Local Deficits Research Articles

Diagnostic Accuracy of Contrast Enhanced Flair Magnetic Resonance Imaging in Diagnosis of Meningitis Taking Lumbar Puncture as Gold Standard

Objective: The objective of this article is to determine and compare the diagnostic accuracies of contrastenhanced FLAIR and T1W sequences of MRI brain in the detection of meningitis keeping lumbar puncture asgold standard.Study Design: Cross-sectional validation study.Place and Duration of Study: The study was carried out at Department of Diagnostic Radiology of POFHospital, Wah Cantt from 23 June 2019 to 22 March 2020.Materials and Methods: A total of 173 patients were included in the study by non-probability purposivesampling. Patients of age between 2-70 years, of either gender with suspected meningitis based on clinicalpresentation are included in our study. Patients in whom contrast enhanced MRI and lumbar puncture wascontraindicated, diagnosed patient of meningitis and non-consenting patients were excluded from this study.All patients received intravenous contrast medium gadolinium at rate of 0.2 ml/second. Post gadolinium T1Wand post gadolinium FLAIR images were acquired and evaluated by a consultant radiologist. Findings wererecorded on a prescribed performa. Patients were followed and results of lumbar puncture were collected fromlaboratory.Result: The mean age was 26.4±23.5 year ranging from 2 to 70 years. Out of 173 patients, 98 patients (56.6%)were male and 75 patients (43.4%) were female. Clinical presentations were as follows: poor feeding, irritabilityand lethargy 86 (49.7%), headache 137 (79.2%), nausea/vomiting 125 (72.3%), neck stiffness 89 (51.4%),altered level of consciousness 132 (76.3%), seizures 78 (45.1%) and local neurological deficit 45 (26%).Diagnostic accuracy of contrast enhanced MRI FLAIR in diagnosing meningitis taking lumbar puncture goldstandard showed sensitivity 91%, specificity 85%, PPV 87.6%, NPV 89.4% and diagnostic accuracy 88.4%.Diagnostic accuracy of contrast enhanced MRI T1W in the diagnosis of meningitis taking lumbar puncture goldstandard revealed sensitivity 60.2%, specificity 77.5%, PPV 75.6%, NPV 62.6% and diagnostic accuracy 68.2%.Conclusion: The sensitivity and specificity of post contrast FLAIR sequence is greater as compared to postcontrast T1W sequence to detect meningeal enhancement. Therefore, for all patients with suspicion ofmeningitis, post contrast FLAIR sequence should be added to MRI brain protocol as a routine sequence.How to cite this: Jawwad S, Gul N, Mehmood K, Iqbal B, Afzal K. Diagnostic Accuracy of Contrast Enhanced Flair Magnetic Resonance Imaging in Diagnosis of Meningitis Taking Lumbar Puncture as Gold Standard. Life and Science. 2022; 3(3): 120-126. doi: http://doi.org/10.37185/LnS.1.1.259

The role of mitochondria in the recovery of neurons after injury.

The role of mitochondria in the recovery of neurons after injury.

Energetics of intrinsic point defects and hydrogen in tungsten borides: a first-principles study

To understand the irradiation resistance and hydrogen (H) behavior in tungsten borides (W x B y ) in a burning plasma fusion environment, the energetics of intrinsic point defects and H in six stable ground state W borides, including W2B, WB, WB2, W2B5, WB3 and WB4, have been investigated using first-principles density functional theory calculations. The results show that the formation energies of interstitials and vacancies do not directly depend on the W and B content in W borides. However, the interaction between vacancies of a stoichiometric vacancy (SV) cluster in W x B y is related to the atomic ratio of B to W (y/x). The vacancies of a minimum-size SV cluster in W x B y are energetically repulsive for y/x ⩽ 1, while the vacancies energetically bind together for y/x larger than 1. The formation energy of B Frenkel pairs in each W boride is lower than that of W Frenkel pairs. Among the six evaluated W x B y compositions, WB has the highest and the lowest formation energy of H interstitials and H-vacancy complexes, respectively; however, these two energies in WB2 are in reverse order. The average H binding energies to single vacancies in WB and WB4 are comparable with that in W, while this binding energy in WB3 and WB2 is obviously higher or lower than in W, respectively. The diffusion activation energy of H in W borides is anisotropic. One dimensional (1D) diffusion of H in W2B, as well as 1D/2D diffusion in WB, W2B5, WB3 and WB4 are preferred at relatively low temperatures; however, three-dimensional diffusion of H is predicted in WB2. The diffusion activation energy of H generally increases with B content in W borides due to the increasing local charge deficit caused by strong B–B covalent bonds. This study is useful for evaluating the performance of W borides in a fusion environment.

