a vertical face appears to be a simple one but, in fact, has only been solved for a limited number of cases. Research work on this question usually reports on an indentation coefficient which relates the average pressure on the indenter to the uniaxial crushing strength of the ice. Very few tests have been made in the brittle range of ice failure. In this particular area of study, this paper reports on 27 tests that were conducted in a cold-room water basin where controlled S2 floating ice sheets were produced with a surface area of 4 × 4 m, three sides being fully restrained and the other, freely float! no, being submitted to the impact of the moving indenter. All tests were carried out at computed indentation rates varying from 0.017 to 0.34 s-1. In this range this ice would normally be considered to act as a brittle material. The thickness of the ice sheets varied from 1.2 to 9.0 cm and the indenter width from 5 cm to 1 m. Overall, the aspect ratio relating these two parameters could be varied from 0.5 to 83.

Results have shown that for aspect ratios <5, there was an important oscillatory effect which caused the formation of pi asti fi ed triangles in front of the indenter, increasing its resistance as it would under ductile conditions. Because of this plastification, an extrusion effect appeared in front of the indenter as the broken ice crystals were blown up and down in front of the fast-moving indenter. The theory of plasticity which gives an indentation coefficient of 2.97 seems to apply in this case. Another mode of failure which occurred with aspect ratios 5 was cleavage in the plane of the ice sheet which also gives a higher indentation coefficient for S2 ice, but of the same order of magnitude as previously.

For intermediate values of the aspect ratio, between 5 and 20, the theory of elasticity used by Michel (1978) seems to apply well. Shear cracks are first formed on both sides of the square indenter and control the maximum pressure when they propagate inside forming big triangles in front of it.

Finally, for aspect ratios ~>20, buckling of the ice occurs, either after or at the same time as the formation of wedges, together with a reduction in the indentation coefficient to a value close to that given by the theory of buckling of a truncated 45° wedge with a hinged edge.
Modelling the Flow of Mass and Energy within a Snowpack for Hydrological Forecasting
Authors: Morris E. M.
Published: September 2017

This paper describes a deterministic, distributed snow-melt model which has been developed for the Systeme Hydrologique Européen (SHE), The model is based on partial differential equations describing the flow of mass and energy through the snow. These equations are solved by an implicit, iterative finite-difference method. The behaviour of the model is investigated using data from a sub-Arctic site in Scotland.
Modelling Techniques in Applied Glaciology: Numerical Modelling of Avalanches
Authors: Brugnot G.
Published: September 2017

We consider the paper by Brugnot and Pochat (1981), which describes a one-dimensional model applied to a snow avalanche. The main advance made here is the introduction of the second dimension in the runout zone. Indeed, in the channelled course, we still use the one-dimensional model, but, when the avalanche spreads before stopping, we apply a (x, y) grid on the ground and six equations have to be solved: (1) for the avalanche body, one equation for continuity and two equations for momentum conservation, and (2) at the front, one equation for continuity and two equations for momentum conservation. We suppose the front to be a mobile jump, with longitudinal velocity varying more rapidly than transverse velocity.

We solve these equations by a finite difference method. This involves many topological problems, due to the actual position of the front, which is defined by its intersection with the reference grid (SI, YJ). In the near future our two directions of research will be testing the code on actual avalanches and improving it by trying to make it cheaper without impairing its accuracy.
EVALUATING STRESS AMELIORATION OF ORAL VITAMIN C IN BUCKS EXPOSED TO LONG TERM ROAD TRANSPORTATION AND STOCKING
Authors: Biobaku K. T. , Agaie B. M. , Aremu A.
Published: September 2017

