Variation In Rates Research Articles

Decoupling Intrinsic Metal Ion Reduction Rates from Structural Outcomes in Multimetallic Nanoparticles.

Simultaneously controlling both stoichiometry and atom arrangement during the synthesis of multimetallic nanoparticles is often challenging, especially when the desired metal precursors exhibit large differences in their intrinsic reduction kinetics. In such cases, traditional synthetic methods often lead to the formation of exclusively phase-segregated structures. In this study, we demonstrate that the relative reduction kinetics of the metal precursors can be manipulated independently of their intrinsic differences in reduction rates by modulating the instantaneous concentrations of the metal cation precursors. We achieve this control by adjusting the precursor addition rate, which decouples chemical ordering outcomes from differences in precursor reduction kinetics. To guide these experiments, we describe a quantitative model to determine how metal ion reduction rates evolve with variations in the precursor addition rate and thereby predict optimal conditions for the synthesis of multimetallic nanoparticles with precise structural and compositional outcomes. We demonstrate the efficacy of this model experimentally by synthesizing both core@shell and alloyed nanoparticles with stoichiometric control using the same metal ion precursors in two different bimetallic systems (Au-Pd and Au-Pt) as well as in a quinary metal system (Co, Ni, Cu, Pd, and Pt). This approach enables the design of nanoparticle architectures independent of intrinsic differences in metal ion reduction potentials of the constituent metals while maintaining both stoichiometric and structural control.

Stochastic Modeling and Availability Optimization of Nuts Manufacturing Plant Using Markov Process and Particle Swarm Optimization

Availability is the key system effectiveness measure in process industries, manufacturing plants, and treatment plants like sewage, e-waste etc. The nut-bolt manufacturing industry is very prominent in manufacturing sector. The present work is proposed with a motto to develop a stochastic framework for a nut manufacturing plant to derive steady state availability and its optimization. The Markov birth death approach is applied to develop the stochastic model as well as Chapman-Kolmogorov differential difference equations of the system. The availability function derived using Markov approach is treated as objective function of the optimization problem having decision parameters as failure and repair rates. All the decision variables are considered as exponentially distributed which are i.i.d. in nature. The objective function is optimized using particle swarm optimization to predict the optimal availability and estimated parametric values. The most sensitive component of the system is observed through making variation in failure and repair rates. It is revealed that PSO predicts the optimal availability 0.9999 at population size 50 after 50 iterations. The convergence rate of PSO is very fast in prediction of the availability of nut manufacturing plant. These findings are beneficial for system designers and maintenance engineers to propose the maintenance strategies. The proposed methodology can be utilized to predict the availability of other process industries.

Persistent and severe hypotension during radical transabdominal ovarian cancer surgery: A case report.

In radical surgery for ovarian cancer (OC), hypotension that is difficult to correct is usually rare unless there is significant blood loss. We recently encountered a patient who developed persistent and severe hypotension during radical transabdominal OC surgery. A patient was 52 years old with a history of hypertension and well-controlled preoperative blood pressure (BP). A total of 2000 mL of ascites was drained and blood loss was 300 mL when the operation proceeded to 5.5 hours. The patient's cardiopulmonary function and blood gas analysis showed no significant abnormalities. persistent and uncorrectable hypotension. There was no significant edema in the patient's head or face, nor did the surgeon observe noticeable edema in her intestinal walls or other organs. No oozing was seen at the surgical site. Fluid resuscitation and vasopressor administration were continued. As BP control further deteriorated, blood counts, coagulation, and biochemical electrolyte analyses revealed severe hypoalbuminemia (13.5 g/L) and coagulation dysfunction. After intravenous human serum albumin (HSA) and fresh frozen plasma therapy, her hypoalbuminemia and coagulation were gradually corrected. Based on this case, we suggest that in OC patients experiencing mild intraoperative bleeding and minimal heart rate variation but persistent refractory hypotension, hypoalbuminemia should be considered even if preoperative biochemical tests (including serum albumin levels) are normal. Confirming hypoalbuminemia warrants HSA administration to alleviate hypovolemic shock symptoms. Additionally, it is important to be cautious of potential coagulation issues with albumin use, possibly requiring plasma infusion to address coagulopathy.

