Spatial Realignment Research Articles

Comprehensive Evaluation of Multispectral Image Registration Strategies in Heterogenous Agriculture Environment.

This article is focused on the comprehensive evaluation of alleyways to scale-invariant feature transform (SIFT) and random sample consensus (RANSAC) based multispectral (MS) image registration. In this paper, the idea is to extensively evaluate three such SIFT- and RANSAC-based registration approaches over a heterogenous mix containing Triticum aestivum crop and Raphanus raphanistrum weed. The first method is based on the application of a homography matrix, derived during the registration of MS images on spatial coordinates of individual annotations to achieve spatial realignment. The second method is based on the registration of binary masks derived from the ground truth of individual spectral channels. The third method is based on the registration of only the masked pixels of interest across the respective spectral channels. It was found that the MS image registration technique based on the registration of binary masks derived from the manually segmented images exhibited the highest accuracy, followed by the technique involving registration of masked pixels, and lastly, registration based on the spatial realignment of annotations. Among automatically segmented images, the technique based on the registration of automatically predicted mask instances exhibited higher accuracy than the technique based on the registration of masked pixels. In the ground truth images, the annotations performed through the near-infrared channel were found to have a higher accuracy, followed by green, blue, and red spectral channels. Among the automatically segmented images, the accuracy of the blue channel was observed to exhibit a higher accuracy, followed by the green, near-infrared, and red channels. At the individual instance level, the registration based on binary masks depicted the highest accuracy in the green channel, followed by the method based on the registration of masked pixels in the red channel, and lastly, the method based on the spatial realignment of annotations in the green channel. The instance detection of wild radish with YOLOv8l-seg was observed at a mAP@0.5 of 92.11% and a segmentation accuracy of 98% towards segmenting its binary mask instances.

Sort-term adaptations on bilateral body weight-bearing symmetry and postural control through the application of rotary prisms in healthy children

Background: Motor-control is organized by coordinated sensory systems which integrate for the preparation of movement. Certain visuoperceptive disorders may impair proper development of motor control during childhood, thereby impacting functional aspects like bilateral weight-bearing symmetry. Rotary prisms (RPs) are a rehabilitation modality that have shown promise in facilitating motor-control and spatial-realignment for adults, improving weight-bearing symmetry, often evaluated by indexes like the normalized symmetry index (NSI%). However, less is known for the short-term effect of RPs on NSI% and consequent effects on functional capacity in healthy children. Methods: We evaluated the acute and short-term chronic effect of RPs in fourteen healthy children (8.8±1.1 years) on NSI% and the total execution time (s) of a dynamic balance sit-to-stand task (SITS). Measurements were performed at baseline, immediately following RP application (immediate phase) and 10 min following RP removal (spatial re-alignment). Results: We detected an overall main effect of time on NSI% (F=15.1, p<0.001, η2=.54), improving both immediate (-67.3%, 3.4±4.46%, p<0.001) and spatial re-alignment phases (-55.3%, 5.2±4.3%, p<0.001) compared to baseline (9.7±1.9 %). Moreover, no significant differences for NSI% between immediate and spatial re-alignment phases were detected (p>0.05). However, TUT of the SITS task remained unaffected (F=1.13, p>0.05). Conclusions: Non-significant differences for NSI% between immediate and spatial re-alignment phases indicate that short-term neural adaptations may persist following the removal of RPs in healthy children. Indicating the potential suitability of RPs in neurorehabilitation for children with balance impairments, such as pre-existing sensory motor dysfunctions and others.

Age-related changes to electroencephalographic markers of visuomotor error processing and learning in prism adaptation

Aging is associated with changes in cognitive function, including declines in learning, memory, and executive function. Prism adaptation (PA) is a useful paradigm to measure changes in explicit and implicit mechanisms of visuo-motor learning with age, but the neural correlates are not well understood. In the present study, we used PA to investigate visuo-motor learning and error processing in older adults. Twenty older adults (56–85 yrs) and 20 younger adults (18–33 yrs) underwent a goal-oriented reaching task while wearing prism goggles as continuous EEG was recorded to examine neural correlates of error detection. We examined behavioural measures of PA, as well as ERP components previously found associated with the early and late phases of adaptation to visual distortion caused by the prism goggles. Our results indicate important age-related behavioural and neurophysiological differences. Older adults reached more slowly than younger adults but showed the same accuracy throughout the prism exposure. Older adults also displayed larger aftereffects, indicating preserved visuomotor adaptation. EEG results indicated similar initial error processing in older and younger adults, as measured by the feedback error related negativity (FRN). As seen previously in young adults, the P3a and P3b declined over the prism exposure phase in both groups. Older adults displayed reduced P3a amplitude compared to the younger group in the early phase of adaptation, however, suggesting reduced attentional orienting. Finally, the older group exhibited a greater P3b amplitude compared to the younger group in the later phases of adaptation, potentially a marker of enhanced context updating underlying spatial realignment, leading to their larger aftereffect. Implications for age-related learning differences and clinical applications are discussed.

