Grazing and control of coral reef community structure by Diadema antillarum Philippi (Echinodermata: Echinoidea): A preliminary study

The grazing activities of the tropical echinoid Diadema antillarum Philippi can markedly influence the structure of the shallow-water epibenthic coral reef community. The elimination of an entire Diadema population from a patch reef in St. Croix, U.S. Virgin Islands resulted in a great increase in macro-algal biomass, alterations in species composition, shifts in dominance, an increase in species numbers, and a decrease in equitability...

Identification of D179H, a novel missense GJB2 mutation in a Western Sicily family

The main purpose of this study was to describe a novel missense mutation (p.D179H) found in a Western Sicily family and to examine the genetic and audiologic profiles of all family members by performing a GJB2 and GJB6 mutations analysis and a complete audiologic assessment. The proband was a 3-month-old infant with a congenital profound sensorineural hearing loss; direct sequencing of the GJB2 revealed the presence of a c.35delG mutation in the heterozygous state and a heterozygous G[C transition at nucleotide 535 in trans; this novel mutation, called p.D179H, resulted in an aspartic acid to histidine change at codon 179. It was also evidenced in the heterozygous state in two members of this family, both with normal hearing. No GJB6 mutations were evidenced in all subjects studied. Considering the genotypic and phenotypic analysis of all family members, we suggest, differently from the p.D179 N mutation previously reported, a recessive mode of inheritance. Functional studies on p.D179H have to be performed to confirm our hypothesis

Theory of the synchronous motion of an array of floating flap gates oscillating wave surge converter

We consider a finite array of floating flap gates oscillating wave surge converter (OWSC) in water of constant depth. The diffraction and radiation potentials are solved in terms of elliptical coordinates and Mathieu functions. Generated power and capture width ratio of a single gate excited by incoming waves are given in terms of the radiated wave amplitude in the far field. Similar to the case of axially symmetric absorbers, the maximum power extracted is shown to be directly proportional to the incident wave characteristics: energy flux, angle of incidence and wavelength. Accordingly, the capture width ratio is directly proportional to the wavelength, thus giving a design estimate of the maximum efficiency of the system. We then compare the array and the single gate in terms of energy production. For regular waves, we show that excitation of the out-of-phase natural modes of the array increases the power output, while in the case of random seas we show that the array and the single gate achieve the same efficiency

The optimal design of a flap gate array in front of a straight vertical wall: Resonance of the natural modes and enhancement of the exciting torque

We consider a wave energy converter made of an array of Q neighbouring floating flap gates with finite thickness in front of a straight vertical wall in constant depth. Solutions of the radiation and scattering problems are achieved by application of Green's theorem and Green's function yielding a system of hypersingular integral equations for the velocity potential expanded in terms of Legendre polynomials. We investigate how the distance between the array and the vertical wall affects the performance of the array under the action of monochromatic and random waves. We show that large values of the exciting torque on the gates can be obtained by tuning the wall distance with the resonance of the natural modes of the array; this in turn yields large power extraction for a wide range of frequencies

Heat-transfer analysis of microfabricated thermocapillary pumping and reaction devices

A heat-transfer analysis was performed on thermocapillary pumping, a surface-tension-based drop pumping mechanism. The analysis, which incorporates both fluid flow and energy transport through multiple device layers, reveals effective material, design, and operational choices that result in improved pumping performance. Important design factors include thermal conductivity, channel/substrate thickness, and the velocity of the liquid drops. Results for pumping a drop of water on a fused silica substrate with a glass channel show that uniform interface temperatures can be achieved with bottom heating as long as drop velocities remain below ~0.1 cm s-1 . The analysis was also extended to include thermal reaction channels. The reactor analysis verified that relatively uniform reaction temperatures were attainable with bottom heating as long as channel heights were below ~100 µm.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49025/2/jm0107.pd

Weakly nonlinear theory for a gate-type curved array in waves

We analyse the effect of gate surface curvature on the nonlinear behaviour of an array of gates in a semi-infinite channel. Using a perturbation-harmonic expansion, we show the occurrence of new detuning and damping terms in the Ginzburg-Landau evolution equation, which are not present in the case of flat gates. Unlike the case of linearised theories, synchronous excitation of trapped modes is now possible because of interactions between the wave field and the curved boundaries at higher orders. Finally, we apply the theory to the case of surging wave energy converters (WECs) with curved geometry and show that the effects of nonlinear synchronous resonance are substantial for design purposes. Conversely, in the case of subharmonic resonance we show that the effects of surface curvature are not always beneficial as previously thought

