Artigos de revistas: "Hamilton-connectivity"

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Hayat, Sakander, Asad Khan, Suliman Khan e Jia-Bao Liu. "Hamilton Connectivity of Convex Polytopes with Applications to Their Detour Index". Complexity 2021 (23 de janeiro de 2021): 1–23. http://dx.doi.org/10.1155/2021/6684784.

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A connected graph is called Hamilton-connected if there exists a Hamiltonian path between any pair of its vertices. Determining whether a graph is Hamilton-connected is an NP-complete problem. Hamiltonian and Hamilton-connected graphs have diverse applications in computer science and electrical engineering. The detour index of a graph is defined to be the sum of lengths of detours between all the unordered pairs of vertices. The detour index has diverse applications in chemistry. Computing the detour index for a graph is also an NP-complete problem. In this paper, we study the Hamilton-connectivity of convex polytopes. We construct three infinite families of convex polytopes and show that they are Hamilton-connected. An infinite family of non-Hamilton-connected convex polytopes is also constructed, which, in turn, shows that not all convex polytopes are Hamilton-connected. By using Hamilton connectivity of these families of graphs, we compute exact analytical formulas of their detour index.

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Hayat, Sakander, Muhammad Yasir Hayat Malik, Ali Ahmad, Suliman Khan, Faisal Yousafzai e Roslan Hasni. "On Hamilton-Connectivity and Detour Index of Certain Families of Convex Polytopes". Mathematical Problems in Engineering 2021 (17 de julho de 2021): 1–18. http://dx.doi.org/10.1155/2021/5553216.

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A convex polytope is the convex hull of a finite set of points in the Euclidean space ℝ n . By preserving the adjacency-incidence relation between vertices of a polytope, its structural graph is constructed. A graph is called Hamilton-connected if there exists at least one Hamiltonian path between any of its two vertices. The detour index is defined to be the sum of the lengths of longest distances, i.e., detours between vertices in a graph. Hamiltonian and Hamilton-connected graphs have diverse applications in computer science and electrical engineering, whereas the detour index has important applications in chemistry. Checking whether a graph is Hamilton-connected and computing the detour index of an arbitrary graph are both NP-complete problems. In this paper, we study these problems simultaneously for certain families of convex polytopes. We construct two infinite families of Hamilton-connected convex polytopes. Hamilton-connectivity is shown by constructing Hamiltonian paths between any pair of vertices. We then use the Hamilton-connectivity to compute the detour index of these families. A family of non-Hamilton-connected convex polytopes has also been constructed to show that not all convex polytope families are Hamilton-connected.

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Alspach, Brian, e Jiping Liu. "On the Hamilton connectivity of generalized Petersen graphs". Discrete Mathematics 309, n.º 17 (setembro de 2009): 5461–73. http://dx.doi.org/10.1016/j.disc.2008.12.016.

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Fan, Jianxi. "Hamilton-connectivity and cycle-embedding of the Möbius cubes". Information Processing Letters 82, n.º 2 (abril de 2002): 113–17. http://dx.doi.org/10.1016/s0020-0190(01)00256-3.

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Hu, Zhiquan, Feng Tian e Bing Wei. "Hamilton connectivity of line graphs and claw-free graphs". Journal of Graph Theory 50, n.º 2 (2005): 130–41. http://dx.doi.org/10.1002/jgt.20099.

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Chen, Yaojun, Feng Tian e Bing Wei. "Hamilton-connectivity of 3-domination-critical graphs with α⩽δ". Discrete Mathematics 271, n.º 1-3 (setembro de 2003): 1–12. http://dx.doi.org/10.1016/s0012-365x(02)00876-2.

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Liao, Lifang, Liulu Zhang, Jun Lv, Yingchun Liu, Jiliang Fang, Peijing Rong e Yong Liu. "Transcutaneous Electrical Cranial-Auricular Acupoint Stimulation Modulating the Brain Functional Connectivity of Mild-to-Moderate Major Depressive Disorder: An fMRI Study Based on Independent Component Analysis". Brain Sciences 13, n.º 2 (6 de fevereiro de 2023): 274. http://dx.doi.org/10.3390/brainsci13020274.

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Evidence has shown the roles of taVNS and TECS in improving depression but few studies have explored their synergistic effects on MDD. Therefore, the treatment responsivity and neurological effects of TECAS were investigated and compared to escitalopram, a commonly used medication for depression. Fifty patients with mild-to-moderate MDD (29 in the TECAS group and 21 in another) and 49 demographically matched healthy controls were recruited. After an eight-week treatment, the outcomes of TECAS and escitalopram were evaluated by the effective rate and reduction rate based on the Montgomery–Asberg Depression Rating Scale, Hamilton Depression Rating Scale, and Hamilton Anxiety Rating Scale. Altered brain networks were analyzed between pre- and post-treatment using independent component analysis. There was no significant difference in clinical scales between TECAS and escitalopram but these were significantly decreased after each treatment. Both treatments modulated connectivity of the default mode network (DMN), dorsal attention network (DAN), right frontoparietal network (RFPN), and primary visual network (PVN), and the decreased PVN–RFPN connectivity might be the common brain mechanism. However, there was increased DMN–RFPN and DMN–DAN connectivity after TECAS, while it decreased in escitalopram. In conclusion, TECAS could relieve symptoms of depression similarly to escitalopram but induces different changes in brain networks.

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Liu, Donglin, Chunxiang Wang e Shaohui Wang. "Hamilton-connectivity of Interconnection Networks Modeled by a Product of Graphs". Applied Mathematics and Nonlinear Sciences 3, n.º 2 (7 de dezembro de 2018): 419–26. http://dx.doi.org/10.21042/amns.2018.2.00032.

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AbstractThe product graph Gm *Gp of two given graphs Gm and Gp, defined by J.C. Bermond et al.[J Combin Theory, Series B 36(1984) 32-48] in the context of the so-called (Δ,D)-problem, is one interesting model in the design of large reliable networks. This work deals with sufficient conditions that guarantee these product graphs to be hamiltonian-connected. Moreover, we state product graphs for which provide panconnectivity of interconnection networks modeled by a product of graphs with faulty elements.

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Chen, Yaojun, Feng Tian e Yunqing Zhang. "Hamilton-connectivity of 3-Domination Critical Graphs with α=δ+ 2". European Journal of Combinatorics 23, n.º 7 (outubro de 2002): 777–84. http://dx.doi.org/10.1006/eujc.2002.0603.

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Nikoghosyan, Zh G. "Disconnected Forbidden Subgraphs, Toughness and Hamilton Cycles". ISRN Combinatorics 2013 (10 de março de 2013): 1–4. http://dx.doi.org/10.1155/2013/673971.

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In 1974, Goodman and Hedetniemi proved that every 2-connected -free graph is hamiltonian. This result gave rise many other conditions for Hamilton cycles concerning various pairs and triples of forbidden connected subgraphs under additional connectivity conditions. In this paper we investigate analogous problems when forbidden subgraphs are disconnected which affects more global structures in graphs such as tough structures instead of traditional connectivity structures. In 1997, it was proved that a single forbidden connected subgraph in 2-connected graphs can create only a trivial class of hamiltonian graphs (complete graphs) with . In this paper we prove that a single forbidden subgraph can create a non trivial class of hamiltonian graphs if is disconnected: every -free graph either is hamiltonian or belongs to a well defined class of non hamiltonian graphs; every 1-tough -free graph is hamiltonian. We conjecture that every 1-tough -free graph is hamiltonian and every 1-tough -free graph is hamiltonian.

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Chen, Yaojun, T. C. Edwin Cheng e C. T. Ng. "Hamilton-connectivity of 3-domination critical graphs with α=δ+1⩾5". Discrete Mathematics 308, n.º 7 (abril de 2008): 1296–307. http://dx.doi.org/10.1016/j.disc.2007.03.075.

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Broersma, Hajo, Jiří Fiala, Petr A. Golovach, Tomáš Kaiser, Daniël Paulusma e Andrzej Proskurowski. "Linear-Time Algorithms for Scattering Number and Hamilton-Connectivity of Interval Graphs". Journal of Graph Theory 79, n.º 4 (28 de outubro de 2014): 282–99. http://dx.doi.org/10.1002/jgt.21832.

