High order numerical methods for myxobacteria pattern formation

Rippling patterns of myxobacteria appear in starving colonies before they aggregate to form fruiting bodies. These periodic traveling cell density waves arise from the coordination of individual cell reversals, resulting from an internal clock regulating them, and from contact signaling during bacterial collisions. Our main interest in this research is the numerical approximation with high order accuracy in space of the solutions of mathematical models proposed for myxobacteria rippling. We revisit the studies of Igoshin et al [Proc. Natl. Acad. Sci, USA 98, 14913 (2001) and Phys. Rev. E 70, 041911 (2004)] which describe the rippling phenomena of myxobacteria as a system of hyperbolic conservation laws (when the di¤usion is zero). Since the solution of systems of conservation laws develops jump discontinuities in time and space, it is important to use accurate numerical simulators in order to explain and predict the natural biological process, which is our approach. Previously, patterns for this model were obtained only by numerical methods of low order of accuracy and it was not possible to find their wavenumber analytically.En las colonias hambrientas de myxobacteria aparecen patrones ondulatorios antes de que las bacterias se agreguen para formar cuerpos fructíferos. Estas ondas periódicas de densidad celular itinerante surgen como resultado de la coordinación de las reversiones celulares, a causa de un reloj interno, y por el contacto de señalización durante las colisiones bacterianas. Nuestro principal interés en esta tesis es la aproximación numérica con alta precisión para las soluciones de los modelos matemáticos propuestos para la ondulación de las myxobacterias. Revisamos los estudios de Igoshin y coautores [Proc. Natl. Acad. Sci, EE.UU. 98, 14913 (2001) y Phys. Rev. E 70, 041911 (2004)], que describen los patrones ondulatorios de myxobacterias como un sistema de leyes de conservación hiperbólica (cuando la difusión es cero). Teniendo en cuenta que las propiedades de la solución de sistemas de leyes de conservación desarrollan discontinuidades de salto y fuertes gradientes en el tiempo y el espacio, consideramos importante utilizar simuladores numéricos precisos con el .n de explicar y predecir el proceso biológico natural, que es nuestro enfoque. Anteriormente, las pautas de este modelo se obtuvieron solamente por métodos numéricos de orden de precisión inferior y no fue posible encontrar su número de onda de forma analítica.Programa Oficial de Posgrado en Ingeniería MatemáticaPresidente: Ana María Carpio Rodríguez.- Secretario: Manuel Carretero Cerrajero.- Vocal: Gloria Platero Coell

Burns in children and their treatment

Opekline kože jedne su od vrlo čestih povreda kod djece svih uzrasta, a jedne od najčešćih kod manje djece. Ovisno o načinu nastanka, površini zahvaćenosti i duljini kontakta s toplinskim izvorom, opekline ponekad dovode do velikih metaboličkih promjena i pojačanog neuroendogenog odgovora organizma, pa govorimo o opeklinskoj bolesti. Prema dubini opečene površine opekline svrstavamo u opekline I., II., III. i IV. stupnja. Osim dubine, procjena opeklinske bolesti ovisi i o zahvaćenoj površini. Za procjenu veličine opečene površine koriste se razna pravila ili sheme, modificirane za djecu, jer osim dijelove tijela uzimaju u obzir I godine starosti. Tako je, uzimajući u obzir specifičnosti dječje dobi, težina opeklina kod djece podijeljena u tri kategorije: lake, umjerene i teške. Opekline I. i II. stupnja uglavnom se liječe konzervativno, za razliku od opeklina III. stupnja koje zahtijevaju operativno liječenje, u cilju uklanjanja nekrotičnog tkiva. No potreba da se ekscizija učini do u zdravo najčešće dovodi do povećanja površine koju treba pokriti. Posljedično tome dolazi i do nastanka većih ožiljaka, što je još uvijek predmet brojnih istraživanja kad je u pitanju njihovo liječenje. Važno je, dakle, izbjeći kirurški debridman kod djece, naročito ako znamo da postoji razlika u dječjoj fiziologiji i patofiziologiji opeklinskih rana. Upravo stoga, imajući u vidu da djeca nisu “odrasli u malom”, opekline zahtijevaju i drugačiji pristup liječenja, o čemu se govori u ovom preglednom članku.Skin burns are among the most common injuries in children of all ages, and one of the most common in younger children. Depending on the mode of occurrence, area of involvement and length of contact with the heat source, burns sometimes lead to major metabolic changes and increased neuroendogenous response of the body, which is referred to as the “burn disease”. Depending on the depth of tissue damage, burns are categorized into four grades: I, II, III and IV. Except for the depth, the area of involvement is also very important in the estimation of the burn disease. The size of burn involvement is measured by using various rules and schemes that are modified for children, taking into consideration not only the different parts of the body but also the age of the child. Altogether, burn wounds in children are clinically divided into three categories: mild, moderate and heavy. The grade I and II burns are mostly treated conservatively, whereas those of grade III need surgical treatment in order to remove the necrotic tissue. Surgical excision up to the normal tissue very often produces a larger area that should be replaced. As a consequence, the scars are larger and their treatment is still a subject of numerous research studies. It is very important to avoid surgical debridement in children, especially because the physiology and pathophysiology of the burns’ wound in children are different. Thus, burns in children have their own specificities and, considering that children are not “adults in a small”, require a different approach to treatment, which is discussed in this article

