Sonographic assessment of the normal limits of the spleen in healthy school children in South-East Nigeria

Background/Objective: Ultrasonogrphy is a good modality for the  detection of splenomegaly even when it is not clinically palpable. The objective of this study was to establish the normal values of splenic length in healthy school children in South.East, Nigeria and to correlate them with body indices.Materials and Methods: This is a cross.sectional prospective study of 1315 children (633 boys and 682 girls) between the ages of 5 and 17 years. The splenic length was measured between the most superiomedial and the most inferiolateral margins, at the level of the hilum. Only the spleens that had normal shape and echotexture were measured. The mean splenic length and the 5th and 95th percentiles were determined for each age. The length was correlated with the sex, age, weight (WT), height, body mass index (BMI) and body surface area (BSA) of the subjects. A regression model for prediction of spleen dimension from age and body habitus was computed.Results: There was a significant correlation between splenic length and age, P < 0.001. Males had statistically significant longer spleen length than females. The splenic length correlated best with BSA, followed by body WT and least with BMI.Conclusions: This study noted racial variation between the established Nigerian values and results from other countries of the world. For the first time, a baseline value for splenic size for the Nigerian Children of various ages has been established with a regression model for predicting the splenic sizes.Key words: Children, echotexture, Nigeria, sonography, spleen,  splenomegaly, ultrasonograph

Posttraumatic stress disorder diagnostic criteria and suicidal ideation in a South African Police sample

Objective: Exposure to traumatic events may precipitate suicidal ideation. Once an individual is diagnosed with PTSD, a suicide risk assessment often follows. This study explores how PTSD symptom criteria correlate with suicidal ideation in a sample of police officers. While the psychometric measures of PTSD often mirror the DSM-IV-TR criteria, focusing on exposure, symptom, and duration criteria, suicidal ideation measures often focus on concepts quite different from that. In this report the focus was on investigating how PTSD symptom criteria correlate with the suicidal ideation.Method: A group of South African police officers (N = 217) were assessed by means of the Posttraumatic Diagnostic Scale and a short version of the Adult Suicide Ideation Questionnaire. Linear and hierarchical regressions were used to determine which PTSD symptom criteria best predict suicidalideation.Results: Hyperarousal was the primary predictor of suicidal ideation (R2 [adjusted] = 0.249). Intrusive thoughts added only marginally to the model, contributing a further 2.5% to the declared variance. The contributions of the other two symptom types were negligible.Conclusion: In this study hyperarousal correlated significantly with suicidal ideation. It is suggested that practitioners be alert to these symptoms as possible indicators of suicidal ideation. Implications for suicide risk assessment and prevention measures are discussed.Keywords: Stress Disorders; Post-Traumatic; Suicidal ideation; Police; South Afric

Forecasting Player Behavioral Data and Simulating in-Game Events

Understanding player behavior is fundamental in game data science. Video games evolve as players interact with the game, so being able to foresee player experience would help to ensure a successful game development. In particular, game developers need to evaluate beforehand the impact of in-game events. Simulation optimization of these events is crucial to increase player engagement and maximize monetization. We present an experimental analysis of several methods to forecast game-related variables, with two main aims: to obtain accurate predictions of in-app purchases and playtime in an operational production environment, and to perform simulations of in-game events in order to maximize sales and playtime. Our ultimate purpose is to take a step towards the data-driven development of games. The results suggest that, even though the performance of traditional approaches such as ARIMA is still better, the outcomes of state-of-the-art techniques like deep learning are promising. Deep learning comes up as a well-suited general model that could be used to forecast a variety of time series with different dynamic behaviors

Oxygen Degradation in Mesoporous Al<inf>2</inf>O<inf>3</inf>/CH<inf>3</inf>NH<inf>3</inf>PbI<inf>3-</inf><inf>x</inf>Cl<inf>x</inf> Perovskite Solar Cells: Kinetics and Mechanisms

The rapid pace of development for hybrid perovskite photovoltaics has recently resulted in promising figures of merit being obtained with regard to device stability. Rather than relying upon expensive barrier materials, realizing market-competitive lifetimes is likely to require the development of intrinsically stable devices, and to this end accelerated aging tests can help identify degradation mechanisms that arise over the long term. Here, oxygen-induced degradation of archetypal perovskite solar cells under operation is observed, even in dry conditions. With prolonged aging, this process ultimately drives decomposition of the perovskite. It is deduced that this is related to charge build-up in the perovskite layer, and it is shown that by efficiently extracting charge this degradation can be mitigated. The results confirm the importance of high charge-extraction efficiency in maximizing the tolerance of perovskite solar cells to oxygen.This work was supported by SABIC and by the EPSRC, including by the Supergen Supersolar Consortium (EP/J017361/1) and the European Union Seventh Framework Program [FP7 2007-2003] under grant agreement 604032 of the MESO project. GE is supported by the EPSRC and Oxford Photovoltaics Ltd. through a Nanotechnology KTN CASE award. JW acknowledges the Swire Educational Trust for supporting his D.Phil. study at Oxford. We thank Sian Dutton (University of Cambridge) for access to XRD facilities and Felix Deschler (University of Cambridge) for helpful discussions.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/aenm.20160001

Use of fetal biometry in the assessment of gestational age in South East Nigeria: Femur length and biparietal diameter

