Equal Periods Research Articles

Individuals with Autism Spectrum Disorders Have Equal Success Rate But Require Longer Periods of Systematic Desensitization than Control Patients to Complete Ambulatory Polysomnography

Polysomnography (PSG) is the gold standard for the assessment of sleep, yet the extensive apparatus required for monitoring with PSG can be difficult to tolerate, particularly in children. Clinical populations, such as those with anxiety or tactile sensitivity, may have even greater difficulty tolerating the PSG equipment. This study evaluated an innovative protocol for obtaining full PSG in individuals diagnosed autism spectrum disorders (ASD) or developmental delay (DD), as well as typically developing controls (TD). The primary aim was to assess whether this protocol was equally successful for obtaining PSG between these groups. One hundred sixty-one individuals were recruited for participation; 93 with a diagnosis of ASD, 23 with a diagnosis of DD, and 45 TD. The participants and families were instructed on a procedure of systematic desensitization to the ambulatory PSG equipment; PSG was performed in the home of the participant. PSG was successfully attained in 144 (89.4%) participants. There was no difference in completion rate by diagnosis (p = 0.1), though younger age (p = 0.018) and duration of desensitization (p = 0.024) did predict PSG failure. Further, it was found that individuals with ASD took longer to desensitize to the equipment (16.08 d), than those with DD (8.04 d) or TD (0.98 d). Systematic desensitization to PSG equipment, in combination with PSG completed in the home, allows for individuals with ASD to be equally successful in completing PSG, though they do take longer to acclimate to the equipment.

Benefits of Bifidobacterium breve M-16V Supplementation in Preterm Neonates - A Retrospective Cohort Study.

BackgroundSystematic reviews of randomised controlled trials report that probiotics reduce the risk of necrotising enterocolitis (NEC) in preterm neonates.AimTo determine whether routine probiotic supplementation (RPS) to preterm neonates would reduce the incidence of NEC.MethodsThe incidence of NEC ≥ Stage II and all-cause mortality was compared for an equal period of 24 months ‘before’ (Epoch 1) and ‘after’ (Epoch 2) RPS with Bifidobacterium breve M-16V in neonates <34 weeks. Multivariate logistic regression analysis was conducted to adjust for relevant confounders.ResultsA total of 1755 neonates (Epoch I vs. II: 835 vs. 920) with comparable gestation and birth weights were admitted. There was a significant reduction in NEC ≥ Stage II: 3% vs. 1%, adjusted odds ratio (aOR) = 0.43 (95%CI: 0.21–0.87); ‘NEC ≥ Stage II or all-cause mortality’: 9% vs. 5%, aOR = 0.53 (95%CI: 0.32–0.88); but not all-cause mortality alone: 7% vs. 4%, aOR = 0.58 (95% CI: 0.31–1.06) in Epoch II. The benefits in neonates <28 weeks did not reach statistical significance: NEC ≥ Stage II: 6% vs. 3%, aOR 0.51 (95%CI: 0.20–1.27), ‘NEC ≥ Stage II or all-cause mortality’, 21% vs. 14%, aOR = 0.59 (95%CI: 0.29–1.18); all-cause mortality: 17% vs. 11%, aOR = 0.63 (95%CI: 0.28–1.41). There was no probiotic sepsis.ConclusionRPS with Bifidobacterium breve M-16V was associated with decreased NEC≥ Stage II and ‘NEC≥ Stage II or all-cause mortality’ in neonates <34 weeks. Large sample size is required to assess the potential benefits of RPS in neonates <28 weeks.

Maintenance Electroconvulsive Therapy in Severe Bipolar Disorder: A Retrospective Chart Review.

