V1 V2 V3 Research Articles

Functional connectivity via total correlation: Analytical results in visual areas

Recent studies invoke the superiority of the multivariate Total Correlation concept over the conventional pairwise measures of functional connectivity in biological networks. Those seminal works certainly show that empirical measures of Total Correlation lead to connectivity patterns that differ from what is obtained using the most popular measure, linear correlation, or its higher order and nonlinear alternative Mutual Information. However, they do not provide analytical results that explain the differences beyond the obvious multivariate versus bivariate definitions. Moreover, the accuracy of the empirical estimators could not be addressed directly because no controlled scenario with known analytical result was provided either. This point is critical because empirical estimation of information theory measures is always challenging.As opposed to previous empirical approaches, in this work we present analytical results to prove the advantages of Total Correlation over Mutual Information to describe the functional connectivity. In particular, we do it in neural networks for early vision (retina–LGN–cortex) which are realistic but simple enough to get analytical results. The presented analytical setting is also useful to check empirical estimates of Total Correlation. Therefore, once certain estimate can be trusted, one can explore the behavior with natural signals where the analytical results (that assume Gaussian signals), may not be valid. In this regard, as applications (a) we explore the effect of connectivity and feedback in the analytical retina–LGN–cortex network with natural images, and (b) we assess the functional connectivity in visual areas V1–V2–V3–V4 from actual fMRI recordings.

ID: 215463 Cortical Stimulation in Severe Refractory Trigeminal Neuralgia: Case Report

Female patient, 37 years old, with right trigeminal neuralgia V1 V2 V3 since 2018. Started with pharmacological treatment with carbamazepine 1600 mg/d, without response. In January 2019 she was examined in another institution, and a neurovascular decompressive surgery (janetta) was performed, with poor response. April 2019 we performed Gasserian Ganglion Compression with poor result. August 2019 we performed radiofrequency ablation without response. In May 2021 she underwent for another neurovascular decompressive surgery, with poor results and recurring pain in the 3 branches.

Pertumbuhan dan Hasil Kandungan Fe dan Zn pada Beras dari Kultivar Padi Ladang di Kabupaten Timor Tengah Utara

Field rice (paddy field) is one of the important crops/commodities and is an integral part of the dry land farming system in North Central Timor district. The content of rice is to meet the needs of carbohydrates in the body. The materials used are harvested grain from the local North Central Timor rice cultivar which has been carried out for the 2022 planting season. A total of 6 field rice in North Central Timor district were to be tested for Fe and Zn content. Grain samples were taken from crops grown in the same season and location, namely in the dry season of 2022. This study aims to identify local Timorese rice varieties that have high and stable Fe and Zn contents. The study was conducted in the Field Laboratory of the Faculty of Agriculture, University of Timor with a non-factorial Randomized Block Design consisting of 6 cultivar treatments V1 V2 V3 V4 V5 and V6 and the XRF Laboratory, BB Padi Sukamandi. Test the content of Fe and Zn using an XRF machine with an x-ray based performance system. A total of 6 types of field rice were tested for the content of Fe and Zn in brown and polished rice and repeated in duplicate. The content of Fe and Zn is expressed in units of ppm. Data processing was carried out using Excel and SAS 9 software. The results showed that there were differences in the growth and production components between the local Timor and East Timor upland rice cultivars. Cultivars with cultivar V2 (muit fua naek) productivity as seen from the t/ha yield of 3.20 tons per ha were significantly higher than the other cultivars. The results of the analysis of Fe and Zn content showed that cultivar V6 (Aen Mael) had the highest Fe content of 15.1 among the other cultivars, and the lowest was cultivar V4 (Aen Ek ELo) which had an Fe content of 13.0. The highest Zn content was in cultivar V5 (Aen Muit Fua Ana) with a Zn content of 27.9 while the lowest was in cultivar V2 (Muit Fua Naek) with a Zn content of 20.4.

Hypervariable Regions in 16S rRNA Genes for the Taxonomic Classification

16S ribosomal RNA (rRNA) gene sequences are reliable markers for the taxonomic classification of microbes and widely used in environmental microbiology. Production of 16S rRNA gene amplicons in large amounts, encompassing the full length of genes is not yet feasible, because of the limitations of the current sequencing techniques. They are mostly in short reads of length less than 300 base pairs. Hence, the selection of the most efficient hypervariable regions for phylogenetic analysis and taxonomic classification is a current research area. It is found that nine hypervariable regions (V1–V9), resides in bacterial 16S ribosomal RNA (rRNA) genes. Family, genus, and species-specific sequences within a given hypervariable region constitute useful targets for diagnostic assays and other scientific investigations. In this study systematic studies that compare the relative advantage of hypervariable regions grouped as V1–V2–V3, V4–V5–V6, and V7–V8–V9 for specific diagnostic goals are done. In the present research, the built in function Longest–Common–Subsequence in computer algebra package MATHEMATICA is used to create an in silico pipeline to evaluate the taxonomic classification sensitivity of the hypervariable regions compared with the corresponding full-length sequences. Conclusions: Our results suggest that V4–V5–V6 region might be an optimal sub-region for the design of universal primers with superior phylogenetic resolution for bacterial phyla.

