bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical Applications of Circulating Tumour DNA in Pancreatic Adenocarcinoma
Authors: Loft Matthew , Lee Belinda , Tie Jeanne , Gibbs Peter
Published: July 2019

Pancreatic adenocarcinoma remains one of the most aggressive cancers with an ongoing dismal survival rate despite some recent advances in treatment options. This is largely due to the typically late presentation and limited effective therapeutic options in advanced disease. There are numerous circulating biomarkers that have potential clinical application as tumour markers, including circulating tumour DNA (ctDNA), circulating tumour cells (CTCs), cell-free RNA (cfRNA), exosomes and circulating tumour proteins. This review will focus on the development of ctDNA as a non-invasive liquid biopsy, with its high sensitivity and specificity having potential clinical applications in pancreatic cancer. These include a role in screening, prognostication via the detection of minimal residual disease, early detection of recurrence, and for patients with advanced disease; tumour genotyping and monitoring treatment response. Prospective randomised adjuvant clinical trials are currently underway, exploring the impact of ctDNA-guided adjuvant therapy decisions. In this review, we provide perspectives on the current literature and considerations of future directions.
Impact of Process Parameters on the Quality of Deep Holes Drilled in Inconel 718 Using EDD
Authors: Machno Magdalena
Published: July 2019

Advanced engineering materials (e.g., nickel or titanium alloy) are being increasingly applied to produce parts of gas turbines in the aerospace industry. To improve the durability of these parts, many holes, with a length-to-diameter aspect ratio greater than 20:1, are created in their structure. The quality of the holes significantly affects the cooling process of the elements. However, it is challenging to machine materials by conventional methods. When machining a hole with a high aspect ratio, the major problem is effective flushing of the machining area, which can improve the hole’s surface integrity and dimensional accuracy. Consequently, the electro-discharge drilling (EDD) process is good alternative for this application. This paper presents the results of an analysis of the EDD of Inconel 718 alloy. An experiment was conducted to evaluate the impact of process parameters (pulse time, current amplitude, and discharge voltage) on the process’s performance (linear tool wear, taper angle, drilling speed, the hole’s aspect ratio, and surface roughness (Ra and Rz)). The results show that EDD provides us with the possibility to drill holes with an aspect ratio greater than 10:1. The results also demonstrate that holes with an aspect ratio greater than 10:1 and a small taper angle value have a significantly decreased quality of internal surface, especially at the bottom of the hole. This indicates that an insufficient amount of debris is removed from the bottom of the hole.
Phosphorene Is the New Graphene in Biomedical Applications
Authors: Tatullo Marco , Genovese Fabio , Aiello Elisabetta , Amantea Massimiliano , Makeeva Irina , Zavan Barbara , Rengo Sandro , Fortunato Leonzio
Published: July 2019

Nowadays, the research of smart materials is focusing on the allotropics, which have specific characteristics that are useful in several areas, including biomedical applications. In recent years, graphene has revealed interesting antibacterial and physical peculiarities, but it has also shown limitations. Black phosphorus has structural and biochemical properties that make it ideal for biomedical applications: 2D sheets of black phosphorus are called Black Phosphorene (BP), and it could replace graphene in the coming years. BP, similar to other 2D materials, can be used for colorimetric and fluorescent detectors, as well as for biosensing devices. BP also shows high in vivo biodegradability, producing non-toxic agents in the body. This characteristic is promising for pharmacological applications, as well as for scaffold and prosthetic coatings. BP shows low cytotoxicity, thus avoiding the induction of local inflammation or toxicity. As such, BP is a good candidate for different applications in the biomedical sector. Properties such as biocompatibility, biodegradability, and biosafety are essential for use in medicine. In this review, we have exploited all such aspects, also comparing BP with other similar materials, such as the well-known graphene.
Molecular Dynamics Simulations of Atomic Diffusion during the Al–Cu Ultrasonic Welding Process
Authors: Yang Jingwei , Zhang Jie , Qiao Jian
Published: July 2019

Ultrasonic welding (UW) is an important joining technique in the electrical industry. Molecular dynamic simulation has been shown to possess several advantages for revealing the evolution of the atomic-scale structure and the interpretation of diffusion mechanisms at the microscopic level. However, voids associated with the understanding of microstructure evolution in the weld zone and dynamic processes that occur during ultrasonically welded materials still exist, and no UW studies at the atomic scale have so far been reported. In this study, molecular dynamic simulations of UW between Al and Cu were performed to investigate the diffusion behaviors of Al and Cu atoms. The results confirmed the occurrence of asymmetrical diffusion at the Al/Cu interface during UW. Meanwhile, recovery was noticed in the disordered Al blocks at low temperature. The thickness of the diffusion layer increased with the welding time. For relatively long welding times (1 ns), the concentrations of Al and Cu revealed the appearance of phase transitions. In addition, the diffusion during UW was identified as a dynamic and unsteady process. The diffusion coefficient was much larger than that underwent during the steady diffusion process despite the low interfacial temperature (below 375 K), which was mainly attributed to shear plastic deformation at the interface.
Low Temperature Synthesis of Aegirine NaFeSi2O6: Spectroscopy (57Fe Mössbauer, Raman) and Size/Strain Analysis from X-ray Powder Diffraction
Authors: Redhammer Günther J. , Weber Julian , Tippelt Gerold , Zickler Gregor A. , Reyer Andreas
Published: July 2019

