MRI-only based radiotherapy treatment planning for the rat brain on a Small Animal Radiation Research Platform (SARRP)

Computed tomography (CT) is the standard imaging modality in radiation therapy treatment planning (RTP). However, magnetic resonance (MR) imaging provides superior soft tissue contrast, increasing the precision of target volume selection. We present MR-only based RTP for a rat brain on a small animal radiation research platform (SARRP) using probabilistic voxel classification with multiple MR sequences. Six rat heads were imaged, each with one CT and five MR sequences. The MR sequences were: T1-weighted, T2-weighted, zero-echo time (ZTE), and two ultra-short echo time sequences with 20 mu s (UTE1) and 2 ms (UTE2) echo times. CT data were manually segmented into air, soft tissue, and bone to obtain the RTP reference. Bias field corrected MR images were automatically segmented into the same tissue classes using a fuzzy c-means segmentation algorithm with multiple images as input. Similarities between segmented CT and automatic segmented MR (ASMR) images were evaluated using Dice coefficient. Three ASMR images with high similarity index were used for further RTP. Three beam arrangements were investigated. Dose distributions were compared by analysing dose volume histograms. The highest Dice coefficients were obtained for the ZTE-UTE2 combination and for the T1-UTE1-T2 combination when ZTE was unavailable. Both combinations, along with UTE1-UTE2, often used to generate ASMR images, were used for further RTP. Using 1 beam, MR based RTP underestimated the dose to be delivered to the target (range: 1.4%-7.6%). When more complex beam configurations were used, the calculated dose using the ZTE-UTE2 combination was the most accurate, with 0.7% deviation from CT, compared to 0.8% for T1-UTE1-T2 and 1.7% for UTE1-UTE2. The presented MR-only based workflow for RTP on a SARRP enables both accurate organ delineation and dose calculations using multiple MR sequences. This method can be useful in longitudinal studies where CT's cumulative radiation dose might contribute to the total dose

(Re)Examining the African Diaspora and Christianity

Only recently has Africana studies broken through the ceiling of the academic basement and garnered the attention deserved. “(Re)Examining the African Diaspora and Christianity”, rejects Occidental understandings and interpretations of African Traditional Religions (ATRs). For example, the “fact” ATR’s are polytheistic. The paper begins by setting the general context and events of the African Diaspora and Euro-Christian colonization efforts. Next, I focus in on the West African Yoruba tradition to demonstrate how and why ATRs have been able to remain vibrant even after 500 years of displacement. Then, I put to task the common academic notions of syncretism in order to determine if any such relationship exists between ATRs and Christianity. Following the discussion, I explore the Catholic colonies and Protestant colonies for permissive or restrictive environments and the impact on ATRs. I close the paper by briefly addressing the modern impacts and discussion of reparations

EDUCATION AS A SOLUTION TO COMBAT RISING CYBERCRIME RATES AGAINST CHILDREN AND TEENAGERS

Ninety seven percent (97%) of people between the ages of 3 and 18 are found to be users of technology and internet services daily. This number also correlates with rising cyber crime rates against people in this age bracket. It is found that people between 3 and 18 years old are found to be technologically savvy but often lack the knowledge of how to protect themselves in online environments. Researchers have suggested that cybersecurity awareness training is an effective method at combating common forms of cyberattack such as social engineering. Social engineering attacks are found to make up 98% of successful cyberattacks and it is crucial that users of these internet and technology services are knowledgeable in protecting themselves. Cybersecurity education materials are commonly found in enterprise and higher education environments, but there is a gap of available research that evaluates the effectiveness of this education in the K-12 environment. Therefore, this project evaluates the following research questions to help address the gap: (Q1) What affective methods to educate children and teenagers on cybersecurity concepts? (Q2) What are best practices for topic selection when it comes to cybersecurity education in the 3–18-year age range? (Q3) What are unique challenges that may be encountered when implementing this type of education nationwide? The research will discover the answers for the proposed research questions by analyzing existing literature and reviewing case studies of successful cybersecurity education in K-12 schools. The selected case studies went through an inclusion and exclusion criteria which required the following items to be present: publishing by a reputable journal or conference, contain empirical data in form of pre and post assessment, why the method of teaching was selected, and explain limitations. The findings and conclusions from the case studies are: (Q1) Students are receptive to learning cybersecurity principles via multiple teaching styles. The case studies displayed self-guided, collaborative, and traditional instruction methods and students were shown to improve greatly in post assessment results. (Q2) Best practices for selecting topics in the case studies was to utilize age-appropriate cybersecurity educational materials published by government agencies. A finding from this is that these materials are not readily available for educators and must be sought out as they are considered optional items. (Q3) Scaling of these type of cybersecurity workshops is difficult due to resource constraints faced by many schools found in lower income and rural districts. The availability of cybersecurity professionals and university campus’s willingness to host these camps is scarce and leaves this type of experience out of reach for many students. Areas of further study are researching methods on how to effectively scale this sort of education by utilizing a remote learning model and the creation of a standardized age-appropriate curriculum

Could representations influence strategy?

