Yield gap mapping as a support tool for risk management in agriculture

NASA Astrophysics Data System (ADS)

Lahlou, Ouiam; Imani, Yasmina; Slimani, Imane; Van Wart, Justin; Yang, Haishun

2016-04-01

The increasing frequency and magnitude of droughts in Morocco and the mounting losses from extended droughts in the agricultural sector emphasized the need to develop reliable and timely tools to manage drought and to mitigate resulting catastrophic damage. In 2011, Morocco launched a cereals multi-risk insurance with drought as the most threatening and the most frequent hazard in the country. However, and in order to assess the gap and to implement the more suitable compensation, it is essential to quantify the potential yield in each area. In collaboration with the University of Nebraska-Lincoln, a study is carried out in Morocco and aims to determine the yield potentials and the yield gaps in the different agro-climatic zones of the country. It fits into the large project: Global Yield Gap and Water Productivity Atlas: http://www.yieldgap.org/. The yield gap (Yg) is the magnitude and difference between crop yield potential (Yp) or water limited yield potential (Yw) and actual yields, reached by farmers. World Food Studies (WOFOST), which is a Crop simulation mechanistic model, has been used for this purpose. Prior to simulations, reliable information about actual yields, weather data, crop management data and soil data have been collected in 7 Moroccan buffer zones considered, each, within a circle of 100 km around a weather station point, homogenously spread across the country and where cereals are widely grown. The model calibration was also carried out using WOFOST default varieties data. The map-based results represent a robust tool, not only for drought insurance organization, but for agricultural and agricultural risk management. Moreover, accurate and geospatially granular estimates of Yg and Yw will allow to focus on regions with largest unexploited yield gaps and greatest potential to close them, and consequently to improve food security in the country.

Yield potential of pigeon pea cultivars

USDA-ARS?s Scientific Manuscript database

Yield potential of twelve vegetable pigeon pea (Cajanus cajun) cultivars was evaluated at two locations in eastern Kenya during 2012 and 2013 cropping years. Pigeon pea pod numbers, seeds per pod, seed mass, grain yield and shelling percentage were quantified in three replicated plots, arranged in a...

Optimizing rice yields while minimizing yield-scaled global warming potential.

PubMed

Pittelkow, Cameron M; Adviento-Borbe, Maria A; van Kessel, Chris; Hill, James E; Linquist, Bruce A

2014-05-01

To meet growing global food demand with limited land and reduced environmental impact, agricultural greenhouse gas (GHG) emissions are increasingly evaluated with respect to crop productivity, i.e., on a yield-scaled as opposed to area basis. Here, we compiled available field data on CH4 and N2 O emissions from rice production systems to test the hypothesis that in response to fertilizer nitrogen (N) addition, yield-scaled global warming potential (GWP) will be minimized at N rates that maximize yields. Within each study, yield N surplus was calculated to estimate deficit or excess N application rates with respect to the optimal N rate (defined as the N rate at which maximum yield was achieved). Relationships between yield N surplus and GHG emissions were assessed using linear and nonlinear mixed-effects models. Results indicate that yields increased in response to increasing N surplus when moving from deficit to optimal N rates. At N rates contributing to a yield N surplus, N2 O and yield-scaled N2 O emissions increased exponentially. In contrast, CH4 emissions were not impacted by N inputs. Accordingly, yield-scaled CH4 emissions decreased with N addition. Overall, yield-scaled GWP was minimized at optimal N rates, decreasing by 21% compared to treatments without N addition. These results are unique compared to aerobic cropping systems in which N2 O emissions are the primary contributor to GWP, meaning yield-scaled GWP may not necessarily decrease for aerobic crops when yields are optimized by N fertilizer addition. Balancing gains in agricultural productivity with climate change concerns, this work supports the concept that high rice yields can be achieved with minimal yield-scaled GWP through optimal N application rates. Moreover, additional improvements in N use efficiency may further reduce yield-scaled GWP, thereby strengthening the economic and environmental sustainability of rice systems. © 2013 John Wiley & Sons Ltd.

