Black Bars Research Articles

The impact of partially covered faces on trust attribution, sharing resources, and perceived fairness of one's own choices in Ultimatum Game.

Covered faces have been linked with impaired emotion recognition; yet, it is entirely unexplored how an occlusion due to face masks may affect individuals' behaviour in economic decisions. Across two studies, we explored whether partially covered faces (due to mask wearing or a horizontal black bar) and emotion displayed by the responder influence peoples' sharing behaviour in the Ultimatum Game and the perceived fairness of one's proposal.Study 1 showed participants were more willing to equally share their resources with a happy face (compared to a neutral one). In addition, they were more willing to make a fair proposal when the person displayed was not wearing a face mask. Our results also provide evidence that, when people had to judge how fair their proposal was, participants rated a fair proposal as fairer when responders showed happy faces without masks, while unfair proposals were rated as fairer with happy masked faces; similarly, angry faces led to fairer ratings for fair offers without masks and unfair offers with masks. Study 2 partially confirmed previous results, highlighting how a simple occlusion on the face does not have a direct effect on the proposal but moderates the effect of the displayed emotions.These findings indicate that social interactions might be affected by face occlusion, especially when it is represented by a face mask. Indeed, people might judge the same behaviour in different ways based on the fact that their counterpart has a partially covered face.

The description of the first rock-dwelling species of butterfly lizard Leiolepis Cuvier, 1829 (Squamata, Agamidae) from the Khorat Plateau in northeastern Thailand.

A new species of rock-dwelling Leiolepis is described from the Khorat Plateau in northeastern Thailand. Leiolepisglaurung sp. nov. can be differentiated from all other sexual species of Leiolepis by a combination of having a black gular region with a wide medial yellow stripe, a yellow ventrum with black mottling, bright red to orange subcaudal coloration, having reduced to no expandable flanks, and having only one black transverse bar on the flanks. This is the first rocky habitat-adapted Leiolepis. Leiolepisglaurung sp. nov. demonstrates numerous ecological adaptations to survive in these rocky habitats. Leiolepis are known for their expandable flanks with bright display colors, however Leiolepisglaurung sp. nov. has reduced or no ability to expand its flanks. We hypothesize this is an adaptation to reduce their body diameter to better fit into smaller rocky burrows unlike the larger and deeper burrows constructed in looser soils by other Leiolepis species. This discovery increases the number of Leiolepis species in Thailand to six, and worldwide to 11.

Oxynoemacheilus fatmae, a new species from the Güzelhisar Stream in the Aegean Sea basin, Türkiye (Teleostei: Nemacheilidae).

Oxynoemacheilus fatmae, a new species, is found in the Güzelhisar Stream in the northern Aegean Sea basin. It is differentiated from all other species of Oxynoemacheilus in the northern Aegean Sea and adjacent basins by having four to eight irregularly shaped narrow black bars on the posterior part of flank, and anterior parts of the flank with a marbled pattern. O. fatmae is differentiated from the closest species Oxynoemacheilus theophilii by having 14 fixed diagnostic nucleotide substitution sites, and the pair-wise genetic distance is 2.22%. It further differs from O. theophilii by having a slenderer body (body at dorsal-fin origin: 15%-17% standard length [SL] vs. 17%-18%), a slenderer caudal peduncle (10%-12% SL vs. 12%-13%), a more forked caudal fin (length of middle caudal-fin lope: 16%-19% SL vs. 19%-23%), and the absence the dorsal and ventral adipose crests on the caudal peduncle behind the vertical of the posterior anal-fin base (vs. present). Three species delimitation tests (assemble species by automatic partitioning (ASAP), automatic barcode gap discovery (ABGD) and generalized mixed yule-coalescent (GMYC)) and phylogenetic analyses reinforce the validity of O. fatmae as a distinct species.

Bayesian analysis on missing visual information and object complexity on visual search for object orientation and object identity.