Using a low temperature synthesis protocol, it was possible to obtain phase-pure synthetic aegirine (NaFeSi2O6) at temperatures as low as 130 °C, albeit only with rather long synthesis times of ~200 h; at 155 °C, a nano-crystallite shaped phase-pure material is formed after 24 h. These are, to the best of our knowledge, the lowest temperatures reported so far for phase-pure aegirine synthesis. Powder X-ray diffraction (PXRD) was used to characterize phase purity, structural state and microstructural properties (size and strain) of the as-synthesized (130–230 °C) and heat treated (300–900 °C) samples, via Rietveld analysis of powder patterns. Melting was observed at 999 °C. With increasing synthesis temperature, crystallite size linearly increased from 10 nm to 30 nm at 230 °C, while unit cell parameters decreased. The microstrain was very small. Additional heat treatment of as synthesized samples showed that the crystallite size remained rather unaffected up to 700 °C. The lattice parameters, however, already changed at low temperatures and successively became smaller, indicating increasing ordering towards more regular arrangements of building units. This was confirmed by 57Fe Mössbauer spectroscopy, where a distinct decrease of the quadrupole splitting with increasing synthesis temperature was found. Finally, Raman spectroscopy showed that some weakly-developed pre-ordering effects were present in the samples, which appeared to be amorphous in PXRD, while well-resolved spectra appeared as soon as the long-range ordered crystalline state could be found with X-ray diffraction.
Identification of Auxin Metabolites in Brassicaceae by Ultra-Performance Liquid Chromatography Coupled with High-Resolution Mass Spectrometry
Authors: Revelou Panagiota-Kyriaki , Kokotou Maroula G. , Constantinou-Kokotou Violetta
Published: July 2019

Auxins are signaling molecules involved in multiple stages of plant growth and development. The levels of the most important auxin, indole-3-acetic acid (IAA), are regulated by the formation of amide and ester conjugates with amino acids and sugars. In this work, IAA and IAA amide conjugates with amino acids bearing a free carboxylic group or a methyl ester group, along with some selected IAA metabolites, were studied in positive and negative electrospray ionization (ESI) modes, utilizing high-resolution mass spectrometry (HRMS) as a tool for their structural analysis. HRMS/MS spectra revealed the fragmentation patterns that enable us to identify IAA metabolites in plant extracts from eight vegetables of the Brassicaceae family using a fast and reliable ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QToF-MS) method. The accurate m/z (mass to charge) ratio and abundance of the molecular and fragment ions of the studied compounds in plant extracts matched those obtained from commercially available or synthesized compounds and confirmed the presence of IAA metabolites.
Dissipation Kinetics and the Pre-Harvest Residue Limits of Acetamiprid and Chlorantraniliprole in Kimchi Cabbage Using Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry
Authors: Lee Jonghwa , Kim Byung Joon , Kim Eunhye , Kim Jeong-Han
Published: July 2019

The dissipation behaviors of acetamiprid and chlorantraniliprole in kimchi cabbages were studied under open-field conditions. A simple and rapid analytical method was developed using ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The multiple reaction monitoring (MRM) conditions of two pesticides were optimized to quantify and identify the pesticide residues. Sample preparation was performed by the QuEChERS (quick, easy, cheap, effective, rugged, and safe) method. Average recovery rates at the different spiked levels (0.05 and 0.25 mg/kg) were in the range of 103.6–113.9% (acetamiprid) and 80.8–91.2% (chlorantraniliprole), and the relative standard deviations were ≤4.3% for all. The dissipation kinetics were assessed using first-order equations after spraying acetamiprid and chlorantraniliprole individually on kimchi cabbages. The biological half-lives in field 1 and 2 were 5.2 and 6.3 days (acetamiprid) and 10.0 and 15.2 days (chlorantraniliprole), respectively. Based on the dissipation equations, the pre-harvest residue limits (PHRLs) corresponding to each day before harvest were suggested as the guidelines to meet the MRL on harvest day. It was also predicted that the terminal residues observed after multiple sprayings (three and seven days) would be below the MRL when harvested, in compliance with the established pre-harvest intervals.
Production of Biosurfactant Produced from Used Cooking Oil by Bacillus sp. HIP3 for Heavy Metals Removal
Authors: Md Badrul Hisham Nurul Hanisah , Ibrahim Mohamad Faizal , Ramli Norhayati , Abd-Aziz Suraini
Published: July 2019

Heavy metals from industrial effluents and sewage contribute to serious water pollution in most developing countries. The constant penetration and contamination of heavy metals into natural water sources may substantially raise the chances of human exposure to these metals through ingestion, inhalation, or skin contact, which could lead to liver damage, cancer, and other severe conditions in the long term. Biosurfactant as an efficient biological surface-active agent may provide an alternative solution for the removal of heavy metals from industrial wastes. Biosurfactants exhibit the properties of reducing surface and interfacial tension, stabilizing emulsions, promoting foaming, high selectivity, and specific activity at extreme temperatures, pH, and salinity, and the ability to be synthesized from renewable resources. This study aimed to produce biosurfactant from renewable feedstock, which is used cooking oil (UCO), by a local isolate, namely Bacillus sp. HIP3 for heavy metals removal. Bacillus sp. HIP3 is a Gram-positive isolate that gave the highest oil displacement area with the lowest surface tension, of 38 mN/m, after 7 days of culturing in mineral salt medium and 2% (v/v) UCO at a temperature of 30 °C and under agitation at 200 rpm. An extraction method, using chloroform:methanol (2:1) as the solvents, gave the highest biosurfactant yield, which was 9.5 g/L. High performance liquid chromatography (HPLC) analysis confirmed that the biosurfactant produced by Bacillus sp. HIP3 consists of a lipopeptide similar to standard surfactin. The biosurfactant was capable of removing 13.57%, 12.71%, 2.91%, 1.68%, and 0.7% of copper, lead, zinc, chromium, and cadmium, respectively, from artificially contaminated water, highlighting its potential for bioremediation.
Ampelopsin E Reduces the Invasiveness of the Triple Negative Breast Cancer Cell Line, MDA-MB-231
Authors: Tieng Francis Yew Fu , Latifah Saiful Yazan , Md Hashim Nur Fariesha , Khaza’ai Huzwah , Ahmat Norizan , Gopalsamy Banulata , Wibowo Agustono
Published: July 2019