Raising yield potential in wheat: increasing photosynthesis capacity and efficiency

USDA-ARS?s Scientific Manuscript database

Increasing wheat yields to help to ensure food security is a major challenge. Meeting this challenge requires a quantum improvement in the yield potential of wheat. Past increases in yield potential have largely resulted from improvements in harvest index not through increased biomass. Further large...

Role of Adjuvant Chemotherapy in ypT0-2N0 Patients Treated with Preoperative Chemoradiation Therapy and Radical Resection for Rectal Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, In Ja; Kim, Dae Yong; Kim, Hee Cheol

2015-07-01

Objective: To explore the role of adjuvant chemotherapy for patients with ypT0-2N0 rectal cancer treated by preoperative chemoradiation therapy (PCRT) and radical resection. Patients and Methods: A national consortium of 10 institutions was formed, and patients with ypT0-2N0 mid- and low-rectal cancer after PCRT and radical resection from 2004 to 2009 were included. Patients were categorized into 2 groups according to receipt of additional adjuvant chemotherapy: Adj CTx (+) versus Adj CTx (−). Propensity scores were calculated and used to perform matched and adjusted analyses comparing relapse-free survival (RFS) between treatment groups while controlling for potential confounding. Results: A totalmore » of 1016 patients, who met the selection criteria, were evaluated. Of these, 106 (10.4%) did not receive adjuvant chemotherapy. There was no overall improvement in 5-year RFS as a result of adjuvant chemotherapy [91.6% for Adj CTx (+) vs 87.5% for Adj CTx (−), P=.18]. There were no differences in 5-year local recurrence and distant metastasis rate between the 2 groups. In patients who show moderate, minimal, or no regression in tumor regression grade, however, possible association of adjuvant chemotherapy with RFS would be considered (hazard ratio 0.35; 95% confidence interval 0.14-0.88; P=.03). Cox regression analysis after propensity score matching failed to show that addition of adjuvant chemotherapy was associated with improved RFS (hazard ratio 0.81; 95% confidence interval 0.39-1.70; P=.58). Conclusions: Adjuvant chemotherapy seemed to not influence the RFS of patients with ypT0-2N0 rectal cancer after PCRT followed by radical resection. Thus, the addition of adjuvant chemotherapy needs to be weighed against its oncologic benefits.« less

Role of Adjuvant Chemotherapy in ypT0-2N0 Patients Treated with Preoperative Chemoradiation Therapy and Radical Resection for Rectal Cancer.

PubMed

Park, In Ja; Kim, Dae Yong; Kim, Hee Cheol; Kim, Nam Kyu; Kim, Hyeong-Rok; Kang, Sung-Bum; Choi, Gyu-Seog; Lee, Kang Young; Kim, Seon-Hahn; Oh, Seung Taek; Lim, Seok-Byung; Kim, Jin Cheon; Oh, Jae Hwan; Kim, Sun Young; Lee, Woo Yong; Lee, Jung Bok; Yu, Chang Sik

2015-07-01

To explore the role of adjuvant chemotherapy for patients with ypT0-2N0 rectal cancer treated by preoperative chemoradiation therapy (PCRT) and radical resection. A national consortium of 10 institutions was formed, and patients with ypT0-2N0 mid- and low-rectal cancer after PCRT and radical resection from 2004 to 2009 were included. Patients were categorized into 2 groups according to receipt of additional adjuvant chemotherapy: Adj CTx (+) versus Adj CTx (-). Propensity scores were calculated and used to perform matched and adjusted analyses comparing relapse-free survival (RFS) between treatment groups while controlling for potential confounding. A total of 1016 patients, who met the selection criteria, were evaluated. Of these, 106 (10.4%) did not receive adjuvant chemotherapy. There was no overall improvement in 5-year RFS as a result of adjuvant chemotherapy [91.6% for Adj CTx (+) vs 87.5% for Adj CTx (-), P=.18]. There were no differences in 5-year local recurrence and distant metastasis rate between the 2 groups. In patients who show moderate, minimal, or no regression in tumor regression grade, however, possible association of adjuvant chemotherapy with RFS would be considered (hazard ratio 0.35; 95% confidence interval 0.14-0.88; P=.03). Cox regression analysis after propensity score matching failed to show that addition of adjuvant chemotherapy was associated with improved RFS (hazard ratio 0.81; 95% confidence interval 0.39-1.70; P=.58). Adjuvant chemotherapy seemed to not influence the RFS of patients with ypT0-2N0 rectal cancer after PCRT followed by radical resection. Thus, the addition of adjuvant chemotherapy needs to be weighed against its oncologic benefits. Copyright © 2015 Elsevier Inc. All rights reserved.

