3,695 research outputs found

    Presurgical thalamic hubness predicts surgical outcome in temporal lobe epilepsy.

    Get PDF
    OBJECTIVE: To characterize the presurgical brain functional architecture presented in patients with temporal lobe epilepsy (TLE) using graph theoretical measures of resting-state fMRI data and to test its association with surgical outcome. METHODS: Fifty-six unilateral patients with TLE, who subsequently underwent anterior temporal lobectomy and were classified as obtaining a seizure-free (Engel class I, n = 35) vs not seizure-free (Engel classes II-IV, n = 21) outcome at 1 year after surgery, and 28 matched healthy controls were enrolled. On the basis of their presurgical resting-state functional connectivity, network properties, including nodal hubness (importance of a node to the network; degree, betweenness, and eigenvector centralities) and integration (global efficiency), were estimated and compared across our experimental groups. Cross-validations with support vector machine (SVM) were used to examine whether selective nodal hubness exceeded standard clinical characteristics in outcome prediction. RESULTS: Compared to the seizure-free patients and healthy controls, the not seizure-free patients displayed a specific increase in nodal hubness (degree and eigenvector centralities) involving both the ipsilateral and contralateral thalami, contributed by an increase in the number of connections to regions distributed mostly in the contralateral hemisphere. Simulating removal of thalamus reduced network integration more dramatically in not seizure-free patients. Lastly, SVM models built on these thalamic hubness measures produced 76% prediction accuracy, while models built with standard clinical variables yielded only 58% accuracy (both were cross-validated). CONCLUSIONS: A thalamic network associated with seizure recurrence may already be established presurgically. Thalamic hubness can serve as a potential biomarker of surgical outcome, outperforming the clinical characteristics commonly used in epilepsy surgery centers

    A Study of Dew Water Yields on Galvanized Iron Roof in Kothara (North-West India)

    Get PDF
    In order to determine what amount of dew water can be collected without much investment during the dry season (October –May) in north - west India, a study was performed on plain, un-insulated, corrugated galvanized iron roofs that are common in this rural region. Between October 1, 2004 and May 31, 2005, the cumulative dew yield on a 18 m2 double - sloped (30�) test roof was 113.5 L. The west side gave 35 % higher water yield than the east side. The use of thermal insulation and more IR radiative materials would have increased this yield by 40 % (160 L). An analysis of dew events is made with meteorological data. It shows that the variable relative humidity is the most important parameter, which in turn is strongly correlated with the average wind direction with respect to monsoon direction. The cumulative dew water yield (6.3 mm) remains modest when compared with the average rain fall (300 mm). But dew occurs far more frequently than rain and it forms precisely during the dry season when water is most scarce.

    Gray Matter Abnormalities in Temporal Lobe Epilepsy: Relationships with Resting-State Functional Connectivity and Episodic Memory Performance.

    Get PDF
    Temporal lobe epilepsy (TLE) affects multiple brain regions through evidence from both structural (gray matter; GM) and functional connectivity (FC) studies. We tested whether these structural abnormalities were associated with FC abnormalities, and assessed the ability of these measures to explain episodic memory impairments in this population. A resting-state and T1 sequences were acquired on 94 (45 with mesial temporal pathology) TLE patients and 50 controls, using magnetic resonance imaging (MRI) technique. A voxel-based morphometry analysis was computed to determine the GM volume differences between groups (right, left TLE, controls). Resting-state FC between the abnormal GM volume regions was computed, and compared between groups. Finally, we investigated the relation between EM, GM and FC findings. Patients with and without temporal pathology were analyzed separately. The results revealed reduced GM volume in multiple regions in the patients relative to the controls. Using FC, we found the abnormal GM regions did not display abnormal functional connectivity. Lastly, we found in left TLE patients, verbal episodic memory was associated with abnormal left posterior hippocampus volume, while in right TLE, non-verbal episodic memory was better predicted by resting-state FC measures. This study investigated TLE abnormalities using a multi-modal approach combining GM, FC and neurocognitive measures. We did not find that the GM abnormalities were functionally or abnormally connected during an inter-ictal resting state, which may reflect a weak sensitivity of functional connectivity to the epileptic network. We provided evidence that verbal and non-verbal episodic memory in left and right TLE patients may have distinct relationships with structural and functional measures. Lastly, we provide data suggesting that in the setting of occult, non-lesional right TLE pathology, a coupling of structural and functional abnormalities in extra-temporal/non-ictal regions is necessary to produce reductions in episodic memory recall. The latter, in particular, demonstrates the complex structure/function interactions at work when trying to understand cognition in TLE, suggesting that subtle network effects can emerge bearing specific relationships to hemisphere and the type of pathology

    Hippocampal functional connectivity patterns during spatial working memory differ in right versus left temporal lobe epilepsy.

