Search

A challenge for prospective teachers (PTs) is to determine what students know about a topic through asking appropriate questions and being thoughtful about the wording of these questions so as to capture and reframe students' spontaneous mathematical thinking and eventually unriddle the fuzzy boundary of students' complex thinking. This study examined four PTs' efforts to elicit kindergarteners' subtraction strategies and make conclusions about their subtraction understanding. Drawing on PTs' plans for interviewing kindergarteners on subtraction problems, interview transcripts, and reflection papers, the results suggest that PTs provided effective scaffolds, adding context to numerical problems or explaining mathematical terms and symbols as needed. However, they avoided asking problems with subtrahends greater than five, numbers above ten, and missing starts or missing subtrahends, limiting their ability to draw targeted conclusions about the students' strengths and needs. Using effective questions allowed one PT who posed a limited variety of problems to make stronger conclusions about her student's subtraction understanding, while asking a broader variety of problems helped another PT who used limited questions make conclusions about her student's subtraction understanding. Based on these results, mathematics teacher educators could leverage their PTs' strengths to either encourage multiple interviews, each targeting different problem types, or one interview with a broader variety of problem types. The results of this study further highlight the need for PTs to move beyond just asking students to explain their strategies and have them justify or represent their strategies as well.

Children with intellectual disabilities experience well-documented challenges in the development of problem-solving, particularly related to mathematical word-problem solving. Such challenges are related to both linguistic and conceptual skills. While interventions to assist children in developing conceptual skills are well reported, linguistic interventions within the mathematical field are limited. This study aimed to determine the effect of an augmented-input intervention, on subtraction word-problem solving for children with intellectual disabilities. A multiple baseline across behaviours design was used and replicated across the seven participants. Intervention was provided in three tiers (one week each) for change, combine, and compare subtraction word-problems. Intervention was withdrawn for a four week period and followed by a maintenance phase. Results suggested that for older participants with higher receptive language and numerical operation scores, the augmented-input intervention provided significant gains across all three types of word-problems. Overall, four of the seven participants showed improvement in subtraction word-problem solving. Augmented input may provide language supports for subtraction word-problem solving for some children with mild intellectual disability.

Background: Flow altering angiographic procedures suffer from ill‐defined, qualitative endpoints. Quantitative digital subtraction angiography (qDSA) is an emerging technology that aims to address this issue by providing intra‐procedural blood velocity measurements from time‐resolved, 2D angiograms. To date, qDSA has used 30 frame/s DSA imaging, which is associated with high radiation dose rate compared to clinical diagnostic DSA (up to 4 frame/s). Purpose: The purpose of this study is to demonstrate an interleaved x‐ray imaging method which decreases the radiation dose rate associated with high frame rate qDSA while simultaneously providing low frame rate diagnostic DSA images, enabling the acquisition of both datasets in a single image sequence with a single injection of contrast agent. Methods: Interleaved x‐ray imaging combines low radiation dose image frames acquired at a high rate with high radiation dose image frames acquired at a low rate. The feasibility of this approach was evaluated on an x‐ray system equipped with research prototype software for x‐ray tube control. qDSA blood velocity quantification was evaluated in a flow phantom study for two lower dose interleaving protocols (LD1: 3.7±0.02mGy/s$3.7 \pm 0.02\ {\mathrm{mGy}}/{\mathrm{s}}$ and LD2: 1.7±0.04mGy/s$1.7 \pm 0.04{\mathrm{\ mGy}}/{\mathrm{s}}$) and one conventional (full dose) protocol (11.4±0.04mGy/s)$11.4 \pm 0.04{\mathrm{\ mGy}}/{\mathrm{s}})$. Dose was measured at the interventional reference point. Fluid velocities ranging from 24 to 45 cm/s were investigated. Gold standard velocities were measured using an ultrasound flow probe. Linear regression and Bland‐Altman analysis were used to compare ultrasound and qDSA. Results: The LD1 and LD2 interleaved protocols resulted in dose rate reductions of −67.7% and −85.5%, compared to the full dose qDSA scan. For the full dose protocol, the Bland‐Altman limits of agreement (LOA) between qDSA and ultrasound velocities were [0.7, 6.7] cm/s with a mean difference of 3.7 cm/s. The LD1 interleaved protocol results were similar (LOA: [0.3, 6.9] cm/s, bias: 3.6 cm/s). The LD2 interleaved protocol resulted in slightly larger LOA: [−2.5, 5.5] cm/s with a decrease in the bias: 1.5 cm/s. Linear regression analysis showed a strong correlation between ultrasound and qDSA derived velocities using the LD1 protocol, with a R2${R}^2$ of 0.96$0.96$, a slope of 1.05$1.05$ and an offset of 1.9$1.9$ cm/s. Similar values were also found for the LD2 protocol, with a R2${R}^2$ of 0.93$0.93$, a slope of 0.98$0.98$ and an offset of 2.0$2.0$ cm/s. Conclusions: The interleaved method enables simultaneous acquisition of low‐dose high‐rate images for intra‐procedural blood velocity quantification (qDSA) and high‐dose low‐rate images for vessel morphology evaluation (diagnostic DSA). [ABSTRACT FROM AUTHOR]

