Yield Growth Rate Research Articles

Geochemical evidence of Milankovitch cycles in Atlantic Ocean ferromanganese crusts

Hydrogenetic ferromanganese crusts are considered a faithful record of the isotopic composition of seawater influenced by weathering processes of continental masses. Given their ubiquitous presence in all oceans of the planet at depths of 400–7000 meters, they form one of the most well-distributed and accessible records of water-mass mixing and climate. However, their slow accumulation rate and poor age constraints have to date limited their use to explore 100 ka paleoclimatic phenomena. Here it is shown how the Pb isotope signature and major element content of a Fe-Mn crust from the north-east Atlantic responded to changes in the intensity and geographic extent of monsoonal rainfall over West Africa, as controlled by climatic precession during the Paleocene. The studied high-spatial resolution (4 μm) laser-ablation multi-collector inductively coupled plasma mass spectrometer (LA-MC-ICP-MS) Pb isotope data is a nearly 2 order of magnitude improvement in spatial and temporal resolution compared to micro-drill subsamples. The record demonstrates cyclicity of the 206Pb/204Pb and 208, 207Pb/206Pb ratios at the scale of single Fe-Mn oxide laminae, in conjunction with variations in the Fe/Mn ratio, Al, Si and Ti content. Time-frequency analysis and astronomical tuning of the Pb isotope data demonstrates the imprint of climatic precession (∼20 ka) modulated by eccentricity (∼100 and 405 ka), yielding growth rates of 1.5–3.5 mm/Ma consistent with previous chemostratigraphic age models. In this context, boreal summer at the perihelion causes stronger insolation over West Africa, resulting in more intense and geographically extended monsoonal rainfalls compared to aphelion boreal summer conditions. This, in turn, influences the balance between the weathering endmembers feeding the north-east Atlantic basin. These results provide a new approach for calibrating Fe-Mn crust records to astronomical solutions, and allow their isotopic and chemical archive to be exploited with an improved temporal resolution of 1000–5000 years.

Insights into growth kinetics and roles of enzymes of Krebs' cycle and sulfur oxidation during exochemolithoheterotrophic growth of Achromobacter aegrifaciens NCCB 38021 on succinate with thiosulfate as the auxiliary electron donor.

Achromobacter aegrifaciens NCCB 38021 was grown heterotrophically on succinate versus exochemolithoheterotrophically on succinate with thiosulfate as auxiliary electron donor. In batch culture, no significant differences in specific molar growth yield or specific growth rate were found for the two growth conditions, but in continuous culture in the succinate-limited chemostat, the maximum specific growth yield coefficient increased by 23.3% with thiosulfate present, consistent with previous studies of endo- and exochemolithoheterotrophs and thermodynamic predictions. Thiosulfate oxidation was coupled to respiration at cytochrome c551, and thiosulfate-dependent ATP biosynthesis occurred. Specific activities of cytochrome c-linked thiosulfate dehydrogenase (E.C. 1.8.2.2) and two other enzymes of sulfur metabolism were significantly higher in exochemolithoheterotrophically grown cell extracts, while those of succinyl-transferring 2-oxoglutarate dehydrogenase (E.C. 1.2.4.2), fumarate hydratase (E.C. 4.2.1.2) and malate dehydrogenase (NAD+, E.C. 1.1.1.37) were significantly lower-presumably owing to less need to generate reducing equivalents during Krebs' cycle, since they could be produced from thiosulfate oxidation.

Effect of calibration height on the performance of mobile application for the leaf area estimation

Rice and wheat are the staple source of nourishment of billions of Indians. India is the second largest producer of rice and wheat after China, indicating the role of both the crop in food security of the nation. Both the crops played key role in transforming the nation from a food deficient nation to a food sufficient nation. The present study examines the growth and instability in in wheat area, production and productivity these two eminent crops over a period of 1950-51 to 2015-16 and also the study tries to decompose the major factors contributing to growth of production in India. The study revealed that throughout the whole period, there is positive significant growth rate in area, production and yield. The analysis over the sub periods showed variations in rate of growth. The analysis of instability showed that in both rice and wheat production recorded more variation as compared to area and productivity. Decomposition analysis showed that yield effect contributed more to rice production, whereas in wheat interaction effect was more dominant factor.