Breast cancer is the most common and the second leading cause of cancer-related deaths in women. It has two distinctive hallmarks: rapid abnormal growth and the ability to invade and metastasize. During metastasis, cancer cells are thought to form actin-rich protrusions, called invadopodia, which degrade the extracellular matrix. Current breast cancer treatments, particularly chemotherapy, comes with adverse effects like immunosuppression, resistance development and secondary tumour formation. Hence, naturally-occurring molecules claimed to be less toxic are being studied as new drug candidates. Ampelopsin E, a natural oligostilbene extracted from Dryobalanops species, has exhibited various pharmacological properties, including anticancer and anti-inflammatory activities. However, there is yet no scientific evidence of the effects of ampelopsin E towards metastasis. Scratch assay, transwell migration and invasion assays, invadopodia and gelatin degradation assays, and ELISA were used to determine the effects of ampelopsin E towards the invasiveness of MDA-MB-231 cells. Strikingly in this study, ampelopsin E was able to halt migration, transmigration and invasion in MDA-MB-231 cells by reducing formation of invadopodia and its degradation capability through significant reduction (p < 0.05) in expression levels of PDGF, MMP2, MMP9 and MMP14. In conclusion, ampelopsin E reduced the invasiveness of MDA-MB-231 cells and was proven to be a potential alternative in treating TNBC.
Cyclization of Single-Chain Fv Antibodies Markedly Suppressed Their Characteristic Aggregation Mediated by Inter-Chain VH-VL Interactions
Authors: Yamauchi Soichiro , Kobashigawa Yoshihiro , Fukuda Natsuki , Teramoto Manaka , Toyota Yuya , Liu Chenjiang , Ikeguchi Yuka , Sato Takashi , Sato Yuko , Kimura Hiroshi , Masuda Takeshi , Ohtsuki Sumio , Noi Kentaro , Ogura Teru , Morioka Hiroshi
Published: July 2019

Single-chain Fv (scFv) antibodies are recombinant proteins in which the variable regions of the heavy chain (VH) and light chain (VL) are connected by a short flexible polypeptide linker. ScFvs have the advantages of easy genetic manipulation and low-cost production using Escherichia coli compared with monoclonal antibodies, and are thus expected to be utilized as next-generation medical antibodies. However, the practical use of scFvs has been limited due to low homogeneity caused by their aggregation propensity mediated by inter-chain VH-VL interactions. Because the interactions between the VH and VL domains of antibodies are generally weak, individual scFvs are assumed to be in equilibrium between a closed state and an open state, in which the VH and VL domains are assembled and disassembled, respectively. This dynamic feature of scFvs triggers the formation of dimer, trimer, and larger aggregates caused by the inter-chain VH-VL interactions. To overcome this problem, the N-terminus and C-terminus were herein connected by sortase A-mediated ligation to produce a cyclic scFv. Open-closed dynamics and aggregation were markedly suppressed in the cyclic scFv, as judged from dynamic light scattering and high-speed atomic force microscopy analyses. Surface plasmon resonance and differential scanning fluorometry analysis revealed that neither the affinity for antigen nor the thermal stability was disrupted by the scFv cyclization. Generality was confirmed by applying the present method to several scFv proteins. Based on these results, cyclic scFvs are expected to be widely utilized in industrial and therapeutic applications.
Terpene Derivatives as a Potential Agent against Antimicrobial Resistance (AMR) Pathogens
Authors: Mahizan Nik Amirah , Yang Shun-Kai , Moo Chew-Li , Song Adelene Ai-Lian , Chong Chou-Min , Chong Chun-Wie , Abushelaibi Aisha , Lim Swee-Hua Erin , Lai Kok-Song
Published: July 2019

The evolution of antimicrobial resistance (AMR) in pathogens has prompted extensive research to find alternative therapeutics. Plants rich with natural secondary metabolites are one of the go-to reservoirs for discovery of potential resources to alleviate this problem. Terpenes and their derivatives comprising of hydrocarbons, are usually found in essential oils (EOs). They have been reported to have potent antimicrobial activity, exhibiting bacteriostatic and bactericidal effects against tested pathogens. This brief review discusses the activity of terpenes and derivatives against pathogenic bacteria, describing the potential of the activity against AMR followed by the possible mechanism exerted by each terpene class. Finally, ongoing research and possible improvisation to the usage of terpenes and terpenoids in therapeutic practice against AMR are discussed.
GFET Asymmetric Transfer Response Analysis through Access Region Resistances
Authors: Toral-Lopez Alejandro , Marin Enrique G. , Pasadas Francisco , Gonzalez-Medina Jose Maria , Ruiz Francisco G. , Jiménez David , Godoy Andres
Published: July 2019