    Get PDF
    Temporal lobe epilepsy (TLE), affecting the medial temporal lobe, is a disorder that affects not just episodic memory but also working memory (WM). However, the exact nature of hippocampal-related network activity in visuospatial WM remains unclear. To clarify this, we utilized a functional connectivity (FC) methodology to investigate hippocampal network involvement during the encoding phase of a functional magnetic resonance imaging (fMRI) visuospatial WM task in right and left TLE patients. Specifically, we assessed the relation between FC within right and left hippocampus-seeded networks, and patient performance (rate of correct responses) during the encoding phase of a block span WM task. Results revealed that both TLE groups displayed a negative relation between WM performance and FC between the left hippocampus and ipsilateral parahippocampal gyrus. We also found a positive relationship between performance and FC between the left hippocampus seed and the precuneus, in the right TLE group. Lastly, the left TLE specifically demonstrated a negative relationship between performance and FC between both hippocampi and ipsilateral cerebellar clusters. Our findings indicate that right and left TLE groups may develop different patterns of FC to implement visuospatial WM. Indeed, the present result suggests that FC provides a unique means of identifying abnormalities in brain networks, which cannot be discerned at the level of behavioral output through neuropsychological testing. More broadly, our findings demonstrate that FC methods applied to task-based fMRI provide the opportunity to define specific task-related networks

    Extratemporal functional connectivity impairments at rest are related to memory performance in mesial temporal epilepsy.

    Get PDF
    Mesial temporal lobe epilepsy (MTLE) is the most frequent form of focal epilepsy. At rest, there is evidence that brain abnormalities in MTLE are not limited to the epileptogenic region, but extend throughout the whole brain. It is also well established that MTLE patients suffer from episodic memory deficits. Thus, we investigated the relation between the functional connectivity seen at rest in fMRI and episodic memory impairments in MTLE. We focused on resting state BOLD activity and evaluated whether functional connectivity (FC) differences emerge from MTL seeds in left and right MTLE groups, compared with healthy controls. Results revealed significant FC reductions in both patient groups, localized in angular gyri, thalami, posterior cingulum and medial frontal cortex. We found that the FC between the left non-pathologic MTL and the medial frontal cortex was positively correlated with the delayed recall score of a non-verbal memory test in right MTLE patients, suggesting potential adaptive changes to preserve this memory function. In contrast, we observed a negative correlation between a verbal memory test and the FC between the left pathologic MTL and posterior cingulum in left MTLE patients, suggesting potential functional maladaptative changes in the pathologic hemisphere. Overall, the present study provides some indication that left MTLE may be more impairing than right MTLE patients to normative functional connectivity. Our data also indicates that the pattern of extra-temporal FC may vary as a function of episodic memory material and each hemisphere\u27s capacity for cognitive reorganization

    Increased microstructural white matter correlations in left, but not right, temporal lobe epilepsy.

    Get PDF
    Microstructural white matter tract correlations have been shown to reflect known patterns of phylogenetic development and functional specialization in healthy subjects. The aim of this study was to establish intertract correlations in a group of controls and to examine potential deviations from normality in temporal lobe epilepsy (TLE). We investigated intertract correlations in 28 healthy controls, 21 left TLE (LTLE) and 23 right TLE (RTLE). Nine tracts were investigated, comprising the parahippocampal fasciculi, the uncinate fasciculi, the arcuate fasciculi, the frontoparietal tracts, and the fornix. An abnormal increase in tract correlations was observed in LTLE, while RTLE showed intertract correlations similar to controls. In the control group, tract correlations increased with increasing fractional anisotropy (FA), while in the TLE groups tract correlations increased with decreasing FA. Cluster analyses revealed agglomeration of bilateral pairs of homologous tracts in healthy subjects, with such pairs separated in our LTLE and RTLE groups. Discriminant analyses aimed at distinguishing LTLE from RTLE, revealing that tract correlations produce higher rates of accurate group classification than FA values. Our results confirm and extend previous work by showing that LTLE compared to RTLE patients display not only more extensive losses in microstructural orientation but also more aberrant intertract correlations. Aberrant correlations may be related to pathologic processes (i.e., seizure spread) or to adaptive processes aimed at preserving key cognitive functions. Our data suggest that tract correlations may have predictive value in distinguishing LTLE from RTLE, potentially moving diffusion imaging to a place of greater prominence in clinical practice