Growth and Instability Analysis of India’s Food Grain Sector in the Post Liberalisation Period

Background: Having a population growing at an annual average rate of 1.2 per cent and more than half of its total size depend on primary sector for their livelihood, agricultural sector occupy significant role in the economy of India. The extent of area, production and productivity of food grains and their instability therefore attracts special attention. The present study thus analyses the performance of agricultural sector in India in terms of trend in growth and instability of area, production and productivity of food grain during the three decades of liberalisation. The specific objectives are (i) to examine the growth rate and instability in area, production and yield of food grains in India and (ii) to explain the decomposing changes in the variability of food grains production in India. Methods: In this field-laboratory investigation during 1990-91 to 2018-19, official secondary data has been utilized. Statistical tools like Least Square Growth Rate, Coefficient of Variation of area, production, and yield etc. have been applied for analysis. Result: The study highlighted that area under food grain cultivation remained almost stagnant. However, the overall food grain production registered growth rate of 2 per cent while the production instability was 15.88 per cent. The trend lines fitted to the production of foodgrains shows positive growth rate. The co-efficient of determination (R2) shows 87 percent for production and 92 percent for productivity which determines scope for further production for India. But in area it shows just 3.9 per cent. The result of the study shows that the production of food grains has increased with due instability during given the time period. It also calls for adopting alternate production technologies which will further improve the productivity of food grains to meet increasing demand from the growing population.

Metoclopramide induces preparturient, low-level hyperprolactinemia to increase milk production in primiparous sows

Inadequate milk production by sows often limits the growth of piglets. A successful lactation requires prolactin (PRL)-induced differentiation of the alveolar epithelium within the mammary glands of sows between days 90–110 of gestation. We hypothesized that induction of late gestational hyperprolactinemia in primiparous sows by oral administration of the dopamine antagonist metoclopramide (MET) would enhance mammary epithelial differentiation, milk yield, and piglet growth rate and that these effects would carry over into a subsequent lactation. Twenty-six gilts were assigned to receive either MET (n = 13, 0.8 mg/kg) or vehicle (CON, n = 13) twice daily from days 90–110 of gestation. The same sows were followed into their second lactation without additional treatment. On day 90 of gestation, circulating PRL concentrations peaked 45 min after feeding MET (P < 0.001) and then returned to baseline 3 h later. This response occurred daily out to day 104 of gestation (P < 0.05). Compared with CON, MET-treated gilts had enlarged alveoli on gestation day 110 (P < 0.05). Treatment with MET did not affect feed intake, body weight, or body fatness during pregnancy or lactation. Piglets born to MET-treated sows had both increased body weights and average daily gain on lactation days 14 and 21 (P < 0.05). Milk intake by piglets was estimated from deuterium oxide dilution. Although milk intake by piglets nursing MET sows was not statistically different from those nursing CON sows on day 21 of lactation (P = 0.18), there was a greater increase in milk consumption by piglets born to MET-treated sows between days 9 and 21 of lactation than for those in CON litters (P < 0.001). In one group of second parity sows (n = 11) that were treated with MET during their first gestation, milk yield increased by 21% during their second lactation (P < 0.05) in association with a 14% decline in body fatness across lactation compared with a 7% decline in CON sows (P < 0.05). These findings demonstrate that MET-induced hyperprolactinemia in primiparous sows during late pregnancy can increase milk yield and piglet growth rate, setting the stage for further large-scale studies.