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Zuo, Ting, Heng Wei e Na Chen. "Incorporating Low-Stress Bicycling Connectivity into Expanded Transit Service Coverage". Transportation Research Record: Journal of the Transportation Research Board 2675, n.º 4 (abril de 2021): 79–89. http://dx.doi.org/10.1177/0361198121998956.

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The speed advantage in bicycling over walking is believed to ease first-and-last mile (F&LM) travel and expand transit service coverage. To quantitatively investigate the potential effect of using bicycle as a F&LM connector, the paper measures and compares the impacts of walking and bicycling F&LM access on transit service coverage. In the estimation of transit service coverage, F&LM travel decay functions representing the attractiveness of public transit that declines with increasing walking/biking time to access transit facilities and the spatial boundaries of transit catchment areas are developed using GPS trajectory data collected from the latest Cincinnati Household Travel Survey in Hamilton County, Ohio. Level of traffic stress is used to evaluate the bicycle suitability of streets and bike network connectivity. Based on the F&LM distance decay functions and low-stress bike network connectivity, the transit service coverage area as well as the transit-served population and employment in Hamilton County, Ohio, are estimated. Results show that more population can reach transit services and therefore employment by bicycling than walking. Meanwhile, disadvantaged groups, that is, low-income and zero-car population, can be better served by transit if using bicycle as the F&LM connector. In addition, low-stress bicycling connectivity is a significant factor determining the bicycle-transit service coverage, and a well-connected low-stress bike network with quality bikeways is crucial to guaranteeing that. These findings can be used as references to assist planners in their decision-making process to achieve better mobility and accessibility.

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米, 晶. "The Hamilton-Connectivity with the Sum Degree of Subgraph in Claw-Free Graphs". Advances in Applied Mathematics 03, n.º 01 (2014): 8–16. http://dx.doi.org/10.12677/aam.2014.31002.

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Forcan, Jovana, e Mirjana Mikalački. "Spanning Structures in Walker–Breaker Games". Fundamenta Informaticae 185, n.º 1 (18 de março de 2022): 83–97. http://dx.doi.org/10.3233/fi-222104.

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We study the biased (2 : b) Walker–Breaker games, played on the edge set of the complete graph on n vertices, Kn. These games are a variant of the Maker–Breaker games with the restriction that Walker (playing the role of Maker) has to choose her edges according to a walk. We look at the two standard graph games – the Connectivity game and the Hamilton Cycle game and show that Walker can win both games even when playing against Breaker whose bias is of the order of magnitude n/ ln n.

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Yang, Rui, Hongbo Zhang, Xiaoping Wu, Junle Yang, Mingyue Ma, Yanjun Gao, Hongsheng Liu e Shengbin Li. "Hypothalamus-Anchored Resting Brain Network Changes before and after Sertraline Treatment in Major Depression". BioMed Research International 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/915026.

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Sertraline, one of the oldest antidepressants, remains to be the most efficacious treatment for depression. However, major depression disorder (MDD) is characterized by altered emotion processing and deficits in cognitive control. In cognitive interference tasks, patients with MDD have shown excessive hypothalamus activity. The purpose of this study was to examine the effects of antidepressant treatment (sertraline) on hypothalamus-anchored resting brain circuitry. Functional magnetic resonance imaging was conducted on depressed patients(n=12)both before and after antidepressant treatment. After eight weeks of antidepressant treatment, patients with depression showed significantly increased connectivity between the hypothalamus and dorsolateral prefrontal cortex, orbitofrontal cortex, anterior cingulate cortex, insula, putamen, caudate, and claustrum. By contrast, decreased connectivity of the hypothalamus-related areas was primarily located in the inferior frontal gyrus, medial frontal gyrus, cingulated gyrus, precuneus, thalamus, and cerebellum. After eight weeks of antidepressant therapy, 8 out of the 12 depressed subjects achieved 70% reduction or better in depressive symptoms, as measured on the Hamilton depression rating scale. Our findings may infer that antidepressant treatment can alter the functional connectivity of the hypothalamus resting brain to achieve its therapeutic effect.

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Sabir, Eminjan, e Elkin Vumar. "Spanning Connectivity of the Power of a Graph and Hamilton-Connected Index of a Graph". Graphs and Combinatorics 30, n.º 6 (4 de setembro de 2013): 1551–63. http://dx.doi.org/10.1007/s00373-013-1362-4.

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Zheng, Wei, e Li-gong Wang. "The Hamilton-Connectivity with the Degree Sum of Non-adjacent Subgraphs of Claw-free Graphs". Acta Mathematicae Applicatae Sinica, English Series 35, n.º 3 (julho de 2019): 580–90. http://dx.doi.org/10.1007/s10255-019-0835-5.

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Espana, Lezlie, William McCuddy, Lindsay Nelson, Birn Rasmus, Andrew Mayer e Timothy Bradley Meier. "Association of acute depressive symptoms and functional connectivity in emotional processing regions following sport-related concussion". Neurology 91, n.º 23 Supplement 1 (4 de dezembro de 2018): S15.1—S15. http://dx.doi.org/10.1212/01.wnl.0000550600.65611.23.

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Few studies have examined the physiologic correlates of depressive symptoms following sport-related concussion (SRC), despite the prevalence of these symptoms following brain injury. We hypothesized that concussed athletes would have disrupted resting-state functional connectivity in emotional processing regions compared to controls, and that this disruption would be associated with greater post-concussion symptoms of depression. Forty-three concussed athletes at approximately 1 day (N = 34), 1 week (N = 34), and 1 month (N = 30) post-concussion were evaluated along with 51 healthy athletes assessed at a single visit. Resting-state fMRI was collected on a 3T GE scanner (TR = 2s); depressive symptoms were assessed using the Hamilton Rating Scale for Depression (HAM-D). Emotional processing regions of interest (ROI) were defined using an automated meta-analysis of brain regions associated with the term “emotion”. Fisher-Z transformed correlations were calculated between each ROI. A multivariate approach assessed connectivity by analyzing ROI as simultaneous response variables. Concussed athletes had significantly higher depressive symptoms relative to controls at all time points but showed partial recovery by 1-month post-concussion relative to earlier visits (p's< 0.05). Functional connectivity did not differ between controls and concussed athletes at 1 day or one-week post-concussion. However, concussed athletes had significantly different connectivity in regions associated with emotional processing at 1 month relative to 1 day post-concussion (p = 0.002), and relative to controls (p = 0.003). Follow-up analyses showed that increased connectivity between attention and default mode networks at 1-month post-concussion was common across both analyses. In addition, functional connectivity of emotional processing regions was significantly associated with depressive symptoms at 1 day (p = 0.003) and one-week post-concussion (p = 7 × 10-8), with greater HAM-D scores correlating with decreased connectivity between attention and default mode networks. These results suggest that intrinsic connectivity between default mode and attention regions following SRC may be compensatory in nature.

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Ouyang, Xuan, Yicheng Long, Zhipeng Wu, Dayi Liu, Zhening Liu e Xiaojun Huang. "Temporal Stability of Dynamic Default Mode Network Connectivity Negatively Correlates with Suicidality in Major Depressive Disorder". Brain Sciences 12, n.º 9 (17 de setembro de 2022): 1263. http://dx.doi.org/10.3390/brainsci12091263.

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Previous studies have demonstrated that the suicidality in patients with major depressive disorder (MDD) is related to abnormal brain functional connectivity (FC) patterns. However, little is known about its relationship with dynamic functional connectivity (dFC) based on the assumption that brain FCs fluctuate over time. Temporal stabilities of dFCs within the whole brain and nine key networks were compared between 52 MDD patients and 21 age, sex-matched healthy controls (HCs) using resting-state functional magnetic resonance imaging and temporal correlation coefficients. The alterations in MDD were further correlated with the scores of suicidality item in the Hamilton Rating Scale for Depression (HAMD). Compared with HCs, the MDD patients showed a decreased temporal stability of dFC as indicated by a significantly decreased temporal correlation coefficient at the global level, as well as within the default mode network (DMN) and subcortical network. In addition, temporal correlation coefficients of the DMN were found to be significantly negatively correlated with the HAMD suicidality item scores in MDD patients. These results suggest that MDD may be characterized by excessive temporal fluctuations of dFCs within the DMN and subcortical network, and that decreased stability of DMN connectivity may be particularly associated with the suicidality in MDD.