Research on reciprocating sealing performance and leakage rate prediction based on GA-PSO-BPNN hybrid algorithm

Purpose This study aims to investigate the sealing performance of reciprocating seals under the effect of rubber abrasion using ABAQUS simulation software, and to propose a prediction framework based on a hybrid algorithm (GA-PSO-BPNN) to predict the leakage of reciprocating seals of downhole gauging instrumentation under different working condition parameters. Design/methodology/approach The authors combined the UMESHMOTION user program with the improved Archard wear model to investigate reciprocating seal performance. GA and a PSO were proposed as ways to enhance the BPNN’s predictive model. Findings The results show that the impact of fluid pressure fluctuations on the wear of the seal lip is more pronounced during the rapid wear phase compared to the steady wear phase. Similarly, variations in compression rate have a greater impact on seal lip wear at different stages of wear. The GA-PSO-BPNN prediction model outperforms the single-prediction model in terms of prediction accuracy. Originality/value The authors investigated sealing performance through simulation software and propose a GA-PSO-BPNN-based fault diagnosis method for rotating machinery. To verify the accuracy of the prediction model, a reciprocating sealing test platform for gauge work cylinders is constructed. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2024-0293/

Testing the Feasibility of a Cross-Setting Measure to Address the Rising Trend in Hospital Outpatient TJA Procedures.

Elective primary total hip and total knee arthroplasty (collectively, total joint arthroplasties [TJAs]) are commonly performed procedures that can reduce pain and improve function. TJAs are generally safe, but complications can occur. Although historically performed as inpatient procedures, TJAs are increasingly being performed in the outpatient setting. We sought to develop a scientifically acceptable cross-setting measure for evaluating care quality across inpatient and outpatient settings. Using Medicare administrative claims and enrollment data for qualifying TJA patients, we respecified the Centers for Medicare & Medicaid Services (CMS) inpatient-only risk-standardized TJA complications measure to assess complication rates following elective primary TJAs performed in an inpatient or outpatient setting. We aligned inpatient and outpatient coding practices and used hierarchical logistic regression to calculate hospital-specific, risk-standardized complication rates (RSCRs). Lower rates correspond to better quality. Using accepted approaches for CMS measures, we tested measure reliability and vetted key measure decisions with patient and provider input. A single combined model including the procedure setting as a risk variable produced the highest discrimination (C-statistic for a single combined model with a setting indicator: 0.664, C-statistic for the inpatient-only model: 0.651, C-statistic for the outpatient-only model: 0.638). Among the 2,747 hospitals with at least 25 TJAs, the mean RSCR (using the combined model with a setting indicator) was 2.91% (median RSCR: 2.85%; interquartile range: 2.59% to 3.18%). The median odds ratio for complication occurrence at a higher-risk hospital compared with a lower-risk hospital was 1.33. We respecified a measure to assess hospital inpatient or outpatient TJA performance and evaluated the reliability and validity of the measure. The findings showed variation in hospital-level complication rates across settings as indicated by this measure, supporting the feasibility of evaluating hospital performance using a more representative population than inpatient TJAs alone. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Simulation study of the impacts of E-region density on the growth of equatorial plasma bubbles

Equatorial plasma bubbles (EPBs) in the ionospheric F region are notorious for causing severe scintillation in radio signals, posing significant challenges for communication and navigation systems. Understanding and forecasting EPB occurrence is crucial from a space weather perspective, given their impact on satellite and terrestrial communication. In this study, we present the impacts of E-region conductivity on the generation of EPBs by using the 3D high-resolution bubble (HIRB) model. By changing the production rate of NO+ ions in the E region, the flux-tube-integrated linear growth rate of the Rayleigh–Taylor instability can be modified. Multiple simulation runs show that even a moderate variation of the growth rate turns into a significant difference in EPB growth into the top of the ionosphere. This is a major factor that has made forecasting EPB generation quite difficult for several decades.

