Quantifying the Impact of Climatic Change on Yields and Yield Variability of Major Crops and Optimal Land Allocation for Maximizing Food Production in Different Agro-Climatic Zones of Tamil Nadu, India: An Econometric Approach

本研究では、気候変動下での最適土地利用計画のフレームワークを提供する。気候変動が農業生産へ与える影響は多方面にわたる。すべての農業生産活動は非常に気候変動に対して敏感であり、作物収量の変動を伴う。よって、気候変動の影響を平均収量のみではなく、変動について研究することが必要である。定量的な情報は自然資源の賢明な利用と土地配分の最適化のために利用されるべきである。回帰分析を使った過去の研究では、平均生産性にのみ注目し、気候変動にともなう作物生産性の競合による最適土地配分にはあまり注目していなかった。都市化によって農業用地が減少している状況では、この問題はさらに重要度を増している。本研究では、この問題をタミルナドゥ州で生産されている主要穀物について検討する。計量経済分析により、平均収量と変動収量、そして異なる作物収量の共分散を推計する。気候変動の影響を反映している推計された平均収量は、多目的線形計画モデルによって最大穀物収量、最大米収量、現在の作物生産を維持するための最小農業用地などの目的を達成するために利用される。最後に、本研究では、２０２１年と２０２６年のタミルナドゥ州の人口予測と最適食料穀物生産をリンクさせて、一人当たりの可能食料穀物量を決定する。研究の結果、降雨量と温度は生産性と穀物の変動にさまざまな影響を与え、またHADCM3A2a シナリオによる気候変動は、タミルナドゥ州の５区域での作物生産性への影響は小さかった。伝統的な稲作地区では変動の増加と共に生産性も増加した。一方、多くの他の穀物の生産性は減少し、同一的な変化はなかった。土地のみが制約である場合、気候変動による生産性の変化により、作物の最適配分により食穀物の生産は増加する。これらの結果は政策決定者にとって人口予測下での穀物の供給と需要のギャップを知るために有効である。This paper provides a framework for optimal land use planning in the context of climate change. All agricultural activities are very sensitive to climate change resulting in variability in crop yields. Hence it becomes necessary to study the effect of climate change not only on mean yield but also on variability in yield. The quantitative information so obtained should be used for optimal land allocation in order to utilize natural resources in a judicious way. Previous studies using regression techniques concentrated on the estimation of average productivity only but little attention was given for optimal land allocation to competing crops with climate change induced productivities. The problem becomes more important in the context of gradual decline in available land area for agriculture due to urbanization. The present study focuses on these issues for major crops grown in Tamil Nadu State. It employs econometric modelling for estimating the mean yield and yield variability and also covariance between yields of different crops. The mean yields so obtained which reflect the impact of climate change are then used in multi-objective linear programming models for meeting objectives like maximum food grain production, maximum paddy production and minimization of agricultural land area for maintaining at least the current level of production of crops etc. Finally the study attempts to link the optimal food grain production with the projected population of Tamil Nadu for 2021 and 2026 to determine the quantum of food grain availability per individual. The study shows that precipitation and temperature have varying effect on productivity and variability of crops. Trend has positive impact on most of the crops. Also, climate change, as dictated by HADCM3A2a scenario, will have modest impact on crop productivities across the five zones of Tamil Nadu. Zones where paddy is grown traditionally may witness modest increase in productivity followed by increase in variability while many other crops may have decrease in productivity and there is no uniformity in changes in their variability. The study indicates that when land is the only constraint, with climate change induced productivities, optimal allocation of crop area will result in increased production of food grain. These results will be useful for policy makers in finding the gap between supply and demand of food grain for projected population

An Analysis of Farmers’ Perception and Awareness towards Crop Insurance as a Tool for Risk Management in Tamil Nadu

To insulate farmers against risks in agriculture, government has launched several schemes such as National Agricultural Insurance Scheme and weather index based crop insurance schemes. But their coverage seems to be limited among the farmers primarily due to lack of full information. This paper has reported the results of a survey of 600 farmers conducted to assess their perception about various facets of crop insurance schemes. The Probit and Tobit models have been employed to analyse the factors affecting awareness among the farmers. Crop diversification index has also been used to examine the farmers’ adjustment mechanism against risks. The survey has revealed that most farmers (65%) are aware of risk mitigation measures of the government. But, only half of the farmers have been found aware about the crop insurance schemes/products. This implies that there is need to disseminate information about insurance schemes across the target groups. Further, it has been shown that factors such as gross cropped area, income from other than agricultural sources, presence of risk in farming, number of workers in the farm family, satisfaction with the premium rate and affordability of the insurance premium amount significantly and positively influence the adoption of insurance and premium paid by the farmers. The study has clearly brought out the urgency of developing more innovative products, having minimum human interventions.Crop insurance, Risk management, Crop diversification index, Agricultural and Food Policy, Q14, Q18,

