Objective The purpose of this study was to compare the results of the three food-cue paradigms most commonly used for functional neuroimaging studies to determine: i) commonalities and differences in the neural response patterns by paradigm; and, ii) the relative robustness and reliability of responses to each paradigm. Design and Methods functional magnetic resonance imaging (fMRI) studies using standardized stereotactic coordinates to report brain responses to food cues were identified using on-line databases. Studies were grouped by food-cue modality as: i) tastes (8 studies); ii) odors (8 studies); and, iii) images (11 studies). Activation likelihood estimation (ALE) was used to identify statistically reliable regional responses within each stimulation paradigm. Results Brain response distributions were distinctly different for the three stimulation modalities, corresponding to known differences in location of the respective primary and associative cortices. Visual stimulation induced the most robust and extensive responses. The left anterior insula was the only brain region reliably responding to all three stimulus categories. Conclusions These findings suggest visual food-cue paradigm as promising candidate for imaging studies addressing the neural substrate of therapeutic interventions.

The assumption that the Universe, on sufficiently large scales, is homogeneous and isotropic is crucial to our current understanding of cosmology. In this paper we test if the observed galaxy distribution is actually homogeneous on large scales. We have carried out a multifractal analysis of the galaxy distribution in a volume limited subsample from the SDSS DR6. This considers the scaling properties of different moments of galaxy number counts in spheres of varying radius $r$ centered on galaxies. This analysis gives the spectrum of generalized dimension $D_q(r)$, where $q >0$ quantifies the scaling properties in overdense regions and $q<0$ in underdense regions. We expect $D_q(r)=3$ for a homogeneous, random point distribution. In our analysis we have determined $D_q(r)$ in the range $-4 \le q \le 4$ and $7 \le r \le 98 h^{-1} {\rm Mpc}$. In addition to the SDSS data we have analysed several random samples which are homogeneous by construction. Simulated galaxy samples generated from dark matter N-body simulations and the Millennium Run were also analysed. The SDSS data is considered to be homogeneous if the measured $D_q$ is consistent with that of the random samples. We find that the galaxy distribution becomes homogeneous at a length-scale between 60 and $70 h^{-1} {\rm Mpc}$. The galaxy distribution, we find, is homogeneous at length-scales greater than $70 h^{-1} {\rm Mpc}$. This is consistent with earlier works which find the transition to homogeneity at around $70 h^{-1} {\rm Mpc}$.Comment: 6 pages, 3 figures, Submitted for publicatio

Using Shapefinders, which are ratios of Minkowski functionals, we study the morphology of neutral hydrogen (HI) density fields, simulated using semi-numerical technique (inside-out), at various stages of reionization. Accompanying the Shapefinders, we also employ the 'largest cluster statistic' (LCS), originally proposed in Klypin & Shandarin (1993), to study the percolation in both neutral and ionized hydrogen. We find that the largest ionized region is percolating below the neutral fraction x HI 0.728 (or equivalently z 9). The study of Shapefinders reveals that the largest ionized region starts to become highly filamentary with non-trivial topology near the percolation transition. During the percolation transition, the first two Shapefinders -'thickness' (T ) and 'breadth' (B) -of the largest ionized region do not vary much, while the third Shapefinder -'length' (L) -abruptly increases. Consequently, the largest ionized region tends to be highly filamentary and topologically quite complex. The product of the first two Shapefinders, T ×B, provides a measure of the 'cross-section' of a filament-like ionized region. We find that, near percolation, the value of T × B for the largest ionized region remains stable at ∼ 7 Mpc 2 (in comoving scale) while its length increases with time. Interestingly all large ionized regions have similar cross-sections. However, their length shows a power-law dependence on their volume, L ∝ V 0.72 , at the onset of percolation.

Lineages of the generalist hemipteran herbivore Myzus persicae (green peach aphid) that have expanded their host range to include tobacco often have elevated nicotine tolerance. The tobacco-adapted M. persicae lineage used in this study was able to reproduce on nicotine-containing artificial diets at concentrations that were 15-fold higher than those that were lethal to a non-adapted M. persicae lineage. Fecundity of the nicotine-tolerant M. persicae lineage was increased by 100 μM nicotine in artificial diet, suggesting that this otherwise toxic alkaloid can serve as a feeding stimulant at low concentrations. This lineage also was pre-adapted to growth on tobacco, exhibiting no drop in fecundity when it was moved onto tobacco from a different host plant. Although growth of the non-tobacco-adapted M. persicae lineage improved after three generations on tobacco, this higher reproductive rate was not associated with increased nicotine tolerance. M. persicae gene expression microarrays were used to identify transcripts that are up-regulated in response to nicotine in the tobacco-adapted lineage. Induced expression was found for CYP6CY3, which detoxifies nicotine in M. persicae, other genes encoding known classes of detoxifying enzymes, as well as genes encoding secreted M. persicae salivary proteins.