Graphene-based devices are planned to augment the functionality of Si and III-V based technology in radio-frequency (RF) electronics. The expectations in designing graphene field-effect transistors (GFETs) with enhanced RF performance have attracted significant experimental efforts, mainly concentrated on achieving high mobility samples. However, little attention has been paid, so far, to the role of the access regions in these devices. Here, we analyse in detail, via numerical simulations, how the GFET transfer response is severely impacted by these regions, showing that they play a significant role in the asymmetric saturated behaviour commonly observed in GFETs. We also investigate how the modulation of the access region conductivity (i.e., by the influence of a back gate) and the presence of imperfections in the graphene layer (e.g., charge puddles) affects the transfer response. The analysis is extended to assess the application of GFETs for RF applications, by evaluating their cut-off frequency.
A Multilayer Emitter Close to Ideal Solar Reflectance for Efficient Daytime Radiative Cooling
Authors: Zhu Yeqing , Wang Dong , Fang Cheng , He Ping , Ye Yong-Hong
Published: July 2019

A passive radiative cooling method has a significant influence on thermal management applications because it can cool without any energy input. This work both experimentally and theoretically demonstrates a multilayer thin film structure with high solar reflectance, which can be applied to passive daytime radiative cooling. The combination of physical vapor deposition and spin-coating prepared the samples, which were also characterized experimentally by spectrometers. On-site measured results show that the emitter can effectively achieve daytime radiative cooling, and the cooling performance can be further improved with the increase of the ambient air temperature. When the emitter is exposed to direct solar radiation (AM1.5) of about 880 W/m2 on a rooftop under dry air conditions, it can achieve an average temperature reduction of about 12.6 °C from the ambient air temperature with nonradiative heat transfer (11 a.m.–1 p.m.). Theoretical simulations reveal that the emitter can still have a certain cooling performance in the presence of significant nonradiative heat exchange and nonideal atmospheric conditions. The influence of ambient air temperature on the cooling performance of the emitter is also theoretically analyzed.
Water Resistant Self-Extinguishing Low Frequency Soundproofing Polyvinylpyrrolidone Based Electrospun Blankets
Authors: Passaro Jessica , Russo Paolo , Bifulco Aurelio , De Martino Maria Teresa , Granata Veronica , Vitolo Bonaventura , Iannace Gino , Vecchione Antonio , Marulo Francesco , Branda Francesco
Published: July 2019

This paper shows that an eco-friendly electrospinning process allows us to produce water resistant sound absorbers with reduced thickness and excellent sound-absorption properties in the low and medium frequency range (250–1600 Hz) for which which human sensitivity is high and traditional materials struggle to match, that also pass the fire tests which are mandatory in many engineering areas. The structure and composition were studied through Scanning Electron Microscopy (SEM), Fourier Transform InfraRed (FTIR) Spectroscopy and ThermoGravimetric Analysis (TGA). The density, porosity and flow resistivity were measured. Preliminary investigation of the thermal conductivity through Differential Scanning Calorimetry (DSC) shows that they have perspectives also for thermal insulation. The experimental results indicate that the achievements are to be ascribed to the chemical nature of Polyvinylpyrrolidone (PVP). PVP is, in fact, a polymeric lactam with a side polar group that may be easily released by a thermooxidative process. The side polar groups allow for using ethanol for electrospinning than relying on a good dispersion of silica gel particles. The silica particles dimensionally stabilize the mats upon thermal treatments and confer water resistance while strongly contributing to the self-extinguishing property of the materials.
Retrieval of Internal Solitary Wave Amplitude in Shallow Water by Tandem Spaceborne SAR
Authors: Jia Tong , Liang Jianjun , Li Xiao-Ming , Fan Kaiguo
Published: July 2019

The accurate estimation of the upper layer thickness in a two-layer ocean is a crucial step in the retrieval of internal solitary wave (ISW) amplitude from synthetic aperture radar (SAR) data. In this paper, we present a method to derive the upper layer thickness and the consequent ISW amplitude by combining two consecutive SAR images with the extended Korteweg-de Vries (eKdV) equation. An ISW case observed twice by the Chinese C-band SAR GaoFen-3 (GF-3) and the German X-band SAR TerraSAR-X (TS-X) with a temporal interval of approximately 11 min in shallow water to the southeast of Hainan Island in the northwestern South China Sea was used to demonstrate the applicability of the method. Using the in situ measurements of temperature and salinity near the observed ISW, the proposed method yielded an ISW amplitude of −4.52 m, in close proximity to −5.66 ± 1.24 m derived by applying the classic Korteweg–de Vries (KdV) equation based on the continuously stratified theory. Moreover, the climatological dataset of the World Ocean Atlas 2013 (WOA13) was also used with the proposed method in the Hainan case, and the results showed that the method can still provide a reasonable estimate of ISW amplitude in shallow water even when in situ oceanic stratification measurements are absent. The application of our method to derive the ISW amplitude from consecutive SAR images seems highly promising with the increasing emergence of tandem satellites in orbits.
Rapid Assessment of a Typhoon Disaster Based on NPP-VIIRS DNB Daily Data: The Case of an Urban Agglomeration along Western Taiwan Straits, China
Authors: Zheng Yuanmao , Shao Guofan , Tang Lina , He Yuanrong , Wang Xiaorong , Wang Yening , Wang Haowei
Published: July 2019

