Category: Statistics

J Mech Behav Biomed Mater. 2021 Aug 12;123:104728. doi: 10.1016/j.jmbbm.2021.104728. Online ahead of print.

ABSTRACT

Artificial intelligence (AI) and machine learning (ML) are fascinating interdisciplinary scientific domains where machines are provided with an approximation of human intelligence. The conjecture is that machines are able to learn from existing examples, and employ this accumulated knowledge to fulfil challenging tasks such as regression analysis, pattern classification, and prediction. The horse biomechanical models have been identified as an alternative tool to investigate the effects of mechanical loading and induced deformations on the tissues and structures in humans. Many reported investigations into bone fatigue, subchondral bone damage in the joints of both humans and animals, and identification of vital parameters responsible for retaining integrity of anatomical regions during normal activities in all species are heavily reliant on equine biomechanical research. Horse racing is a lucrative industry and injury prevention in expensive thoroughbreds has encouraged the implementation of various measurement techniques, which results in massive data generation. ML substantially accelerates analysis and interpretation of data and provides considerable advantages over traditional statistical tools historically adopted in biomechanical research. This paper provides the reader with: a brief introduction to AI, taxonomy and several types of ML algorithms, working principle of a feedforward artificial neural network (ANN), and, a detailed review of the applications of AI, ML, and ANN in equine biomechanical research (i.e. locomotory system function, gait analysis, joint and bone mechanics, and hoof function). Reviewing literature on the use of these data-driven tools is essential since their wider application has the potential to: improve clinical assessments enabling real-time simulations, avoid and/or minimize injuries, and encourage early detection of such injuries in the first place.

PMID:34412024 | DOI:10.1016/j.jmbbm.2021.104728

Folia Phoniatr Logop. 2021 Aug 19:1-10. doi: 10.1159/000516225. Online ahead of print.

ABSTRACT

OBJECTIVE: The objective of this study is quantitative assessment of nasalance for skeletal Class I (normative values), Class II, and III malocclusion in the English language for the North Indian population and to compare the normative values with the nasalance scores obtained from individuals with skeletal Class II and III malocclusion and to evaluate the normative values as a function of gender.

MATERIAL AND METHODS: The study was conducted on a total sample of 200 patients with 100, 50, and 50 in group 1 (control group, Skeletal Class I), group 2 (Skeletal Class II), and group 3 (Skeletal Class III), respectively. ANB angle (anteroposterior angle formed by point A, nasion, and point B) measured on lateral cephalogram was used to categorize the patients into 3 groups. The normative nasalance scores were compared for males and females in the control group. The nasalance scores of skeletal Class II and III subjects were compared to the combined normative scores of the control group. The NasalView was used for the objective assessment of nasalance. Oral syllables (/pa/and/pi/), nasal syllables (/ma/and/mi/), and 3 passages (Zoo passage, Rainbow passage, and Nasal sentences) were used to determine the nasalance scores.

RESULTS: The intragroup comparison of nasalance scores in group 1 showed statistically significant differences for different stimuli. The gender-related comparison showed no statistically significant differences in nasalance scores. The intergroup comparison of nasalance scores for skeletal malocclusion showed no statistically significant differences for different stimuli except statistically significant lower nasalance values for nasal sentences in group 3 compared to the control group.

CONCLUSION: The study concluded that the nasalance scores for nasal sentences in skeletal Class III malocclusion were significantly lower than in the control group and were not statistically significant between the 3 groups for all other stimuli.

PMID:34412052 | DOI:10.1159/000516225

J Inorg Biochem. 2021 Aug 8;224:111565. doi: 10.1016/j.jinorgbio.2021.111565. Online ahead of print.

ABSTRACT

Despite increasing use of silver nanoparticles (AgNPs) in different medicinal products, knowledge about their effects on hemostasis and platelets functionality is still scarce. Published scientific reports provide neither data on oxidative stress response of platelets to AgNPs nor information about the effects of AgNPs physicochemical properties on functionality and activation of platelets. This study aimed to explore the role of AgNPs surface functionalization on cell viability, particle uptake, oxidative stress response, and activation of platelets. Small sized, spherical AgNPs were surface functionalized by negatively charged sodium bis(2-ethylhexyl) sulphosuccinate (AOT), neutral polymer polyvinylpyrrolidone (PVP), positively charged polymer poly-l-lysine (PLL) and bovine serum albumin (BSA). Platelet viability, activation and particle uptake were evaluated by flow cytometry. Oxidative stress response was evaluated by measuring the levels of intracellular glutathione (GSH), peroxy and superoxide radicals using assays based on fluorescence dies. Cytotoxicity and uptake of AgNPs to platelets were found to be dose-dependent in a following order PLL-AgNP >> > BSA-AgNP > AOT-AgNP > PVP-AgNP. Particle internalization was further confirmed by transmission electron microscopy. Treatment of platelets with AgNPs induced superoxide radical formation, depletion of GSH and hyperpolarization of the mitochondrial membrane. Small, but statistically significant increase of P-selectin expression in cells treated with all AgNPs compared to non-treated controls evidenced AgNPs-induced activation of platelets. Increased PAC-1 expression was found only in platelets treated with PLL-AgNPs. Obtained results demonstrate that different surface decoration of AgNPs determines their biological effects on platelets highlighting the importance of careful design of AgNPs-based medicinal products regarding their biocompatibility and functionality.

