654 research outputs found
The relationship between violence during pregnancy and low birth weight: A meta-analysis study
Background & Aim: Violence during pregnancy affects both mother and fetus. This study was performed to investigate the relationship between physical, sexual and psychological violence during pregnancy and low birth weight in the world as a meta-analysis. Methods & Materials: This study is a meta-analysis that was performed on articles published in Persian and English languages from the beginning of 1995 to the end of 2015. Articles were extracted by searching in the databases of Scopus, Medline, EMBASE, Pubmed, Web of Science, Google scholar, Science Direct, Irandoc, Magiran, Medlib, and SID using key words of violence during pregnancy, low birth weight, physical, sexual and psychological violence and their compounds. The results of studies were combined using a random effects model in the meta-analysis. The heterogeneity of studies was evaluated using the I2 index and meta-regression, and the data analysis was performed using STATA software v.11.2 and SPSS software v.16. Results: Of 254 found articles, 16 relevant articles with the sample number of 117287 people were included in the study. The results of meta-analysis showed that physical OR:1.61 (CI95:2.04–2.28), psychological OR:1.26 (CI95:1.02–1.56) and sexual violence OR:1.26 (CI95:1.02–1.56) during pregnancy, lead to an increase in the rate of low birth weight infants in the exposed mothers. Conclusion: Physical, psychological and sexual violence during pregnancy lead to an increase in the rate of low birth weight infants in the exposed mothers. Therefore, maternal screening and counseling by trained general practitioners and professionals before and during pregnancy are recommended. © 2016, Tehran University of Medical Sciences (TUMS). All Rights Reserved
Prediction of flow in non prismatic compound open channel using artificial neural network
Each river in the world is unique. Some are gently curved, others are meander, and some others are relatively straight and skewed. The size of river geometry also changes from section to section longitudinally due to different hydraulic and surface conditions called non-prismatic channel. Much of the research work are found to be done on prismatic compound channels. There has also been a progress of work found for meandering channels. But an era which has been neglected is that of the work for non-prismatic compound channels. An effort has been made to scrutinize the research work related to non-prismatic channels in different types of flow conditions. An experimental observation has been made to investigate the velocity distribution, boundary shear stress distribution and energy loss of a compound channel with converging flood plain. The calculation of Depth average velocity, energy loss, boundary shear stress in non-prismatic compound channel flow is more complex. The prediction of the flow characteristics in compound channels with prismatic and non-prismatic floodplains is a challenging task for hydraulics engineers due to the three dimensional nature of the flow. Simple conventional approaches cannot predict the above mentioned flow characteristics with sufficient accuracy, hence in this area an easily implementable technique the Artificial Neural Network can be used for prediction, validation and analysis of the flow parameters mentioned. The model performed quite satisfactory when compared with the other conventional methods
Non-contact rack and pinion powered by the lateral Casimir force
The lateral Casimir force is employed to propose a design for a potentially
wear-proof rack and pinion with no contact, which can be miniaturized to
nano-scale. The robustness of the design is studied by exploring the relation
between the pinion velocity and the rack velocity in the different domains of
the parameter space. The effects of friction and added external load are also
examined. It is shown that the device can hold up extremely high velocities,
unlike what the general perception of the Casimir force as a weak interaction
might suggest.Comment: 4 pages, submitted for publication on 17 Jan 0
Superfluid Spin-down, with Random Unpinning of the Vortices
The so-called ``creeping'' motion of the pinned vortices in a rotating
superfluid involves ``random unpinning'' and ``vortex motion'' as two
physically separate processes. We argue that such a creeping motion of the
vortices need not be (biased) in the direction of an existing radial Magnus
force, nor should a constant microscopic radial velocity be assigned to the
vortex motion, in contradiction with the basic assumptions of the ``vortex
creep'' model. We point out internal inconsistencies in the predictions of this
model which arise due to this unjustified foundation that ignores the role of
the actual torque on the superfluid. The proper spin-down rate of a pinned
superfluid is then calculated and turns out to be much less than that suggested
in the vortex creep model, hence being of even less observational significance
for its possible application in explaining the post-glitch relaxations of the
radio pulsars.Comment: To be published in J. Low Temp. Phys., Vol. 139, May 2005 [Eqs 11,
15-17 here, have been revised and, may be substituted for the corresponding
ones in that paper
Evaluation of a wrist-worn photoplethysmography monitor for heart rate variability estimation in patients recovering from laparoscopic colon resection