Weakly nonlinear theory for oscillating wave surge converters in a channel

We present a weakly nonlinear theory on the natural modes' resonance of an array of oscillating wave surge converters (OWSCs) in a channel. We first derive the evolution equation of the Stuart-Landau type for the gate oscillations in uniform and modulated incident waves and then evaluate the nonlinear effects on the energy conversion performance of the array. We show that the gates are unstable to side-band perturbations so that a Benjamin-Feir instability similar to the case of Stokes' waves is possible. The non-autonomous dynamical system presents period doubling bifurcations and strange attractors. We also analyse the competition of two natural modes excited by one incident wave. For weak damping and power take-off coefficient, the dynamical effects on the generated power of the OWSCs are investigated. We show that the occurrence of subharmonic resonance significantly increases energy production

Genetic tools discriminate strains of leishmania infantum isolated from humans and dogs in Sicily, Italy

Background Leishmaniasis is one of the most important vector-borne diseases and it represents a seri-ous world health problem affecting millions of people. High levels of Leishmania infections, affecting both humans and animals, are recognized among Italian regions. Among these, Sicily has one of the highest prevalence of Leishmania infection. Methodology/Principal Findings Seventy-eight Leishmania strains isolated from human and animal samples across Sicily, were analyzed for the polymorphic k26-gene and genotypes were assigned according to the size of the PCR products. A multilocus microsatellite typing (MLMT) approach based on the analysis of 11 independent loci was used to investigate populations structure and genetic diversity of the isolated strains. Six L. infantum reference strains were included in the analysis for comparison. Bayesian clustering analysis of microsatellite data showed that all the isolated strains clustered in two genetically distinct populations, corresponding to human and canine isolates respectively. A further subdivision was observed between the two main groups, giving a good correlation between human strains and their geographic origin, conversely canine population showed a great genetic variability diffused in the territory. Conclusions/Significance Among the 78 Leishmania isolates, K26 analysis detected 71 samples (91%) as MON-1 zymodeme, confirming it as the predominant strain in Mediterranean area and 7 human samples (9%) as non-MON-1. MLMT gives important insights into the epidemiology of leish-maniases and allows characterization of different strains to a higher resolution than possible with zymodeme typing. Two main populations presented a strong correlation respect to the different hosts, exhibiting a co-circulation of two distinct populations of L. infantum. The population found in infected humans exhibited a correlation with geographic origin. These clusters could represent a geographically restricted population of strains with the same or related genotypes. This study can contribute to an understanding of Leishmania epidemiol-ogy, including the spread of reservoirs and sand fly vectors in the different foci of infection, characterizing parasites within the different hosts

Endoscopic Pilonidal Sinus Treatment. A Tertiary Care Academic Center Experience

Background: Pilonidal disease (PD) represents one of the most common proctological diseases in young adults. Although several approaches to treating PD have been described, there is still a lack of agreement on which is the best. The aim of this study was to evaluate the long-term efficacy of endoscopic pilonidal sinus treatment (EPSiT) at a tertiary care academic center. Methods: Between June 2017 and January 2021, a total of 32 patients [12 women (37.5%) and 20 men (62.5%)] with a mean age of 29.22 ± 12.98 years were treated with EPSiT. Pre- and post-operative symptoms were assessed with a score of 0–5. Success was defined as the absence of any subjective symptoms, as well as by complete post-operative wound healing. Results: Most of the patients had a midline external opening (17/32; 53.1%), with a mean number of external openings of 2.41 (1–4) ± 1.04. The median post-operative pain score was 0, and the mean follow-up period was 22 (4–42) ± 11.49 months. The time to wound healing was reduced in patients with one opening (28.14 ± 4.06 days) compared to patients with two or more openings (33.64 ± 7.3 days) (p = 0.067). The mean operative time was longer in patients who subsequently had a recurrence (41.75 ± 6.24 vs. 34.18 ± 6.24 min; p = 0.031). The overall success rate was 87.5% (28/32), and the mean time to recurrence was 3.25 (2–5) ± 1.26 months. Conclusions: EPSiT represents a viable option for the treatment of PD. More evidence and a longer follow-up period are needed to validate the results