Infrared Spectroscopy of Disilicon-Carbide, Si2C: The ν3 Fundamental Band

The ν3 antisymmetric stretching mode of disilicon-carbide, Si2C, was studied using a narrow line width infrared quantum cascade laser spectrometer operating at 8.3 μm. The Si2C molecules were produced in an Nd:YAG laser ablation source from a pure silicon sample with the addition of a few percent methane diluted in a helium buffer gas. Subsequent adiabatic expansion was used to cool the gas down to rotational temperatures of a few tens of kelvin. A total of 183 infrared transitions recorded in the spectral range between 1200 and 1220 cm-1 were assigned to the fundamental ν3 mode of Si2C. In addition, pure rotational transitions of Ka = 1 and 2 between 278 and 375 GHz were recorded using a supersonic jet spectrometer for submillimeter wavelengths. Molecular parameters for the ( v1 v2 v3) = (001) vibrationally excited state were derived and improved molecular parameters for the vibrational ground-state (000) were obtained from a global fit data analysis, which includes our new laboratory data and millimeter wavelength data from the literature. We found the rotational levels Ka = 0 and Ka = 2 in the vibrationally excited (001) state being perturbed by a Coriolis-type interaction with energetically close lying levels of the symmetric stretching and triple-excited bending mode (130). The data analysis was supported by quantum chemical calculations performed at the coupled-cluster level of theory. All experimental results were found to be in excellent agreement with the theory.

Microbial community profiling of fresh basil and pitfalls in taxonomic assignment of enterobacterial pathogenic species based upon 16S rRNA amplicon sequencing

Application of 16S rRNA (gene) amplicon sequencing on food samples is increasingly applied for assessing microbial diversity but may as unintended advantage also enable simultaneous detection of any human pathogens without a priori definition. In the present study high-throughput next-generation sequencing (NGS) of the V1–V2–V3 regions of the 16S rRNA gene was applied to identify the bacteria present on fresh basil leaves. However, results were strongly impacted by variations in the bioinformatics analysis pipelines (MEGAN, SILVAngs, QIIME and MG-RAST), including the database choice (Greengenes, RDP and M5RNA) and the annotation algorithm (best hit, representative hit and lowest common ancestor). The use of pipelines with default parameters will lead to discrepancies. The estimate of microbial diversity of fresh basil using 16S rRNA (gene) amplicon sequencing is thus indicative but subject to biases.Salmonella enterica was detected at low frequencies, between 0.1% and 0.4% of bacterial sequences, corresponding with 37 to 166 reads. However, this result was dependent upon the pipeline used: Salmonella was detected by MEGAN, SILVAngs and MG-RAST, but not by QIIME. Confirmation of Salmonella sequences by real-time PCR was unsuccessful. It was shown that taxonomic resolution obtained from the short (500bp) sequence reads of the 16S rRNA gene containing the hypervariable regions V1–V3 cannot allow distinction of Salmonella with closely related enterobacterial species.In conclusion 16S amplicon sequencing, getting the status of standard method in microbial ecology studies of foods, needs expertise on both bioinformatics and microbiology for analysis of results. It is a powerful tool to estimate bacterial diversity but amenable to biases. Limitations concerning taxonomic resolution for some bacterial species or its inability to detect sub-dominant (pathogenic) species should be acknowledged in order to avoid overinterpretation of results.

Mirror-symmetry protected non-TRIM surface state in the weak topological insulator Bi2TeI.

Strong topological insulators (TIs) support topological surfaces states on any crystal surface. In contrast, a weak, time-reversal-symmetry-driven TI with at least one non-zero v1, v2, v3 ℤ2 index should host spin-locked topological surface states on the surfaces that are not parallel to the crystal plane with Miller indices (v1 v2 v3). On the other hand, mirror symmetry can protect an even number of topological states on the surfaces that are perpendicular to a mirror plane. Various symmetries in a bulk material with a band inversion can independently preordain distinct crystal planes for realization of topological states. Here we demonstrate the first instance of coexistence of both phenomena in the weak 3D TI Bi2TeI which (v1 v2 v3) surface hosts a gapless spin-split surface state protected by the crystal mirror-symmetry. The observed topological state has an even number of crossing points in the directions of the 2D Brillouin zone due to a non-TRIM bulk-band inversion. Our findings shed light on hitherto uncharted features of the electronic structure of weak topological insulators and open up new vistas for applications of these materials in spintronics.

