126 research outputs found

    Evaluation of olfactory bulbus volume and olfactory sulcus depth development with 3 Tesla MRI in childhood

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    Background: In this study, it is aimed to reveal the change in OBV and OSD in healthy Turkish pediatric individuals between 1 month and 18 years of age with 3 Tesla MRI taking into account different age groups and gender factors. Materials and methods: In this retrospective study, 190 pediatric individuals who underwent cranial MRI were evaluated. Healthy pediatric cases were divided into four groups as infantile period (first 24 months when cerebral myelinization was completed), early childhood (2-6 years), childhood (6-12 years) and adolescence (12-18 years). OBV and OSD measurements were performed on coronal T2-weighted brain MR images by 3T MR scan. The mean, right and left olfactory bulb volume and sulcus depths were used for evaluation. Results: The mean age was 9.9 ± 7.5 months for the infantile period, 4.5 ± 1.3 years for early childhood, 9.3 ± 1.7 years for childhood and 15.2 ± 1.7 years for adolescence. Mean, right and left OBV was found to be slightly larger in male children than female children (P= 0.015, P= 0.033 and P= 0.010, respectively). There was no statistical difference between the genders for mean, right and left OSD (P= 0.559, P= 0.536 and P= 0.598, respectively). Among the age groups, the values of the 3rd and 4th groups in terms of mean, right and left OBV were higher than the other two groups (P<0.001). In terms of OSD, mean, right and left values were higher in group 2, 3 and 4 than group one (P<0.001). Conclusions: These data differ by pediatric age group and gender for the development of OBV and OSD. Normal values for the pediatric age group and gender should be calculated to detect olfactory dysfunction

    On guarding real terrains: the terrain guarding and the blocking path problems

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    Locating a minimum number of guards on a terrain such that every point on the terrain is guarded by at least one of the guards is known as the Terrain Guarding Problem (TGP). In this paper, a realistic example of the terrain guarding problem is studied, involving the surveillance of a rugged geographical terrain by means of thermal cameras. A number of issues related to TGP are addressed with integer-programming models proposed to solve the problem. Also, a sensitivity analysis is carried out in which five fictitious terrains are created to see the effect of the resolution of the terrain, and of terrain characteristics, on coverage optimization and the required number of guards. Finally, a new problem, which is called the Blocking Path Problem (BPP), is introduced. BPP is about guarding a path on the terrain with a minimum number of guards such that the path blocks all possible infiltration routes. A discussion is provided about the relation of BPP to the Network Interdiction Problem (NIP), which has been studied extensively by the operations research community, and to the k-Barrier Coverage Problem, which has been studied under the Sensor Deployment Problem. BPP is solved via an integer-programming formulation based on a network paradigm

    Goos-H\"{a}nchen-like shifts for Dirac fermions in monolayer graphene barrier

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    We investigate the Goos-H\"{a}nchen-like shifts for Dirac fermions in transmission through a monolayer graphene barrier. The lateral shifts, as the functions of the barrier's width and the incidence angle, can be negative and positive in Klein tunneling and classical motion, respectively. Due to their relations to the transmission gap, the lateral shifts can be enhanced by the transmission resonances when the incidence angle is less than the critical angle for total reflection, while their magnitudes become only the order of Fermi wavelength when the incidence angle is larger than the critical angle. These tunable beam shifts can also be modulated by the height of potential barrier and the induced gap, which gives rise to the applications in graphene-based devices.Comment: 5 pages, 5 figure

    Video-Based Hand Movement Analysis of Parkinson Patients before and after Medication Using High-Frame-Rate Videos and MediaPipe

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    Tremor is one of the common symptoms of Parkinson’s disease (PD). Thanks to the recent evolution of digital technologies, monitoring of PD patients’ hand movements employing contactless methods gained momentum. Objective: We aimed to quantitatively assess hand movements in patients suffering from PD using the artificial intelligence (AI)-based hand-tracking technologies of MediaPipe. Method: High-frame-rate videos and accelerometer data were recorded from 11 PD patients, two of whom showed classical Parkinsonian-type tremor. In the OFF-state and 30 Minutes after taking their standard oral medication (ON-state), video recordings were obtained. First, we investigated the frequency and amplitude relationship between the video and accelerometer data. Then, we focused on quantifying the effect of taking standard oral treatments. Results: The data extracted from the video correlated well with the accelerometer-based measurement system. Our video-based approach identified the tremor frequency with a small error rate (mean absolute error 0.229 (±0.174) Hz) and an amplitude with a high correlation. The frequency and amplitude of the hand movement before and after medication in PD patients undergoing medication differ. PD Patients experienced a decrease in the mean value for frequency from 2.012 (±1.385) Hz to 1.526 (±1.007) Hz and in the mean value for amplitude from 8.167 (±15.687) a.u. to 4.033 (±5.671) a.u. Conclusions: Our work achieved an automatic estimation of the movement frequency, including the tremor frequency with a low error rate, and to the best of our knowledge, this is the first paper that presents automated tremor analysis before/after medication in PD, in particular using high-frame-rate video data

