Tag: statistics

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

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

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

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

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

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

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

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

Int J Cancer. 2021 Sep 8. doi: 10.1002/ijc.33799. Online ahead of print.

ABSTRACT

The incidence of uterine corpus cancer has been increasing globally due to increase in obesity. However, a detailed analysis of long-term epidemiological trends of corpus cancer in Japan, where obesity is relatively minimal, has not been conducted. In this retrospective, population-based study using the Osaka Cancer Registry, we analyzed 15,255 cases of corpus neoplasia registered between 1977 and 2016. We determined the age-standardized incidence, mortality, relative survival, and conditional survival rates, and the treatment trends for corpus cancer over the last 40 years in Japan. The age-standardized incidence rate of corpus cancer increased sharply in 2000-2011 (APC = 9.9, 95% CI: 8.4 to 11.3), whereas the mortality rate trended to a much more modest increase (APC = 3.3, 95% CI: 2.7 to 3.8). Compared with 1977-2000, 10-year survival rates for post-2000 cases of localized and regional cases significantly improved (from 87.7% (95%CI: 85.8 to 89.4) to 94.2% (95%CI: 92.7 to 95.7), and from 47.5% (95%CI: 43.3 to 51.6) to 64.4% (95%CI: 61.0 to 67.6), respectively). This was largely associated with the significant increase in the percentage of localized and regional patients who received chemotherapy instead of radiation as an adjuvant therapy combined to surgery (p<0.001 for both). We found that each histological type (endometrioid carcinoma, serous carcinoma, clear cell carcinoma and carcinosarcoma) has different characteristics of trend of age-standardized incidence rate, relative survival, and distribution of extent of disease. In endometrioid carcinoma, the age-standardized incidence rate increased consistently after 1990, but the rate of increase was decreasing after 1997. This article is protected by copyright. All rights reserved.

PMID:34494658 | DOI:10.1002/ijc.33799

Niger Postgrad Med J. 2021 Apr-Jun;28(2):126-132. doi: 10.4103/npmj.npmj_578_21.

ABSTRACT

INTRODUCTION: Existing evidence suggests that barotitis media (BM) is common among air travellers, and it has the potential to cause severe discomfort and sometimes permanent hearing and balance deficits. It has not been studied in Nigeria.

OBJECTIVE: This study aimed to assess the pre-air travel health-seeking behaviour, prevalence of BM, knowledge of BM and its associated factors among a cohort of outpatients with a history of recent air travel in Kano, Nigeria.

MATERIALS AND METHODS: This questionnaire-based survey involved 97 participants systematically and proportionately selected from adult patients or caregivers of children with recent air travel history attending two outpatients clinics over 7 weeks. Information on biodata, pre-air travel advice-seeking behaviours, air travel experience and BM knowledge were obtained. Data were analysed using the descriptive statistical methods, Chi-square or Fisher’s exact tests and odds ratio (OR).

RESULTS: Most participants were male (54.6%) with tertiary education (87.6%); the prevalence of BM was 44.3% (43/97). Only 2.1% (2/97) had ever sought pre-air travel advice from a doctor; 83.5% (81/97) had heard of BM before; 42% had adequate knowledge of BM. Employment status (Fisher’s exact, P = 0.001), clinic at recruitment (Fisher’s exact, P = 0.00008), duration of last flight (Fisher’s exact, P = 0.0001) and persistent ear-pain after landing (Fisher’s exact, P = 0.001) were significantly associated with participants’ knowledge of BM. Persistent ear-pain after landing was the predictor of BM knowledge (OR = 0.04, 95% confidence interval [0.002-0.67], P = 0.025).

CONCLUSION: The BM knowledge level of this cohort suggests the need for further studies to ascertain the complete picture and justify improved pretravel education of air travellers in our setting.

PMID:34494599 | DOI:10.4103/npmj.npmj_578_21