Background: The main treatment of intermediate-stage hepatocellular carcinoma (HCC) is considered to be transcatheter arterial chemoembolization (TACE). Objective: To compare the accuracy of 3D reformatted computed tomography (CT) angiography and digital subtraction angiography (DSA) during TACE for the identification of feeding arteries of hepatocellular carcinoma. Patients and Methods: This prospective study was performed on 50 cases already diagnosed with HCC. Arterial phase multidetector-row CT (MDCT) images were retrospectively reformatted and analyzed to determine the anatomical variants of hepatic arterial supply and tumor-feeding vessel using maximum intensity projection (MIP), multi-planar reconstruction (MPR), and volume-rendering (VR) technique and compared to results of DSA done during TACE. Results: The whole number of HCC lesions was 68 lesions. The accuracy of CT angiography using MIP and VR techniques for assessing hepatic artery variations was (100%) in MIP and (94%) in VR technique compared to DSA done during TACE. The total number of feeding arteries was 96 feeder arteries; 93 feeders were from hepatic artery branches and only 3 feeders were extra-hepatic. The accuracy of assessing the feeding arteries of HCC was (87.5%) in MIP and (24%) in VR techniques compared to DSA results. Conclusions: For evaluating HCC feeding arteries, CT angiography with MIP demonstrated more accuracy and superior image quality than the VR technique compared with DSA done during TACE. [ABSTRACT FROM AUTHOR]

Successful math word-problem solving is difficult for some students. Getting the right answer involves students engaging correctly in an amalgamation of actions. Schema instruction is an instructional approach aimed at supporting students in identifying the underlying math problem structure to yield an appropriate solution plan. The focus of this article is on supporting educators in understanding the core ingredients of schema instruction and explaining how to implement it effectively with students with elementary grades emotional and behavioral disorders.

Background: Chin-on-chest deformity is a rare and severely disabling condition characterized by kyphotic deformity in the cervicothoracic spine. To treat this deformity, various osteotomy techniques were described. Methods: A comprehensive literature search of biomedical databases including MEDLINE (via PubMed), Scopus (via Elsevier), Embase (via Elsevier), and Cochrane Library in English from 1/1/1990 to 3/31/2022 was conducted using a combination of text and Medical Subject Headings (MeSH). Results: The final analysis included 16 studies. All the studies were assigned a level of evidence of four. Except for two articles, all of the articles were non-comparative studies. A total of 288 patients were included in this review. Of the 288 patients, 107 underwent posterior column extension osteotomy (PCEO), 108 underwent pedicle subtraction osteotomy (PSO), and 33 underwent vertebral column resection osteotomy (VCRO). The most common osteotomy level in fifteen of the studies was C7/T1. The studies included in this review described several techniques for cervical sagittal balance correction. The range of preoperative and postoperative visual analogue scale (VAS) scores was 5.5–8.6 to 1.7–4.91, respectively. The range of preoperative and postoperative neck disability index (NDI) was 34.2–65.4 to 22.1–51.3, respectively. The most common complications were upper extremity paresthesia and hand numbness through the C8 dermatome distribution. Conclusions: Corrective osteotomies provide satisfactory results in patients with chin-on-chest deformity; however, the quality of the included studies limits the evidence.

