How capillarity affects the propagation of elastic waves in soft gels.

Elastic waves propagating at the interface of soft solids can be altered by the presence of external forces such as capillarity and gravity. We measure the dispersion relation of waves at the free surface of agarose gels with great accuracy, revealing the existence of multiple modes as well as an apparent dispersion. We disentangle the role of capillarity and elasticity by considering the three-dimensional nature of mechanical waves, achieving quantitative agreement between theoretical predictions and experiments. Notably, our results show that capillarity plays an important role for wave numbers smaller than expected from balancing elastic and capillary forces. We further confirm the efficiency of our approach by including the effect of gravity in our predictions and quantitatively comparing it to experiments.

Endo-Urological Techniques for Benign Uretero-Ileal Strictures Have Poor Efficacy and Affect Renal Function.

INTRODUCTION: Uretero-ileal strictures (UES) following urinary diversion are therapeutically challenging. We compared the efficacy, safety and renal outcome following therapeutic endo-urological techniques (EUTs) and open surgical revision of the anastomosis (SRA) for UES. MATERIAL AND METHODS: We retrospectively analysed all EUTs and SRAs performed for UES in 2 hospitals between 1987 and 2015. Restenosis was defined as recurrent radiographically diagnosed hydronephrosis and re-intervention. Renal function (estimated glomerular filtration rate [eGFR]) decrease was correlated with the number of EUTs per patient. RESULTS: Eighty-five UES were treated with 105 EUTs and 31 open revisions. Due to total obstruction, 28 (27%) EUTs were aborted. During a median follow-up of 33 months, restenosis occurred following 53 out of 77 (69%) completed EUTs and 4 out of 31 (13%) SRAs (p < 0.001 on univariable and multivariable analyses). No serious (Clavien ≥3b) EUT-related complications occurred vs. 5 (19%) related to SRA (p < 0.001). The number of finalised EUTs was independently associated with eGFR loss (ß = 12.3 mL/min/1.73 m2 loss per EUT, p = 0.008), with a significant cutoff value of >1 EUTs. SRA did not affect renal function (ß = 6.8 mL/min/1.73 m2 loss, p = 0.276). CONCLUSIONS: Although EUTs are less invasive, they have an inferior efficacy to SRA. Our results suggest that a maximum of one EUT may be attempted without significantly compromising renal function.

Faraday wave lattice as an elastic metamaterial.

Metamaterials enable the emergence of novel physical properties due to the existence of an underlying subwavelength structure. Here, we use the Faraday instability to shape the fluid-air interface with a regular pattern. This pattern undergoes an oscillating secondary instability and exhibits spontaneous vibrations that are analogous to transverse elastic waves. By locally forcing these waves, we fully characterize their dispersion relation and show that a Faraday pattern presents an effective shear elasticity. We propose a physical mechanism combining surface tension with the Faraday structured interface that quantitatively predicts the elastic wave phase speed, revealing that the liquid interface behaves as an elastic metamaterial.

Políticas de acceso a la tierra rural y sostenibilidad ambiental comunidades agrarias sechina, la ensenada y cerro San Gil, Izabal, Guatemala / Rural land access policies and environmental sustainability agrarian communities sechina, la ensenada and cerro San Gil, Izabal, Guatemala

En Guatemala pocas temáticas son abordadas con tanta vehemencia, como el acceso, uso de la tierra y susimplicaciones sobre las relaciones sociales, laborales y recientemente ambientales. Las políticas agrarias delacceso a la tierra de los últimos 50 años, propiciadas por la Ley de Transformación Agraria y Ley del Fondo deTierras, si bien mitigaron la pobreza en el agro rural, en su conjunto conllevaron daños ambientales irreversiblesy deudas agrarias, comprometiendo la sostenibilidad ambiental de los procesos de producción agropecuarios enel país. Este estudio mediante técnicas de fotointerpretación analiza los cambios de uso de la tierra y coberturaboscosa, como expresión del desarrollo agropecuario en las comunidades agrarias Sechina, La Ensenada y CerroSan Gil, ubicadas en el departamento de Izabal y beneficiarias de la Ley de Transformación Agraria entre 1960hasta1999 y sus implicaciones al 2010, bajo la Ley del Fondo de Tierras. Se concluyó que bajo la premisa de“mejora a la tierra” de actividades agropecuarias, se produjo cambio de uso de la tierra, de forestal a agropecuarioen la comunidad Sechina 42%, La Ensenada 46.2% y Cerro San Gil 48.6%. Lo anterior conllevó al sobreuso delas tierras en 42, 78 y 30%, respectivamente; lo que comprometió la sostenibilidad del proceso agropecuario,generando degradación ambiental de carácter irreversible.