Missing visual information, such as a gap between an object or an occluded view, has been shown to disrupt visual search and make amodal completion inefficient. Previous research, using simple black bars as stimuli, failed to show a pop-out effect (flat search slope across increasing visual set sizes) during a feature search when the target was partially occluded, but not in cases where it was fully visible. We wanted to see if this lack of a pop-out effect during feature (orientation) search extended to complex objects (Experiment 1) and identity search (Experiment 2). Participants completed orientation and identity visual search tasks by deciding whether the target was present or not present. Bayesian analyses was conducted to find evidence for observed data to be under the null (pop-out effects) or alternative hypotheses (differences in search slopes). When no occluders or gaps were present, a pop-out effect occurred when searching for a simple objects' orientation or identity. In addition, object complexity affected identity search, with anecdotal evidence suggesting that some complex object may not show a pop-out effect. Furthermore, white occluding bars were more disruptive than having a gap of visual information for feature search but not for identity search. Overall, pop-out effects do occur for simple objects, but when the task is more difficult, search for real-world objects is greatly affected by any type of visual disruption.

Problems and Handling Methods of Laser Printers

A laser printer is a common office and personal printing equipment widely welcomed for high-speed, high-quality print output. The high temperature usually causes the printer nozzle temperature to be too high, affecting the printing quality and even damaging the printer. This is because the laser printer works by attaching the toner to the paper through high-temperature sintering, hence the print head’s temperature. Maintaining a suitable temperature environment is crucial for the normal operation and life of the laser printer. In addition, If the position and thickness of the black and white tendons change, it may affect the uneven distribution of the ink when printing, resulting in patches or blur of the printed image. In the printer’s cartridges, the black and white bars are separated, ensuring that the ink in the cartridge is evenly distributed when printing. If the position and thickness of the black and white tendons change, it may affect the uneven distribution of the ink when printing, resulting in patches or blur of the printed image. Therefore, when replacing ink cartridges or resetting or modifying some settings of the printer, be careful to be sure not to damage the printer. This study aims to solve the technical defects of laser printers, improve the level of printing technology, and improve the user experience.

Preference and Nutritional Content of Black Wheat Snack Bar with Hibiscus Flavor

The development of snack bar products using black wheat as the base ingredient and hibiscus flavoring is expected to yield new variations of snack bar products. This study aimed to: Determine the preference levels for the color, aroma, texture, and taste of black wheat snack bars with hibiscus flavor; 2 Determine the carbohydrate, fat, and fiber content of snack bars that are accepted by consumers. The research employed experimental methods, sensory evaluation, and laboratory testing. Three experimental designs were used, involving the addition of hibiscus powder at 5%, 10%, and 15% of the weight of black wheat flour. Data obtained from sensory evaluations were analyzed descriptively, while data from nutritional content test were compared with Recommended Dietary Allowances (RDAs). The research results indicated that the black wheat snack bar with 15% hibiscus powder addition was the most preferred product among the panelists, with 60% of panelists choosing this product. The nutritional content per 30g serving of the black wheat snack bar with hibiscus flavor included 21.9g of carbohydrates, 4.4g of fat, and 1.6g of fiber. Therefore, by consuming this snack bar, 7% of the RDA for carbohydrates, 7% of the RDA for fat, and 5% of the RDA for fiber can be met. In conclusion, this product can be recommended to individuals who want to maintain their health despite frequent snack consumption.

Multiparametric Flow Cytometry Based Quantification of the Marrow Hematopoietic Stem and Progenitor Compartment in Post Allogeneic Stem Cell Transplant Recipients with Poor Graft Function to Evaluate Hematopoietic Stem Cell Quality and Predict Clinical Outcomes: A Pilot Study