Stress-induced QTc-interval shortening as an ancillary marker of ischemia in patients with complete left bundle branch block

In patients with left bundle branch block (LBBB), ischemia-induced repolarization changes associated with QTc-interval shortening may be recorded during coronary angioplasty. We aimed to assess whether these repolarization changes may be predictive of severe coronary artery disease in patients with LBBB. Fifty noninfarcted LBBB patients underwent dipyridamole stress test and coronary angiography for chest pain. To localize the site of ischemia, we considered four groups of conventional ECG leads (V1-V2-V3; V4-V5-V6; aVL-I; III-aVF-II), exploring the anteroseptal, lateral, high-lateral, and inferior left ventricular walls. ST-T changes and QTc intervals were estimated at rest and peak stress, lead by lead, in each group of leads and the fractional percentage difference between rest-stress QTc intervals ([DELTA]QTc) was calculated. A [DELTA]QTc greater than -10% was used to define significant QTc-interval shortening. Coronary stenosis of more than 70% and more than 90% were considered 'significant' and 'severe'. According to dipyridamole stress test response, two groups were identified: group I (35 patients) with dipyridamole-induced ischemia and group II (15 patients) without dipyridamole-induced ischemia. The wall motion score index at peak stress (compared with resting wall motion score index) was significantly higher in group I (1.98 +/- 0.13 vs. 1.28 +/- 0.08, P < 0.0001) than in group II (1.36 +/- 0.18 vs. 1.25 +/- 0.08, P = 0.296). The patients of group I showed a significant QTc-interval shortening ([DELTA]QTc = -16.9 +/- 3.9%), whereas this did not happen in patients of group II ([DELTA]QTc = +8.8 +/- 2.4%, P < 0.0001). The patients of group I also had a more severe stenosis in the vessel related to the stress-induced dyssynergic area (I = 90.5 +/- 9.5 vs. II = 34.3 +/- 31.1%; P < 0.0001). In patients with LBBB, stress-induced pseudonormalization pattern, associated with QTc-interval shortening, allows the identification of cardiac areas supplied by severely stenosed coronary arteries.

Standing Waves and Traveling Waves Distinguish Two Circuits in Visual Cortex

The visual cortex represents stimuli through the activity of neuronal populations. We measured the evolution of this activity in space and time by imaging voltage-sensitive dyes in cat area V1. Contrast-reversing stimuli elicit responses that oscillate at twice the stimulus frequency, indicating that signals originate mostly in complex cells. These responses stand clear of the noise, whose amplitude decreases as 1/frequency, and yield high-resolution maps of orientation preference and retinotopy. We first show how these maps are combined to yield the responses to focal, oriented stimuli. We then study the evolution of the oscillating activity in space and time. In the orientation domain, it is a standing wave. In the spatial domain, it is a traveling wave propagating at 0.2-0.5 m/s. These different dynamics indicate a fundamental distinction in the circuits underlying selectivity for position and orientation, two key stimulus attributes.

Sequence of pattern onset responses in the human visual areas: an fMRI constrained VEP source analysis

We measured the timing of activity in distinct functional areas of the human visual cortex after onset of a visual pattern. This is not possible with visual evoked potentials (VEPs) or magnetic fields alone, and direct combination of functional magnetic resonance imaging (fMRI) with electromagnetic data has turned out to be difficult. We tested a relatively new approach, where both position and orientation of the active cortex was given to the VEP source model. Subjects saw the same visual patterns flashed ON and OFF, both when recording VEPs and fMRI responses. We identified the positions and orientations of the activated cortex in four retinotopic areas in each individual, and the corresponding dipoles were seeded to model the individual evoked potential data. Unexplained variance, comprising signals from other areas, was inversely modeled. Despite the partially a priori fixed model and optimized signal-to-noise ratio of VEP data, full separation of retinotopic areas was only seldom possible due to crosstalk between the adjacent sources, but separation was usually possible between areas V1 and V3/V3a. Whereas the latencies generally followed the hierarchical organization of cortical areas (V1–V2–V3), with around 25 ms between the strongest responses, an early activation emerged 10–20 ms after V1, close to the temporo-occipital junction (LO/V5) and with an additional 20-ms latency in the corresponding region of the opposite hemisphere. Our approach shows that it is feasible to directly seed information from fMRI to electromagnetic source models and to identify the components and dynamics of VEPs in different retinotopic areas of a human individual.

