Tag: statistics

J Hist Behav Sci. 2021 Oct 8. doi: 10.1002/jhbs.22145. Online ahead of print.

ABSTRACT

Anders N. Kiaer (1838-1919), the director of Norway’s Central Bureau of Statistics between 1877 and 1913, was the foremost promoter, at the turn of the 20th century, of the rebirth of what came to be known as the “representative method” or sample survey. His advocacy of a methodology that had been abandoned at the beginning of the 19th century in favor of complete enumeration (the census) provoked a controversy at the International Statistical Institute (ISI) when he first presented it in 1895. Yet, it was “recommended” in fairly short order, by 1903. This was the result of a convergence of factors that prevented the dispute from degenerating into a full-blown conflict and facilitated continuing the discussion while preventing a potential break-up of the association. To understand how this came about, the paper examines (1) the role of the historical background from which the ISI emerged; (2) the epistemic beliefs that informed the ISI members in their daily professional practice; (3) the social structure of the ISI and its “ethos”; (4) the professional standing Kiaer enjoyed within the international statistical community. This is a case-study in the sociology of how and why some scientific practices initially seen as “dangerous” gain acceptance and become part of science’s lore.

PMID:34624935 | DOI:10.1002/jhbs.22145

J Radiol Prot. 2021 Oct 8. doi: 10.1088/1361-6498/ac2e0a. Online ahead of print.

ABSTRACT

This study investigated the variability of indoor radon concentrations in 518,100 homes in the UK. The statistical analysis included measurements in 395,720 homes with downstairs living rooms and upstairs bedrooms. The radon concentration in these bedrooms was found to be on average 63% of the living room value. The analysis of 122,380 homes with living rooms and bedrooms situated on the same floor found that there is a small difference in radon concentration of 9% between the two rooms. The results showed that the ratios of the living room to bedroom radon concentrations were approximately lognormally distributed. The geometric mean of the ratio was found to be 1.6 for rooms situated on different storeys and 1.1 for rooms situated on the same floor. It was found that house characteristics and energy efficiency measures affect the distribution of radon within homes. Detached houses and those with suspended floors had higher radon levels in their upstairs bedroom, 66.7 % and 76.9 % of the downstairs living room values, respectively. For homes built between 1993 and 2007, the bedroom to living room ratio increased from 58.8 % to 76.9 % due to the increased airtightness and improved energy performance of the modern buildings. Homes with installed wall and loft insulation had much higher bedroom to living room ratio (76.9 %) than those without energy efficiency measures (52.6%).

PMID:34624870 | DOI:10.1088/1361-6498/ac2e0a

Biomed Phys Eng Express. 2021 Oct 8. doi: 10.1088/2057-1976/ac2e16. Online ahead of print.

ABSTRACT

In the medical field, automated and computerised analytic tools are essential for faster disease diagnosis. The main objective of this research work is to classify the leukocytes accurately into four different subtypes based on the pattern of the nucleus. The features are extracted from the segmented nucleus, which play a vital role in the pattern recognition. The technique comprises a novel idea of computing the statistical measures such as peak difference and standard deviation of the radon transformed graph for a single angle of rotation along with other features. Three Gray Level Co-occurrence Matrix (GLCM) based features, two geometric features and four RST moment invariants are also extracted for feature fusion. The fused feature vectors are trained and evaluated using random forest classification algorithm.This method provides an overall accuracy of 97.61% and it is able to determine the lymphocyte, neutrophil and eosinophil with 100% accuracy. The classification without incorporating radon transform features is also performed which provides an accuracy of only 80.95% .

PMID:34624876 | DOI:10.1088/2057-1976/ac2e16

J Neurosurg Pediatr. 2021 Oct 8:1-8. doi: 10.3171/2021.7.PEDS21263. Online ahead of print.

ABSTRACT

OBJECTIVE: Malignant peripheral nerve sheath tumors (MPNSTs) are rare tumors found throughout the body, with their clinical course in children still not completely understood. Correspondingly, this study aimed to determine survival outcomes and specific clinical predictors of survival in this population from a large national database.

METHODS: All patients with MPNSTs aged ≤ 18 years in the US National Cancer Database (NCDB) between 2005 and 2016 were retrospectively reviewed. Data were summarized, and overall survival was modeled using Kaplan-Meier and Cox regression analyses.