Poor graft function (PGF) is a poorly defined, commonly occurring (estimated 5 to 27%) 1 and difficult to treat complication of allogeneic stem cell transplantation (Allo-HSCT). Thrombopoietin agonists such as eltrombopag (EPAG) or CD34-selected cell infusions are treatments offered for persistent cytopenias. However, with limited knowledge of pathophysiology, there is a lack of reliable prognostic biomarkers. We aimed to investigate if assessment of the BM hematopoietic stem and progenitor cell (HSPC) landscape by multiparametric flow cytometry (MP-FCM) could help evaluate stem cell quality and predict clinical outcomes in PGF patients. We screened the UHN biobank repository to identify banked BM samples of patients who underwent diagnostic BM aspirate for PGF post allo-HSCT. Patients who had progressive cytopenia in one or more lineages after achieving engraftment while having full donor chimerism were included. Relapse as a cause of cytopenia was excluded. Controls in 1:1 ratio were Allo-SCT recipients with stable counts with banked day 60 BM aspirate. The blinded BM samples were analyzed with a 14-parameter FCM adapted from panels previously utilized to assess HSPC and mature lineages in cord blood xenograft studies (2). We selected 12 each of PGF and controls. The mean age of all recipients was 50 years and donors was 30.5 years. 23/24 cases had AlloSCT for hematological malignancies with 15 having AML or MDS. There were 14 unrelated (9 matched, 5 mismatched) and 10 related (5 matched sibling, 5 haploidentical) donors. Mean cell dose of infused graft was 6.66(± 1.98)x 10E6/kg CD34 cells. The significant difference between PGF and controls were recipient age (median 57y vs 28y), allo-SCT number (3 vs 0 with 2 nd transplant), intensity of conditioning regimen (myeloablative in 16% PGF vs 83% controls), and incidence of ≥ grade 3 acute graft vs host disease (GVHD) (n=3 vs 0). Most common causes of PGF were GVHD (n=6), infections (n=4) and drug effects (n=5). 11 PGF patients were treated with EPAG with 5 patients (A3, B2, B3, B5, C4) showing complete response, 3 (A6, B6, C5) showing partial response, and 3 (A2, A4, C9) showing no response. Patient C1 showed complete recovery without the use of EPAG, while C9, who initially did not respond to EPAG, showed a slow spontaneous recovery almost a year later. Amongst non-responders A2 and A4 received CD34 boost; with A4 showing a good response to the second boost. Analyzing the HSPC population by MP-FCM, we found that the PGF vs control groups show significant differences in the percentage of CD34+CD19+ B-Lymphoid precursors (B-LP) and CD19+ B lymphocytes. The mean ± SD percentage of B Lymphocytes and B-LPs in the PGF cohort were 6.76% ± 0.096% and 0.39% ± 0.005% respectively, while in the control group they were 20.09% ± 0.136% and 1.17% ± 0.012% respectively. When the 50 th centile value of the B-LPs (0.375%) or CD19+ B cells (10.89%) was investigated as a cut off to predict the clinical syndrome, this strategy achieved a 75% success rate with 3 PGF (blue bars) or control (black bars) samples misclassified (Fig1). Next, we investigated if these HSPC fractions could help predict the clinical outcome of PGF cases. The cases A2 and A4 who demonstrated no count recovery and needed CD34 boost lie in the lower quartile of both B Lymphocytes as well as B Lymphoid precursors content (Fig 1 red arrows). Conversely the three PGF cases in the upper 50 centile of these cell populations (patient B3, C4 and C9) all showed either a spontaneous or EPAG induced recovery of counts. We further investigated if the proportion of immunophenotypic CD34+CD38-CD45RA-CD90+CD49f+ long-term HSC (LT-HSC) could provide additional prognostic information (Fig2). Again, patients A2 and A4 had LT-HSC in the lower 50 th centile. Patient C1 who showed a spontaneous recovery of counts without the need of EPAG had the highest proportion of LT-HSCs despite lying in the second quartile of the cohort for both B cells as well as B-LPs. In conclusion, MP-FCM based analysis of the HSPC landscape in PGF marrow could be a robust prognostic biomarker in Allo-SCT patients.

Detecting introgressive hybridization to maintain genetic integrity in endangered large waterbird: a case study in milky stork

Hybridization between milky stork (Mycteria cinerea) and painted stork (M. leucocephala) occurs frequently in captivity. Dusit Zoo is a captive breeding facility where storks with phenotypically ambiguous patterns have recently been observed, and their status remaining inconclusive. Here, we used a combination of phenotypic characters and genetic markers (cytochrome b and 14 microsatellite markers) to distinguish and identify hybrids from the two parental species (n = 114). Haplotype analysis revealed asymmetric mtDNA introgression from M. cinerea to M. leucocephala, with twelve morphologically classified M. leucocephala individuals carrying heterospecific mtDNA. Comprehensive biparental genetic assessments identified 33% of all three genetic clusters as admixed individuals, of which most were either F2 hybrids, backcrosses with M. leucocephala, or hybrids of unknown generation, implying weak premating isolation with the absence of intrinsic postzygotic isolation between parentals. Morphological analysis demonstrated that the absence or indistinctness of a black bar across the breast is the most noticeable trait to identify these hybrids. The endangered M. cinerea was found to have genomic contamination from M. leucocephala and vice versa, with at least 41 hybrid individuals being identified. These findings provide critical information for detecting hybrids and identifying suitable breeding stocks with genetic purity for future reintroduction and conservation management.