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Harrington, Y., M. Paolini, V. Bettonagli, F. Colombo, S. Poletti, R. Zanardi e F. Benedetti. "Resting State Functional Connectivity is Associated With Treatment Response in Major Depression: A Real World Study". European Psychiatry 66, S1 (março de 2023): S606—S607. http://dx.doi.org/10.1192/j.eurpsy.2023.1266.

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IntroductionMajor depressive disorder (MDD) is largely considered the most prevalent psychiatric disorder worldwide. Despite its domineering presence, effective treatment for many individuals remains elusive. Investigation into relevant biological markers, specifically neuroimaging correlates, of MDD and treatment response have gained traction in recent years; however, findings are still inconsistent.ObjectivesIn this study, we aimed to investigate the resting state functional connectivity patterns associated with treatment response in MDD inpatients in a real world setting.MethodsForty-three inpatients suffering from a major depressive episode were recruited from the psychiatric ward at IRCCS San Raffaele Hospital in Milan, Italy. Symptom severity was assessed via the 21-item Hamilton Depression Rating Scale (HDRS). The percentage of decrease in HDRS scores from admission to discharge was then calculated with the formula [(HDRS admission – HDRS discharge) * 100] / HDRS admission. All patients underwent a 3T MRI scan within one week of admission to acquire resting-state fMRI images, which included 200 sequential T2*-weighted volumes. Images were preprocessed using the CONN toolbox, running within Statistical Parametric Mapping (SPM 12). Preprocessing was performed according to a standard pipeline. A voxel-wise metric, intrinsic connectivity contrast (ICC), was implemented to explore the global resting state functional connectivity (rs-FC) patterns associated with treatment response. ICC-derived maps were then entered in the second-level analyses to examine the effect of the percentage of HDRS decrease, including age, sex, admission HDRS score, duration of hospitalization, and antidepressant dose equivalents as nuisance covariates.ResultsWe found that the percentage of HDRS decrease after treatment predicted rs-FC. ICC analysis identified 2 clusters where changes in HDRS scores were significantly associated with rs-FC, with increased connectivity in the supramarginal gyrus (pFDR = 0.002) and decreased connectivity in the amygdala and parahippocampal gyrus (pFDR = 0.047).ConclusionsOur results suggest that altered connectivity of the supramarginal gyrus, amygdala and parahippocampal gyrus is related to antidepressant treatment response. Given that these brain areas are implicated in emotional processing and mood, it is conceivable that a better integrity of brain connectivity may facilitate treatment response in major depression.Disclosure of InterestNone Declared

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Du, Yi, Jingjie Zhao, Yongzhi Wang, Yu Han, Ligang Deng, Hongxiao Jia, Yuan Zhou, Joyce Su e Li Li. "Brain Functional Differences in Drug-Naive Major Depression with Anxiety Patients of Different Traditional Chinese Medicine Syndrome Patterns: A Resting-State fMRI Study". Evidence-Based Complementary and Alternative Medicine 2020 (18 de fevereiro de 2020): 1–9. http://dx.doi.org/10.1155/2020/7504917.

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Major depressive disorder (MDD), especially combined with anxiety, has a high incidence and low detection rate in China. Literature has shown that patients under major depression with anxiety (MDA) are more likely to nominate a somatic, rather than psychological, symptom as their presenting complaint. In the theory of Traditional Chinese Medicine (TCM), clinical symptoms of MDD patients are mainly categorized into two different syndrome patterns: Deficiency and Excess. We intend to use resting-state functional magnetic resonance imaging (rs-fMRI) to investigate their brain functional differences and hopefully to find their brain function mechanism. For our research, 42 drug-naive MDA patients were divided into two groups (21 for Deficiency and 21 for Excess), with an additional 19 unaffected participants in the normal control (NC) group. We took Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Scale (HAMA), and brain fMRI scan for each group and analyzed the data. We first used Degree Centrality (DC) to map the functional differences in brain regions, utilized these regions as seed points, and used a seed-based functional connectivity (FC) analysis to identify the specific functional connection between groups. The Deficiency group was found to have higher HAMD scores, HAMA scores, and HAMD somatic factor than the Excess group. In the DC analysis, significant decreases were found in the right precuneus of both the Deficiency and Excess groups compared to the NC group. In the FC analysis, the right precuneus showed significant decreased network connectivity with the bilateral cuneus, as well as the right lingual gyrus in the Deficiency group when compared to the NC group and the Excess group. Through our research, it was found that precuneus dysfunction may have a relationship with MDA and Deficiency patients have more severe physical and emotional symptoms, and we realized that a larger sample size and multiple brain mode observations were needed in further research.

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Cieri, Filippo, Roberto Esposito, Nicoletta Cera, Valentina Pieramico, Armando Tartaro e Massimo di Giannantonio. "Late-Life Depression: Modifications of Brain Resting State Activity". Journal of Geriatric Psychiatry and Neurology 30, n.º 3 (30 de março de 2017): 140–50. http://dx.doi.org/10.1177/0891988717700509.

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Late-life depression (LLD) is a common emotional and mental disability in the elderly population characterized by the presence of depressed mood, the loss of interest or pleasure in daily activities, and other depression symptoms. It has a serious effect on the quality of life of elderly individuals and increases their risk of developing physical and mental diseases. It is an important area of research, given the growing elderly population. Brain functional connectivity modifications represent one of the neurobiological biomarker for LLD even if to date remains poorly understood. In our study, we enrolled 10 elderly patients with depressive symptoms compared to 11 age-matched healthy controls. All participants were evaluated by means of neuropsychological tests and underwent the same functional magnetic resonance imaging (fMRI) protocol to evaluate modifications of brain resting state functional connectivity. Between-group differences were observed for the Geriatric Depression Scale and Hamilton Depression Rating Scale, with higher scores for patients with LLD. Voxel-wise, 1-way analysis of variance revealed between-group differences in left frontoparietal network (lFPN) and sensory motor network (SMN): Increased intrinsic connectivity in the LLD group was observed in the left dorsolateral prefrontal cortex and in the left superior parietal lobule of the lFPN and increased intrinsic connectivity in the LLD group was observed in the bilateral primary somatosensory cortex of the SMN. Our findings support the use of resting state fMRI as a potential biomarker for LLD; even if to confirm the relationship between brain changes and the pathophysiology of LLD, longitudinal neuroimaging studies are required.

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Jeong, Won-Ki, P. Thomas Fletcher, Ran Tao e Ross Whitaker. "Interactive Visualization of Volumetric White Matter Connectivity in DT-MRI Using a Parallel-Hardware Hamilton-Jacobi Solver". IEEE Transactions on Visualization and Computer Graphics 13, n.º 6 (novembro de 2007): 1480–87. http://dx.doi.org/10.1109/tvcg.2007.70571.

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Park, Junha, Taekwan Kim, Minah Kim, Tae Young Lee e Jun Soo Kwon. "Functional Connectivity of the Striatum as a Neural Correlate of Symptom Severity in Patient with Obsessive-Compulsive Disorder". Psychiatry Investigation 17, n.º 2 (25 de fevereiro de 2020): 87–95. http://dx.doi.org/10.30773/pi.2019.0206.