0152 A functional role for global slow oscillations in major depressive disorder with hypersomnia

Abstract Introduction Sleep slow oscillations (SOs, 0.5-1.5Hz) during stages N2 and N3 sleep facilitate cortical communication and are important to the restorative properties of sleep. Spatiotemporal clustering analysis of SOs on the electrode manifold has identified 3 topographically distinct patterns of SOs: Frontal, Local, and Global. Global SOs are spatially widespread cortical events implicated in anterior-posterior long-range communication. However, their precise functional significance is not fully understood. Patients experiencing Major Depressive Disorder (MDD) with comorbid hypersomnia show local deficits in parieto-central slow wave activity, suggesting that frontally-initiated SOs are not propagating to parietal-central regions. Hypersomnolence in MDD may therefore be connected to insufficiently restorative sleep. Here, we retrospectively examine associations between Global SOs in N2 and N3 sleep and hypersomnia severity in healthy controls and MDD patients. Methods MDD patients with (n=22) and without (n=22) hypersomnia, and age-gender balanced healthy controls (n=22) underwent overnight polysomnography studies with 256-channel hdEEG. After detection of SOs, our previously developed classification method was applied retrospectively to all SOs in this dataset, including leveraging a k-means clustering algorithm naïve to the MDD/Hypersomnia label. Fractions of global SOs during stages N2 and N3 were compared across healthy controls and MDD patients. Finally, the fraction of global SOs occurring during the night was correlated against all subjects’ individual scores on the Hypersomnia Severity Index (HSI). Results Analysis of EEG data revealed pronounced, but not statistically significant deficits in global SOs during N3 sleep in MDD patients with comorbid hypersomnia. These deficits were significantly correlated with HSI when examining MDD patients together (Pearson’s r = -0.397, p<0.01). Conclusion Our findings suggest that MDD patients with higher hypersomnia severity experience more pronounced deficits in Global SOs. Given the importance of SOs for the restorative properties of sleep, it is possible that MDD patients with hypersomnia might incur an enhanced sleep need driven by the homeostatic cost of a deficit in Global SOs.. Future studies are necessary to investigate causal mechanisms underlying these findings. Support (If Any) American Sleep Medicine Foundation (76-JF-12), Brain and Behavior Research Foundation (19193), and NIMH (K23MH099234) to DTP.

Energy Transition: Approaches to the Formation of Research Agenda for Russian Science

The approaches to the formation of the agenda of scientific research on the transition to low-carbohydrate energy in the Russian Federation are considered. The analysis of technical, economic, environmental and political aspects of the problem of choosing priorities for the development of low-carbon energy and, accordingly, the choice of priorities for the organization of scientific research on energy transfer is carried out. The analysis of local energy deficits as the basis for setting the task of transition to the environmental agenda is carried out. The role of various energy carriers and their functions in the chains of generation, transportation, storage and consumption of energy is considered. It is concluded that the development oftechnologies for the capture, burial and processing of carbon dioxide and other greenhouse gases is the most promising for the Russian Federation. The main directions for the organization of scientific and technical research and expert-analytical support of political discussions on the directions of development of low-carbon energy are proposed.

Surgical Treatment of Spinal Metastatic Pheochromocytoma and Paraganglioma: A Single Institutional Cohort of 18 Patients.

