Nevin Manimala

Environ Sci Pollut Res Int. 2021 Jun 7. doi: 10.1007/s11356-021-14732-6. Online ahead of print.

ABSTRACT

This paper investigates the dynamic short-term and long-term relationships among real GDP per capita, energy consumption, urbanization, and carbon dioxide emissions within the framework of the environmental Kuznets curve (EKC) hypothesis for Southeastern Europe (SEE) from 1997 to 2014. The evidence highlights an inverted U-shaped nexus between real GDP per capita and carbon dioxide emissions (i.e., the EKC hypothesis is verified in the long-run in the sample as a whole). The short-run estimates provide evidence of inverted U-shaped EKC only for Greece and Moldova. Two-way causal relationship between urbanization and pollutant emission was also established in the short-run, as well as one-way causality flowing from real GDP per capita to pollutant emission. The coefficients with the real GDP per capita and energy consumption are negative and statistically significant in the long-term. These findings indicate the existence of an error correction mechanism that drives the observed variables back to their equilibrium. Moreover, the findings show that the consistent increase in energy consumption has not reduced environmental pressures.

PMID:34097219 | DOI:10.1007/s11356-021-14732-6

Mol Biol Rep. 2021 Jun 7. doi: 10.1007/s11033-021-06470-2. Online ahead of print.

ABSTRACT

Genome-wide association studies have paved the way for the discovery of new markers regarding many diseases, including male infertility. A previous study on Caucasians highlighted 172 polymorphisms for their putative association with male infertility and we attempted to replicate these findings on our dataset comprising of Greek male individuals (n = 360). We retrieved 59 out of 172 polymorphisms and tested for all association models on 278 normospermic men and 82 patients with an abnormal seminogram, later separated into oligozoospermic and asthenozoospermic groups. Our findings indicate that two SNPs (rs2296225 in KIF17, rs7224496 in SMYD4) are associated with male infertility in the Greek population and have not been recorded in literature as of yet. These novel markers need further validation via additional studies and an increased individual number. All in all, replication studies, possess the power to validate existing polymorphisms found across all population and thus increase both statistical significance as well as identify novel potentially diagnostic markers.

PMID:34097203 | DOI:10.1007/s11033-021-06470-2

Psychometrika. 2021 Jun 7. doi: 10.1007/s11336-021-09771-4. Online ahead of print.

ABSTRACT

The model-implied instrumental variable (MIIV) estimator is an equation-by-equation estimator of structural equation models that is more robust to structural misspecifications than full information estimators. Previous studies have concentrated on endogenous variables that are all continuous (MIIV-2SLS) or all ordinal . We develop a unified MIIV approach that applies to a mixture of binary, ordinal, censored, or continuous endogenous observed variables. We include estimates of factor loadings, regression coefficients, variances, and covariances along with their asymptotic standard errors. In addition, we create new goodness of fit tests of the model and overidentification tests of single equations. Our simulation study shows that the proposed MIIV approach is more robust to structural misspecifications than diagonally weighted least squares (DWLS) and that both the goodness of fit model tests and the overidentification equations tests can detect structural misspecifications. We also find that the bias in asymptotic standard errors for the MIIV estimators of factor loadings and regression coefficients are often lower than the DWLS ones, though the differences are small in large samples. Our analysis shows that scaling indicators with low reliability can adversely affect the MIIV estimators. Also, using a small subset of MIIVs reduces small sample bias of coefficient estimates, but can lower the power of overidentification tests of equations.

PMID:34097200 | DOI:10.1007/s11336-021-09771-4

Gen Thorac Cardiovasc Surg. 2021 Jun 7. doi: 10.1007/s11748-021-01663-9. Online ahead of print.

ABSTRACT

OBJECTIVES: Controversy exists regarding the justification of primary surgery in primary spontaneous pneumothorax, and surgery is not free from recurrence. We hypothesized that surgery is a risk factor for contralateral recurrence pneumothorax in adolescent.

METHODS: We performed a retrospective cohort study of 163 adolescent with pneumothorax who were treated conservatively with chest tube (n = 100) or chest tube followed by video-assisted thoracoscopic surgery (n = 63) from January 2009 through December 2017.

RESULTS: Ipsilateral recurrence was significantly more common following conservative treatment than surgical treatment (25.0 vs. 3.2%, P < 0.001), while contralateral recurrence was more common in the surgical group than in the conservative group (15.9 vs. 6.0%, P = 0.039). The rates of second episode pneumothorax did not significantly differ between the two treatment groups (P = 0.092). Univariate analysis identified that patients who were treated conservatively had greater risk of ipsilateral recurrence (P = 0.002), while those who proceeded to surgery had greater risk of contralateral recurrence (P = 0.046). No predictors for second episode pneumothorax were found.

CONCLUSION: To avoid over treatment, we recommend that conservative treatment should be the superior option and CT scan should not be a routine examination in adolescent with their first episode of PSP.