Rapid assessment of natural disasters is essential for disaster analysis and spatially explicit strategic decisions of post-disaster reconstruction but requires timely available data. The recent daily data of the National Polar-Orbiting Partnership Visible Infrared Imaging Radiometer Suite (NPP-VIIRS) day/night band (DNB) provide new opportunities to detect and evaluate natural disasters. Here, we introduce an application of NPP-VIIRS DNB daily data for rapidly assessing the damage of a severe typhoon that struck the urban agglomerations along the western Taiwan Straits in China. Our research explored the methods of rapid identification and extraction of the areas based on changes in nighttime light (NTL) after the typhoon disaster by using a statistical radiation-normalization method. We analyzed the correlations of NTL image derivatives with human population, population density, and gross domestic product (GDP). The strong correlations were found between NTL image light density and population density (R2 = 0.83) and between the total nighttime light intensity and GDP (R2 = 0.96) at the prefecture level. In addition, we examined the interrelationships between changes in NTL images and the areas affected by the typhoon and proposed a method to predict the affected population. Finally, the affected area and the affected population in the study area could be rapidly retrieved based on the proposed remote sensing method. The overall accuracy was 83.2% for the detection of the affected population after disaster and the recovery rate of the affected area was 86.9% in the third week after the typhoon. This research demonstrates that the NTL image-based change detection method is simple and effective, and further explains that the NPP-VIIRS DNB daily data are useful for rapidly assessing affected areas and affected populations after typhoon disasters, and for timely quantifying the degree of recovery at a large spatial scale.
Classification of Postprandial Glycemic Status with Application to Insulin Dosing in Type 1 Diabetes—An In Silico Proof-of-Concept
Authors: Cappon Giacomo , Facchinetti Andrea , Sparacino Giovanni , Georgiou Pantelis , Herrero Pau
Published: July 2019

In the daily management of type 1 diabetes (T1D), determining the correct insulin dose to be injected at meal-time is fundamental to achieve optimal glycemic control. Wearable sensors, such as continuous glucose monitoring (CGM) devices, are instrumental to achieve this purpose. In this paper, we show how CGM data, together with commonly recorded inputs (carbohydrate intake and bolus insulin), can be used to develop an algorithm that allows classifying, at meal-time, the post-prandial glycemic status (i.e., blood glucose concentration being too low, too high, or within target range). Such an outcome can then be used to improve the efficacy of insulin therapy by reducing or increasing the corresponding meal bolus dose. A state-of-the-art T1D simulation environment, including intraday variability and a behavioral model, was used to generate a rich in silico dataset corresponding to 100 subjects over a two-month scenario. Then, an extreme gradient-boosted tree (XGB) algorithm was employed to classify the post-prandial glycemic status. Finally, we demonstrate how the XGB algorithm outcome can be exploited to improve glycemic control in T1D through real-time adjustment of the meal insulin bolus. The proposed XGB algorithm obtained good accuracy at classifying post-prandial glycemic status (AUROC = 0.84 [0.78, 0.87]). Consequently, when used to adjust, in real-time, meal insulin boluses obtained with a bolus calculator, the proposed approach improves glycemic control when compared to the baseline bolus calculator. In particular, percentage time in target [70, 180] mg/dL was improved from 61.98 (±13.89) to 67.00 (±11.54; p < 0.01) without increasing hypoglycemia.
Vulnerability of a Northeast Mediterranean Island to Soil Loss. Can Grazing Management Mitigate Erosion?
Authors: Panagopoulos Yiannis , Dimitriou Elias , Skoulikidis Nikolaos
Published: July 2019

Grazing management practices can be erosion abatement actions for lowering soil loss and the subsequent sediment pollution of surface water bodies. Process-based Geographic Information Systems models provide the opportunity to identify critical areas and hence better target such actions across the landscape. This study implemented the SWAT (Soil Water Assessment Tool) hydrologic and catchment management model to estimate the soil loss vulnerability of the nearly pristine but highly erodible Greek island of Samothraki in the North Aegean Sea, with a typical Mediterranean climate and steep topography. Model parameterization and evaluation were carried out by taking advantage of previous modeling experience on areas with data limitations. Inter-annual and intra-annual soil loss variability and the most critical areas (subbasins) of soil loss to waters were adequately identified and grazing management scenarios, including livestock reductions by 50% and 100%, grazing period reduction, and a combination of them, were formulated and applied to investigate the degree to which soil loss could be reduced. The annual reduction results varied between scenarios in the range of 10% to 25% for the entire island, and in wider ranges for its individual subbasins, showing a high potential for reducing the vulnerability of the most pressured ones. However, due to the high importance of the natural factors of rainfall and land slopes, the erosion vulnerability of the island overall could be significantly altered only if grazing management was integrated within a vegetation regeneration plan that included reforestation.
Si tú escucharas lo que yo veo: la educación básica para sordos usuarios de la LSM
Authors: Cruz-Aldrete Miroslava , Villa Rodríguez Miguel Ángel
Published: July 2019

En México, hoy en día, el estado garantiza el derecho a cursar la educación básica (inicial, primaria y secundaria) para todos sus ciudadanos. No obstante, no se ha logrado que las comunidades lingüísticas minoritarias, entre ellas la comunidad sorda, gocen totalmente de este derecho. Las razones son variadas, desde la inequidad en el destino de recursos para la implementación de escuelas dignas, la carencia de maestros que sean bilingües (lengua originaria y lengua dominante), y la falta de un espacio de reflexión sobre el desarrollo de un modelo bilingüe bicultural/intercultural. La intención de este trabajo es discutir la urgencia de evaluar la educación de los sordos usuarios de la Lengua de Señas Mexicana bajo la propuesta de un modelo bilingüe, para ello tomamos como ejemplo las experiencias de distintas comunidades educativas de nuestro país, con el fin de esclarecer los retos que deben ser atendidos para asegurar que el sordo goce de la mismas oportunidades educativas como cualquier ciudadano.
Proteínas asociadas al manejo del calcio intracelular en el miocardio como blancos potenciales de modificaciones redox
Authors:   , Román Bárbara Soledad
Published: July 2019