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Objective It is well established that the cortico-striato-thalamo-cortical (CSTC) circuit is implicated in the pathophysiology of obsessive- compulsive disorder (OCD). However, reports on corticostriatal functional connectivity (FC) in OCD have been inconsistent due to the structural and functional heterogeneity of the striatum. Therefore, in the present study, we investigated corticostriatal FC using a fine 12-seed striatal parcellation to overcome this heterogeneity and discover the neural correlates of symptoms in OCD patients.Methods We recruited 23 OCD patients and 23 healthy controls (HCs). Whole-brain FC based on striatal seeds was examined using resting-state functional magnetic resonance imaging data and compared across OCD patients and HCs. We conducted correlation analysis between FCs of striatal subregions with significant group differences and symptom severity scores on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Hamilton Rating Scale for Depression, and Hamilton Rating Scale for Anxiety (HAM-A).Results Compared to HCs, patients demonstrated increased FC of the dorsal caudal putamen and ventral rostral putamen (VRP) with several cortical regions, such as the intracalcarine cortex, inferior frontal gyrus, supramarginal/angular gyrus (SMG/AG), and postcentral gyrus (PCG). Furthermore, FC between the VRP and SMG/AG and between the VRP and PCG was negatively correlated with scores on the Y-BOCS compulsive subscale and the HAM-A, respectively.Conclusion These findings suggest that striatal subregions have strengthened FC with extensive cortical regions, which may reflect neural correlates of compulsive and anxious symptoms in OCD patients. These results contribute to an improved understanding of OCD pathophysiology by complementing the current evidence regarding striatal FC.

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Bai, Tongjian, Qiang Wei, Wen Xie, Anzhen Wang, Jiaojian Wang, Gong-Jun JI, Kai Wang e Yanghua Tian. "Hippocampal-subregion functional alterations associated with antidepressant effects and cognitive impairments of electroconvulsive therapy". Psychological Medicine 49, n.º 08 (19 de setembro de 2018): 1357–64. http://dx.doi.org/10.1017/s0033291718002684.

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AbstractBackgroundElectroconvulsive therapy (ECT), an effective antidepressive treatment, is frequently accompanied by cognitive impairment (predominantly memory), usually transient and self-limited. The hippocampus is a key region involved in memory and emotion processing, and in particular, the anterior-posterior hippocampal subregions has been shown to be associated with emotion and memory. However, less is known about the relationship between hippocampal-subregion alterations following ECT and antidepressant effects or cognitive impairments.MethodsResting-state functional connectivity (RSFC) based on the seeds of hippocampal subregions were investigated in 45 pre- and post-ECT depressed patients. Structural connectivity between hippocampal subregions and corresponding functionally abnormal regions was also conducted using probabilistic tractography. Antidepressant effects and cognitive impairments were measured by the Hamilton Depressive Rating Scale (HDRS) and the Category Verbal Fluency Test (CVFT), respectively. Their relationships with hippocampal-subregions alterations were examined.ResultsAfter ECT, patients showed increased RSFC in the hippocampal emotional subregion (HIPe) with the left middle occipital gyrus (LMOG) and right medial temporal gyrus (RMTG). Decreased HDRS was associated with increased HIPe-RMTG RSFC (r = −0.316, p = 0.035) significantly and increased HIPe-LMOG RSFC at trend level (r = −0.283, p = 0.060). In contrast, the hippocampal cognitive subregion showed decreased RSFC with the bilateral angular gyrus, and was correlated with decreased CVFT (r = 0.418, p = 0.015 for left; r = 0.356, p = 0.042 for right). No significant changes were found in structural connectivity.ConclusionThe hippocampal-subregions functional alterations may be specially associated with the antidepressant and cognitive effects of ECT.

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Morriss, Richard, Lucy Webster, Mohamed Abdelghani, Dorothee P. Auer, Shaun Barber, Peter Bates, Andrew Blamire et al. "Connectivity guided theta burst transcranial magnetic stimulation versus repetitive transcranial magnetic stimulation for treatment-resistant moderate to severe depression: study protocol for a randomised double-blind controlled trial (BRIGhTMIND)". BMJ Open 10, n.º 7 (julho de 2020): e038430. http://dx.doi.org/10.1136/bmjopen-2020-038430.

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IntroductionThe BRIGhTMIND study aims to determine the clinical effectiveness, cost-effectiveness and mechanism of action of connectivity guided intermittent theta burst stimulation (cgiTBS) versus standard repetitive transcranial magnetic stimulation (rTMS) in adults with moderate to severe treatment resistant depression.Methods and analysisThe study is a randomised double-blind controlled trial with 1:1 allocation to either 20 sessions of (1) cgiTBS or (2) neuronavigated rTMS not using connectivity guidance. A total of 368 eligible participants with a diagnosis of current unipolar major depressive disorder that is both treatment resistant (defined as scoring 2 or more on the Massachusetts General Hospital Staging Score) and moderate to severe (scoring >16 on the 17-item Hamilton Depression Rating Scale (HDRS-17)), will be recruited from primary and secondary care settings at four treatment centres in the UK. The primary outcome is depression response at 16 weeks (50% or greater reduction in HDRS-17 score from baseline). Secondary outcomes include assessments of self-rated depression, anxiety, psychosocial functioning, cognition and quality of life at 8, 16 and 26 weeks postrandomisation. Cost-effectiveness, patient acceptability, safety, mechanism of action and predictors of response will also be examined.Ethics and disseminationEthical approval was granted by East Midlands Leicester Central Research Ethics Committee (ref: 18/EM/0232) on 30 August 2018. The results of the study will be published in relevant peer-reviewed journals, and then through professional and public conferences and media. Further publications will explore patient experience, moderators and mediators of outcome and mechanism of action.Trial registration numberISRCTN19674644

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Kaneko, Tomoki, Toshinori Nakamura, Akiko Ryokawa, Shinsuke Washizuka, Yoshihiro Kitoh e Yasunari Fujinaga. "Connective differences between patients with depression with and without ASD: A case-control study". PLOS ONE 18, n.º 8 (15 de agosto de 2023): e0289735. http://dx.doi.org/10.1371/journal.pone.0289735.

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Background Researchers find it difficult to distinguish between depression with ASD (Depress-wASD) and without ASD (Depression) in adult patients. We aimed to clarify the differences in brain connectivity between patients with depression with ASD and without ASD. Methods From April 2017 to February 2019, 22 patients with suspected depression were admitted to the hospital for diagnosis or follow-up and met the inclusion criteria. The diagnosis was determined according to the Diagnostic and Statistical Manual of Mental Disorders-5 by skilled psychiatrists. The Hamilton Depression Rating Scale (HAM-D), Young Mania Raging Scale (YMRS), Mini-International Neuropsychiatric Interview, Parent-interview ASD Rating Scale-Text Revision (PARS-TR), and Autism-Spectrum Quotient-Japanese version (AQ-J) were used to assess the patients’ background and help with diagnosis. Resting-state functional magnetic resonance imaging (rs-fMRI) was performed using the 3-T-MRI system. rs-fMRI was processed using the CONN functional connectivity toolbox. Voxel-based morphometry was performed using structural images. Results No significant difference was observed between the Depress-wASD and Depression groups using the HAM-D, YMRS, AQ-J, Intelligence Quotient (IQ), and verbal IQ results. rs-fMRI for the Depress-wASD group indicated a positive connection between the salience network (SN) and right supramarginal gyrus (SMG) and a negative connection between the SN and hippocampus and para-hippocampus than that for the Depression group. No significant structural differences were observed between the groups. Conclusions We identified differences in the SN involving the SMG and hippocampal regions between the Depress-wASD and Depression groups.

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Zhang, Peiyao, Qin Xu, Jianping Dai, Jun Wang, Ning Zhang e Yuejia Luo. "Dysfunction of Affective Network in Post Ischemic Stroke Depression: A Resting-State Functional Magnetic Resonance Imaging Study". BioMed Research International 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/846830.

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Objective. Previous studies have demonstrated that stroke characteristics and social and psychological factors jointly contribute to the development of poststroke depression (PSD). The purpose of this study was to identify altered functional connectivity (FC) of the affective network (AN) in patients with PSD and to explore the correlation between FC and the severity of PSD.Materials and Methods. 26 PSD patients, 24 stroke patients without depression, and 24 age-matched normal controls underwent the resting-state functional MRI (fMRI) scanning. The bilateral anterior cingulated cortices (ACCs) were selected as regions of interest (ROIs). FC was calculated and compared among the three groups. The association between FC and Hamilton Depression Rate Scale (HDRS) scores of PSD group was investigated.Results. The FC of the AN was disrupted in PSD patients compared to stroke patients without depression and normal controls. Moreover, the left orbital part of inferior frontal gyrus which indicated altered FC was significantly correlated with HDRS scores in PSD patients.Conclusions. Dysfunction of the affective network may be one of the reasons of the development of PSD.