Abstract Background Advanced pancreatic adenocarcinoma lacks effective treatment options, and systemic gemcitabine-based chemotherapy offers only marginal survival benefits at the cost of significant toxicities and adverse events. New therapeutic options with better drug availability are warranted. This study aims to evaluate the safety and efficacy of digital subtraction angiography (DSA)-guided pancreatic arterial infusion (PAI) versus intravenous chemotherapy (IVC) using the gemcitabine and oxaliplatin (GEMOX) regimen in unresectable locally advanced or metastatic pancreatic cancer (PC) patients. Materials and methods This study prospectively enrolled 51 eligible treatment-naive patients with unresectable PC to receive GEMOX treatment via PAI or IVC (1:1 ratio randomization) from December 2015 to December 2019. Cycles were repeated monthly, and each process consisted of two treatments administered bi-weekly. Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), 1-year survival, 6-month survival, tumor-site subgroup survival, and incidences of adverse events were compared. Results The median OS of the PAI and IVC groups were 9.93 months and 10.07 months, respectively (p = 0.3049). The median PFS of the PAI and IVC groups were 5.07 months and 4.23 months (p = 0.1088). No significant differences were found in the ORR (11.54% vs. 4%, p = 0.6312), DCR (53.85% vs. 44%, p = 0.482), and 1-year OS rate (44% vs. 20.92%, p = 0.27) in PAI and IVC groups. The 6-month OS rate was significantly higher in the PAI group (100%) than in the IVC group (83.67%) (p = 0.0173). The median OS of patients in PAI group with pancreatic head and neck tumors were significantly higher than those of body and tail tumors (12.867 months vs. 9 months, p = 0.0214). The incidences of hematologic disorders, liver function disorders, and digestive disorders in the IVC group were higher than in the PAI group (p < 0.05). Conclusion GEMOX PAI therapy presented a higher 6-month OS rate and fewer adverse events than IVC in advanced pancreatic adenocarcinoma patients. Those with pancreatic head and neck tumors may yield a superior treatment outcome from PAI treatment. Trial registration number NCT02635971. Date of registration 21/12/2015.

Abstract We extend the local infrared-divergence subtraction formalism, originally proposed by Frixione, Kunszt and Signer (FKS), to calculate short-distance (differential) cross section for any inclusive process involving a quarkonium particle in non-relativistic QCD (NRQCD) factorisation at next-to-leading order (NLO) accuracy in the strong coupling constant α s . The new formulas are generally applicable to the production of an S- or P-wave quarkonium state in association with any number of elementary particles. The main new ingredients derived in this paper are the local and integrated soft counterterms for the colour-singlet and colour-octet P-wave bound states. It, therefore, paves the way to the automation of the NLO calculations for heavy quarkonium inclusive and associated production processes.

Elementary and middle school prospective teachers participated in semi-structured problem posing for integer addition and subtraction. The prospective teachers (n = 98) posed a variety of different stories, but this paper focuses on the temperature stories they posed. Results include descriptions of their posed temperature stories through the lens of the various dimensions (i.e., problem types, realism, consistency, correctness). Prospective teachers posed mainly state-translation-state problem types and rarely posed state-state-distance, state-state-translation, or translation-translation-translation problem types. They often changed the structure of their number sentences. Although they posed mostly realistic and mathematically correct temperature stories, the stories compromised realism or consistency in order to use state-translation-state problem types. Coordinating of the various dimensions (e.g., problem types, consistency) when problem posing requires flexibility with problem types. This work highlights the complexity of posing temperature stories, and coordinating the various dimensions highlights the need for prospective teachers to experience problem posing. Implications for problem posing with integers and temperature are extended to all contexts that inherently support translation and relativity. In the discussion, we coordinate the different problem types with various number sentences and dimensions. Unpacking the various dimensions illuminates prospective teachers' thinking and offers a way of considering integers and contexts.

Our aim is to explore the idea of neutrosophic N-ideals in near-subtraction semigroups in this article and obtain some outcomes that are equivalent to them. We also illustrate the notion of a neutrosophic κ-intersection. Additionally, in a near-subtraction semigroup, we examine the term homomorphism of a neutrosophic κ-structure and establish some conclusions based on a homomorphic neutrosophic κ-structure preimage of a neutrosophic κ-left (respectively, right) ideal.