SOVIET AND POST-SOVIET TRANSFORMATIONS OF URBAN SYSTEM: CASE OF KAZAKHSTAN FROM 1979 TO 2022

This study analyzes the transformation of the urban system in Kazakhstan from 1979 to 2022 by studying the interrelationship between population change in large cities and demographic trends in nearby towns and rural areas. The findings suggest that the collapse of the USSR triggered a large-scale spatial realignment of the population leading to dramatic changes in the population size of urban settlements. The estimations largely failed to confirm relationships between the growth of large cities vs population change in mid-size and small urban settlements that would hold throughout the entire sample period. However, the analysis of district-level data showed that remote and rural areas were more prone to depopulation while districts around rapidly growing large cities had significantly higher rates of population growth. The population in large cities and regional centers was found to be growing much faster than in periphery areas, which is very much in line with findings from studies done on other former Soviet states.

Conflict and the changing geography of state capacity: Ukraine since 2013

ABSTRACT Considerable attention has focused on Ukraine as a divided country along ethno-cultural lines. But regional economic differences and trends over time are the primary drivers that influence citizens’ wellbeing and likewise contribute to a sense of place. This article focuses on how Ukraine’s economic development has unfolded across the country during a time of conflict and how these changes can be understood. Using the framework of state capacity, aggregate data reflective of human security are adduced to illustrate and suggest reasons for these shifting patterns and the implications thereof for a postwar Ukraine. Findings suggest that the spatial realignment of Ukraine’s economy has been and will continue to be a function of location, markets, and human capital.

Impact of Spatial Realignment of Community Streets on Traffic calming and Promotion of Physical Activity.

Impact of Spatial Realignment of Community Streets on Traffic calming and Promotion of Physical Activity.

Delivering spatially comparable inference on the risks of multiple severities of respiratory disease from spatially misaligned disease count data.

Population-level disease risk varies between communities, and public health professionals are interested in mapping this spatial variation to monitor the locations of high-risk areas and the magnitudes of health inequalities. Almost all of these risk maps relate to a single severity of disease outcome, such as hospitalization, which thus ignores any cases of disease of a different severity, such as a mild case treated in a primary care setting. These spatially-varying risk maps are estimated from spatially aggregated disease count data, but the set of areal units to which these disease counts relate often varies by severity. Thus, the statistical challenge is to provide spatially comparable inference from multiple sets of spatially misaligned disease count data, and an additional complexity is that the spatial extents of the areal units for some severities are partially unknown. This paper thus proposes a novel spatial realignment approach for multivariate misaligned count data, and applies it to the first study delivering spatially comparable inference for multiple severities of the same disease. Inference is via a novel spatially smoothed data augmented MCMC algorithm, and the methods are motivated by a new study of respiratory disease risk in Scotland in2017.

The ‘Tamasha’ genre of Marathi cinema: imbrications of a vernacular cultural space

ABSTRACT It is often observed that after the success of Sangtye Aika (Anant Mane, 1959) the Marathi film became tantamount to the tamasha genre. The rise of this film genre though also influenced the performance forms of the tamasha and lavani. Drawing from these observations, this paper presents a critical reassessment of the tamasha genre of Marathi cinema. The vernacular habitus of the tamasha enabled an amenable spatial realignment of the Marathi cinema after the 1960s. This in turn shaped towards a liminality of the Marathi cultural space. This historical inter-exchange suggests a cultural politics of and about performance. The paper argues that the regional specificity of the tamasha genre is an imbrication of two sites of performance: the first is the contexts, settings, and literary expressions of the tamasha as practiced in front of an audience; and the second in the filmic articulations of specific aspects of these performances, in narratives reflecting the lives and conflicts of tamasha performers. Referencing seminal works on lavani literature, the article observes that the tamasha genre was enmeshed in the processes of textualizing the lavani folk poetry, and therefore was influential in forging a vernacular cultural space.

Attenuation of motion artifacts in fMRI using discrete reconstruction of irregular fMRI trajectories (DRIFT).