In Guatemala few themes are dealt with such strength, such as land use and access, and its implications on labor,social and environmental relations. Agricultural policies of access to rural land of the last 50 years, were propiciatedby Agrarian Transformation Law and the Land Fund Law, although mitigated poverty in the rural agro,entailed irreversible environmental damage compromising the environmental sustainability of agriculture productionprocesses in the country. This study by photointerpretation techniques analyzes the changes in land use and forestcover, as an expression of agricultural development in farming communities Sechina, La Ensenada and Cerro SanGil, located in the department of Izabal, and beneficiaries of the Agrarian Reform Law, between 1960 and 1999 andits implications to 2010, under the Land Fund Law. It was concluded that under the premise of “land improvement”of agricultural activities occurred change on land use from forestry to agriculture in the community Sechina 42%,La Ensenada 46.2% and Cerro San Gil 48.6%. This led to overuse of land in 42, 78 and 30%, respectively. Thisundermined the sustainability of the farming process, producing irreversible environmental degradation.

Aplicación del índice de calidad de suelos en plantaciones forestales de palo blanco (Tabebuia donnell-smithii Rose) y Matilisguate (Tabebuia rosea Bertol) en Guatemala / Application of the soil quality index in forest plantations of palo blanco (Tabebuia donnell-smithii Rose) y Matilisguate (Tabebuia rosea Bertol) in Guatemala

El desarrollo forestal y el manejo sostenible de los ecosistemas forestales se fundamentan en la forestación,propiciada por la Ley de Fomento al Establecimiento, Recuperación, Restauración, Producción y Protección deBosques en Guatemala, Probosques. Por lo que reviste importancia el conocimiento de las características edáficas de sitio que garanticen el establecimiento y desarrollo de las plantaciones forestales. Esta investigación presentauna aplicación del índice de calidad de suelos forestales (SQI) desarrollado por el Departamento de Agricultura yServicio Forestal de los Estados Unidos de América, para calificar sitios forestales con base en propiedades fisicoquímicas de los suelos. Se evaluaron 22 sitios forestales ubicados tanto en la parte norte como sur del país, con plantaciones jóvenes de palo blanco (Tabebuia donnell-smithii Rose) y matilisguate (Tabebuia rosea Bertol). Los sitios fueron categorizados en clase I (SQI = 90%); clase II (SQI = 75%); clase III (SQI = 70%); clase IV (SQI =65%) y clase V (SQI = 55%), lo anterior con objeto de describir condiciones edáficas de sitio, que contribuyan al éxito del establecimiento de plantaciones forestales en el país. Se concluye que el SQI es una herramienta práctica que permitió agrupar sitios en términos edafológicos, lo que puede utilizarse con múltiples fines para optimizar la productividad de las tierras forestales en el país.

Forestry development and sustainable management of forest ecosystems are based on forestry, organized bythe Law for the Promotion of Establishment, Recovery, Restoration, Production and Protection of Forests inGuatemala, called Probosques. Therefore, it is important to generate knowledge of edaphic site features, that ensure the establishment and growth of forest plantations. This research presents an application of the Soil Forest Quality Index (SQI) developed by the Department of Agriculture and Forest Service of the United States of America, to qualify forest sites based on physico-chemical soil properties. Twenty-two forest sites located on both the northand south of the country, with young plantations of white wood (Tabebuia donnell-smithii Rose) and Matilisguate(Tabebuia rosea Bertol) were evaluated. The sites were categorized into Class I (SQI = 90%); Class II (SQI = 75%);Class III (SQI = 70%); Class IV (SQI = 65%) and Class V (SQI = 55%), the above in order to describe edaphic siteconditions that contribute to the successful establishment of forest plantations in the country. It is concluded that the SQI is a practical tool that allowed group sites in pedological terms, which can be used for multiple purposesto optimize productivity of forest land in the country.

Universal spreading of water drops on complex surfaces.

