Half Of Field Research Articles

A Study of Brain Computer Interface Based on Steady State Visual Evoked Potentials for Left-and-Right Half Field Visual Stimulations

A Study of Brain Computer Interface Based on Steady State Visual Evoked Potentials for Left-and-Right Half Field Visual Stimulations

Effect of Ingestion Exposure of Selected Insecticides on Coccinella septempunctata and Harmonia axyridis (Coleoptera: Coccinellidae).

Simple SummaryIn chemical plant protection against pests it is very important to know the indirect effects of insecticides on non-target organisms. This research shows the indirect effects of two insecticides (thiacloprid and lambda-cyhalotrin as active substances) on two different species of ladybirds, i.e., native in Europe Coccinella septempunctata and alien invasive species Harmonia axyridis, which were fed with aphids previously intoxicated by an insecticide. The products tested killed most instars of both ladybird species within 3 h of the start of the ingestion of the intoxicated prey. The action of thiacloprid, to which the predators are exposed by the same route, was more extended in time in both the coccinellids, and more variable between their developmental instars. The applications of thiacloprid caused different responses in the two predator species, which is nevertheless variable across instars.The sensitivity to thiacloprid and lambda-cyhalothrin ingested from prey organisms was studied in Coccinella septempunctata and Harmonia axyridis, since the effect of ingestion exposure to these insecticides is unknown in these species. All developmental stages of the ladybirds were fed on Acyrthosiphon pisum treated with half or full field rate of the insecticides. Almost all instars were killed within 3 h of the start of ingestion of lambda-cyhalotrin-treated prey. The action of thiacloprid was more extended in time in both coccinellids and more variable between their instars. Reducing the field rate of lambda-cyhalothrin seems to have no practical value for the survival of either of the coccinellid species. Contrastingly, using half instead of the full field rate of thiacloprid may enhance the chances of survival in L1, L2, and L4 larvae of both species. Of all developmental stages tested, the survival dynamics of the adults of either species are closest to one another, whereas the apparent difference in the species response to the dose rate of thiacloprid was found in the L4 stage.

Innovative fluorescent probes for in vivo visualization of biomolecules in living Caenorhabditis elegans.

Caenorhabditis elegans (C. elegans) as a well-established multicellular model organism has been widely used in the biological field for half a century. Its numerous advantages including small body size, rapid life cycle, high-reproductive rate, well-defined anatomy, and conserved genome, has made C. elegans one of the most successful multicellular model organisms. Discoveries obtained from the C. elegans model have made great contributions to research fields such as development, aging, biophysics, immunology, and neuroscience. Because of its transparent body and giant cell size, C. elegans is also an ideal subject for high resolution and high-throughput optical imaging and analysis. During the past decade, great advances have been made to develop biomolecule-targeting techniques for noninvasive optical imaging. These novel technologies expanded the toolbox for qualitative and quantitative analysis of biomolecules in C. elegans. In this review, we summarize recently developed fluorescent probes or labeling techniques for visualizing biomolecules at the cellular, subcellular or molecular scale by using C. elegans as the major model organism or designed specifically for the applications in C. elegans. Combining the technological advantages of the C. elegans model with the novel fluorescent labeling techniques will provide new horizons for high-efficiency quantitative optical analysis in live organisms.

Critical Assessment of the Concepts and Misconceptions of the Cardiac Conduction System over the Last 100 Years: The Personal Quest of Robert H. Anderson.