Assessment of bioethanol yield by S. cerevisiae grown on oil palm residues: Monte Carlo simulation and sensitivity analysis.

PubMed

Samsudin, Mohd Dinie Muhaimin; Mat Don, Mashitah

2015-01-01

Oil palm trunk (OPT) sap was utilized for growth and bioethanol production by Saccharomycescerevisiae with addition of palm oil mill effluent (POME) as nutrients supplier. Maximum yield (YP/S) was attained at 0.464g bioethanol/g glucose presence in the OPT sap-POME-based media. However, OPT sap and POME are heterogeneous in properties and fermentation performance might change if it is repeated. Contribution of parametric uncertainty analysis on bioethanol fermentation performance was then assessed using Monte Carlo simulation (stochastic variable) to determine probability distributions due to fluctuation and variation of kinetic model parameters. Results showed that based on 100,000 samples tested, the yield (YP/S) ranged 0.423-0.501g/g. Sensitivity analysis was also done to evaluate the impact of each kinetic parameter on the fermentation performance. It is found that bioethanol fermentation highly depend on growth of the tested yeast. Copyright © 2014 Elsevier Ltd. All rights reserved.

Partitioning potential fish yields from the Great Lakes

USGS Publications Warehouse

Loftus, D.H.; Olver, C.H.; Brown, Edward H.; Colby, P.J.; Hartman, Wilbur L.; Schupp, D.H.

1987-01-01

We proposed and implemented procedures for partitioning future fish yields from the Great Lakes into taxonomic components. These projections are intended as guidelines for Great Lakes resource managers and scientists. Attainment of projected yields depends on restoration of stable fish communities containing some large piscivores that will use prey efficiently, continuation of control of the sea lamprey (Petromyzon marinus), and restoration of high-quality fish habitat. Because Great Lakes fish communities were harmonic before their collapse, we used their historic yield properties as part of the basis for projecting potential yields of rehabilitated communities. This use is qualified, however, because of possible inaccuracies in the wholly commercial yield data, the presence now of greatly expanded sport fisheries that affect yield composition and magnitude, and some possibly irreversible changes since the 1950s in the various fish communities themselves. We predict that total yields from Lakes Superior, Huron, and Ontario will be increased through rehabilitation, while those from Lakes Michigan and Erie will decline. Salmonines and coregonines will dominate future yields from the upper lakes. The Lake Erie fishery will continue to yield mostly rainbow smelt (Osmerus mordax), but the relative importance of percids, especially of walleye (Stizostedion vitreum vitreum) will increase. In Lake Ontario, yields of salmonines will be increased. Managers will have to apply the most rigorous management strictures to major predator species.

Improving carbon dioxide yields and cell efficiencies for ethanol oxidation by potential scanning

NASA Astrophysics Data System (ADS)

Majidi, Pasha; Pickup, Peter G.

2014-12-01

An ethanol electrolysis cell with aqueous ethanol supplied to the anode and nitrogen at the cathode has been operated under potential cycling conditions in order to increase the yield of carbon dioxide and thereby increase cell efficiency relative to operation at a fixed potential. At ambient temperature, faradaic yields of CO2 as high as 26% have been achieved, while only transient CO2 production was observed at constant potential. Yields increased substantially at higher temperatures, with maximum values at Pt anodes reaching 45% at constant potential and 65% under potential cycling conditions. Use of a PtRu anode increased the cell efficiency by decreasing the anode potential, but this was offset by decreased CO2 yields. Nonetheless, cycling increased the efficiency relative to constant potential. The maximum yields at PtRu and 80 °C were 13% at constant potential and 32% under potential cycling. The increased yields under cycling conditions have been attributed to periodic oxidative stripping of adsorbed CO, which occurs at lower potentials on PtRu than on Pt. These results will be important in the optimization of operating conditions for direct ethanol fuel cells and for the electrolysis of ethanol to produce clean hydrogen.

