Beach Balls Research Articles

Revisiting the issue of "beach balls" in holmium laser enucleation of prostate: clinical and histological characterization.

To clinically and histologically characterize prostatic nodules resistant to morcellation ("beach balls," BBs). We reviewed a consecutive cohort of 559 holmium laser enucleation of the prostate (HoLEP) procedures performed between January 2020 and November 2023. The BBs group comprised 55 men (10%) and the control group comprised 504 men (90%). The clinical, intraoperative, outcome, and histologic data were statistically processed for the prediction of the presence of BBs and their influence on the perioperative course and outcome. The BBs group in comparison to the controls was older (75 vs 73years, respectively, p = 0.009) and had higher rates of chronic retention (51 vs 29%, p = 0.001), larger prostates on preoperative abdominal ultrasound (AUS) (140 vs 80cc, p = 0.006E-16), longer operating time (120 vs 80min, p = 0.001), higher weights of removed tissue (101 vs 60gr, p = 0.008E-10), higher complication rates (5 vs 1%, p = 0.03), and longer hospitalization (p = 0.014). A multivariate analysis revealed that larger prostates on preoperative AUS and older age independently predicted the presence of BBs which would prolong operating time. ROC analyses revealed that a threshold of 103cc on AUS predicted BBs with 94% sensitivity and 84% specificity. BBs were mostly characterized histologically by stromal component (p = 0.005). BBs are expected in older patients and cases of chronic retention. Prostatic volume is the most reliable predictor of their presence. They contribute to prolonged operating time and increased risk of complications. The predominantly stromal composition of the BBs apparently confers their resistance to morcellation.

On exact wave propagation analysis in a beach volleyball ball

Wave propagation and vibration state in the sports balls have important effects on the stability in movement and accuracy of hits. In some sports, similar to football and volleyball, the balls are subjected to continuous strong hits from players. In the current study, the wave propagation in a beach volleyball ball under the effect of temperature change, different material characteristics, different thicknesses, and the total mass is investigated. In this regard, the ball is modeled using a spherical shell structure and a higher-order displacement field is considered. The classical theory of elasticity is employed along with Hamilton’s principle for the spherical shell. The outcome equations with different boundary conditions are solved by engaging the discrete singular convolution method (DSCM). In addition, the finite element method is used to obtain the modal shape and natural frequency. The formulations and solution method are utilized in different steps of convergence examination, validation, and parametric study to acquire a comprehensive insight into the behavior of beach volleyball balls under the effect of the dynamic loading conditions. In specific, we are more interested in the phase velocity of the ball. The results are presented for different temperature changes and geometrical and material properties.

Cover Feature: Cyclic Disulfide Liposomes for Membrane Functionalization and Cellular Delivery (Chem. Eur. J. 45/2022)

Multifunctional: Cyclic disulfide liposomes have been developed for the dual purposes of enhancing cellular delivery through reaction with cell-surface thiols and facilitating liposome functionalization. These liposomes are depicted in the form of beach balls being lofted at their target cells: a scene of a warm day at the beach for a summertime issue of Chemistry—A European Journal. More information can be found in the Research Article by M. D. Best and co-workers (DOI: 10.1002/chem.202201164).

The increasing added mass of a bouncing ball

A sphere moving through a fluid has a larger inertia than one moving through a vacuum. This increase in the inertia from the fluid is known as the added mass. The added mass has a large effect on the acceleration of the sphere if the sphere has a low density, and if the sphere is near a solid boundary. These effects are studied here by measuring the acceleration due to gravity of beach balls, in air, as they bounce vertically on the floor. The measured accelerations are smaller when the ball is closer to the floor because the added mass is larger there. These measurements are used to calculate the added mass of a sphere as a function of distance from the floor. The results collapse to a curve that is independent of ball size, and generally agrees with the predictions for an ideal fluid.