Abstract Background Bone‐subtraction computed tomography angiography (CTA) (BSCTA) is a new technique designed to overcome the limitation of three‐dimensional CTA, where the vessels surrounded by bone and calcification can be obscured. An optimal contrast CT protocol for intracranial artery visualization with BSCTA has yet to be established in dogs. Objectives The purpose of this study was to determine the optimal contrast protocol of CTA for visualizing intracranial artery using an automatic bone‐subtraction technique in dogs. Methods Brain CTA was performed four times for each of nine healthy beagle dogs to cover all the contrast protocols: two different contrast iodine concentrations (300 and 370 mgI/mL) and two different contrast media injection rates (2 and 4 mL/s). Bone removal post‐processing was performed automatically by subtracting the non‐enhanced CT data from the contrast CT data using a dedicated workstation. The bone‐subtracted intracranial vessels were analysed for quantitative and qualitative evaluation. Results Quantitative evaluation showed significantly higher CT attenuation values for the group with a 370 mgI/mL iodine content at a rate of 4 mL/s than the two groups with a 300 mgI/mL iodine content at the rates of 2 and 4 mL/s (p

Objective To investigate the values of enhancing tumor volume (V), total volume (Vn) and relative non-enhancing tumor ratio (rNTR) before second-line treatment on overall survival (OS) and post-recurrence survival (PRS) in recurrent glioblastoma (rGBM). Methods Clinical data of 85 patients with confirmed rGBM admitted in our medical center from July 2012 to December 2022 were collected and retrospectively analyzed. Quantitative measurements of V, Vn (including tumor enhancement, necrotic and cystic volume) and rNTR (FLAIR high signal volume/enhancing tumor volume) were performed with T1-weighted imaging (T1WI) subtraction mode. Kaplan-Meier survival curve and log-rank test were used to analyze the differences of prognosis between high and low level groups of above indicators. Cox proportional risk regression model was employed for univariate and multivariate prognostic analyses. Results The median PRS was 238 d (95%CI: 197.472~278.528) and the median OS was 449 d (95%CI: 348.755~549.245) in these patients. Kaplan-Meier curve and log-rank test showed significant differences in PRS and OS between high and low levels groups of V, Vn and rNTR (P < 0.05). Univariate analysis showed that V, Vn and rNTR were all influencing factors for PRS and OS (P < 0.05). Multivariate analysis indicated that V and Vn were independent risk factors for PRS (HR=1.019, P < 0.001), and Vn was an independent risk factor for OS (HR=1.008, P=0.042). The Vn-PRS model had the lowest -2 log likelihood (-2LL) among all the models. Conclusion Voxel subtraction technique can accurately assess the size of recurrent tumors in rGBM patients. V, Vn and rNTR can be used for prognosis, and Vn is the most valuable predictor for PRS, which can provide a reliable reference for clinical evaluation of the extent of lesions and survival time of patients.

Pre-service mathematics teachers' content knowledge is an important issue. Therefore, detailed studies are needed to be conducted on mathematical topics. The study examines preservice elementary mathematics teachers' (PEMTs) special content knowledge (SCK) of integer addition and subtraction in the context of using multiple representations, explaining mathematical reasons lying behind the concepts and justifying them. The findings obtained from the written responses of 42 PEMTs reveal that preservice teachers do not have sufficient and balanced special content knowledge. This is especially more so in the case of addition and subtraction of numbers with opposite signs. The preservice teachers were observed to have more difficulty in using the number line model compared to the use of other representations. The findings offer some indicators about how PEMTs understand integer addition and subtraction through multiple representations and why more emphasis on the SCK components

The current study aims to show the transition skills of sixth grade students between the representations (numerical, model, number line and verbal) given in addition-subtraction operations in fractions and to analyse the ability of the students to construct each representation type. In this research, case study method was used in terms of the subject and process followed. The study group of the research is the sixth grade students of three middle schools in Kastamonu province placed in the northern part of Turkey. The research participants consisted of 59 students, 31 of which are male and 28 of which are female. Data collected through "Multiple Representations in Fraction Operations Test." According to research findings, it has been determined that the achievement of students in using different representations in operations with fractions is higher in addition operation compared to subtraction operation. In addition, it turns out that students are more successful in numerical-numerical, model-model, model-numerical, and numerical-model transitions compared to other transitions in both operation types. It was also found out that students fail in other representation types such as number line and verbal representation transition situations.

