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Nevin Manimala Statistics

Investigating the potential of Sentinel-2 configuration to predict the quality of Mediterranean permanent grasslands in open woodlands

Sci Total Environ. 2021 May 29;791:148101. doi: 10.1016/j.scitotenv.2021.148101. Online ahead of print.

ABSTRACT

The assessment of pasture quality in permanent grasslands is essential for their conservation and management, as it can contribute to making real-time decisions for livestock management. In this study, we assessed the potential of Sentinel-2 configuration to predict forage quality in high diverse Mediterranean permanent grasslands of open woodlands. We evaluated the performance of Partial Least Squares Regression (PLS) models to predict crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF) and enzyme digestibility of organic matter (EDOM) by using three different reflectance datasets: (i) laboratory measurements of reflectance of dry and ground pasture samples re-sampled to Sentinel-2 configuration (Spec-lab) (ii) field in-situ measurements of grasslands canopy reflectance resampled to Sentinel-2 configuration (Spec-field); (iii) and Bottom Of Atmosphere Sentinel-2 imagery. For the three reflectance datasets, the models to predict CP content showed moderate performance and predictive ability. Mean R2test = 0.68 were obtained using Spec-lab data, mean R2test decreased by 0.11 with Spec-field and by 0.18 when Sentinel-2 reflectance was used. Statistics for NDF showed worse predictions than those obtained for CP: predictions produced with Spec-lab showed mean R2test = 0.64 and mean RPDtest = 1.73. The mean values of R2test = 0.50 and RPDtest = 1.54 using Sentinel-2 BOA reflectance were marginally better than the values obtained with Spec-field (mean R2test = 0.48, mean RPDtest = 1.43). For ADF and EDOM, only predictions made with Spec-lab produced acceptable results. Bands from the red-edge region, especially band 5, and the SWIR regions showed the highest contribution to estimating CP and NDF. Bands 2, blue and 4, red also seem to be important. The implementation of field spectroscopy in combination with Sentinel-2 imagery proved to be feasible to produce forage quality maps and to develop larger datasets. This study contributes to increasing knowledge of the potential and applicability of Sentinel-2 to predict the quality of Mediterranean permanent grasslands in open woodlands.

PMID:34118678 | DOI:10.1016/j.scitotenv.2021.148101

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Nevin Manimala Statistics

Differential expression of gut miRNAs in idiopathic Parkinson’s disease

Parkinsonism Relat Disord. 2021 Jun 1;88:46-50. doi: 10.1016/j.parkreldis.2021.05.022. Online ahead of print.

ABSTRACT

OBJECTIVE: In the present work, we aimed to investigate the expression of microRNAs (miRNAs) in routine colonic biopsies obtained from patients with idiopathic Parkinson’s disease (PD) and to address their value as a diagnostic biomarker for PD and their mechanistic contribution to PD onset and progression.

METHODS: Patients with PD (n = 13) and healthy controls (n = 17) were prospectively recruited to undergo routine colonic biopsies for cancer screening. Total RNA was extracted from the biopsy material and the expression of miRNAs was quantified by Illumina High-Throughput Sequencing.

RESULTS: Statistical analysis revealed a significant submucosal enrichment of the miRNA hsa-miR-486-5p in colonic biopsies from PD patients compared to the control subjects. The expression of miR-486-5p correlated with age and disease severity as measured by the UPDRS and Hoehn & Yahr scale. miRNA gene target analysis identified 301 gene targets that are affected by miR-486-5p. A follow-up associated target identification and pathway enrichment analysis further determined their role in distinct biological processes in the enteric nervous system (ENS).

INTERPRETATION: Our work demonstrates an enrichment of submucosal miR-486-5p in routine colonic biopsies from PD patients. Our results will support the examination of miR-486-5p as a PD biomarker and help to understand the significance of the miR-486-5p gene targets for PD onset and progression. In addition, our data will support the investigation of the molecular and cellular mechanisms of GI dysfunction in PD.

PMID:34118643 | DOI:10.1016/j.parkreldis.2021.05.022

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Nevin Manimala Statistics

Trends in environmental chemical concentrations in the Canadian population: Biomonitoring data from the Canadian Health Measures Survey 2007-2017

Environ Int. 2021 Jun 9;155:106678. doi: 10.1016/j.envint.2021.106678. Online ahead of print.