Retrospective Cohort Study. To describe surgeries and treatment outcomes of metastatic pheochromocytomas and paragangliomas (PPGLs) on the spine. We reviewed a cohort of 18 patients with spinal PPGLs who were consecutively treated in our spinal center. Their clinical data was reviewed. The survival period and its relevant factors was then analyzed. The cohort included ten cases of pheochromocytomas and eight paragangliomas. The local pain and neurological deficits were the two most common symptoms. One third of the spinal PPGLs were diagnosed as functional tumors, arousing secondary hypertension. The imaging features were consistent with those of osteolytic lesions. The surgical strategies for the cohort included percutaneous vertebroplasty, neurological decompression and partial tumor resection, and total en-bloc resection. The postoperative courses were uneventful except 1 patient developed heart failure. The adjuvant therapies were implemented in 6 patients with 131I-MIBG, five with radiotherapy, two with chemotherapy, and 1 with target therapy. The median survival period was 39months, and the overall survival rate of 1year was 77.8% (14/18). The patients' Karnofsky performance scores were positively correlated with the survival period (P < .05). Surgery is indicated for intractable local pain and neurological impairment in the patients with spinal PPGLs. Palliative surgical strategies, including neurological decompression and partial tumor resection, could bring fair outcomes, especially for the patients in poor physical conditions.

Retinal ultrastructural, electrophysiological, and microvascular morphological outcomes in diabetic macular edema treated with intravitreal bevacizumab.

Investigation of retinal ultrastructural, electrophysiological, and microvascular morphological changes, as well as correlations between these changes and visual outcome in naïve diabetic macular edema (DME) patients after intravitreal bevacizumab therapy (IVBT). This prospective interventional study enrolled 31 DME patients' eyes treated with monthly IVBT for three months. Best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were measured, and fundus fluorescein angiography, optical coherence tomography (OCT), microperimetry, as well as optical coherence tomography angiography (OCTA) were performed before and after IVBT. Patients were grouped based on BCVA improvement after three consecutive IVBT: group 1: > 10 letters, group 2: ≤ 5 letters, and group 3: between 6 and 10 letters. Mean BCVA increased significantly from 34.2 to 39.9 letters (p < 0.001). Central macular thickness decreased significantly from 335.1 to 276.4μm (p < 0.001). Fixation stability, retinal sensitivity, and local deficit all improved significantly (p < 0.001 for all). There was no statistically significant change in IOP (p = 0.665). Although OCTA parameters did not change significantly, lower foveal avascular zone (FAZ) area, higher foveal vessel density 300μm area around FAZ and deep plexus vascular density were associated with highly improved BCVA, retinal sensitivity, and local deficit. Also, there were no significant intergroup differences in gender, age, baseline BCVA, HbA1c, IOP, phakic/pseudophakic lens ratio, concomitant hypertension, and superficial capillary plexus vascular density. IVBT was associated with significantly improved BCVA, retinal ultrastructural integrity, and electrophysiological patterns in naive DME patients. Improvements in retinal electrophysiology correlated with ultrastructural improvements, which could be predicted using OCTA.

A national quality improvement study identifying and addressing cancer screening deficits due to the COVID-19 pandemic.

