333 research outputs found

    Fractal universe and quantum gravity

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    We propose a field theory which lives in fractal spacetime and is argued to be Lorentz invariant, power-counting renormalizable, ultraviolet finite, and causal. The system flows from an ultraviolet fixed point, where spacetime has Hausdorff dimension 2, to an infrared limit coinciding with a standard four-dimensional field theory. Classically, the fractal world where fields live exchanges energy momentum with the bulk with integer topological dimension. However, the total energy momentum is conserved. We consider the dynamics and the propagator of a scalar field. Implications for quantum gravity, cosmology, and the cosmological constant are discussed.Comment: 4 pages. v2: typos corrected; v3: discussion improved, intuitive introduction added, matches the published versio

    The use of nasal midazolam in reducing preoperative anxiety in children

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    Background: Surgery and anesthesia can cause a considerable distress with psychological consequences for children. This preoperative anxiety can lead to post operative emergence delirium, maladaptive behavioral changes such as night time crying, enuresis, feeding difficulties, apathy, and withdrawal.Objectives: The aim of this study is to investigate the effect of nasal midazolam as a routine intervention to reduce pre-operative anxiety and inducing anxiolysis in children undergoing day case procedure.Method: One hundred children were randomly allocated into two groups. The study group (N=50) were premedicated with nasal midazolam 0.2mg/kg and the control group (N=50) who received 0.04ml of normal saline. The children response to nasal administration was noticed and after 15 minutes children were taken to operating room. Anxiety at parental separation and at induction of anesthesia was measured using modified-Yale Preoperative Anxiety Scale.Results: Children who received nasal midazolam had a significantly better parental separation and induction of anesthesia. 88% of children who received nasal midazolam scored below 30-indicating absence of anxiety- on modified-Yale Preoperative Anxiety Scale compared to 32% in the control group. More than half of patients in both groups found nasal route to be unpleasant and stressful.Conclusion: For children undergoing elective brief surgical procedure, nasal midazolam is effective in reducing preoperative anxiety. Nasal midazolam was associated in more than half of patients with nasal irritation and crying, a route can not be recommended in children

    Fractional conservation laws in optimal control theory

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    Using the recent formulation of Noether's theorem for the problems of the calculus of variations with fractional derivatives, the Lagrange multiplier technique, and the fractional Euler-Lagrange equations, we prove a Noether-like theorem to the more general context of the fractional optimal control. As a corollary, it follows that in the fractional case the autonomous Hamiltonian does not define anymore a conservation law. Instead, it is proved that the fractional conservation law adds to the Hamiltonian a new term which depends on the fractional-order of differentiation, the generalized momentum, and the fractional derivative of the state variable.Comment: The original publication is available at http://www.springerlink.com Nonlinear Dynamic

    Laparoscopy for the management of impalpable testis

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    Background: Cryptorchidism is encountered in 21% of preterm infants, 2-4% of all full term boys and 1% of one year old boys.Objectives:To present our experience in the utilization of diagnostic laparoscopy for the management of children with impalpable testes.Method:This is a retrospective study conducted between March 2010 and December 2011. The medical records of boys with impalpable testis were reviewed. Diagnostic laparoscopic findings regarding presence, morphological state, and location of testis were analyzed. Special attention to how initial laparoscopy influenced subsequent surgical procedures and management.Results:Fifty four boys underwent laparoscopy with 76 impalpable testes. Forty testes were unilateral impalpable testes, two third of them were left sided. Thirty seven testes were intraabdominal, eight of them were atrophied and excised laparoscopically. Twenty nine of them were viable, 90% of them underwent first stage Fowler-Stephens procedure, while the rest underwent primary laparoscopic orchidopexy. Vas and spermatic vessels were seen entering inguinal canal in 25 testes. This group had immediate inguinal exploration, 22 of testes underwent orchidopexy and three orchidectomy. Fourteen boys found to blind end vas and vessels with no further treatment needed.Conclusions: Laparoscopic exploration should be performed because it accurately identifies and localizes the missing testis. In addition, it facilitates the planning of definitive surgical management of orchidopexy, staged orchidopexy or orchidectomy. So we recommend that initial laparoscopic exploration should be performed for patient with impalpable testis.Keywords:Impalpable testis, Laparoscopy, Orchidopexy, Jordan

    Multi-band D-TRILEX approach to materials with strong electronic correlations

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    We present the multi-band dual triply irreducible local expansion (D-TRILEX) approach to interacting electronic systems and discuss its numerical implementation. This method is designed for a self-consistent description of multi-orbital systems that can also have several atoms in the unit cell. The current implementation of the D-TRILEX approach is able to account for the frequency- and channel-dependent long-ranged electronic interactions. We show that our method is accurate when applied to small multi-band systems such as the Hubbard-Kanamori dimer. Calculations for the extended Hubbard, the two-orbital Hubbard-Kanamori, and the bilayer Hubbard models are also discussed

    Variations in Students’ Learning Habits and Behavior Patterns in Light of the Technological Innovations and Connectivist Theory of Learning