Yield components in new pear cultivars and breeding forms in the Middle Urals

Sverdlovsk Horticultural Breeding Station specializes in the development of fruit and berry cultivars for the Middle Urals. One of its tasks is pear breeding for high winter-hardiness, high yield, and good fruit quality. Ten new pear cultivars and improved forms of local breeding were selected as the material for this study versus the reference cultivars ‘Talitsa’, ripening in summer, and ‘Berezhenaya’, ripening in late autumn. Observations were conducted across the decade of 2009–2019. The cultivars ‘Letnyaya zolotistaya’, ‘Chusovaya’, ‘Berezhenaya’ (ref.), ‘Sultan’, and breeding form DL-33-307 were found to possess resistance of flowers to late spring frosts. Cvs. ‘Letnyaya zolotistaya’, ‘Berezhenaya’ (ref.) and ‘Sultan’ were early-fruiting; cvs. ‘Talitsa’ (ref.) and ‘Chusovaya’, breeding forms ZS-IV-5-11, DL-33-307, DL-II-31n-207, ZS-II-15-18 and ZS-IV-5-19 were mid-fruiting; breeding form ZS-IV-15-38, late-fruiting. An early onset of full fructification at the age of 10–11 years or more, combined with high yield at the same age, was observed in cvs. ‘Berezhenaya’ (ref.), ‘Sultan’, ‘Letnyaya zolotistaya’, and breeding form ZS-II-15-18. New cultivars ‘Letnyaya zolotistaya’ and ‘Sultan’ were highlighted for a combination of valuable traits: earliness, high yield, and high growth rates in the plantlet stage. Cv. ‘Letnyaya zolotistaya’ had attractive good-tasting fruits, weighing 76 g, ripening in summer. Cv. ‘Sultan’ yielded nicelooking and good-tasting fruits, weighing 129 g, ripening in winter. Cv. ‘Chusovaya’ was identified for its nice-looking fruits with a very good taste.

Growth, Instability and Decomposition Analysis of Coconut in India and Tamil Nadu, Western Tamil Nadu, India: A Time Series Comparative Approach

The study was undertaken to know the growth rate, instability, and contribution of area and yield on the production of coconut. The study was based on the secondary data for the period of 19 years (2001 – 2019) for India as well as Tamil Nadu. India is the leading producer of coconut globally 21.38 billion nuts and in the country, Tamil Nadu has the major share in area and production with 5.31 billion nuts. The pace of agricultural development of the country can be estimated through compound annual growth rate, instability is measured using Coppocks instability index and contribution of area and yield on production is studied using decomposition analysis. Results revealed that coconut growth is found to be positive in India as well as in Tamil Nadu, the production of coconut in the country is significantly positive (0.74 percent), but in the state, it is in decline trend (2.48 percent). The trend of productivity seems positive and similar at both the country and state level. Instability index is higher in terms of area (12.71 percent) than production (2.86 percent) and productivity (2.89 percent). Area effect was most responsible (138.2 percent and 98.3 percent) for the production of coconut than yield effect in both the country as well as the state.

Viscous Rayleigh-Taylor and Richtmyer-Meshkov instabilities in the presence of a horizontal magnetic field.

We first derive the exact dispersion relation for viscous Rayleigh-Taylor instability in the presence of a horizontal magnetic field using a decomposition method, and we find that the horizontal magnetic field contributes to the generation of vorticity inside the flow, thereby further distorting the velocity field. This differs from the previous view of the horizontal magnetic field behaving as a surface-tension-like force that does not produce any vorticity in inviscid flow. Vorticity transport is also investigated. The well-known approximate dispersion relation yields growth rates based on an irrotational approximation with a maximum error of 19% in comparison with the exact rates. Furthermore, we investigate the physics of the viscous Richtmyer-Meshkov instability in the presence of a magnetic field, and we find that the presence of the magnetic field leads to the generation of more eigenvalues, thereby modifying the motion of the interface. Comparisons confirm that the viscosity and magnetic field both play fundamental roles in interface behavior, and it is clarified that the behaviors of the interface for viscous Richtmyer-Meshkov instability become in agreement with the numerical simulations. The dependences of the eigenvalues on the viscosities and densities of the fluids, as well as on the magnetic field, are also discussed. Finally, we analyze the evolution of the decay modes to investigate the rotationality of the velocity fields.