Cancer-related deaths over the next decade are expected to increase due to cancer screening deficits associated with the coronavirus disease 2019 (COVID-19) pandemic. Although national deficits have been quantified, a structured response to identifying and addressing local deficits has not been widely available. The objectives of this report are to share preliminary data on monthly screening deficits in breast, colorectal, lung, and cervical cancers across diverse settings and to provide online materials from a national quality improvement (QI) study to help other institutions to address local screening deficits. This prospective, national QI study on Return-to-Screening enrolled 748 accredited cancer programs in the United States from April through June 2021. Local prepandemic and pandemic monthly screening test volumes (MTVs) were used to calculate the relative percent change in MTV to describe the monthly screening gap. The majority of facilities reported monthly screening deficits (colorectal cancer, 80.6% [n = 104/129]; cervical cancer, 69.0% [n = 20/29]; breast cancer, 55.3% [n = 241/436]; lung cancer, 44.6% [n = 98/220]). Overall, the median relative percent change in MTV ranged from -17.7% for colorectal cancer (interquartile range [IQR], -33.6% to -2.8%), -6.8% for cervical cancer (IQR, -29.4% to 1.7%), -1.6% for breast cancer (IQR, -9.6% to 7.0%), and 1.2% for lung cancer (IQR, -16.9% to 19.0%). Geographic differences were not observed. There were statistically significant differences in the percent change in MTV between institution types for colorectal cancer screening (P = .02). Cancer screening is still in need of urgent attention, and the screening resources made available online may help facilities to close critical gaps and address screenings missed in 2020. Question: How can the effects of the coronavirus disease 2019 pandemic on cancer screening be mitigated? When national resources were provided, including methods to calculate local screening deficits, 748 cancer programs promptly enrolled in a national Return-to-Screening study, and the majority identified local screening deficits, most notably in colorectal cancer. Using these results, 814 quality improvement projects were initiated with the potential to add 70,000 screening tests in 2021. Meaning: Cancer screening is still in need of urgent attention, and the online resources that we provide may help to close critical screening deficits.

Downregulation of the schizophrenia risk-gene Dgcr2 alters early microcircuit development in the mouse medial prefrontal cortex.

Alterations in the generation, migration and integration of different subtypes of neurons in the medial prefrontal cortex (mPFC) microcircuit could play an important role in vulnerability to schizophrenia. Using in vivo cell‐type specific manipulation of pyramidal neurons (PNs) progenitors, we aim to investigate the role of the schizophrenia risk‐gene DiGeorge Critical Region 2 (Dgcr2) on cortical circuit formation in the mPFC of developing mice. This report describes how Dgcr2 knock down in upper‐layer PNs impacts the functional maturation of PNs and interneurons (INs) in the mPFC. First, we demonstrate that Dgcr2 knock‐down disrupts laminar positioning, dendritic morphology and excitatory activity of upper‐layer PNs. Interestingly, inhibitory activity is also modified in Dgcr2 knock‐down PNs, suggesting a broader microcircuit alteration involving interneurons. Further analyses show that the histological maturation of parvalbumin (PV) INs is not dramatically impaired, thus implying that other INs subtypes might be at play in the reported microcircuit alteration. Overall, this study unravels how local functional deficits of the early postnatal development of the mPFC can be induced by Dgcr2 knock‐down in PNs.

EVALUATION OF SOME BREAD WHEAT GENOTYPES UNDER DIFFERENT ABIOTIC STRESSES

The current study was conducted at the Experimental Farm of Sakha Agricultural Research Station (31o06 N,30o 56 E) during the two growing seasons of 2017-2018 and 2018-2019 to evaluate sixteen genotypes of bread wheat, such as ten promising lines from the local breeding program and six local cultivars, under normal, water deficit, and soil salinity conditions. The genotypes were arranged in three experiments representing the growing conditions. The used design was a randomized complete block design with four replications. Results appeared that there was significant decrease in all studied characters as result of water deficit and soil salinity conditions compared to the normal one, except 1000-kernel weight which increased under water deficit conditions. The effect of genotypes x growing conditions interaction was significant for days to heading, days to maturity and grain yield in both seasons while it was only significant in the 1st season for number of spikes m-2 and 1000-kerenl weight. The mean comparisons indicated that Line 7, Line 10 and Line 9 had moderate values of grain yield under both water deficit and soil salinity stresses with low grain yield reduction under those conditions. Therefore, Line 7, Line 10 and Line 9 may be applied in breeding program to generate new recombination with good soil salinity and water deficit tolerance characteristics. Meanwhile, the three cultivars; Misr 3, Sakha 95 and Giza 171 exhibited the highest grain yield under the three conditions with lowest grain yield reduction under both water deficit and soil salinity conditions indicating their good ability to tolerant difficult growing conditions. Therefore, these cultivars can recommend to be grown under water deficit or salt affected soil conditions. These results may be helpful to plan appropriate selection strategies to improve grain yield under water deficit and soil salinity in wheat crop in Egypt.