RESULTS: A total of 251 pediatric patients with MPNSTs (132 [53%] females and 119 [47%] males) were identified; the mean age at diagnosis was 13.1 years (range 1-18 years). There were 84 (33%) MPNSTs located in the extremities, 127 (51%) were smaller than 1 cm, and 22 (9%) had metastasis at the time of diagnosis. In terms of treatment, surgery was pursued in 187 patients (74%), chemotherapy in 116 patients (46%), and radiation therapy in 129 patients (61%). The 5-year overall survival rate was estimated at 52% (95% CI 45%-59%), with a median survival of 64 months (range 36-136 months). Multivariate regression revealed that older age (HR 1.10, p < 0.01), metastases at the time of diagnosis (HR 2.14, p = 0.01), and undergoing biopsy only (HR 2.98, p < 0.01) significantly and independently predicted a shorter overall survival. Chemotherapy and radiation therapy were not statistically significant.

CONCLUSIONS: In this study, the authors found that older patient age, tumor metastases at the time of diagnosis, and undergoing only biopsy significantly and independently predicted poorer outcomes. Only approximately half of patients survived to 5 years. These results have shown a clear survival benefit in pursuing maximal safe resection in pediatric patients with MPNSTs. As such, judicious workup with meticulous resection by an expert team should be considered the standard of care for these tumors in children.

PMID:34624851 | DOI:10.3171/2021.7.PEDS21263

J Neurosurg. 2021 Oct 8:1-10. doi: 10.3171/2021.4.JNS204013. Online ahead of print.

ABSTRACT

OBJECTIVE: The objective of this study was to compare complications, seizures, and neuropsychological outcomes after resective epilepsy surgery in patients ≥ 60 years of age who underwent operations to younger and matched controls.

METHODS: Charts of 2243 patients were screened for operated patients in the authors’ center between 2000 and 2015. Patients with available postsurgical follow-up data who were operated on at the age of 60 years or older and matched (by gender, histopathology, and side of surgery) controls who were between 20 and 40 years of age at the time of surgery were included. Outcomes regarding postoperative seizure control were scored according to the Engel classification and group comparisons were performed by using chi-square statistics.

RESULTS: Data of 20 older patients were compared to those of 60 younger controls. Postoperative seizure control was favorable in the majority of the elderly patients (Engel classes I and II: 75% at 12 months, 65% at last follow-up), but the proportion of patients with favorable outcome tended to be larger in the control group (Engel classes I and II: 90% at 12 months, p = 0.092; 87% at last follow-up, p = 0.032, chi-square test). The surgical complication rate was higher in the elderly population (65% vs 27%, p = 0.002), but relevant persistent deficits occurred in 2 patients of each group only. Neuropsychological and behavioral assessments displayed considerable preoperative impairment and additional postoperative worsening, particularly of verbal skills, memory (p < 0.05), and mood in the elderly.

CONCLUSIONS: The overall favorable postsurgical outcome regarding seizure control and the moderate risk of disabling persistent neurological deficits in elderly patients supports the view that advanced age should not be a barrier per se for resective epilepsy surgery and underscores the importance of an adequate presurgical evaluation and of referral of elderly patients to presurgical assessment.

PMID:34624859 | DOI:10.3171/2021.4.JNS204013

J Colloid Interface Sci. 2021 Sep 29;608(Pt 1):1-12. doi: 10.1016/j.jcis.2021.09.165. Online ahead of print.

ABSTRACT

Access to detailed information on cells loaded with nanoparticles with nanoscale precision is of a long-standing interest in many areas of nanomedicine. In this context, designing a single experiment able to provide statistical mean data from a large number of living unsectioned cells concerning information on the nanoparticle size and aggregation inside cell endosomes and accurate nanoparticle cell up-take is of paramount importance. Small-angle X-ray scattering (SAXS) is presented here as a tool to achieve such relevant data. Experiments were carried out in cultures of B16F0 murine melanoma and A549 human lung adenocarcinoma cell lines loaded with various iron oxide nanostructures displaying distinctive structural characteristics. Five systems of water-dispersible magnetic nanoparticles (MNP) of different size, polydispersity and morphology were analyzed, namely, nearly monodisperse MNP with 11 and 13 nm mean size coated with meso-2,3-dimercaptosuccinic acid, more polydisperse 6 nm colloids coated with citric acid and two nanoflowers (NF) systems of 24 and 27 nm in size resulting from the aggregation of 8 nm MNP. Up-take was determined for each system using B16F0 cells. Here we show that SAXS pattern provides high resolution information on nanoparticles disposition inside endosomes of the cytoplasm through the structure factor analysis, on nanoparticles size and dispersity after their incorporation by the cell and on up-take quantification from the extrapolation of the intensity in absolute scale to null scattering vector. We also report on the cell culture preparation to reach sensitivity for the observation of MNP inside cell endosomes using high brightness SAXS synchrotron source. Our results show that SAXS can become a valuable tool for analyzing MNP in cells and tissues.