A new species of Parauchenoglanis (Auchenoglanididae: Siluriformes) from the Upper Lualaba River (Upper Congo), with further evidence of hidden species diversity within the genus.

Parauchenoglanis zebratus sp. nov. is a new species endemic to the Upper Lualaba in the Upper Congo Basin. It is distinguished from all its congeners known from the Congo Basin and adjacent basins by the presence of (1) distinctive dark-brown or black vertical bars on the lateral side of the body, at least for specimens about ≥120 mm LS , (2) a broad and triangular humeral process embedded under the skin and (3) a well-serrated pectoral-fin spine. Genetic analysis based on mtDNA COI sequences confirmed the genetic distinctiveness (2.8%-13.6% K2P genetic divergence) of P. zebratus sp. nov. from congeners within the Congo and adjacent river basins. The study also revealed additional undocumented diversity within P. ngamensis, P. pantherinus, P. punctatus and P. balayi, indicating the need for further in-depth alpha-taxonomic attention to provide more accurate species delimitations for this genus. The discovery of yet another new species endemic to the Upper Lualaba, and this well outside the currently established protected areas, highlights the critical need for further assessments to accurately document the species diversity to guide freshwater conservation prioritisation and biodiversity management in this region.

Empathising with masked targets: limited side effects of face masks on empathy for dynamic, context-rich stimuli

ABSTRACT Multiple studies revealed detrimental effects of face masks on communication, including reduced empathic accuracy and enhanced listening effort. Yet, extant research relied on artificial, decontextualised stimuli, which prevented assessing empathy under more ecologically valid conditions. In this preregistered online experiment (N = 272), we used film clips featuring targets reporting autobiographical events to address motivational mechanisms underlying face mask effects on cognitive (empathic accuracy) and emotional facets (emotional congruence, sympathy) of empathy. Surprisingly, targets whose faces were covered by a mask (or a black bar) elicited the same level of empathy motives (affiliation, cognitive effort), and accordingly, the same level of cognitive and emotional empathy compared to targets with uncovered faces. We only found a negative direct effect of face coverings on sympathy. Additional analyses revealed that older (compared to young) adults showed higher empathy, but age did not moderate face mask effects. Our findings speak against strong negative face mask effects on empathy when using dynamic, context-rich stimuli, yet support motivational mechanisms of empathy.

Cutaneous transcriptomic profiling and candidate pigment genes in the wild discus (Symphysodon spp.)

ABSTRACT Discus (Symphysodon spp.) is a popular freshwater ornamental fish with high market value due to its extraordinary skin pigmentation. The molecular mechanisms that govern skin colouration have yet to be identified. Six skin samples from wild discus were collected in the D1 (dorsal intense black bar stripe), D2 (ventral lighter bar stripes and orange carotenoid spots) and D3 (posterior without stripe nor spot) regions of wild discus for transcriptomic profiling and analysis. Differential analysis was conducted in 3 pair-wise comparisons, D1vsD3, D2vsD3 and D2vsD1. The results demonstrated that the melanin synthesis-associated genes (ERBB4, ADCY9, WNT2, 14-3-3 proteins and TSPAN genes) were upregulated in D1 and D2 regions, whereas carotenoids metabolism-associated genes (PLIN2, AHCY, RETSAT, STARD10, TTC39B and RDH1 genes) were uniquely expressed in D2 region. Amino acid metabolism-related pathways were enriched in both the D1 and D2 regions. MAPK pathway enrichment was detected merely in the D1 region, while various transporter activities were enriched in the D2 region. Further investigations speculated the key regulator roles of GNAQ, ADCY9, 14-3-3 and TSPAN genes in black vertical bar formation. This is the first fundamental report on discus skin pigment genes that could be extended into more detailed studies in the future.

The effect of modality onset asynchrony and processing time on the recognition of text-supplemented speech.