Anatomical concepts regarding the conduction system of the heart have been a matter of debate since pioneering work done at the beginning of the 20th century. Robert H. Anderson was actively involved in this field for half a century. We aimed to investigate how his own concepts evolved over time. We have assessed anatomical concepts relating to the cardiac conduction system appearing since the key contributions made in the initial decade of the 20th century, analyzing them from the perspective of Robert H. Anderson, particularly focusing on the anatomical aspects of structures such as accessory atrioventricular pathways, including the so-called Mahaim-type fibers, connections between the atrioventricular node and the atrial myocardium, and so-called “specialized” internodal atrial tracts. To accomplish this task, we have taken as our starting point the initial concepts published in the first decade of the century, along with those subsequently reported up to 1976, and assessing them in the light of our most recently published works. The concepts put forward by Robert Anderson with regard to atrioventricular nodal bypass tracts, atrioventricular nodal inputs, decrementally conducting accessory pathways, and “tracts” for internodal atrial conduction, have remained consistent along the time frame of half a century.

Design aspects of large-aperture MODE lenses

Design aspects of multiple-order diffraction engineered surface (MODE) lenses are discussed that result in significant improvement of geometrical off-axis performance. A new type of aberration that is characteristic of this type of segmented lens, which is called zonal field shift, is minimized by curving front intercepts of zone transitions. Three MODE designs are compared, based on a 240 mm aperture, 1 m focal length system with a 0.125° half field angle over the astronomical R wavelength band (589 nm to 727 nm). Optimized curved-front designs indicate diffraction-limited monochromatic geometrical performance over the full field of view. A technique is implemented with a combination of a non-sequential ray-trace model and a diffraction code to model physical optical effects, which indicates that the modulation transfer function (MTF) of MODE lenses are significantly improved compared to a first-order equivalent refractive achromat.

Are half of the published papers in top-management-journals never cited? Refuting the myth and examining the reason for its creation

ABSTRACT A stylised fact in bibliometric research is that in the field of management studies, half or more of the papers published are never cited. If true, this implies that efforts and resources are considerably wasted because half of the academic work is not considered worthy by the same community that developed them. We studied a sample of 2777 papers published in 20 journals and representing different levels of quality. Of these, only 191 papers, representing 6.5% of the sample, were never cited, suggesting that the aforementioned stylised fact is a myth. We identified the factors that contribute to the level of citations, including the ranking of the journal in the quality list, time since last citation, and number of authors. The implications discussed suggest a need for reflection regarding the relevance of the factors that predict future citations.

Evaluating the performance of the visual half field paradigm as a screening tool to detect right hemispheric language dominance

ABSTRACT Language is among the most studied functional asymmetries, yet little is known about right hemispheric language dominance. Because of its low prevalence, including a big sample of individuals with this variant of brain organization implies testing large groups, which may not be feasible when using expensive techniques. One solution involves screening a large sample using a cost-efficient method and next inviting only those participants flagged as potentially right dominant for follow-up investigation. The behavioural visual half field paradigm has previously been validated and successfully applied in this manner. We report a large-scale visual half field screening performed in 315 left-handers to detect such individuals for subsequent MRI scanning. Of 38 cases selected as probably right language dominant based on a left visual half field advantage (>20 ms), 22 (58%) were confirmed by language fMRI to be rightward lateralized. This study also explored means to improve the predictive performance of the visual half field task. While we found its performance depended strongly on the chosen cut-off, overall, reaction time criteria resulted in higher true positive rates, while those based on accuracy led to superior positive predictive values. The most optimal strategy, however, may involve combining criteria considering both accuracy and reaction time.