The aim of this study was to evaluate the effectiveness of continuation and maintenance electroconvulsive therapy (C/M-ECT) in patients with bipolar or schizoaffective disorder. We reviewed the charts of all patients diagnosed with a bipolar or schizoaffective disorder treated with C/M-ECT from August 2009 until December 2013. We gathered demographic data and treatment variables (electrode placement, stimulus dose, and concomitant use of medication; number of C/M-ECT sessions; and number of new ECT courses). Primary outcome measure was the number of hospitalization days during C/M-ECT as compared with an equal period before starting the index course. Twenty women (64.5%) and 11 men (35.5%) with a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition bipolar disorder (n = 22, 71%) or schizoaffective disorder (n = 9, 29%) received C/M-ECT. The mean (SD) age was 51.23 (14.86; range, 28-74) years. Before the start of the index ECT, patients had a mean of 290 hospitalization days (248.4 days, full hospitalization; 41.6 days, partial hospitalization), whereas during C/M-ECT, they had a mean of 214.7 hospitalization days (85.4 days, full hospitalization; 129.3 days, partial hospitalization). The number of readmissions before ECT was 2.13, whereas during C/M-ECT, it decreased to 1.48. Only the decrease in number of full hospitalization days was significant. Most patients (n = 23, 74.19%) needed an acute course of ECT during M-ECT. Maintenance ECT seems to significantly reduce the number of full hospitalization days in patients with severe bipolar or schizoaffective disorder.

On adatomic-configuration-mediated correlation between electrotransport and electrochemical properties of graphene

The electron-transport properties of adatom–graphene system are investigated for different spatial configurations of adsorbed atoms: when they are randomly-, correlatively-, or orderly-distributed over different types of high symmetry sites with various adsorption heights. The results are obtained numerically using the quantum-mechanical Kubo–Greenwood formalism. A band gap may be opened only if ordered adatoms act as substitutional atoms, while there is no band gap opening for adatoms acting as interstitial atoms. The type of adsorption sites strongly affect the conductivity for random and correlated adatoms, but practically does not change the conductivity when they form ordered superstructures with equal periods. Depending on electron density and type of adsorption sites, the conductivity for correlated and ordered adatoms is found to be enhanced in dozens of times as compared to the cases of their random positions. The correlation and ordering effects manifest weaker or stronger depending on whether adatoms act as substitutional or interstitial atoms. The conductivity approximately linearly scales with adsorption height of random or correlated adatoms, but remains practically unchanged with adequate varying of elevation of ordered adatoms. Correlations between electron transport properties and heterogeneous electron transfer kinetics through potassium-doped graphene and electrolyte interface are investigated as well.

Risk factors for surgical site infection after instrumented fixation in spine trauma

Surgical site infection (SSI) represents a significant complication after instrumented fixation in spine trauma. Institutional practice changes have emphasized early fracture correction, shortened intraoperative times, early ambulation, and prompt nutritional supplementation. This retrospective study evaluates the senior author’s experience of instrumented spinal trauma SSI occurring at a single Level I trauma center over two equal and contiguous time periods, 2005–2007 (before nutritional supplementation was added to the institutional protocol) and 2008–2010 (after nutritional supplementation was added). This study assessed whether SSI varied depending on the primary surgical site and/or by the chosen approach. Lastly, the incidence of SSI among demographic and other clinical variables was evaluated. In total, 358 patients underwent an index procedure for spinal trauma correction. Fourteen patients developed a SSI requiring reoperation for an incidence of 4.0%.In assessing nutritional supplementation, the probability of infection tended to be lower in the supplemented group (3.7%) than the pre-supplement group (4.3%), but this did not reach significance. The difference in approach for the cervical spine was statistically significant (p=0.045) with rates of infection via posterior approach at 8.1% and no infections via anterior approach. Presence of comorbidities (p=0.03) and time to surgery >3days (p=0.006) were predictors of developing SSI. Benefit is shown from early surgical correction of spinal trauma patients in the reduction of postoperative SSI. Nutritional supplementation may provide a small reduction in infections in the spine trauma population.

