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Introduction: Fractures are a common childhood presentation to the emergency department (ED). While ED providers are aware of treating pain, we are less aware of the functional impact of these fractures. Eighty percent of children with a fracture experience compromise in their daily function. Understanding the functional outcomes of fractures will help optimize discharge instructions for at-home care. The primary objective of our study was to describe caregivers' perspectives on the impact of their child's fracture on: (1) child functioning, (2) caregiver functioning and (3) family life. Methods: We performed a qualitative study interviewing caregivers of children (5 to 11 years) who received care for acute (< 24 hours old), non-operative long bone fractures at a Canadian tertiary care pediatric ED. Audio-recorded, semi-structured telephone interviews were completed 1-2 weeks post-ED visit, until thematic saturation was achieved. Transcripts were read and coded by two researchers concurrent with data collection. We applied content analysis to the interview material, explicating themes to summarize the data utilizing NVivo software. Results: Twenty-five interviews were completed. Most children (23/25) suffered upper extremity fractures and most participants were mothers (21/25). All caregivers reported a change in their child's function. The most commonly affected areas included: sleep, play and activities of daily living (ADL's; ie. dressing, bathing, eating). Children were impacted by pain and related negative emotional responses. All children required additional help from their caregivers to carry out ADL's. Strategies included changing household routines and missing work. Importantly, caregivers described a disrupted family dynamic. Adapting to their injured child's functional deficits and caring for pain and distress took time and attention away from the household's previously well-functioning routine. This burden was felt by all family members. Key concerns from caregivers included pain management, fracture healing/complications, and regression of their child's independence. Conclusion: Function is universally impaired in younger children with fractures. We suggest 5 main points to include in discharge instructions: (1) monitoring pain and providing analgesia, (2) helping children with ADL's, even if previously independent, (3) allotting extra time for morning and bedtime routines, (4) offering safe choices for play and (5) coaching children in positive thinking and problem-solving.
Cystic echinococcosis (CE) is a zoonotic disease caused by a complex of species known as Echinococcus granulosus sensu lato. CE is endemic in Argentina, Chile, Peru, Uruguay and the South part of Brazil. In contrast, little is known regarding the presence of CE in Bolivia. In this study, 35 cysts isolated from livestock (mostly from the Department of La Paz) and 3 from humans (La Paz, Oruro and Potosi) were genetically characterized analysing the sequence of the cox1 gene (1609 bp). In total, 30 cysts (from La Paz, Cochabamba and Beni) were characterized as E. granulosus sensu stricto (3 fertile and 4 non-fertile cysts from sheep, 8 fertile and 12 non-fertile cysts from cattle and 3 fertile cysts from humans). A detailed analysis of the cox1 haplotypes of E. granulosus s.s. is included. Echinococcus ortleppi (G5) was found in 5 fertile cysts from cattle (from La Paz and Cochabamba). Echinococcus intermedius (G7) was identified in 3 fertile cysts from pigs (from Santa Cruz). Additionally, E. granulosus s.s. was detected in 4 dog faecal samples, while E. ortleppi was present in other two dog faecal samples. The implications of these preliminary results in the future implementation of control measures are discussed.
This paper proposes an adaptive robust impedance control for a single-link flexible arm when it encounters an environment at an unknown intermediate point. First, the intermediate collision point is estimated using a collision detection algorithm. The controller, then, switches from free to constrained motion mode. In the unconstrained motion mode, the exerted force to environment is nearly zero. Thus, the reference trajectory is a prescribed desired trajectory in position control. In the constrained motion mode, the reference trajectory is determined by the desired target dynamic impedance. The simulation results demonstrate the efficiency of proposed control scheme.
Introduction: Intranasal dexmedetomidine (IND) is an emerging agent for procedural distress in children. However, studies to date have been limited by small samples and imprecise estimates of effect size. We sought to summarize the evidence on the effectiveness of IND for procedures associated with distress in children. Methods: We performed electronic searches of MEDLINE (1946-2018), EMBASE (1980-2018), Google Scholar (2018), CINAHL (1981-2018), Cochrane Central Register of Controlled Trials (2018), 6 clinical trials registries and conference proceedings (2010-2018). Title searches, data abstraction, and risk of bias assessments were performed in duplicate. We included all published and unpublished, randomized and quasi-randomized trials of IND for procedures in children younger than 19 years of age without language restriction. The methodological quality of studies was evaluated using the Cochrane Collaboration's Risk of Bias tool. The primary outcome was the proportion of participants that were deemed to be adequately sedated for the procedure. Results: Of 661 studies, 18 met inclusion criteria. Trials involved 2128 participants, age 1 month - 14 years (836, 39.3% females), who received IND 1 - 4 mcg/kg either by drops (n = 12), atomizer (n = 4), or both (n = 2). 12 trials were eligible for meta-analysis. 13 trials used validated instruments to assess sedation. All studies except one were associated with low or moderate risk of bias. For painful procedures (IV insertion; laceration repair; dental extraction), the pooled OR (95% CI) for adequate sedation and need for additional analgesia was non-significant [1.19 (0.53, 2.65)] and [2.16 (0.62, 7.49)], respectively (n = 5). For non-painful procedures (diagnostic imaging), the corresponding pooled OR (95% CI) favored IND [3.04 (1.58, 5.82)] and [4.44 (2.11, 9.35)], respectively (n = 7). Time to onset and duration of sedation ranged from 13-31 minutes and 41-91.5 minutes, respectively. For adverse effects, the pooled OR (95% CI) was not significantly different between IND and comparators [0.58 (0.22, 1.55] and there were no serious adverse events. Conclusion: IND at doses 1 to 4 mcg/kg are safe and adequately sedate children undergoing non-painful procedures, although the ease of administration must be weighed against the risk of prolonged sedation. Additional trials with larger sample sizes and greater methodologic rigor are needed for painful emergency department procedures such as laceration repair and IV insertion.