Forty-eight apparently healthy Sahel bucks were used in this study; sixteen were at high stocking, sixteen bucks at low stocking and sixteen not transported considered as control.  Stress of transportation was induced by transporting animals from Sokoto, North-Western Nigeria to Abeokuta, South-Western Nigeria. Haematological and some biochemical parameters including stress biomarkers such as glutathione-S-transferase, superoxide dismutase (SOD), malondialdehyde (MDA) and thyroid hormones; triiodothyronine (T3) and tetraiodothyronine (T4) were assessed. There was a significant (P<0.05) increase in AST, ESR at low stocking and significantly (P<0.05) increased in percentages of neutrophils at high stocking rate. Lymphocytes and eosinophils significantly (P<0.05) increased at low stocking rates. N:L and monocytes significantly (P<0.05) decreased at low stocking. Conclusively, ascorbic acid improved recovery from general adaptive syndrome of long transportation at low stocking when welfare regulation is enforced, when compare to high stocking.
HAEMATOLOGICAL PROFILE OF THE ONE-HUMPED CAMEL SUBJECTED TO PACKING (LOAD-CARRYING) IN THE HARMATTAN SEASON IN THE SEMI-ARID REGION OF NIGERIA
Authors: Adah A. S. , Ayo J. O. , Rikwot P. I. , Aluwong T. , Arimie D. I.
Published: September 2017

The study was conducted to determine the effects of packing on some haematological responses in the one-humped camel (Camelus dromedarius) during the harmattan season in the semi-arid zone of Nigeria. The study was conducted using 8 experimental camels which were packed with bags of grains of 200 kg, while 4 camels served as the control group only trekked but were not packed. Ambient temperature (AT) and relative humidity (RH) of the experimental site were recorded three days prior to the experiment and on the experimental day at 06.00 h, 12.00 h and 15.00 h. Some haematological parameters were determined in all the camels. The mean AT and RH values ranged between 22-36.50 ºC and 26-36 %, respectively. The erythrocyte count, TP and PCV values were significantly higher (P < 0.05) in experimental camels than control camels after the experiment. The changes recorded in some of the parameters demonstrated that compensatory mechanisms were adopted by the camels to reduce the adverse effects of stress of packing. It is therefore recommended that a potent antioxidant should be administered to camels before subjecting them to packing to ameliorate the effects of stress of packing.
ISOLATION AND MOLECULAR DETECTION OF TURKEYPOX VIRUS FROM TURKEY FOR THE FIRST TIME IN BANGLADESH
Authors: Haydar M. R. , Ara M. S. , Soma S. S. , Rahman M. M. , Rahman M. B. , Rahman M. T.
Published: September 2017

Turkey rearing is getting popularity day by day in Bangladesh. Turkeypox is an important viral disease of turkey with great economic importance. In this study, turkeypox virus was isolated from a clinical case in Mymensingh, Bangladesh. Virus isolation was carried out through serial passage of viral inoculum into developing chicken embryo through chorioallantoic membrane (CAM) route. The virus isolate was confirmed by PCR targeting pox virus P4b gene. This is the first report of the isolation and PCR based molecular detection of turkeypox virus from a clinical case in Bangladesh.
Prevalence and antibiotic susceptibility pattern of Escherichia coli in cattle on Bathan and intensive rearing system
Authors: Gupta Mukta Das , Islam Mazharul , Sen Arup , Sarker Md Samun , Das Ashutosh
Published: September 2017

The aim of this longitudinal study was to verify the prevalence and antibiotic susceptibility pattern of Escherichia coli (E. coli) in cattle reared on Bathan and intensive farming system in Bangladesh. Fecal materials originated from recto anal junction (RAJ) of 100 cattle used for primary screening on MacConkey agar. The diversities among the pink color colony producing isolates on MacConkey agar were verified by conventional cultural methods and biochemical tests. Phenotypically positive E. coli isolates were further investigated for the variations in the antimicrobial resistance profiles to 10 selected antibiotics, by the disk-diffusion method. This study revealed that the overall prevalence of E. coli was 70% of in the rectal swab sample of cattle. However, the prevalence of E. coli was found significantly higher (p= 0.002) in cattle under intensive farming (84%) than cattle on Bathan (56%). Antibiotic susceptibility pattern shows that among the tested isolates 83%, 73%, 68% and 64% were sensitive to chloramphenicol, gentamicin, ciprofloxacin and ampicillin, respectively. On the other hand, all the 70 (100%) E. coli isolates were found resistant to tetracycline and sulfamethoxazole. A high antibiotic resistance profile was also found against amoxicillin (90%), ampicillin (87%), nalidixic acid (86%) and erythromycin (83%). In total, 24 (34%) isolates were resistant against ?2 antimicrobials. The result clearly shows that antibiotic resistant E. coli isolates are commonly present in cattle of different management systems (intensive and Bathan). Therefore, careful selection of appropriate antibiotics with optimal doses might be ensured to prevent the emergence of antibiotic resistance bacteria.Microbes and Health, June 2017, 6(1): 1-4
Fluorescence and Reflectance Sensor Comparison in Winter Wheat
Authors: Zecha Christoph , Link Johanna , Claupein Wilhelm
Published: September 2017