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Xue, Shao-Wei, Changxiao Kuai, Yang Xiao, Lei Zhao e Zhihui Lan. "Abnormal Dynamic Functional Connectivity of the Left Rostral Hippocampus in Predicting Antidepressant Efficacy in Major Depressive Disorder". Psychiatry Investigation 19, n.º 7 (25 de julho de 2022): 562–69. http://dx.doi.org/10.30773/pi.2021.0386.

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Objective Some pharmacological treatments are ineffective in parts of patients with major depressive disorder (MDD), hence this needs prediction of effective treatment responses. The study aims to examine the relationship between dynamic functional connectivity (dFC) of the hippocampal subregion and antidepressant improvement of MDD patients and to estimate the capability of dFC to predict antidepressant efficacy.Methods The data were from 70 MDD patients and 43 healthy controls (HC); the dFC of hippocampal subregions was estimated by sliding-window approach based on resting-state functional magnetic resonance imaging (R-fMRI). After 3 months treatment, 36 patients underwent second R-fMRI scan and were then divided into the response group and non-response group according to clinical responses.Results The result manifested that MDD patients exhibited lower mean dFC of the left rostral hippocampus (rHipp.l) compared with HC. After 3 months therapy, the response group showed lower dFC of rHipp.l compared with the non-response group. The dFC of rHipp.l was also negatively correlated with the reduction rate of Hamilton Depression Rating Scale.Conclusion These findings highlighted the importance of rHipp in MDD from the dFC perspective. Detection and estimation of these changes might demonstrate helpful for comprehending the pathophysiological mechanism and for assessment of treatment reaction of MDD.

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Hou, Z., X. Song, W. Jiang, Y. Yue, Y. Yin, Y. Zhang, Y. Liu e Y. Yuan. "Association analysis of imbalanced interhemispheric functional coordination and early therapeutic efficacy in major depressive disorder: Evidence from resting state fMRI". European Psychiatry 33, S1 (março de 2016): S87—S88. http://dx.doi.org/10.1016/j.eurpsy.2016.01.048.

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IntroductionEmerging evidences indicate that the alteration of interhemispheric functional coordination may be involved in the pathogenesis of major depressive disorder (MDD). In present study, we aim to explore the potential marker by using the voxel-mirrored homotopic connectivity (VMHC) approach, which may be contributing to predict the clinical prognosis in MDD.MethodsEighty-two MDD patients and 50 normal control (NC) subjects participated in this study. We divided the MDD group into unremitted and remitted group according to the reduction rate of Hamilton Rating Scale for Depression (HAMD) within 2 weeks.ResultsThe study detected significantly decreased VMHC in bilateral precuneus (pCu), inferior temporal gyrus (ITG) and increased VMHC in middle frontal gyrus (MFG) and caudate nucleus when compared remitted depression (RD) group to unremitted depression (URD) group. Meanwhile, when compared with NC group, the URD group presented reduced VMHC in bilateral cerebellum anterior lobe, thalamus and postcentral gyrus. Furthermore, the VHMC in media frontal gyrus, postcentral gyrus and precentral gyrus were significantly decreased in RD group. Correlation analysis suggested that reduced VMHC in bilateral pCu was negatively correlated with the baseline HAMD score of URD (r = −0.325, P = 0.041). Receiver operating characteristic (ROC) curve indicated that three regional VMHC changes could identify depressed patient with poorer treatment response: ITG [area under curve (AUC) = 0.699, P = 0.002, 95% CI = 0.586–0.812], MFG (AUC = 0.692, P = 0.003, 95% CI = 0.580–0.805), pCu (AUC = 0.714, P = 0.001, 95% CI = 0.603–0.825).ConclusionThe current study combined with previous evidence indicates that the subdued intrinsic interhemispheric functional connectivity might represents a novel neural trait involved in the pathophysiology of MDD.Disclosure of interestThe authors have not supplied their declaration of competing interest.

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Zhang, Shuai, Jia-Kai He, Gang-Liang Zhong, Yu Wang, Ya-Nan Zhao, Lei Wang, Shao-Yuan Li et al. "Prolonged Longitudinal Transcutaneous Auricular Vagus Nerve Stimulation Effect on Striatal Functional Connectivity in Patients with Major Depressive Disorder". Brain Sciences 12, n.º 12 (17 de dezembro de 2022): 1730. http://dx.doi.org/10.3390/brainsci12121730.

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Background: Transcutaneous auricular vagus nerve stimulation (taVNS) is effective for treating major depressive disorder (MDD). We aimed to explore the modulating effect of prolonged longitudinal taVNS on the striatal subregions’ functional connectivity (FC) in MDD patients. Methods: Sixteen MDD patients were enrolled and treated with taVNS for 8 weeks. Sixteen healthy control subjects (HCs) were recruited without intervention. The resting-state FC (rsFC) based on striatal subregion seed points and the Hamilton Depression Scale (HAMD) were evaluated in the MDD patients and HCs at baseline and after 8 weeks. A two-way ANCOVA test was performed on each rsFC metric to obtain the (group-by-time) interactions. Results: The rsFC values between the left ventral caudate (vCa) and right ventral prefrontal cortex (vPFC), and between the right nucleus accumbens (NAc) and right dorsal medial prefrontal cortex (dmPFC) and ventrolateral prefrontal cortex (vlPFC) are lower in the MDD patients compared to the HCs at baseline, and increase following taVNS; the rsFC values between the left vCa and right, superior occipital gyrus (SOG), and between the left dorsal caudate (dCa) and right cuneus are higher in MDD patients and decrease following taVNS. Conclusions: Prolonged longitudinal taVNS can modulate the striatum rsFC with the prefrontal cortex, occipital cortex, temporal cortex, and intra-striatum, and these changes partly underlie any symptomatic improvements. The results indicate that prolonged longitudinal taVNS may produce beneficial treatment effects by modulating the cortical striatum circuitry in patients with MDD.

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Wang, Yirong, Shushan Zhang, Haodi Yang, Xin Zhang, Shijia He, Jian Wang e Jian Li. "Altered cerebellum functional network on newly diagnosed drug-naïve Parkinson’s disease patients with anxiety". Translational Neuroscience 12, n.º 1 (1 de janeiro de 2021): 415–24. http://dx.doi.org/10.1515/tnsci-2020-0192.

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Abstract Introduction Damage to the cerebellar functional network may underlie anxiety symptoms in patients with Parkinson’s disease (PD). Herein we investigated the regional homogeneity (ReHo) and functional connectivity (FC) patterns of cerebellar and clinical correlates in PD patients with anxiety and explored their clinical significance. Methods We enrolled 50 newly diagnosed drug-naïve PD patients and 30 normal controls (NCs). Twenty-six PD patients with anxiety symptoms (PD-A) and 24 PD patients without anxiety symptoms (PD-NA) were sorted into groups based on the Hamilton Anxiety Scale (HAMA). All included participants underwent rest-state functional magnetic resonance imaging (rs-fMRI) scanning. Cerebellar FC based on the seed-based method was used to investigate regional and whole brain function in PD-A, PD-NA, and NCs, and the relationship between the abnormal brain function and anxiety symptoms in PD patients was also detected. Results Compared with the PD-NA group and the NCs, the ReHo value of the PD-A group was significantly decreased in the left medial frontal gyrus and increased in the left cerebellum. Further, left-cerebellum-based FC patterns were used to detect the decreased FC in the right cerebellum, while FC was increased in the right caudate nucleus, and the right anterior cingulate cortex (ACC) in the PD-A group was compared with that in the PD-NA group. Further, the altered FC between the left cerebellum and the right cerebellum was significantly associated with anxiety symptoms in the PD-A group. Conclusion The present study found abnormal regional cerebellum function as well as disruptions in the connectivity network within the cerebellum, caudate, and ACC in patients with PD-A. In addition, the FC between the left cerebellum and the right cerebellum was associated with anxiety symptoms in patients with PD. The present study indicated that cerebellar functional damage may be associated with anxiety symptoms in PD patients.