Yield Potential of Sugar Beet – Have We Hit the Ceiling?

PubMed Central

Hoffmann, Christa M.; Kenter, Christine

2018-01-01

The yield of sugar beet has continuously increased in the past decades. The question arises, whether this progress will continue in the future. A key factor for increasing yield potential of the crop is breeding progress. It was related to a shift in assimilate partitioning in the plant toward more storage carbohydrates (sucrose), whereas structural carbohydrates (leaves, cell wall compounds) unintendedly declined. The yield potential of sugar beet was estimated at 24 t sugar ha-1. For maximum yield, sufficient growth factors have to be available and the crop has to be able to fully utilize them. In sugar beet, limitations result from the lacking coincidence of maximum irradiation rates and full canopy cover, sink strength for carbon assimilation and high water demand, which cannot be met by rainfall alone. After harvest, sugar losses during storage occur. The paper discusses options for a further increase in yield potential, like autumn sowing of sugar beet, increasing sink strength and related constraints. It is prospected that yield increase by further widening the ratio of storage and structural carbohydrates will come to its natural limit as a certain cell wall stability is necessary. New challenges caused by climate change and by prolonged processing campaigns will occur. Thus breeding for improved pathogen resistance and storage properties will be even more important for successful sugar beet production than a further increase in yield potential itself. PMID:29599787

The effects of modeled microgravity on growth kinetics, antibiotic susceptibility, cold growth, and the virulence potential of a Yersinia pestis ymoA-deficient mutant and its isogenic parental strain.

PubMed

Lawal, Abidat; Kirtley, Michelle L; van Lier, Christina J; Erova, Tatiana E; Kozlova, Elena V; Sha, Jian; Chopra, Ashok K; Rosenzweig, Jason A

2013-09-01

Previously, we reported that there was no enhancement in the virulence potential (as measured by cell culture infections) of the bacterial pathogen Yersinia pestis (YP) following modeled microgravity/clinorotation growth. We have now further characterized the effects of clinorotation (CR) on YP growth kinetics, antibiotic sensitivity, cold growth, and YP's virulence potential in a murine model of infection. Surprisingly, none of the aforementioned phenotypes were altered. To better understand why CR did not enhance YP's virulence potential as it did for other bacterial pathogens, a YP ΔymoA isogenic mutant in the KIM/D27 background strain that is unable to produce the histone-like YmoA protein and influences DNA topography was used in both cell culture and murine models of infection. YmoA represses type three secretion system (T3SS) virulence gene expression in the yersiniae. Similar to our CR-grown parental YP strain data, the CR-grown ΔymoA mutant induced reduced HeLa cell cytotoxicity with concomitantly decreased Yersinia outer protein E (YopE) and low calcium response V (LcrV) antigen production and secretion. Important, however, were our findings that, although no significant differences were observed in survival of mice infected intraperitoneally with either normal gravity (NG)- or CR-grown parental YP, the ΔymoA mutant induced significantly more mortality in infected mice than did the parental strain following CR growth. Taken together, our data demonstrate that CR did enhance the virulence potential of the YP ΔymoA mutant in a murine infection model (relative to the CR-grown parental strain), despite inducing less HeLa cell rounding in our cell culture infection assay due to reduced T3SS activity. Therefore, CR, which induces a unique type of bacterial stress, might be enhancing YP's virulence potential in vivo through a T3SS-independent mechanism when the histone-like YmoA protein is absent.

Recruiting young people with a visible difference to the YP Face IT feasibility trial: a qualitative exploration of primary care staff experiences.