Locally financed and outside financed regional fiscal multipliers

The size of regional fiscal multipliers determines the efficacy of fiscal stimulus, the costs of fiscal austerity and whether countercyclical fiscal policy is more effective at the federal or local level. This paper studies fiscal multipliers in regions of a monetary union—US states, Eurozone members, or countries with a hard exchange-rate peg—and how multipliers are affected by the way spending is financed: local deficit financing, local tax financing or outside financing (federal or foreign aid). I present analytical and quantitative government purchase and transfer multipliers using a New Keynesian model consistent with estimated transfer multipliers in Pennings (2021), focusing on the persistence of the fiscal shock. I find that at business-cycle frequencies, financing has little effect on impact multipliers: outside-financed multipliers are only about 0.07–0.16 larger than local deficit-financed multipliers. This suggests efforts to enable local countercyclical fiscal policy may be a partial substitute for greater fiscal centralization or foreign financing.

FINANCING THE GREENING OF ENTERPRISES IN INDUSTRIAL REGIONS OF UKRAINE IN THE CONTEXT OF SUSTAINABLE DEVELOPMENT

The work is devoted to the study of improving the environmental situation in industrial regions with metallurgical production in Ukraine. It was revealed that monitoring and purification of air, water environment and land resources requires immediate development and implementation of greening projects. This requires finding additional financial resources that are lacking in local budget deficits. To improve the quality of formation and use of local budgets, a method of monitoring the revenue side of local budgets is proposed, which consists in processing a set of data imported from monthly revenues and processed using predictive analytics tools. The methodology allows to identify significant and insignificant factors in a timely manner, including the environmental tax in the resulting factor - local budget revenues. With the development of analytical systems and the expansion of their application in the greening of industrial regions, the developed methodology will not lose its relevance. The developed methodology for monitoring the environmental tax and other taxes, fees and charges is aimed at identifying additional (indirect) sources of funding for greening projects in industrial regions, including metallurgical production. The method was tested on the revenues of local budgets of cities with metallurgical production – Zaporizhzhya, Dnipro for the period 2018-2020. The use of the methodology allowed to show that the revenues of the environmental tax are the most insignificant. It is also proposed to use the experience of developed countries in the mechanism of calculating the environmental tax in order to increase its amount.

Using Timescales of Deficit and Residence to Evaluate Near‐Bottom Dissolved Oxygen Variation in Coastal Seas

AbstractWe identify the local, vertical and lateral processes that cause bottom oxygen variation, and characterize timescales for each process using oxygen budget analysis based on a coupled physical‐biogeochemical model for the coastal seas in east China. Local oxygen deficit often occurs in the summer season due to the faster local consumption than the vertical replenishment in seasonal timescale. Lateral transport of oxygen‐rich ambient water replenishes local deficit of bottom dissolved oxygen. Competition between local deficit and lateral exchange determines seasonal hypoxia formation and sustainment. Short local consumption timescale is favorable for hypoxia formation, and transient hypoxia often forms when the local deficit and lateral exchange processes act on comparable timescales, such as the East China Sea in which the bottom hypoxia usually lasts for days. Extremely long lateral exchange timescale suggests that dissolved oxygen variation is predominantly controlled by local processes, and short local consumption timescale often causes increasingly severe seasonal hypoxia until the onset of the relaxation of local deficit, such as the bottom hypoxia in the Bohai Sea. Using these timescales to evaluate local deficit relative to vertical and lateral residence time and their variability is a convenient and potentially powerful general mechanistic framework to evaluate strategies to mitigate coastal hypoxia worldwide.