Nitrogen (N) is the most important macronutrient in plant production. For N application, legislation requirements have raised, and the purchasing costs have increased. Modern sensors can help farmers to save costs, to apply the right quantity, and to reduce their impact on the environment. Two spectrometers and one fluorescence sensor have been used on a vehicle sensor platform for N detection in wheat (Triticum aestivum L.) field trials over three years. The research fields were divided into plots, and the N input ranged from 60 to 180 kg N ha−1 in six levels. The OSAVI (optimized soil-adjusted vegetation index) showed a similar value pattern to the NDVI (normalized difference vegetation index) and the CropSpec index for the investigated factors. The red-edge inflection point (REIP) index showed high correlations to N (indicated by r2 between 0.6 and 0.8), especially in June and July. The developed models from the fluorescence indices FERARI, NBIR, FLAV, and the spectrometer indices CropSpec and HVI show high correlations (r2 = 0.5–0.8) to yield and may be used for future yield predictions. The Multiplex Research™ fluorescence sensor (Force-A, Orsay, France) was the most convenient sensor with a simple measurement method and a non-proprietary file output. The implementation into existing agricultural vehicle networks is still necessary, being able to use it on a farm for online N recommendations.
Profiling of Polyphenol Composition and Antiradical Capacity of Erica cinerea
Authors: Aires Alfredo , Carvalho Rosa
Published: September 2017

The aim of the current study was to determine the profile and content of polyphenols present in Erica cinerea, an important plant species from Northern Portuguese flora and often reported as having anti-inflammatory, antioxidant, and anti-radical activity. The analysis of polyphenols was performed by HPLC-DAD/UV-Vis, and the 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) method was used to evaluate its radical scavenging activity. HPLC analysis showed that both plants presented a great diversity of compounds, with 33% flavones, 28% flavanols, and 26% hydroxycinnamic acids. The antiradical activity was dose-dependent, and the IC50 values were 0.251 mg mL−1. Based on our study, E. cinerea presented interesting bioactive compounds and it can be used to extract and purify bioactive polyphenols to be used in pharmaceutical or agro-food industries.
Application of Artificial Neural Networks to Ship Detection from X-Band Kompsat-5 Imagery
Authors: Hwang Jeong-In , Chae Sung-Ho , Kim Daeseong , Jung Hyung-Sup
Published: September 2017

For ship detection, X-band synthetic aperture radar (SAR) imagery provides very useful data, in that ship targets look much brighter than surrounding sea clutter due to the corner-reflection effect. However, there are many phenomena which bring out false detection in the SAR image, such as noise of background, ghost phenomena, side-lobe effects and so on. Therefore, when ship-detection algorithms are carried out, we should consider these effects and mitigate them to acquire a better result. In this paper, we propose an efficient method to detect ship targets from X-band Kompsat-5 SAR imagery using the artificial neural network (ANN). The method produces the ship-probability map using ANN, and then detects ships from the ship-probability map by using a threshold value. For the purpose of getting an improved ship detection, we strived to produce optimal input layers used for ANN. In order to reduce phenomena related to the false detections, the non-local (NL)-means filter and median filter were utilized. The NL-means filter effectively reduced noise on SAR imagery without smoothing edges of the objects, and the median filter was used to remove ship targets in SAR imagery. Through the filtering approaches, we generated two input layers from a Kompsat-5 SAR image, and created a ship-probability map via ANN from the two input layers. When the threshold value of 0.67 was imposed on the ship-probability map, the result of ship detection from the ship-probability map was a 93.9% recall, 98.7% precision and 6.1% false alarm rate. Therefore, the proposed method was successfully applied to the ship detection from the Kompsat-5 SAR image.
Assessment of Natural Ventilation Potential for Residential Buildings across Different Climate Zones in Australia
Authors: Tan Zijing , Deng Xiang
Published: September 2017