A drop of water spreads very rapidly just after it is gently deposited on a solid surface. Here we experimentally investigate how these early stages of spreading are influenced by different types of surface complexity. In particular, we consider micro-textured substrates, chemically striped substrates and soft substrates. For all these complex substrates, it is found that there always exists an inertial regime where the radius r of the wetted area grows as r ∼ t(1/2). For perfectly wetting substrates, this regime extends over several decades in time, whereas we observe a deviation from a pure power-law for partially wetting substrates. Our experiments reveal that even the cross-over from the 1/2 power law to the final equilibrium radius displays a universal dynamics. This cross-over is governed only by the final contact angle, regardless of the details of the substrate.

Influence of droplet geometry on the coalescence of low viscosity drops.

The coalescence of water drops on a substrate is studied experimentally. We focus on the rapid growth of the bridge connecting the two drops, which very quickly after contact ensues from a balance of surface tension and liquid inertia. For drops with contact angles below 90°, we find that the bridge grows with a self-similar dynamics that is characterized by a height h~t(2/3). By contrast, the geometry of coalescence changes dramatically for contact angles at 90°, for which we observe h~t(1/2), just as for freely suspended spherical drops in the inertial regime. We present a geometric model that quantitatively captures the transition from 2/3 to 1/2 exponent, and unifies the inertial coalescence of sessile drops and freely suspended drops.

Primary urethral carcinoma in females: an epidemiologic study on demographical factors, histological types, tumour stage and survival.

PURPOSE: To obtain insight into demographical factors, histology and survival rates of females diagnosed with primary urethral cancer and to determine favourable treatment. METHODS: Data from 91 females with primary urethral carcinoma, age varying from 15 to 85 years, registered between 1989 and 2008 at the National Cancer Registry of the Netherlands were used for this study. Demographical factors, incidence rate, morphology and tumour stage according to TNM classification were analysed. Kaplan-Meier survival curves were constructed and stratified by stage, histological type and treatment modality. RESULTS: The overall crude annual incidence was 0.7 per million women with a peak incidence in the age group of 80-84 years. Analysis of the morphology showed urothelial cell carcinoma (UCC) in 45 %, squamous cell carcinoma (SCC) in 19 %, adenocarcinoma (AC) in 29 %, and unknown or undifferentiated carcinoma accounted for 6 %. Almost half of patients (46 %) had advanced disease at time of diagnosis and was mainly treated with surgery and/or radiotherapy. The 5-year survival rates of stage 0-II, stage III and stage IV were 67, 53 and 17 %, respectively. The 5-year survival rates of SCC, UCC and AC were 64, 61 and 31 %, respectively. CONCLUSIONS: Female primary urethral carcinoma is a rare condition, and the majority of patients were aged above 65 years. Almost half of patients have advanced disease upon diagnosis. TNM stage and histological type of disease are the most determining factors for survival. Extended surgery with or without radiotherapy seems to be the most favourable treatment. Awareness and early diagnosis are important to improve survival.

Symmetric and asymmetric coalescence of drops on a substrate.

The coalescence of viscous drops on a substrate is studied experimentally and theoretically. We consider cases where the drops can have different contact angles, leading to a very asymmetric coalescence process. Side view experiments reveal that the "bridge" connecting the drops evolves with self-similar dynamics, providing a new perspective on the coalescence of sessile drops. We show that the universal shape of the bridge is accurately described by similarity solutions of the one-dimensional lubrication equation. Our theory predicts that, once the drops are connected on a microscopic scale, the bridge grows linearly in time with a strong dependence on the contact angles. Without any adjustable parameters, we find quantitative agreement with all experiments.

Level splitting at macroscopic scale.

A walker is a classical self-propelled wave particle association moving on a fluid interface. Two walkers can interact via their waves and form orbiting bound states with quantized diameters. Here we probe the behavior of these bound states when setting the underlying bath in rotation. We show that the bound states are driven by the wave interaction between the walkers and we observe a level splitting at macroscopic scale induced by the rotation. Using the analogy between Coriolis and Lorentz forces, we show that this effect is the classical equivalent to Zeeman splitting of atomic energy levels.

The international prostate symptom score overestimates nocturia assessed by frequency-volume charts.