Successful Use of Silver Impregnated Hydrofiber Dressing in the Treatment of Kerion Celsi Caused by Microsporum gypseum

A method of treatment of tinea capitis is presented in the case of a 10-year-old boy who was referred to the pediatric surgical unit for the treatment of a skin lesion on the scalp which had persisted for more than two months. The initial dermatological examination led to the clinical diagnosis of inflammation of the scalp, while mycological analysis revealed an uncommon dermatophyte agent, Microsporum gypseum, in the culture. The lesion was subsequently treated with local and oral antifungal agents, but the antifungal therapy was discontinued due to developed liver dysfunction and replaced with treatment using a silver impregnated hydrofiber dressing. During one month of follow-up, the patient\u27s scalp lesion cleared completely. The treatment of tinea capitis is discussed.</p

Burns in children and their treatment

Opekline kože jedne su od vrlo čestih povreda kod djece svih uzrasta, a jedne od najčešćih kod manje djece. Ovisno o načinu nastanka, površini zahvaćenosti i duljini kontakta s toplinskim izvorom, opekline ponekad dovode do velikih metaboličkih promjena i pojačanog neuroendogenog odgovora organizma, pa govorimo o opeklinskoj bolesti. Prema dubini opečene površine opekline svrstavamo u opekline I., II., III. i IV. stupnja. Osim dubine, procjena opeklinske bolesti ovisi i o zahvaćenoj površini. Za procjenu veličine opečene površine koriste se razna pravila ili sheme, modificirane za djecu, jer osim dijelove tijela uzimaju u obzir I godine starosti. Tako je, uzimajući u obzir specifičnosti dječje dobi, težina opeklina kod djece podijeljena u tri kategorije: lake, umjerene i teške. Opekline I. i II. stupnja uglavnom se liječe konzervativno, za razliku od opeklina III. stupnja koje zahtijevaju operativno liječenje, u cilju uklanjanja nekrotičnog tkiva. No potreba da se ekscizija učini do u zdravo najčešće dovodi do povećanja površine koju treba pokriti. Posljedično tome dolazi i do nastanka većih ožiljaka, što je još uvijek predmet brojnih istraživanja kad je u pitanju njihovo liječenje. Važno je, dakle, izbjeći kirurški debridman kod djece, naročito ako znamo da postoji razlika u dječjoj fiziologiji i patofiziologiji opeklinskih rana. Upravo stoga, imajući u vidu da djeca nisu “odrasli u malom”, opekline zahtijevaju i drugačiji pristup liječenja, o čemu se govori u ovom preglednom članku.Skin burns are among the most common injuries in children of all ages, and one of the most common in younger children. Depending on the mode of occurrence, area of involvement and length of contact with the heat source, burns sometimes lead to major metabolic changes and increased neuroendogenous response of the body, which is referred to as the “burn disease”. Depending on the depth of tissue damage, burns are categorized into four grades: I, II, III and IV. Except for the depth, the area of involvement is also very important in the estimation of the burn disease. The size of burn involvement is measured by using various rules and schemes that are modified for children, taking into consideration not only the different parts of the body but also the age of the child. Altogether, burn wounds in children are clinically divided into three categories: mild, moderate and heavy. The grade I and II burns are mostly treated conservatively, whereas those of grade III need surgical treatment in order to remove the necrotic tissue. Surgical excision up to the normal tissue very often produces a larger area that should be replaced. As a consequence, the scars are larger and their treatment is still a subject of numerous research studies. It is very important to avoid surgical debridement in children, especially because the physiology and pathophysiology of the burns’ wound in children are different. Thus, burns in children have their own specificities and, considering that children are not “adults in a small”, require a different approach to treatment, which is discussed in this article