    Reply to Elmendorf and Ettinger: Photoperiod playsa dominantand irreplaceable role in triggering secondary growth resumption

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    In their Letter, Elmendorf and Ettinger (1) question the dominant role of photoperiod in driving secondary growth resumption (hereafter referred to as xylem formation onset) of the Northern Hemisphere conifers, recently reported by Huang et al. (2). Their opinions are grounded on the following three aspects, including 1) the seasonality of the photoperiod, 2) the dependence of the predictor variables (e.g., photoperiod, forcing, and chilling) on the response variable (the date of onset of xylem formation, day of the year [DOY]), and 3) the limited value of the obtained models for interannual forecasting. We think they bring up an interesting issue that deserves further discussion and clarification. Photoperiod is acknowledged to regulate spring bud swelling while wood formation starts (3, 4). Although photoperiod seasonality occurs at each site, its influence is marginal in our study given that the analysis involved comparisons among sites across the Northern Hemisphere. Our conclusion that photoperiod plays a dominant role was built upon the combination of several coherent pieces of evidence, rather than “the crux of Huang et al….” as they pointed out. First, we clearly stated that model 2, which modeled DOY as a function of the mean annual temperature of the site (MAT), forcing, chilling, and soil moisture, was considered the best model in terms of parsimony according to minimum Akaike information criterion and Bayesian information criterion, rather than R2 as referred to in their Letter. Second, photoperiod interacted with MAT and can explain 61.7% of the variance of MAT alone (2). Therefore, we concluded that secondary growth resumption was driven primarily by MAT and photoperiod or by their interaction, which is challenging to be disentangled without experimental data, we agree. In terms of biological functioning, they play an ..

    IL-6 mediated JAK/STAT3 signaling pathway in cancer patients with cachexia

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    CONCLUSION: STAT3 may be considered as a therapeutic target for cachectic patients with gastric, lung and breast cancer. Furthermore, IL-6 mediates STAT3 activation in cachectic gastric and breast cancer patients (Tab. 5, Fig. 2, Ref. 62)

    Parameters affecting water-hammer wave attenuation, shape and timing. Part 2: Case studies

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    This two-part paper investigates parameters that may significantly affect water-hammer wave attenuation, shape and timing. Possible sources that may affect the waveform predicted by classical water-hammer theory include unsteady friction, cavitation (including column separation and trapped air pockets), a number of fluid–structure interaction effects, viscoelastic behaviour of the pipe-wall material, leakages and blockages. Part 1 of this two-part paper presents the mathematical tools needed to model these sources. Part 2 of the paper presents a number of case studies showing how these modelled sources affect pressure traces in a simple reservoir-pipeline-valve system. Each case study compares the obtained results with the standard (classical) water-hammer model, from which conclusions are drawn concerning the transient behaviour of real systems.Anton Bergant, Arris S. Tijsseling, John P. Vítkovský, Dídia I. C. Covas, Angus R. Simpson and Martin F. Lamber

    The Evaluation of Damage Mechanism of Unreinforced Masonry Buildings After Van (2011) and Elazig (2010) Earthquakes

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    On March 8th, 2010 Karakocan-Elazig earthquake of magnitude 6.0 occurred at a region where masonry and adobe construction is very common Karakocan-Elazig is located in a high seismicity region on Eastern Anatolian Fault System (EAFS). Due to the earthquake, 42 people were killed and 14'113 buildings were damaged. Another city, Van located at South east of Turkey is hit by earthquakes with M = 7.2 occurred on October 23rd, 2011 at 13:41 (local time), whose epicenter was about 16 km north of Van (Tabanli village) and M = 5.6 on November 9th, 2011 with an epicenter near the town of Edremit, south of Van and caused the loss of life and heavy damages. Both earthquakes killed 644 people and 2608 people were injured. Approximately 10'000 buildings were seriously damaged. There are many traditional types of structures existing in the region hit by earthquakes (both Van and Elazig). These buildings were built as adobe, unreinforced masonry or mixed type. These types of buildings are very common in rural areas (especially south and east) of Turkey because of easy workmanship and cheap construction cost. Many of those traditional type structures experienced serious damages. The use of masonry is very common in some of the world's most hazard-prone regions, such as in Latin America, Africa, the Indian subcontinent and other parts of Asia, the Middle East, and southern Europe. Based on damage and failure mechanism of those buildings, the parameters affecting the seismic performance of those traditional buildings are analyzed in this paper. The foundation type, soil conditions, production method of the masonry blocks, construction method, the geometry of the masonry walls, workmanship quality, existence of wooden beams, type of roof, mortar between adobe blocks are studied in order to understand the reason of damage for these types of buildings.WoSScopu
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