Here we report the discovery of an extremely massive and large supercluster (called Saraswati a) ) found in the Stripe 82 region of SDSS. This supercluster is a major concentration of galaxies and galaxy clusters, forming a wall-like structure spanning at least 200 Mpc across at the redshift z ≈ 0.3. This enormous structure is surrounded by a network of galaxy filaments, clusters, and large, ∼ 40−170 Mpc diameter, voids. The mean density contrast δ (relative to the background matter density of the universe) of Saraswati is 1.62 and the main body of the supercluster comprises at least 43 massive galaxy clusters (mean z = 0.28) with a total mass of ∼ 2×1016 M ⊙ . The spherical collapse model suggests that the central region of radius ∼ 20 Mpc and mass at least 4 × 10 15 M ⊙ may be collapsing. This places it among the few largest and most massive superclusters known, comparable to the most massive 'Shapley Concentration' (z ≈ 0.046) in the nearby universe. The Saraswati supercluster and its environs reveal that some extreme large-scale, prominent matter density enhancements had formed ∼ 4 Gy in the past when dark energy had just started to dominate structure formation. This galactic concentration sheds light on the role of dark energy and cosmological initial conditions in supercluster formation, and tests the competing cosmological models.

Minkowski functionals and Shapefinders shed light on the connectedness of large-scale structure by determining its topology and morphology. We use a sophisticated code, SURFGEN2, to measure the Minkowski functionals and Shapefinders of individual clusters by modelling cluster surfaces using the Marching Cube 33 triangulation algorithm. In this paper, we study the morphology of simulated neutral hydrogen (HI) density fields using Shapefinders at various stages of reionization from the excursion set approach. Accompanying the Shapefinders, we also employ the 'largest cluster statistic' (LCS) to understand the percolation process. Percolation curves demonstrate that the non-Gaussianity in the HI field increases as reionization progresses. The large clusters in both the HI overdense and underdense excursion sets possess similar values of "thickness" (T ), as well as "breadth" (B), but their third Shapefinder -"length" (L) -becomes almost proportional to their volume. The large clusters in both HI overdense and underdense segments are overwhelmingly filamentary. The 'cross-section' of a filamentary cluster can be estimated using the product of the first two Shapefinders, T × B. Hence the cross sections of the large clusters at the onset of percolation do not vary much with volume and their sizes only differ in terms of their lengths. This feature appears more vividly in HI overdense regions than in underdense regions and is more pronounced at lower redshifts which correspond to an advanced stage of reionization.

Background:Out of those who attempted self-harm and survived, many actually wanted to die and many did not. Presently, no distinctive nomenclature exists for these two groups, which causes difficulty in understanding as well as in management and research.Aim:To study whether there exist two such groups which are distinct and can be differentiated clinically.Methods:Seventy-eight persons who attempted self-harm were evaluated in detail by a psychiatrist. The data were recorded in an especially designed proforma which documented sociodemographic variables, psychiatric and physical illnesses, psychosocial stress factors, substance abuse, past and family history and details of suicide attempt.Results:Two groups emerged with distinct characteristics. The two groups were different in factors such as age, diagnosis, intentionality, lethality, mode, motive to kill oneself, past/family history, relation to stress, personality traits and precaution to prevent detection before and/or after the act. The group which had persons who really wanted to die but survived is suggested to be named as the ‘failed suicide’ group and the other group which had persons who did not actually want to die is suggested to be named as the ‘deliberate self-harm’ group.Conclusion:Those who cause harm to themselves but survive can be distinctly put into two groups: (i) the ‘failed suicide’ group constituting those who actually wanted to kill themselves and (ii) the ‘deliberate self-harm’ group constituting those who did not actually want to die. The criteria for distinctions are suggested.

It is now well accepted that the galaxies are distributed in filaments, sheets and clusters all of which form an interconnected network known as the Cosmic Web. It is a big challenge to quantify the shapes of the interconnected structural elements that form this network. Tools like the Minkowski functionals which use global properties, though well suited for an isolated object like a single sheet or filament, are not suited for an interconnected network of such objects. We consider the Local Dimension $D$, defined through $N(R)=A R^D$, where $N(R)$ is the galaxy number count within a sphere of comoving radius $R$ centered on a particular galaxy, as a tool to locally quantify the shape in the neigbourhood of different galaxies along the Cosmic Web. We expect $D \sim 1,2$ and 3 for a galaxy located in a filament, sheet and cluster respectively. Using LCDM N-body simulations we find that it is possible to determine $D$ through a power law fit to $N(R)$ across the length-scales 2 to $10 {\rm Mpc}$ for $\sim 33 %$ of the galaxies. We have visually identified the filaments and sheets corresponding to many of the galaxies with $D \sim 1$ and 2 respectively. In several other situations the structure responsible for the $D$ value could not be visually identified, either due to its being tenuous or due to other dominating structures in the vicinity. We also show that the global distribution of the $D$ values can be used to visualize and interpret how the different structural elements are woven into the Cosmic Web.Comment: 5 pages, 6 figure, Accepted for Publication to MNRAS-lette