PMID:34097199 | DOI:10.1007/s11748-021-01663-9

Hernia. 2021 Jun 7. doi: 10.1007/s10029-021-02431-7. Online ahead of print.

ABSTRACT

PURPOSE: Laparoscopic totally extraperitoneal hernia repair (TEP) is a widely used treatment for inguinal hernia. Single-incision laparoscopic TEP (SILTEP) has attracted the attention of several surgeons, given its superior cosmetic results and patient satisfaction, as well as comparable outcomes to multiport surgery. Nonetheless, no relevant studies have evaluated the learning curve (LC) of SILTEP in terms of both operation time (OT) and surgical failure. Therefore, we aimed to investigate the LC of SILTEP for inguinal hernia.

METHODS: Medical records of 180 patients who underwent SILTEP performed by a single surgeon from a single institution between October 2012 and November 2017 were retrospectively reviewed. The LC was analyzed using the moving average method and cumulative sum control chart (CUSUM) for OT and surgical failure. Surgical failure was defined as the need for additional ports, open conversion, severe postoperative complications (Clavien-Dindo ≥ IIIa), and recurrence. Eight patients who underwent combined surgery or bilateral hernia repair were excluded from the OT analysis.

RESULTS: From CUSUM graphs, the study period was divided into three phases: OT-phases 1 (1st-32nd), 2 (33rd-83rd), and 3 (84th-172nd) for OT and failure-phases 1 (1st-29th), 2 (30th-58th), and 3 (59th-180th) for surgical failure. Mean OTs were statistically different in the three OT phases (64.6 vs. 50.8 vs. 35.2 min; p < 0.001). Open conversion (31.0% vs. 0% vs. 2.5%) and additional port insertion (6.9% vs. 24.1% vs. 2.5%) stabilized consecutively at failure-phases 2 and 3 (p < 0.001). Surgical failure rates decreased to 5.7% by failure-phase 3 (37.9% vs. 24.1% vs. 5.7%; p < 0.001).

CONCLUSION: For an experienced laparoscopic surgeon, we estimated that approximately 60 cases are needed to overcome the LC for SILTEP in terms of both reducing OT and achieving a surgical failure rate < 10%. Further proficiency could be achieved after approximately 85 SILTEP procedures with a stable OT of approximately 35 min.

PMID:34097186 | DOI:10.1007/s10029-021-02431-7

J Occup Rehabil. 2021 Jun 7. doi: 10.1007/s10926-021-09988-1. Online ahead of print.

ABSTRACT

PURPOSE: Workers’ compensation claims consist of occupational injuries severe enough to meet a compensability threshold. Theoretically, systems with higher thresholds should have fewer claims but greater average severity. For research that relies on claims data, particularly cross-jurisdictional comparisons of compensation systems, this results in collider bias that can lead to spurious associations confounding analyses. In this study, I use real and simulated claims data to demonstrate collider bias and problems with methods used to account for it.

METHODS: Using Australian claims data, I used a linear regression to test the association between claim rate and mean disability durations across Statistical Areas. Analyses were repeated with nesting by state/territory to account for variations in compensability thresholds across compensation systems. Both analyses are repeated on left-censored data. Simulated claims data are analysed with Cox survival analyses to illustrate how left-censoring can reverse effects.

RESULTS: The claim rate within a Statistical Area was inversely associated with disability duration. However, this reversed when Statistical Areas were nested by state/territory. Left-censoring resulted in an attenuation of the unnested association to non-significance, while the nested association remained significantly positive. Cox regressions with simulated claims data demonstrated how left-censoring can reverse effects.

CONCLUSIONS: Collider bias can seriously confound work disability research, particularly cross-jurisdictional comparisons. Work disability researchers must grapple with this challenge by using appropriate study designs and analytical approaches, and considering how it affects the interpretation of results.

PMID:34097183 | DOI:10.1007/s10926-021-09988-1

Eur J Clin Microbiol Infect Dis. 2021 Jun 7. doi: 10.1007/s10096-021-04287-2. Online ahead of print.

ABSTRACT

Modifying enzyme-CrpP and its variants reduced the MICs of fluoroquinolones in Pseudomonas aeruginosa. This study investigated the dissemination and functional characteristics of CrpP-like in P. aeruginosa from China. The positive rate of crpP-like genes in 228 P. aeruginosa was 25.4% (58/228), and 6 new crpP-like genes were determined. Transformation experiments showed that CrpP-like had a low effect on CIP and LEV susceptibility. The genetic of crpP-positive was diverse. Furthermore, the mean expression level of crpP was no statistical difference between fluoroquinolone-susceptible and -resistant group (P > 0.05). CrpP-like may not play a significant role in fluoroquinolone resistance in P. aeruginosa.

PMID:34097170 | DOI:10.1007/s10096-021-04287-2

Eur J Orthop Surg Traumatol. 2021 Jun 7. doi: 10.1007/s00590-021-03017-w. Online ahead of print.

