The distribution of Pearson residuals in generalized linear models

In general, the distribution of residuals cannot be obtained explicitly. In this paper we give an asymptotic formula for the density of Pearson residuals in continuous generalized linear models corrected to order n⁻¹, where n is the sample size. We define a set of corrected Pearson residuals for these models that, to this order of approximation, have exactly the same distribution of the true Pearson residuals. An application to a real data set and simulation results for a gamma model illustrate the usefulness of our corrected Pearson residuals.     

Mapping vegetation in a late Quaternary landform of the Amazonian wetlands using object-based image analysis and decision tree classification

Fan-shaped morphologies related to late Quaternary residual megafan depositional systems are common features over wide areas in northern Amazonia. These features were formed by ancient distributary drainage systems that are in great contrast to tributary drainage networks that typify the modern Amazon basin. The surfaces of the Amazonian megafans constitute vegetacional mosaic wetlands with different campinarana types. A fine-scale-resolution investigation is required to provide detailed classification maps for the various campinarana and surrounding forest types associated with the Amazonian megafans. This approach remains to be presented, despite its relevance for analysing the relationship between stages of plant succession and sedimentary dynamics associated with the evolution of megafans. In this work, we develop a methodology for classifying vegetation over a fan-shaped megafan palaeoform from a northern Amazonian wetland. The approach included object-based image analysis (OBIA) and data-mining (DM) techniques combining Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images, land-cover fractions derived by the linear spectral mixing model, synthetic aperture radar (SAR) images, and the digital elevation model (DEM) acquired during the Shuttle Radar Topography Mission (SRTM). The DEM, vegetation fraction, and ASTER band 3 were the most useful parameters for defining the forest classes. The normalized difference vegetation index (NDVI), ASTER band 1, vegetation fraction, and the Advanced Land Observing Satellite (ALOS)/Phased Array type L-band Synthetic Aperture Radar (PALSAR) transmitting and receiving horizontal polarization (HH) and transmitting horizontal and receiving vertical polarization (HV) were all effective in distinguishing the wetland classes campinarana and Mauritia. Tests of statistical significance indicated the overall accuracies and kappa coefficients (κ) of 88% and 0.86 for the final map, respectively. The allocation disagreement coefficient of 5% and a quantity disagreement value of 7% further attested the statistical significance of the classification results. Hence, in addition to water, exposed soil, and deforestation areas, OBIA and DM were successful for differentiating a large number of open (forest, wood, shrub, and grass campinaranas), forest (terra firme, várzea, igapó, and alluvial), as well as Mauritia wetland classes in the inner and outer areas of the studied megafan.     

Memantine‐Loaded PEGylated Biodegradable Nanoparticles for the Treatment of Glaucoma

Glaucoma is a multifactorial neurodegenerative disease associated with retinal ganglion cells (RGC) loss. Increasing reports of similarities in glaucoma and other neurodegenerative conditions have led to speculation that therapies for brain neurodegenerative disorders may also have potential as glaucoma therapies. Memantine is an N‐methyl‐d ‐aspartate (NMDA) antagonist approved for Alzheimer's disease treatment. Glutamate‐induced excitotoxicity is implicated in glaucoma and NMDA receptor antagonism is advocated as a potential strategy for RGC preservation. This study describes the development of a topical formulation of memantine‐loaded PLGA‐PEG nanoparticles (MEM‐NP) and investigates the efficacy of this formulation using a well‐established glaucoma model. MEM‐NPs <200 nm in diameter and incorporating 4 mg mL^?1 of memantine were prepared with 0.35 mg mL^?1 localized to the aqueous interior. In vitro assessment indicated sustained release from MEM‐NPs and ex vivo ocular permeation studies demonstrated enhanced delivery. MEM‐NPs were additionally found to be well tolerated in vitro (human retinoblastoma cells) and in vivo (Draize test). Finally, when applied topically in a rodent model of ocular hypertension for three weeks, MEM‐NP eye drops were found to significantly (p < 0.0001) reduce RGC loss. These results suggest that topical MEM‐NP is safe, well tolerated, and, most promisingly, neuroprotective in an experimental glaucoma model.     