PURPOSE: We analyzed differences in nocturia, as estimated by the International Prostate Symptom Score and 7-day frequency-volume charts. MATERIALS AND METHODS: A total of 398 forms were collected from 500 consecutive urological outpatients willing to record a 7-day frequency-volume chart. All patients completed a general questionnaire, an International Prostate Symptom Score, and a bladder symptom and bother score. Missed recordings were indicated by a coded letter. Patients who lacked essential data, bedtimes or an International Prostate Symptom Score, or who recorded the frequency-volume chart for less than 5 days were excluded from study. RESULTS: A total of 186 men and 115 women with a mean age of 56 years were evaluable. In 10.6% of patients no nocturia occurred. Of those with nocturia 70% and 34% experienced nocturia a mean of 1 or more and 2 or more times, respectively. In 43% of patients the International Prostate Symptom Score equaled calculated categorized nocturia while 50% had a higher International Prostate Symptom Score nocturia score than calculated nocturia. On univariate analysis the correlation of International Prostate Symptom Score question 7 with mean nocturia increased with frequency-volume chart duration (day 1 r = 0.52 to day 3 r = 0.63). On longer duration frequency-volume charts the correlation showed no further increase. Multivariate regression analysis revealed that the nocturia score was determined by mean nocturia in the frequency-volume chart, the nocturia bother score and patient age. CONCLUSIONS: The International Prostate Symptom Score nocturia score overestimated nocturia in most patients, as derived from a 7-day frequency-volume chart. When scoring International Prostate Symptom Score nocturia question 7, patients included a degree of bother. The correlation of question 7 with mean nocturia increased with frequency-volume chart duration until day 3.

Unpredictable tunneling of a classical wave-particle association.

A droplet bouncing on a vibrated bath becomes a "walker" moving at constant velocity on the interface when it couples to the surface wave it generates. Here the motion of a walker is investigated when it collides with barriers of various thicknesses. Surprisingly, it undergoes a form of tunneling: the reflection or transmission of a given incident walker is unpredictable. However, the crossing probability decreases exponentially with increasing barrier width. This shows that this wave-particle association has a nonlocality sufficient to generate a quantumlike tunneling at a macroscopic scale.

Spiral patterns in the packing of flexible structures.

Spiral patterns are found to be a generic feature in close-packed elastic structures. We describe model experiments of compaction of quasi-1D sheets into quasi-2D containers that allow simultaneous quantitative measurements of mechanical forces and observation of folded configurations. Our theoretical approach shows how the interplay between elasticity and geometry leads to a succession of bifurcations responsible for the emergence of such patterns. Both experimental forces and shapes are also reproduced without any adjustable parameters.

A cross-sectional study of the international prostate symptom scores related to age and gender in Dutch adults reporting no voiding complaints.

OBJECTIVE: To determine the IPSS in a selected population reporting no voiding complaints. SUBJECTS AND METHODS: 1143 adults without voiding complaints were included. They were divided over both sexes and all decades. All subjects filled out questionnaires including the IPSS. Statistical analysis was aimed at relating the IPSS to age and gender. RESULTS: The IPSS in both sexes shows a gradual significant increase in consecutive age groups. Men in the third age decade have a mean score of 2.8, while men older than 70 years of age have a score of 7.0. In women these scores are 4.0 and 5.6 respectively. The increase is about equally caused by storage and voiding scores. The items addressing weak stream in men and nocturia and urgency in men and women are the major factors causing the correlation with age. Nearly 17% of all subjects have moderate symptom scores and 1% has severe scores. CONCLUSION: In both adult men and women reporting no voiding complaints the IPSS increases with age. This rise is more prominent in males.

[Enoxaparin in the prevention of deep venous thrombosis in general surgery]. / L'énoxaparine dans la prévention des thromboses veineuses profondes en chirurgie générale.

Because of their pharmacologic advantages Low Molecular Weight Heparins (LMWH) are more and more used in the prevention of deep venous thromboembolic disease. Among LMWH, enoxaparin (Lovenox Pharmuka) efficacy has been assessed in several clinical trials since 1986, including more than 10,000 patients. Two of them were carried out in patients undergoing general surgery. The first one was performed in 1988 by M Samama et al on about 800 patients which concluded that enoxaparin (in one 20 mg daily s.c. injection) was at least as effective as standard prophylaxis with Unfractionated Heparin (U H), (three 5,000 IU daily s.c. injections). Second trial, coordinated by S Haas in 1988 on more than 8000 patients confirmed safety and efficacy of enoxaparin in prevention of post-operative thrombosis. These trials corroborate those carried out in orthopaedic surgery with enoxaparin: efficacy at least as effective as UH, with only one daily s.c. injection; mild biologic follow up (particularly, coagulation tests are useless with usual doses); a same dosage for all patients (20 mg daily s.c. injection in general surgery and 40 mg daily in orthopaedic surgery) independent of patient's weight. This prescription has to be started 12 hours before surgery with 40 mg and 2 h before with 20 mg.