PubMed

Hamlet, Claire; Williamson, Heidi; Harcourt, Diana

2017-11-01

Qualitative research methods embedded within feasibility trials are of significant value as they can provide important information for a definitive trial, often unable to be fulfilled by quantitative methods alone. In addition, such information can aid researchers running other trials or evaluating interventions on a similar topic. Aim This study aimed to explore GP and nurses' experiences of recruiting to a trial exploring the feasibility of evaluating YP Face IT, a novel online psychosocial intervention to support young people with appearance-altering conditions. During the recruitment period, a focus group with participating GPs and nurses explored recruitment challenges. In addition, at the end of the recruitment period, telephone interviews were conducted with eight GPs and nurses involved in recruiting to the study, in order to inform a definitive trial of YP Face IT. Transcripts were subjected to thematic analysis. Findings Despite reporting that the study was valuable and interesting, interviewees struggled to recruit in-consultation. They appeared to lack confidence in raising the sensitive issue of a visible difference and adopted strategies to avoid mentioning the topic. Participants felt the nature of the target population, as well as pressures of the primary care environment presented challenges to recruitment, but welcomed YP Face IT as an intervention that could address unmet support needs. Primary care staff may benefit from training to help them raise the subject of a visible difference with young people in order to identify those that require additional support.

Quantifying potential yield and water-limited yield of summer maize in the North China Plain

NASA Astrophysics Data System (ADS)

Jiang, Mingnuo; Liu, Chaoshun; Chen, Maosi

2017-09-01

The North China Plain is a major food producing region in China, and climate change could pose a threat to food production in the region. Based on China Meteorological Forcing Dataset, simulating the growth of summer maize in North China Plain from 1979 to 2015 with the regional implementation of crop growth model WOFOST. The results showed that the model can reflect the potential yield and water-limited yield of Summer Maize in North China Plain through the calibration and validation of WOFOST model. After the regional implementation of model, combined with the reanalysis data, the model can better reproduce the regional history of summer maize yield in the North China Plain. The yield gap in Southeastern Beijing, southern Tianjin, southern Hebei province, Northwestern Shandong province is significant, these means the water condition is the main factor to summer maize yield in these regions.

Assessment of different gridded weather data for soybean yield simulations in Brazil

NASA Astrophysics Data System (ADS)

Battisti, R.; Bender, F. D.; Sentelhas, P. C.

2018-01-01

A high-density, well-distributed, and consistent historical weather data series is of major importance for agricultural planning and climatic risk evaluation. A possible option for regions where weather station network is irregular is the use of gridded weather data (GWD), which can be downloaded online from different sources. Based on that, the aim of this study was to assess the suitability of two GWD, AgMERRA and XAVIER, by comparing them with measured weather data (MWD) for estimating soybean yield in Brazil. The GWD and MWD were obtained for 24 locations across Brazil, considering the period between 1980 and 2010. These data were used to estimate soybean yield with DSSAT-CROPGRO-Soybean model. The comparison of MWD with GWD resulted in a good agreement between climate variables, except for solar radiation. The crop simulations with GWD and MWD resulted in a good agreement for vegetative and reproductive phases. Soybean potential yield (Yp) simulated with AgMERRA and XAVIER had a high correlation (r > 0.88) when compared to the estimates with MWD, with the RMSE of about 400 kg ha-1. For attainable yield (Ya), estimates with XAVIER resulted in a RMSE of 700 kg ha-1 against 864 kg ha-1 from AgMERRA, both compared to the simulations using MWD. Even with these differences in Ya simulations, both GWD can be considered suitable for simulating soybean growth, development, and yield in Brazil; however, with XAVIER GWD presenting a better performance for weather and crop variables assessed.

[Spatial-temporal variations of spring maize potential yields in a changing climate in Northeast China.