Beach balls: Assessing frustration tolerance in young children using a computerized task

Frustration tolerance is a skill related to emotional regulation processes and is important insofar as it affects people's social relationships and even health. Low levels of frustration tolerance in children have been associated with a greater number of externalizing symptoms such as aggression or anger. Despite its importance, there are a limited number of tasks that attempt to evaluate this construct objectively. Therefore, the aim of our work was the design of a computerized task, programmed as a videogame in order to assess frustration tolerance in children from 6 to 10 years old. The results obtained showed that the test had a good internal consistency and could be useful as an objective measure of frustration tolerance in children. In line with the literature, our data have shown no influence of gender or laterality of participants during the task and only 7% of the frustration measure could be explained by the influence of participants' age. On the other hand, the performance of the participants during the task has allowed us to classify them into six groups according to their performance, namely Low/High Frustration, Low/High Performance and Low/High Reaction Time. This test would permit to compare participants' performance with their reference group but also with their own results, facilitating the obtention of an objective assessment of frustration tolerance in young children.

Assessment of Performance of Posidona oceanica (L.) as Biosorbent for Crude Oil-Spill Cleanup in Seawater.

The marine environment is constantly at risk of pollution by hydrocarbon spills that requires its cleanup to protect the environment and human health. Posidonia oceanica (L.) (PO) beach balls, which are characteristic of the Mediterranean Sea and abundant on the beaches, are used as biosorbent to remove hydrocarbons from the sea. The impact of several factors such as oil concentration, time sorption, and weight sorbent was investigated to determine the oil and water sorption capacity for raw and milled P. oceanica fibers. The study of kinetic models for initial crude oil concentration of 2.5, 5, 8.8, 10, 15, 20, 30, and 40 g/L revealed that crude uptake followed the pseudo-first-order model while, for isotherm models, the crude uptake onto the P. oceanica tended to fit the Langmuir model. Experiments were performed according to two systems: a pure oil and pure water system and a mixed oil/water system. For the dry system (pure oil and pure water), the maximum oil and water sorption capacity of raw and milled fibers was found to be 5.5 g/g and 14 g/g for oil and 14.95 g/g and 15.84 g/g for water, respectively, whereas, in the mixed oil/water system, the maximum oil and water sorption capacity was estimated as 4.74 g/g, 12.80 g/g and 7.41 g/g, 8.31 g/g, respectively. The results showed that, in spite of their absorbency of a lot of water, the milled fibers with grain size ranging between 0.5 mm and 1 mm might be the relevant sorbent for the elimination of crude oil from seawater thanks to its efficient sorption capacity and low cost.

Electrophysiological differences between typical and dense benign prostatic hyperplasia tissues retrieved after holmium laser enucleation of the prostate

Electrophysiological differences between typical and dense (beach ball) benign prostatic hyperplasia (BPH) tissues were investigated using a needle device with a micro-electrical impedance spectroscopy (µEIS) sensor. Ten pieces of typical BPH tissues and beach balls were collected from ten patients during the morcellation procedure of Holmium laser enucleation of the prostate. Their impedance was measured at a frequency range from 100 to 1 MHz using the µEIS-on-a-needle (µEoN). The impedance data (magnitude) were compared between the two tissue types and their correlation with the pathologic features was investigated. The mean magnitude of the beach balls tended to be larger than that of the typical BPH tissues at all investigated frequencies. Notably, significantly larger magnitudes were observed in the beach balls at the frequencies higher than 15.9 kHz (p ≤ 0.02). The variation of mean log-transformed magnitudes by frequency was significantly different between both tissue types (p < 0.001). The pathologic features of the beach balls presented pure stromal nodules of nodular hyperplasia, while the typical BPH tissues presented mixed epithelial-stromal nodules. The impedance difference between typical BPH tissues and beach balls is assumed to be attributed to the amount of their stromal content.

Visualizing effects of anisotropy on seismic moments and their potency-tensor isotropic equivalent

Radiation patterns of earthquakes contain important information on tectonic strain responsible for seismic events. However, elastic anisotropy may significantly impact these patterns. We systematically investigate and visualize the effect of anisotropy on the radiation patterns of microseismic events. For visualization, we use a vertical-transverse-isotropic (VTI) medium. We distinguish between two different effects: the anisotropy in the source and the anisotropy on the propagation path. Source anisotropy mathematically comes from the matrix multiplication of the anisotropic stiffness tensor with the source strain expressed by the potency tensor. We analyze this effect using the corresponding radiation pattern and the moment tensor decomposition. Propagation anisotropy mathematically comes from the deviation between the polarization and the propagation direction of a quasi P-wave in an anisotropic medium. We investigate both effects separately by either assuming the source to be anisotropic and the propagation to be isotropic or vice versa. We find that both effects have a significant impact on the radiation pattern of a pure-slip source. Finally, we develop an alternative visualization of source mechanisms by plotting beach balls proportional to their potency tensors. For this, we multiply the potency tensor with an isotropic elasticity tensor having the equivalent shear modulus [Formula: see text] and [Formula: see text]. In this way, we visualize the tectonic deformation in the source, independently of the rock anisotropy.

