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In endoscopic cricopharyngeal myotomy, surgeons sometimes have concerns about performing an adequate incision with only a narrow intra-cavital view from one direction. In order to overcome these issues, fluoroscopic radiography was used during endoscopic cricopharyngeal myotomy.
Peri-operative fluoroscopic radiography was utilised to check the position of the diverticuloscope, and to confirm the extent of the incision during surgery. A balloon catheter was used to determine whether the cricopharyngeal muscle was sufficiently resected. Blood loss, peri-operative complications, and functional oral swallowing scale and penetration aspiration scale scores were evaluated.
In 12 out of 15 patients, intra-operative fluoroscopic radiography showed the diverticuloscope positioned in the post-cricoid area, and the cricopharyngeal muscle was raised and the surgery completed without adverse effect. Swallowing functions improved following surgery.
Intra-operative fluoroscopy might improve endoscopic cricopharyngeal myotomy by allowing surgeons to confirm the extent of resection, and by reducing peri-operative morbidity and complication rates.
Yield and landscape are commonly used to guide management zone delineation. However, production system choice and management can interact with landscape attributes and weather. The objective of this study was to evaluate forage yield and soil properties in three landscape defined (elevation based) management zones, and under two different grazing systems. Changes in soil properties (soil strength, bulk density, moisture, bioavailable nutrients) and forage productivity (biomass), as related to grazing management and management zone, were measured. Bulk density, moisture, and forage biomass were greater at higher elevation. Soil strength decreased as elevation increased, and was greater near-surface after winter grazing ended. The response of landscape delineated management zones varied with extreme weather conditions and treatment. Lower zones were more sensitive to weather extremes than higher elevations, directly affecting biomass accumulation. In conclusion, we observed interactions between the grazing treatments and the management zones.
This paper investigates the focal location effects on the penetration depth of molten region surrounding a paraboloid of revolution-shaped cavity (i.e. keyhole of this model) irradiated by a moving focused energy beam, which profile of intensity is assumed to be Gaussian distribution. Considering the momentum balance at the base of the keyhole, a quasi-steady-state thermal model relative to a constant-speed moving high-energy beam and paraboloid of revolution-shaped cavity is developed in a parabolic coordinate system. The analytical solution is obtained for this model with the adiabatic condition directly set on the workpiece surface for semi-infinite domain instead of the image method for infinite domain using the separation-of-variables method. The analytical solution of this model gives a reasonable prediction for the cavity temperatures. The predicted relation of the penetration depth to the focal location agrees with the available measured data. The effects of focal convergence angle and spot size on the penetration depth are also discussed.
The study of glaciers and ice caps in remote and cloudy regions remains difficult using current remote sensing tools. Here the potential of stereo radargrammetry (SRG) with RADARSAT-2 Wide Ultra-Fine images is explored for DEM extraction, elevation changes and mass-balance calculations on Barnes Ice Cap (Nunavut, Canada). Over low-relief terrain surrounding Barnes, a vertical precision of ~7 m (1σ confidence level) is measured, as well as an average vertical bias of ~4 m. Moreover, we show that the C-band penetration depth over the ice cap is insignificant at this time of the year (i.e. late ablation season). This is likely due to a wet surface and the presence of superimposed ice that leads to a surface radar response. Comparing the SRG DEMs with other datasets, an historical glacier-wide mass balance of −0.52 ± 0.19 m w.e. a−1 is estimated for 1960–2013, whereas it decreases to −1.06 ± 0.84 m w.e. a−1 between 2005 and 2013. This clear acceleration of mass loss is in agreement with other recent studies. Given its all-weather functionality and its possible use without ground control points, the RADARSAT-2 SRG technology represents an appropriate alternative for glacier monitoring in cloudy and remote regions.