СОВЕРШЕНСТВОВАНИЕ ГОСУДАРСТВЕННОЙ ПОДДЕРЖКИ РАЗВИТИЯ МОЛОЧНОГО СКОТОВОДСТВА

The problem of improving state support for enterprises of the dairy product complex, in particular dairy cattle breeding, remains relevant. Its solution will contribute to the preservation of livestock and increase milk production. The current system of state support for agricultural producers in Ulyanovsk region in the form of subsidies for sold milk is inefficient, and only organizations that ensure an increase in milk yield, as well as maintaining milk production and calf output per 100 cows, can receive it. In addition, the amount of subsidy per 1 liter of milk sold is only 0.54 rubles. This does not stimulate the development of dairy cattle breeding in the region, as evidenced by the low growth rate of gross milk yield for 2014–2018. The sector’s efficiency in agricultural enterprises - the main producers of marketed milk - decreased by 6.0 percentage points, amounting to 21.9% in 2018. The purpose of the study is to develop proposals for improving state support for dairy cattle breeding in the Ulyanovsk region. In general, it should be aimed at preserving (increasing) the number of dairy herds and maintaining the productivity of cows not lower than the average regional value. The amount of the proposed subsidies under the state support program for dairy cattle breeding in the region may amount to 12.0 thousand rubles. per 1 cow, including 2.0 thousand rubles for the safety of the livestock, 10.0 thousand rubles - for the productivity of cows. With this approach, in 2018, 52.5 million rubles would have been required for state support for the development of the dairy cattle industry in agricultural enterprises in the region, the subsidy per 1 liter of milk sold would have amounted to 1.66 rubles

Efecto de bacterias PGPB, composta y digestato en el rendimiento de materia seca de pasto ovillo

El objetivo fue determinar el efecto de composta, digestato y bacterias plant growth-promoting bacteria (PGPB) en la curva de crecimiento, acumulación de biomasa, tasa de crecimiento, altura de planta y unidades soil plant analysis development (SPAD) en pasto ovillo recién establecido, bajo condiciones de invernadero. Los tratamientos fueron: digestato (60%), composta (10% en base seca del suelo), bacterias: Brevibacterium frigoritolerans, Bacillus simplex, Pseudomonas putida, control positivo (fertilización con triple 17) y el control negativo (suelo sin fertilización). Se utilizó un diseño experimental completamente al azar, la unidad experimental fue una maceta con diez tallos de pasto ovillo, con cuatro repeticiones por tratamiento. Los valores más altos (p&lt; 0.05) de materia seca (6.4 g MS maceta), tasa de crecimiento (0.15 g MS maceta d-1) y altura de forraje (18.3 cm) se registraron en el tratamiento con composta; donde el rendimiento final de materia seca superó 200% al testigo negativo. El tratamiento con digestato evidenció valores inferiores a los obtenidos con composta, pero superó al resto de los tratamientos. Las mejores bacterias PGPB fueron Pseudomonas putida y Bacillus simplex que superaron el rendimiento de materia seca 25 y 37% con respecto a Brevibacterium frigoritolerans y al control negativo, respectivamente. Las bacterias PGPB pueden ser una alternativa de fertilización ya que el rendimiento de materia seca fue mayor que con el control negativo y se igualó al rendimiento obtenido con fertilización química; sin embargo, los dos fertilizantes orgánicos (composta y digestato) favorecieron el mayor rendimiento de materia seca.

Genetic Improvement Strategy of Indigenous Cattle Breeds: Effect of Cattle Crossbreeding Program in Production Performances

The aim of the review is to summarize the fragmented production performance information on the effects of cattle crossbreeding in different parts of the globe. Most studies indicated that cattle crossbreeding practices conducted under extensive management system for small scale dairy farms is attractive because the optimum requirement (50-62.5%) of exotic cattle blood level inheritance was maintained. However, most developing countries do not use systematic crossbreeding programme. For example, dairy cattle crossbreeding programme in Ethiopia lacks clear breeding policy regarding the breed type to be used and the level of exotic blood inheritance across different agro-ecology and production system. Heterosis is an essential advantage of crossbreeding and maximum heterosis is realized in the first cross (F1) of distinctly different breeds. The purpose of crossbreeding in beef cattle is partly to combine breed differences and partly to make use of heterosis to improve production. Heterosis is highest in F1 generation compared to F2, F3 and F4 crossbred generations. Therefore, terminal crossbreeding is very important in livestock production particularly in beef production. Holstein Friesian dairy cattle produce 40-60% lowered milk yield under tropical and subtropical conditions compared to temperate conditions, and this is due to the exposure of the animals to the different stress factors in the tropical and subtropical conditions. The review also revealed that crossbreeding programme has significant effect in birth weight because all F1 crossbred calves have highest birth weight compared to the purebred calves of Zebu, Sanga and Zenga breeds. Heterosis in a sound crossbreeding program could increase productivity in the beef cow herd by as much as 26% over a comparable straight breeding program. In general, crossbreeding in tropical countries is undertaken to combine superior hardiness, heat tolerance, disease tolerance and/or resistance and environmental adaptability of indigenous cattle with superior milk yield and faster growth rates of exotic temperate breeds. Crossbreeding is one tool to minimize the negative impacts of inbreeding depression in livestock sector. Through crossbreeding there is a chance to have highly productive and adapted breeds. Crossbreeding also affects milk fat and protein compositions of purebred cattle. However, if crossbreeding is indiscriminate and uncontrolled, it may result in poor production performance. Furthermore, a number of studies indicated that indiscriminate and uncontrolled crossbreeding is a major threat to sustainable conservation and utilization of indigenous cattle breeds. Therefore, crossbreeding must be introduced in controlled farms.