ABSTRACT

PURPOSE: Short-stem prostheses in hip arthroplasty have emerged as an alternative to conventional stems, especially in younger patients. The purpose of this study was to compare functional and radiological results of a short metaphyseal fitting cementless stem versus a conventional stem implant, in patients younger than 60 years.

METHODS: All patients operated from January 2006 to April 2013 were included, obtaining a minimum follow-up of 7 years. Harris Hip Score (HHS) and SF-36 (quality of life) questionnaires were applied and the presence of “thigh pain” was specifically assessed. We also compared complication rate, revision rate and average prosthesis survival. Femoral stress shielding (Gruen scale), stem subsidence, varus-valgus tilt and implant stability (Engh scale) were also compared.

RESULTS: A total of 101 short-stem and 74 conventional arthroplasties were included, with an average follow-up of 9.82 (7-14) years. HHS functional score and SF-36 were excellent in both implants and no significant difference between them (p > 0.05) was found. However, “thigh pain” was present in 7 patients with conventional stems and none with short-stems (p < 0.001). The survival rate at 13 years was 99%, for both implants, and no significant differences were found between them (χ²(2) = 0.178; p = 0.673). Conventional stems had stress shielding at the greater trochanter in 72% of the cases and 43% at the calcar, being statistically superior (p < 0.001) to the stress shielding observed in the short stems.

CONCLUSION: According to our results, this short-stem seems to allow preservation of bone stock, with decreased stress shielding and also a lower incidence of thigh pain compared to conventional stems.

LEVEL OF EVIDENCE: Level III retrospective comparative study.

PMID:34097153 | DOI:10.1007/s00590-021-03017-w

Carbon Balance Manag. 2021 Jun 7;16(1):19. doi: 10.1186/s13021-021-00182-7.

ABSTRACT

BACKGROUND: Legacy data are unique occasions for estimating soil organic carbon (SOC) concentration changes and spatial variability, but their use showed limitations due to the sampling schemes adopted and improvements may be needed in the analysis methodologies. When SOC changes is estimated with legacy data, the use of soil samples collected in different plots (i.e., non-paired data) may lead to biased results. In the present work, N = 302 georeferenced soil samples were selected from a regional (Sicily, south of Italy) soil database. An operational sampling approach was developed to spot SOC concentration changes from 1994 to 2017 in the same plots at the 0-30 cm soil depth and tested.

RESULTS: The measurements were conducted after computing the minimum number of samples needed to have a reliable estimate of SOC variation after 23 years. By applying an effect size based methodology, 30 out of 302 sites were resampled in 2017 to achieve a power of 80%, and an α = 0.05. A Wilcoxon test applied to the variation of SOC from 1994 to 2017 suggested that there was not a statistical difference in SOC concentration after 23 years (Z = – 0.556; 2-tailed asymptotic significance = 0.578). In particular, only 40% of resampled sites showed a higher SOC concentration than in 2017.

CONCLUSIONS: This finding contrasts with a previous SOC concentration increase that was found in 2008 (75.8% increase when estimated as differences of 2 models built with non-paired data), when compared to 1994 observed data (Z = – 9.119; 2-tailed asymptotic significance < 0.001). This suggests that the use of legacy data to estimate SOC concentration dynamics requires soil resampling in the same locations to overcome the stochastic model errors. Further experiment is needed to identify the percentage of the sites to resample in order to align two legacy datasets in the same area.

PMID:34097152 | DOI:10.1186/s13021-021-00182-7

Environ Monit Assess. 2021 Jun 7;193(7):389. doi: 10.1007/s10661-021-09186-9.

ABSTRACT

The present investigation has been carried out in the Ottapidaram taluk to evaluate the suitability of groundwater for drinking purposes and to assess the non-carcinogenic health risks. Twenty groundwater samples were collected, and the major physicochemical parameters were measured along with the heavy metals lead (Pb²⁺) and chromium (Cr²⁺). The analyzed anions and cations follow the average dominance order, Cl^– > PO₄^3- > SO₄^2- > NO₃^– > F^–, and Mg²⁺ > Ca²⁺ > Na⁺ > K⁺, respectively. From the water quality index to know the 45% of the water samples are unsuitable for drinking purposes. The statistical analysis of the data infers that major geochemical process of the region is leaching of salts by contaminated water, followed by industrial pollution and geogenic sources. The spatial representation of the different parameters reveals that the western part of the study area is predominated by geogenic sources and the eastern part is contaminated by industrial effluents. The non-carcinogenic risks of F^–, NO₃^–, Cr²⁺_, and Pb²⁺ were assessed. The findings show 40% of the samples exceeds the chromium hazard quotient, and 50% exceed the lead hazard quotient value of 1 recommended by the US Environmental Protection Agency (USEPA). The present investigation shows that Cr²⁺ and Pb²⁺ highly pollute the groundwater due to the industrial impacts. The present study suggests that the groundwater from this taluk is worse, and people from this taluk have health risks due to groundwater drinking.

PMID:34097151 | DOI:10.1007/s10661-021-09186-9