Studying 3D collisions with smartphones

This paper describes a conservation of momentum experiment using just smartphones and two beach balls, thus making the experimental study of this movement available to any classroom. For a more thorough analysis of the data, a computer can also be used. Experiments making use of smartphone sensors have been described before, contributing to an improved teaching of classical mechanics. In this experiment, we have made use of two smartphone cameras together with the VidAnalysis free app to track the position of two balls colliding in air during a projectile motion (Fig. 1).

Predictors of dense prostatic tissue (beach balls) during morcellation in HoLEP

Predictors of dense prostatic tissue (beach balls) during morcellation in HoLEP

Evaluation of a Laser Scanning Sensor in Detection of Complex-Shaped Targets for Variable-Rate Sprayer Development

<abstract> Sensors that can accurately measure canopy structures are prerequisites for development of advanced variable-rate sprayers. A 270° radial range laser sensor was evaluated for its accuracy in measuring the dimensions of target surfaces with complex shapes and sizes. An algorithm for data acquisition and three-dimensional (3-D) canopy image construction were designed and processed with an embedded computer. Test targets included three beach balls at three heights, a rectangular box, a cylinder, two artificial trees, and three field-grown ornamental trees. Other variables included 2, 3, 4, and 5 m detection distances and sensor travel speeds of 3.2, 4.8, 6.4, and 8.0 km h^-1. The laser sensor measurements of the test targets were statistically similar with the actual measurements. The average root mean square error (RMSE) and coefficient of variation (CV) varied slightly with detection distance and travel speed. Among all the dimension measurements in the ranges of 0.58 to 2.54 m in the X direction, 0.58 to 2.54 m in the Y direction, and 0.58 to 2.94 m in the Z direction, the highest average RMSE of 68 mm occurred in the Z direction and the highest average CV of 8.6% occurred in the Y direction. Similarity of paired images from the laser sensor and a camera was greater than 0.85 for all targets. These tests confirmed the capability of the laser sensor and the algorithm to accurately measure complex-shaped targets, offering potential for integration of the sensor and algorithm into sprayers that would make real-time adjustment of spray outputs to match plant structures and travel speeds.

Predictors of Enucleation and Morcellation Time During Holmium Laser Enucleation of the Prostate

To examine predictors of enucleation and morcellation times within a large cohort of men undergoing holmium laser enucleation of the prostate (HoLEP) for benign prostatic hypertrophy. Preoperative, perioperative, and postoperative clinical characteristics were available from men treated with HoLEP between 1998 and 2013 at Indiana University Health Methodist Hospital. Stepwise linear regression was performed to determine clinical variables which are associated with enucleation and morcellation times. We identified 960 patients who underwent HoLEP. Average (range) enucleation time was 65.7 (11-245) minutes and morcellation time was 19.7 (3-260) minutes. History of anticoagulation was associated with a small decrease in enucleation time (P=.013) whereas increasing HoLEP specimen weight was associated with increasing enucleation time (P<.001). History of intermittent catheterization, urinary tract infections (UTI), presence of dense prostatic tissue (colloquially referred to as "beach balls"), and increasing specimen weight were associated with increasing morcellation time (P<.05 each). Having HoLEP performed by a less experienced urologist was associated with longer enucleation and morcellation times. Prostate volume is significantly associated with increased enucleation and morcellation times during HoLEP. Additionally, history of UTI and clean intermittent catheterization (CIC) is associated with modest increases in enucleation and morcellation times. Dense enucleated prostate tissue significantly impacts the ability to morcellate effectively. Increasing surgeon experience can significantly improve both enucleation and morcellation efficiency.