The V1–V2–V3 complex: quasiconformal dipole maps in primate striate and extra-striate cortex

The mapping function w=k log(z+a) is a widely accepted approximation to the topographic structure of primate V1 foveal and parafoveal regions. A better model, at the cost of an additional parameter, captures the full field topographic map in terms of the dipole map function w=k log[(z+a)/(z+b)]. However, neither model describes topographic shear since they are both explicitly complex-analytic or conformal. In this paper, we adopt a simple ansatz for topographic shear in V1, V2, and V3 that assumes that cortical topographic shear is rotational, i.e. a compression along iso-eccentricity contours. We model the constant rotational shear with a quasiconformal mapping, the wedge mapping. Composing this wedge mapping with the dipole mapping provides an approximation to V1, V2, and V3 topographic structure, effectively unifying all three areas into a single V1–V2–V3 complex using five independent parameters. This work represents the first full-field, multi-area, quasiconformal model of striate and extra-striate topographic map structure.

933-99 Chronic Hydralazine or Enalapril Normalize Myosin Isoforms in the Spontaneously Hypertensive Rat, but Only Enalapril Normalizes Left Ventricular Mass

Increased V3 myosin isoform is seen in left ventricular (LV) hypertrophy (H), but reversion to V1 with chronic afterload reduction and LVH regression is not well defined. We randomized SHR at 3–4 months to oral hydralazine (25 mg/kg), enalapril (40 mg/kg), or placebo. Age matched Wistar Kyoto rats were controls. Group average systolic blood pressure (mmHg) at baseline was 207 (Plac), 223 (Hydrl), 225 (Enal), and 156 (Cntrl). Rats were studied after 3 months of treatment. Echocardiographic LVmass (LVM) was from the cubic function: LVM (mg) = 1.04[(EDD + PWT + IVS) 3 – EDD 3 ], corrected for body weight (LVMI), since echocardiography permits better identification of differing patterns of hypertrophy. Terminal hemodynamics were volumetric aortic flow (mean: MAF, ml/min) and Millar aortic pressure (mean: MAP). Systemic arterial resistance (SAR) and LV contractility (+dp/dt) was derived from digitized waveforms. Following termination, LV was harvested and frozen at –800° C, and myosin isoforms were determined by gel electrophoresis, with expression of V1, V2, V3 isoforms as % total. Analysis of variance was performed and group mean values are given below: Group N MAP MAF SAR +DP/DT LVMI V1 V2 V3 Placebo 17 151 * 105 * 1.57 * 16246 * 2.98 ns 32 * 23 45 * Hydralazine 18 104 164 0.67 8562 2.80 68 15 17 Enalapril 13 94 144 0.68 8633 2.19 # 80 11 9 Control 11 85 179 0.49 13022 2.55 60 15 25 * p &lt; 05, placebo vs Hydrl, and vs Enal # p &lt; 0.05 placebo vs Enal Thus, myosin isoform expression reverted to an adult pattern, in response to long term afterload reduction. Changes in myosin transcriptional patterns however, require additional assessment. Eccentric hypertrophy accounted for persistent LVMI following hydralazine, whereas greater LVMI reduction occurred with ACE inhibition. This suggests that factors other than afterload reduction contribute to LVMI regression with ACE inhibition.

Euclidean geometry from classical mechanics

Euclidean geometry is axiomatic in classical mechanics. In our paper, we have reversed the traditional roles of geometry and mechanics to obtain elegant results in Euclidean geometry. The convex or barycentric coordinates (α1, α2, α3) of point ? in the closed triangular region ?V1 V2V3 may be interpreted as weights α1, α2, α3 which, when placed at the vertices V1 V2 V3 respectively, determine ? as the balance point. Taking Archimedes' Law of Levers as our axiom, we obtain the convex coordinates for various special points of ?V1 V2 V3. Among these special points are the centroid, incenter, Gergonne point, and Nagel point. We then describe the construction of a uniform, calibrated plyboard triangle which serves as a physical model for ?V1 V2 V3. At each vertex, V1 we can suspend a weight Wi. By the proper selection of weights ?W1 W2 W3 we can move the balance point ? to any desired point of the interior of the triangle. The model serves as an excellent teaching device which emphasizes in a striking manner t...

Effect of speaking rate on jaw movements in vowel sequences.

The purpose of this experiment is to study the effect of the speaking rate on the articulatory movements of jaw. Two subjects read a list of nonsense words of the form /V1 V2 V3/, where V1 and V3 were all possible combination of /i, o, e/ and V2 was one ofthe five vowels /i, u, o, a, e/. We measured articulatory dynamics (displacement, transition time and velocity) of jaw movements at the two speaking rates and estimated dynamic characteristics of jaw articulatory system. The results of this study show that the adjustments of speaking rate were achieved by the different strategies between the subjects: with the increase in speaking rate, (1) the velocity of movement did not change, but the articulatory displacement was decreased, and (2) the velocity was increased and the displacement did not vary. The effect of speaking rate on the magnitude of articulatory efforts was clearly observed during the closing movements. The subject who demonstrated rapid movement at the fast speaking rate might increase the articulatory force in the jaw muscular system.