Numerous studies report motion as the most detrimental source of noise and artifacts in fMRI. Current motion correction methods fail to completely address the motion problem. Retrospective techniques such as spatial realignment can correct for between-volume misalignment but fail to address within volume contamination and spin-history artifacts. Prospective motion correction can prevent spin-history artifacts but currently cannot update the gradients fast enough to remove k-space filling artifacts, calling for a hybrid approach to fully address these problems. Motion can be mathematically formulated into the MR signal equation to describe the motion artifacts at their origin in k-space. From these equations, it is demonstrated that different motions have different effects on the signal. A novel motion correction algorithm is designed from these equations to remove motion-induced artifacts directly in k-space, discrete reconstruction of irregular fMRI trajectory (DRIFT). This method is evaluated rigorously using fMRI simulations and data from a rotating phantom inside the scanner. The results indicate that although some motion types have negligible effects on the MR signal, others produce catastrophic and lasting artifacts even after motion cessation. In simulation, DRIFT is able to remove motion artifacts in the absence of spin history. In a phantom scan, DRIFT significantly attenuates the motion artifacts in the fMRI data. Neither prospective nor retrospective motion correction methods could completely remove the motion artifacts from the fMRI data. However, DRIFT, as a retrospective technique, when combined with prospective motion correction, can eliminate a significant portion of motion artifacts.

U.S. and China: The world's high-tech industry pre-eminent powers. A comparative analysis of positions

Subject. This article deals with the issues related to industrialization and spatial realignment of forces in the world industry architecture at the regional and global levels. Objectives. The article aims to describe the processes in the modern manufacturing industry and show the growth of China's share in the global production and export of knowledge-intensive and high-tech industry products in comparison with the indicators of the United States, the previous world industry leader. Methods. For the study, we used a comparative analysis. Results. The article compares the changes in industrial development indicators of the United States and China since the beginning of the 21st century and defines the positions of these countries in the development of knowledge-intensive and high-tech goods and services. Conclusions. China came out on top in the world concerning the export of all groups of high-tech goods and services. It is also the leader in global production and exports of medium- and high-tech products. China is slightly inferior to the United States in the production of high-tech industry products with the most intensive use of engineering development.

Did the party system change from 2012–2016?

ABSTRACT We test the implications of the spatial realignment framework against data from the 2012–2016 electoral cycle. The data, which come from the 2011–2016 Voter Study Group survey, include 19 items asked of the same 4705 respondents in two periods. Social issues improved in their ability to separate liberals from conservatives, as well as Republican from Democratic voters. There was limited but statistically significant decline in polarization on some economic items (except trade). Decreased inter-party division on economic items has come with increased intra-party division, albeit asymmetrically between parties and across issues. Increased intra-party divisions are due to vote-switchers not having adopted their new parties’ positions. The changes we find are small and mostly consistent with spatial realignment. Overall, they amount to diminution of class-based politics, including on some social issues with redistributive implications.

Spatial Realignment of German Voters and Germany’s Regional Cleavage

This article seeks to explain the increase in the German Green party votes in 2019 European elections through the East-West cleavage. Using the 2018 German General Social Survey data, it identifies and compares the Green Party electorate in both regions in terms of conventional and supposed determinants of Green voting. Results of the multivariate analysis equally support both models, indicating left-wing voters as the main source of the Greens’ electoral gains across Germany. However, while in the East the Greens were supported primarily by the electorate of the Social Democratic party dissatisfied with the activity of this party, Western Germans exhibited a trend of left-leaning voters’ backlash against the rise of the radical right party Alternative for Germany through Green voting. This realignment is explicated by the persistent specifics of German regional party politics combined with intrinsic value distinctions of their dwellers, and recent shifts in party-voters ties.

Visual Feedback Modulates Aftereffects and Electrophysiological Markers of Prism Adaptation.

Prism adaptation (PA) is both a model for visuomotor learning and a promising treatment for visuospatial neglect after stroke. The task involves reaching for targets while prism glasses horizontally displace the visual field. Adaptation is hypothesized to occur through two processes: strategic recalibration, a rapid self-correction of pointing errors; and spatial realignment, a more gradual adjustment of visuomotor reference frames that produce prism aftereffects (i.e., reaching errors upon glasses removal in the direction opposite to the visual shift). While aftereffects can ameliorate neglect, not all patients respond to PA, and the neural mechanisms underlying successful adaptation are unclear. We investigated the feedback-related negativity (FRN) and the P300 event-related potential (ERP) components as candidate markers of strategic recalibration and spatial realignment, respectively. Healthy young adults wore prism glasses and performed memory-guided reaching toward vertical-line targets. ERPs were recorded in response to three different between-subject error feedback conditions at screen-touch: view of hand and target (Experiment 1), view of hand only (Experiment 2), or view of lines to mark target and hand position (view of hand occluded; Experiment 3). Conditions involving a direct view of the hand-produced stronger aftereffects than indirect hand feedback, and also evoked a P300 that decreased in amplitude as adaptation proceeded. Conversely, the FRN was only seen in conditions involving target feedback, even when aftereffects were smaller. Since conditions producing stronger aftereffects were associated with a phase-sensitive P300, this component may index a “context-updating” realignment process critical for strong aftereffects, whereas the FRN may reflect an error monitoring process related to strategic recalibration.

