Cortical idiosyncrasies predict the perception of object size

Perception is subjective. Even basic judgments, like those of visual object size, vary substantially between observers and also across the visual field within the same observer. The way in which the visual system determines the size of objects remains unclear, however. We hypothesize that object size is inferred from neuronal population activity in V1 and predict that idiosyncrasies in cortical functional architecture should therefore explain individual differences in size judgments. Here we show results from novel behavioural methods and functional magnetic resonance imaging (fMRI) demonstrating that biases in size perception are correlated with the spatial tuning of neuronal populations in healthy volunteers. To explain this relationship, we formulate a population read-out model that directly links the spatial distribution of V1 representations to our perceptual experience of visual size. Taken together, our results suggest that the individual perception of simple stimuli is warped by idiosyncrasies in visual cortical organization

Seed yield and quality as influenced by growing conditions in hybrid seed production of bitter gourd (Momordica charantia L.) cv. Pusa Hybrid-1

The present investigation was carried out under insect proof net house (IPN) and open field condition (OFC) at Centre for Protected Cultivation Technology and Seed Testing Laboratory of Division of Seed Science &Technology, IARI, New Delhi in bitter gourd cv. Pusa Hybrid-1 during summer season because under open field condition the seed yield and seed quality of bitter gourd drastically reduced due to viral diseases and fruit fly in kharif and early onset of high temperature, unseasonal rains during summer, which restricts the hybrid seed production of bitter gourd under north Indian condition. The observations on seed yield & quality characters and physical properties of seed were recorded. The quality attributes were evaluated immediately after harvest and after 8 months of ambient storage and their results were compared. The experimental results revealed that total number of seed per fruit (46.7), number of filled seed per fruit (45.3), seed yield per fruit (9.41g), seed yield per plant (27.28g), and seed yield per hectare (232kg) were significantly higher under IPN in comparison to OFC. Among the physical parameters of seed, seed width (0.81cm) & seed coat (0.79g) weight recorded significantly higher in IPN. The seed quality attributes immediately after harvest was also significantly superior under IPN compared to OFC except for germination %. The hybrid seed produced under IPN conditions could maintain their superiority for quality traits even after 8 monthsof its ambient storage. The seed yield and seed quality attributes were comparatively superior under IPN conditions. The seed crop grown under IPN overcomes the threat of insect vectors, viral diseases and unfavourable climatic conditions and helps in attaining the better seed yield and quality

Effect of truss retention and pruning of berry on seed yield and quality of cherry tomato (Solanum lycopersicum var cerasiforme) grown under different polyhouse structures

Study was conducted to evaluate the effect of retention of truss per plant and pruning of berries per truss on seed yield and quality of cherry tomato (Solanum tycopersicum var cerasiforme L.) grown under three different polyhouse structures, viz. semi climate controlled polyhouse (P1), naturally ventilated polyhouse (P2) and insect proof nethouse (P3). Among the structures P1 gave higher berry weight (7.67 g), number of seeds/berry (60.66), 100 seed weight (0.1328 g), seed yield/berry (0.0912 g), germination (84.90%), vigour index-I (650.64), vigour index-II (1.47) and lower EC (0.0086 µS/g/cm), when compared to P2 and P3. The retention of 5 truss per plant (V1) recorded higher berry weight (7.37 g), number of seeds/berry (63.25), 100 seed weight (0.1319 g), seed yield/berry (0.0886 g), germination (84.68 %), vigour index-I (640.97), vigour index-II (1.43) and lower electrical conductivity (0.0083 µS/ g/cm), as compared to V2 and V3. The thinning of berry, i.e 10 per truss (B1) has given significantly higher mean berry weight (8.21 g), number of seeds/berry (61.53), 100 seed weight (0.1323 g), 100 seed weight (0.1323 g), seed yield/berry (0.0913 g), germination (86.01%), vigour index-I (651.96), vigour-II (1.46) and lower EC (0.0080 µS/g/ cm) in comparison to B2 and B3

Morphological characterization of parental lines and cultivated genotypes of bottle gourd (Lagenaria siceraria)