POLARIMETRIC CALIBRATION OF THE SPACEBORNE DIRECTIONAL POLARIMETRIC CAMERA INSTALLED ON THE GF-5 SATELLITE

Abstract. The Spaceborne Directional Polarimetric Camera (SDPC) is dedicated to obtain an accurate information of clouds and microphysical properties of aerosol particles via multi-angle, multi-spectral and multi-polarization observations. It images the Earth with 110° field of view (FOV) in 3 polarimetric spectral bands and 5 non-polarimetric spectral bands from visible to near infrared. Due to its wide FOV telecentric optical system and multi-channels, polarization sensitivity of optical components (PSOC) and non-uniform response of pixels (NURP) are the main uncertainty factors of polarimetric calibration.In this paper, a polarimetric calibration model of SDPC has been constructed for increasing the measurement accuracy. Combined an integrating sphere with a polarization generator as source, PSOC can be measured in high accuracy by using the Fourier series analysis method which reduces the impact form the alignment error of the generator. The sectional viewing field measurement method is used to acquire NURP while the large aperture integrating sphere served as reference source. Subsequently, the data of NURP have been corrected by the relative transmittance of high frequency and low frequency respectively for polarized channels. The result of validation experiment shows that the polarization measurement errors in 0°, 15°, 30°, and 45° half field of view (HFOV) are all less than 0.5% when the degree of linear polarization of reference source is larger than 0.1.

Feasibility of proton FLASH irradiation using a synchrocyclotron for preclinical studies.

It has been recently shown that radiotherapy at ultrahigh dose rates (>40Gy/s, FLASH) has a potential advantage in sparing healthy organs compared to that at conventional dose rates. The purpose of this work is to show the feasibility of proton FLASH irradiation using a gantry-mounted synchrocyclotron as a first step toward implementing an experimental setup for preclinical studies. A clinical Mevion HYPERSCAN® synchrocyclotron was modified to deliver ultrahigh dose rates. Pulse widths of protons with 230MeV energy were manipulated from 1 to 20μs to deliver in conventional and ultrahigh dose rate. A boron carbide absorber was placed in the beam for range modulation. A Faraday cup was used to determine the number of protons per pulse at various dose rates. Dose rate was determined by the dose measured with a plane-parallel ionization chamber with respect to the actual delivery time. The integral depth dose (IDD) was measured with a Bragg ionization chamber. Monte Carlo simulation was performed in TOPAS as the secondary check for the measurements. Maximum protons charge per pulse, measured with the Faraday cup, was 54.6pC at 20μs pulse width. The measured IDD agreed well with the Monte Carlo simulation. The average dose rate measured using the ionization chamber showed 101Gy/s at the entrance and 216Gy/s at the Bragg peak with a full width at half maximum field size of 1.2cm. It is feasible to deliver protons at 100 and 200Gy/s average dose rate at the plateau and the Bragg peak, respectively, in a small~1cm2 field using a gantry-mounted synchrocyclotron.

The right visual field advantage for word processing is stronger in older adults

The human brain is functionally asymmetric. Producing and understanding language, for instance, engages the left hemisphere to a larger extent than the right in most people. Recent research showed that lateralization for auditory word processing increases with age. The present study extends these findings to the visual domain. We measured lateralization for visual word processing with the visual half field task in young (20–30 years) and older participants (70–80 years). The older cohort had a larger right visual field advantage in terms of reaction time (p = .016, dolder adults = 0.16, dyounger adults = 0.13) and accuracy (p = .053, dolder adults = 0.73, dyounger adults = 0.25). This difference was mainly driven by a weaker performance for words presented in the left visual field. Our findings suggest that hemisphere dominance for language increases with aging. Alternatively, the findings could be explained by delayed inter-hemispheric communication in older adults.

Cognitive processing of spatial relations in Euclidean diagrams

The cognitive processing of spatial relations in Euclidean diagrams is central to the diagram-based geometric practice of Euclid's Elements. In this study, we investigate this processing through two dichotomies among spatial relations—metric vs topological and exact vs co-exact—introduced by Manders in his seminal epistemological analysis of Euclid's geometric practice. To this end, we carried out a two-part experiment where participants were asked to judge spatial relations in Euclidean diagrams in a visual half field task design. In the first part, we tested whether the processing of metric vs topological relations yielded the same hemispheric specialization as the processing of coordinate vs categorical relations. In the second part, we investigated the specific performance patterns for the processing of five pairs of exact/co-exact relations, where stimuli for the co-exact relations were divided into three categories depending on their distance from the exact case. Regarding the processing of metric vs topological relations, hemispheric differences were found for only a few of the stimuli used, which may indicate that other processing mechanisms might be at play. Regarding the processing of exact vs co-exact relations, results show that the level of agreement among participants in judging co-exact relations decreases with the distance from the exact case, and this for the five pairs of exact/co-exact relations tested. The philosophical implications of these empirical findings for the epistemological analysis of Euclid's diagram-based geometric practice are spelled out and discussed.