Background: A large proportion of people living with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) suffer from neurocognitive impairment (NCI). The causes of the NCI are multifold in HIV infection although a subset of HIV/AIDS patients are affected by the spectrum syndrome, HIV-associated neurocognitive disorder (HAND). We investigated the Montreal Cognitive Assessment (MoCA) in relation to clinical, demographic and laboratory findings as well as its ability to predict symptomatic HAND (sHAND) among patients with HIV/AIDS. Methods: All subjects were receiving regular HIV care including CD4+ T cell counts, plasma viral load measurements, clinical evaluations and antiretroviral therapy. The diagnosis of sHAND was based upon clinical, neuroimaging, and neuropsychological assessments.Results: Among HIV-1 seropositive subjects (n=125), ethnicity, education and employment were positively correlated with their MoCA scores (p<0.05). In contrast, polypharmacy, central nervous system penetration-effectiveness (CPE) score, antiretroviral drug exposure, substance use and nucleoside/nucleotide reverse transcriptase inhibitor side effects were negatively correlated with MoCA scores (p<0.05). Of note, MoCA scores were not associated with CD4 T cell nadir levels, age, peak viral load, or veterans aging cohort study index. In subjects with or without sHAND, mean MoCA scores differed (sHAND, 22.8±3.51; non-HAND 25.2±2.64) (p<0.05) with a receiver operating characteristic curve showing an area under curve of 0.71 and an optimal MoCA cut-off value of 23.5 when compared to the established diagnostic paradigm. Conclusions: MoCA scores were generally lower in this HIV/AIDS population compared to reported scores in the general population. MoCA performance was associated with multiple clinical variables but displayed limited predictive utility in detecting sHAND.
Continuous ingestion of the phloem sap of plants by aphids can remove a significant amount of photoassimilates. Based on our earlier works, we hypothesized that due to the reduced aphid feeding time caused by antibiosis, wheat plants may achieve growth tolerance to aphids. We tested this hypothesis using three wheat cultivars, XY22 (Xiaoyan22), AK58 (Bainongaikang58) and XN979 (Xinong979) and the grain aphid, Sitobion avenae. In the choice test, S. avenae did not show any preference among the three wheat cultivars. However, S. avenae had a lower body weight and a lower intrinsic rate of increase when feeding on XY22 than on AK58 and XN979. The electrical penetration graph results indicated that S. avenae had significantly shorter mean and total phloem ingestion periods on XY22 than on AK58 or XN979. The aphids required a similar time to reach the phloem sap on the three wheat cultivars, but required more time to establish sustained phloem ingestion on XY22. These results suggest that the resistance factors of XY22 may be phloem based. Moreover, XY22 suffered less biomass loss in response to aphid infestation compared with XN979, suggesting that XY22 also had a better growth tolerance to S. avenae than XN979. Wheat resistance level to S. avenae was partially correlated with plant photosynthetic rates, and peroxidase activities. These results confirmed that the limitation in aphid feeding from plant phloem in wheat cultivar XY22 was related to antibiosis but not antixenosis, which caused XY22 tolerance to S. avenae.
The standard penetration test (SPT) is the most common test conducted in the field, and it is used to determine in situ properties of different soils. Although it is a matter of debate, these tests are also used for the determination of the consistency of fine-grained soils, whereby the test results can also be utilized to establish numerous empirical correlations to predict the strength of soils in the field. In this study, unsupervised clustering algorithms were employed to classify the SPT standard penetration resistance value (SPT-N) in the field. In this scope, shear strength and liquidity index parameters were used to classify the SPT-N values by taking the classification system of Terzaghi and Peck (1967) into consideration. The results showed that the input parameters were successful for classifying the SPT-N value to an acceptable degree of strength attribute. Therefore, in cases where the SPT tests are unreliable or could not be performed, laboratory tests on undisturbed specimens can give valuable information regarding the consistency and SPT-N value of the soil specimen under investigation. Data in this study is based on several tests that were conducted in a region; nevertheless, it is advised that the results of this study should be evaluated using global data.
In the conservation of fragile fossil bone material, impregnation by solvent-borne consolidant is often required. Understanding the mode of penetration of consolidants into fossil bone is of crucial importance. It is governed by a variety of factors; neutron imaging is a powerful tool to monitor and visualise this penetration (non-destructively). The consolidation of a vertebrate fossil from the Maastrichtian of the southeast Netherlands was imaged at the High Flux Reactor facility at Petten, the Netherlands. The analysis shows current conservation practice to result in a sufficiently deep and isotropic penetration.
Probing behaviour (prior to parturition) and parturition of two clones (PS01 and N116) of the pea aphid, Acyrthosiphon pisum on two genotypes (near-isogenic lines (NILs)) (Q174_5.13 and Q174_9.10) of Medicago truncatula were investigated using electrical penetration graph (EPG) coupled with simultaneous visual monitoring for parturition. Line Q174_5.13 has been reported to show a phloem-based resistance to feeding in the clone PS01 but to be susceptible to the clone N116, whereas Q174_9.10 has shown to be susceptible to both aphid clones. The time taken to first parturition by clone PS01 was similar on Q174_5.13 and Q174_9.10. Prior to parturition, no aphids on Q174_5.13 contacted phloem, but 5% of the aphids on Q174_9.10 showed phloem salivation (recognized by EPG pattern E1). No phloem contact was observed with aphid clone N116 on either NILs of Medicago before first parturition occurred, and the time taken to first larviposition was similar on Q174_5.13 and Q174_9.10. The results indicate that the initiation of parturition of the clone PS01 and N116 on both NILs does not require the phloem contact and seems unchanged by a phloem-based resistance mechanism to feeding on Medicago. This finding suggests that host recognition and decisions about parturition occur before phloem contact or ingestion, and act independently on R-gene-mediated resistance.