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Alcala, Y., D. Brito, O. Castro e L. Marin. "HAMILTON-CONNECTIVITY IN BALANCED BIPARTITE GRAPHS". International Journal of Pure and Apllied Mathematics 102, n.º 4 (12 de julho de 2015). http://dx.doi.org/10.12732/ijpam.v102i4.2.

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Liu, Wenyu, Xinyu Hu, Dongmei An, Dong Zhou e Qiyong Gong. "Resting-state functional connectivity alterations in periventricular nodular heterotopia related epilepsy". Scientific Reports 9, n.º 1 (dezembro de 2019). http://dx.doi.org/10.1038/s41598-019-55002-3.

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AbstractPeriventricular nodular heterotopia (PNH) is a neural migration disorder which often presents clinically with seizures. However, the underlying functional neural basis of PNH is still unclear. We aimed to explore the underlying pathological mechanism of PNH by combining both whole brain functional connectivity (FC) and seed-based FC analyses. We utilized resting-state fMRI to measure functional connectivity strength (FCS) in 38 patients with PNH-related epilepsy and 38 control subjects. The regions with FCS alterations were selected as seeds in the following FC analyses. Pearson correlation analyses were performed to explore associations between these functional neural correlates and clinical features. In comparison with controls, PNH patients showed lower FCS in bilateral insula (P < 0.05, family wise error (FWE) correction), higher FC in the default mode network and lower FC in the fronto-limbic-cerebellar circuits (P < 0.05, FWE correction). Pearson correlation analyses revealed that FCS in bilateral insula was negatively correlated with the epilepsy duration (P < 0.05); medial prefronto-insular connectivity was negatively correlated with Hamilton Anxiety Scale (P < 0.05) and cerebellar-insular connectivity was also negatively correlated with Hamilton Depression Scale (P < 0.05). Using the resting-state FCS analytical approach, we identified significant insular hypoactivation in PNH patients, which suggests that the insula might represent the cortical hub of the whole-brain networks in this condition. Additionally, disruption of resting state FC in large-scale neural networks pointed to a connectivity-based neuropathological process in PNH.

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Rybarczyk, Katarzyna. "Sharp Threshold Functions for Random Intersection Graphs via a Coupling Method". Electronic Journal of Combinatorics 18, n.º 1 (14 de fevereiro de 2011). http://dx.doi.org/10.37236/523.

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We present a new method which enables us to find threshold functions for many properties in random intersection graphs. This method is used to establish sharp threshold functions in random intersection graphs for $k$–connectivity, perfect matching containment and Hamilton cycle containment.

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Zhou, Qiannan, Hajo Broersma, Ligong Wang e Yong Lu. "Sufficient Spectral Radius Conditions for Hamilton-Connectivity of k-Connected Graphs". Graphs and Combinatorics, 16 de julho de 2021. http://dx.doi.org/10.1007/s00373-021-02369-8.

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AbstractWe present two new sufficient conditions in terms of the spectral radius $$\rho (G)$$ ρ ( G ) guaranteeing that a k-connected graph G is Hamilton-connected, unless G belongs to a collection of exceptional graphs. We use the Bondy–Chvátal closure to characterize these exceptional graphs.

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Zhong, Yubin, Sakander Hayat e Asad Khan. "Hamilton-connectivity of line graphs with application to their detour index". Journal of Applied Mathematics and Computing, 2 de junho de 2021. http://dx.doi.org/10.1007/s12190-021-01565-2.

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Morriss, Richard, Paul M. Briley, Lucy Webster, Mohamed Abdelghani, Shaun Barber, Peter Bates, Cassandra Brookes et al. "Connectivity-guided intermittent theta burst versus repetitive transcranial magnetic stimulation for treatment-resistant depression: a randomized controlled trial". Nature Medicine, 16 de janeiro de 2024. http://dx.doi.org/10.1038/s41591-023-02764-z.

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AbstractDisruption in reciprocal connectivity between the right anterior insula and the left dorsolateral prefrontal cortex is associated with depression and may be a target for neuromodulation. In a five-center, parallel, double-blind, randomized controlled trial we personalized resting-state functional magnetic resonance imaging neuronavigated connectivity-guided intermittent theta burst stimulation (cgiTBS) at a site based on effective connectivity from the right anterior insula to the left dorsolateral prefrontal cortex. We tested its efficacy in reducing the primary outcome depression symptoms measured by the GRID Hamilton Depression Rating Scale 17-item over 8, 16 and 26 weeks, compared with structural magnetic resonance imaging (MRI) neuronavigated repetitive transcranial magnetic stimulation (rTMS) delivered at the standard stimulation site (F3) in patients with ‘treatment-resistant depression’. Participants were randomly assigned to 20 sessions over 4–6 weeks of either cgiTBS (n = 128) or rTMS (n = 127) with resting-state functional MRI at baseline and 16 weeks. Persistent decreases in depressive symptoms were seen over 26 weeks, with no differences between arms on the primary outcome GRID Hamilton Depression Rating Scale 17-item score (intention-to-treat adjusted mean, −0.31, 95% confidence interval (CI) −1.87, 1.24, P = 0.689). Two serious adverse events were possibly related to TMS (mania and psychosis). MRI-neuronavigated cgiTBS and rTMS were equally effective in patients with treatment-resistant depression over 26 weeks (trial registration no. ISRCTN19674644).

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Li, Hui, Wei Yan, Qianwen Wang, Lin Liu, Xiao Lin, Ximei Zhu, Sizhen Su et al. "Mindfulness-Based Cognitive Therapy Regulates Brain Connectivity in Patients With Late-Life Depression". Frontiers in Psychiatry 13 (14 de fevereiro de 2022). http://dx.doi.org/10.3389/fpsyt.2022.841461.

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Late-life depression (LLD) is an important public health problem among the aging population. Recent studies found that mindfulness-based cognitive therapy (MBCT) can effectively alleviate depressive symptoms in major depressive disorder. The present study explored the clinical effect and potential neuroimaging mechanism of MBCT in the treatment of LLD. We enrolled 60 participants with LLD in an 8-week, randomized, controlled trial (ChiCTR1800017725). Patients were randomized to the treatment-as-usual (TAU) group or a MBCT+TAU group. The Hamilton Depression Scale (HAMD) and Hamilton Anxiety Scale (HAMA) were used to evaluate symptoms. Magnetic resonance imaging (MRI) was used to measure changes in resting-state functional connectivity and structural connectivity. We also measured the relationship between changes in brain connectivity and improvements in clinical symptoms. HAMD total scores in the MBCT+TAU group were significantly lower than in the TAU group after 8 weeks of treatment (p < 0.001) and at the end of the 3-month follow-up (p < 0.001). The increase in functional connections between the amygdala and middle frontal gyrus (MFG) correlated with decreases in HAMA and HAMD scores in the MBCT+TAU group. Diffusion tensor imaging analyses showed that fractional anisotropy of the MFG-amygdala significantly increased in the MBCT+TAU group after 8-week treatment compared with the TAU group. Our study suggested that MBCT improves depression and anxiety symptoms that are associated with LLD. MBCT strengthened functional and structural connections between the amygdala and MFG, and this increase in communication correlated with improvements in clinical symptoms.Randomized Controlled Trial; Follow-Up Study; fMRI; Brain Connectivity

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Gong, Haiyan, Hui Sun, Yeyang Ma, Yaling Tan, Minglong Cui, Ming Luo e Yuhui Chen. "Prefrontal brain function in patients with chronic insomnia disorder: A pilot functional near-infrared spectroscopy study". Frontiers in Neurology 13 (15 de dezembro de 2022). http://dx.doi.org/10.3389/fneur.2022.985988.

