Spatial analysis and risk mapping of Fasciola hepatica infection in dairy cattle at the Peruvian central highlands.

This study aimed to develop maps for Fasciola hepatica infection occurrence in dairy cattle in the districts of Matahuasi and Baños in the Peruvian central highlands. For this, a model based on the correlation between environmental variables and the prevalence of infection was constructed. Flukefinder® coprological test were performed in samples from dairy cattle from 8 herds, during both the rainy and wet season. Grazing plots were geo-referenced to obtain information on environmental variables. Monthly temperature, monthly rainfall, elevation, slope, normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), normalized difference water index (NDWI), distance to rivers, urban areas and roads were obtained by using remote sensor images and ArcGIS®. Multilayer perceptron Artificial Neural Networks modeling were applied to construct a predictive model for the occurrence of fasciolosis, based on the relationship between environmental variables and level of infection. Kappa coefficient (k > 0.6) was used to evaluate concordance between observed and forecasted risk by the model. Coprological results demonstrated an average prevalence from 20% to 100%, in Matahuasi, and between 0 and 87.5%, in Baños. A model with a high level of concordance between predicted and observed infection risk (k = 0.77) was obtained, having as major predicting variables: slope, NDWI, NDVI and EVI. Fasciolosis risk was categorized as low (p < 20%), medium (20% < p < 50%) and high (p ≥ 50%) level. Using ArcGIS 10.4.1, risk maps were developed for each risk level of fasciolosis. Maps of fasciolosis occurrence showed that 87.2% of Matahuasi area presented a high risk for bovine fasciolosis during the dry season, and 76.6% in the wet season. In contrast, 21.9% of Baños area had a high risk of infection during the dry season and 12.1% during the wet season. In conclusion, our model showed areas with high risk for fasciolosis occurrence in both districts during both dry and rainy periods. Slope, NDWI, NDVI and EVI were the major predictors for fasciolosis occurrence.

Accelerated annealing of fused filament fabricated (FFF) thermoplastics via an improved core-shell filament.

Thermoplastic parts manufactured via fused filament fabrication (FFF) have limited strength and toughness compared to other types of polymer additive and subtractive manufacturing. Low strength results from poor interlayer adhesion, making FFF parts not suitable for most engineering applications. Post processing solutions, such as annealing, enable healing of these interlayers, thus approaching injection molded parts. Prior work demonstrated a core-shell polycarbonate (PC)-acrylonitrile butadiene styrene (ABS) structured dual material filament to provide thermo-structural stability during annealing of the ABS component; however, annealing was limited to relatively low temperatures (135 °C) and required long annealing times (72 h). In the current work, a PC copolymer with a higher glass transition temperature (173 °C) than conventional PC is processed along with an extrusion-grade ABS into a PC-ABS core-shell filament. This improved dual material filament was printed, annealed, and evaluated via Izod impact testing, ultimately yielding 83% of bulk annealed ABS z-direction strength at an accelerated annealing time (8 h) and higher annealing temperature (155-175 °C). A demonstration part is printed with the dual material filament and annealed at 155 °C for 8 h, resulting in excellent dimensional accuracy, and a ductile failure at 73% higher ultimate load compared to the brittle failure of an as-printed part. This work highlights that material selection and design of a bicomponent filament geometry can lead to parts printed with FFF, with increased strength compared to other post-processing techniques at reduced processing times.

REVIEW OF DIOCTOPHYME RENALE: ETIOLOGY, MORPHOLOGY, BIOLOGY, ECOEPIDEMIOLOGY, PATHOGENESIS, SYMPTOMATOLOGY, DIAGNOSIS, TREATMENT, AND PREVENTION.

Dioctophyme renale has a worldwide distribution and has been diagnosed in several wild and domestic animals as well as in humans. As numerous reports in the literature exist concerning the presence of D. renale in different animal species, as well as its diagnosis, treatment, and confirmation in new geographic areas, we reviewed existing information to contribute to the knowledge of the etiology, biology, epidemiology, pathogenesis, symptoms, diagnosis, treatment, and prevention of D. renale. Results of dioctophymosis may range from asymptomatic infection to even death of the host. Diagnosis is based on data from morphology, imaging, and antibody testing, with surgical treatment being the most effective. A high potential for infection of pets exists when there is overlap with wild parasitized animals; given common risk factors for infections in humans, D. renale should be considered as having zoonotic potential.

Irreversible synthesis of an ultrastrong two-dimensional polymeric material.