Holocene evolution of the buried tidal sand body in the North Jiangsu Plain of China revealed by luminescence dating

In the northern Jiangsu coastal zone of China, the buried tidal sand body (BTSB) is suggested to share a similar origin with the offshore radial sand ridge system in the southwestern Yellow Sea. However, its chronological framework remains inadequately understood. This study conducted optically stimulated luminescence (OSL) dating of both silt- and sand-sized quartz on core LDC from the southwestern end of the BTSB. Together with data from the previously studied core XYK closer to the current coastline, this study aims to clarify the chronology of the BTSB and refine its evolution history. The results indicate that in both cores, sand-sized quartz provides more reliable age estimates than silt-sized quartz for the sandy sediment layers. Additionally, the discrepancy between ages derived from the single-grain central age model and the minimum age model is smaller within the top 11 m of the core, which was deposited over the last 0.9 ka. This period corresponds well with the southern migration of the Yellow River and its sediment discharge into the Yellow Sea from 1128 to 1855 CE. It suggests that distinct sediment sources from the Yellow and Yangtze Rivers may account for the observed differences in OSL characteristics. The OSL ages reveal significant temporal variations in sedimentation rates during the Holocene, with the most rapid deposition occurring between 1.2–0.4 ka and 10–8 ka in core LDC, and between 2–1 ka in core XYK. Together with dating results from the central part of the BTSB, it reveals complex spatiotemporal variations in sediment accumulation and emphasizes the need for detailed sediment sampling and dating to fully elucidate the evolutionary history of the coastal plain.

An entropy analysis model and irreversibility assessment of solid oxide fuel cells based on the Gibbs relation of charged particles

Energy conversion is the main purpose of various fuel cells, but the irreversibility of thermodynamic processes – including electrochemical reactions and heat and mass transfer in fuel cells – lead to a decrease in energy efficiency. In this paper, we develop a systemic theoretical model to evaluate the irreversibility of solid oxide fuel cells (SOFCs). By combining the conservation equations for energy, mass, and momentum with the Gibbs relation for charged particles, we establish the energy-balance equation for SOFCs and derive the entropy generation rates (EGRs) associated with electrochemical reactions and charged particle transfer processes. We solve the coupling multiphysics model in a three-dimensional computational unit of a SOFC, and calculate the EGRs and entropy flux rate based on the proposed thermodynamic model and the numerical results. We analyse the conversion and transfer mechanisms of energy based on the distributions of different local EGRs and the entropy flux rate, and the influence of various thermodynamic processes, such as mass transfer, heat transfer, and flow, on the overall operation of SOFCs. The results show that the EGR due to electrochemical reactions in the SOFC is the largest and is mainly due to activation and concentration polarisation. Complex heat and mass transfer processes occur in the corner region formed at the intersection of the channel, the current junction, and the electrode, leading to a higher localised EGR. We also evaluate the effects of variations in the anode gas mass flow rate, the oxygen fraction, and the channel length on thermodynamic efficiency. This study contributes to the understanding of the complex mechanisms of irreversible losses in SOFCs and provides guidance for further improving the thermodynamic efficiency of SOFCs.

State-wise variation and inequalities in caesarean delivery rates in India: analysis of the National Family Health Survey-5 (2019–2021) data

State-wise variation and inequalities in caesarean delivery rates in India: analysis of the National Family Health Survey-5 (2019–2021) data

Practice of Electroconvulsive Therapy in Catalonia in 2022: Results From a Large Cross-Sectional Survey.

The practice of electroconvulsive therapy (ECT) exhibits variability across various domains, both between regions, and between centers within the same region. The ECT Working Group of the Catalan Society of Psychiatry conducted a comprehensive survey in Catalonia, Spain, to assess the current status of those variables essential in the clinical practice of ECT. The survey comprised 50 items, including various question types such as multiple-choice, numerical response, and open-ended questions. It was administered to the 20 public hospitals that currently provide ECT in Catalonia during the year 2022. Information was gathered on 4 main areas: Organization of the ECT Unit, Specific Technique of ECT Application, Strategies and Organization of the Therapeutic Plan, and Epidemiological Data, Training, and Healthcare Resource Management. Some notable findings include an application rate of 1.1 per 10,000 inhabitants, major depression diagnosis as the primary indication for ECT in 80% of the centers, and the ability to perform maintenance ECT in 100% of centers. Following the survey and analysis, 3 main findings emerged: minimal variation in ECT application rates compared to the previous decade, increased complexity in current ECT practices with a focus on quality and patient safety, and identified areas for improvement in resource management and the necessity for a well-trained and stable multidisciplinary team.