PMID:34411938 | DOI:10.1016/j.jinorgbio.2021.111565

Mar Pollut Bull. 2021 Aug 16;172:112851. doi: 10.1016/j.marpolbul.2021.112851. Online ahead of print.

ABSTRACT

The environmental status of three Intermittently Closed and Open Lakes and Lagoons (ICOLLs) (Manly, Curl Curl and Dee Why Lagoons) in northern Sydney (Australia) were assessed using sedimentary metals. Results identified the highest sedimentary metal enrichment in the Australian central east coast estuaries, with only a moderate ecological risk. A comparison with surficial sediment concentrations from 1996 to 2008 indicated declining metal concentrations, which is largely supported by subsurface metals data. Extensive low-lying areas of the catchments were historically reclaimed by infilling wetlands, which may have resulted in contaminated groundwater influx to the lagoons. An analysis of the sedimentary metals mix in lagoons surrounded by extensive infilling and estuaries with minor reclamation were statistically distinct. ICOLLs are environmentally sensitive due to large catchment/estuary ratios and restricted access to the ocean. A full set of baseline data is provided to support future monitoring of anthropogenic impacts on the system.

PMID:34411956 | DOI:10.1016/j.marpolbul.2021.112851

Chemosphere. 2021 Aug 13;286(Pt 3):131885. doi: 10.1016/j.chemosphere.2021.131885. Online ahead of print.

ABSTRACT

In Istanbul, which is surrounded by the sea on 3 sides, thousands of tons of seaweed that have formed naturally every year are washed ashore. In this study, the usability of these seaweeds which are landfilling already in fertilizer production was discussed. Liquid fertilizer production was carried out using 3 different physical and 4 different biological methods, and the produced fertilizers were diluted in 5 different ratios (1%, 10%, 25%, 50%, and 100%) and applied to cress seed. The effect of each fertilizer and its concentration on seed germination, plant length, number of leaves, and soil moisture-holding capacity was studied. The data obtained were analyzed using Response Surface Methodology (RSM). The results showed that if seaweed was fermented with anaerobic seed sludge for 15 days and applied to the plant by diluting it to 15-25%, plant growth will be supported at an optimum level. It has also been shown that if the seaweed was fermented with yeast culture for 18 days and fed with a concentration of >90%, the moisture-holding capacity of the soil could be increased by up to 27%.

PMID:34411930 | DOI:10.1016/j.chemosphere.2021.131885

Forensic Sci Int. 2021 Jul 4;326:110897. doi: 10.1016/j.forsciint.2021.110897. Online ahead of print.

ABSTRACT

Diatoms are a useful form of environmental trace evidence, yielding a circumstantial link between persons and scenes of forensic interest. A developing empirical research base has sought to understand those factors affecting the transfer and persistence of freshwater diatoms on clothing and footwear surfaces. Although an initial study has demonstrated that diatoms can persist on clothing following weeks of wear, no previous research has explored the temporal dynamics of a persistent species assemblage over timescales pertinent to forensic investigations. This study therefore aimed to determine if: (1) valve morphology (size and shape) influences diatom persistence, (2) the relative abundance of taxa within an assemblage affects retention, and (3) a persistent diatom assemblage retrieved from clothing after one month can reliably be compared to the site of initial transfer. To build on previous research findings which highlighted the impact of substrate and environmental seasonality on diatom transfer and persistence, here, nine clothing materials were tested in spring before a seasonal comparison in the winter. Fabric swatches were immersed in a freshwater river, worn attached to clothing, and subsamples retrieved at regular intervals (hours, days, weeks) up to one month post-immersion. Diatoms were extracted using a H₂O₂ technique and analysed via microscopy. The results indicated that smaller diatoms (< 10 µm) are retained in significantly greater abundance, with no statistically significant difference between centric and pennate diatom loss over time. Although a persistent species assemblage was relatively stable over the one month of wear, significant differences were identified between clothing substrate in the spring and between the seasonal samples. The most abundant environmental taxa were consistently identified in the forensic samples, with greater variability attributed to the retention of relatively less common species. The findings suggest that, despite a loss in the abundance and species-richness of diatoms retrieved from clothing over time, a persistent assemblage may provide a useful circumstantial link to the site of initial transfer. The complex relationships between clothing type, environmental seasonality, and time since wear on retention, emphasise the need for diatom trace evidence to be carefully interpreted within an exclusionary framework, and the significance of any casework findings to be determined with reference to empirical evidence bases.