ABSTRACT

Ten years of nationally representative biomonitoring data collected between 2007 and 2017 are available from the Canadian Health Measures Survey (CHMS). These data establish baseline environmental chemical concentrations in the general population. Here we sought to evaluate temporal trends in environmental chemical exposures in the Canadian population by quantifying changes in biomarker concentrations measured in the first five two-year cycles of the CHMS. We identified 39 chemicals that were measured in blood or urine in at least three cycles and had detection rates over 50% in the Canadian population. We calculated geometric mean concentrations for each cycle using the survey weights provided. We then conducted analyses of variance to test for linear trends over all cycles. We also calculated the percent difference in geometric means between the first and most recent cycle measured. Of the 39 chemicals examined, we found statistically significant trends across cycles for 21 chemicals. Trends were decreasing for 19 chemicals from diverse chemical groups, including metals and trace elements, phenols and parabens, organophosphate pesticides, per- and polyfluoroalkyl substances, and plasticizers. Significant reductions in chemical concentrations included di-2-ethylhexyl phthalate (DEHP; 75% decrease), perfluorooctane sulfate (PFOS; 61% decrease), perfluorooctanoic acid (PFOA; 58% decrease), dimethylphosphate (DMP; 40% decrease), lead (33% decrease), and bisphenol A (BPA; 32% decrease). Trends were increasing for two pyrethroid pesticide metabolites, including a 110% increase between 2007 and 2017 for 3-phenoxybenzoic acid (3-PBA). No significant trends were observed for the remaining 18 chemicals that included arsenic, mercury, fluoride, acrylamide, volatile organic compounds, and polycyclic aromatic hydrocarbons. National biomonitoring data indicate that concentrations, and therefore exposures, have decreased for many priority chemicals in the Canadian population. Concentrations for other chemical groups have not changed or have increased, although average concentrations remain below thresholds of concern derived from human exposure guidance values. Continued collection of national biomonitoring data is necessary to monitor trends in exposures over time.

PMID:34118655 | DOI:10.1016/j.envint.2021.106678

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Nevin Manimala Statistics

Assessing the effect of herbicide diuron on river biofilm: A statistical model

Chemosphere. 2021 Jun 4;282:131104. doi: 10.1016/j.chemosphere.2021.131104. Online ahead of print.

ABSTRACT

River biofilm communities are the first ones to be exposed to all toxic discharges received via run off from agricultural fields. Hence, changes in river biofilm community structure and growth pattern are considered as indicator of overall health of lotic ecosystem. Toxicants have effect on biofilm biomass, photosynthetic efficiency and chlorophyll a concentrations. Mathematical models may be applied to estimate the overall vigor of riverine ecosystems considering biofilms as indicators. Herein, previous empirical data of Ricart et al. (2009) on long term effects of environmentally relevant concentrations of diuron on biofilm communities of the River Llobregat, Spain was considered as our model inputs. Our objective is to understand the influence of diuron, chlorophyll a concentrations and photosynthetic efficiency on biovolume using a statistical model. The non-linear relationships between biovolume (dependent variable) and diuron, chlorophyll a concentrations and photosynthetic efficiency (independent variables) were represented by constructing three separate basis functions based on day 8 empirical data. Biovolume, due to nonlinear influence as yielded by the basis functions were used in a multiple linear regression model to estimate the net biovolume. Model validation was done based on day 29 empirical data. The experimentally determined biovolume and our model estimated biovolume showed similar trends. Also, diuron and photosynthetic efficiency had significant (p < 0.05) influence on biovolume. Since, the predominance of diatoms as biofilms within periphytic layers is very common in lotic systems, estimation of changes in diatom biovolume will be significant to assess the effect of herbicides. Diatom biovolume of any day (for example day 22) mentioned in the experimental study may be determined by this model, without the requirement of tedious manual biovolume calculation. Our model will be useful in numerous other studies undertaken on the toxic effect of pollutants on biofilms to quickly and accurately estimate the biofilm biovolume.

PMID:34118626 | DOI:10.1016/j.chemosphere.2021.131104

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Nevin Manimala Statistics

Cross-sectional analysis of peripheral blood mononuclear cells in lymphopenic and non-lymphopenic relapsing-remitting multiple sclerosis patients treated with dimethyl fumarate

Mult Scler Relat Disord. 2021 May 7;52:103003. doi: 10.1016/j.msard.2021.103003. Online ahead of print.

ABSTRACT

BACKGROUND: Relapsing-remitting multiple sclerosis (RRMS) is an autoimmune disorder of the central nervous system. Dimethyl Fumarate is a disease-modifying medication used to treat RRMS patients that can induce lymphopenia. We aimed to immunophenotype peripheral blood mononuclear cells (PBMC) in RRMS patients cross-sectionally and examine the characteristics and modifications of lymphopenia over time.

METHODS: Characterization of PBMC was done by multiparametric flow cytometry. Patients had been on treatment for up to 4 years and were grouped into lymphopenic (DMF-L) and non-lymphopenic (DMF-N) patients.