Genetic diversity and relatedness were assessed among fifteen most common commercial bottle gourd [Lagenaria siceraria (Mol.) Standl.] genotypes of public sector institutes in India; the fifteen genotypes were grown in the field for two seasons under RCBD with three replications in New Delhi condition. Data were collected on morphological features of bottle gourd which include vine, leaf, flower, fruit and seed characteristics. A descriptor list with selected 32 morphological (qualitative and quantitative) characters were adopted from NBPGR guidelines and used for characterization. The data was used to calculate genetic similarity and to construct a dendrogram using the unweighted pair-group method with arithmetic average (UPGMA). Data on quantitative characters was subjected to ANOVA using SAS and effects declared significant at 5% level. The procedure PRINCOMP was then used to perform a principle component (PC) analysis using fourteen quantitative variables and genotypes plotted on two dimensions using the first two principle components (PC1 and PC2). The results of quantitative characters of Pusa Santusti, Pusa Sandesh and Arka Bahar demonstrated highly significant variation between genotypes. Results of the principle component analyses for the traits indicated that the first five PCs explained a total of 80% of the total variation. The high morphological diversity observed among public sector genotypes emphasizes the need to expand the genetic base of the cultivated bottle gourd in India

Effect of post-harvest ripening and drying methods on seed quality and storability in pumpkin cv Pusa Hybrid 1

An investigation was carried out, to study the effect of post-harvest ripening and drying methods on the seed quality in pumpkin cv Pusa Hybrid 1, during summer 2008 and 2009 at Seed Production Unit, IARI, New Delhi. After harvesting, the fruits were allowed for post-harvest ripening (PHR) of zero days (P0), 10 days (P1) and 20 days (P2) and seeds obtained from each of the PHR treatments were subjected to three methods of drying, viz. shade drying (D1), sun drying (D2) and mechanical drying (D3). The results showed that seed obtained from 20 days PHR followed by shade drying (P2D1) had given superior quality seed with respect to germination (94.33 %), seedling length (34.30 cm), vigour index - I (3236.52) and electrical conductivity (17.30 m mhos/cm/g) followed by P2D3 (20 days PHR and mechanical drying), while germination (%) was significantly lower in PoD2 during storage. In all treatments the seeds stored for 12 months showed maximum germination followed by reduction after eighteen months of storage. The germination percentage was maintained above the Indian minimum seed certification standards (IMSCS) of 60% up to eighteen months of storage in all treatments

Effect of growing conditions on seed yield and quality of cucumber (Cucumis stivus) hybrid

The present investigation was carried out at Centre for Protected Cultivation Technology (CPCT) farm at Indian Agricultural Research Institute (IARI), New Delhi during summer and kharif seasons 2011 under naturally ventilated polyhouse, insect proof net house and open field conditions to study the influence of different growing conditions on seed yield and quality of cucumber (Cucumis sativus) hybrid (Cv Pant Shankar Khira 1) seed production. The seed parent and pollen parent were grown in 3:1 ratio. Water and nutrients were provided through drip fertigation in all three conditions. In all three growing conditions, vine length and number of leaf nodes were significantly more in kharif season compared to summer season. Number of fruit developed to maturity was significantly more in kharif (2.15) than summer (1.90). The vine length, number of leaves, fruit weight, fruit length and fruit width were significantly higher under naturally ventilated polyhouse and insect proof net house compared to open field in both of the seasons. The number of seeds/fruit was significantly higher in insect proof net house (204.15) and naturally ventilated polyhouse (188.35) as compared to open condition (126.05). The seed yield/fruit, seed yield/plant and seed yield per 1000 m2 were significantly higher in kharif season as compared to summer. Whereas higher seed yield was recorded in insect proof net house followed by naturally ventilated polyhouse and open field condition. The seed quality attributes, viz. germination percentage, seedling length, seedling dry weight, vigour index I and II and seed moisture content immediately after harvest were also significantly superior in naturally ventilated polyhouse and insect proof net house in comparison to open field conditions. The benefit-cost ratio (BCR) is higher in insect proof net house (1:2.25) followed by open condition (1:1.12) naturally ventilated polyhouse (1:0.37)

