Walkable Neighborhood Systems

This essay defines walkable neighborhood systems, summarizes the negative impacts of suburbia on the economy as a whole, and presents indirect pricing as a major cause of suburbia. The paper proposes several pricing reforms and green mobility as solutions based on prices that reflect full costs. Several hypotheses are presented concerning the performance of walkable neighborhood systems and the concept of an inflection point for the takeoff of non‐auto modes when density within a walkable area reaches economies of scale. It proposes research on old neighborhoods as a way to quantify relationships in the absence of pricing reforms. The paper discusses building types and high rise, and how at highest densities there may be diminishing returns. While it is natural for most scholars to study dominant land uses, there is a need to understand better dense walking neighborhoods as solutions to the costs of suburbia and to enhance their functioning to show a path to a sustainable future.     

Effect of three different oil cake-based diets on pond production performance of silver barb, Puntius gonionotus (Bleeker)

One of the three iso-nitrogenous (30% crude protein) and iso-energetic (15.0 MJ kg⁻¹ diet) oil cake-based diets (groundnut, D-1; soybean, D-2 and mustard, D-3) was fed to the fingerlings (6.61 ± 0.06 g) of silver barb ( Puntius gonionotus ) for 120 days in triplicate fertilized ponds (0.04 ha) with a stocking density of 9000 fish ha⁻¹. Fish were fed at 10% of their body weight for the first month, followed by 3% in the second and 2.5% in the third and fourth months of the culture period. The fish fed diets D-1, D-2 and D-3 grew from initial weights of 6.67, 6.67 and 6.50 g to 320.23, 298.23 and 305.13 g respectively. No significant variation ( P >0.05) was found in the growth and nutrient utilization of fish fed different dietary treatments. Net profits of Indian Rupees 67 385, 59 535 and 65 790 ha⁻¹ were obtained in fish fed D-1, D-2 and D-3, respectively, within 120 days of culture. The results of this study suggest the possibility of the use of mustard oil cake as a dietary protein source for pond culture of silver barb in addition to groundnut and soybean oil cakes without compromising the growth, nutrient utilization, production performance and economics of culture of this fish.     

In vitro germination and viability of buckwheat (Fagopyrum esculentum Moench) pollen

An in vitro method for the germination of common buckwheat pollen was developed. Pollen grains were successfully germinated in an artificial medium consisting of 0.2 g each of MnSO₄, Ca(NO₃)2.4H₂O and KNO₃, 0.04 g H₃BO₃, 15 g sucrose and 30 g polyethylene glycol (molecular weight approximately 20,000) dissolved in 100 ml of double distilled water. The viability of pollen was assessed by in vivo and in vitro germination tests at 20 °C and 25 °C over a 38 h time period. Pollen grains were collected and germinated at 4 h intervals from freshly harvested flowers grown under 16 h day length and a constant temperature. Maximum pollen viability was found 2 h and 6 h after first light when plants were maintained at 25 °C and 20 °C, respectively. Viability, as measured by germination percentage, was similar at both temperature regimes. Some pollen remained viable for approximately 34 to 38 h in intact flowers, but all pollen lost viability in less than an hour when stored at room temperature without humidity control. This revised version was published online in July 2006 with corrections to the Cover Date.     

Genotypic and Pathotypic Diversity in Xanthomonas oryzae pv. oryzae in Nepal

ABSTRACT Among the 171 strains of Xanthomonas oryzae pv. oryzae (the bacterial blight pathogen of rice) collected from eight rice-producing zones in Nepal, 31 molecular haplotypes were distinguished using two polymerase chain reaction-based assays. Six common haplotypes represented nearly 63% of the strains, and some haplotypes were geographically dispersed. Multiple correspondence analysis divided the collection into five putative genetic lineages. Lineages 1, 2, and 4 were the most frequently detected and occurred in diverse geographic populations. Twenty-six pathotypes (virulence phenotypes) of X. oryzae pv. oryzae were identified using 11 near-iso-genic rice lines, each containing a single gene for resistance. The 26 pathotypes grouped into five clusters, and cluster 1 contained wide virulence spectrum strains from all geographic populations. Although molecular variation was greatest between strains of different virulence phenotypes, some variation was observed among strains with identical virulence. There was a weak correlation (r = 0.52) between molecular haplotypes and virulence phenotypes. There are two major groups of X. oryzae pv. oryzae in Nepal. One group consists of strains with high molecular polymorphism and many pathotypes that are either virulent to the 11 major resistance genes or avirulent only to Xa21. Strains in the second group have low molecular polymorphism and are avirulent to Xa4, xa5, Xa7, and Xa21.     