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    The “Tsunami of spread of knowledge and modern technological means led to the emergence of new mental skills and modes of learning among learners. Consequently, students’ learning was affected by the new knowledge networks. As such, this study aimed at investigating the change in the learning habits of learners in light of the technological development, and to study the impact of digital instruments and applications on the development/change of the learners’ study habits. The study utilized a qualitative approach with a descriptive analytical design, where semi-structured interviews were created and conducted with three age groups: three adult learners who studied before technological development, five secondary school students, and four tertiary university students. Research results revealed the persistence of some traditional learning habits among school students, the development of study habits linked to modern technological means, and the development of modern technical skills such as Internet search. Some factors affecting learning habits appeared; specifically, the nature of the study task, teaching strategies, and student specialization. Some digital skills have been diagnosed for each category, like online searching skills, staying connected to networks, communication skills, the skills of self-organization, and the control of smart devices. In light of its findings, the study ended up with a set of recommendations for future research, and other recommendations for practice. Keywords: Learning habits, connectivism, digital learners, learning skills, learning instruments

    Effect of vitamin D replacement on maternal and neonatal outcomes: a randomised controlled trial in pregnant women with hypovitaminosis D. A protocol

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    Introduction: The vitamin D recommended doses during pregnancy differ between societies. The WHO guidelines do not recommend routine prenatal supplementation, but they underscore the fact that women with the lowest levels may benefit most. The effects of routine supplementation during pregnancy on maternal and neonatal clinical outcomes have not been investigated in the Middle East, where hypovitaminosis D is prevalent. Our hypothesis is that in Middle Eastern pregnant women, a vitamin D dose of 3000?IU/day is required to reach a desirable maternal 25-hydroxyvitamin D [25(OH)D] level, and to positively impact infant bone mineral content (BMC).Methods and analysis: This is a multicentre blinded randomised controlled trial. Pregnant women presenting to the Obstetrics and Gynaecology clinics will be approached. Eligible women will be randomised to daily equivalent doses of cholecalciferol, 600?IU or 3000?IU, from 15 to 18?weeks gestation until delivery. Maternal 25(OH)D and chemistries will be assessed at study entry, during the third trimester and at delivery. Neonatal anthropometric variables and 25(OH)D level will be measured at birth, and bone and fat mass assessment by dual-energy X-ray absorptiometry scan at 1?month. A sample size of 280 pregnant women is needed to demonstrate a statistically significant difference in the proportion of women reaching a 25(OH)D level ?50?nmol/L at delivery, and a difference in infant BMC of 6 (10)g, for a 90% power and a 2.5% level of significance. The proportions of women achieving a target 25(OH)D level will be compared between the two arms, using ?2. An independent t test will be used to compare mean infant BMC between the two arms. The primary analysis is an intention-to-treat analysis of unadjusted results.Ethics and dissemination: The protocol has been approved by the Institutional Review Board at the American University of Beirut-Lebanon (IM.GEHF.22). The trial results will be published in peer-reviewed medical journals and presented at scientific conferences.Trial registration number: NCT02434380.<br/

    Towards fostering the role of 5G networks in the field of digital health

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    A typical healthcare system needs further participation with patient monitoring, vital signs sensors and other medical devices. Healthcare moved from a traditional central hospital to scattered patients. Healthcare systems receive help from emerging technology innovations such as fifth generation (5G) communication infrastructure: internet of things (IoT), machine learning (ML), and artificial intelligence (AI). Healthcare providers benefit from IoT capabilities to comfort patients by using smart appliances that improve the healthcare level they receive. These IoT smart healthcare gadgets produce massive data volume. It is crucial to use very high-speed communication networks such as 5G wireless technology with the increased communication bandwidth, data transmission efficiency and reduced communication delay and latency, thus leading to strengthen the precise requirements of healthcare big data utilities. The adaptation of 5G in smart healthcare networks allows increasing number of IoT devices that supplies an augmentation in network performance. This paper reviewed distinctive aspects of internet of medical things (IoMT) and 5G architectures with their future and present sides, which can lead to improve healthcare of patients in the near future

    Fractional Action Cosmology with Power Law Weight Function

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    Motivated by an earlier work on fractional-action cosmology with a periodic weight function [1], we extend it by choosing a power-law weight function in the action. In this approach, we obtain a varying gravitational coupling constant. We then model dark energy in this paradigm and obtain relevant cosmological parameters.Comment: 12 pages, 9 figures, Contributed talk published in the proceedings of "3rd Italian-Pakistani Workshop on Relativistic Astrophysics

    Healthy food and determinants of food choice on online food delivery applications.

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    Online food delivery applications (OFD apps) provide consumers with a wide range of options to choose from. The present study aimed to assess the usage of OFD apps and investigate the factors that affect food choices with a special emphasis on healthy food choices and hygiene. A cross-sectional study among food delivery application users in Jordan was conducted using an online questionnaire between March and May 2022. A total of 675 eligible subjects participated in the study. Consumers' demographic characteristics, data on consumers' use of OFD apps, consumers' perceptions of healthy food availability in OFD apps, and consumers' attitudes toward food safety and delivery hygiene were collected and analyzed. About 64% of the studied sample used OFD apps weekly. Fast food was the most popular option for ordering (87.1%) and lunchtime was the most preferred time to order food (67.3%) for most of the respondents. Respondents' perceptions of a "healthy meal" was associated with the presence of a variety of vegetables in the meal. Food price, food appearance, time of delivery, macronutrient content information, the availability of healthy options, and considering vegetables as part of a healthy meal were determinants of consumer food choice (p<0.05). The findings suggest that the online food environment in Jordan was perceived to be unhealthy. Nevertheless, the convenient nature and the popularity of OFD apps hold great potential to promote healthy eating among consumers
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