Multiwindow Real-Valued Discrete Gabor Transform and Its Fast Algorithms

Based on the biorthogonal analysis approach, a multiwindow real-valued discrete Gabor transform (M-RDGT) for periodic sequences is presented to efficiently analyze the dynamic time-frequency content of a signal containing components with multiple and/or time-varying frequencies. The M-RDGT offers a computationally efficient implementation as well as a real-valued formulation of the multiwindow complex-valued discrete Gabor transform (M-CDGT). The completeness condition of the M-RDGT is proved to be equivalent to its biorthogonality constraint between analysis windows and synthesis windows. The M-RDGT can utilize the fast discrete Hartley transform algorithms for fast computation and has a simple relationship with the M-CDGT such that its coefficients can be directly computed from the M-RDGT coefficients. Therefore, the M-RDGT offers an efficient method to compute the M-CDGT. Since the analyzed sequence, analysis and synthesis windows in the existing M-CDGT must have an equal period, if the period of a sequence is very long, solving its windows requires a huge amount of computation and memory and could lead to numerical instability. To overcome this problem, a modified M-RDGT for long-periodic (or even infinite) sequences is presented and its corresponding biorthogonality constraint between analysis windows and synthesis windows is modified, in which the period of the analysis and synthesis windows is independent of the period of a analyzed sequence so that one can apply short windows to process any long-periodic (or even in finite) sequence. Finally, the multirate-based parallel implementation of the M-RDGT is presented, which has shown to be effective and fast for time-frequency analysis.

Trend definition or holding strategy: What determines the profitability of candlestick charting?

Abstract We ask what determines the profitability of candlestick trading strategies. Is it the definition of trend and/or the holding strategy that one uses in candlestick charting analysis? To answer this, we systematically consider three definitions of trend and four holding strategies. Applying candlestick trading strategies to the DJIA component data, we find that regardless of which definition of trend is used, eight three-day reversal patterns with a Caginalp–Laurent holding strategy are profitable when we set the transaction cost at 0.5% and after we account for data-snooping bias, while the patterns with a Marshall–Young–Rose holding strategy are not profitable. For sensitivity analysis, we also find that our results are not qualitatively changed on a lower transaction cost of 0.1%, or when we conduct the subsample analyses based on three equal periods and three distinct market conditions. When considering a more volatile market, evidence in favor of candlestick trading strategies is strengthened.

Simplified staged-homogenous Markov model for flexible pavement performance prediction

This paper presents a simplified staged-homogenous Markov model proposed for predicting future pavement conditions at the project level with minimal time and effort. The analysis period is divided into equal staged-time periods with each represented by a unique transition probability matrix. The deterioration transition probabilities are expected to increase over time due to the progressively increasing traffic loading and gradually degrading pavement structure. Therefore, the deterioration transition probabilities associated with staged-time periods are estimated from multiplying the present deterioration transition probabilities by appropriate constants called C constants. The C constants are to be estimated from minimising the sum of squared errors (SSE) defined as the differences between the predicted and observed distress ratings (DRs). A simplified sequential trial-and-error minimisation approach is proposed for obtaining the best estimates of the C constants. The presented sample problem has indicated the effectiveness of the proposed staged-homogenous Markov model in predicting future pavement DRs using five-year staged-time periods. This has been validated using three key performance indicators, namely the generated best-fit performance curves, minimum SSE, and staged-performance ratios.

Teaching-learning-based optimization with variable-population scheme and its application for ANN and global optimization

A teaching-learning-based optimization algorithm (TLBO) which uses a variable population size in the form of a triangle form (VTTLBO) is proposed in the paper. The main goal of the proposed method is to decrease the computing cost of original TLBO and extend it for optimizing the parameters of artificial neural network (ANN). In the proposed algorithm, the evolutionary process is divided into some equal periods according to the maximal generation. The population size in each period is changed in form of triangle. In the linear increasing phase of population’s number, some new individuals are generated with gauss distribution by using the adaptive mean and variance of the population. In the linear decreasing phase of population׳s number, some highly similar individuals are deleted. To compare the performance of the proposed method with some other methods, Saw-tooth teaching-learning-based optimization algorithm is also designed with simulating the basic principle of Saw-tooth genetic algorithm (STGA), and some other EAs with the fixed population size are also simulated. A variety of benchmark problems and system modeling and prediction problems with ANN are tested in this paper, the results indicate that the computation cost of the given method is small and the convergence accuracy and speed of it are high.