The geographical distribution of the family-genetic risk score for drug use disorder in Sweden and its co-localization with areas of social deprivation

Abstract Background Drug use Disorder (DUD), the risk for which is substantially influenced by both genetic and social factors, is geographically concentrated in high-risk regions. An important step toward understanding this pattern is to examine geographical distributions of the genetic liability to DUD and a key demographic risk factor – social deprivation. Methods We calculated the mean family genetic risk score (FGRS) for DUD ((FGRSDUD) and social deprivation for each of the 5983 areas Demographic Statistical Areas (DeSO) for all of Sweden and used geospatial techniques to analyze and map these factors. Results Using 2018 data, substantial spatial heterogeneity was seen in the distribution of the genetic risk for DUD in Sweden as a whole and in its three major urban centers which was confirmed by hot-spot analyses. Across DeSOs, FGRSDUD and s.d. levels were substantially but imperfectly correlated (r = + 0.63), with more scattering at higher FGRSDUD and s.d. scores. Joint mapping across DeSOs for FGRSDUD and s.d. revealed a diversity of patterns across Sweden. The stability of the distributions of FGRSDUD and s.d. in DeSOs within Sweden over the years 2012–2018 was quite high. Conclusions The geographical distribution of the genetic risk to DUD is quite variable in Sweden. DeSO levels of s.d. and FRGSDUD were substantially correlated but also disassociated in a number of regions. The observed patterns were largely consistent with known trends in the human geography of Sweden. This effort lays the groundwork for further studies of the sources of geographic variation in rates of DUD.

The paradox of predictability provides a bridge between micro- and macroevolution.

The relationship between the evolutionary dynamics observed in contemporary populations (microevolution) and evolution on timescales of millions of years (macroevolution) has been a topic of considerable debate. Historically, this debate centers on inconsistencies between microevolutionary processes and macroevolutionary patterns. Here, we characterize a striking exception: emerging evidence indicates that standing variation in contemporary populations and macroevolutionary rates of phenotypic divergence is often positively correlated. This apparent consistency between micro- and macroevolution is paradoxical because it contradicts our previous understanding of phenotypic evolution and is so far unexplained. Here, we explore the prospects for bridging evolutionary timescales through an examination of this "paradox of predictability." We begin by explaining why the divergence-variance correlation is a paradox, followed by data analysis to show that the correlation is a general phenomenon across a broad range of temporal scales, from a few generations to tens of millions of years. Then we review complementary approaches from quantitative genetics, comparative morphology, evo-devo, and paleontology to argue that they can help to address the paradox from the shared vantage point of recent work on evolvability. In conclusion, we recommend a methodological orientation that combines different kinds of short-term and long-term data using multiple analytical frameworks in an interdisciplinary research program. Such a program will increase our general understanding of how evolution works within and across timescales.

A nationwide snapshot study on outcomes one year after surgery for chronic pilonidal sinus disease.