Electrospun polylactic acid-chitosan composite: a bio-based alternative for inorganic composites for advanced application

Fabricating novel materials for biomedical applications mostly require the use of biodegradable materials. In this work biodegradable materials like polylactic acid (PLA) and chitosan (CHS) were used for designing electrospun mats. This work reports the physical and chemical characterization of the PLA–CHS composite, prepared by the electrospinning technique using a mixed solvent system. The addition of chitosan into PLA, offered decrease in fiber diameter in the composites with uniformity in the distribution of fibers with an optimum at 0.4wt% CHS. The fiber formation and the reduction in fiber diameter were confirmed by the SEM micrograph. The inverse gas chromatography and contact angle measurements supported the increase of hydrophobicity of the composite membrane with increase of filler concentration. The weak interaction between PLA and chitosan was confirmed by Fourier transform infrared spectroscopy and thermal analysis. The stability of the composite was established by zeta potential measurements. Cytotoxicity studies of the membranes were also carried out and found that up to 0.6% CHS the composite material was noncytotoxic. The current findings are very important for the design and development of new materials based on polylactic acid-chitosan composites for environmental and biomedical applications.

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Scleral Lens Sensor for Ocular Electrolyte Analysis

The quantitative analysis of tear analytes in point-of-care settings can enable early diagnosis of ocular diseases. Here, a fluorescent scleral lens sensor is developed to quantitatively measure physiological levels of pH, Na⁺, K⁺, Ca²⁺, Mg²⁺, and Zn²⁺ ions. Benzenedicarboxylic acid, a pH probe, displays a sensitivity of 0.12 pH units within pH 7.0–8.0. Crown ether derivatives exhibit selectivity to Na⁺ and K⁺ ions within detection ranges of 0–100 and 0–50 mmol L⁻¹, and selectivities of 15.6 and 8.1 mmol L⁻¹, respectively. A 1,2 bis(o-aminophenoxy)ethane-N,N,-N',N'-tetraacetic-acid-based probe allows Ca²⁺ ion sensing with 0.02–0.05 mmol L⁻¹ sensitivity within 0.50–1.25 mmol L⁻¹ detection range. 5-Oxazolecarboxylic acid senses Mg²⁺ ions, exhibiting a sensitivity of 0.10–0.44 mmol L⁻¹ within the range of 0.5–0.8 mmol L⁻¹. The N-(2-methoxyphenyl)iminodiacetate Zn²⁺ ion sensor has a sensitivity of 1 µmol L⁻¹ within the range of 10–20 µmol L⁻¹. The fluorescent sensors are subsequently multiplexed in the concavities of an engraved scleral lens. A handheld ophthalmic readout device comprising light-emitting diodes (LEDs) and bandpass filters is fabricated to excite as well as read the scleral sensor. A smartphone camera application and an user interface are developed to deliver quantitative measurements with data deconvolution. The ophthalmic system enables the assessment of dry eye severity stages and the differentiation of its subtypes.     

Can official control laboratories quantify reliably fipronil in eggs? Evidence from a proficiency testing round.

A proficiency testing (PT) round dedicated to assess the competence of European Union (EU) National Reference Laboratories (NRLs), EU Official Control Laboratories (OCLs) and OCLs from associated countries for the determination of the insecticide fipronil in eggs is described. The content of the target analytes (sum of fipronil plus its metabolite fipronil sulfone, expressed as fipronil in the PT test material) was set around the regulated Maximum Residue Level (MRL) set by EU legislation. The PT was organised by the European Commission‘s (EC) Directorate General (DG) Joint Research Centre (JRC) – in agreement with the EC DG for Health and Food Safety (SANTE) – following a request by the Belgian Authorities. Eighty-six NRLs and OCLs from 22 EU Member States, Norway, Serbia and Albania participated. The test items used were two materials made of frozen liquid eggs, processed and characterised at the JRC facilities in Geel (Belgium). The majority of the participants (94%) were shown to have a satisfactory performance, expressed as z scores, thus demonstrating the analytical capability of most of the participating NRLs and OCLs to enforce the relevant EU Regulations ((EC) 396/2005 and 1127/2014). Furthermore, 93% of the participants who provided a compliance statement classified, correctly, one of the test items as non-compliant.     

ESBMC 6.1: automated test case generation using bounded model checking

International Journal on Software Tools for Technology Transfer - ESBMC is an SMT-based bounded model checker that provides a bit-precise verification of both C and C++ programs. Bounded model...     

Thermodynamic Stacking Fault Energy,Chemical Composition,and Microstructure Relationship in High-Manganese Steels

Metallurgical and Materials Transactions A - Stacking fault energy (SFE) is related to activating complex high strength and ductility mechanisms such as transformation-induced plasticity and...