A new approach to Saturn's periodicities

AbstractSaturn's magnetospheric periodicities are commonly thought to have a dual nature, one period originating from the southern hemisphere and a slightly different period from the northern. Both periods vary a few percent over time intervals of years and apparently merged a few months after Saturn equinox. These periodicities have not been explained. The dual‐period waveform is generally represented as the superposition of two sinusoids with nearly equal periods. However, dual‐period waves can also result from an amplitude modulation of a carrier periodicity, from frequency modulation of the carrier, from random phase jumps in the carrier, and from small, random changes in the period itself. While such simple phenomena are well known in the radio community, they can serve as possible explanations for how a single planetary period can appear as the dual (or multiple) periods observed in Saturn's magnetosphere. Candidates for modulation and randomization include the solar wind pressure and speed, the orbital periods of moons of Saturn, or even the trajectory of the Cassini orbiter itself.

A Comparison of Use Patterns of Media Types in Landscape Architecture

In 1982, Environmental & Landscape Architecture(ELA), the first off-line printed media in Landscape Architecture, and in 2008, Lafent, on-line internet media, were published. The two media have developed along with the growth of the Landscape Architecture market. The total amount of information in Landscape Architecture area has been increased with knowledge and information-based generation, and its quantitative as well as qualitative needs have grown bigger. This study, therefore, compared and analyzed use orientations of the two media, focusing on the motivation of information use.For the study data, 768 samples collected by survey of subscribers of ELA and members of Lafent were used. As a result of data analysis, the two groups were clearly different in general attributes including gender, age, education, occupation, and the main task. For the main motive of use, ‘acquiring general landscaping knowledge’ for ELA, and ‘news and information in landscape architecture area’ were selected. Thus, the purposes of ‘learning’ for ELA and ‘keeping trend’ for Lafent were a lot. The periods of use of the two media were significantly different. ‘More than 5 years’ and ‘less than a year’ groups of ELA were more than those of Lafent. On the other hand, Lafent which has much shorter history had equal periods of use by category. Like the above results, demand markets are somewhat overlapped between the two journals, but independent areas by demander characteristics and motivational difference exist. Such results are assumed to be the consequences from the information content difference between prints and internet added by difference of general characteristics of demanders. Therefore, it is inferred that the two media needs to establish their direction in the future after considering such differences of demander composition and motivation. Keywords: printed media, internet media, motivation, knowledge information, news information

Fault‐block rotation controlling the distribution of fluvial sediments; a quantitative test on a Lower Pennsylvanian (Carboniferous) cyclothem succession

AbstractDepositional models of axial fluvial systems in half‐grabens predict that the fluvial‐sandstone percentage increases towards the downthrown side of a fault, because channel systems tend to migrate to the area of maximum subsidence. This migration is at the expense of mudstone, but floodplain deposition occurs near faults occasionally. The models assume gradual, transverse tilting and no external base‐level change, and their applicability to cases involving tectonics and/or sea‐level change may therefore be restricted. Here, a quantitative analysis is presented on a subsurface data set from a Lower Pennsylvanian cyclothem succession, which formed under conditions of differential subsidence and fluctuating sea‐level. The studied interval is wedge‐shaped and shows a systematic thickness increase from 165 to 245 m, controlled by syndepositional fault‐block tilting. It comprises three depositional units, bounded by coal groups. These units display an upward change from wedge‐shaped (75 to 120 m) to tabular (42 to 55 m). Despite their variable thickness, the units contain almost equal amounts of ca 45 m of floodplain deposits, plus ca 5 m of encased channel sandstones, in all boreholes. Where units are thicker, the remaining thickness comprises fluvial‐braidplain sandstone. This arrangement indicates that the units represent equal time periods, during which background subsidence allowed the deposition of thin channel sands and overbank mud on a level floodplain. Occasional tilting produced additional accommodation space, which was completely filled by sand‐dominated braided systems. The temporary cessation of floodplain‐mud deposition suggests that aggradation of the river system could not keep up with floodplain tilting. In addition, bypass of floodplain fines may have been promoted by a basin parallel tilting component. It is shown that (i) cases in which the standard models fully apply, and (ii) cases in which differential subsidence is too strong or too abrupt, can be distinguished by analysing cross‐plots of cumulative‐sandstone and cumulative‐mudstone thickness.