This study examined the effect of modality onset asynchrony and response processing time for the recognition of text-supplemented speech. Speech and text were periodically interrupted by noise or black bars, respectively, to preserve 50% of the sentence and presented in unimodal and multimodal conditions. Sentence recognition and response errors were assessed for responses made simultaneous with the stimulus or after its presentation. Increased processing time allowed for the cognitive repair of initial response errors in working memory. Text-supplemented speech was best recognized with minimal temporal asynchrony. Overall, text supplementation facilitated the recognition of degraded speech when provided sufficient processing time.

A new stream treefrog of the genus Hyloscirtus (Amphibia, Hylidae) from the Río Negro-Sopladora National Park, Ecuador.

Recent surveys in the Río Negro-Sopladora National Park revealed a striking new species of Hyloscirtus. The new species is easily diagnosed from all other congeners by its large body size (64.9 mm SVL in adult female); broad dermal fringes in fingers and toes; prepollex not projected into a prepollical spine and hidden under thenar tubercle; dorsum greyish-green, with paler-hued reticulum, yellow spots and black speckles; throat, venter, flanks and hidden surfaces of limbs golden-yellow with large black blotches and spots; fingers, toes and webbing yellow with black bars and spots; iris pale pink with black periphery. It is currently known only from its type locality, in the high montane forest on the southern slopes of the Cordillera Oriental of the Andes, southeastern Ecuador. The new species might be related to the H.larinopygion species group based on its morphology.

“Lucky Enough”: The Music and Stories That Make Vaughan's Lounge, New Orleans, Louisiana, United States

“Lucky Enough”: The Music and Stories That Make Vaughan's Lounge, New Orleans, Louisiana, United States

A Study Suggests Geosteers Often Are Missing the Target

Horizontal drilling makes it possible to drill through the most-productive rock, but based on the following charts, oil companies may often be missing that opportunity. The heavy black bars show the most-productive rock in two producing wells—one unconventional onshore and, the other, offshore and conventional. The tangle of thin, colored lines on and around it are the well paths chosen by 329 competitors in a geosteering contest showing that many of them got lost on the way. The charts are from a paper that analyzed 10,000 geosteering decisions made during the 2021 Rogii Geosteering World Cup, an annual competition started by the maker of geosteering software. The work by Rogii and a team of Norwegian researchers studying drilling decision making was presented at this year’s Unconventional Resources Technical Conference (URTeC 3722510). The results showed about half the contestants earned scores of 30% or less based on the percentage of the well in the target zone—weighted 75%—and their rate of penetration—25%. Only 14 of the 329 participants scored 60% or more, with the balance somewhere in between. To some extent, this dim view of geosteering is a product of the contest rules. Competitors were asked to geosteer two difficult wells at breakneck speed—a decision every 2 minutes based on data from the last 100 m drilled—with minimal information upfront about the wells chosen because they were difficult to steer. In the contest, there was no professional downside for poor performance. Still, it is the rare public attempt to measure how well drillers do at adjusting well plans to maintain contact with the most-productive rock. While the nature of the competition suggests it is not trying to replicate actual drilling conditions, it does raise questions about how well oil companies are doing at maximizing reservoir contact. They observed that some top performers in one well did poorly on the next, and luck played a significant role in some of the results. “The inconsistent performances of players in the two rounds/poor average scores/and significantly different well trajectories planned by geosteerers represent a lack of unified guidelines for stratigraphic-based steering,” Yasaman Cheraghi, a PhD fellow in computational engineering at the University of Stavanger, wrote in an email. Geography was not a good predictor of performance. While 40% of the participants were working in North America, where the greatest number of horizontal wells have been drilled, their results were not better despite their experience. Those involved in the geosteering simulations, based on wells in the Duverney shale in Western Canada and the Xihu Sub-Basin (Yuquan discovery) of the East China Sea, would say they were using a standard method—stratigraphic-based steering. That approach uses the data gathered while drilling and other data about the formation to predict how the layers of rock in the reservoir—the stratigraphy—are likely to change ahead of the steering.

I looked at you, you looked at me, I smiled at you, you smiled at me-The impact of eye contact on emotional mimicry.