The polymorphisms in Toll-like receptor genes and cancer risk

Toll-like receptors (TLRs) are a family of pattern recognition receptors and have important role in pathogen recognition including activation of innate and acquired immune responses. They are mainly expressed in epithelium but have also been found in cancer cells, where they can have pro-tumorigenic and anti-tumorigenic effect. Single nucleotide polymorphisms (SNPs) may change protein structure and influence receptor function. Polymorphisms in TLR genes have been linked with various cancer types and reports were often contradictory. The strongest association with increased cancer risk was found for TLR2 polymorphism –196 to –174 del (Δ22) (gastric, gallbladder and cervical cancer) and TLR4 polymorphisms rs4986790 (gastrointestinal cancers and lymphoma) and rs4986791 (gastrointestinal cancers, nasopharyngeal and gallbladder cancer). Other polymorphisms associatedwith cancer risk includeTLR10-TLR1-TLR6 gene cluster polymorphisms rs10008492 (non-Hodgkin’s lymphoma) and rs7696175 (breast cancer), TLR6 rs5743815 (non-Hodgkin’s lymphoma), TLR10 rs11466657 (meningioma), TLR2 GT microsatellite repeat number polymorphism (colorectal cancer) and rs3804100 (MALT lymphoma), TLR3 829A>C (nasopharyngeal cancer), TLR4 11350G>C (nasopharyngeal cancer), rs1927911 and rs10759931 (prostate cancer), TLR5 rs5744174 (gastric cancer) and TLR9 rs5743836 (Hodgkin’s lymphoma) and rs352140 (Hodgkin’s lymphoma and cervical cancer). Discrepancies in results of different studies regarding TLR polymorphisms and cancer risk may have arissen due to insufficient sample size, differences in ethnicity or age, undetected infections or other environmental factors

Rapid fabrication of pressure-driven open-channel microfluidic devices in omniphobic RF paper

This paper describes the fabrication of pressure-driven, open-channel microfluidic systems with lateral dimensions of 45-300 microns carved in omniphobic paper using a craft-cutting tool. Vapor phase silanization with a fluorinated alkyltrichlorosilane renders paper omniphobic, but preserves its high gas permeability and mechanical properties. When sealed with tape, the carved channels form conduits capable of guiding liquid transport in the low-Reynolds number regime (i.e. laminar flow). These devices are compatible with complex fluids such as droplets of water in oil. The combination of omniphobic paper and a craft cutter enables the development of new types of valves and switches, such as “fold” valves and “porous switches,” which provide new methods to control fluid flow.Chemistry and Chemical Biolog

Infekcija parazitom dirofilaria repens u desetogodišnjeg dječaka u Istri: prikaz slučaja

