Effect of inaccurate small field output factors on brain SRS plans

External beam radiotherapy often includes the use of field sizes 3 × 3 cm2 or less, which can be defined as small fields. Dosimetry is a difficult, yet important part of the radiotherapy process. The dosimetry of small fields has additional challenges, which can lead to treatment inconsistencies if not done properly. Most important is the use of an appropriate detector, as well as the application of the necessary corrections. The International Atomic Energy Agency and the American Association of Physicists in Medicine provide the International Code of Practice (CoP) TRS-483 for the dosimetry of small static fields used in external MV photon beams. It gives guidelines on how to apply small-field correction factors for small field dosimetry. The purpose of this study was to evaluate the impact of inaccurate small-field output factors on clinical brain stereotactic radiosurgery plans with and without applying the small-field correction factors as suggested in the CoP. Small-field correction factors for a Varian TrueBeam linear accelerator were applied to uncorrected relative dose factors. Uncorrected and corrected clinical plans were created with two different beam configurations, 6 MV with a flattening filter (6 WFF) and 6 MV without a flattening filter (6 FFF). For the corrected plans, the planning target volume mean dose was 1.6 ± 0.9% lower with p < 0.001 for 6 WFF and 1.8 ± 1.5% lower with p < 0.001 for 6 FFF. For brainstem, a major organ at risk, the corrected plans had a dose that was 1.6 ± 0.9% lower with p = 0.03 for 6 WFF and 1.8 ± 1.5% lower with p = 0.10 for 6 FFF. This represents a systematic error that should and can be corrected.

COLOUR PERCEPTION OF LED POINT LIGHT SOURCES IN SCOTOPIC VISION

When stimuli are made sufficiently small, colour-normal individuals report a loss in hue perception, similar to tritanopia. This effect is referred to as small-field tritanopia. The interaction between small-field tritanopia and the rods working in scotopic vision has not been clarified. In this study, the problem is investigated by freely adjusting the hue, lightness, and saturation of the test stimulus to match the colour of the reference stimulus by observers. Three colours on the blackbody radiation trajectory with colour temperatures of 3500K, 5400K, and 11600K were used as reference colours. Each stimulus subtended a diameter of 6' and 10.8'. The 5400K and 11600K stimuli were distributed diagonally from the lower left to the upper right of each reference stimulus in the CIE 1976 u’v’ uniform chromaticity scale diagram. The distribution was similar to those of tritanopia. For the 3500K stimulus, the result did not show the influence of small-field tritanopia.

Reheating after inflation by supersymmetry breaking

We study reheating after the end of inflation in models where the inflaton is the superpartner of goldstino and is charged under a gauged U(1) R-symmetry. We consider two classes of models – one is small field characterized by an almost flat Kähler space, and the other large field characterized by a hyperbolic Kähler space SU(1, 1)/U(1), while in both cases the inflaton superpotential is linear due to the R-symmetry. The inflationary observables of our models fit within 2$$\sigma $$ σ CMB values. Upon coupling the inflaton sector to the (supersymmetric) Standard Model, we compute the MSSM parameters, mass spectrum, and decay modes of the inflaton, with the resulting reheating temperature around $$10^8$$ 10 8 GeV. We also find that both models can accommodate superheavy LSP dark matter, depending on the parameter choice.

Increasing crop richness and reducing field sizes provides higher yields

Working landscapes represent >60% of terrestrial landscapes and thus represent opportunities for biodiversity conservation outside of traditional protected areas. For long, biodiversity conservation and crop productivity have been seen as mutually exclusive options. Here, we use a unique dataset that includes annual monitoring of 12,300 permanent 25 ha-plots over two decades across Spain to assess how working landscapes are changing over time and how these changes affect their ability to ensure high yields. We find that win-win strategies that are good for biodiversity conservation can also lead to increasing crop yields. Specifically, we find that management practices that favor increasing biodiversity values such as maintaining small field sizes and high crop richness values at the landscape scale actually lead to the greatest yield values across 54 crops considered. Win-win scenarios for biodiversity conservation and crop productivity are thus possible, yet not as widespread as they could be.

Pengembangan Modul Elektronik Menulis Teks Tanggapan Berbasis LMS Moodle dengan Muatan Ekoliterasi untuk Kelas 9

This research purposed to produce a Moodle module based ecoliteracy for 9th grade. This study used five methods, (1) preliminary analysis, (2) product development, (3) expert validation and revision, (4) small-scale field trials and revision, and (5) large scale product trial. This research produces a Moodle module with ecoliteracy in its content and presentation which has been validated by material, media, and language expert with certain qualifications. This study result is suitable product that get validation score 87.5% for material, 92.5% for media, and 70.5% for language. The result from small field trials is 75%, and 87.5% for large field trials, the product declared as suitable to use. This study ecoliteracy in the module content is contained in its themes, learning objectivities, materials, exercise, and cases that students must responses. Ecoliteracy in the module presentation is include in text, images, audios, and videos.

Method of multiple scales in scalar field cosmology

In this work, the method of multiple scales is applied to analysis of cosmological dynamics. The method is used to construct solutions to the dynamic equations of the Universe filled with a scalar field in the Friedman-Robertson-Walker metric. A general scheme is described for choosing small dimensionless parameters of the expansion of model functions and applying the method itself to the equations of cosmological dynamics. Solutions are given that are constructed for two different types of a small parameter - a small field value and a small slow roll parameter.