Eye contact is an essential element of human interaction and direct eye gaze has been shown to have effects on a range of attentional and cognitive processes. Specifically, direct eye contact evokes a positive affective reaction. As such, it has been proposed that obstructed eye contact reduces emotional mimicry (i.e., the imitation of our counterpart’s emotions). So far, emotional mimicry research has used averted-gaze faces or unnaturally covered eyes (with black censor bars) to analyze the effect of eye contact on emotional mimicry. However, averted gaze can also signal disinterest/ disengagement and censor bars obscure eye-adjacent areas as well and hence impede emotion recognition. In the present study (N = 44), we used a more ecological valid approach by showing photos of actors who expressed either happiness, sadness, anger, or disgust while either wearing mirroring sunglasses that obstruct eye contact or clear glasses. The glasses covered only the direct eye region but not the brows, nose ridge, and cheeks. Our results confirm that participants were equally accurate in recognizing the emotions of their counterparts in both conditions (sunglasses vs. glasses). Further, in line with our hypotheses, participants felt closer to the targets and mimicked affiliative emotions more intensely when their counterparts wore glasses instead of sunglasses. For antagonistic emotions, we found the opposite pattern: Disgust mimicry, which was interpreted as an affective reaction rather than genuine mimicry, could be only found in the sunglasses condition. It may be that obstructed eye contact increased the negative impression of disgusted facial expressions and hence the negative feelings disgust faces evoked. The present study provides further evidence for the notion that eye contact is an important prerequisite for emotional mimicry and hence for smooth and satisfying social interactions.

Arbitrary extension of the antibubble lifetime

The lifetime of antibubbles - droplets separated from a liquid bath by a thin layer of air - has typically been too short for further study or application. We experimentally demonstrate a mechanical method for extending the antibubble lifetime from minutes to hours. The recorded longest lifetime is up to 13 hours. In our method, vertical vibrations stabilize the air film as successive shocks on the antibubble top compensate the upward air drainage. To suppress Faraday waves, the liquid surface is covered with bubbles. A theoretical model is built to obtain the threshold for a long-lived antibubble. In the figure, the black scale bar is 20mm and the blue one 2mm.

Synchronous monitoring of axial vibration and rotation speed of rotating cylinder by linear array scanning

The axial vibration (AV) and rotation speed (RS) signals of a rotating cylinder contain rich condition information. In order to harness such quantitative information, an effective measurement method for synchronous monitoring of the AV and RS is highly desirable. However, traditional approaches are restricted either by limited test distance or multiple isolated sensors, which makes the approaches impractical to synchronously acquire the AV and RS signals through a single device. In this paper, a generalized visual measurement method for synchronous monitoring of the AV and RS via linear array scanning (LAS) is proposed. The basic idea is to paste a mark containing a printed black continuous bar and a black block (BCBB) on the surface of a rotating cylinder, and use a linear array camera to synchronously sample the bar and blocks. For the extraction of mark edges, we propose a single edge pixel extraction method through gray gradient of row pixels based on the observation of relatively stable gray level distribution. Line scanned signals disturbed by seam error or axial offset are automatically corrected through seam compensation and axial offset correction respectively. Experimental validation of the proposed method is presented for the cylinder under static hammering, variable speed condition and steady speed condition at a scanning distance of 500 mm. Bilinear interpolation is applied to the scanned linear array images before extracting the edge features and helps improve measurement accuracy. Analyses in the time domain and frequency domain verify the effectiveness of the LAS. The average error between the RS signal obtained by LAS and the reference value is 0.1420 rpm. The correlation coefficient between the AV time-domain signal of LAS and the reference signal is up to 0.900 and the resonance frequency error in the frequency spectrum is less than 1 Hz.

P438: ARYL HYDROCARBON RECEPTOR SIGNALLING IN NORMAL HAEMATOPOIETIC (HSC) AND LEUKEMIA STEM CELLS (LSC): DIFFERENTIAL EFFECT OF AHR ANTAGONIST ON LSC COMPARED TO HSC