Polymers that extend covalently in two dimensions have attracted recent attention1,2 as a means of combining the mechanical strength and in-plane energy conduction of conventional two-dimensional (2D) materials3,4 with the low densities, synthetic processability and organic composition of their one-dimensional counterparts. Efforts so far have proven successful in forms that do not allow full realization of these properties, such as polymerization at flat interfaces5,6 or fixation of monomers in immobilized lattices7-9. Another frequently employed synthetic approach is to introduce microscopic reversibility, at the cost of bond stability, to achieve 2D crystals after extensive error correction10,11. Here we demonstrate a homogenous 2D irreversible polycondensation that results in a covalently bonded 2D polymeric material that is chemically stable and highly processable. Further processing yields highly oriented, free-standing films that have a 2D elastic modulus and yield strength of 12.7 ± 3.8 gigapascals and 488 ± 57 megapascals, respectively. This synthetic route provides opportunities for 2D materials in applications ranging from composite structures to barrier coating materials.

[Enteroparasitosis in Peru and its relation to the Human Development Index]. / Enteroparasitosis en Perú y su relación con el Índice de desarrollo humano.

BACKGROUND: Diseases related to enteroparasites are a serious public health problem. OBJECTIVE: To assess the prevalence of enteroparasites in Peru and its relationship with the Human Development Index (HDI). MATERIAL AND METHODS: A coproparasitological study using the direct method from children and adults from the communities of Pamplona Alta in Lima, the province of San Sebastián de Quera, Castillo Grande, Pillco Marca and Puelles in Huánuco, Llupa-Huaraz in Ancash, and Machaguay in Arequipa, Peru, was carried out from 2012 to 2016. RESULTS: 864 samples were analyzed, and a total prevalence of 23.03% (199 cases) was found. The non-pathogenic protozoan Entamoeba coli, with 10.42% (90 cases), and the nematode Ascaris lumbricoides, with 6.37% (55 cases), were the most prevalent. PERMANOVA analysis based on the prevalences of enteroparasites in urban and rural areas of Peru showed differences among communities. The overall prevalence of urban communities was similar to that of the rural ones. CONCLUSIONS: Enteroparasitosis in Peru are not related to HDI. However, the levels of infestation by enteroparasites varied between the different communities, and they were related to the bioecological characteristics of parasites.

INTRODUCCIÓN: las enfermedades relacionadas con enteroparásitos son un grave problema de salud pública. OBJETIVO: evaluar la prevalencia de enteroparásitos en el Perú y su relación con el Índice de desarrollo humano (IDH). MATERIAL Y MÉTODOS: se realizó un estudio coproparasitológico por el método directo en niños y adultos de las comunidades de Pamplona Alta en Lima, de la provincia de San Sebastián de Quera, Castillo Grande, Pillco Marca y Puelles en Huánuco, Llupa-Huaraz en Ancash y Machaguay en Arequipa, Perú, de 2012 a 2016. RESULTADOS: se analizaron 864 muestras y se encontró una prevalencia total del 23.03% (199 casos). El protozoario no patógeno Entamoeba coli con 10.42% (90 casos) y el nematodo Ascaris lumbricoides con 6.37% (55 casos) fueron los más prevalentes. La prevalencia de protozoos fue mayor que la de los helmintos. No se observó asociación entre el IDH frente a la prevalencia total ni frente a las cuatro especies de enteroparásitos más frecuentes. El análisis PERMANOVA a partir de las prevalencias de enteroparásitos en áreas urbanas y rurales de Perú mostró diferencias entre las comunidades. La prevalencia total de las comunidades urbanas fue similar a la de las rurales. CONCLUSIONES: la enteroparasitosis en el Perú no se relaciona con el IDH. Sin embargo, los niveles de infestación por enteroparásitos variaron entre las diferentes comunidades y se relacionaron con las características bioecológicas de los parásitos.