In this study, the natural ventilation potential of residential buildings was numerically investigated based on a typical single-story house in the three most populous climate zones in Australia. Simulations using the commercial simulation software TRNSYS (Transient System Simulation Tool) were performed for all seasons in three representative cities, i.e., Darwin for the hot humid summer and warm winter zone, Sydney for the mild temperate zone, and Melbourne for the cool temperate zone. A natural ventilation control strategy was generated by the rule-based decision-tree method based on the local climates. Natural ventilation hour (NVH) and satisfied natural ventilation hour (SNVH) were employed to evaluate the potential of natural ventilation in each city considering local climate and local indoor thermal comfort requirements, respectively. The numerical results revealed that natural ventilation potential was related to the local climate. The greatest natural ventilation potential for the case study building was observed in Darwin with an annual 4141 SNVH out of 4728 NVH, while the least natural ventilation potential was found in the Melbourne case. Moreover, summer and transition seasons (spring and autumn) were found to be the optimal periods to sustain indoor thermal comfort by utilising natural ventilation in Sydney and Melbourne. By contrast, natural ventilation was found applicable over the whole year in Darwin. In addition, the indoor operative temperature results demonstrated that indoor thermal comfort can be maintained only by utilising natural ventilation for all cases during the whole year, except for the non-natural ventilation periods in summer in Darwin and winter in Melbourne. These findings could improve the understanding of natural ventilation potential in different climates, and are beneficial for the climate-conscious design of residential buildings in Australia.
Stark Broadening from Impact Theory to Simulations
Authors: Stamm Roland , Hannachi Ibtissem , Meireni Mutia , Godbert-Mouret Laurence , Koubiti Mohammed , Marandet Yannick , Rosato Joël , Dimitrijević Milan , Simić Zoran
Published: September 2017

Impact approximation is widely used for calculating Stark broadening in a plasma. We review its main features and different types of models that make use of it. We discuss recent developments, in particular a quantum approach used for both the emitter and the perturbers. Numerical simulations are a useful tool for gaining insight into the mechanisms at play in impact-broadening conditions. Our simple model allows the integration of the Schrödinger equation for an emitter submitted to a fluctuating electric field. We show how we can approach the impact results, and how we can investigate conditions beyond the impact approximation. The simple concepts developed in impact and simulation approaches enable the analysis of complex problems such as the effect of plasma rogue waves on hydrogen spectra.
From Normal Surfaces to Normal Curves to Geodesics on Surfaces
Authors: Appleboim Eli
Published: September 2017

This paper gives a study of a two dimensional version of the theory of normal surfaces; namely, a study o normal curves and their relations with respect to geodesic curves. This study results with a nice discrete approximation of geodesics embedded in a triangulated orientable Riemannian surface. Experimental results of the two dimensional case are given as well.
Self-Assembly of Human Serum Albumin: A Simplex Phenomenon
Authors: Thakur Garima , Prashanthi Kovur , Jiang Keren , Thundat Thomas
Published: September 2017

Spontaneous self-assemblies of biomolecules can generate geometrical patterns. Our findings provide an insight into the mechanism of self-assembled ring pattern generation by human serum albumin (HSA). The self-assembly is a process guided by kinetic and thermodynamic parameters. The generated protein ring patterns display a behavior which is geometrically related to a n-simplex model and is explained through thermodynamics and chemical kinetics.
Substituting Sodium Hydrosulfite with Sodium Metabisulfite Improves Long-Term Stability of a Distributable Paper-Based Test Kit for Point-of-Care Screening for Sickle Cell Anemia
Authors: Torabian Kian , Lezzar Dalia , Piety Nathaniel , George Alex , Shevkoplyas Sergey
Published: September 2017