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PurposeInsomnia is one of the most common diseases in elderly patients, which seriously affect the quality of life and psychological state of patients. The purpose of this study was to investigate the changes in the functional network pattern of the prefrontal cortex in patients with chronic insomnia disorder (CID) after taking drugs, using non-invasive and low-cost functional neuroimaging with multi-channel near-infrared spectroscopy (fNIRS).MethodsAll subjects were assessed using the Pittsburgh Sleep Quality Index (PSQI), Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), and fNIRS. The fNIRS assessment consists of two parts: the verbal fluency test (VFT) task state and the resting state, which assessed the differences in prefrontal activation and functional connectivity, respectively.ResultsA total of 30 patients with chronic insomnia disorder (CID) and 15 healthy peers completed the study. During the VFT task, a significantly lower PFC activation was observed in patients with insomnia compared to the control group (P < 0.05). However, the PFC activation in patients taking medication was higher than in patients who did not receive medication. Functional connectivity analysis showed a weaker mean PFC channel connectivity strength in patients with CID who did not receive drug treatment. Drug treatment resulted in enhanced functional connectivity of the prefrontal lobe, especially the DLPFC and frontal poles.ConclusionA weak prefrontal cortex response was detected in patients with CID when performing the VFT task, which could be enhanced by taking hypnotics. The weakened right prefrontal lobe network may play a role in the development of CID. fNIRS may serve as a potential tool to assess sleep status and guide drug therapy.

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Chen, Wen, Hao Hu, Qian Wu, Lu Chen, Jiang Zhou, Huan-Huan Chen, Xiao-Quan Xu e Fei-Yun Wu. "Altered Static and Dynamic Interhemispheric Resting-State Functional Connectivity in Patients With Thyroid-Associated Ophthalmopathy". Frontiers in Neuroscience 15 (6 de dezembro de 2021). http://dx.doi.org/10.3389/fnins.2021.799916.

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Purpose: Thyroid-associated ophthalmopathy (TAO) is a debilitating and sight-threatening autoimmune disease that severely impairs patients’ quality of life. Besides the most common ophthalmic manifestations, the emotional and psychiatric disturbances are also usually observed in clinical settings. This study was to investigate the interhemispheric functional connectivity alterations in TAO patients using resting-state functional magnetic resonance imaging (rs-fMRI).Methods: Twenty-eight TAO patients and 22 healthy controls (HCs) underwent rs-fMRI scans. Static and dynamic voxel-mirrored homotopic connectivity (VMHC) values were calculated and compared between the two groups. A linear support vector machine (SVM) classifier was used to examine the performance of static and dynamic VMHC differences in distinguishing TAOs from HCs.Results: Compared with HCs, TAOs showed decreased static VMHC in lingual gyrus (LG)/calcarine (CAL), middle occipital gyrus, postcentral gyrus, superior parietal lobule, inferior parietal lobule, and precuneus. Meanwhile, TAOs demonstrated increased dynamic VMHC in orbitofrontal cortex (OFC). In TAOs, static VMHC in LG/CAL was positively correlated with visual acuity (r = 0.412, P = 0.036), whilst dynamic VMHC in OFC was positively correlated with Hamilton Anxiety Rating Scale (HARS) score (r = 0.397, P = 0.044) and Hamilton Depression Rating Scale (HDRS) score (r = 0.401, P = 0.042). The SVM model showed good performance in distinguishing TAOs from HCs (area under the curve, 0.971; average accuracy, 94%).Conclusion: TAO patients had altered static and dynamic VMHC in the occipital, parietal, and orbitofrontal areas, which could serve as neuroimaging prediction markers of TAO.

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Chiba, Shuya, Michitaka Furuya, Kenta Ozeki, Masao Tsugaki e Tomoki Yamashita. "A Degree Sum Condition on the Order, the Connectivity and the Independence Number for Hamiltonicity". Electronic Journal of Combinatorics 26, n.º 4 (20 de dezembro de 2019). http://dx.doi.org/10.37236/5480.

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In [Graphs Combin. 24 (2008) 469–483], the third author and the fifth author conjectured that if $G$ is a $k$-connected graph such that $\sigma_{k+1}(G) \ge |V(G)|+\kappa(G)+(k-2)(\alpha(G)-1)$, then $G$ contains a Hamilton cycle, where $\sigma_{k+1}(G)$, $\kappa(G)$ and $\alpha(G)$ are the minimum degree sum of $k+1$ independent vertices, the connectivity and the independence number of $G$, respectively. In this paper, we settle this conjecture. The degree sum condition is best possible.

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Mi, Wei-Feng, Serik Tabarak, Li Wang, Su-Zhen Zhang, Xiao Lin, Lan-Ting Du, Zhen Liu et al. "Effects of agomelatine and mirtazapine on sleep disturbances in major depressive disorder: evidence from polysomnographic and resting-state functional connectivity analyses". Sleep 43, n.º 11 (14 de maio de 2020). http://dx.doi.org/10.1093/sleep/zsaa092.

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Abstract To investigate effects of agomelatine and mirtazapine on sleep disturbances in patients with major depressive disorder. A total of 30 depressed patients with sleep disturbances, 27 of which completed the study, took agomelatine or mirtazapine for 8 weeks. Subjective scales were administered, and polysomnography was performed at baseline and at the end of week 1 and 8. Functional magnetic resonance imaging was performed at baseline and at the end of week 8. Compared with baseline, scores on the Hamilton Depression Scale, Hamilton Anxiety Scale, Pittsburgh Sleep Quality Index, Sleep Dysfunction Rating Scale, and Insomnia Severity Index after 8 weeks of treatment significantly decreased in both groups, with no significant differences between groups, accompanied by significant increases in total sleep time, sleep efficiency, and rapid eye movement (REM) sleep and significant decrease in wake after sleep onset. Mirtazapine treatment increased N3 sleep at week 1 compared with agomelatine treatment, but this difference disappeared at week 8. The increases in the percentage and duration of N3 sleep were positively correlated with increases in connectivity between right dorsal lateral prefrontal cortex (dlPFC) and right precuneus and between left posterior cingulate cortex and right precuneus in both groups, respectively. Functional connectivity (FC) between right dlPFC and left precuneus in mirtazapine group was higher compared with agomelatine group after 8 weeks of treatment. These findings indicated that both agomelatine and mirtazapine improved sleep in depressed patients, and the effect of mirtazapine was greater than agomelatine with regard to rapidly increasing N3 sleep and gradually improving FC in the brain.

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Lobo, Bento J., Andy Novobilski e Soumen Ghosh. "The Economic Impact Of Broadband: Estimates From A Regional Input-Output Model". Journal of Applied Business Research (JABR) 24, n.º 2 (14 de janeiro de 2011). http://dx.doi.org/10.19030/jabr.v24i2.1357.

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Like good roads, schools, and hospitals, cutting-edge broadband infrastructure is crucial to economic development and to the quality of life of local communities. Second-generation broadband (SGB), capable of supporting video, voice and data services simultaneously over a fiber-optic infrastructure, can provide users not merely faster internet connectivity, but a whole array of applications and communication services. This study provides an approach to quantifying the economic effects of first and second generation broadband availability in Hamilton County (TN) using an IMPLAN model. We find that household broadband expenditures over the period 2001-2005 supported 548 jobs and contributed $109.8 million in income and taxes to Hamilton County. Further, we estimate that while a new fiber-to-the-home project would cost $195.5 million over ten years, the economic impact of such a project would result in income and taxes exceeding $352 million while creating over 2,600 new jobs. We conclude that Hamilton County would benefit from the adoption of this technology.

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Li, Chunyan, Xiaomin Pang, Ke Shi, Qijia Long, Jinping Liu e Jinou Zheng. "The Insula Is a Hub for Functional Brain Network in Patients With Anti-N-Methyl-D-Aspartate Receptor Encephalitis". Frontiers in Neuroscience 15 (15 de março de 2021). http://dx.doi.org/10.3389/fnins.2021.642390.