The impact of the field width on VMAT plan quality and the assessment of half field method.

PurposeThe goal of this work is to investigate the field width dependence of the volumetric modulated arc therapy (VMAT) plan quality and to propose a half field method to irradiate large volumes effectively with VMAT.Materials and methodsWe compared four different VMAT methods; namely three full field (3ff), four full field (4ff), three half field (3hf), four half field (4hf). To evaluate the impact of the field width on VMAT plan quality, 12 different size PTVs were created in the virtual phantom and treatment plans generated for each PTV were compared. The effectiveness of our half field method was tested using computed tomography (CT) data of 10 nasopharyngeal carcinoma patients.ResultsIn the virtual phantom study, organs at risk (OAR) mean dose, the maximum point dose, and Homogeneity Index (HI) were found to be field width dependent. Conformation Number (CN) was not significantly affected. In the clinical study, 4hf plans obtained statistically significant dose reduction at brainstem (P < 0.001), right parotid (P = 0.034), oral cavity (P < 0.001), larynx (P = 0.003), cochlea (P = 0.017), lips (P = 0.024), and Body‐PTV (P = 0.04) compared to 4ff plans.ConclusionOur results indicate that VMAT plan quality is dependent on the field width. Half field VMAT method, with the help of reduced field width, shows a clear advantage for the irradiation of large size targets compared to traditionally used full field VMAT plans.

Optical design for the lens depth of a periscope-type 3 × zoom lens with 8-megapixel mobile phone

We present an optical design for the lens depth of a periscope-type 3 × zoom lens with 8-megapixel sensor in mobile phone. In the practice application, the lens depth of zoom lens must be less than the thickness of the mobile phone mechanism. The lens depth is thus the upper size limit of the prism thickness or the maximum surface aperture in the Y-direction of the zoom lens. The zoom lens in the designed system has an F-number of F/3.5 to F/5.5, a focal length of 4.514 mm to 13.442 mm, the half field angle in the x-direction is 23.96° to 8.488°, and the half field angle in the y-direction is 14.035° to 4.798°. The smallest lens depth of the zoom lens is 5.377 mm. These results show that the depth of a periscope-type zoom lens can be embedded in the mobile phone.

Design and optimization of optical receiving antenna based on compound parabolic concentrator for indoor visible light communication

An advanced optical receiving antenna based on compound parabolic concentrator (CPC) is proposed for indoor visible light communication (VLC). The design of the antenna is conducted into two parts. Firstly, the Taguchi methodology and ANOVA technique are utilized to explore and optimize structural parameters of receiving lens for improving the optical efficiency and matching the channel performance requirements in VLC system. Then, the indoor communication model is established, and the channel performance is analyzed by Matlab software. The results show that: the half field of view (FOV) of the lens can reach 50°, while the optical gain is 11.29. The received power is 6.7496 dBm, and the SNR is 84.9642 dB. The FOV increases by 66.67% when compared to the CPC. The SNR increases by 26.18% when compared with the case of receiving rays directly without any antenna, which is 2.13 times the CPC’s SNR increase. Thus, the optimally designed lens can ensure the high-speed and stable communication of the indoor VLC systems.