Sickle cell anemia (SCA) is a genetic blood disorder that is particularly lethal in early childhood. Universal newborn screening programs and subsequent early treatment are known to drastically reduce under-five SCA mortality. However, in resource-limited settings, cost and infrastructure constraints limit the effectiveness of laboratory-based SCA screening programs. To address this limitation our laboratory previously developed a low-cost, equipment-free, point-of-care, paper-based SCA test. Here, we improved the stability and performance of the test by replacing sodium hydrosulfite (HS), a key reducing agent in the hemoglobin solubility buffer which is not stable in aqueous solutions, with sodium metabisulfite (MS). The MS formulation of the test was compared to the HS formulation in a laboratory setting by inexperienced users (n = 3), to determine visual limit of detection (LOD), readout time, diagnostic accuracy, intra- and inter-observer agreement, and shelf life. The MS test was found to have a 10% sickle hemoglobin LOD, 21-min readout time, 97.3% sensitivity and 99.5% specificity for SCA, almost perfect intra- and inter-observer agreement, at least 24 weeks of shelf stability at room temperature, and could be packaged into a self-contained, distributable test kits comprised of off-the-shelf disposable components and food-grade reagents with a total cost of only $0.21 (USD).
Use of Wavelet Transform to Detect Compensated and Decompensated Stages in the Congestive Heart Failure Patient
Authors: Sharma Pratibha , Newman Kimberly , Long Carlin , Gasiewski A. , Barnes Frank
Published: September 2017

This research work is aimed at improving health care, reducing cost, and the occurrence of emergency hospitalization in patients with Congestive Heart Failure (CHF) by analyzing heart and lung sounds to distinguish between the compensated and decompensated states. Compensated state defines stable state of the patient but with lack of retention of fluids in lungs, whereas decompensated state leads to unstable state of the patient with lots of fluid retention in the lungs, where the patient needs medication. Acoustic signals from the heart and the lung were analyzed using wavelet transforms to measure changes in the CHF patient’s status from the decompensated to compensated and vice versa. Measurements were taken on CHF patients diagnosed to be in compensated and decompensated states by using a digital stethoscope and electrocardiogram (ECG) in order to monitor their progress in the management of their disease. Analysis of acoustic signals of the heart due to the opening and closing of heart valves as well as the acoustic signals of the lungs due to respiration and the ECG signals are presented. Fourier, short-time Fourier, and wavelet transforms are evaluated to determine the best method to detect shifts in the status of a CHF patient. The power spectra obtained through the Fourier transform produced results that differentiate the signals from healthy people and CHF patients, while the short-time Fourier transform (STFT) technique did not provide the desired results. The most promising results were obtained by using wavelet analysis. Wavelet transforms provide better resolution, in time, for higher frequencies, and a better resolution, in frequency, for lower frequencies.
Liver Cancer: Molecular Characterization, Clonal Evolution and Cancer Stem Cells
Authors: Castelli Germana , Pelosi Elvira , Testa Ugo
Published: September 2017

Liver cancer is the second most common cause of cancer-related death. The major forms of primary liver cancer are hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). Both these tumors develop against a background of cirrhotic liver, non-alcoholic fatty liver disease, chronic liver damage and fibrosis. HCC is a heterogeneous disease which usually develops within liver cirrhosis related to various etiologies: hepatitis B virus (HBV) infection (frequent in Asia and Africa), hepatitis C virus (HCV), chronic alcohol abuse, or metabolic syndrome (frequent in Western countries). In cirrhosis, hepatocarcinogenesis is a multi-step process where pre-cancerous dysplastic macronodules transform progressively into HCC. The patterns of genomic alterations observed in these tumors were recently identified and were instrumental for the identification of potential targeted therapies that could improve patient care. Liver cancer stem cells are a small subset of undifferentiated liver tumor cells, responsible for cancer initiation, metastasis, relapse and chemoresistance, enriched and isolated according to immunophenotypic and functional properties: cell surface proteins (CD133, CD90, CD44, EpCAM, OV-6, CD13, CD24, DLK1, α2δ1, ICAM-1 and CD47); the functional markers corresponding to side population, high aldehyde dehydrogenase (ALDH) activity and autofluorescence. The identification and definition of liver cancer stem cells requires both immunophenotypic and functional properties.