Mystery beach balls foul Long Island, NY, beaches

Mystery beach balls foul Long Island, NY, beaches

Geology of the Brega area and the ichnofauna of the ‘Brega Sandstone Bed’ (Pliocene), Libya

The sandstone outcrops in the Brega Area Two are designated as ‘Brega Sandstone Bed’ on the basis of the lithological similarities and stratigraphy of the region surrounding Brega. The ‘Brega Sandstone Bed’ is considered to be equivalent to the lower part of the Member V of the Sahabi Formation of the Pliocene age. The thinly bedded greyish to greenish sandstone interbedded with gravel and pebble beds exposed at the ‘Sea cliff section’ represents the upper part of Member V of the Sahabi Formation. Outcrops of Pleistocene-cemented marine dunes belong to the Ajdabiya Formation and are seen as patches of marine dunes of various shapes, lengths and heights that run parallel to the modern day Mediterranean Sea coastline. The Holocene sediments around Brega include coastal and inland sand dunes and sand sheets mixed with millions of 'beach balls'. The ichnofaunal assemblage of the ‘Brega Sandstone Bed’ is dominated by various types of vertical, oblique and horizontal burrows that are branched and unbranched. They are dominated by ichnogenera Ophiomorpha and Skolithos. The ichnocoenose dominated by these two ichnogenera belong to the marine soft ground Skolithos ichnofacies. Lithology of the ‘Brega Sandstone Bed’ and its ichnocoenose indicate a shallow marine, intertidal to shallow subtidal, moderate to high energy depositional environments.

Numerical deflation of beach balls with various Poisson’s ratios: From sphere to bowl’s shape

We present a numerical study of the shape taken by a spherical elastic surface when the volume it encloses is decreased. For the range of 2D parameters where such a surface may model a thin shell of an isotropic elastic material, the mode of deformation that develops a single depression is investigated in detail. It occurs via buckling from sphere toward an axisymmetric dimple, followed by a second buckling where the depression loses its axisymmetry through folding along portions of meridians. For the thinnest shells, a direct transition from the spherical conformation to the folded one can be observed. We could exhibit unifying master curves for the relative volume variation at which first and second buckling occur, and clarify the role of Poisson's ratio. In the folded conformation, the number of folds and inner pressure are investigated, allowing us to infer shell features from mere observation and/or knowledge of external constraints.

Monkeys, beach balls, and Twinkies®: using analogies to teach enzyme kinetics

Traditionally, enzyme kinetics is taught by emphasizing the mathematics behind the kinetic equations. For example, students are shown how to derive and transform the Michaelis‐Menten equation and calculate Km, kcat, and Ki values from various plots. Many, if not most, students respond by memorizing formulas and using a “plug and chug” approach to solve kinetic problems. This is unfortunate, as the students never gain an appreciation of how the kinetic analysis relates to the catalytic mechanism. An alternative to the above method is to use analogies to emphasize the physical picture behind the mathematics. This latter method gets students out of their comfort zone by forcing them to connect the physical picture to the reaction mechanism and, ultimately, the mathematical analysis. Students gain an appreciation of where the kinetic equations come from and develop a more flexible approach to problem solving. By encouraging interaction between the students and teacher, the analogies make teaching more effective and learning more enjoyable. Monkeys eating peanuts (“peanutases”) and students opening beach ball valves (“beachballases”) are especially useful analogies for teaching concepts in enzyme kinetics, including the meaning of Km and kcat, saturation kinetics, and enzyme inhibition. As for Twinkies®, they are both a delicious snack and a great way to explain the difference between thermodynamics and kinetics.

Geological and geophysical modeling on virtual globes using KML, COLLADA, and Javascript