    Удосконалення методики підготовки баранів-плідників до взяття сперми

    Get PDF
    The results of studies on the semen production of ram-sires of three European meat breeds, such as texel, oxford down and Vvalais blacknose in the process of preparing for a breeding season or taking semen on an artificial vagina for further use for deep freezing, are presented. During the preparatory period, from each group of rams, 120 ejaculates were obtained, 12 ejaculates in the first and second subperiods, 18 ejaculates in the third and fourth and 60 ejaculates in the fifth subperiod. Differences in the semen production performance of the breeders of the studied breeds were determined. At the end of the preparatory period, the volume of the ejaculate of the rams of the oxford down breed was greater than that of texel by 34.8%, of the valais blacknose sheeps – by 53.1%. When comparing the volume of the ejaculate of the rams of the breed of texel and valais blacknose sheeps, the latter was lower by 12.0%. The concentration of semen in the ejaculate was the highest in the Valais rams and amounted to 3.24 billion/ml, which is 3.9% higher than the oxford down rams, and 14.9% is the texel breed. According to the activity of fresh semen, the difference between the breeds was insignificant and ranged from 2.4 to 4.3%. However, the activity of the frozen-thawed semen varied from 6.4% to 14.0%, the highest among the breeders of the oxford down ‒ 3.65 points, the lowest ‒ 3.20 points in rams of the Valais Blacknose breeds. A slight 2.2 – 4.4% deviation between breeds was noted for the resistance of semen to cryopreservation. The smallest number of cryopreserved semen with acrosome damaged in oxford down breeders was found to be 39.14%, which is 3.5% less than that of texel sheep breed and 6.7% more than that of valais blacknose breed breeders. The conducted researches have experimentally confirmed that indicators of semen productivity of ram-sires are improved in accordance with the term of their preparation. Therefore, to train rams to give semen to artificial vagina before the beginning of the steaming season, or to obtain it for cryopreservation, followed by artificial insemination of sheep, is required after careful preparation of the rams for 50‒60 days, with the provision of optimal conditions of keeping and feeding. The main studied parameters of sperm production of ram-sires in the preparatory period, significantly higher values of volume of ejaculate, activity of fresh and preserved semen, their resistance to freezing and the preservation of acrosomes in the breeders of the oxford don was established. The lowest studied indices were found in rams of the valais blacknose breed. Texel breeders occupy an intermediate position for the indicated indices between the studied breeds.Наведено результати досліджень щодо вивчення спермопродуктивності баранів-плідників трьох м'ясних європейських порід, а саме: тексель, оксфорд доун та валлійська чорноноса у процесі підготовки до парувального сезону або взяття сперми на штучну вагіну з метою подальшого її використання для глибокого заморожування. Впродовж підготовчого періоду від кожної групи баранів одержано по 120 еякулятів: по 12 у першому і другому підперіоді, 18 ‒ у третьому і четвертому та 60 ‒ у п’ятому підперіоді. Встановлено відмінності у показниках спермопродуктивності плідників досліджуваних порід. По завершенні підготовчого періоду об’єм еякуляту баранів породи оксфорд доун був більший від плідників породи тексель на 34,8%, валлійської чорноносої ‒ на 53,1%. При порівнянні об’єму еякуляту баранів породи тексель та валлійської чорноносої, в останньої він був менший на 12,0%. Концентрація сперміїв у еякуляті була найвищою у плідників валлійської чорноносої породи і становила 3,24 млрд/мл, що вище порівняно з баранами породи оксфорд доун на 3,9%, породи тексель ‒ на 14,9%. За активністю свіжоодержаної сперми різниця між породами була незначною і становила від 2,4 до 4,3%. Проте  за активністю деконсервованої сперми відмінність становила від 6,4 до 14,0%, найвищою вона була у плідників породи оксфорд доун ‒ 3,65 бала, найнижчою ‒ 3,20 бала у баранів валлійської чорноносої породи. Відмічено незначні 2,2‒4,4% відхилення між породами за стійкістю сперміїв до кріоконсервування. Виявлено найменшу кількість кріоконсервованих сперміїв з ушкодженою акросомою у плідників породи оксфорд доун ‒ 39,14%, що на 3,5% менше, ніж  у баранів породи тексель та на 6,7% ніж у плідників валлійської чорноносої породи. Проведеними дослідженнями експериментально підтверджено, що показники спермопродуктивності баранів-плідників поліпшуються відповідно до терміну їх підготовки. Тому привчати баранів давати сперму на штучну вагіну до початку парувального періоду  чи одержувати її для кріоконсервування з подальшим використанням для штучного осіменіння овець потрібно після ретельної підготовки баранів протягом 50‒60 днів із забезпеченням оптимальних умов утримання та повноцінної годівлі. Встановлено за основними досліджуваними показниками спермопродуктивності баранів-плідників у підготовчий період значно вищі величини за об'ємом еякуляту, активністю свіжоодержаних і деконсервованих сперміїв, стійкістю їх до заморожування та збереженістю акросом у плідників породи оксфорд доун. Найнижчі досліджувані показники виявлено у баранів валлійської чорноносої породи. Плідники породи тексель займали проміжне місце за вказаними показникам між досліджуваними породами