Enteroparasitosis en Perú y su relación con el Índice de desarrollo humano / Enteroparasitosis in Peru and its relation to the Human Development Index

Introducción: las enfermedades relacionadas con enteroparásitos son un grave problema de salud pública. Objetivo: evaluar la prevalencia de enteroparásitos en el Perú y su relación con el Índice de desarrollo humano (IDH). Material y métodos: se realizó un estudio coproparasitológico por el método directo en niños y adultos de las comunidades de Pamplona Alta en Lima, de la provincia de San Sebastián de Quera, Castillo Grande, Pillco Marca y Puelles en Huánuco, Llupa-Huaraz en Ancash y Machaguay en Arequipa, Perú, de 2012 a 2016. Resultados: se analizaron 864 muestras y se encontró una prevalencia total del 23.03% (199 casos). El protozoario no patógeno Entamoeba coli con 10.42% (90 casos) y el nematodo Ascaris lumbricoides con 6.37% (55 casos) fueron los más prevalentes. La prevalencia de protozoos fue mayor que la de los helmintos. No se observó asociación entre el IDH frente a la prevalencia total ni frente a las cuatro especies de enteroparásitos más frecuentes. El análisis PERMANOVA a partir de las prevalencias de enteroparásitos en áreas urbanas y rurales de Perú mostró diferencias entre las comunidades. La prevalencia total de las comunidades urbanas fue similar que la de las rurales. Conclusiones: la enteroparasitosis en el Perú no se relaciona con el IDH. Sin embargo, los niveles de infestación por enteroparásitos variaron entre las diferentes comunidades y se relacionaron con las características bioecológicas de los parásitos.

Background: Diseases related to enteroparasites are a serious public health problem. Objective: To assess the prevalence of enteroparasites in Peru and its relationship with the Human Development Index (HDI). Material and methods: A coproparasitological study using the direct method from children and adults from the communities of Pamplona Alta in Lima, the province of San Sebastián de Quera, Castillo Grande, Pillco Marca and Puelles in Huánuco, Llupa-Huaraz in Ancash, and Machaguay in Arequipa, Peru was carried out from 2012 to 2016. Results: 864 samples were analyzed, and a total prevalence of 23.03% (199 cases) was found. The non-pathogenic protozoan Entamoeba coli, with 10.42% (90 cases), and the nematode Ascaris lumbricoides, with 6.37% (55 cases), were the most prevalent. PERMANOVA analysis based on the prevalences of enteroparasites in urban and rural areas of Peru showed differences among communities. The overall prevalence of urban communities was similar to that of rural ones. Conclusions: Enteroparasitosis in Peru are not related to HDI. However, the levels of infestation by enteroparasites varied between the different communities, and they were related to the bioecological characteristics of parasites.

Liposarcoma of the spermatic cord presenting as an inguinal hernia.

INTRODUCTION: Dedifferentiated liposarcoma is a rare, highly malignant, rapidly recurring tumor. When found in the spermatic cord, this tumor may deceptively present as an inguinal hernia, and due to its rarity, may not be readily identified. PRESENTATION OF CASE: We report a case of a 46-year old man with dedifferentiated liposarcoma presenting as a slow-growing right inguinal bulge. His surgical management included ipsilateral orchiectomy and excision with wide margins. He received adjuvant focused radiation therapy. CONCLUSION: Liposarcoma of the Spermatic Cord is a rare and highly malignant tumor that rapidly recurs. Therefore, a high degree of suspicion, regular surveillance and imaging are justified.

High strength films from oriented, hydrogen-bonded "graphamid" 2D polymer molecular ensembles.

The linear polymer poly(p-phenylene terephthalamide), better known by its tradename Kevlar, is an icon of modern materials science due to its remarkable strength, stiffness, and environmental resistance. Here, we propose a new two-dimensional (2D) polymer, "graphamid", that closely resembles Kevlar in chemical structure, but is mechanically advantaged by virtue of its 2D structure. Using atomistic calculations, we show that graphamid comprises covalently-bonded sheets bridged by a high population of strong intermolecular hydrogen bonds. Molecular and micromechanical calculations predict that these strong intermolecular interactions allow stiff, high strength (6-8 GPa), and tough films from ensembles of finite graphamid molecules. In contrast, traditional 2D materials like graphene have weak intermolecular interactions, leading to ensembles of low strength (0.1-0.5 GPa) and brittle fracture behavior. These results suggest that hydrogen-bonded 2D polymers like graphamid would be transformative in enabling scalable, lightweight, high performance polymer films of unprecedented mechanical performance.

Layered and scrolled nanocomposites with aligned semi-infinite graphene inclusions at the platelet limit.

Two-dimensional (2D) materials can uniquely span the physical dimensions of a surrounding composite matrix in the limit of maximum reinforcement. However, the alignment and assembly of continuous 2D components at high volume fraction remain challenging. We use a stacking and folding method to generate aligned graphene/polycarbonate composites with as many as 320 parallel layers spanning 0.032 to 0.11 millimeters in thickness that significantly increases the effective elastic modulus and strength at exceptionally low volume fractions of only 0.082%. An analogous transverse shear scrolling method generates Archimedean spiral fibers that demonstrate exotic, telescoping elongation at break of 110%, or 30 times greater than Kevlar. Both composites retain anisotropic electrical conduction along the graphene planar axis and transparency. These composites promise substantial mechanical reinforcement, electrical, and optical properties at highly reduced volume fraction.