Energy-Dispersive X-ray Fluorescence Spectrometry for Cost-Effective and Rapid Screening of Pearl Millet Germplasm and Breeding Lines for Grain Iron and Zinc Density

Comparison of energy-dispersive X-ray fluorescence (XRF) and inductively coupled plasma-optical emission spectroscopy (ICP) for iron (Fe) and zinc (Zn) densities in pearl millet grain samples from 11 trials showed significant differences between these two methods for both micronutrients. XRF values were more often higher than the ICP values for both micronutrients, but the differences were significant in only 15–38% genotypes for Fe and in 7–25% genotypes for Zn across the trials. In 82% genotypes the differences between these two methods were ≤6 mg kg^?1 for Fe; and in 88% genotypes, the differences were ≤4 mg kg^?1for Zn. There were highly significant and high positive correlations between ICP and XRF for both micronutrients. Selection of genotypes above the XRF trial mean for Fe/Zn included at least 30% top-ranking genotypes based on ICP. Therefore, XRF can be used for cost-effective and rapid screening of a large number of grain samples in pearl millet biofortification programs.     

From sharecropping to crop-rent: women farmers changing agricultural production relations in rural South Asia

This paper explores changing production relations in agriculture in context of increasingly widespread and longer-duration male outmigration, as against previous, short-duration and seasonal migration. It investigates how de facto women-heads of households (WHHs) are changing a resilient crop-sharing system in absence of adequate access to productive assets, formal training or experience in farming, and while contributing labour to farming and coping with gendered demands on their time. Based on qualitative inquiry in one of the poorest parts of South Asia, the Eastern Gangetic Plains, the paper shows that a section of WHHs are replacing sharecropping arrangements with fixed-value rental arrangements that resemble commercial contracts. The paper ends with a discussion on the implications of this emerging development.     

Regeneration ecology and population status of a critically endangered and endemic tree species （Ilex khasiana Purk.） in north-eastern India

Detailed studies on population structure and regeneration ecology of Ilex khasiana were carried out at five representative natural populations i.e. Mylliem (Population - I), Upper Shillong (Population - II), Shillong Peak (Population - III), Laitkor (Population - IV) and Nongpiyur (Population - V) to probe into the responsible affecting factors for its population structure and regeneration ability in these populations. Experimental observation under three controlled light conditions (full sunlight (100%), intermediate sunlight (50%) and low sunlight (30%)) showed that the growth status and survival rates of seedlings under intermediate and low light were better than those under the high light condition. The density-diameter distribution in population of adult trees (≥5cm dbh) exhibited a typical character of a regenerating population. A higher seedling mortality rate in natural populations of I. khasiana was most probably due to increase in light intensity following vegetation destruction and other anthropogenic disturbances that cause opening of forest canopy. The findings of the present study would be of immense value in formulating appropriate conservation measures for the species.     

Acquired tolerance of tomato fruits to sunscald

The effect of various conditions on tolerance of tomato fruits to sunscald injury was studied. Tolerance was acquired either during a developmental period in the field or during a short period of exposure to sub-damage temperature of sensitive detached fruits. Heat treatment, rather than light, was found to be the factor influencing the development of tolerance. Saturating the fruits with water increased their sensitivity to sunscald injury.     

Cost-Benefit Analysis of a Community Forest in Nepal

Community forestry is an approach for mitigating deforestation and forest degradation by managing the forest resources for benefitting neighboring communities. Monetary benefits and costs are associated in a community forest during conservation and management of a forest. For sustainable forest management, the benefit should be more than cost which is a contesting issue of research. So, this study was conducted in a community forest of the central part of Nepal with the help of 80 household surveys and a focus group discussion. The firsthand information collected at the site is complimented by forest product harvest and cost-related secondary information. It was observed that the total annual harvest of timber was 60 cubic feet, pole was 8 cubic feet, firewood was 1,110 Bhari,¹ fodder was 4,388 Bhari, and leaf litter was 590 Bhari. To manage a forest, people were involved in fencing, thinning, and meetings. Management cost was six times higher than administration cost. The benefit from firewood and fodder was more due to the dependency of people in a forest for enhancing their livelihood. The higher value of benefit cost ratio indicates that the Community Forest User Group benefited from community forest management.