PMID:34624760 | DOI:10.1016/j.jcis.2021.09.165

J Neurosurg Spine. 2021 Oct 8:1-11. doi: 10.3171/2021.5.SPINE21119. Online ahead of print.

ABSTRACT

OBJECTIVE: Available data on management of sacral arteriovenous fistulas (sAVFs) are limited to individual case reports and small series. Management includes observation, endovascular embolization, or surgical ligation, with no clear guidelines on the optimal treatment modality. The authors’ objective was to report their multiinstitutional experience with management of sAVF patients, including clinical and radiographic characteristics and postprocedural outcomes.

METHODS: The electronic medical records of patients with a diagnosis of spinal arteriovenous fistula treated from January 2004 to December 2019 at the authors’ institutions were reviewed, and data were summarized using descriptive statistics, including percentage and count for categorical data, median as a measure of central tendency for continuous variables, and interquartile range (IQR) as a measure of dispersion.

RESULTS: A total of 26 patients with sAVFs were included. The median (IQR) age was 65 (57-73) years, and 73% (n = 19) of patients were male. Lower-extremity weakness was the most common presenting symptom (n = 24 [92%]), and half the patients (n = 13 [50%]) reported bowel and bladder sphincter dysfunction. The median (IQR) time from symptom onset to treatment was 12 (5.25-26.25) months. Radiographically, all patients had T2 hyperintensity at the level of the conus medullaris (CM) (n = 26 [100%]). Intradural flow voids were identified in 85% (n = 22) of patients. The majority of the lesions had a single identifiable arterial feeder (n = 19 [73%]). The fistula was located most commonly at the S1 level (n = 13 [50%]). The site where the draining vein connects to the pial venous plexus was seen predominantly at the lumbar level (n = 16 [62%]). In total, 29 procedures were performed: 10 open surgeries and 19 endovascular embolization procedures. Complete occlusion was achieved in 90% (n = 9) of patients after open surgery and 79% (n = 15) after endovascular embolization. Motor improvement was seen in 68% of patients (n = 15), and bladder and bowel function improved in 9 patients (41%). At last follow-up, 73% (n = 16) of patients had either resolution or improvement of the pretreatment intramedullary T2 signal hyperintensity.

CONCLUSIONS: T2 hyperintensity of the CM and a dilated filum terminale vein are consistent radiographic signs of sAVF, and delayed presentation is common. Complete occlusion was achieved in almost all patients after surgery, and endovascular embolization was effective in 70% of the patients. Further studies are needed to determine the best treatment modality based on case-specific characteristics.

PMID:34624835 | DOI:10.3171/2021.5.SPINE21119

Water Res. 2021 Sep 30;206:117721. doi: 10.1016/j.watres.2021.117721. Online ahead of print.

ABSTRACT

Although the photochemical behavior of surface water and its effects on pollutant transformation have been studied extensively in recent years, the photochemistry of paddy water remains largely unknown. In this study, we examined the photochemical processes involving paddy water samples collected at four different cultivation stages of rice. Triplet dissolved organic matter (³DOM*), singlet oxygen (¹O₂), and hydroxyl radicals (^•OH) were found to be the dominant reactive intermediates (RIs), and their apparent quantum yields and steady-state concentrations were quantified. Compared with the typical surface water, quantum yields of ³DOM* and ^•OH were comparable, while quantum yields of ¹O₂ were about 2.4-6.7 times higher than those of surface water. Fluorescence emission-excitation matrix (EEM) spectra, Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS), and statistical analysis revealed that DOM properties and nitrite concentration were the main factor influencing RIs generation. The results suggest that DOM with lower molecular weight and humification extent generated more RIs, and nitrite contributed to 23.9%-100% of ^•OH generation. EEM and FTICR-MS data showed that DOM with more saturated and less aromatic formulas could produce more ³DOM* under the irradiation, while the polyphenolic components of DOM inhibited the formation of RIs. Moreover, RIs significantly enhanced arsenite (As(III)) oxidation with oxidation rate increased by 1.8-4.1 times in paddy water, and ^•OH and ³DOM* were the main RIs responsible for As(III) oxidation. This study provides new insight into the pathways of arsenite abiotic transformation in paddy soil and water.