Enhanced Graphene Mechanical Properties through Ultrasmooth Copper Growth Substrates.

The combination of extraordinary strength and stiffness in conjunction with exceptional electronic and thermal properties in lightweight two-dimensional materials has propelled graphene research toward a wide array of applications including flexible electronics and functional structural components. Tailoring graphene's properties toward a selected application requires precise control of the atomic layer growth process, transfer, and postprocessing procedures. To date, the mechanical properties of graphene are largely controlled through postprocess defect engineering techniques. In this work, we demonstrate the role of varied catalytic surface morphologies on the tailorability of subsequent graphene film quality and breaking strength, providing a mechanism to tailor the physical, electrical, and mechanical properties at the growth stage. A new surface planarization methodology that results in over a 99% reduction in Cu surface roughness allows for smoothness parameters beyond that reported to date in literature and clearly demonstrates the role of Cu smoothness toward a decrease in the formation of bilayer graphene defects, altered domain sizes, monolayer graphene sheet resistance values down to 120 Ω/□ and a 78% improvement in breaking strength. The combined electrical and mechanical enhancements achieved through this methodology allows for the direct growth of application quality flexible transparent conductive films with monolayer graphene.

Eye trematode infection in small passerines in Peru caused by Philophthalmus lucipetus, an agent with a zoonotic potential spread by an invasive freshwater snail.

Until now, four species of eye trematodes have been found in South America. Of them, Philophthalmus lucipetus (synonymized with Philophthalmus gralli) displays a broad host spectrum, with at least 30 bird species (prevalently large water birds), five mammal species and humans serving as definitive hosts, and with snails Fagotia (Microcolpia) acicularis, Amphimelania holandri, Melanopsis praemorsa and Melanoides tuberculata serving as intermediate hosts. When examining a total of 50 birds of ten species in the wetland of Pantanos de Villa, Lima, Peru in July 2011, eye trematodes were identified visually in the edematous conjunctival sac of 11 (48%) out of 23 resident many-colored rush tyrants Tachuris rubrigastra. Based on morphometric characteristics, the trematodes were identified as P. lucipetus. ITS2 and CO1 gene of the examined specimens combined showed a 99% similarity to an Iranian isolate of Philophthalmus sp. from the intermediate host Melanoides tuberculata, an invasive freshwater snail, suggesting that these two isolates represent the same species with a wide geographical range. Moreover, the prevalence of infection with the philophthalmid cercariae was 31% in 744 Melanoides tuberculata examined in Pantanos de Villa in 2010. It is evident that P. lucipetus occurs throughout the world as well as locally, including Eurasia and South America. Here we report this trematode for the first time in Peru, and we were the first to sequence any of the South American eye trematodes. Low host specificity of P. lucipetus and the invasive character of Melanoides tuberculata as a competent intermediate host suggest that eye trematodosis caused by P. lucipetus may emerge frequently in various parts of the world, especially in the tropics. Increase of the zoonotic potential of the P. lucipetus associated with this invasive snail spreading across the world is predictable and should be of interest for further research.

Controlling surface energy and wetability with Diels-Alder chemistry.

Reversible Diels-Alder chemistry was utilized to manipulate the surface energy of glass substrates. Hydrophobic dieneophiles were prepared and attached to glass slides and capillaries to yield a nonwetting surface. Thermal treatment of the surfaces cleaved the Diels-Alder linkage, and resulted in the fabrication of a hydrophilic surface. Preliminary analysis utilized contact angle (CA) measurements to monitor the change in surface energy, and observed a hydrophilic state (CA - 70 +/- 3 degrees) before attachment of the dieneophile to a hydrophobic state (CA - 101 +/- 9 degrees) followed by regeneration of the hydrophilic state (CA - 70 +/- 6 degrees) upon cleavage of the Diels-Alder linkage. The treatments were then applied to glass capillaries, with effective treatment confirmed by fluid column measurements. Patterned treatments were also demonstrated to provide effective flow gating. Finally, attempts to create self-pressurizing capillaries were unsuccessful due to pronounced contact angle hysteresis for the hydrophobic surface treatment.