インドタミルナドゥ州の最脆弱農業気候ゾーンにおける降雨量不足保険支払い

Weather based insurance is a resilience strategy adopted by farmers. It is intended to provide protection to the cultivator against declined rainfall, which is deemed to adversely affect the crop during its cultivation period. It is becoming popular nowadays in India due to high fluctuation in rainfall and other climate related parameters. The present paper provides a method to compute the initial premium for each crop based on the premium structure given by Agricultural Insurance Company of India Limited, New Delhi. For this, the duration in each stage of selected crop identified by Crop Production Guide(2005) jointly published by Tamil Nadu Agricultural University and Department of Agriculture, Government of Tamil Nadu and 30 years of rainfall data from Indian Meteorological Department (IMD) were used. The payout structure was derived for each stage of the selected crop in the respective district. The strike or upper threshold of the rainfall corresponds to the 30 year average accumulated rainfall of the district reference weather station while the exit or lower threshold is intended to equal the water requirement of the respective crop necessary to avoid complete crop failure. This way, the weather based crop insurance acts as a resilience mechanism for rainfall uncertainties.和文のものは、英文の報告の内容を要約したものとなってい

タミルナドゥ州沿岸郡における農業の多角化―時空的分析

Crop diversification is considered as a resilience mechanism followed by farmers in different regions. Socio-ecological systems of coastal areas are more vulnerable to the impact of climatic changes. In the present paper, it is shown that there exists wide spatio-temporal disparity in the diversification of crops in the coastal districts of Tamil Nadu State, India. This is done by constructing a crop diversification index which provides a basis for ranking the different districts. So in those regions which are more vulnerable for climatic change, more diversification of crops must be attempted to avoid risk of crop failure and loss of income and employment to the rural people.和文のものは、英文の報告の内容を要約したものとなってい

Current-Current Deformations of Conformal Field Theories, and WZW Models

Moduli spaces of conformal field theories corresponding to current-current deformations are discussed. For WZW models, CFT and sigma model considerations are compared. It is shown that current-current deformed WZW models have WZW-like sigma model descriptions with non-bi-invariant metrics, additional B-fields and a non-trivial dilaton.Comment: 30 pages, latex, v2: remarks and references adde

Initial acquisition and succession of the cystic fibrosis lung microbiome is associated with disease progression in infants and preschool children

The cystic fibrosis (CF) lung microbiome has been studied in children and adults; however, little is known about its relationship to early disease progression. To better understand the relationship between the lung microbiome and early respiratory disease, we characterized the lower airways microbiome using bronchoalveolar lavage (BAL) samples obtained from clinically stable CF infants and preschoolers who underwent bronchoscopy and chest computed tomography (CT). Cross-sectional samples suggested a progression of the lower airways microbiome with age, beginning with relatively sterile airways in infancy. By age two, bacterial sequences typically associated with the oral cavity dominated lower airways samples in many CF subjects. The presence of an oral-like lower airways microbiome correlated with a significant increase in bacterial density and inflammation. These early changes occurred in many patients, despite the use of antibiotic prophylaxis in our cohort during the first two years of life. The majority of CF subjects older than four harbored a pathogen dominated airway microbiome, which was associated with a further increase in inflammation and the onset of structural lung disease, despite a negligible increase in bacterial density compared to younger patients with an oral-like airway microbiome. Our findings suggest that changes within the CF lower airways microbiome occur during the first years of life and that distinct microbial signatures are associated with the progression of early CF lung disease