Managing pilonidal sinus disease (PSD) remains challenging due to high recurrence rates and morbidity associated with treatment. The aim of this study was to evaluate the outcomes one year after surgical treatment for chronic PSD in the Netherlands. Patients with PSD who underwent surgical treatment between March 1, 2020, and March 1, 2021, at 36 participating hospitals were included in a prospective observational cohort study. For the present study, only patients with chronic PSD were included for analysis. One-year after surgical treatment for PSD, all patients received questionnaires on wound healing, quality of life (QoL), and patient reported experience measures (PREMs). Primary outcome was recurrence rate. Secondary outcomes included QoL and PREMs. Of 681 included patients, 405 patients presented with chronic PSD and underwent surgical treatment. One-year questionnaires were completed by 289 out of 405 patients (71.4%). Patients underwent either excision with secondary wound healing (ESW, n = 73), excision with midline closure (EMC, n = 21), off-midline closure (OMC, n = 17), or a minimally invasive technique (MIT, n = 178). Patient-reported recurrence rates after ESW, EMC, OMC and MIT were 21.5%, 25%, 6.7% and 30.6%, respectively. Pain/discomfort and anxiety/depression were the most frequently reported problems affecting QoL. Patients that underwent OMC were satisfied the most with the care provided. This study demonstrates variation in recurrence rates among surgical procedures for PSD. The highest rates were observed in the MIT and EMC group, while the OMC group exhibited the lowest rate. QoL outcomes differed among the surgical techniques. Patient satisfaction appears highest in the OMC group.

Comprehensive analysis of mode-I cracking in ice: Exploring full-range rate dependency

Ice, as a crystalline material, demonstrates a unique response in its mode-I fracture toughness to variations in loading rates, characterized by an initial decrease and subsequent increase in toughness. This phenomenon has been explored in limited studies. In this work, an extensive numerical analysis of mode-I ice cracking is conducted by using the distinct lattice spring model (DLSM). Norton-Bailey Drucker-Prager DLSM (NB-DP-DLSM) is initially employed to investigate the classical explanations of creep and stress relaxation for the anomaly observed in ice’s fracture toughness at lower loading rates, but this approach does not successfully replicate the experimentally observed strain rate dependency. Then, two rate-dependent constitutive models are introduced to further examine the mode-I fracture mechanics of ice. Our numerical simulations of three-point bending tests show that the relationship between fracture toughness and strain rate at lower levels is more accurately captured by rate-dependent models. For higher strain rates, our numerical modeling of notched semi-circular bending tests indicates that a rate-independent constitutive model can replicate the loading rate dependency of ice’s mode-I fracture toughness. In conclusion, these observations suggest that a reverse-stage-like dynamic constitutive model for DLSM can potentially capture the full range of loading rate dependencies observed in ice.

Use of Pulmonary Rehabilitation after Chronic Obstructive Pulmonary Disease Hospitalization: An Analysis of Statewide Patient and Hospital Data.

Rationale: Pulmonary rehabilitation (PR) is a clinically effective and cost-effective outpatient treatment for chronic obstructive pulmonary disease (COPD) that remains highly underused. Existing analyses of PR use patterns have been focused largely on patient characteristics, but hospital-level analysis is lacking and is needed to inform interventions aimed at improving use after COPD hospitalization. Objectives: To evaluate PR use across hospitals after COPD hospitalization in the state of Michigan, with the goal of characterizing hospital-level variation and identifying the characteristics of high-performing hospitals. Methods: This is a retrospective study of patients with COPD hospitalizations between January 1, 2018, and December 31, 2021, using claims data from the Michigan Value Collaborative and hospital data from the American Hospital Association annual survey. Our primary outcome was the initiation of PR within 30 days of discharge. Chi-square tests and analysis of variance were used to test for differences in patient and hospital covariates. Multilevel logistic regression was used to analyze associations between patient covariates and the primary outcome and to characterize hospital-level variation. Results: A total of 36,389 patients and 99 hospitals were included in the analysis. The majority of patients were older than 65 years of age, female, White, and Medicare fee-for-service insured. The rate of PR initiation within 30 days after hospitalization was 0.8%. Adjusted rates of PR initiation by hospital ranged from 0.4% to 2.0%. Compared with the set reference groups, being female, in the fifth Distressed Community Index quintile, and older than 85 years of age independently decreased the odds of initiating PR. Some variation in initiation rate was attributed to the hospital level (7%; intraclass correlation coefficient = 0.07 [95% confidence interval, 0.03-0.15]). The median odds ratio was 1.6 for PR initiation by hospital. Conclusions: Rates of PR initiation after COPD hospitalization are universally low across all hospitals, though there is some variation. Interventions targeted at patients alone are not sufficient to improve use. Hospital-based strategies to improve PR use after discharge, adapted from those being successfully used with cardiac rehabilitation, should be further explored.