Dirofilariasis is a zoonotic infection caused by worms belonging to the genus Dirofilaria. The disease is transmitted by mosquitoes and the hosts are usually dogs. Infections in humans are rare and they usually manifest as a subcutaneous nodule or a conjunctival form. We present a 10-year-old boy with a subcutaneous nodule on his left forearm, who was admitted to the hospital. On examination, the only significant findings were high levels of eosinophils. The pediatrician suspected dirofilariasis and the boy was referred to pediatric surgery. The whole lesion was surgically removed and histopathologic examination confirmed parasitic infection by Dirofilaria repens. Although human dirofilariasis is a rare disease, the number of reported cases has recently increased worldwide. The disease mainly occurs in southern European countries, but has also been described in eastern Europe, Central Asia and Sri Lanka. Croatia is one of the endemic areas for dirofilariasis, especially in the region of the Istria Peninsula. The case presented highlights the requirement for further monitoring of endemic areas in order to establish effective preventive measures.Dirofilarijaza je zoonoza uzrokovana crvima koji pripadaju rodu Dirofilaria. Bolest prenose komarci, a uobičajeni domaćini su psi. Infekcije ljudi su rijetke i najčešće se očituju kao potkožni čvor ili kao konjunktivan oblik. Prikazuje se slučaj 10-godišnjeg dječaka koji je zaprimljen u bolnicu sa subkutanim čvorom na lijevoj podlaktici. Jedini značajniji nalaz su bile povišene vrijednosti eozinofila u krvi. Pedijatar je posumnjao na dirofilarijazu i dječak je upućen na dječju kirurgiju. Lezija je kirurški u cijelosti odstranjena i patohistološki je potvrđena parazitna infekcija, Dirofilaria repens. Unatoč tome što je ljudska dirofilarijaza rijetka bolest, broj zabilježenih slučajeva je u porastu u cijelom svijetu. Bolest se uglavnom javlja u zemljama južne Europe, ali je opisana i u istočnoj Europi, Centralnoj Aziji i Šri Lanki. Hrvatska je također jedno od endemskih područja za dirofilarijazu, osobito dijelovi Istarskog poluotoka. Prikazanim slučajem želi se istaknuti važnost praćenja endemskih područja kako bi se eventualno potaknulo uvođenje preventivnih mjera

Soft Actuators and Robots that Are Resistant to Mechanical Damage

This paper characterizes the ability of soft pneumatic actuators and robots to resist mechanical insults that would irreversibly damage or destroy hard robotic systems—systems fabricated in metals and structural polymers, and actuated mechanically—of comparable sizes. The pneumatic networks that actuate these soft machines are formed by bonding two layers of elastomeric or polymeric materials that have different moduli on application of strain by pneumatic inflation; this difference in strain between an extensible top layer and an inextensible, strain-limiting, bottom layer causes the pneumatic network to expand anisotropically. While all the soft machines described here are, to some extent, more resistant to damage by compressive forces, blunt impacts, and severe bending than most corresponding hard systems, the composition of the strain-limiting layers confers on them very different tensile and compressive strengths.Chemistry and Chemical BiologyOther Research Uni

Coated and uncoated cellophane as materials for microplates and open-channel microfluidics devices

This communication describes the use of uncoated cellophane (regenerated cellulose films) for the fabrication of microplates, and the use of coated cellophane for the fabrication of open-channel microfluidic devices. The microplates based on uncoated cellophane are particularly interesting for applications that require high transparency in the ultraviolet (UV) regime, and offer a low-cost alternative to expensive quartz-well plates. Uncoated cellophane is also resistant to damage by various solvents. The microfluidic devices, based on coated cellophane, can have features with dimensions as small as 500 μm, and complex, non-planar geometries. Electrodes can be printed on the surface of the coated cellophane, and embedded in microfluidic devices, to develop resistive heaters and electroanalytical devices for flow injection analysis, and continuous flow electrochemiluminescence (ECL) applications. These open-channel devices are appropriate for applications where optical transparency (especially in the visible regime), resistance to damage by water, biocompatibility and biodegradability are important. Cellophane microfluidic systems complement existing cellulose-based paper microfluidic systems, and provide an alternative to other materials used in microfluidics, such as synthetic polymers or glass. Cellulose films are plausible materials for uses in integrated microfluidic systems for diagnostics, analyses, cell-culture, and MEMS.Chemistry and Chemical Biolog