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Nevin Manimala Statistics

Multivariate random forest prediction of poverty and malnutrition prevalence

PLoS One. 2021 Sep 8;16(9):e0255519. doi: 10.1371/journal.pone.0255519. eCollection 2021.

ABSTRACT

Advances in remote sensing and machine learning enable increasingly accurate, inexpensive, and timely estimation of poverty and malnutrition indicators to guide development and humanitarian agencies’ programming. However, state of the art models often rely on proprietary data and/or deep or transfer learning methods whose underlying mechanics may be challenging to interpret. We demonstrate how interpretable random forest models can produce estimates of a set of (potentially correlated) malnutrition and poverty prevalence measures using free, open access, regularly updated, georeferenced data. We demonstrate two use cases: contemporaneous prediction, which might be used for poverty mapping, geographic targeting, or monitoring and evaluation tasks, and a sequential nowcasting task that can inform early warning systems. Applied to data from 11 low and lower-middle income countries, we find predictive accuracy broadly comparable for both tasks to prior studies that use proprietary data and/or deep or transfer learning methods.

PMID:34495951 | DOI:10.1371/journal.pone.0255519

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Nevin Manimala Statistics

The induction of preterm labor in rhesus macaques is determined by the  strength of immune response to intrauterine infection

PLoS Biol. 2021 Sep 8;19(9):e3001385. doi: 10.1371/journal.pbio.3001385. Online ahead of print.

ABSTRACT

Intrauterine infection/inflammation (IUI) is a major contributor to preterm labor (PTL). However, IUI does not invariably cause PTL. We hypothesized that quantitative and qualitative differences in immune response exist in subjects with or without PTL. To define the triggers for PTL, we developed rhesus macaque models of IUI driven by lipopolysaccharide (LPS) or live Escherichia coli. PTL did not occur in LPS challenged rhesus macaques, while E. coli-infected animals frequently delivered preterm. Although LPS and live E. coli both caused immune cell infiltration, E. coli-infected animals showed higher levels of inflammatory mediators, particularly interleukin 6 (IL-6) and prostaglandins, in the chorioamnion-decidua and amniotic fluid (AF). Neutrophil infiltration in the chorio-decidua was a common feature to both LPS and E. coli. However, neutrophilic infiltration and IL6 and PTGS2 expression in the amnion was specifically induced by live E. coli. RNA sequencing (RNA-seq) analysis of fetal membranes revealed that specific pathways involved in augmentation of inflammation including type I interferon (IFN) response, chemotaxis, sumoylation, and iron homeostasis were up-regulated in the E. coli group compared to the LPS group. Our data suggest that the intensity of the host immune response to IUI may determine susceptibility to PTL.

PMID:34495952 | DOI:10.1371/journal.pbio.3001385

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Nevin Manimala Statistics

Nectar productivity of Tilia amurensis in a broadleaved-conifer mixed forest in Changbai Mountains, China

Ying Yong Sheng Tai Xue Bao. 2020 Aug;31(8):2500-2506. doi: 10.13287/j.1001-9332.202008.008.

ABSTRACT

Tilia amurensis is one of (co-)dominant species in the broadleaved-conifer mixed forest in Northeast China, with high commercial and nectariferous values. We estimated the quantity of nectar secretion from individual trees to population or stand levels based on observation and statistical analysis. An equation for individual-tree nectar secretion was established, which was used to estimate nectar quantity at the stand level. We analyzed the relationships between nectar secretion and basal area or stem volume. The booming time for single flower was in average 6-8 days, with a nectar secretion period of about five days. The quantity for the entire period was estimated at 8.58 mg per flower. Sugar contents in the nectar, average 37.7%, showed diurnal variations, being high in the mid-noon and low in the early morning and late afternoon. The average diameter (DBH) of the species was approximately 40 cm, which was estimated to possess as much as 18×104 single flowers and 1.56 kg (or pure sugar 0.588 kg) of nectar. At the stand level, the nectar production potential was 79-147 kg (or 0.0686-0.1285 m3, pure sugar 29.78-55.42 kg) per hectare. There was a close correlation between nectar quantity and basal area or timber volume at both individual and stand levels, which could be used to estimate the nectar quantity for macro-scale forest area based on inventory data.

PMID:34494770 | DOI:10.13287/j.1001-9332.202008.008

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Nevin Manimala Statistics

Ecological benefits of transfer payment of natural forest protection projects and their impact mechanisms

Ying Yong Sheng Tai Xue Bao. 2020 Aug;31(8):2663-2670. doi: 10.13287/j.1001-9332.202008.009.