To evaluate the accuracy of heart rate variability (HRV) parameters obtained with a wrist-worn photoplethysmography (PPG) monitor in patients recovering from minimally invasive colon resection to investigate whether PPG has potential in postoperative patient monitoring. 31 patients were monitored for three days or until discharge or reoperation using a wrist-worn PPG monitor (PulseOn, Finland) with a Holter monitor (Faros 360, Bittium Biosignals, Finland) as a reference measurement device. Beat-to-beat intervals (BBI) and HRV information collected by PPG were compared with RR intervals (RRI) and HRV obtained from the ECG reference after removing artefacts and ectopic beats. The beat-to-beat mean error (ME) and mean absolute error (MAE) of good quality heartbeat intervals obtained by wrist PPG were estimated as - 1.34 ms and 10.4 ms respectively. A significant variation in the accuracy of the HRV parameters was found. In the time domain, SDNN (9.11%), TRI (11.4%) and TINN (11.1%) were estimated with low relative MAE, while RMSSD (34.3%), pNN50 (139%) and NN50 (188%) had higher errors. The logarithmic parameters in the frequency domain (VLF Log, LF Log and HF Log) exhibited the lowest relative error, and for non-linear parameters, SD2 (7.5%), DFA alpha 1 (8.25%) and DFA alpha 2 (4.71%) were calculated much more accurately than SD1 (34.3%). The wrist PPG shows some potential for use in a clinical setting. The accuracy of several HRV parameters analyzed post hoc was found sufficient to be used in further studies concerning postoperative recovery of patients undergoing laparoscopic colon resection, although there were large errors in many common HRV parameters such as RMSSD, pNN50 and NN50, rendering them unusable. ClinicalTrials.gov Identifier: NCT04996511, August 9, 2021, retrospectively registeredPeer reviewe
Continuous and discrete Schrodinger systems with PT-symmetric nonlinearities
We investigate the dynamical behavior of continuous and discrete Schrodinger
systems exhibiting parity-time (PT) invariant nonlinearities. We show that such
equations behave in a fundamentally different fashion than their nonlinear
Schrodinger counterparts. In particular, the PT-symmetric nonlinear Schrodinger
equation can simultaneously support both bright and dark soliton solutions. In
addition, we study a two-element discretized version of this PT nonlinear
Schr\"odinger equation. By obtaining the underlying invariants, we show that
this system is fully integrable and we identify the PT-symmetry breaking
conditions. This arrangement is unique in the sense that the exceptional points
are fully dictated by the nonlinearity itself
Cell encapsulation in gelatin methacryloyl bioinks impairs microscale diffusion properties
Light-assisted bioprinted gelatin methacryloyl (GelMA) constructs have been used for cell-laden microtissues and organoids. GelMA can be loaded by desired cells, which can regulate the biophysical properties of bioprinted constructs. We study how the degree of methacrylation (MA degree), GelMA mass concentration, and cell density change mass transport properties. We introduce a fluorescent-microscopy-based method of biotransport testing with improved sensitivity compared to the traditional particle tracking methods. The diffusion capacity of GelMA with a higher MA significantly decreased compared to a lower MA. Opposed to a steady range of linear elastic moduli, the diffusion coefficient in GelMA varied when cell densities ranged from 0 to 10 × 106 cells/ml. A comparative study of different cell sizes showed a higher diffusivity coefficient for the case of larger cells. The results of this study can help bioengineers and scientists to better control the biotransport characteristics in light-assisted bioprinted microtissues and organoids
Diffusive transport of light in three-dimensional disordered Voronoi structures
The origin of diffusive transport of light in dry foams is still under
debate. In this paper, we consider the random walks of photons as they are
reflected or transmitted by liquid films according to the rules of ray optics.
The foams are approximately modeled by three-dimensional Voronoi tessellations
with varying degree of disorder. We study two cases: a constant intensity
reflectance and the reflectance of thin films. Especially in the second case,
we find that in the experimentally important regime for the film thicknesses,
the transport-mean-free path does not significantly depend on the topological
and geometrical disorder of the Voronoi foams including the periodic Kelvin
foam. This may indicate that the detailed structure of foams is not crucial for
understanding the diffusive transport of light. Furthermore, our theoretical
values for transport-mean-free path fall in the same range as the experimental
values observed in dry foams. One can therefore argue that liquid films
contribute substantially to the diffusive transport of light in {dry} foams.Comment: 8 pages, 8 figure
Theoretical Progression of Work and Life Relationship: A Historical Perspective
In this study we will discuss the historical changes in the work and life relationship which resulted in development of new theories. After an introduction to work-life relationships, different theories of work and life are presented in the second section of this paper. These theories are categories intro three generations based on their characteristics in the historical evolution of work-life studies. In the third section measures of work and life spillovers are described. In section four, critiques of the current methodologies which is being used in the work and life studies are presented. Discussion section which is presented in following section includes some arguments regarding the ways to select the most appropriate theories for work-life studies. Also in this section some recommendations are presented for enhancing the commonly used methodologies of the research on work and life relationships. Finally, in the last section, some recommendations for future studies are presented
Layered double hydroxide-based nanocomposite scaffolds in tissue engineering applications
Layered double hydroxides (LDHs), when incorporated into biomaterials, provide a tunable composition, controllable particle size, anion exchange capacity, pH-sensitive solubility, high-drug loading efficiency, efficient gene and drug delivery, controlled release and effective intracellular uptake, natural biodegradability in an acidic medium, and negligible toxicity. In this review, we study potential applications of LDH-based nanocomposite scaffolds for tissue engineering. We address how LDHs provide new solutions for nanostructure stability and enhance in vivo studies\u27 success
- …