The system of indicators of the financial stability of the local budget as a component of the assessment of the competitive immunity of the region

The article examines the essence of competitive immunity and gives the main stages of evaluating the competitive immunity of the region. There are three blocks for assessing the competitive immunity of the region: information and digital approach; information and digital technologies; value and reputation management. In accordance with the selected blocks, the objects of management influence necessary for assessing the competitive immunity of the region and bringing it to sustainable functioning are defined, namely: production sustainability, financial sustainability, socio-economic sustainability, informational and psychological sustainability, market sustainability, sustainable innovative development, growth of business value, balanced innovative infrastructure and reputation of the region. For one of the important objects of managerial influence, namely, financial stability, a system of indicators of a comprehensive analysis of the financial stability of the local budget as a component of competitive immunity is proposed, which should be considered in three groups: analysis of the balance of the local budget, analysis of financial stability and analysis of budget efficiency. The proposed ratio complex consists of twelve indicators, namely: coefficient of budget coverage, coefficient of budget sustainability, coefficient of general tax stability, coefficient of cost coverage by interbudgetary transfers, coefficient of budget dependence, coefficient of tax independence, coefficient of stability of the income base, the share of equalization grants in the total amount of transfers, local budget deficit ratio, coefficient of budgetary efficiency, coefficient of budgetary support, indicator of stability of the revenue part of the budget. The essence and normative values of the proposed indicators were considered. Within the framework of the proposed approach, the components of the integral indicator of the financial stability of the local budget are considered. The essence and algorithm of the work of Kohonen's neural networks with the aim of its further use for the segmentation of regions based on indicators of financial stability of regions are given.

Современные особенности развития комфортной городской среды в малых городах Калининградской области

Given the issue of balanced socio-economic development of the entire territory of the Ka­liningrad region, an important task is to improve the quality of life in small towns in the re­gion, as they serve as supporting elements for the regional settlement frame. Attracting feder­al and extrabudgetary funds could be seen as an effective tool in the context of a local budget deficit. To date, improving the quality of urban spaces has been possible due to participation in the all-Russian competition for the best projects for creating a comfortable urban environ­ment, which has been held since 2018. Having accumulated competencies in working on com­petitive project applications, and participating in numerous cross-border cooperation pro­grams, Kaliningrad group actively and very effectively join in this competition, which has already changed the quality of the urban environment. Many small towns of the Kaliningrad region are on the list of federal leaders among the places with the most comfortable urban en­vironment. This circumstance directly improves the possibilities of such cities in attracting investors, maintaining high-quality labor resources and the possibility of expanding their own regional socio-economic specialization.

China’s Local Government Debt: The Grand Bargain

China’s rapidly growing local government debt problem has long been recognized by foreign observers as a risk, but inside China, only recently was this problem called out as alarming. Why has local government debt been allowed to grow with little direct intervention from central authorities? We argue that it has much to do with a “grand bargain” between the central government and localities during the 1994 fiscal recentralization reform. While much scholarly attention has been paid to the consequences of the 1994 reform that left localities with a tremendous fiscal gap, our findings show that Beijing in fact gave localities the green light to create new backdoor financing institutions that counteracted the impact of fiscal recentralization. In essence, these institutions were the quid pro quo offered to localities to sustain their incentive for local state-led growth after 1994. The bargain worked, and growth continued. The drawback, however, was that China’s economic growth has been accompanied by the accumulation of local government debt with little transparency and central control. When the global financial crisis slowed growth, and local deficits and debts spiked, Beijing began to shut down backdoor financing and opened front-door options that were transparent and under the control of national authorities—but with limited success. In the wake of COVID-19, the question is whether the pendulum will swing back toward more tolerance of local debt for the sake of economic growth.