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BackgroundIn recent years, imaging technologies have been rapidly evolving, with an emphasis on the characterization of brain structure changes and functional imaging in patients with autoimmune encephalitis. However, the neural basis of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis and its linked cognitive decline is unclear. Our research aimed to assess changes in the functional brain network in patients with anti-NMDAR encephalitis and whether these changes lead to cognitive impairment.MethodsTwenty-one anti-NMDAR encephalitis patients and 22 age-, gender-, and education status-matched healthy controls were assessed using resting functional magnetic resonance imaging (fMRI) scanning and neuropsychological tests, including the Hamilton Depression Scale (HAMD24), the Montreal Cognitive Assessment (MoCA), and the Hamilton Anxiety Scale (HAMA). A functional brain network was constructed using fMRI, and the topology of the network parameters was analyzed using graph theory. Next, we extracted the aberrant topological parameters of the functional network as seeds and compared causal connectivity with the whole brain. Lastly, we explored the correlation of aberrant topological structures with deficits in cognitive performance.ResultsRelative to healthy controls, anti-NMDAR encephalitis patients exhibited decreased MoCA scores and increased HAMA and HAMD24 scores (p < 0.05). The nodal clustering coefficient and nodal local efficiency of the left insula (Insula_L) were significantly decreased in anti-NMDAR encephalitis patients (p < 0.05 following Bonferroni correction). Moreover, anti-NMDAR encephalitis patients showed a weakened causal connectivity from the left insula to the left inferior parietal lobe (Parietal_Inf_L) compared to healthy controls. Conversely, the left superior parietal lobe (Parietal_sup_L) exhibited an enhanced causal connectivity to the left insula in anti-NMDAR encephalitis patients compared to controls. Unexpectedly, these alterations were not correlated with any neuropsychological test scores.ConclusionThis research describes topological abnormalities in the functional brain network in anti-NMDAR encephalitis. These results will be conducive to understand the structure and function of the brain network of patients with anti-NMDAR encephalitis and further explore the neuropathophysiological mechanisms.

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Mayers, Rebecca, Nicole Rallis, Brian Doucet e Caleb Babin. "In light of transit: Documenting the scales of urban change along the LRT line in Hamilton, Ontario". Canadian Geographies / Géographies canadiennes, 13 de outubro de 2023. http://dx.doi.org/10.1111/cag.12890.

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AbstractLarge‐scale transit projects, such as light rail, are transformational for cities due to their ability to attract investment, curb sprawl, and intensify urban areas. In part because of enhancements to the public realm and improved connectivity, areas along new transit lines witness significant growth and investment, making them less affordable for residents already there. However, very little research has examined experiences of transit‐induced gentrification, particularly at the early stages of a new transit project. The purpose of this article is to document these experiences from the perspective of those living along the planned LRT corridor in Hamilton, Ontario. Importantly, our research was conducted before construction started. Through in‐depth interviews with residents living within 800 m of the planned LRT route, we found disparate experiences of change and ongoing housing affordability concerns on an individual, neighbourhood, and city scale. Many Hamilton residents express a need for more community engagement and transparency in the decision‐making process. We detail these experiences and offer policy recommendations to inhibit further housing insecurity and displacement in light of the LRT development.

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Krivelevich, Michael, e Tibor Szabó. "Biased Positional Games and Small Hypergraphs with Large Covers". Electronic Journal of Combinatorics 15, n.º 1 (5 de maio de 2008). http://dx.doi.org/10.37236/794.

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We prove that in the biased $(1:b)$ Hamiltonicity and $k$-connectivity Maker-Breaker games ($k>0$ is a constant), played on the edges of the complete graph $K_n$, Maker has a winning strategy for $b\le(\log 2-o(1))n/\log n$. Also, in the biased $(1:b)$ Avoider-Enforcer game played on $E(K_n)$, Enforcer can force Avoider to create a Hamilton cycle when $b\le (1-o(1))n/\log n$. These results are proved using a new approach, relying on the existence of hypergraphs with few edges and large covering number.

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Zhao, Tingting, Lixia Pei, Houxu Ning, Jing Guo, Yafang Song, Junling Zhou, Lu Chen, Jianhua Sun e Zhongping Mi. "Networks Are Associated With Acupuncture Treatment in Patients With Diarrhea-Predominant Irritable Bowel Syndrome: A Resting-State Imaging Study". Frontiers in Human Neuroscience 15 (14 de outubro de 2021). http://dx.doi.org/10.3389/fnhum.2021.736512.

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Background: Irritable Bowel Syndrome (IBS), as a functional gastrointestinal disorder, is characterized by abdominal pain and distension. Recent studies have shown that acupuncture treatment improves symptoms of diarrhea-predominant irritable bowel syndrome (IBS-D) by altering networks in certain brain regions. However, few studies have used resting-state functional magnetic resonance imaging (fMRI) to compare altered resting-state inter-network functional connectivity in IBS-D patients before and after acupuncture treatment.Objective: To analyze altered resting-state inter-network functional connectivity in IBS-D patients before and after acupuncture treatment.Methods: A total of 74 patients with IBS-D and 31 healthy controls (HCs) were recruited for this study. fMRI examination was performed in patients with IBS-D before and after acupuncture treatment, but only at baseline in HCs. Data on the left frontoparietal network (LFPN), default mode network (DMN), salience network (SN), ventral attention network (VAN), auditory network (AN), visual network (VN), sensorimotor network (SMN), dorsal attention network (DAN), and right frontoparietal network (RFPN) were subjected to independent component analysis (ICA). The functional connectivity values of inter-network were explored.Results: Acupuncture decreased irritable bowel syndrome symptom severity score (IBS-SSS) and Hamilton Anxiety Scale (HAMA). It also ameliorated symptoms related to IBS-D. Notably, functional connectivity between AN and VAN, SMN and DMN, RFPN and VAN in IBS-D patients after acupuncture treatment was different from that in HCs. Furthermore, there were differences in functional connectivity between DMN and DAN, DAN and LFPN, DMN and VAN before and after acupuncture treatment. The inter-network changes in DMN-VAN were positively correlated with changes in HAMA, life influence degree, and IBS-SSS in IBS-D.Conclusion: Altered inter-network functional connectivity is involved in several important hubs in large-scale networks. These networks are altered by acupuncture stimulation in patients with IBS-D.

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Pantazatos, Spiro P., Ashley Yttredahl, Harry Rubin-Falcone, Ronit Kishon, Maria A. Oquendo, J. John Mann e Jeffrey M. Miller. "Depression-related anterior cingulate prefrontal resting state connectivity normalizes following cognitive behavioral therapy". European Psychiatry 63, n.º 1 (2020). http://dx.doi.org/10.1192/j.eurpsy.2020.34.

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Abstract Background. Aberrant activity of the subcallosal cingulate (SCC) is a common theme across pharmacologic treatment efficacy prediction studies. The functioning of the SCC in psychotherapeutic interventions is relatively understudied, as are functional differences among SCC subdivisions. We conducted functional connectivity analyses (rsFC) on resting-state functional magnetic resonance imaging (fMRI) data, collected before and after a course of cognitive behavioral therapy (CBT) in patients with major depressive disorder (MDD), using seeds from three SCC subdivisions. Methods. Resting-state data were collected from unmedicated patients with current MDD (Hamilton Depression Rating Scale-17 > 16) before and after 14-sessions of CBT monotherapy. Treatment outcome was assessed using the Beck Depression Inventory (BDI). Rostral anterior cingulate (rACC), anterior subcallosal cingulate (aSCC), and Brodmann’s area 25 (BA25) masks were used as seeds in connectivity analyses that assessed baseline rsFC and symptom severity, changes in connectivity related to symptom improvement after CBT, and prediction of treatment outcomes using whole-brain baseline connectivity. Results. Pretreatment BDI negatively correlated with pretreatment rACC ~ dorsolateral prefrontal cortex and aSCC ~ lateral prefrontal cortex rsFC. In a region-of-interest longitudinal analysis, rsFC between these regions increased post-treatment (p < 0.05FDR). In whole-brain analyses, BA25 ~ paracentral lobule and rACC ~ paracentral lobule connectivities decreased post-treatment. Whole-brain baseline rsFC with SCC did not predict clinical improvement. Conclusions. rsFC features of rACC and aSCC, but not BA25, correlated inversely with baseline depression severity, and increased following CBT. Subdivisions of SCC involved in top-down emotion regulation may be more involved in cognitive interventions, while BA25 may be more informative for interventions targeting bottom-up processing. Results emphasize the importance of subdividing the SCC in connectivity analyses.

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