En resumen, nuestros resultados aportan evidencias que amplían el conocimiento sobre los potenciales mecanismos subcelulares que conducen a las arritmias de reperfusión. Pudimos comprobar que el estrés oxidativo contribuye a la alteración del ritmo cardíaco en un modelo de I/R en corazón aislado. Demostramos la presencia de modificaciones redox tanto en CaMKII como en el RyR2 durante la reperfusión postisquémica. Evidenciamos que las oxidaciones reversibles del RyR2 como la S-nitrosilación y la S-glutationilación restringen las arritmias (oxidaciones protectoras), mientras que otras oxidaciones amplifican el efecto arritmogénico de la fosforilación del canal debida a CaMKII. En miocitos aislados, pudimos demostrar que las alteraciones redox del RyR2, junto con su fosforilación por CaMKII, aumentan la actividad del canal, generando un escenario propicio para las arritmias de reperfusión. Los resultados de este trabajo de Tesis permitirían suponer que las estrategias farmacológicas y no farmacológicas que intentan reducir el estrés oxidativo causado por la I/R, podrían ser una terapéutica apropiada en las arritmias de reperfusión. Sin embargo, diversos estudios clínicos han revelado que la terapia antioxidante en este contexto no ha dado los resultados esperados (Lonborg 2015; Sinning y col. 2017; Farías y col. 2017). La limitación de estos tratamientos radicaría entre otras razones, en la falta de identificación de las fuentes de producción de ROS/RNS y/o en la incapacidad de dirigir los antioxidantes hacia los compartimentos subcelulares adecuados. Esperamos que este trabajo experimental contribuya a aclarar las bases moleculares del fenómeno arrítmico permitiendo una mejor implementación de la terapia antioxidante con el fin de resolver esta complicación frecuente de la reperfusión coronaria, la cual, por su severidad, pone en riesgo la vida de los pacientes con infarto de miocardio, enfermedad con una alta prevalencia en nuestro país y en el mundo.
Desarrollo de una mezcla microbiana para la inclusión como probiótico en la industria avícola: estudio de su acción sobre hongos contaminantes y micotoxinas
Authors:   , Correa Franco Mariana
Published: July 2019

Se evaluó la potencialidad probiótica de un grupo de microorganismos obtenidos del kefir en pollos parrilleros. El kefir es un producto ancestral y natural con comprobada acción probiótica en humanos. Para este fin se planteó el uso de permeado de suero como sustrato de fermentación de los microorganismos seleccionados. Previo a los ensayos in vivo se realizaron estudios in vitro de los microorganismos seleccionados y el permeado de suero fermentado con los mismos. Se analizó la capacidad antifúngica, tanto de los microorganismos como de permeado de suero (PS) fermentado por éstos, contra hongos aislados en distintas etapas la cría de pollos parrilleros. Se probó la capacidad de los microorganismos estudiados en la protección de una línea celular, frente a la acción tóxica de la aflatoxina B1. Para finalizar los ensayos in vitro se comprobó la capacidad de los microorganismos de capturar AFB1 en diferentes concentraciones. Una vez probados todos los desafíos in vitro, tanto el PS fermentado como las cepas se suministraron a pollos parrilleros, comprobando que tienen efectos benéficos y son cepas inocuas para las aves.
La reforma (conservadora) de la enseñanza secundaria en el Uruguay (1933-1938)
Authors:   , Romano Antonio
Published: July 2019

La investigación que aborda las transformaciones que se producen en la enseñanza secundaria en la década del 30, después de un proceso de discusión que comenzó a principios de los 20 pero que logró su concreción década y media después. Durante ese periodo ocurren algunos eventos importantes: la irrupción de un régimen de facto, la consolidación de la Asociación de Profesores de Enseñanza Secundaria (APES) como un actor colectivo organizado, el fracaso de la reforma del plan de estudios de 1932, la aparición de la Federación de Estudiantes del Uruguay (FEUU) y la sanción de la ley que separa a la Enseñanza Secundaria de la Universidad de la República. Algunas de las preguntas que busca responderse esta tesis son: ¿Por qué razón tardó tanto tiempo en concretarse una reforma que venía anunciándose durante más de una década? ¿Por qué el proyecto de ley que consagra la autonomía de Enseñanza Secundaria se produjo en el contexto de un régimen autoritario? La hipótesis propuesta es que la reforma educativa que separa a enseñanza secundaria de la Universidad se concreta porque el Poder Ejecutivo encuentra apoyo en la APES, logrando en un mismo movimiento la identificación de la defensa de la autonomía con la sanción de la ley 9.523 que separa a la enseñanza secundaria de la Universidad. Se demostrará esta hipótesis a partir de la exploración en fuentes originales: archivos institucionales, prensa, congresos entre otros.
Horizontes disciplinares del Diseño Industrial
Authors:   , Sierra María Sol
Published: July 2019

Este trabajo de tesis se centra en analizar la función del Diseño Industrial en la sociedad actual. Con este objetivo y tomando como grupo de estudio a los profesionales de la Universidad Nacional de La Plata (UNLP, La Plata, Argentina), se realizó un análisis organizado en tres ejes: la formación académica de Diseño Industrial en la Facultad de Bellas Artes (FBA-UNLP); la inserción laboral de los diseñadores industriales; y el ejercicio laboral de los diseñadores industriales. Considerando las investigaciones precedentes, se definieron las muestras y se realizaron entrevistas a diecisiete diseñadores industriales: tres informantes clave y catorce casos de estudio. La información recabada -combinando fuentes primarias y secundarias- fue procesada enmarcada siempre en una metodología cualitativa y estudiándose en profundidad los tres ejes mencionados con el fin de contrastar las hipótesis, ofreciendo un interesante y complejo corpus teórico sin precedentes para este objeto de estudio.
Modulación del sistema de defensas antiherbívoro en Solanum lycopersicum por señales lumínicas de competencia percibidas por el fitocromo
Authors:   , Cortés Leandro Emanuel
Published: July 2019