Keyhole Markup Language (KML) has become established as the universal standard for scientific research using virtual globes such as Google Earth and NASA World Wind. We use KML to render geological maps and link associated COLLADA models to represent data such as structural orientations, cross-sections, and geophysical moment tensor solutions. Many other geologists and geophysicists have draped digital maps over a virtual globe's terrain, but some have paid little attention to the problems of image file size and orientation conservation. To maintain application responsiveness and enhance interactivity, we have created data pyramids matching Google Earth's own image pyramids for terrain rendering. This is critical in areas of the world where the terrain is poorly rendered, such as our field areas in the west of Ireland. Following four weeks in the field, we constructed data pyramid structures by hand and coded KML to control data fade-in and blending. This resulted in geological maps that show content appropriate to the current level of detail as defined by the 〈Lod〉 tag in KML. Recent and current implementations of standard KML (versions 1.0 through 2.2) have limitations when it comes to mapping and modeling of subsurface geological and geophysical features. Initially, we overcame these limitations by rendering data in the style of seismic first motion "beach balls" hovering over their respective hypo-centers, and we developed KML code that permits COLLADA models to emerge from the subsurface using the Google Earth slider control. Our latest work includes subsurface views that are made possible by using the Google Earth application program interface (API) with multiple Javascript controls. The methods we have developed are applicable to a wide range of geological and geophysical mapping and modeling problems and have potential uses in both geoscience research and education.

Like Graceland

Like Graceland Sharon Pomerantz [Begin Page 91] Harrison Miller's wife stood in the shallow end of the pool surrounded by her admirers. From his chaise on the deck, Harrison could see the men's chests and shoulders, their heads bent toward her, faces expectant. Courtney wore a red bikini; her long dark hair was piled on top of her head and held in place with a large silver barrette, and her hands were on her hips. All five men towered over her, and she smiled slightly as she shifted her attention from one to the other, her eyes hidden behind enormous sunglasses. Then the tallest of the group, with the darkest, thickest head of hair, swooped down like a giant bird, picked up Harrison's wife, threw her over his [End Page 91] shoulder and carried her upstream. Shrieking, she pounded on his back, her legs fluttering in protest, but by the time they got to the middle of the pool, she was laughing. The man put her down in water that came up several inches above her waist; slowly he slid the strap of her bathing suit off one shoulder and then the other. Courtney pulled away her top, exposing her breasts—breasts that had nursed her daughter, breasts that for the last two and a half years had belonged only to her husband!—and flung the piece of fabric onto the cement so that it landed just a few feet away from Harrison. By then the pool was like a giant soup of breasts. Saggy ones with dark nipples, small, upturned ones that fit perfectly into a cupped hand and enormous silicone jobs, big and round and shiny as beach balls. Not everyone was young in that pool, some were close to Harrison's mother's age. She had left when he was eight, doubtless to frolic in just such a pool as this. If his father had volunteered to go with her on a few adventures, would she have stayed married to him? Might her fears, her depression, her sexual boredom, have been allayed? Surprising, Harrison thought, how public nudity rendered people oddly sexless, as if returning them to the nursery. He felt none of the excitement of conquest, of the hunt, that he had when he was single, sitting in a room of attractive young women who wore their clothing like camouflage, or weaponry. But the human body, as it pushed toward middle age and beyond—men in various stages of paunchiness, women with stretch marks and cellulite—was not meant for such careless exposure. Hadn't they all suffered enough? Harrison wore his bathing trunks but he did not go in the pool; neither did the woman in the chair next to him, who wore a voluminous yellow shift and big floppy yellow hat. From the bag at her feet emerged a never-ending supply of turquoise and brown yarn; she was knitting furiously and rarely looked up from her project, yet Harrison found her surprisingly aware of everything she did not look at, as if her eyes worked differently than other people's. She was Nancy Dawes, wife of Kevin Dawes, the man in the pool who'd carried off Harrison's wife. They were from Michigan—Battle Creek, she'd told Harrison the night before at dinner. Kevin worked for Kellogg, in product development. "You know, we could move to the clothed beach," Nancy said, still not looking up. "We'd fit in better over there anyway." "I'm getting tired," Harrison said. "Hot sun." Nancy placed her knitting in her lap and moved her chair a bit closer, examining Harrison's shoulder. She was a large woman, with short hair streaked several shades of blond, deep set gray eyes and a wide, prominent nose. "I think you're getting burned," she said. "Your skin's pink. Need any lotion?" [End Page 92] Harrison didn't answer; his attention was once more on Courtney, who was lifting herself out of the pool, both arms rigid...

Outside In - David Newnham tries to keep his mind off beach balls and watermelons

Outside In - David Newnham tries to keep his mind off beach balls and watermelons

Analytical Currents: Molecular interactions with beach balls

Analytical Currents: Molecular interactions with beach balls