Study Evapotranspiration in Iraq Using the Penniman-Monteith Equation for the Period (2008-2020)

Evapotranspiration is considered an essential element for the stability of the ecosystem due to its importance in many aspects, including the water cycle, which is an important source of fresh water for humans, animals and plants. It also influences climate and temperatures and regulates weather. It also enters into the design of crop irrigation networks, knowing their water needs to prevent drought and desertification. The Penman-Monteith method is effective and accurate for calculating daily reference evapotranspiration and has been adopted by the Food and Agriculture Organization (FAO) as a standard method. This study aims to calculate the variation in evapotranspiration rates in Iraq using the Penman-Monteith method over the past thirteen years (2008-2020) in five equal periods (2008, 2011, 2014, 2017, and 2022). This study showed that the total rates of evapotranspiration are decreasing, and these values ​​peaked in 2008 and then decreased significantly in subsequent years. The reason for this decrease is the decrease in wind speed and the increase in relative humidity. It was found that evapotranspiration rates in the central and southern governorates are higher than in the northern governorates. However, there are deviations in the rates for some stations, such as in 2020, which witnessed a general decrease in evapotranspiration rates, except for some stations that recorded an increase. For example, Khanaqin station recorded the highest increase in evapotranspiration rates, which amounted to 23.6%. The reason for this increase is the increase in temperatures by 5.2% and the decrease in relative humidity by -6.5%.

Intrinsic versus extrinsic contribution to intraindividual sweat rate variability of individual eccrine glands

The purpose of the current study was twofold. First, to determine the intraindividual variability of sweat rate per gland for a given skin location during exercise in the heat. Second, to determine the relative importance of intrinsic vs. extrinsic factors as the source of the intraindividual variability in sweat rate per gland. Sweat rate of individual eccrine glands on the forearm was measured following pilocarpine iontophoresis and during exercise in the heat. In five participants during exercise in the heat the measured sweat rate for individual forearm eccrine glands (n = 500) ranged from 0.5 nL/gland/min to 16 nL/gland/min, or over a 30-fold difference. The mean (SD) intraindividual coefficient of variation in sweat rate per gland was 36 (5)% and 49 (10)% (p = 0.008) following pilocarpine iontophoresis and during exercise in the heat, respectively. Such results suggest that intrinsic factors (i.e., sweat gland size and cholinergic sensitivity) contribute approximately three times more than extrinsic factors (i.e., sweat gland nerve fiber density and threshold amplitude) towards explaining the large intra-person variability in sweat rate per gland seen during exercise in the heat.

Assessment of cutting force coefficient identification methods and force models for variable pitch and helix bull-nose tools

The mechanistic approach is commonly implemented to predict and optimise the cutting forces in milling processes to prevent tool breakages, reduce tool wear, reduce form error, and improve surface quality. To implement this method, the cutting force coefficients (CFCs), that characterise the mechanics of the process, must be calculated. This study compares the accuracy of the predicted cutting forces for variable pitch and helix bull-nose milling tools using a rapid testing (RT) optimisation-based mechanistic CFC identification method that only requires a single angular cut with increasing radial engagement to the traditional mechanistic approach that requires several straight cuts. Along with developing a hybrid technique that combines variation in feed rate and radial engagement. The traditional radial, tangential, and axial (RTA) force model is also compared with the frictional and normal rake face (UV) force model that is independent of the local tool rake and inclination angles which is a necessary for bull nose tools. The RT and the developed hybrid CFC identification method with the UV force model predicted the average Fx, Fy and Fz cutting forces to within 7.1 %, 4.3 %, and 3.8 % error, respectively. These methods were slightly less accurate than the traditional method, however they have significant industrial benefits because they have can be used to identify CFCs with either a single cut, or from any tool-path with chip-load variation, respectively. The RTA force model predicted the average cutting forces similarly to the UV force model, however, the UV force model had lower errors using the rapid RT testing method at the extreme corners of the experimental design space.