Surgery for CHD has been slow to develop in parts of the former Soviet Union. The impact of an 8-year surgical assistance programme between an emerging centre and a multi-disciplinary international team that comprised healthcare professionals from developed cardiac programmes is analysed and presented.
Material and methods
The international paediatric assistance programme included five main components – intermittent clinical visits to the site annually, medical education, biomedical engineering support, nurse empowerment, and team-based practice development. Data were analysed from visiting teams and local databases before and since commencement of assistance in 2007 (era A: 2000–2007; era B: 2008–2015). The following variables were compared between periods: annual case volume, operative mortality, case complexity based on Risk Adjustment for Congenital Heart Surgery (RACHS-1), and RACHS-adjusted standardised mortality ratio.
A total of 154 RACHS-classifiable operations were performed during era A, with a mean annual case volume by local surgeons of 19.3 at 95% confidence interval 14.3–24.2, with an operative mortality of 4.6% and a standardised mortality ratio of 2.1. In era B, surgical volume increased to a mean of 103.1 annual cases (95% confidence interval 69.1–137.2, p<0.0001). There was a non-significant (p=0.84) increase in operative mortality (5.7%), but a decrease in standardised mortality ratio (1.2) owing to an increase in case complexity. In era B, the proportion of local surgeon-led surgeries during visits from the international team increased from 0% (0/27) in 2008 to 98% (58/59) in the final year of analysis.
The model of assistance described in this report led to improved adjusted mortality, increased case volume, complexity, and independent operating skills.
In this chapter, we provide a high-level introduction to interference management in wireless networks, including a historical perspective on wireless cellular networks, and an overview of the remaining chapters in the book. We also summarize the notation used in the book.
Interference Management in Cellular Networks: A Historical Perspective
Managing interference from other users sharing the same frequency bands has been the key driver for mobile wireless communications. The first wireless phone systems served as extensions to the wired public switched telephone network . These systems were “single cell” systems in the sense that mobile terminals could be connected to only one basestation during a call, with the call being lost when out of range of the basestation, akin to losing an FM radio signal while driving out of range of the station. Interference in these networks could be managed by simply orthogonalizing the users in the time–frequency plane, i.e., through the use of time-division multiple-access (TDMA) or frequency-division multiple-access (FDMA), or some combination of the two. Interference between basestations operating in the same frequency band was managed by ensuring that they are geographically far apart, again akin to the way in which radio stations operating in the same frequency band are placed.
A major breakthrough toward improving both the capacity and the mobility in wireless phone systems came with the introduction of the cellular concept . In the cellular system design, a given geographical region is split into contiguous regions called “cells,” without any gaps in coverage. The system is designed so that cells that use the same frequency band are far enough from each other to cause little interference to each other. The number of different frequency bands is called the reuse factor of the system. The reuse factor is a measure of spectral efficiency in the system, with a larger reuse factor corresponding to a smaller efficiency. A key innovation in the cellular concept is the introduction of handoff between neighboring cells operating in different frequency bands, which allows a mobile user to maintain a continuous connection while moving through the geographical region. Interference management within each of the cells is achieved by orthogonalizing the users in the time–frequency plane.