In this study, it was aimed to analyze the structure of prospective middle school mathematics teachers' problems posed with regard to given symbolic representation including addition and subtraction operations with integers. The study conducted with 96 last grade elementary school mathematics teacher candidates studying in Faculty of Education of Erciyes University in Turkey at the beginning of 2018 years. A Problem Posing Task including five items regarding addition and subtraction operations with integers and semi-structured interview forms were used as data gathering tools. Results indicated that prospective teachers had difficulties in choosing problem types with regard to the given operation structure. Prospective teachers presented less success in problem posing with integers having different signs. Besides, some of the prospective teachers used signs of integers and operations interchangeably and some others multiplied signs of integers and operations, and they gave meaning to the result of this multiplication while they were posing problems.

An adapted alternating treatments design was used to compare the effects of class-wide applications of Taped Problems (TP) and Explicit Timing (ET) interventions on digits correct per minute (DCPM) scores. The study also investigated whether initial fluency scores would differentiate intervention effectiveness between TP and ET procedures. Results showed that both TP and ET resulted in similar DCPM increases, with both approaches significantly outperforming a control condition. Although the interventions showed similar effectiveness at the class-wide level, the interaction between intervention type and initial fluency levels suggested a differential effect. For students with initial fluency scores in the frustrational range ([less than or equal to] 10 DCPM), it was found that TP resulted in a higher growth rate than both ET and the control. For students with initial fluency scores in the instructional range (>10 DCPM), both ET and TP interventions resulted in higher DCPM scores than control but did not differ from one another. The discussion focuses on using skill by treatment interactions to inform intervention selection, explores opportunities and challenges in this research area, and addresses study limitations.

Abstract Background Stroke is one of the main causes of disability, in which nearly 2/3 of survivors experience disability and interferes with the patient’s daily functional activities. Hypertension, dyslipidemia, obesity, and smoking habits are the main causes of stroke in young adults. Vascular abnormalities are also risk factor for stroke in young adults. Advanced imaging examinations such as cerebral digital subtraction angiography (DSA) can provide a clear picture of the vasculature of the blood vessels of the human brain and provide a real-time picture of the hemodynamic status, blood flow and collateral circulation of the cerebral vessels. Results There were approximately 999 patients who had DSA cerebral examination during the study period. The total young adult population was 147 [92 males (62.4%) and 55 females (37.6%)]. There were 82 patients with ischemic stroke (60.7%). The main etiology of ischemic stroke in this study was intracranial atherosclerotic disease (ICAD) [44 (53.65%)]. The young adult population had 53 hemorrhagic stroke patients (39.3%). The main cause of hemorrhagic stroke is hypertensive vasculopathy (41.5%), followed by a ruptured cerebral arteriovenous malformation (CAVM) (37.7%). There were 12 patients with cerebral sinus venous thrombosis (CSVT). Headache is the main complaint of patients with venous stroke, followed by seizures and hemiparesis. The transverse sinus is the most common site for occlusion (66.7%). Conclusion This study describes the characteristics and prevalence of stroke in young adults based on the results of cerebral DSA examination. Stroke in young adults is not uncommon. Several traditional risk factors in old age are now found in young people. Lifestyle modification is needed to reduce the prevalence of stroke in young adults.

近年来经前臂血管入路如桡动脉入路行神经介入治疗已被广泛应用，但部分患者因先天性桡动脉纤细或既往多次桡动脉穿刺后引起桡动脉狭窄甚至闭塞而无法继续经桡动脉入路完成治疗。本病例中患者因左侧颈内动脉起始部重度狭窄需进行介入治疗，其主动脉弓为牛角弓型，适合经桡动脉入路完成手术，然而该患者因既往多次经桡动脉入路进行手术，导致桡动脉纤细，无法进一步完成经桡动脉入路介入治疗。彩超检查发现患者尺动脉直径粗，能耐受彩超置入血管鞘，因此本研究尝试经尺动脉入路完成脑血管造影及颈动脉支架置入术。该患者手术顺利，无并发症发生，为后续经尺动脉入路行神经介入及治疗的研究提供参考。 Abstract: In recent years, the transforearm vascular approach such as radial artery approach has been widely used, but some patients cannot continue the radial artery approach due to congenital slender radial artery, radial artery stenosis or even occlusion after previous repeated radial artery punctures. In this case, the patient required interventional therapy for severe stenosis at the origin of the left internal carotid artery. The patient has a bovine aortic arch, which is suitable for the radial artery approach surgery. However, the patient had undergone several previous operations via the radial artery approach, resulting in a slender radial artery, and further radial artery approach for interventional therapy cannot be completed. The color Doppler ultrasonography found that the diameter of ulnar artery was thick enough for puncture and sheath placement. Therefore, this study tried to perform digital subtraction angiography and carotid artery stenting through ulnar artery approach. The operation was successfully completed without complications, providing a reference for the interventional surgery via ulnar artery approach.

