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Article ; Online: Perceptual grouping strategies and texture segmentation: Strategic connections and selection.

Kon, Maria / Francis, Gregory

2023 Volume 210, Page(s) 108263

Abstract: In a series of articles, Jacob Beck proposed that a variety of texture segmentation phenomena occurs due to emergent features that arise from "links" between elements with appropriate local properties, such as alignment, orientation, and proximity. His ... ...

Abstract	In a series of articles, Jacob Beck proposed that a variety of texture segmentation phenomena occurs due to emergent features that arise from "links" between elements with appropriate local properties, such as alignment, orientation, and proximity. His findings and ideas guided theoretical and computational models, and some of his demonstrations became textbook knowledge about visual perception. We build on this work in two ways. First, we provide a modern replication of a classic texture segmentation study using a much larger sample size. Overall, the replication agrees with Beck's original findings, although there are some quantitative differences. Second, we show how to apply a quantitative model of visual cortex to Beck's experiment and demonstrate that the model can explain many aspects of Beck's findings. Key to the model's success is cognitive control of connections between individual elements (akin to Beck's "links" between elements) and a selection mechanism that makes it easy to identify how well elements within a region connect and how well different regions are disconnected. Overall, the model supports Beck's claim that local properties can facilitate patterns of connections between stimulus elements and that some connection patterns allow an observer to easily distinguish textures.
MeSH term(s)	Humans ; Visual Perception ; Vision, Ocular ; Visual Cortex ; Pattern Recognition, Visual
Language	English
Publishing date	2023-06-02
Publishing country	England
Document type	Journal Article
ZDB-ID	200427-6
ISSN	1878-5646 ; 0042-6989
ISSN (online)	1878-5646
ISSN	0042-6989
DOI	10.1016/j.visres.2023.108263
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Article ; Online: A replication and re-analysis of a classic texture segmentation study.

Francis, Gregory / Kon, Maria

Attention, perception & psychophysics

2023

Abstract: A classic finding reported in Beck (1966a) is that observers tend to indicate a more natural texture break between a set of T's and tilted T's than between a set of T's and backward L's. This finding has played a prominent role in discussions about the ... ...

Abstract	A classic finding reported in Beck (1966a) is that observers tend to indicate a more natural texture break between a set of T's and tilted T's than between a set of T's and backward L's. This finding has played a prominent role in discussions about the properties of texture segmentation and in the development of computational theories of texture segmentation. Due to the small sample size of the original study, we replicated the original experiment with a larger sample. Regrettably, we discovered that the description in Beck (1966a) is insufficient to allow us to reproduce the stimuli. For our replication, we created stimuli that seem consistent with the spirit of the original study. The results of the replication study partly match Beck's original data ([Formula: see text]), but conclusions indicated by these results deviate from some of Beck's key conclusions. We also further explored the influential claim derived from a second experiment in Beck (1966a) that texture segmentation was not related to the perceived similarity of elements. Contrary to this claim, a re-analysis of Beck's data indicates the counterintuitive conclusion that observers tend to indicate stronger texture segmentation between regions that are rated as being more similar. In a replication of the second experiment, this relation flipped so that the replication observers indicated stronger texture segmentation for regions with lower similarity ratings. Despite being influential, we conclude that there are substantial problems with the stimuli, analyses, and conclusions in Beck (1966a).
Language	English
Publishing date	2023-12-20
Publishing country	United States
Document type	Journal Article
ZDB-ID	2464550-3
ISSN	1943-393X ; 1943-3921
ISSN (online)	1943-393X
ISSN	1943-3921
DOI	10.3758/s13414-023-02824-z
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Article ; Online: Perceptual Grouping Strategies in a Letter Identification Task: Strategic Connections, Selection, and Segmentation.

Kon, Maria / Francis, Gregory

Attention, perception & psychophysics

2022 Volume 84, Issue 6, Page(s) 1944–1963

Abstract: Although perceptual grouping has been widely studied, its mechanisms remain poorly understood. We propose a neural model of grouping that, through top-down control of its circuits, implements a grouping strategy involving both a connection strategy ( ... ...