PMID:34624658 | DOI:10.1016/j.watres.2021.117721

Geriatr Nurs. 2021 Sep 20;42(6):1388-1396. doi: 10.1016/j.gerinurse.2021.09.005. Online ahead of print.

ABSTRACT

OBJECTIVE: Guided by the vulnerable population framework, the aim was to describe the risks and protective strategies for COVID-19 spread and infections in a Skilled Nursing Facility (SNF).

METHOD: We conducted a retrospective cohort (March 1st-August 31st, 2020) study. Data were collected from internal COVID-19 documents and resident electronic health records. Data were summarized and analyzed using descriptive statistics, relative risk calculations, and cases charted by week onset.

RESULTS: There were 325 residents who lived in and 296 staff who worked at the SNF during the study period. There was a total of 2 confirmed cases among residents and 4 confirmed cases among staff. Cases were isolated and all were living at their baseline health status at the end of the study.

CONCLUSION: Understanding the vulnerability to and protective strategies for COVID-19 within SNFs could strengthen resident care, resiliency among the SNF community, and improve health policies.

PMID:34624696 | DOI:10.1016/j.gerinurse.2021.09.005

Neuroimage Clin. 2021 Sep 21;32:102823. doi: 10.1016/j.nicl.2021.102823. Online ahead of print.

ABSTRACT

PURPOSE: Hearing loss (HL) is one of the most common age-related diseases. Here, we investigate the central auditory correlates of HL in people with normal cognition and mild cognitive impairment (MCI) and test their association with genetic markers with the aim of revealing pathogenic mechanisms.

METHODS: Brain glucose metabolism based on FDG-PET, self-reported HL status, and genetic data were obtained from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) cohort. FDG-PET data was analysed from 742 control subjects (non-HL with normal cognition or MCI) and 162 cases (HL with normal cognition or MCI) with age ranges of 72.2 ± 7.1 and 77.4 ± 6.4, respectively. Voxel-wise statistics of FDG uptake differences between cases and controls were computed using the generalised linear model in SPM12. An additional 1515 FDG-PET scans of 618 participants were analysed using linear mixed effect models to assess longitudinal HL effects. Furthermore, a quantitative trait genome-wide association study (GWAS) was conducted on the glucose uptake within regions of interest (ROIs), which were defined by the voxel-wise comparison, using genotyping data with 5,082,878 variants available for HL cases and HL controls (N = 817).

RESULTS: The HL group exhibited hypometabolism in the bilateral Heschl’s gyrus (k_left = 323; k_right = 151; T_left = 4.55; T_right = 4.14; peak P_uncorr < 0.001), the inferior colliculus (k = 219;T = 3.53; peak P_uncorr < 0.001) and cochlear nucleus (k = 18;T = 3.55; peak P_uncorr < 0.001) after age correction and using a cluster forming height threshold P < 0.005 (FWE-uncorrected). Moreover, in an age-matched subset, the cluster comprising the left Heschl’s gyrus survived the FWE-correction (k_left = 1903; T_left = 4.39; cluster P_FWE-corr = 0.001). The quantitative trait GWAS identified no genome-wide significant locus in the three HL ROIs. However, various loci were associated at the suggestive threshold (p < 1e-05).

CONCLUSION: Compared to the non-HL group, glucose metabolism in the HL group was lower in the auditory cortex, the inferior colliculus, and the cochlear nucleus although the effect sizes were small. The GWAS identified candidate genes that might influence FDG uptake in these regions. However, the specific biological pathway(s) underlying the role of these genes in FDG-hypometabolism in the auditory pathway requires further investigation.

PMID:34624637 | DOI:10.1016/j.nicl.2021.102823