Abstract Background This study was to prospectively investigate the feasibility of four-dimensional computed tomography angiography (4D-CTA) with electrocardiogram-gated (ECG) reconstruction for preoperative evaluation of morphological parameters, and compared with digital subtraction angiography (DSA). We also aimed to detect pulsation in unruptured intracranial aneurysms (UIAs) by using 4D-CTA, as a potential predicting factor of growth or rupture. Materials 64 patients with 64 UIAs underwent ECG-gated dynamic 4D-CTA imaging before treatment, of which 46 patients additionally underwent DSA. Original scanning data were reconstructed to produce 20 data sets of cardiac cycles with 5%-time intervals. The extent of agreement on UIAs morphological features assessed with 4D-CTA and DSA was estimated using the k coefficient of the Kappa test. The radiation doses were also calculated and compared between 4D-CTA and DSA. In the aneurysmal surgically treated in our institution, we were able to compare the surgical findings of the aneurysm wall with 4D-CTA images. We performed long-term follow-up on untreated patients. Results The morphological characteristics detected by 4D-CTA and DSA were consistent in aneurysm location (k = 1.0), shape (k = 0.76), maximum diameter (k = 0.94), aneurysm neck (k = 0.79) and proximity to parent and branch vessels (k = 0.85). 4D-CTA required lower radiation doses (0.32 ± 0.11 mSv) than DSA (0.84 ± 0.37 mSv, P

Let S be a semigroup. Our main results are that we describe the complex-valued solutions of the following functional equations g(xσ(y))=g(x)g(y)+f(x)f(y),x,y∈S,f(xσ(y))=f(x)g(y)+f(y)g(x),x,y∈S,\matrix{ {g\left( {x\sigma \left( y \right)} \right) = g\left( x \right)g\left( y \right) + f\left( x \right)f\left( y \right),} & {x,y \in S,} \cr {f\left( {x\sigma \left( y \right)} \right) = f\left( x \right)g\left( y \right) + f\left( y \right)g\left( x \right),} & {x,y \in S,} \cr } and f(xσ(y))=f(x)g(y)-f(y)g(x),x,y∈S,\matrix{ {f\left( {x\sigma \left( y \right)} \right) = f\left( x \right)g\left( y \right) - f\left( y \right)g\left( x \right),} & {x,y \in S,} \cr } where σ : S → S is an automorphism that need not be involutive. As a consequence we show that the first two equations are equivalent to their variants. We also give some applications.

Background One of the serious cardiovascular conditions is peripheral arterial disease; in which distinctive feature is diminished blood supply towards the lower extremities, frequently because of atherosclerotic occlusive disease. Methods We will compare arterial Doppler with digital subtraction angiography in peripheral lower limb occlusive arterial sickness; to determine Peripheral Arterial Disease along with its location and stenosis severity on Duplex Ultra-Sonography and Digital Subtraction Angiography; and to determine the segment-to-segment agreement of the arterial tree within Duplex Ultra-Sonography and Digital Subtraction Angiography. Implications This will encourage the participants for periodic investigation and proper use of medications which will improve hospital/facility outcome. It will be helpful for older individuals how are more susceptible to peripheral artery disease. A fair accurate treatment options will be given to patients. Limitations Findings will only be applicable to our organization because the study will be done at one tertiary care hospital, limiting their external validity and generalizability.