Abstract	Although perceptual grouping has been widely studied, its mechanisms remain poorly understood. We propose a neural model of grouping that, through top-down control of its circuits, implements a grouping strategy involving both a connection strategy (which elements to connect) and a selection strategy (that defines spatiotemporal properties of a selection signal to segment target elements and facilitate identification). We apply the model to a letter discrimination task that investigated relationships among uniform connectedness and the grouping principles of proximity and shape similarity. Participants reported whether small circles formed a global letter E or H, and these circles could be connected by a line or be embedded in a matrix of squares. In the model, a good grouping strategy for this task consists of a connection strategy that connects circles but not squares for all conditions and a selection strategy that uses a selection signal of varying size, depending on whether squares were present. Consistent with empirical results, which were verified in two replication studies, model performance is worse with distractor squares, and line connectors improve performance only in the condition with squares. Rather than relying on abstract grouping principles, we show how the empirical results can be explained in terms of observers implementing a task-dependent grouping strategy that promotes overall performance.
Language	English
Publishing date	2022-06-14
Publishing country	United States
Document type	Journal Article
ZDB-ID	2464550-3
ISSN	1943-393X ; 1943-3921
ISSN (online)	1943-393X
ISSN	1943-3921
DOI	10.3758/s13414-022-02515-1
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Article ; Online: Cortical circuits for top-down control of perceptual grouping.

Kon, Maria / Francis, Gregory

Neural networks : the official journal of the International Neural Network Society

2022 Volume 151, Page(s) 190–210

Abstract: A fundamental characteristic of human visual perception is the ability to group together disparate elements in a scene and treat them as a single unit. The mechanisms by which humans create such groupings remain unknown, but grouping seems to play an ... ...

Abstract	A fundamental characteristic of human visual perception is the ability to group together disparate elements in a scene and treat them as a single unit. The mechanisms by which humans create such groupings remain unknown, but grouping seems to play an important role in a wide variety of visual phenomena, and a good understanding of these mechanisms might provide guidance for how to improve machine vision algorithms. Here, we build on a proposal that some groupings are the result of connections in cortical area V2 that join disparate elements, thereby allowing them to be selected and segmented together. In previous instantiations of this proposal, connection formation was based on the anatomy (e.g., extent) of receptive fields, which made connection formation obligatory when the stimulus conditions stimulate the corresponding receptive fields. We now propose dynamic circuits that provide greater flexibility in the formation of connections and that allow for top-down control of perceptual grouping. With computer simulations we explain how the circuits work and show how they can account for a wide variety of Gestalt principles of perceptual grouping, texture segmentation tasks, amodal illusory contours, and ratings of perceived groupings. We propose that human observers use such top-down control to implement task-dependent connection strategies that encourage particular groupings of stimulus elements in order to promote performance on various visual tasks.
MeSH term(s)	Form Perception ; Humans ; Illusions ; Vision, Ocular ; Visual Cortex ; Visual Perception
Language	English
Publishing date	2022-03-31
Publishing country	United States
Document type	Journal Article
ZDB-ID	740542-x
ISSN	1879-2782 ; 0893-6080
ISSN (online)	1879-2782
ISSN	0893-6080
DOI	10.1016/j.neunet.2022.03.029
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Article ; Online: Quantifying the Magnitude and Longevity of the Effect of Repetitive Head Impacts in Adolescent Soccer Players: Deleterious Effect of Long Headers Extend Beyond a Month.

Shamloo, Farzin / Kon, Maria / Ritter, Elizabeth / Sereno, Anne B

Neurotrauma reports

2023 Volume 4, Issue 1, Page(s) 267–275

Abstract: There is growing interest in the effects of sports-related repetitive head impacts (RHIs) on athletes' cognitive capabilities. This study examines the effect of RHIs in data collected from adolescent athletes to estimate the magnitude and longevity of ... ...

Abstract	There is growing interest in the effects of sports-related repetitive head impacts (RHIs) on athletes' cognitive capabilities. This study examines the effect of RHIs in data collected from adolescent athletes to estimate the magnitude and longevity of RHIs on sensorimotor and cognitive performance. A non-linear regression model estimated the longevity of RHI effects by adding a half-life parameter embedded in an exponential decay function. A model estimate of this parameter allows the possibility of RHI effects to attenuate over time and introduces a mechanism to study the cumulative effect of RHIs. The posterior distribution of the half-life parameter associated with short-distance headers (<30 m) is centered around 6 days, whereas the posterior distribution of the half-life parameter associated with long-distance headers extends beyond a month. Additionally, the magnitude of the effect of each short header is around 3 times smaller than that of a long header. The results indicate that, on both tasks, response time (RT) changes after long headers are bigger in magnitude and last longer compared to the effects of short headers. Most important, we demonstrate that deleterious effects of long headers extend beyond 1 month. Although estimates are based on data from a relatively short-duration study with a relatively small sample size, the proposed model provides a mechanism to estimate long-term behavioral slowing from RHIs, which may be helpful to reduce the risk of additional injury. Finally, differences in the longevity of the effects of short and long RHIs may help to explain the large variance found between biomechanical input and clinical outcome in studies of concussion tolerance.
Language	English
Publishing date	2023-04-21
Publishing country	United States
Document type	Journal Article
ISSN	2689-288X
ISSN (online)	2689-288X
DOI	10.1089/neur.2022.0085
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Article ; Online: Evaluating estrus synchronization and early pregnancy detection in Ossimi sheep: The influence of fluorogestone acetate treatment duration and dosage.