Untethered firing fields and intermittent silences: Why grid-cell discharge is so variable.

Grid cells in medial entorhinal cortex are notoriously variable in their responses, despite the striking hexagonal arrangement of their spatial firing fields. Indeed, when the animal moves through a firing field, grid cells often fire much more vigorously than predicted or do not fire at all. The source of this trial-to-trial variability is not completely understood. By analyzing grid-cell spike trains from mice running in open arenas and on linear tracks, we characterize the phenomenon of "missed" firing fields using the statistical theory of zero inflation. We find that one major cause of grid-cell variability lies in the spatial representation itself: firing fields are not as strongly anchored to spatial location as the averaged grid suggests. In addition, grid fields from different cells drift together from trial to trial, regardless of whether the environment is real or virtual, or whether the animal moves in light or darkness. Spatial realignment across trials sharpens the grid representation, yielding firing fields that are more pronounced and significantly narrower. These findings indicate that ensembles of grid cells encode relative position more reliably than absolute position.

How “Peasant Apartments” Could Undermine Rural Governance in China: Spatial Realignment, Moral Reconfiguration and Local Authority

AbstractA seismic change in the residential pattern is emerging in rural China today: traditional rural houses have been rapidly erased from the face of the countryside with large numbers of peasants being relocated to modern high-rise buildings. This process of “peasant elevation” has had a monumental impact on rural China. It redefines the entitlement to land use by the rural citizenry and negotiations for a new regime of property rights concerning land administration, while, most importantly, it undermines the position of the local state in rural China, whose authority is an aggregation of three distinctive elements: coercive power inherent in the state apparatus, control over economic resources, and resonance with local morality. Based on original data collected in Chongqing, Nantong and Dezhou, this paper argues that the comprehensive uprooting of the Chinese peasantry from the land and the resulting complications have caused moral disorientation among the relocated peasants and fragmentation of local authority. The difficulty in establishing community identity in the new setting has further undermined local governance. This may in turn trigger a wave of social and political tensions that may eventually turn out to be a major political challenge to the regime for years to come.

Visuomotor adaptation in the absence of input from early visual cortex

Prism adaptation is a time-honored tool for studying how the motor system adapts to sensory perturbations. Past research on the neural substrates of prism adaptation has implicated the posterior parietal cortex (PPC) and the cerebellum, under the assumption that these structures gain their visual input from the dominant retinogeniculate pathway to V1. Here we question whether this pathway is even required for visuomotor adaptation to occur. To investigate this, we examined prism adaptation in ‘MC’, someone who is blind to static stimuli following bilateral lesions that encompass much of her occipital cortex and the caudal-most areas of ventrotemporal cortex. Remarkably, MC shows evidence of prism adaptation that is similar to healthy control participants. First, when pointing with either the left or the right hand, MC shows spatial realignment; the classical after-effect exhibited by most people when adapting to displacing prisms. Second, MC demonstrates strategic recalibration – a reduction in her pointing error over time – that is similar in magnitude to healthy controls. These findings suggest that the geniculostriate pathway is not necessary for visuomotor adaptation to take place. Alternatively, we suggest that an extrageniculostriate pathway which provides visual inputs to the cerebellum from area MT and the PPC via the dorsolateral pons plays a significant and appreciable role in the guidance of unconscious automatic visuomotor adaptation.