La competencia y la herbivoría son dos fuerzas selectivas en la evolución de las plantas terrestres. Éstas deben crecer lo suficientemente rápido como para ser competitivas con sus vecinos y, al mismo tiempo, asignar recursos a las defensas para poder sobrevivir a los organismos consumidores. Estudios recientes mostraron que las señales lumínicas asociadas a la competencia, p. ej. una baja relación rojo:rojo lejano (R:RL) produce la represión del sistema de defensas, tornando a las plantas más susceptibles al ataque de insectos herbívoros y microorganismos patógenos. Bajo condiciones de competencia por luz, se produce la inactivación del fitocromo B (phyB) lo cual en plantas intolerantes a la sombra promueve el crecimiento y regula negativamente los sistemas de defensa antiherbívoro. Poco se sabe sobre los efectos que tiene el phyB en la emisión de compuestos orgánicos volátiles (VOCs) involucrados en las defensas indirectas. En esta tesis se investigó el efecto de phyB en las defensas directas e indirectas de tomate (Solanum lycopersicum). Para esto se utilizaron dos aproximaciones diferentes para inactivar el phyB: suplementación con luz rojo lejana (RL), y genotipos mutantes de los dos genes PHYB presentes en el genoma de tomate. La inactivación del phyB produjo una disminución en los niveles de defensas constitutivas como así también una atenuación de las defensas directas inducibles por MeJA. Adicionalmente, se observó que la inactivación de phyB tuvo efectos en los blends de VOCs emitidos por las plantas inducidas con MeJA. En ensayos de elección en olfatómetro con plantas inducidas con MeJA observamos que la chinche Macrolophus pygmaeus tuvo mayor preferencia por los blends de VOCs emitidos por plantas con phyB inactivos que por los blends de las wild-type. Estos resultados sugieren que la inactivación del phyB además de reprimir las defensas directas tiene consecuencias sobre las interacciones tritróficas mediadas por VOCs presumiblemente atrayendo a los predadores a plantas con defensas atenuadas donde existe mayor chance de encontrar a su presa. Es tentador pensar que las plantas bajo un stress de competencia por luz puedan hacer un switch entre sus defensas directas a indirectas y así atraer a enemigos naturales.
Weighing In
Authors: Lasswell Terri A. , Pace Nicholas J. , Reed Gregory A.
Published: July 2019

As the accountability movement has gained momentum, policy makers and educators have strived to strike a difficult balance between the sometimes competing demands at the local, state, and federal levels. Efforts to improve accountability and teacher evaluation have taken an especially unique route in Iowa, where local control and resistance to state mandated curricular standards have been popular topics from the statehouse to the convenience store. This research explores principals’ impressions of Iowa’s state-mandated standards for best-practice teaching (as opposed to state mandated curricular standards). Further, the research examined the extent to which the Iowa Teaching Standards (ITS) and accompanying Iowa Evaluator Approval Training Program (IEATP) have impacted the way teacher evaluations are conducted in the state’s rural schools. Evidence indicates that most principals felt that ITS and the accompanying IEATP made them feel adequately or very well prepared to conduct teacher evaluations. In addition, 65% of respondents reported that IAETP had changed the way teachers are evaluated.
Learning the Language of Home: Using Place-based Writing Practice to Help Rural Students Connect to Their Communities
Authors: Donovan Erin
Published: July 2019

The idea of "place" extends beyond the locations where people live.  Place is a narrative which shapes identity and culture and provides an understanding of experience.  By exploring place and the connections which evolve from place, an intriguing context begins to take a shape that inspires transformational ideas and actions. This article investigates how place-based writing practices affect rural middle school students’ connections with their home community as evidenced through their writing. This study follows the critical pedagogy of place theoretical framework and works to support best practices in rural education research. A qualitative case study design was used to conduct this study in a rural middle school in North Carolina.
Policies and Professional Development: An Oil Boom’s Effect on Rural Schools and Teachers
Authors: Genareo Vincent
Published: July 2019

In 2008, Western North Dakota experienced an extraordinary energy boom, creating waves of new residents seeking employment in the lucrative oil fields. Resultantly, many communities in the area, which were almost exclusively isolated and rural, dramatically changed. The purpose of this qualitative single-case study was to investigate the experiences of school staff in two rural schools within the North Dakota oil boom region. Data were teacher and administrator interviews with 15 participants and classroom observations. The findings indicated that teachers faced three key challenges in their classrooms as a result of the population influx, including: changing educational space, student academic proficiency, and a lack of cultural competence and pedagogical knowledge to effectively educate new, diverse students. Implications for policies and teacher professional development in rural boomtown areas are discussed.
Entre la legalidad y lo clandestino: cementerios de Lima Norte
Authors: Tácunan Bonifacio Santiago
Published: July 2019

En este artículo, la formación de los cementerios comprendidos en Lima Norte será el tema de estudio del autor. En total, los distritos abarcados serán Ancón, Santa Rosa, Puente Piedra, Carabayllo, Comas, Independencia, Los Olivos, San Martín de Porres y Ventanilla. A través de esta propuesta, el lector comprenderá, con una visión más amplia, los cambios y permanencias en torno a la muerte y los usos mortuorios en una de las zonas más pobladas de la capital.
Actividad biológica fumigante del Malathión 4% P. S. en el control de estados inmaduros del gorgojo del maiz Sitophilus zeamais Motschulsky (Coleoptera Curculionidae)
Authors: Rodríguez Cobos Alfredo Carlos
Published: July 2019