Salama, Maha S / Ashour, Mohey A / Taher, Ehab S / El-Kon, Ismail / Sayed, Samy / Alkeridis, Lamya Ahmed / Stefan, Batrina / Ana-Maria, Imbrea / Al-Shuraym, Laila A / Shukry, Mustafa

Veterinary and animal science

2024 Volume 24, Page(s) 100351

Abstract: Estrus synchronization is important for improving sheep reproduction. To enhance sheep reproduction efficiency, this study investigated the impact of different durations (7 vs. 14 days) and fluorogestone acetate (FGA) doses in intravaginal sponges on ... ...

Abstract	Estrus synchronization is important for improving sheep reproduction. To enhance sheep reproduction efficiency, this study investigated the impact of different durations (7 vs. 14 days) and fluorogestone acetate (FGA) doses in intravaginal sponges on estrus synchronization and early pregnancy detection in Ossimi sheep. Two hundred ewes were evenly divided into two groups, each receiving a full 40 mg or a halved 20 mg FGA sponge for their respective durations. The study aimed to optimize breeding efficiency by examining the effectiveness of these treatments in synchronizing estrous cycles and by evaluating the use of serum levels of pregnancy-associated glycoprotein 1 (PAG1) and progesterone (P
Language	English
Publishing date	2024-04-12
Publishing country	Netherlands
Document type	Journal Article
ISSN	2451-943X
ISSN (online)	2451-943X
DOI	10.1016/j.vas.2024.100351
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Article ; Online: Determinants of Early Marriage and Construction of Gender Roles in South Sudan

Kon K. Madut

SAGE Open, Vol

2020 Volume 10

Abstract: This study examines socioeconomic factors that influence child marriage and gender relations ... by the GT analysis revealed that child marriage is influenced by social and economic factors and is ...

Abstract	This study examines socioeconomic factors that influence child marriage and gender relations in the post-independence South Sudan. Grounded Theory (GT) methodology is utilized to discuss how sociocultural construction of gender relationships and socialization can influence gender relations and equitable female and male contribution to the society. The sample consisted of 55 females and 36 males chosen at random ( n = 91), who took part either in a focus group discussion or one-on-one interview. The study covered the period from August 2015 to October 2017. The participants were drawn from four counties—Mapel, Kabu, Besselia, and Jury River—of the Wau State, in Bahr el Ghazal. Findings yielded by the GT analysis revealed that child marriage is influenced by social and economic factors and is perceived as an acceptable social norm. This practice is further complicated by the effects of everlasting conflict, poverty, and high illiteracy rate in the society.
Keywords	History of scholarship and learning. The humanities ; AZ20-999 ; Social Sciences ; H
Subject code	300
Language	English
Publishing date	2020-05-01T00:00:00Z
Publisher	SAGE Publishing
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Revisiting the relevance of Hirano bodies in neurodegenerative diseases.

Yoshida, Koji / Forrest, Shelley L / Ichimata, Shojiro / Tanaka, Hidetomo / Kon, Tomoya / Tartaglia, Maria Carmela / Tator, Charles H / Lang, Anthony E / Nishida, Naoki / Kovacs, Gabor G

Neuropathology and applied neurobiology

2024 Volume 50, Issue 2, Page(s) e12978

Abstract: Aims: Hirano bodies (HBs) are eosinophilic pathological structures with two morphological phenotypes commonly found in the hippocampal CA1 region in Alzheimer's disease (AD). This study evaluated the prevalence and distribution of HBs in AD and other ... ...