A central question in industrial marketing is whether the form in which the external environment of a firm is represented influences the marketing strategy. This influence has been studied generally through case study research, and quantitative evidence is limited. In response to this limitation, this paper reports on a quasi-experiment investigating whether market representations have a constructive aspect in business. Empirically, this study compares two types of ostensive and performative market representations—service focus and product differentiation—in order to test for influence exacted by industrial marketing on strategies. Results indicate that service focus is selected when market representations rely on agency in firms (i.e., performative), and product strategies are selected when structures are emphasized (i.e., ostensive). This paper contributes to methodology development by expanding the link between a case study approach and quasi-experiments explaining how quasi-experiments can replicate findings in industrial marketing.peerReviewe

A push-pull unsymmetrical subphthalocyanine dimer

Unsymmetrical subphthalocyanine fused dimers have been prepared from appropriate ortho-dinitrile SubPc precursors. In particular, either electron-donating or electron-accepting substituents have been introduced on each SubPc constituent unit, resulting in unprecedented push–pull π-extended curved aromatic macrocycles. From fluorescence experiments in solvents of different polarity we conclude a dual fluorescence, namely a delocalized singlet excited state (1.73 eV) and a polarized charge transfer state (<1.7 eV). Pump probe experiments corroborate the dual nature of the fluorescence. On one hand, the delocalized singlet excited state gives rise to a several nanosecond lasting intersystem crossing yielding the corresponding triplet excited state. On the other hand, the polarized charge transfer state deactivates within a few picosesonds. Visualization of the charge transfer state was accomplished by means of molecular modeling with a slight polarization of the HOMO towards the electron donor and of the LUMO towards the electron acceptor

The Abundance of Soil Microbes in Relationship to Proximity to the Urban Area of Lancer Park in Farmville, Virginia

Soil microbes are microorganisms found in soil that serve various critical roles and functions in the environment, such as decomposition and the cycling of nutrients in ecosystems. Natural and human-caused factors can have positive and/or negative impacts on soil microbes. The objective of this study is to examine the abundance of soil microbes in relationship to proximity to the urban area of Lancer Park in Farmville, Virginia. Soil samples were taken from four locations within Lancer Park: the upper and lower floodplain of Buffalo Creek, the bottom of a large stormwater detention pond, and adjacent to an ephemeral channel connecting two stormwater retention areas. Soil samples were extracted with a soil corer, air-dried for 48 hours, and placed in airtight jars. Sensors recorded carbon dioxide concentrations every 3 seconds for at least four hours, which were then used to compute microbial biomass. The hypothesis of this study is that locations that are closer to Lancer Park will have a lower abundance of soil microbes compared to locations that are further away from Lancer Park

Sustainability in the automotive industry

Die Nachhaltigkeit gewinnt zunehmend an Bedeutung. Die vorliegende Arbeit befasst sich mit dem Thema der Nachhaltigkeit in der Automobilbranche. Dabei werden alle drei Perspektiven der Nachhaltigkeit anhand von Beispielen der Automobilbanche dargestellt. So wird verdeutlicht, wie dieses sensible Thema angewendet und umgesetzt wird

Jet-related Excitation of the [CII] Emission in the Active Galaxy NGC 4258 with SOFIA

We detect widespread [CII]157.7um emission from the inner 5 kpc of the active galaxy NGC 4258 with the SOFIA integral field spectrometer FIFI-LS. The emission is found associated with warm H2, distributed along and beyond the end of southern jet, in a zone known to contain shock-excited optical filaments. It is also associated with soft X-ray hot-spots, which are the counterparts of the `anomalous radio arms' of NGC~4258, and a 1 kpc-long filament on the minor axis of the galaxy which contains young star clusters. Palomar-CWI H-alpha integral field spectroscopy shows that the filament exhibits non-circular motions within NGC 4258. Many of the [CII] profiles are very broad, with the highest line width, 455 km/s, observed at the position of the southern jet bow-shock. Abnormally high ratios of L([CII])/L(FIR) and L([CII])/L(PAH7.7um) are found along and beyond the southern jet and in the X-ray hotspots. These are the same regions that exhibit unusually large intrinsic [CII] line widths. This suggests that the [CII] traces warm molecular gas in shocks and turbulence associated with the jet. We estimate that as much as 40% (3.8 x 10^39 erg/s) of the total [CII] luminosity from the inner 5 kpc of NGC 4258 arises in shocks and turbulence (< 1% bolometric luminosity from the active nucleus), the rest being consistent with [CII] excitation associated with star formation. We propose that the highly-inclined jet is colliding with, and being deflected around, dense irregularities in a thick disk, leading to significant energy dissipation over a wide area of the galaxy.Comment: Accepted for Publication in the Astrophysical Journal Oct 29 201

High order discretization of seismic waves-problems based upon DG-SE methods

International audienceHybrid meshes comprised of hexahedras and te-trahedras are particularly interesting for representing media with local complex geometrical features like the seabed in offshore applications. We develop a coupled finite element method for solving elasto-acoustic wave equations. It combines Discontinuous Galerkin (DG) finite elements for solving elastodynamics with spectral finite elements (SE) for solving the acoustic wave equation. SE method has demonstrated very good performances in 3D with hexahedral meshes and contributes to reduce the computational burden by having less discrete unknowns than DG. The implementation of the method is performed both in 2D and 3D and it turns out that the coupling contributes to reduce the computational costs significantly: for the same time step and the same elementary mesh size, the CPU time of the coupled method is almost halved when compared to the one of a full DG method