Physiological maturity and its influence on seed yield and quality in cucumber (Cucumis sativus) under different growing environments

To study the physical and physiological changes occurred during maturation in fruit and seeds of cucumber (Cucumis sativus L.) (cv. Pant Shankar Khira-1) grown under naturally ventilated polyhouse, insect proof net house and open field conditions at Centre for Protected Cultivation Technology (CPCT) farm, Indian Agricultural Research Institute (IARI), New Delhi during summer and kharif seasons 2011. The fruits were harvested at 25, 30, 35, 40 and 45 days from anthesis (DFA) and seeds were extracted following fermentation. Various physical parameters, viz. fruit weight, fruit length, fruit width, number of filled seeds, number of unfilled seeds, 100 seed weight, seed yield/fruit, seed fresh weight, seed dry weight were recorded. The physiological maturity was evaluated by germinating seeds before and after drying. There were only small, non-significant difference in germinability among seed harvested at 35, 40 and 45 DFA, all of which were of higher quality than seeds which had been harvested at 25 and 30 DFA. The analysis of data showed that the seeds attained physiological maturity at 35 DFA under naturally ventilated poly house and insect proof net house, whereas at 40 DFA under open field condition

The optimal experimental design for multiple alternatives perceptual search

Perceptual bias is inherent to all our senses, particularly in the form of visual illusions and aftereffects. However, many experiments measuring perceptual biases may be susceptible to nonperceptual factors, such as response bias and decision criteria. Here, we quantify how robust multiple alternative perceptual search (MAPS) is for disentangling estimates of perceptual biases from these confounding factors. First, our results show that while there are considerable response biases in our four-alternative forced-choice design, these are unrelated to perceptual biases estimates, and these response biases are not produced by the response modality (keyboard vs. mouse). We also show that perceptual bias estimates are reduced when feedback is given on each trial, likely due to feedback enabling observers to partially (and actively) correct for perceptual biases. However, this does not impact the reliability with which MAPS detects the presence of perceptual biases. Finally, our results show that MAPS can detect actual perceptual biases and is not a decisional bias towards choosing the target in the middle of the candidate stimulus distribution. In summary, researchers conducting a MAPS experiment should use a constant reference stimulus, but consider varying the mean of the candidate distribution. Ideally, they should not employ trial-wise feedback if the magnitude of perceptual biases is of interest

Study of water supply & sanitation practices in India using geographic information systems: some design & other considerations in a village setting

Background & objectives: Availability of clean water and adequate sanitation facilities are of prime importance for limiting diarrhoeal diseases. We examined the water and sanitation facilities of a village in southern India using geographic information system (GIS) tools. Methods: Places of residence, water storage and distribution, sewage and places where people in the village defaecated were mapped and drinking water sources were tested for microbial contamination in Nelvoy village, Vellore district, Tamil Nadu. Results: Water in the village was found to be microbiologically unfit for consumption. Analysis using direct observations supplemented by GIS maps revealed poor planning, poor engineering design and lack of policing of the water distribution system causing possible contamination of drinking water from sewage at multiple sites. Interpretation & conclusions: Until appropriate engineering designs for water supply and sewage disposal to suit individual village needs are made available, point-of-use water disinfection methods could serve as an interim solution

Mutation analysis of the BRCA1 gene in Malaysian breast cancer patients

Thirty patients with early onset breast cancer or familial breast cancer from Malaysia were analysed for germline mutation in the early onset breast cancer I gene (BRCA1). Direct sequencing of the entire coding region of BRCA1 identified a frameshift mutation, c.5447-5448insC (insC5447) (codon 1776 of exon 21) in a patient aged 32 of the Malay ethnic origin, who had no family history of breast and/or ovarian cancer. Eight polymorphisms (2201C > T, 2430T > C, P871L, E1038G, K1183R, 4427T > C, S1613G and IVS8-57delT) were identified in the samples tested