PMID:34411937 | DOI:10.1016/j.forsciint.2021.110897

Curr Opin Neurobiol. 2021 Aug 16;70:64-73. doi: 10.1016/j.conb.2021.07.003. Online ahead of print.

ABSTRACT

Modern recording technologies now enable simultaneous recording from large numbers of neurons. This has driven the development of new statistical models for analyzing and interpreting neural population activity. Here, we provide a broad overview of recent developments in this area. We compare and contrast different approaches, highlight strengths and limitations, and discuss biological and mechanistic insights that these methods provide.

PMID:34411907 | DOI:10.1016/j.conb.2021.07.003

Chemosphere. 2021 Aug 5;286(Pt 3):131786. doi: 10.1016/j.chemosphere.2021.131786. Online ahead of print.

ABSTRACT

Phosphate rock (PR) is the main source of phosphorous used in fertilizers for Colombian soils. In many regions of Colombia, PR is applied directly to the soil, which affects eutrophication problems and phosphorus losses due to runoff, because to the low solubility of phosphorus in this georesource. In this article, phosphate rock samples from Colombia were treated with ethylenediamine tetra-acetic acid disodium salt dihydrate (2Na-EDTA) at different concentrations. PR obtained from the Media Luna Mine, located in Aipe, Huila (Colombia), was characterized using Infrared Spectroscopy, X-ray Diffraction and Scanning Electron Microscopy. Carbonate fluorapatite Ca_9.74(PO₄)_5.45F_2.05(CO₃)_0.53 (0.5%-61.5 %), hydroxyapatite – Ca₅(PO₄)₃OH (26.6 %-84.0 %) and quartz- SiO₂ (13.2 %) were the minerals found in the largest composition in the two samples of PR. The PR was crushed to powder (~125 μm) and it was treated with disodium EDTA dihydrate solutions at different concentrations [0.0025-0.1000 M]. Water-soluble phosphate was determined by UV-Vis spectrophotometry based on the ASTM -4500P method. The modified absolute solubility index (ASI*) was calculated for each EDTA treatment used in the phosphate rock, considering the total phosphorus solubilized in H₂SO₄ (40 % v/v) at 30 °C. The statistical analysis showed that there were significant differences between the treatments used, where (16.87 %) was presented highest ASI* for the treatment with 2Na-EDTA (0.353 M).

PMID:34411927 | DOI:10.1016/j.chemosphere.2021.131786

J Perinat Med. 2021 Aug 19. doi: 10.1515/jpm-2021-0132. Online ahead of print.

ABSTRACT

OBJECTIVES: We aimed to evaluate the cardiotocograph (CTG) traces of 224 women infected with novel coronavirus 2019 (COVID-19) and analyze whether changes in the CTG traces are related to the severity of COVID-19.

METHODS: We designed a prospective cohort study. Two-hundred and twenty-four women who had a single pregnancy of 32 weeks or more, and tested positive for SARS-CoV-2 were included. Clinical diagnosis and classifications were made according to the Chinese management guideline for COVID-19 (version 6.0). Patients were classified into categories as mild, moderate, severe and the CTG traces were observed comparing the hospital admission with the third day of positivity.

RESULTS: There was no statistically significant relationship between COVID-19 severity and CTG category, variability, tachycardia, bradycardia, acceleration, deceleration, and uterine contractility, Apgar 1st and 5th min.

CONCLUSIONS: Maternal COVID-19 infection can cause changes that can be observed in CTG. Regardless of the severity of the disease, COVID-19 infection is associated with changes in CTG. The increase in the baseline is the most obvious change.

PMID:34411469 | DOI:10.1515/jpm-2021-0132

Angew Chem Int Ed Engl. 2021 Aug 19. doi: 10.1002/anie.202109201. Online ahead of print.

ABSTRACT

Co 3 O 4 nanocubes are evaluated concerning their intrinsic electrocatalytic activity towards the oxygen evolution reaction (OER) by means of single-entity electrochemistry. Scanning electrochemical cell microscopy (SECCM) provides data on the electrocatalytic OER activity from several individual measurement areas covering one Co 3 O 4 nanocube. We were able to evaluate a comparatively high number of individual particles with sufficient statistical reproducibility. Single-particle-on-nanoelectrode measurements performed with the same Co 3 O 4 nanocubes provide, on the one hand, an accelerated stress test at highly alkaline conditions with current densities of up to 5.5 A∙cm -2 , and on the other hand, allows to derive TOF values of up to 2.8 x 10 4 s -1 at 1.92 V vs. RHE for surface Co atoms of a single cubic nanoparticle. Obtaining such current densities combined with identical-location transmission electron microscopy allows monitoring structural changes during electrocatalysis, specifically the formation of an oxy(hydroxide) surface layer. Combining the information from two independent single-entity electrochemistry measurements provides the basis for elucidating structure-activity relations of single electrocatalyst nanoparticles with well-define surface structure.

PMID:34411401 | DOI:10.1002/anie.202109201