Background: Acute myeloid leukaemia (AML) is a devastating disease with poor prognosis. It is driven by leukemia stem cells (LSCs), which are able to survive treatment and drive relapse. This highlights the importance of characterizing LSCs. LSC-targeted treatment strategies are limited because there are no known surface markers that are specific for LSCs in every leukaemia. Targeting a signalling pathway that is altered in all LSCs could be a novel, promising treatment strategy. The aryl hydrocarbon receptor (AHR) pathway was shown to be critical for the self-renewal properties of normal haematopoietic stem cells (HSCs). Aims: We aimed to study the consequences of manipulating the AHR pathway in vivo in a murine leukaemia model. Methods: We used the following methods: murine bone marrow transplantation leukemia model (MBMTLM) - CALM-AF10 with limiting dilution assay (LDA); competitive repopulation assay (CRA) with LDA (CD45.2 donors into CD45.1 recipient mice), transcriptome analysis (sequencing with the Illumina platform and analisys with the DESeq2). Treatment of the cells was performed at various experiments with the AHR agonist, ITE, and an AHR antagonist, CH-223191 (a vehicle control is DMSO). Results: We used a murine retroviral transduction bone marrow transplantation leukemia model (MBMTLM)) with the CALM-AF10 minimal fusion gene (CAMF) as the oncogenic driver, to study the effect of AHR agonist (ITE) and an AHR antagonist (CH-223191) treatment on LSCs. Interestingly, both AHR agonist and antagonist treatment affected LSC frequency and survival of mice transplanted with treated cells. The LSC frequency as measured by limiting dilution transplantation assays (LDA) was 3.7 times lower after agonist treatment (1:163, blue survival curve in fig. 1, A) compared to a vehicle control (1:44, DMSO, black survival curve)). Very interestingly, after antagonist treatment the LSC frequency was so low that could not be measured as none of the mice transplanted with antagonist-treated cells in the LDAs developed leukaemia (n=9, CH-223191 (red curve in fig. 1, A)). Of note, our CAMF MBMTLM has a very high LSC frequency of about 1:4 in cells that were not cultured after thawing. We performed RNA-Seq on 90 samples to determine changes in gene expression patterns after treatment of healthy bone marrow cells and CAMF leukemia cells with the AHR agonist and antagonist. Preliminary differential expression analysis with DESeq2 revealed differential expression of genes involved in apoptosis and proliferation in leukaemia cells treated with CH-223191. As leukemia did not develop in recipients of cells treated with the antagonist CH-223191, genes differentially regulated in these cells might be critical and specific to LSC function and will be candidate targets for LSC-specific treatments. To confirm that AHR antagonist treatment affects LSCs differently than normal HCS, we performed competitive repopulation assay (CRA). Our preliminary data (n = 12) show that treatment of HSCs with CH-223191 results in a steady increase in the engraftment over a 47-week period following transplantation (coral bars, fig. 1, B), as opposed to the grafts from the ITE-treated arm (blue bars), vehicle or untreated HSCs (black and green bars, respectively). Image:Summary/Conclusion: In summary, our data show that the LSCs react differently than normal HSCs to changes in AHR signalling. These differences suggest it might be possible to specifically inhibit LSCs while sparing normal HSCs, thus paving the way to develop strategies to treat leukemia based on manipulating AHR signalling.

Abstract TP221: Hyperacute Anterior Circulation Stroke Due To Atherosclerotic Occlusion Still Have Risks Of Cardioembolism

Background and Purpose: The difference among anterior and posterior circulation stroke regarding vascular risk factors is commonly known. Our aim is to verify the difference of clinical backgrounds between anterior and posterior circulation in hyperacute stroke with large vessel occlusion (LVO) caused by atherosclerotic occlusion (AO). Methods: This multicenter, retrospective study included LVO patients who were performed revascularization therapy (thrombectomy, intravenous thrombolysis, or both) between October 2017 and May 2021. The definition of AO was the fixed residual stenosis/occlusion at the initially occluded lesion confirmed in the second angiographic imaging performed 7 days later from symptom onset. The patients were dichotomized by LVO location, anterior or posterior. Traditional risk factors and laboratory data were compared. Results: Among the 1770 consecutive stroke patients admitted during the study period, 162 patients (104 men, median age 76 years old) were enrolled in our study. AO was diagnosed in 41 patients (25%; 27% of anterior circulation vs. 17% of posterior, P=0.291). In total cohort, patients with anterior circulation showed higher frequency of atrial fibrillation, lower glycosylated hemoglobin level, higher D dimer level, and higher brain natriuretic peptide level (Figure 1 black bar). The cohort of AO patients had a similar tendency (Figure 1 blue bar). Conclusion: One fourth of patients with LVO are AO. In anterior circulation stroke with AO, attention should be paid to stroke recurrence due to not only atherosclerosis but embolism.