A three-dimensional manganese(II) coordination polymer: synthesis, structure and catecholase activity

A manganese-based coordination polymer, [Mn2L2(µ-MeOH)2]n (H2L = 2-hydroxy-1-naphthaldehyde isonicotinoylhydrazone) was obtained by self-assembly of 2-hydroxy-1-naphthaldehyde isonicotinoylhydrazone and manganese(II) acetate. The coordination polymer was characterized by IR, EPR and UV–Vis spectroscopy. The single-crystal X-ray diffraction study reveals that the dibasic tridentate ligand (L2−) is bound via ONO donor sites to manganese(II). Two such [ML] fragments are connected by µ2-bridged methanol (MeOH) to form a di-manganese species. The sixth site of each of the manganese is occupied by the pyridyl N atom of the isonicotinoyl group. This arrangement gives a polynuclear complex of the formula [Mn2L2(µ-MeOH)2]n. The coordination geometry of manganese is distorted octahedral. The X-band electron paramagnetic resonance (EPR) measurement of the complex at 77 K shows a six-line spectrum and a signal at the half field, with g = 4.88. The half-field signal indicates the dimeric nature of the complex in the solution state. The cyclic voltammetric measurement of the complex shows a reversible MnIII/MnII redox couple. The complex catalyzes the conversion of 3,5-di-tert-butyl catechol to the corresponding o-quinone with a catalytic turnover rate of (kcat) 27.22 h−1.

SciFi detector and associated method for real-time determination of profile and output factor for small fields in stereotactic radiotherapy.

PurposeFor determining small‐field profile and output factor during stereotactic radiotherapy quality assurance (QA) procedures, we propose a novel system based on the scintillating fiber (SciFi) detector with output image acquisition and processing to allow real‐time monitoring of profile and output factor.Materials and methodsThe employed detector is a SciFi detector made of tissue‐equivalent scintillating plastic fibers arranged in 6‐layer fiber ribbons with a fiber pitch of 275 μm in each layer. The scintillating signal at the detector output is acquired by a sCMOS (scientific complementary metal–oxide–semiconductor) camera and represents the projected field profile along the fibers axis. An iterative reconstruction method of the field from its projected profile based on a priori knowledge of some features of the radiation field defined by the stereotactic cones is suggested. The detector with implemented data processing has been tested in clinical conditions, for determining beam profiles and output factors, using cone collimators of different sizes from 4 to 15 mm diameter. The detector under test was placed at 1.4 cm depth and 98.6 cm source to surface distance (SSD) in a water‐equivalent phantom and irradiated by a 6 MV photon beam.ResultsThe reconstructed field profiles obtained from the detector are coherent with data from EBT3 radiochromic films, with differences within ±0.32 mm for both the FWHM and the penumbra region. For real‐time determination of the field output factor, the measured data are also in good agreement with data independently determined by the French Institute for Radiological Protection and Nuclear Safety (IRSN) based on radiochromic films and thermoluminescent 1 × 1 mm2 micro‐cubes dosimeters (TLD). The differences are within ±1.6% for all the tested cone sizes.ConclusionsWe propose and have tested a SciFi plastic scintillating detector with an optimized signal processing method to characterize small fields defined by cone collimators. It allows the determination of key field parameters such as full width at half maximum (FWHM) and field output factors. The results are consistent with those independently measured using TLD and radiochromic films. As the SciFi detector does not require a correction factor, it is in line with the International Atomic Energy Agency (IAEA) and the American Association of Physicists in Medicine (AAPM) TRS‐483 recommendations, and can be suitable for online QA of small radiation fields used in photon beam radiotherapy, and is compatible with MRI‐LINAC.

Laterality for recognizing written words and faces in the fusiform gyrus covaries with language dominance