Bi-cephalic parietal and cerebellar direct current stimulation interferes with early error correction in prism adaptation: Toward a complex view of the neural mechanisms underlying visuomotor control

Prism Adaptation (PA) represents a valid tool to assess short-term visuomotor plasticity. Two adaptive processes are involved during PA: recalibration, contributing to early error compensation, and spatial realignment, contributing to after-effect development. Classical models on PA posit that adaptive mechanisms underlying PA rely on segregated regions in the brain. Indeed, they ascribe recalibration to the activity of the Posterior Parietal Cortex (PPC) and spatial realignment to the activity of the Cerebellum. The present experiment challenges the idea of a clear-cut separation of the role of the brain areas involved in PA, proposing an interpretation in terms of interrelated brain regions. To this purpose we interfered with the activity of the PPC and the Cerebellum by means of complementary protocols of stimulation.Bi-cephalic transcranial Direct Current Stimulation was delivered simultaneously on the PPC and the Cerebellum during PA in two groups of participants receiving real stimulation with opposite polarities (anode on PPC and cathode on Cerebellum or vice-versa) and in a control group (Sham stimulation). Differences in mean errors between groups were analyzed. Results show that the two groups of real stimulation exhibited larger displacements in early error compensation compared to the Sham Group, but they did not differ from each other. No group difference was found in late error compensation and after-effect. In conclusion, the present findings provide the first direct evidence that a brain circuit connecting the PPC and the Cerebellum is involved in early stages of visuomotor adaptation, and pave the way for updating classical models of PA.

Cerebellar contribution to spatial realignment: A tDCS study during multiple-step prism adaptation

Several processes are devoted to error reduction in response to a visual displacement, such as the one induced by wedge prisms. Strategic calibration and spatial realignment contribute to the iteratively process that allows a progressive adjustment of motor commands to reduce the magnitude of errors. Isolating the specific contributions to motor behaviour coming from these distinct processes is not possible using traditional single-step Prism Adaptation (PA), where participants are directly exposed to full prismatic shift. Here, we selectively investigated the effect of realignment on motor behaviour by means of a PA paradigm (the multiple-step PA) that allows to elude the development of strategic calibration. We tested for a specific cerebellar contribution to realignment by means of transcranial Direct Current Stimulation (tDCS) in healthy subjects. Confirming and expanding previous imaging and stimulation results, our study causally demonstrates cerebellar involvement in spatial realignment. Additionally, our results point to a possible contribution of the cerebellum in automatic online control. The role of a cortico-cerebellar network accounting for this results and possible clinical applications are proposed and discussed.

Towards a neuro-computational account of prism adaptation

Prism adaptation has a long history as an experimental paradigm used to investigate the functional and neural processes that underlie sensorimotor control. In the neuropsychology literature, prism adaptation behaviour is typically explained by reference to a traditional cognitive psychology framework that distinguishes putative functions, such as 'strategic control' versus 'spatial realignment'. This theoretical framework lacks conceptual clarity, quantitative precision and explanatory power. Here, we advocate for an alternative computational framework that offers several advantages: 1) an algorithmic explanatory account of the computations and operations that drive behaviour; 2) expressed in quantitative mathematical terms; 3) embedded within a principled theoretical framework (Bayesian decision theory, state-space modelling); 4) that offers a means to generate and test quantitative behavioural predictions. This computational framework offers a route towards mechanistic neurocognitive explanations of prism adaptation behaviour. Thus it constitutes a conceptual advance compared to the traditional theoretical framework. In this paper, we illustrate how Bayesian decision theory and state-space models offer principled explanations for a range of behavioural phenomena in the field of prism adaptation (e.g. visual capture, magnitude of visual versus proprioceptive realignment, spontaneous recovery and dynamics of adaptation memory). We argue that this explanatory framework can advance understanding of the functional and neural mechanisms that implement prism adaptation behaviour, by enabling quantitative tests of hypotheses that go beyond merely descriptive mapping claims that ‘brain area X is (somehow) involved in psychological process Y’.

High-speed polarized light microscopy for in situ, dynamic measurement of birefringence properties

A high-speed, quantitative polarized light microscopy (QPLM) instrument has been developed to monitor the optical slow axis spatial realignment during controlled medium to high strain rate experiments at acquisition rates up to 10 kHz. This high-speed QPLM instrument is implemented within a modified drop tower and demonstrated using polycarbonate specimens. By utilizing a rotating quarter wave plate and a high-speed camera, the minimum acquisition time to generate an alignment map of a birefringent specimen is 6.1 ms. A sequential analysis method allows the QPLM instrument to generate QPLM data at the high-speed camera imaging frequency 10 kHz. The obtained QPLM data is processed using a vector correlation technique to detect anomalous optical axis realignment and retardation changes throughout the loading event. The detected anomalous optical axis realignment is shown to be associated with crack initiation, propagation, and specimen failure in a dynamically loaded polycarbonate specimen. The work provides a foundation for detecting damage in biological tissues through local collagen fiber realignment and fracture during dynamic loading.