Interactive effects of roxithromycin and freshwater microalgae, Chlorella pyrenoidosa: Toxicity and removal mechanism

Roxithromycin (ROX) has received increasing concern due to its large usage, ubiquitous detection in environment and high ecotoxicology risk. This study investigated the acute and chronic effects of ROX on the growth, chlorophyll, antioxidant enzymes, and malonaldehyde (MDA) content of Chlorella pyrenoidosa, as well as the removal mechanism of ROX during microalgae cultivation. The calculated 96h median effective concentration of ROX on yield (EyC50) and specific growth rate (ErC50) of C. pyrenoidosa was 0.81 and 2.87mg/L, respectively. After 96h exposure, 1.0 ~ 2.0mg/L of ROX significantly inhibited the synthesis of chlorophyll and promoted the activities of SOD and CAT (p<0.05). The MDA content increased with the ROX concentration increasing from 0.5 ~ 1.0mg/L, and then decreased to 105.76% of the control exposure to 2.0mg/L ROX, demonstrating the oxidative damage could be moderated by the upregulation of SOD and CAT activities. During the 21d chronic exposure, low concentration of ROX (0.1 and 0.25mg/L) showed no significant effect on the growth and chlorophyll content of algae during the first 14d, but significantly inhibited the growth of algae and the synthesis of chlorophyll at 21d (p<0.05 or p<0.01). 1.0mg/L ROX significantly inhibited the growth of microalgae during 3 ~ 21d and the synthesis of chlorophyll at 7 ~ 21d. High concentration and long-term exposure of low concentration of ROX caused the SOD and CAT activities and MDA content to increase, demonstrating a higher level of oxidative damage of microalgae. During the first 14d, abiotic removal of ROX played a more important role, contributing about 12.21% ~ 21.37% of ROX removal. After 14d, the biodegradation of ROX by C. pyrenoidosa gradually became a more important removal mechanism, contributing about 45.99% ~ 53.30% of ROX removal at 21d. Bio-adsorption and bioaccumulation both played minor roles in the removal of ROX during algae cultivation.

Moving toward Rice Self-Sufficiency in Sub-Saharan Africa by 2030: Lessons Learnt from 10 Years of the Coalition for African Rice Development

The Coalition for African Rice Development (CARD) was initiated as policy framework with the aim of doubling rice production in sub-Saharan Africa (SSA) over the period from 2008 to 2018. This paper assesses the contribution of the CARD policy to rice production and forecasts the local rice supply and demand for a better understanding of the policies needed to attain rice self-sufficiency by 2030. A combination of the autoregressive integrated moving average method and counterfactual approach was adopted using rice statistical data from 23 countries in SSA. Results showed that the contribution of CARD to paddy rice production in 2018 was 10.2 million ton, equivalent to 74% of target. This resulted from the increasing of area and yield by 23% and 19%, respectively. However, yield growth rate was not sustainable in almost two-third of countries. Investments on supply-push factors such as fertilizer and irrigation development, which was the focus in the past, have less effect on the rice production. We conclude that sustainable investments on demand-pull factors such as private-led modern milling sector and contract farming development should be prioritized for achieving rice self-sufficiency in SSA.