Background: Fetal growth is influenced by many factors such as race, socioeconomic status, genetics, geographical location, maternal diseases, and number of babies. Consequent upon these, fetal growth charts may vary from one location to another even within the same geographical entity.Objective: This study was designed to establish the fetal growth chart in antenatal women who had ultrasound scanning at the University of Nigeria Teaching Hospital, Enugu, South East Nigeria.Patients and Methods: This is a descriptive analysis of fetal biometric measurement of antenatal women. Four hundred and seventy pregnant women were studied.Results: The nomogram for the femur length (FL) and biparietal diameter (BPD) for the different weeks of gestation (from 13th to the 40th week) were established. Correlation coefficients between gestational age and the various fetal parameters were also reported. Growth charts using both FL and BPD were plotted. A regression model for prediction of fetal age using the fetal biometry was also deduced for the studied population.Conclusion: The fetal parameters used in this study were consistently smaller than reported values from European studies up to the 34th week of gestation after which a catch‑up growth till the 40 weeks was observed. Fetal parameters observed in this study were larger than most of the reported Asian values.Keywords: Fetal biometry, gestational age, intrauterine growth curve, South East Nigeria, ultrasoun

Predictors of Employee Involvement in a Worksite Health Promotion Program

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67001/2/10.1177_109019819001700404.pd

Reach-scale bankfull channel types can exist independently of catchment hydrology

© 2020 John Wiley &amp; Sons, Ltd. Reach-scale morphological channel classifications are underpinned by the theory that each channel type is related to an assemblage of reach- and catchment-scale hydrologic, topographic, and sediment supply drivers. However, the relative importance of each driver on reach morphology is unclear, as is the possibility that different driver assemblages yield the same reach morphology. Reach-scale classifications have never needed to be predicated on hydrology, yet hydrology controls discharge and thus sediment transport capacity. The scientific question is: do two or more regions with quantifiable differences in hydrologic setting end up with different reach-scale channel types, or do channel types transcend hydrologic setting because hydrologic setting is not a dominant control at the reach scale? This study answered this question by isolating hydrologic metrics as potential dominant controls of channel type. Three steps were applied in a large test basin with diverse hydrologic settings (Sacramento River, California) to: (1) create a reach-scale channel classification based on local site surveys, (2) categorize sites by flood magnitude, dimensionless flood magnitude, and annual hydrologic regime type, and (3) statistically analyze two hydrogeomorphic linkages. Statistical tests assessed the spatial distribution of channel types and the dependence of channel type morphological attributes by hydrologic setting. Results yielded 10 channel types. Nearly all types existed across all hydrologic settings, which is perhaps a surprising development for hydrogeomorphology. Downstream hydraulic geometry relationships were statistically significant. In addition, cobble-dominated uniform streams showed a consistent inverse relationship between slope and dimensionless flood magnitude, an indication of dynamic equilibrium between transport capacity and sediment supply. However, most morphological attributes showed no sorting by hydrologic setting. This study suggests that median hydraulic geometry relations persist across basins and within channel types, but hydrologic influence on geomorphic variability is likely due to local influences rather than catchment-scale drivers. © 2020 John Wiley &amp; Sons, Ltd

Why does a metal-superconductor junction have a resistance?

This is a tutorial article based on a lecture delivered in June 1999 at the NATO Advanced Study Institute in Ankara. The phenomenon of Andreev reflection is introduced as the electronic analogue of optical phase-conjugation. In the optical problem, a disordered medium backed by a phase-conjugating mirror can become completely transparent. Yet, a disordered metal connected to a superconductor has the same resistance as in the normal state. The resolution of this paradox teaches us a fundamental difference between phase conjugation of light and electrons.Comment: 12 pages, 5 postscript figures [v2: all figures inline

The Architectural Design Rules of Solar Systems based on the New Perspective

On the basis of the Lunar Laser Ranging Data released by NASA on the Silver Jubilee Celebration of Man Landing on Moon on 21st July 1969-1994, theoretical formulation of Earth-Moon tidal interaction was carried out and Planetary Satellite Dynamics was established. It was found that this mathematical analysis could as well be applied to Star and Planets system and since every star could potentially contain an extra-solar system, hence we have a large ensemble of exoplanets to test our new perspective on the birth and evolution of solar systems. Till date 403 exoplanets have been discovered in 390 extra-solar systems. I have taken 12 single planet systems, 4 Brown Dwarf - Star systems and 2 Brown Dwarf pairs. Following architectural design rules are corroborated through this study of exoplanets. All planets are born at inner Clarke Orbit what we refer to as inner geo-synchronous orbit in case of Earth-Moon System. By any perturbative force such as cosmic particles or radiation pressure, the planet gets tipped long of aG1 or short of aG1. Here aG1 is inner Clarke Orbit. The exoplanet can either be launched on death spiral as CLOSE HOT JUPITERS or can be launched on an expanding spiral path as the planets in our Solar System are. It was also found that if the exo-planet are significant fraction of the host star then those exo-planets rapidly migrate from aG1 to aG2 and have very short Time Constant of Evolution as Brown Dwarfs have. This vindicates our basic premise that planets are always born at inner Clarke Orbit. This study vindicates the design rules which had been postulated at 35th COSPAR Scientific Assembly in 2004 at Paris, France, under the title ,New Perspective on the Birth & Evolution of Solar Systems.Comment: This paper has been reported to Earth,Moon and Planets Journal as MOON-S-09-0007