ABSTRACT

The policy of natural forest protection project (NFPP) is of great significance to the protection and restoration of natural forests. It remains unclear about how to play the role of NFPP transfer payment in forest ecological benefits. Based on panel data of “China Forestry Statistical Yearbook” from 2011 to 2017, we used forest management area and forest tending area as indicators to measure forest ecological benefits, and used spatial lag model and intermediary effect model to analyze the impacts of the transfer payment funds of NFPP on the forest ecological benefits in key state-owned forest areas. The results showed that forest ecological benefits in the key state-owned forest areas in the second phase of NFPP had improved year by year. There was a significant spatial spillover effect of forest ecological benefits of forestry bureaus. The transfer funds of NFPP had a significant positive effect on the ecological benefits of forest resources in key state-owned forest areas. There was a partial intermediary effect between the improvement of human capital and the establishment of first-line management and protection stations. The central government should increase investment in the transfer payment funds of NFPP. Forest administrations should increase the proportion of funds used in improving human capital and establishing first-line management and protection stations.

PMID:34494789 | DOI:10.13287/j.1001-9332.202008.009

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Nevin Manimala Statistics

Developing the geographic classification for health, a rural-urban classification for New Zealand health research and policy: A research protocol

Aust J Rural Health. 2021 Sep 8. doi: 10.1111/ajr.12778. Online ahead of print.

ABSTRACT

INTRODUCTION: Rural-urban health inequities, exacerbated by deprivation and ethnicity, have been clearly described in the international literature. To date, the same inequities have not been as clearly demonstrated in Aotearoa New Zealand despite the lower socioeconomic status and higher proportion of Māori living in rural towns. This is ascribed by many health practitioners, academics and other informed stakeholders to be the result of the definitions of ‘rural’ used to produce statistics.

AIMS: To outline a protocol to produce a ‘fit-for-health purpose’ rural-urban classification for analysing national health data. The classification will be designed to determine the magnitude of health inequities that have been obscured by use of inappropriate rural-urban taxonomies.

METHODS: This protocol paper outlines our proposed mixed-methods approach to developing a novel Geographic Classification for Health. In phase 1, an agreed set of community attributes will be used to modify the new Statistics New Zealand Urban Accessibility Classification into a more appropriate classification of rurality for health contexts. The Geographic Classification for Health will then be further developed in an iterative process with stakeholders including rural health researchers and members of the National Rural Health Advisory Group, who have a comprehensive ‘on the ground’ understanding of Aotearoa New Zealand’s rural communities and their attendant health services. This protocol also proposes validating the Geographic Classification for Health using general practice enrolment data. In phase 2, the resulting Geographic Classification for Health will be applied to routinely collected data from the Ministry of Health. This will enable current levels of rural-urban inequity in health service access and outcomes to be accurately assessed and give an indication of the extent to which older classifications were masking inequities.

PMID:34494690 | DOI:10.1111/ajr.12778

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Nevin Manimala Statistics

Diagnostic and prognostic plasma biomarkers for preclinical Alzheimer’s disease

Alzheimers Dement. 2021 Sep 8. doi: 10.1002/alz.12447. Online ahead of print.

ABSTRACT

INTRODUCTION: This study involved a parallel comparison of the diagnostic and longitudinal monitoring potential of plasma glial fibrillary acidic protein (GFAP), total tau (t-tau), phosphorylated tau (p-tau181 and p-tau231), and neurofilament light (NFL) in preclinical Alzheimer’s disease (AD).

METHODS: Plasma proteins were measured using Simoa assays in cognitively unimpaired older adults (CU), with either absence (Aβ-) or presence (Aβ+) of brain amyloidosis.

RESULTS: Plasma GFAP, t-tau, p-tau181, and p-tau231 concentrations were higher in Aβ+ CU compared with Aβ- CU cross-sectionally. GFAP had the highest effect size and area under the curve (AUC) in differentiating between Aβ+ and Aβ- CU; however, no statistically significant differences were observed between the AUCs of GFAP, p-tau181, and p-tau231, but all were significantly higher than the AUC of NFL, and the AUC of GFAP was higher than the AUC of t-tau. The combination of a base model (BM), comprising the AD risk factors, age, sex, and apolipoprotein E gene (APOE) ε4 status with GFAP was observed to have a higher AUC (>90%) compared with the combination of BM with any of the other proteins investigated in the current study. Longitudinal analyses showed increased GFAP and p-tau181 in Aβ+ CU and increased NFL in Aβ- CU, over a 12-month duration. GFAP, p-tau181, p-tau231, and NFL showed significant correlations with cognition, whereas no significant correlations were observed with hippocampal volume.

DISCUSSION: These findings highlight the diagnostic and longitudinal monitoring potential of GFAP and p-tau for preclinical AD.

PMID:34494715 | DOI:10.1002/alz.12447

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Nevin Manimala Statistics

Bayesian workflow for disease transmission modeling in Stan

Stat Med. 2021 Sep 8. doi: 10.1002/sim.9164. Online ahead of print.