Evaluation of the status and risk of overexploitation of the Pacific billfish stocks considering non-stationary population processes

Fish population processes could exhibit non-stationary behaviour as a stochastic biological process with temporal autocorrelation that may be influenced by environmental changes. Here we developed a Bayesian autoregressive state-space surplus production modelling framework to explore potential non-stationarity in population processes. We then evaluated the consequence of non-stationary population processes on the future risk of overexploitation for three Pacific billfish stocks (striped marlin, Kajikia audax; blue marlin, Makaira nigricans; and swordfish Xiphias gladius) that are formally assessed on a regular basis by a Regional Fisheries Management Organization in the Pacific Ocean. The results showed evidence of non-stationary population processes for Western and Central North Pacific Ocean (WCNPO) striped marlin, and to a lesser extent, Pacific blue marlin and WCNPO swordfish. Trends in the theoretical maximum sustainable yield and intrinsic growth rate were observed as oscillating regimes for swordfish, and as long-term directional changes for striped marlin. The non-stationary population processes did not strongly influence the forecasted biomass trend at the current catch level for any of the three stocks. However, the future risk of overexploitation (Prob[B < BMSY]) was sensitive to changes in the population processes for striped marlin (increased the risk by 20%). This work illustrates that the inclusion of non-stationary population processes could impose challenges for developing a stock rebuilding plan and provides a framework to account for non-stationary population processes for the billfish stocks in the Pacific Ocean.

Long-run trend in agricultural yield and climatic factors in Europe

Reliable projections of crop production are an essential tool for the design of feasible policy plans to tackle food security and land allocation, and an accurate characterization of the long-run trend in crop yield is the key ingredient in such projections. We provide several contributions adding to our current understanding of the impact of climatic factors on crop yield. First of all, reflecting the complexity of agricultural systems and the time required for any change to diffuse, we show that crop yield in Europe has historically been characterized by a stochastic trend rather than the deterministic specifications normally used in the literature. Secondly, we found that, contrary to previous studies, the trend in crop yield has slowly changed across time rather than being affected by a single abrupt permanent change. Thirdly, we provide strong evidence that climatic factors have played a major role in shaping the long-run trajectory of crop yield over the decades, by influencing both the size and the statistical nature of the trend. In other words, climatic factors are important not only for the year-to-year fluctuations in crop yield but also for its path in the long-run. Finally, we find that, for most countries in this study, the trend in temperature is responsible for a reduction in the long-run growth rate of yield in wheat, whereas a small gain is produced in maize, except for Southern European countries.

Pengaruh Penyulangan Medium yang Mengandung Orange II terhadap Pertumbuhan Enterococcus faecalis ID 6017 dan Kemampuan Dekolorisasinya

The influence of fed Orange II containing medium on the growth of Enterococcus faecalis ID 6017 and its decolorization ability was studied in this research. A fed batch growth was compared with the batch growth. Total Orange II added to the both was 120 mg/L. In the fed batch, the Orange II was given into three steps. The first addition was at the initial culture medium. The second and third were added after the almost total decolorization or clearance of the Orange II given in the first or the second addition respectively. The culture was incubated under static condition and room temperature. The fed batch growth was better than the batch growth, seen from both aspects; their growth parameters and the decolorization ability. The biomass yield and specific growth rates of the fed batch was higher than the batch growth. Under fed batch growth, the decolorization was 85-94%, while the batch growth was only 54%. For achieving these performances, the fed batch growth was needed to consume more glucose.

Effects of different culture periods of commercial invasive red alga Kappaphycus alvarezii (Doty) Doty on plankton community structures in tropical marine environment, Southeast coast of India

The commercial invasive red alga Kappaphycus alvarezii was cultivated by floating raft technique for the assessment of crop yields, growth rates and their impacts on the plankton community related to hydrobiological parameters in the Munakadu coast, Southeastern India for the period of one year from February 2016 to January 2017. The ANOVA results showed that the crop yield and daily growth rate of K. alvarezii was significantly higher (p < 0.05) during the monsoon season. In the control site, a positive correlation was found between pH with NO3 and Chlorophyll-a (Chl-a) at p < 0.01 level and pH with gross primary productivity at p < 0.05 level. Gross primary productivity (GPP) was positively correlated with net primary productivity (NPP) at p < 0.01 levels. In the culture site, significant positive correlation was found between salinity and PPD; pH and GPP; DO and BOD; NO3 and C. yield; GPP and NPP. In total, 43 and 37 phytoplankton species were recorded in the control site and culture site, respectively. The overall species diversity (H’), richness (D’) and evenness (J’) of phytoplankton were higher in the control site than the culture site. Therefore, the population density of the control site seems to be higher than the culture site. The copepods and meroplankton were dominant groups that present in the highest percentages during the entire study period in the culture site. The present study suggests that copepods and meroplankton were always higher in K. alvarezii farming sites and other species were higher in the control site. The higher percentage of diatoms, cyanobacteria and the lower percentage of dinoflagellates were present in the culture sites. Evidently, the farming of K. alvarezii significantly affected the plankton population concerning different seasons in the tropical marine environment of Munaikadu coast, Southeast coast of India.