Time-resolved detection of propagating Lamb waves in thin silicon membranes with frequencies up to 197 GHz

Guided acoustic waves are generated in nanopatterned silicon membranes with aluminum gratings by optical excitation with a femtosecond laser. The spatial modulation of the photoacoustic excitation leads to Lamb waves with wavelengths determined by the grating period. The excited Lamb waves are optically detected for different grating periods and at distances up to several μm between pump and probe spot. The measured frequencies are compared to the theoretical dispersion relation for Lamb waves in thin silicon membranes. Compared to surface acoustic waves in bulk silicon twice higher frequencies for Lamb waves (197 GHz with a 100 nm grating) are generated in a membrane at equal grating periods.

Centers with equal period functions

We give a sufficient condition for systems with symmetries to have periodic solutions with equal periods. We show that the main result can be applied both to Hamiltonian and to non-Hamiltonian systems. We apply the main results to produce planar centers with equal period functions.

REM sleep enhancement of probabilistic classification learning is sensitive to subsequent interference

During wakefulness the brain creates meaningful relationships between disparate stimuli in ways that escape conscious awareness. Processes active during sleep can strengthen these relationships, leading to more adaptive use of those stimuli when encountered during subsequent wake. Performance on the Weather Prediction Task (WPT), a well-studied measure of implicit probabilistic learning, has been shown to improve significantly following a night of sleep, with stronger initial learning predicting more nocturnal REM sleep. We investigated this relationship further, studying the effect on WPT performance of a daytime nap containing REM sleep. We also added an interference condition after the nap/wake period as an additional probe of memory strength. Our results show that a nap significantly boosts WPT performance, and that this improvement is correlated with the amount of REM sleep obtained during the nap. When interference training is introduced following the nap, however, this REM-sleep benefit vanishes. In contrast, following an equal period of wake, performance is both unchanged from training and unaffected by interference training. Thus, while the true probabilistic relationships between WPT stimuli are strengthened by sleep, these changes are selectively susceptible to the destructive effects of retroactive interference, at least in the short term.

Beneficial Effects of a Semi-Intensive Stroke Unit are Beyond the Monitor

Background and Purpose: Precise mechanisms underlying the effectiveness of the stroke unit (SU) are not fully established. Studies that compare monitored stroke units (semi-intensive type, SI-SU) versus an intensive care unit (ICU)-based mobile stroke team (MST-ICU) are lacking. Although inequalities in access to stroke unit care are globally improving, acute stroke patients may be admitted to Intensive Care Units for monitoring and followed by a mobile stroke team in hospital's lacking an SU with continuous cardiovascular monitoring. We aimed at comparing the stroke outcome between SI-SU and MST-ICU and hypothesized that the benefits of SI-SU are driven by additional elements other than cardiovascular monitoring, which is equally offered in both care systems. Methods: In a single-center setting, we compared the unfavorable outcomes (dependency and mortality) at 3 months in consecutive patients with ischemic stroke or spontaneous intracerebral hemorrhage admitted to a stroke unit with semi-intensive monitoring (SI-SU) to a cohort of stroke patients hospitalized in an ICU and followed by a mobile stroke team (MST-ICU) during an equal observation period of 27 months. Secondary objectives included comparing mortality and the proportion of patients with excellent outcomes (modified Rankin Score (mRS) 0-1). Equal cardiovascular monitoring was offered in patients admitted in both SI-SU and MST-ICU. Results: 458 patients were treated in the SI-SU and compared to the MST-ICU (n = 370) cohort. The proportion of death and dependency after 3 months was significantly improved for patients in the SI-SU compared to MST-ICU (p < 0.001; aOR = 0.45; 95% CI: 0.31-0.65). The shift analysis of the mRS distribution showed significant shift to the lower mRS in the SI-SU group, p < 0.001. The proportion of mortality in patients after 3 months also differed between the MST-ICU and the SI-SU (p < 0.05), but after adjusting for confounders this association was not significant (aOR = 0.59; 95% CI: 0.31-1.13). The proportion of patients with excellent outcome was higher in the SI-SU (59.4 vs. 44.9%, p < 0.001) but the relationship was no more significant after adjustment (aOR = 1.17; 95% CI: 0.87-1.5). Conclusions: Our study shows that moving from a stroke team in a monitored setting (ICU) to an organized stroke unit leads to a significant reduction in the 3 months unfavorable outcome in patients with an acute ischemic or hemorrhagic stroke. Cardiovascular monitoring is indispensable, but benefits of a semi-intensive Stroke Unit are driven by additional elements beyond intensive cardiovascular monitoring. This observation supports the ongoing development of Stroke Centers for efficient stroke care.