RESULTS: Lymphopenia affected the cell population changes over time, with other patient characteristics (gender, age, and previous treatment status) also having significant effects. In both lymphopenic and non-lymphopenic patients, PBMC percentages were reduced over time. While overall T and B cells frequencies were not affected, males, older patients and untreated patients had significant changes in B cell subpopulations over time. CD4+ to CD8+T cell ratio increased significantly in lymphopenic patients over time. CD4CD8T cell population was similarly reduced in both lymphopenic and non-lymphopenic patients, over time. While the monocyte and NK overall populations were not changed, non-classical monocyte subpopulation decreased over time in lymphopenic patients. We also found CD56CD16+ and CD56CD16 NK cells frequencies changed over time in lymphopenic patients. Immune populations showed correlations with clinical outcomes measured by EDSS and relapse rate. Analysis of the overall immunophenotype showed that, while groups divided by other patient characteristics showed differences, the lymphopenia status overrode these differences, resulting in similar immunophenotype within DMF-L.

CONCLUSIONS: Our data provide evidence that under the same therapy, lymphopenia affects how the immunophenotype changes over time and can override the differences associated with other patient characteristics and possibly mask other significant changes in the immune profile of patients.

PMID:34118574 | DOI:10.1016/j.msard.2021.103003

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Nevin Manimala Statistics

Robotic-assisted total knee arthroplasty improves the outlier of rotational alignment of the tibial prosthesis using 3DCT measurements

Knee. 2021 Jun 9;31:64-76. doi: 10.1016/j.knee.2021.05.009. Online ahead of print.

ABSTRACT

BACKGROUND: The aim of the present study was to compare the accuracy of prosthetic alignment with three-dimensional computed tomography (3DCT) measurements following total knee arthroplasty (TKA) performed using a robotic-assisted surgical technique versus a conventional TKA.

METHODS: 41 TKAs were performed with a handheld robotic-assisted surgical procedure (Robot group) between 2019 and 2020. Another 41 patients underwent TKA with a conventional manual surgical procedure (Manual group) using the same prosthesis. The operation durations between both groups were investigated. 3DCT scans of the entire lower extremities were taken before and after the surgery and femoral and tibial alignments in the coronal, sagittal, and axial planes were measured using computer software. The differences in prosthetic alignment and translation between the preoperative 3DCT plan and postoperative 3DCT image were also measured.

RESULTS: There were no statistically significant differences in the post-operative outliers of the femorotibial angle between the groups. In the tibial-axial plane, the mean of prosthetic alignment in the anteroposterior plane was 4.0° in the Robot group and 6.7° in the Manual group (p < 0.01). The rate of outliers for tibial-axial alignment in the Robot group was significantly less than in the Manual group (p < 0.01). There were no statistically significant differences in prosthetic translation in the proximal-distal, anterior-posterior and medial-lateral orientations between the groups.

CONCLUSIONS: In a radiologic study using 3DCT, robotic-assisted TKA reduced the outliers for rotational alignment of the tibial prosthesis in comparison to conventional TKA, which can lead to improved tracking of the femoral-tibial bearing surfaces.

PMID:34118583 | DOI:10.1016/j.knee.2021.05.009

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Nevin Manimala Statistics

A retrospective evaluation of the indications, complications, and outcomes associated with epicardial pacemakers in 20 cats from a single institution

J Vet Cardiol. 2021 May 13;36:89-98. doi: 10.1016/j.jvc.2021.05.001. Online ahead of print.

ABSTRACT

INTRODUCTION: The objective of this retrospective study was to describe the indications, complications, and long-term outcomes in a group of cats that received an epicardial pacing (EP) system.

ANIMALS: Twenty client-owned cats.

MATERIALS AND METHODS: Medical records were reviewed for signalment, presenting complaint, primary electrocardiogram (ECG) diagnosis, presence of structural heart disease, presence of congestive heart failure (CHF), presence of major or minor complications, and survival time.

RESULTS: The majority of cats were presented for syncope (n = 11), and the most common ECG diagnosis was advanced second-degree atrioventricular block (n = 9). Fifteen cats (15/20, 75%) had one or more major or minor complications. One cat died in the perioperative period as a result of a major complication. None of the variables evaluated were associated with a statistically significant increase in the occurrence of major or minor complications. The most common major complication was loss of ventricular capture (seven instances in six cats), which was successfully treated in all cases by increasing pacemaker output or replacing both the lead and the pulse generator. The most common minor complications were arrhythmias (n = 7) and sensing issues (n = 8). The overall median survival time (MST) was 948 days. No statistical difference in survival time was identified between cats that experienced a major complication and those that did not.

CONCLUSIONS: Although complications were common in this feline population after EP, major and minor complications were successfully treated.