En condiciones de laboratorio de 27 + 2º C y 70 + 5% H.R., se procedió a infestar 5 lotes de maíz amarillo duro; cada lote de 1 kg de peso, con aproximadamente 1000 insectos adultos de S. zeamais de 1 a 2 semanas de edad. Después de mantener 2 semanas los adultos sobre los 5 lotes de maíz para su infestación, fueron retirados y descartados con la ayuda de un tamiz. Inmediatamente, se procedió a tratar 4 de los 5 lotes de granos a las dosis de 5, 10, 20 y 40 ppm con el insecticida Malathión 4% P.S., dejándose un lote como testigo sin tratamiento. Los resultados estadísticos del análisis de la variancia (ANOVA), arrojan una alta a regular emergencia de adultos de S. zeamais en los tratamientos a las dosis de 5 y 10 ppm. En cuanto a las dosis mayores de 20 y 40 ppm, se observa una baja emergencia de adultos del insecto, debido, probablemente, al mayor efecto de inhibición del desarrollo de S. zeamais al interior de los granos por la acción fumigante del Malathión 4% P.S.
La vereda de Guimarães Rosa y la verdad de Dostoievski: esbozo para un estudio literario comparado
Authors: D'Angelo Biagio
Published: July 2019

Este testo es la adaptación de una ponencia presentada en el X Congreso Internacional FEIALC (Federación Internacional de Estudios sobre América Latina y el Caribe) en Moscú, del 25 al 29 de junio de 2001, en el simposio "El universo literario de Guimarães Rosa", coordinado por la profesora Léila Parreira Duarte de la Pontificia Universidad de Minas Gerais (Brasil). El autor afirmará que Rosa, de la misma manera que Dostoievski, intenta desesperadamente captar, bajo la forma literaria de la escritura polifónica, lo inexpresable, lo indecible, lo infinito. Guimarães Rosa y Dostoievski han intuido que la búsqueda religiosa no es materia teológica, sino sentimiento pánico del universo, necesidad estructural del hombre.
El aporte del Perú a la vigésima segunda edición del Diccionario de la Real Academia de la Lengua Española
Authors: Portilla Durand Luisa
Published: July 2019

Tras la presentación de la vigésima segunda edición del Diccionario de la RAE, en el 2001, las expresiones peruanas incluidas ascendieron a casi un centenar, respecto de ediciónes anteriores. A raíz de ello, la autora del presente texto ofrecerá una breve muestra de los peruanismos propuestos o enmendados por la Comisión Lexicográfica de la Academia Peruana de la Lengua. Gracias a la rigurosidad con que este aporte es mostrado, el lector podrá apreciar de un modo más preciso y enriquecedor dichos peruanismos.
Libertad religiosa en España y Perú. Entrevista a Mons. Dr. Joaquín Martínez Valls (†)
Authors: Benito Rodríguez José Antonio Antonio
Published: July 2019

Mons. Dr. Joaquín Martínez Valls (†) fue rector de la Universidad Católica Sedes Sapientiae y, luego, designado rector emérito. Durante su permanencia en esta casa de estudios, trabajó fehacientemente por defender y promover una educación cristiana, humanística y científica que velara por el valor de la persona y del bien común. En este diálogo brindó valiosos puntos de vista, a partir de su experiencia, sobre temas cruciales para la educación y la sociedad de hoy. Son de resaltar su valoración de los principios éticos y cristianos en correspondencia con la Doctrina Social de la Iglesia. Al ofrecer esta entrevista, se espera que sirva de homenaje y en agradecimiento a Monseñor Joaquín, quien siempre manifestó un gran afecto y compromiso por el Perú.
Nada en la educación está perdido
Authors: Navarro Linares Janina
Published: July 2019

Ayudante de una farmacia, educador, historiador, director de colegio, instituto y director general de Educación Secundaria en el Minedu; también, autor de libros sobre historia, economía, educación, psicología, entre otros. A través de sus palabras, el profesor César Cortez Mondragón (Chiclayo, 1940) logra expresar una gran pasión y esperanza por la educación peruana. En este diálogo nos compartirá, además, facetas de su vida, experiencia y sabiduría para nuestras generaciones.
Monseñor Severo Aparicio, O. M.
Authors: Benito Rodríguez José Antonio
Published: July 2019

El entrevistador dialogará con Mons. Severo Aparicio, O. M., presidente de la Academia Peruana de Historia Eclesiástica. En las siguientes páginas, Mons. Aparicio hablará sobre su vida, su trayectoria en la investigación histórica, su familia, su vocación religiosa, la Señora de la Merced, la Orden de los Mercedarios, entre otros temas. Asimismo, tendrá palabras de reconocimiento para la comunidad universitaria de la UCSS y su Gran Canciller, Mons. Lino Panizza.
Educación de jóvenes y adultos: una experiencia educativa
Authors: De Souza Ana Lucia
Published: July 2019

En este artículo, se presenta la experiencia del programa de educación de jóvenes y adultos de la Universidad Mackenzie (Brasil). La fundación de esta institución se dio en 1870 con la Escuela Americana, y fue reconocida como universidad en 1952. Si bien la autora reconocerá que el programa posee limitaciones, en la medida de sus posibilidades intenta velar por las necesidades reales de los jóvenes y adultos que participan de este.