Sleep and Social Memory Consolidation

Event Abstract Back to Event Sleep and Social Memory Consolidation Amanda Santamaria1*, Owen Churches2, Alex Chatburn3, Hannah Keage1 and Mark Kohler1 1 University of South Australia, Cognitive Neuroscience Laboratory, Australia 2 Flinders University, Brain and Cognition Laboratory, Australia 3 University of South Australia, Centre for Sleep Research, Australia Social memory refers to the learning, consolidation and recall of social information that is crucial to interpersonal interaction. Face recognition is one feature of social interaction that can be investigated in a social memory paradigm. It is commonly recognized that active neurophysiological processes occurring during sleep aid learning and consolidation of information in general, yet little is known about whether sleep is important for learning and consolidation of social memories. The current study examines whether sleep facilitates recall of social stimuli in comparison to an equal period of time awake. Sixteen adults aged 19-29 years (14 female) took part in an experimental repeated measures design, which tested social memory performance immediately after learning and at two different delayed recall time points in both a sleep-first and wake-first condition. Sleep was quantified using polysomnography in both conditions. To test social memory performance, participants were asked to identify a set of learned target faces from a set of distractor faces. Overall memory performance scores decreased after periods of wake (F(1.44,21.58)=21.17, p<.001) but were maintained after immediate or delayed sleep periods (p=.22). As such, sleep was found to serve as a protective function for newly encoded social memories, rather than actively enhancing consolidation. Differences were also found between sleep-first and wake-first groups for correct identification of target faces, where the wake-first group missed more target faces(F(1,15)=6.75, p=.02). Even though sleep was found to be important to the consolidation of social memory and maintenance of social learning, no specific aspects of sleep architecture were associated with social memory performance. The results suggest that sleep acts as a protective factor against memory deterioration for social memories, however the precise neurophysiological characteristics of sleep important for this effect are yet to be determined. Keywords: Polysomnography, Sleep, EEG, faces, Social Memory, memory consolidation Conference: XII International Conference on Cognitive Neuroscience (ICON-XII), Brisbane, Queensland, Australia, 27 Jul - 31 Jul, 2014. Presentation Type: Poster Topic: Memory and Learning Citation: Santamaria A, Churches O, Chatburn A, Keage H and Kohler M (2015). Sleep and Social Memory Consolidation. Conference Abstract: XII International Conference on Cognitive Neuroscience (ICON-XII). doi: 10.3389/conf.fnhum.2015.217.00399 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 19 Feb 2015; Published Online: 24 Apr 2015. * Correspondence: Miss. Amanda Santamaria, University of South Australia, Cognitive Neuroscience Laboratory, Adelaide, Australia, amanda.santamaria@mymail.unisa.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Amanda Santamaria Owen Churches Alex Chatburn Hannah Keage Mark Kohler Google Amanda Santamaria Owen Churches Alex Chatburn Hannah Keage Mark Kohler Google Scholar Amanda Santamaria Owen Churches Alex Chatburn Hannah Keage Mark Kohler PubMed Amanda Santamaria Owen Churches Alex Chatburn Hannah Keage Mark Kohler Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

A Dedicated Research Program Increases the Quantity and Quality of Orthopaedic Resident Publications