Contribution of Organic Carbon, Moisture Content, Microbial Biomass-Carbon, and Basal Soil Respiration Affecting Microbial Population in Chronosequence Manganese Mine Spoil

The research was carried out to determine the potential effect of microbiota, organic carbon, percentage of moisture content, and microbial biomass concentration as an evaluator of variation in basal soil respiration rate. Relative distribution and composition of the microbial population were estimated from six different chronosequence manganese mine spoil (MBO0, MBO2, MBO4, MBO6, MBO8, MBO10) and forest soil (FS). The variation was seen in moisture content (6.494±0.210-11.535±0.072)%, organic carbon (0.126±0.001- 3.469± 0.099)%, MB-C (5.519±1.371- 646.969± 11.428) μg.g-1 of soil. A positive correlation was shown between OC with MB-C (r = 0.938; p< 0.01) and moisture content (MC) (r = 0.962; p< 0.01). Variation in the basal soil respiration (BSR) and microbial metabolic quotients (MMQ) was shown to range between 0.352 ± 0.007- 0.958 ±0.014μg CO2-C.g-1 and 6.5× 10-3 - 1.481×10-3 μg CO2-C.g-1 microbial-C.h-1 with BSR: OC from (2.793-0.276)% respectively. This result shows that there is a gradual increase in OC, MC, MB-C, and BSR across seven different sites due to progressive enhancement in soil fertility that leads to the initialization of succession. Stepwise multiple regression analysis further confirms the degree of variability added by microbial biomass C, moisture content, organic carbon, and microbial population on basal soil respiration in microbes. Principal component analysis enables the differentiation of seven different soil profiles into independent clusters based on cumulative variance given by physico-chemical and microbial attributes that indicate the level of degradation of land and act as an index to restore soil fertility.

Changes in short-term variation of antenatal cardiotocography to identify intraamniotic infection: a historical cohort study

Introduction Intraamniotic infection (IAI) is one of the main possible complications of preterm prelabor rupture of membranes (PPROM) and can lead to severe consequences for the neonate, such as early onset neonatal sepsis (EONS). Available diagnostic tools for IAI have poor diagnostic performance, which may result in both over- and underdiagnoses of IAI. In a search for better diagnostic tools, we have examined short-term variation (STV) in fetal heart rate. We have previously shown that in IAI exposed pregnancies, the STV was more than 20% lower in the last cardiotocography trace before the start of labor, as compared to those not exposed to IAI. The association between IAI and STV needs further evaluation and we therefore continued by examining the longitudinal change in STV in association with IAI. Material and methods We performed a historical cohort study on 628 singleton pregnancies with PPROM, delivering between 24 + 0 to 33 + 6 gestational weeks. The main exposure of the study was IAI, using EONS as a proxy as no easily available method exists for confirming IAI antepartum, and IAI and EONS are strongly associated. The main outcome was STV in fetal heart rate. At least two available cardiotocography traces per fetus were required as a minimum, from PPROM or from seven days before birth, whichever came later, until the start of labor or planned cesarean birth. A total of 9 690 cardiotocography traces were analyzed. Results Fetuses exposed to IAI had a 26.5% steeper decline in their STV during the last 24 h before the start of labor when compared to fetuses not exposed (95% CI −32.9% to −19.4%; p < 0.001). After adjustment for antenatal corticosteroids, the decline remained significant. The decline became less prominent but the significance remained when also adjusting for the baseline frequency (−12.7% [95% CI −19.3% to −5.5%], p < 0.001). In the IAI-exposed group, the baseline frequency increased by 11.1 bpm during the last 12 h before the start of labor, beyond those who were not exposed (95% CI 8.3 bpm to 13.8 bpm; p < 0.001). Conclusions In pregnancies affected by IAI the STV declines steeper in the last 24 h before the start of labor as compared to pregnancies not affected by IAI, even after adjustment for increasing baseline frequency. The association of STV in relation to IAI needs to be further studied in order to evaluate and establish STVs usefulness in monitoring patients for IAI.