Recognizing words and faces engages highly specialized sites within the middle fusiform gyrus, known as the visual word form area (VWFA) and fusiform face area (FFA) respectively. The VWFA and FFA have clear but opposite population-level asymmetries, with the VWFA typically being lateralized to the left and the FFA to the right hemisphere. The present study investigates how language dominance may relate to these asymmetries. We hypothesize that individuals with left hemisphere dominance for word production (i.e., left language dominance, LLD) will have typical lateralization for word and face recognition in the fusiform gyrus, whereas participants with right language dominance (RLD) will demonstrate ‘atypical’ rightward laterality for words and leftward dominance for faces. To test this hypothesis, we recruited twenty-seven left-handers who had previously been identified as being LLD or RLD based on a visual half field task. Using fMRI, hemisphere dominance was determined for language (Broca's region) as well as for word and face recognition in the middle fusiform gyrus for each participant. The direction of asymmetry correlated significantly between language and recognizing words (ρ = .648, p < .001) as well as between language and face recognition (ρ = −.620, p = .001). Moreover, most LLD-participants were typically lateralized for faces and written words, while both functions tended to be reversed in individuals with RLD. However, segregation between language and face recognition was less clear in participants with RLD, as many of them lacked an obvious asymmetry for faces. Although our results thus suggest there is no one-on-one relationship between asymmetries for language, written word and face recognition, they also argue against a complete independence of their lateralization.

New applications of the polynomial method: The cap set conjecture and beyond

The cap set problem asks how large can a subset of ( Z / 3 Z ) n (\mathbb {Z}/3\mathbb {Z})^n be and contain no lines or, more generally, how can large a subset of ( Z / p Z ) n (\mathbb {Z}/p\mathbb {Z})^n be and contain no arithmetic progressions. This problem was motivated by deep questions about structure in the prime numbers, the geometry of lattice points, and the design of statistical experiments. In 2016, Croot, Lev, and Pach solved the analogous problem in ( Z / 4 Z ) n (\mathbb {Z}/4\mathbb {Z})^n , showing that the largest set without arithmetic progressions had size at most c n c^n for some c &gt; 4 c &gt; 4 . Their proof was as elegant as it was unexpected, being a departure from the tried and true methods of Fourier analysis that had dominated the field for half a century. Shortly thereafter, Ellenberg and Gijswijt leveraged their method to resolve the original cap set problem. This expository article covers the history and motivation for the cap set problem and some of the many applications of the technique: from removing triangles from graphs, to rigidity of matrices, and to algorithms for matrix multiplication. The latter application turns out to give back to the original problem, sharpening our understanding of the techniques involved and of what is needed for showing that the current bounds are tight. Most of our exposition assumes only familiarity with basic linear algebra, polynomials, and the integers modulo N N .

Infrared Radiometry as a Tool for Early Water Deficit Detection: Insights into Its Use for Establishing Irrigation Calendars for Potatoes Under Humid Conditions

Low radiation is one of the most important factors which limits potential yield in potato. Under humid conditions, the dominance of diffuse radiation not only imposes challenges for radiation use efficiency in crops but also limits the water status surveillance through non-invasive methods like infrared radiometry. This study was carried out in the humid desert of the Peruvian central coast with the aim to relate maximum stomatal conductance (gs_max, an important water status indicator) with leaf and air temperature (dT) and crop water stress index (CWSI). In a potted trial, gs_max vs. dT were compared along the day in well-irrigated (field capacity) and water restricted (half field capacity) plants. In an additional field experiment, CWSI was validated by testing two irrigation timing treatments with pre-established gs_max threshold (0.15 [T1] and 0.50 [T2] mol H2O m−2 s−1) against a control (frequently irrigated). An acute stomatal closure sensitivity was detected which drove a gs_max fall (gs↓) near the solar noon. The intense stomatal closure caused a dT rise which showed positive higher values (> 2 °C) after gs↓. The significant yield reduction of T1 in relation to the control (− 38.2 ± 10.7%) highlighted that gs_max values > 0.15 must be used to warrant a high potato yield. These findings support the use of CWSI values ≤ 0.3–0.4 as thresholds for an appropriate irrigation in potatoes with assessments taken at around 15:00 hours, time in which plants have accumulated enough radiation allowing an appropriate detection of thermal emission under humid conditions.

EP-1933: Half field VMAT for MLC leakage reduction and dosimetric impact in whole pelvis radiotherapy

EP-1933: Half field VMAT for MLC leakage reduction and dosimetric impact in whole pelvis radiotherapy