Programs seek to expose trainees to research during residency. However, little is known in any formal sense regarding how to do this effectively, or whether these efforts result in more or better-quality research output. The objective of our study was to evaluate a dedicated resident research program in terms of the quantity and quality of resident research peer-reviewed publications. Specifically we asked: (1) Did residents mentored through a dedicated resident research program have more peer-reviewed publications in higher-impact journals with higher citation rates compared with residents who pursued research projects under a less structured approach? (2) Did this effect continue after graduation? In 2006, our department of orthopaedic surgery established a dedicated resident research program, which consisted of a new research policy and a research committee to monitor quality and compliance with this policy. Peer-reviewed publications (determined from PubMed) of residents who graduated 6 years before establishing the dedicated resident research program were compared with publications from an equal period of the research-program-directed residents. The data were assessed using descriptive statistics and regression analysis. Twenty-four residents graduated from 2001 to 2006 (before implementation of the dedicated resident research program); 27 graduated from 2007 to 2012 (after implementation of the dedicated resident research program). There were 74 eligible publications as defined by the study inclusion and exclusion criteria. Residents who trained after implementation of the dedicated resident research program published more papers during residency than did residents who trained before the program was implemented (1.15 versus 0.79 publications per resident; 95% CI [0.05,0.93]; p = 0.047) and the journal impact factor was greater in the group that had the research program (1.25 versus 0.55 per resident; 95% CI [0.2,1.18]; p = 0.005). There were no differences between postresidency publications by trainees who graduated with versus without the research program in the number of publications, citations, and average journal impact factor per resident. A regression analysis showed no difference in citation rates of the residents' published papers before and since implementation of the research program. Currently in the United States, there are no standard policies or requirements that dictate how research should be incorporated in orthopaedic surgery residency training programs. The results of our study suggest that implementation of a dedicated resident research program improves the quantity and to some extent quality of orthopaedic resident research publications, but this effect did not persist after graduation.

Trends and results in treatment of gastric cancer over last two decades at single East European centre: a cohort study.

BackgroundA steady decline in gastric cancer mortality rate over the last few decades is observed in Western Europe. However it is still not clear if this trend applies to Eastern Europe where high incidence rate of gastric cancer is observed.MethodsThis was a retrospective non-randomized, single center, cohort study. During the study period 557 consecutive patients diagnosed with gastric cancer in which curative operation was performed met the inclusion criteria. The study population was divided into two groups according to two equal time periods: 01-01-1994 – 31-12-2000 (Group I – 273 patients) and 01-01-2001 – 31-12-2007 (Group II – 284 patients). Primary (five-year survival rate) and secondary (postoperative complications, 30-day mortality rate and length of hospital stay) endpoints were evaluated and compared.ResultsRate of postoperative complications was similar between the groups, except for Grade III (Clavien-Dindo grading system for the classification of surgical complications) complications that were observed at significantly lower rates in Group II (26 (9.5%) vs. 11 (3.9%), p = 0.02). Length of hospital stay was significantly (p = 0.001) shorter (22.6 ± 28.9 vs. 16.2 ± 17.01 days) and 30-day mortality was significantly (p = 0.02) lower (15 (5.5%) vs. 4 (1.4%)) in Group II. Similar rates of gastric cancer related mortality were observed in both groups (92.3% vs. 90.7%). However survival analysis revealed significantly (p = 0.02) better overall 5-year survival rate in Group II (35.6%, 101 of 284) than in Group I (23.4%, 64 of 273). There was no difference in 5-year survival rate when comparing different TNM stages.ConclusionsGastric cancer treatment results remain poor despite decreasing early postoperative mortality rates, shortening hospital stay and improved overall survival over the time. Prognosis of treatment of gastric cancer depends mainly on the stage of the disease. Absence of screening programs and lack of clinical symptoms in early stages of gastric cancer lead to circumstances when most of the patients presenting with advanced stage of the disease can expect a median survival of less than 30 months even after surgery with curative intent.

A Single-Inductor, Multiple-Channel Current-Balancing LED Driver for Display Backlight Applications

A single-inductor boost light-emitting diode (LED) driver that can distribute equal dc currents to multiple channels of LEDs is presented. To ensure uniform brightness in display backlight units, the previous approaches used current regulation elements serially inserted in individual LED channels, which incur power losses. Instead, the proposed LED driver adopts a single-inductor-multiple-output boost converter topology, which keeps the channel currents equal in an open-loop fashion by connecting the current-delivering inductor to each channel for an equal period of time, in a time-division multiplexing manner. Furthermore, the sequence of conduction is continuously permutated in order to reduce possible systematic imbalances among the currents. A prototype LED driver demonstrates the peak power efficiency of 93.0% excluding the field-programmable gate array controller power and maximum current balance error of 2.04% while delivering 12.4 W to three channels of high-brightness white LEDs.