Effect of particle hardness on the penetration behavior of fabrics intercalated with dry particles and concentrated particle-fluid suspensions.

The penetration behavior of Kevlar fabric intercalated with dry particles and shear thickening fluids (STF), highly concentrated fluid-particle suspensions, is presented. In particular, the role of particle hardness is explored by comparing fabric treatments containing SiO(2) particles, which are significantly harder than Kevlar, to treatments containing softer poly(methyl methacrylate) (PMMA) particles. The fabric testing includes yarn pull-out, quasi-static spike puncture, and ballistic penetration resistance, performed on single fabric layers. It was found that both dry particle and STF treatments resulted in improvements in fabric properties relative to neat or poly(ethylene glycol) (PEG) treated fabrics. On comparison of treatments with different particle hardness, the SiO(2) materials performed better in all tests than comparable PMMA materials, although the SiO(2) treatments caused yarn failure in pull-out testing, reducing the total pull-out energy. In addition, resistance to yarn pull-out was found to be substantially higher for STF-treated fabrics than for dry particle treated fabrics. However, both dry particle addition and STF treatments exhibited comparable enhancements in puncture and ballistic resistance. These observations suggest that viscous stress transfer, friction, and physical entrainment of hard particles into filaments contribute to the demonstrated improvements in the properties of protective fabrics treated with shear thickening fluids.

Slow drag in polydisperse granular mixtures under high pressure.

The behavior of polydisperse granular materials, composed of mixtures of particles of different sizes, is studied under conditions of high pressure and confinement. Two types of experiments are performed. In the first type, granular mixtures are compressed, with the resulting force-displacement curve used to calculate density and volume modulus. In the second set of experiments, the drag force is measured by pulling a cylinder, horizontally, through a compressed granular mixture. The density, volume modulus, and drag forces for the mixtures are quantified in terms of the mixture composition. The results show that the behavior of these mixtures depends strongly on the mass fractions of the different sized particles, with density, volume modulus, and drag force all reaching values significantly higher than observed in the monodisperse granular materials. Furthermore, the trends for density and drag force show strong correlation, suggesting that drag resistance of confined granular media could be directly related to packing effects. These results should prove useful in understanding the physics of drag in granular materials under high pressure, such as ballistic penetration of soils or ceramic armors.

Slow drag in granular materials under high pressure.

The resistance offered by a cylindrical rod to creeping cross flow of granular materials under pressure is investigated. The experimental system consists of a confined bed of granular particles, which are compacted under high pressure to consolidate the granular medium. A cylindrical rod is pulled at a constant and slow rate through the granular medium, and the measured pulling resistance is characterized as a drag force. The influence of various parameters such as the velocity of the cylindrical rod, the rod diameter and length, the granular particle size, and the compaction pressure on the required drag force is investigated experimentally. Nondimensional analysis is performed to simplify the relationships between these variables. The results show that the drag force is independent of the drag velocity, is linearly proportional to compaction pressure and rod diameter, and increases with rod length and particle size. Additional compaction experiments show that the effective density of the granular bed increases linearly with pressure, and similar behavior is noted for all particle sizes. These results should prove useful in the development of constitutive equations that can describe the motion of solid objects through compacted granular media under high pressure, such as during ballistic penetration of soils or ceramic armors.

The influence of habitat on the distribution and abundance of metacercariae of Macravestibulum obtusicaudum (Pronocephalidae) in a small Indiana stream.

Snails (Elimia livescens) from a central Indiana stream were examined for encysted metacercariae of Macravestibulum obtusicaudum (Pronocephalide) to determine the distribution and abundance of this parasite on its second intermediate host. Five samples of snails were collected, with 2 samples being restricted to high-flow (riffle) or low-flow (pool) areas of the stream. Snails (n = 386) were measured for shell length; the shell and the inner and outer surfaces of the operculum (in most samples) were examined for metacercariae. Seventy-five percent of snails (overall) had encysted metacercariae (range, 52-97%), primarily on the opercula. A significantly lower proportion of snails from riffles were infected, and these snails had significantly fewer cysts as well. Snails collected from pools showed up to 10 times as many metacercariae than those from riffles, although there was no significant difference in the proportion of snails with intramolluscan infections of M. obtusicaudum. The inner opercular surface appeared to be the preferred site of encystment in both flow regimes. Differences in microhabitats, in terms of both snails in the stream and metacercariae on the snails, clearly must be considered when evaluating the infection patterns of this trematode.