Numerical investigation and assessment of flamelet-based models for the prediction of pulverized solid fuel homogeneous ignition and combustion

The homogeneous ignition and volatile combustion of pulverized solid fuel in single-particle and particle group configurations were studied numerically in a laminar flat flame burner. Simulations with increasing particle streams were performed to investigate the influence of the interactions in particle groups on homogeneous ignition and combustion. An extensive set of simulations are conducted considering models with different levels of detail for both the gas-phase and solid fuel chemistry. The reference simulations employ the chemical percolation devolatilization model coupled with a detailed chemistry model for gas-phase reactions. The particle-fluid interactions were modeled with a fully coupled Eulerian-Lagrangian framework. Increased ignition delay times for higher particle streams were successfully validated against available experimental measurements. Furthermore, the transition from single-particle ignition to a conically shaped volatile flame with suppressed reactions near the flame base in particle group combustion was observed in both experiments and simulations. The subsequent detailed investigations revealed that the increased heat transfer to particles and, therefore, lower gas temperature for higher particle number densities together with the local oxygen depletion are the primary reasons for this transition. Based on the reference simulation, different simplified model combinations were assessed. The systematic model reduction investigation started with assessing the fixed volatile composition as a required assumption for flamelet models. Finally, the effects of gas-phase chemistry and different simple devolatilization models on ignition and combustion chemistry were studied. Overall, all model combinations provide reasonable predictions of volatile combustion with minor local deficits in the studied conditions.

Party alternation and fiscal performance—evidence from Taiwan’s local government

This study aims to explore whether party alternation in local mayoral elections might have any influence on the local fiscal deficit in each of the four years after such elections take place in Taiwan. The results of five local mayoral elections for the 21 counties/cities in 1989, 1993, 1997, 2001 and 2005, respectively, as well as three indicators of the fiscal deficit for the 21 counties and cities from 1990 to 2009 are employed to estimate the spatial econometric model. The primary finding of this study is that after using instrument variable to conquer the endogeneity problem, party alternation making counties to have new mayors of new ruling parties cannot mitigate the fiscal deficit in any years after the election, instead will tend to aggravate the local fiscal deficit in the third and fourth years after the election that is consistent with the theory of political budget cycle.

Forgery Detection in Digital Images by Multi-Scale Noise Estimation.

A complex processing chain is applied from the moment a raw image is acquired until the final image is obtained. This process transforms the originally Poisson-distributed noise into a complex noise model. Noise inconsistency analysis is a rich source for forgery detection, as forged regions have likely undergone a different processing pipeline or out-camera processing. We propose a multi-scale approach, which is shown to be suitable for analyzing the highly correlated noise present in JPEG-compressed images. We estimate a noise curve for each image block, in each color channel and at each scale. We then compare each noise curve to its corresponding noise curve obtained from the whole image by counting the percentage of bins of the local noise curve that are below the global one. This procedure yields crucial detection cues since many forgeries create a local noise deficit. Our method is shown to be competitive with the state of the art. It outperforms all other methods when evaluated using the MCC score, or on forged regions large enough and for colorization attacks, regardless of the evaluation metric.

Analysis of correlations between local geographic atrophy growth rates and local OCT angiography-measured choriocapillaris flow deficits.

The purpose of this study is to quantitatively assess correlations between local geographic atrophy (GA) growth rates and local optical coherence tomography angiography (OCTA)-measured choriocapillaris (CC) flow deficits. Thirty-eight eyes from 27 patients with GA secondary to age-related macular degeneration (AMD) were imaged with a commercial 1050 nm swept-source OCTA instrument at 3 visits, each separated by ∼6 months. Pearson correlations were computed between local GA growth rates, estimated using a biophysical GA growth model, and local OCTA CC flow deficit percentages measured along the GA margins of the baseline visits. The p-values associated with the null hypothesis of no Pearson correlation were estimated using a Monte Carlo permutation scheme that incorporates the effects of spatial autocorrelation. The null hypothesis (Pearson's ρ = 0) was rejected at a Benjamini-Hochberg false discovery rate of 0.2 in 15 of the 114 visit pairs, 11 of which exhibited positive correlations; even amongst these 11 visit pairs, correlations were modest (r in [0.30, 0.53]). The presented framework appears well suited to evaluating other potential imaging biomarkers of local GA growth rates.