PMID:34118563 | DOI:10.1016/j.jvc.2021.05.001

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Nevin Manimala Statistics

The impact of school exclusion zone planning guidance on the number and type of food outlets in an English local authority: A longitudinal analysis

Health Place. 2021 Jun 9;70:102600. doi: 10.1016/j.healthplace.2021.102600. Online ahead of print.

ABSTRACT

The use of planning policy to manage and create a healthy food environment has become a popular policy tool for local governments in England. To date there has been no evaluation of their short-term impact on the built environment. We assess if planning guidance restricting new fast food outlets within 400 m of a secondary school, influences the food environment in the local authority of Newcastle Upon Tyne, UK. We have administrative data on all food outlets in Newcastle 3 years pre-intervention 2012-2015, the intervention year 2016, and three years’ post-intervention 2016-2019. We employ a difference-in-difference approach comparing postcodes within the school fast food outlet exclusion zone to those outside the fast-food exclusion zones. In the short term (3 years), planning guidance to limit the number of new fast-food outlets in a school exclusion zone did not have a statistically significant impact on the food environment when compared with a control zone.

PMID:34118573 | DOI:10.1016/j.healthplace.2021.102600

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Nevin Manimala Statistics

Unraveling the influence of substrate on the growth rate, morphology and covalent structure of surface adherent polydopamine films

Colloids Surf B Biointerfaces. 2021 Jun 2;205:111897. doi: 10.1016/j.colsurfb.2021.111897. Online ahead of print.

ABSTRACT

Polydopamine (PDA), also known as synthetic melanin, is widely used as a biomimetic anchoring layer for the modification of various solid substrates. PDA is utilized for a wide range of biomedical, sensing and tribological applications, even though the polymer’s precise covalent structure has not been completely revealed yet. Even more, it is not evident to which extent the chemical nature of the substrate, on which the layer is formed, influences and predetermines the covalent structure of resulting PDA. In this contribution, we have studied the growth of PDA using various surface-sensitive techniques such as spectroscopic ellipsometry, atomic force microscopy and X-ray photoelectron spectroscopy. We supplemented grazing angle attenuated total reflection FTIR spectroscopy with multivariate statistical analysis to further gain analytical power. We have particularly focused on the effects of polymerization time and substrate on the PDA structure. We found notable differences in the chemical composition of PDA formed on gold and on surfaces terminated with oxides/reactive hydroxides such as silicon and N-dopped-TiO2 in the early stages of the layer formation. At the later stages of layer formation, a merely unified chemical structure was observed independently on the type of substrate.

PMID:34118533 | DOI:10.1016/j.colsurfb.2021.111897

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Nevin Manimala Statistics

Utility of preoperative CT-based body metrics in relation to postoperative complications in pediatric liver transplant recipients

Liver Transpl. 2021 Jun 12. doi: 10.1002/lt.26205. Online ahead of print.

ABSTRACT

BACKGROUND: Computed tomography (CT) derived body metrics such as skeletal muscle index (SMI), psoas muscle index (PMI), and subcutaneous fat index (ScFI) are measurable components of sarcopenia, frailty, and nutrition. While these body metrics are advocated in adults for predicting postoperative outcomes after liver transplantation (LT), little is known about the value in pediatric populations. This study assessed the relation between preoperative CT-based body metrics and postoperative short-term outcomes in pediatric LT recipients.

METHODS: Patients aged 0-18 years who underwent a primary LT were retrospectively included (N=101, median age 0.5 years, range 0.2-17.1). SMI, PMI, and ScFI were derived from preoperative axial CT slices. Postoperative outcomes and complications within 90 days were correlated with the CT-based body metrics. To classify postoperative infections, the Clavien-Dindo (CD) classification was used. Subgroup analyses were performed for age groups (<1, 1-10, and >10 years old). An optimal threshold for test performance was defined using Youden’s J-statistic and receiver operating characteristic curve as appropriate.

RESULTS: ScFI was significantly (P=0.001) correlated with moderate to severe postoperative infections (CD grade 3-5) in children <1 year old, with the optimal ScFI threshold being ≤27.1 cm2 /m2 (sensitivity 80.4% and specificity 77.8%). A weak negative correlation between SMI and the total duration of hospital stay (R=-0.33, P=0.010) and intensive care unit stay (R=-0.32, P 0.013) was observed in children <1 year old. No other associations between CT-based body metrics and postoperative outcomes were shown.

CONCLUSIONS: In children <1 year old with cirrhotic liver disease undergoing LT, pre-operative CT-based body metrics were correlated with moderate to severe postoperative infections (ScFI), and with longer duration of hospital and ICU stay (SMI), and thus can be considered important tools for pre-LT risk assessment.

PMID:34118133 | DOI:10.1002/lt.26205