The black currant-lettuce aphid, Nasonovia ribisnigri, is an important pest of cultivated lettuce, Lactuca sativa. Since 1982, the control of this aphid on lettuce is largely based on host plant resistance, conferred by the Nr gene, introgressed from Lactuca virosa. The resistance mechanism remains to be identified. N. ribisnigri populations virulent on the Nr-based resistance in lettuce have emerged in several locations in Europe since 2007. The objective of this study was to investigate the resistance mechanism mediated by the Nr gene in lettuce by detailed studies of aphid feeding behaviour and performance. Both avirulent (Nr:0) and virulent (Nr:1) biotypes of N. ribisnigri were studied on five resistant and two susceptible near isogenic lines (NILs). In addition, survival and colony development were quantified. Nr:0 aphids showed a strong decrease in sieve element ingestion and took longer to accept a sieve element on resistant NILs compared with susceptible NILs, and no aphids survived on the resistant NIL. Nr:1 aphids fed and performed equally well on the resistant and susceptible NILs. The resistance mechanism against Nr:0 aphids encoded by the Nr gene seems to be located in the phloem, although we also observed differences in feeding behaviour during the pathway phase to the phloem. Nr:1 aphids were highly virulent to the resistance conferred by the Nr gene. The consequences of the appearance of Nr:1 aphids for control of N. ribisnigri are discussed.
Fluorescence resonance energy transfer (FRET) microscopy is a powerful technique to quantify dynamic protein-protein interactions in live cells. Total internal reflection fluorescence (TIRF) microscopy can selectively excite molecules within about 150 nm of the glass-cell interface. Recently, these two approaches were combined to enable high-resolution FRET imaging on the adherent surface of living cells. Here, we show that interference fringing of the coherent laser excitation used in TIRF creates lateral heterogeneities that impair quantitative TIRF-FRET measurements. We overcome this limitation by using a two-dimensional scan head to rotate laser beams for donor and acceptor excitation around the back focal plane of a high numerical aperture objective. By setting different radii for the circles traced out by each laser in the back focal plane, the penetration depth was corrected for different wavelengths. These modifications quell spatial variations in illumination and permit calibration for quantitative TIRF-FRET microscopy. The capability of TIRF-FRET was demonstrated by imaging assembled cyan and yellow fluorescent protein–tagged HIV-Gag molecules in single virions on the surfaces of living cells. These interactions are shown to be distinct from crowding of HIV-Gag in lipid rafts.
Surface-soil structural condition in perennial pastures is expected to be modified by how forage is (a) harvested through haying or grazing and (b) stimulated through source of nutrients applied, as well as by compactive forces, e.g., grazing cattle or hay harvest machinery. Changes in surface-soil condition can affect hydrologic processes that have important implications for plant growth, greenhouse gas emissions and off-site water quality. We determined the effects of harvest management and nutrient source on the rate of ponded water infiltration and penetration resistance in a bermudagrass [Cynodon dactylon (L.) Pers.]/tall fescue (Lolium arundinaceum Schreb. S.J. Darbyshire) pasture on a Typic Kanhapludult in Georgia. During a period when soil was wet (61% water-filled pore space), the rate of water infiltration was 2.8 ± 1.5 times greater when forage was left unharvested as when hayed or grazed (mean ± standard deviation among nine nutrient source × harvest management comparisons). During a subsequent period, when soil was dry (28% water-filled pore space), the rate of water infiltration followed the same treatment pattern, but was not statistically different among harvest-management practices (1.5 ± 0.4 times greater between unharvested and other systems). Penetration resistance of the surface at 10 cm depth followed the order: unharvested (62 J) < hayed (100 J) < low grazing pressure (119 J) < high grazing pressure (137 J). Water infiltration during the wet period was negatively related (P ⩽ 0.01) to soil-water content (r = − 0.57), penetration resistance at 0–10 cm depth (r = − 0.50) and bulk density at 3–6 cm depth (r = − 0.53), but was positively related to surface residue C (r = 0.47) and soil organic C concentration at 12–20 cm depth (r = 0.42). These results suggest that complex soil physical (i.e., aggregation, penetration resistance and infiltration) and biological (i.e., plant growth, surface residues and soil organic matter) interactions occur in pastures. We conclude that well-managed grazing systems with excellent ground cover should have adequate hydrologic condition to promote pasture productivity and limit environmental contamination from runoff. Further work is needed to understand the linkages between field- and watershed-scale hydrology in perennial pastures and their implications on water quality.