Our treatment of the CoMP concept of communication has been restricted so far to transmission schemes and their applications in the cellular downlink. In this chapter, we investigate whether the ideas studied for enabling rate gains and minimizing delay requirements through CoMP can be applied to reception schemes and their applications in the cellular uplink. Throughout our discussion of CoMP transmission, we assumed that messages are distributed through a backhaul network to transmitters. More specifically, we assumed that sharing of information between transmitters occurs through sharing of digital messages, instead of assuming that quantized analog signals are being shared. This is a natural assumption when considering the cellular downlink for the following reasons. First, sharing of analog signals is prone to quantization errors, which complicate the interference management problem, and make it harder to obtain clear insights through information-theoretic analyses. Second, since our purpose is to model fairly general scenarios for cellular networks, and in particular, those anticipated in next generation wireless networks, it is natural to assume that a message is being delivered from a central controller (or basestation controller) to each basestation transmitter. This is the case even if we are not considering cooperative transmission, and hence it is also natural to extend this assumption with a more powerful backhaul to allow for delivering the digital message to more than one basestation transmitter. For the considered setting of cellular uplink, the first reason mentioned above will still hold. However, the second aspect is different. Here, we can think of two different ways for cooperative reception. The first is when sharing of analog received signals is permitted; we call such schemes CoMP reception schemes and we discuss information-theoretic results for this case in Section 8.1. The second is when only sharing of decoded messages is permitted; we call this the message passing model and we discuss information-theoretic results for this case in Section 8.2.
There are noticeable similarities between the message passing model and the CoMP transmission schemes that are based on zero-forcing. By passing one message from one basestation to another through the backhaul, the interference caused by this message at exactly one receiver could be eliminated. However, unlike the downlink case, when the interference caused by a message is canceled at one receiver through cooperation, it does not propagate to other receivers.
An important requirement of next-generation (5G) wireless systems is the ability to autonomously adjust to varying environmental conditions. Our focus in this chapter is to analyze information-theoretic models of interference networks that capture the effect of deep fading conditions through introducing random link erasure events in blocks of communication time slots.More specifically, in order to consider the effect of long-term fluctuations (deep fading or shadowing), we assume that communication takes place over blocks of time slots, and independent link erasures occur with probability p in each block.
We can observe through the results presented in Chapters 5–8 that conclusions related to the optimal associations of mobile terminals to basestations and the achievable DoF differ dramatically based on the network topology. For example, under the maximum transmit set size constraint for the downlink, local cooperation cannot lead to a gain in the achieved asymptotic per-user DoF for the fully connected channel. However, local cooperation is optimal for locally connected channels and can lead to achieving scalable DoF gains, and the optimal assignment of messages to transmitters depends on the connectivity parameter L. In practice, the topology may change due to deep fading conditions (see, e.g., ) or even intentionally to exploit spectrum opportunities (see, e.g., ). In this chapter, we extend our DoF results to dynamic interference networks where a fixed assignment of messages is selected to achieve average DoF optimal performance in networks with changing topology.
In , the authors analyzed the average capacity for a point-to-point channel model where slow changes result in varying severity of noise. We apply a similar concept to interference networks by assuming that slowly changing deep fading conditions result in link erasures.We consider the linear interference network (L=1) that was introduced in Chapter 6, and look at two fading effects: long-term fluctuations that result in link erasures over a complete block of time slots, and short-term fluctuations that allow us to assume that any specific joint realization for the non-zero channel coefficients will take place with zero probability. We study the problem of achieving the optimal average degrees of freedom under a maximum transmit set size constraint (5.16). We note that the problem studied in Chapter 6 reduces to the case of no erasures.
In the previous two chapters, we have considered cooperative transmission schemes that are constrained by the number of transmitters to which each message can be assigned. While meeting a backhaul capacity limit by a per-message constraint can have its analytical advantages, such as reducing a difficult information-theoretic problem to a simple combinatorial one, this approach suffers from a few important drawbacks.
For one, the maximum transmit set size constraint may not reflect most practical scenarios for two reasons. First, because fractional reuse across different resource (e.g., frequency or time) slots can be used to achieve an equal load on the backhaul per message, it may not make sense to impose a maximum transmit set size constraint for each channel use. Secondly, the maximum transmit set size constraint may not reflect the nature of the backhaul link, as we will discuss further below.
Also, as we have discussed in the previous chapter, the optimal solutions for the maximum transmit set size constraint may not fully utilize the constraint; i.e., for the optimal solution, some messages need not be assigned to the allowed maximum number of transmitters. We have seen in Chapter 6 that this is the case for the optimal schemes for linear interference networks, as well as for general locally connected networks where we impose the restriction of using only zero-forcing coding schemes.
The appropriate constraint to consider for the assignment of messages to transmitters should depend on the nature of the backhaul link used in practice (see, e.g., [69, 86]). For example, in the context of heterogeneous networks, the backhaul can be a wireless network, and an overall backhaul load constraint would be a more appropriate choice. On the other hand, for the case of wireline or optical fiber backhaul links, the maximum transmit set size constraint can be useful. However, even with wireline backhaul links, an average transmit set size constraint can allow for flexible solutions that interleave the use of the backhaul links over multiple communication sessions. In general, a constraint that bounds the average transmit set size is more relevant to practice than imposing a maximum constraint on each transmit set size. We show in this chapter how the solutions for the CoMP transmission problem provided under the maximum transmit set size constraint can be used to find solutions under an average transmit set size or backhaul load constraint.