ABSTRACT

This tutorial shows how to build, fit, and criticize disease transmission models in Stan, and should be useful to researchers interested in modeling the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and other infectious diseases in a Bayesian framework. Bayesian modeling provides a principled way to quantify uncertainty and incorporate both data and prior knowledge into the model estimates. Stan is an expressive probabilistic programming language that abstracts the inference and allows users to focus on the modeling. As a result, Stan code is readable and easily extensible, which makes the modeler’s work more transparent. Furthermore, Stan’s main inference engine, Hamiltonian Monte Carlo sampling, is amiable to diagnostics, which means the user can verify whether the obtained inference is reliable. In this tutorial, we demonstrate how to formulate, fit, and diagnose a compartmental transmission model in Stan, first with a simple susceptible-infected-recovered model, then with a more elaborate transmission model used during the SARS-CoV-2 pandemic. We also cover advanced topics which can further help practitioners fit sophisticated models; notably, how to use simulations to probe the model and priors, and computational techniques to scale-up models based on ordinary differential equations.

PMID:34494686 | DOI:10.1002/sim.9164

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Nevin Manimala Statistics

The effect of atmospheric cold plasma on the dentinal tubule penetration of calcium silicate-based sealer used with different obturation techniques: A confocal laser scanning microscopy study

Aust Endod J. 2021 Sep 8. doi: 10.1111/aej.12564. Online ahead of print.

ABSTRACT

The aim of this study was to evaluate the effect of atmospheric cold plasma (ACP) on dentinal tubule penetration of EndoSequence BC. Sixty premolars were divided into four groups according to the obturation technique and plasma treatment. Root canals were filled with single cone in Group 1 (SC), single cone after ACP application in Group 2 (SC-P), warm vertical compaction in Group 3 (WVC), warm vertical compaction after ACP application in Group 4 (WVC-P). Horizontal sections were imaged using confocal laser scanning microscopy. The maximum penetration and percentage of penetration values were measured. These data were statistically analysed (P < 0.01). In the coronal region, the percentage of penetration values were higher in SC-P and WVC-P than in SC and WVC. In the middle region, SC-P and SC showed a higher penetration percentage than WVC and WVC-P. In the apical region, WVC showed a higher percentage of penetration value than SC-P, WVC-P and SC did. Maximum penetration of WVC was higher than of SC and SC-P. Within the limitations of this study, ACP improved the percentage of penetration values of EndoSequence BC when used with single-cone technique.

PMID:34494689 | DOI:10.1111/aej.12564

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Nevin Manimala Statistics

Assessment of bacterial and dye penetration through post/crown interim restorations while under simulated masticatory load

Aust Endod J. 2021 Sep 8. doi: 10.1111/aej.12561. Online ahead of print.

ABSTRACT

The aim was to compare two temporary cements to determine which resisted bacterial and dye penetration under temporary posts/cores/crowns subjected to simulated masticatory function. Forty-six single canal human tooth roots were prepared for posts/crowns. A cotton pellet and Cavit were placed in each post space. Temporary posts/cores/crowns were cemented with Intermediate Restorative Material (IRM) (n = 23) or Tempocem (n = 23). Specimens were sterilised, then immersed in a mixture of Streptococcus gordonii and India ink, and subjected to 4 weeks simulated mastication. Dye penetration was assessed by visually inspecting the cotton pellets. Bacterial penetration was determined by placing the pellets into sterile broth and by plating them onto agar plates to confirm S. gordonii growth. There was no statistically significant difference between the cements and the dependent variables of bacterial and dye penetration. Hence, both cements are good options to cement temporary posts/cores/crowns during endodontic treatment of anterior teeth.

PMID:34494675 | DOI:10.1111/aej.12561

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Nevin Manimala Statistics

Novel strategy for applying hierarchical density-based spatial clustering of applications with noise towards spectroscopic analysis and detection of melanocytic lesions

Melanoma Res. 2021 Sep 7. doi: 10.1097/CMR.0000000000000771. Online ahead of print.

ABSTRACT

Advancements in dermoscopy techniques have elucidated identifiable characteristics of melanoma which revolve around the asymmetrical constitution of melanocytic lesions consequent of unfettered proliferative growth as a malignant lesion. This study explores the applications of hierarchical density-based spatial clustering of applications with noise (HDBSCAN) in terms of the direct diagnostic implications of applying agglomerative clustering in the spectroscopic analysis of malignant melanocytic lesions and benign dermatologic spots. 100 images of benign (n = 50) and malignant moles (n = 50) were sampled from the International Skin Imaging Collaboration Archive and processed through two separate Python algorithms. The first of which deconvolutes the three-digit tupled integer identifiers of pixel color in image composition into three separate matrices corresponding to the red, green and blue color channel. Statistical characterization of integer variance was utilized to determine the optimal channel for comparative analysis between malignant and benign image groups. The second applies HDBSCAN to the matrices, identifying agglomerative clustering in the dataset. The results indicate the potential diagnostic applications of HDBSCAN analysis in fast-processing dermoscopy, as optimization of clustering parameters according to a binary search strategy produced an accuracy of 85% in the classification of malignant and benign melanocytic lesions.

PMID:34494605 | DOI:10.1097/CMR.0000000000000771