This study examines design principles for how to display financial information about a consumer loan that supports locating a value (e.g., What is the annual percentage rate (APR) for an 18-month loan?), comparing two values (e.g., Is the APR for a 24-month load greater than for an 18-month loan?), or subtracting two values (e.g., What is the difference in the APR for a 24-month load and an 18-month loan?). One hundred and thirty-three college students carried out these three types of tasks at a banking site that displayed information as a list (e.g., listing the value for interest rate, monthly payment, insurance cost, APR, amount financed, and total cost for a given duration ranging from 6 to 48 months) or as one of three types of tables or matrices (containing values for each of six variables across one axis and each of eight loan durations across the other). Accuracy and response time on each of the three types of tasks was tallied for each of the four groups. Consistent with the principle of distraction minimization, the list was the best display for locating a value. Consistent with the principle of conjoint alignment, a vertical matrix (with loan duration across columns) or horizontal matrix (with loan duration across rows) was the best for comparing two values, but an interactive matrix was less effective. Consistent with the principle of canonical form, a vertical matrix (with loan duration across columns) was the best for subtracting two values. Overall, the best information display depended on the type of task, consistent with cognitive theories of information processing. [ABSTRACT FROM AUTHOR]

Cerebral vascular angiography, or digital subtraction angiography (DSA), is essential for diagnosing neurological conditions but poses radiation risks. This study aims to analyze the impact of examination parameters and patient characteristics on the radiation dose received during DSA to optimize safety and minimize exposure. A retrospective analysis of 251 DSA procedures using the GE Innova IGS 630 dual-plane instrument was conducted. Data on dose area product (DAP) and air kerma (KERMA), along with patient and examination details, were collected. Statistical analyses, including Mann–Whitney, Kruskal–Wallis, and Spearman rank correlation tests, assessed the relationships between variables and radiation dose outcomes. Significant correlations were found between the sides examined (left, right, or both) and DAP (p < 0.0001) and KERMA (p < 0.0001) values, with bilateral studies showing the highest values. The post hoc Dunn tests showed that the ‘L + P’ group significantly differs from both the right group (p < 0.0001 and the left group (p < 0.0001). There is no significant difference between the ‘P’ group and the ‘L’ group (p-value = 0.53). These results suggest that the right and left (both) group have unique KERMA mGy values compared to the other two groups. A strong correlation (rS = 0.87) existed between DAP and KERMA. The number of projections significantly impacted radiation dose (rS = 0.61). Tube parameters (kV and mA) and skull size had low correlations with DAP and KERMA. Optimizing imaging protocols and individualizing parameters can significantly enhance patient safety and diagnostic efficacy while also reducing occupational exposure for medical staff.

PDR positioning is currently the core issue of autonomous positioning, there is a problem of high noise and interference in dynamic measurement using PDR (Pedestrian Dead Reckoning) MEMS (Micro-Electro-Mechanical System) device, which is often a low precision multi-source integration sensor. Two new models of improved spectral subtraction (ISS) and PDRS (PDR-Spectral subtraction) spectral subtraction are constructed in this paper according to the spectrum features of the periodic noise generated from personnel stepping in PDR positioning. It is proposed a two-stage noise reduction method of spectrum subtraction-Wiener filtering for obtaining the static magnetic sequence of personnel path and reducing the real-time noise in PDR positioning, which main mechanism is to use the step power spectrum as the background noise for primary noise reduction, secondary Wiener filtering noise reduction according to the correlation between the denoised signal and the reference signal. A self-made MEMS-based positioning device HBEQ-1 and a high-precision magnetometer FVM-400 were used to collect dynamic and static magnetic value from the test area, and a spectral subtraction-Wiener two-stage noise reduction test was carried out. The experimental results show that the improved ISS spectral subtraction and PDRS spectral subtraction are effective in denoising the dynamic magnetic measurement, but there is still a certain deviation between the peak value and the amplitude of the denoised signal. After secondary noise reduction by Wiener filtering, the signal morphology similarity of magnetic curve and the reference reached 0.7975, and the matched path values of the dynamic magnetic value reached around 12000–13000. It showed that the denoising effect is good and the waveform of denoised signal and the reference signal is similar, but there is spatial stretching of the overall magnetic sequence. It is shown that the spectral subtraction-Wiener noise reduction method cannot eliminate the inertial delay bias generated by personnel walking, the processing does not distort the magnetic signal, maintains spatial characteristics of the static magnetic sequence of personnel path, which is an excellent model for noise reduction of dynamic magnetic measurements in PDR positioning.