Trend and Pattern of Cereal Crops: Production, Productivity and Area Coverage in Nepal

This study conducted to examine growth trends and pattern in area, production and productivity of major cereal crops over the six fiscal years. Time series data of cereal crops coverage of annual yield were used for the study. This study was based on descriptive nature and used secondary sources of information on production, productivity and area coverage of major cereals (Paddy, Maize, Wheat, Millet, Buckwheat and Barley) covering the six fiscal years (2011/12-20116/17) data. Trends of crop's productivity were analyzed using graphical methods. Ratio and percentage were used to measure productivity (yield) growth rate of the selected crops of study. The yielding trend of cereal production is not satisfactory in Nepalese economy. Pattern of agricultural production in Nepal is affected by multiple factors including rugged topography, monsoon, insignificant investment in infrastructure, and research and development. Production and productivity would be helpful to develop the future plans and take the appropriate decisions to uphold the situation for the sustainability in food production.

Trends in Cereal Production and Yield Dynamics in Sub-Saharan Africa Between 1990-2015

Cereal serves as a very important and vital staple food for many smallholder farming communities in Sub-Saharan Africa (SSA). In this paper, we examined changes in land under cereal production; changes in cereal yield; and changes in cereal production between 1990 and 2015 in Sub-Sahara Africa (SSA). The paper looks at the threats and potential of cereal production with respects to how it helps to address issues of food security and improvements needed to enhance and promote production in the region. The study reveals that 33 (75%) of countries in SSA have experienced an expansion in land under cereal production while 11 (25%) of countries have reduced land under cereal production with an average increase of 679,664 hectares. Further, 32 (73%) of countries have experienced an increase in cereal yield, while 12 (27%) of countries have experienced a reduction in cereal yield, averaging to 311 kg per hectare in SSA. The study also shows that 35 (80%) of countries have experienced an increase in cereal production while 9 (20%) of countries have experienced a reduction in cereal production with a total of 1635201 kg per hectare in SSA. Overall, about 71% of the countries in SSA are experiencing a continuous increase in cereal production, yield levels and land area under cereal production, while about 29% are experiencing a reduction in cereal yield, production levels and land area under cereal production. However, SSA still has the lowest yield growth rate with the highest number of food-insecure persons (35.5% of its population), which is forecast to exacerbate further given the continuous population increase. Hence, it is essential to step up cereal production from the current attainable levels to an actual or reasonable and scalable level through innovative research, training, and technological advancement and production capabilities in the region.

Metabolic engineering applications of the Escherichia coli bacterial artificial chromosome

In metabolic engineering and synthetic biology, the number of genes expressed to achieve better production and pathway regulation in each strain is steadily increasing. The method of choice for expression in Escherichia coli is usually one or several multi-copy plasmids. Meanwhile, the industry standard for long-term, robust production is chromosomal integration of the desired genes. Despite recent advances, genetic manipulation of the bacterial chromosome remains more time consuming than plasmid construction. To allow screening of different metabolic engineering strategies at a level closer to industry while maintaining the molecular-biology advantages of plasmid-based expression, we have investigated the single-copy bacterial artificial chromosome (BAC) as a development tool for metabolic engineering. Using (R)-3-hydroxybutyrate as a model product, we show that BAC can outperform multi-copy plasmids in terms of yield, productivity and specific growth rate, with respective increases of 12%, 18%, and 5%. We both show that gene expression by the BAC simplifies pathway optimization and that the phenotype of pathway expression from BAC is very close to that of chromosomal expression. From these results, we conclude that the BAC can provide a simple platform for performing pathway design and optimization.