Gemstones are pieces of materials that once cut and polished are used as jewels or adornments. Gemstones may be single crystal (such as diamonds), polycrystalline (such as lapis lazuli), or amorphous (such as amber). In any case, gems may have inclusions that may yield a variety of optic effects. It is also important to unravel the crystal structure of the inclusion(s) in order to determine the origin of the gem and to help to understand their formation mechanism. Here, we expand the use of powder diffraction to identify crystalline inclusions in bulk gemstones highlighting Mo Kα radiation to penetrate within compact gems. Initially, rock crystal quartz with rutile needles was investigated and rutile diffraction peaks were more conspicuous in the Mo pattern than in the Cu pattern. Next, rock crystal quartz with beetle legs was characterized and the red iron oxide inclusion was identified as hematite. The study of a fake gem, glass showing aventurine effect, gave the diffraction peaks of metallic copper. Later, polycrystalline gems, moss agate, and aventurine quartz were also studied. The powder patterns of these compact gemstones could be successfully fitted using the Rietveld method. Finally, we discuss opportunities for further improvements in laboratory powder diffraction to characterize inclusions in compact gems.
Tests of sperm DNA damage and sperm chromosome anomalies have also been developed. The advanced sperm tests yield information on the fertilizing capacity of human spermatozoa, as well as their ability to support normal embryonic development. The most common abnormalities involve the structure of the sperm tail, with defects in either the axoneme or outer dense fibers. Postcoital test (PCT) assesses the ability of sperm to traverse the cervical mucus, and is performed by examining the cervical mucus several hours after intercourse for the presence of sperm. The sperm penetration assay (SPA) utilizes hamster ova, which have had the zona pellucida enzymatically removed, allowing penetration by human spermatozoa. The hemizona assay uses zona pellucida from nonfertilizable, nonliving oocytes. Reactive oxygen species (ROS) are ubiquitous in aerobic biologic systems and are formed as a by-product of oxygen metabolism.
We have observed that when cercariae penetrate the skin of mice, there is influx into their tissues of Lucifer Yellow and certain labelled molecules of up to 20 kDa molecular weight. This observation was made using a variety of fluorescent membrane-impermeant compounds injected into the skin before the application of cercariae. This unexpected phenomenon was investigated further by transforming cercariae in vitro in the presence of the membrane-impermeant compounds and examining the distribution by microscopy. In schistosomula derived from this procedure, the nephridiopore and surface membrane were labelled while the pre- and post-acetabular glands were not labelled. The region associated with the oesophagus within the pharyngeal muscle clearly contained the fluorescent molecules, as did the region adjacent to the excretory tubules and the germinal mass. We used cercariae stained with carmine to aid identification of regions labelled with Lucifer Yellow. Although the mechanism of this influx is unclear, the observation is significant. From it, we can suggest an hypothesis that, during skin penetration, exposure of internal tissues of the parasite to external macromolecules represents a novel host-parasite interface.
The compressive stress distribution below the specimen surface of severely surface deformed steels by shot peening was investigated by using laboratory X-rays and high-energy X-rays from a synchrotron radiation source, SPring-8 in the Japan Synchrotron Radiation Research Institute. Medium carbon steel plates were heat treated in two different conditions. The Vickers hardness of materials A and B after heat treatment is 408 and 617 HV, respectively. The specimens were shot peened with fine cast iron particles of the size of 50 μm. The coverage was selected to be 5000%. For the synchrotron radiation, by using the monochromatic X-ray beam with several energy levels, the stress values at the arbitrary penetration depth were measured by the constant penetration depth method. The shot-peened specimens were fatigued under four-point bending. The improvement of fatigue strength of material A was not so large because of large surface roughness. On the other hand, for material B, the surface roughness was smaller and the fatigue strength was higher than that of ground specimens.