    Effect of nano based seed treatment insecticides on seed quality in Pigeonpea

    Get PDF
    A laboratory experiment was conducted to know the effect seed treatment with nano insecticides on seed quality of pigeonpea (Cajanus cajan (L.) Millsp.) cv. TS3R. This study was conducted to evaluate the effect of macro and nano insecticides on seed germination and vigour of Pigeonpea. Different recommended seed treatment insecticides viz, malathion, fenvalerate, emamectine benzoate, thiodicarb, sweet flag and neem seed kernel powder insecticides were synthesized to nano form using high energy planetary ball mill. The Pigeonpea seed were treated with different nano insecticides i.e., 10-90 per cent reduction in actual dosage. Among the different treatments studied, seed treated with nano malathion 50 per cent lesser than normal dosage, fenvalerate 60 per cent lesser, thiodicarb 10 per cent lesser, emamectine benzoate 30 per cent lesser, sweetflag 70 per cent lesser, neem seed kernel powder 40 per cent lesser than actual recommended dosage gave significantly higher seed germination (98.0, 98.67, 98.67, 97.0, 99.0 and 98.67 percent) ,less number of abnormal seedlings (1.0, 0.33, 1.0, 1.0, 1.0 and 0.33 per cent) , shoot length (10.13, 9.00, 11.47, 9.50, 10.90 and 10.87 cm), root length (12.56, 12.93, 12.83, 12.60 11.50 and 13.00 cm), seedling dry weight (85.73, 87.40, 88.47, 87.70, 88.60 and 88.27 g) and seedling vigour index (2223, 2164, 2397, 2143, 2217 and 2354) as compared to untreated seeds and macro insecticides. Therefore, it is very clear that nano based insecticides has a significant (0.1 %) impact on the seed quality improvement

    Finding and counting vertex-colored subtrees

    Full text link
    The problems studied in this article originate from the Graph Motif problem introduced by Lacroix et al. in the context of biological networks. The problem is to decide if a vertex-colored graph has a connected subgraph whose colors equal a given multiset of colors MM. It is a graph pattern-matching problem variant, where the structure of the occurrence of the pattern is not of interest but the only requirement is the connectedness. Using an algebraic framework recently introduced by Koutis et al., we obtain new FPT algorithms for Graph Motif and variants, with improved running times. We also obtain results on the counting versions of this problem, proving that the counting problem is FPT if M is a set, but becomes W[1]-hard if M is a multiset with two colors. Finally, we present an experimental evaluation of this approach on real datasets, showing that its performance compares favorably with existing software.Comment: Conference version in International Symposium on Mathematical Foundations of Computer Science (MFCS), Brno : Czech Republic (2010) Journal Version in Algorithmic
    corecore