Abstract	Aims: Hirano bodies (HBs) are eosinophilic pathological structures with two morphological phenotypes commonly found in the hippocampal CA1 region in Alzheimer's disease (AD). This study evaluated the prevalence and distribution of HBs in AD and other neurodegenerative diseases. Methods: This cross-sectional study systematically evaluated HBs in a cohort of 193 cases with major neurodegenerative diseases, including AD (n = 91), Lewy body disease (LBD, n = 87), progressive supranuclear palsy (PSP, n = 36), multiple system atrophy (MSA, n = 14) and controls (n = 26). The prevalence, number and morphology of HBs in the stratum lacunosum (HBL) and CA1 pyramidal cell layer were examined. In addition, we investigated the presence of HBs in five additional hippocampal subregions. Results: The morphological types of HBs in CA1 were divided into three, including a newly discovered type, and were evaluated separately, with their morphology confirmed in three dimensions: (1) classic rod-shaped HB (CHB), (2) balloon-shaped HB (BHB) and the newly described (3) string-shaped HB (SHB). The prevalence of each HB type differed between disease groups: Compared with controls, for CHB in AD, AD + LBD, PSP and corticobasal degeneration, for BHB in AD + LBD and PSP, and SHB in AD + LBD and PSP were significantly increased. Regression analysis showed that CHBs were independently associated with higher Braak NFT stage, BHBs with LBD and TDP-43 pathology, SHBs with higher Braak NFT stage, PSP and argyrophilic grain disease and HBLs with MSA. Conclusions: This study demonstrates that HBs are associated with diverse neurodegenerative diseases and shows that morphological types appear distinctively in various conditions.
MeSH term(s)	Humans ; Cross-Sectional Studies ; Alzheimer Disease/pathology ; Lewy Body Disease/pathology ; Supranuclear Palsy, Progressive/pathology ; Multiple System Atrophy
Language	English
Publishing date	2024-04-18
Publishing country	England
Document type	Journal Article
ZDB-ID	80371-6
ISSN	1365-2990 ; 0305-1846
ISSN (online)	1365-2990
ISSN	0305-1846
DOI	10.1111/nan.12978
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Article ; Online: Rare Mycobacteria and HIV in Children: Two Case Reports.

Johnson, Sarah M / Piñera, Cecilia / Whittaker, Elizabeth / Kirkhope, Natalie / Kon, Onn M / Satta, Giovanni / Balcells, Maria Elvira / Foster, Caroline

Clinical drug investigation

2022 Volume 42, Issue 6, Page(s) 541–547

MeSH term(s)	Child ; HIV Infections/diagnosis ; HIV Infections/drug therapy ; Humans ; Mycobacterium ; Mycobacterium Infections/microbiology
Language	English
Publishing date	2022-05-16
Publishing country	New Zealand
Document type	Case Reports ; Letter
ZDB-ID	1220136-4
ISSN	1179-1918 ; 0114-2402 ; 1173-2563
ISSN (online)	1179-1918
ISSN	0114-2402 ; 1173-2563
DOI	10.1007/s40261-022-01153-7
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Article: Treatment and Outcomes of Radiation-Induced Soft Tissue Sarcomas of the Extremities and Trunk-A Systematic Review of the Literature.

Inchaustegui, Maria L / Kon-Liao, Kelly / Ruiz-Arellanos, Kim / Silva, George Aquilino E / Gonzalez, Marcos R / Pretell-Mazzini, Juan

Cancers

2023 Volume 15, Issue 23

Abstract: Introduction: Radiation-induced soft tissue sarcomas (RISs) are rare secondary malignancies with a dire prognosis. The literature on the management of these tumors remains scarce due to their low incidence. Our systematic review sought to assess the ... ...

Abstract	Introduction: Radiation-induced soft tissue sarcomas (RISs) are rare secondary malignancies with a dire prognosis. The literature on the management of these tumors remains scarce due to their low incidence. Our systematic review sought to assess the treatment alternatives and outcomes of patients with RIS. Methods: A systematic review was conducted following the PRISMA guidelines. Our study was registered in PROSPERO (ID: CRD42023438415). Quality assessment was performed using the STROBE checklist. Weighted means for both continuous and categorical values were calculated. Results: Twenty-one studies comprising 1371 patients with RIS were included. The mean latency period from radiation to RIS diagnosis was 14 years, and the mean radiation dose delivered to the primary malignancy was 29.2 Gy. The most common histological type was undifferentiated pleomorphic sarcoma (42.2%), and 64% of all tumors were high-grade. The trunk was the most common location (59%), followed by extremities (21%) and pelvis (11%). Surgery was performed in 68% of patients and, among those with an appendicular tumor, the majority (74%) underwent limb-salvage surgery. Negative margins were attained in 58% of patients. Chemotherapy and radiotherapy were administered in 29% and 15% of patients, respectively. The mean 5-year overall survival was 45%, and the local recurrence and metastasis rates were 39% and 27%, respectively. Conclusions: In our study, the most common treatment was surgical resection, with RT and chemotherapy being administered in less than one third of patients. Patients with RIS exhibited poor oncologic outcomes. Future studies should compare RIS with de novo STS while controlling for confounders.
Language	English
Publishing date	2023-11-25
Publishing country	Switzerland
Document type	Journal Article ; Review
ZDB-ID	2527080-1
ISSN	2072-6694
ISSN	2072-6694
DOI	10.3390/cancers15235584
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