The suitability of image analysis by colour-based pixel classification to quantify lichen colonization on the surface of and within marble, travertine and mortar stonework has been investigated. High resolution images of lichenized stonework surfaces were acquired at different field sites using a scanner, thus avoiding invasive surveys, and the percentage cover of lichen species was subsequently measured in the laboratory using dedicated software. Furthermore, microphotographs of polished cross-sections of lichenized marble, travertine and mortar, stained using the periodic acid-Schiff (PAS) method to visualize hyphae, were produced by the same software to quantify hyphal spread within the substratum, a parameter which can be used more successfully than the commonly used depth of hyphal penetration to quantify how much the lichen has affected the conservation of a stone substratum. Significant statistical differences in hue, saturation and intensity (HSI) of the lichen thalli and PAS-stained hyphae, with respect to the lithic substrata, allowed the software to discriminate and quantify the lichen species cover on, and hyphal spread within, the three investigated lithotypes. Since such a quantitative approach highlights the volume of influence of lichens on stonework, where bioweathering processes are likely to develop, it could be used to support decisions on the preservation of our stone cultural heritage.
To optimize IVF conditions for BALB/c mice, which are known to have poor in vitro fertilizability, the requirements for sperm–ova interaction were studied by use of modified simplex optimization medium (mKSOM) as a basic medium. Modified human tubal fluid (mHTF) was used for sperm preincubation and acted as a positive control. When the two media were compared, neither capacitation nor fertilization was supported in mKSOM. Increasing the calcium concentration in mKSOM to 5 mM or more during sperm: ova coincubation improved zona penetration but not male pronuclear (MPN) formation to the same level as those cells incubated in mHTF. When medium osmolarity was varied from 230–305 mOsmol by NaCl at 5 mM CaCl2, MPN formation improved at 280 mOsmol or higher osmolarity to the same level as that found when using mHTF. When NaCl equivalent to 25–75 mOsmol was substituted with trehalose, no significant reduction in fertilization was observed. Substitution of NaCl equivalent to 75 mOsmol with other osmotic reagents (sucrose, choline chloride and sorbitol) resulted in similar levels of fertilization as found with mHTF, except for sorbitol, which reduced fertilization significantly caused by its detrimental effect on sperm viability. At isotonic osmolarity (305 mOsmol), maximum fertilization was observed at 5 mM CaCl2; lower or higher concentrations of CaCl2 resulted in reduced fertilization. Calcium and osmolarity, therefore, are important for sperm : ova interaction in BALB/c mice and the increases in calcium to 5 mM and osmolarity to 305 mOsmol are optimal for BALB/c sperm to penetrate through the zona and to form MPN.
The aim of this work was to characterize oocyte fertilization and embryo cleavage in nine AI bulls to find parameters suitable for prediction of in vitro fertility. According to the d8 blastocysts rate, they were categorized as high, medium and low productive (HP, MP and LP, mean: 25.4, 21.0 and 13.6% respectively) bulls. For these categories, oocyte penetration and fertilization efficiency were assessed at 6 and 18 hours post insemination (hpi), respectively. Some presumptive zygotes were cultured and cleaved and fast-cleaved embryo rates were checked at 44 hpi. The penetration rate was significantly higher for HP bulls than for MP and LP bulls (67.9 versus 50.3 and 33.1%; p < 0.01). The syngamy rate was significantly higher for HP bulls than for MP and LP bulls (21.4 versus 10.2 and 5.7%; p < 0.05). Conversely, no significant differences in fertilization rates were found among HP, MP and LP bulls. The cleavage rate was significantly higher for HP than LP bulls (82.4 versus 74.4%; p < 0.01). The fast cleavage rate was significantly higher for both HP and MP bulls, as compared with LP bulls (82.1 and 84.7 versus 73.5%; p < 0.01). A strong correlation was found between blastocyst production and penetration (r = 0.803), syngamy (r = 0.826), cleavage (r = 0.635) and fast cleavage (r = 0.709). In conclusion, all the evaluated parameters showed a predictive value, the most significant being early penetration and syngamy.
Existing penalty-based haptic rendering approaches are based on the penetration depth estimation in strictly translational sense and cannot properly take object rotation into account. We propose a new six-degree-of-freedom (6-DOF) haptic rendering algorithm which is based on determining the closest-point projection of the inadmissible configuration onto the set of admissible configurations. Energy is used to define a metric on the configuration space. Once the projection is found the 6-DOF wrench can be computed from the generalized penetration depth. The space is locally represented with exponential coordinates to make the algorithm more efficient. Examples compare the proposed algorithm with the existing approaches and show its advantages.