Sialic acid-to-urea ratio as a measure of airway surface hydration

Although airway mucus dehydration is key to pathophysiology of cystic fibrosis (CF) and other airways diseases, measuring mucus hydration is challenging. We explored a robust method to estimate mucus hydration using sialic acid as a marker for mucin content. Terminal sialic acid residues from mucins were cleaved by acid hydrolysis from airway samples, and concentrations of sialic acid, urea, and other biomarkers were analyzed by mass spectrometry. In mucins purified from human airway epithelial (HAE), sialic acid concentrations after acid hydrolysis correlated with mucin concentrations (r2 = 0.92). Sialic acid-to-urea ratios measured from filters applied to the apical surface of cultured HAE correlated to percent solids and were elevated in samples from CF HAEs relative to controls (2.2 ± 1.1 vs. 0.93 ± 1.8, P < 0.01). Sialic acid-to-urea ratios were elevated in bronchoalveolar lavage fluid (BALF) from β-epithelial sodium channel (ENaC) transgenic mice, known to have reduced mucus hydration, and mice sensitized to house dust mite allergen. In a translational application, elevated sialic acid-to-urea ratios were measured in BALF from young children with CF who had airway infection relative to those who did not (5.5 ± 3.7 vs. 1.9 ± 1.4, P < 0.02) and could be assessed simultaneously with established biomarkers of inflammation. The sialic acid-to-urea ratio performed similarly to percent solids, the gold standard measure of mucus hydration. The method proved robust and has potential to serve as flexible techniques to assess mucin hydration, particularly in samples like BALF in which established methods such as percent solids cannot be utilized

Official American thoracic society clinical practice guidelines: Diagnostic evaluation of infants with recurrent or persistent wheezing

Background: Infantile wheezing is a common problem, but there are no guidelines for the evaluation of infants with recurrent or persistent wheezing that is not relieved or prevented by standard therapies. Methods: An American Thoracic Society-sanctioned guideline development committee selected clinical questions related to uncertainties or controversies in the diagnostic evaluation of wheezing infants. Members of the committee conducted pragmatic evidence syntheses, which followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. The evidence syntheses were used to inform the formulation and grading of recommendations. Results: The pragmatic evidence syntheses identified few studies that addressed the clinical questions. The studies that were identified constituted very low-quality evidence, consisting almost exclusively of case series with risk of selection bias, indirect patient populations, and imprecise estimates. The committee made conditional recommendations to perform bronchoscopic airway survey, bronchoalveolarlavage,esophagealpHmonitoring,andaswallowing study.Italsomadeconditionalrecommendationsagainstempiricfood avoidance, upper gastrointestinal radiography, and gastrointestinal scintigraphy. Finally, the committee recommended additional research about the roles ofinfantpulmonaryfunction testingand food avoidance or dietary changes, based on allergy testing. Conclusions: Although infantile wheezing is common, there is a paucity of evidence to guide clinicians in selecting diagnostic tests for recurrent or persistent wheezing. Our committee made several conditional recommendations to guide clinicians; however, additional research that measures clinical outcomes is needed to improve our confidence in the effects of various diagnostic interventions and to allow advice to be provided with greater confidence

Mucus accumulation in the lungs precedes structural changes and infection in children with cystic fibrosis

Although destructive airway disease is evident in young children with cystic fibrosis (CF), little is known about the nature of the early CF lung environment triggering the disease. To elucidate early CF pulmonary pathophysiology, we performed mucus, inflammation, metabolomic, and microbiome analyses on bronchoalveolar lavage fluid (BALF) from 46 preschool children with CF enrolled in the Australian Respiratory Early Surveillance Team for Cystic Fibrosis (AREST CF) program and 16 non-CF disease controls. Total airway mucins were elevated in CF compared to non-CF BALF irrespective of infection, and higher densities of mucus flakes containing mucin 5B and mucin 5AC were observed in samples from CF patients. Total mucins and mucus flakes correlated with inflammation, hypoxia, and oxidative stress. Many CF BALFs appeared sterile by culture and molecular analyses, whereas other samples exhibiting bacterial taxa associated with the oral cavity. Children without computed tomography–defined structural lung disease exhibited elevated BALF mucus flakes and neutrophils, but little/no bacterial infection. Although CF mucus flakes appeared “permanent” because they did not dissolve in dilute BALF matrix, they could be solubi-lized by a previously unidentified reducing agent (P2062), but not N-acetylcysteine or deoxyribonuclease. These findings indicate that early CF lung disease is characterized by an increased mucus burden and inflammatory markers without infection or structural lung disease and suggest that mucolytic and anti-inflammatory agents should be explored as preventive therapy