PubMed

Liu, Zhi Juan; Yang, Xiao Guang; Lyu, Shuo; Wang, Jing; Lin, Xiao Mao

2018-01-01

Based on meteorological data, agro-meteorological observations, and agricultural statistical data in Northeast China (NEC), by using the validated Agricultural Production System sIMulator (APSIM-maize), the potential, attainable, potential farmers' and actual farmers' yields of spring maize during the period 1961 to 2015 were analyzed, and the effects of climate variation on maize potential yield in NEC were quantified. Results indicated that the potential yield of spring maize was 12.2 t·hm -2 during the period 1961 to 2015, with those in northeast being lower than southwest within the study region. The attainable yield of spring maize was 11.3 t·hm -2 , and showed a similar spatial distribution with potential yield. Under the current farmers' management practices, mean simulated potential and actual farmers' yields were 6.5 and 4.5 t·hm -2 , respectively. Assuming there were no changes in cultivars and management practices in NEC, the mean potential, attainable, and potential farmers' yields of spring maize would decrease by 0.34, 0.25 and 0.10 t·hm -2 per decade in NEC. However, the actual farmers' yields increased with the value of 1.27 t·hm -2 per decade averaged over NEC. Due to climate variation, year-to-year variations of spring maize potential, attainable, and potential farmers' yields were significant, ranging from 10.0 to 14.4, 9.8 to 13.3, 4.4 to 8.5 t·hm -2 , respectively.

Assessing the Potential Oleoresin Yields of Slash Pine Progenies at Juvenile Ages

Treesearch

A.E. Squillace; Charles R. Gansel

1968-01-01

The potential oleoresin yields of slash pine progenies can be assessed at juvenile ages, 7 to 8 years earlier than with previous methods. Seeds are sown in peat pots, outplanted shortly after germination at a spacing of 14 by 3 feet, and given intensive cultural treatment. At 26 years from seed, when the trees average about 9 feet tall, their potential yields are...

Identification of potentially high yielding irradiated cassava ‘Gajah’ genotype with different geographic coordinates

NASA Astrophysics Data System (ADS)

Subekti, I.; Khumaida, N.; Ardie, SW

2017-01-01

Cassava is one of the main and important carbohydrate producing crops in Indonesia. Thus cassava production and its tuber quality need to be improved. ‘Gajah’ genotype is a local genotypes cassava from East Kalimantan, has high potential yield (> 60 ton Ha-1). However, the harvest time of this genotype is quite long (>= 12 months). The objective of this research was to identify the high yielding cassava mutants from the gamma rays irradiated ‘Gajah’ genotype at M1V3 population and potential yield at different location. Several putative cassava mutants (12 mutants) were planted in Cikabayan Experimental Field, IPB from March 2015 to March 2016 and the yields compared with the same genotype grown at different location by seeing its coordinates to observe the potential yield. Our result showed that the fresh tuber weight per plant of some putative mutants could reach more than 8 kg (yield potential of 64 ton Ha-1). The harvested tubers also had sweet flavor, although the tubers of some putative mutants were bitter. Based on previous research study, the different geographic coordinate has resulted variability on fresh tuber yield. It seems that it needs to observe the stability of ‘Gajah’- irradiated mutants in several location in Java Island.

Yield potential and nitrogen requirements of Miscanthus × giganteus on eroded soil

USDA-ARS?s Scientific Manuscript database

Miscanthus × giganteus yield and fertilizer N requirements have been well studied in Europe and parts of the United States, but few reports have investigated its production on eroded claypan soils economically marginal for grain crops. This study was conducted to evaluate yield potential and fertili...

Study protocol of the YP Face IT feasibility study: comparing an online psychosocial intervention versus treatment as usual for adolescents distressed by appearance-altering conditions/injuries.

PubMed

Williamson, Heidi; Hamlet, Claire; White, Paul; Marques, Elsa M R; Cadogan, Julia; Perera, Rohan; Rumsey, Nichola; Hayward, Leighton; Harcourt, Diana

2016-10-03

A significant number of adolescents suffer extensive and enduring difficulties such as social anxiety, body image dissatisfaction, low self-esteem and bullying as a result of conditions or injuries that affect their appearance (eg, craniofacial and skin conditions, treatment side effects and scarring). Evidence-based psychosocial interventions to meet their specific needs are currently lacking. YP Face IT, developed by the UK's Centre for Appearance Research in collaboration with clinical experts and young people, is an innovative online psychosocial intervention designed to offer this group immediate support, advice and coping strategies. It has been endorsed by young people, their parents/carers, GPs, clinical psychologists and health professionals working with those affected by appearance-related conditions. Young people aged 12-17 with an appearance-altering condition/injury that self-identify as experiencing appearance-related distress, teasing or bullying will be invited to participate via GP practices and UK charities. Consenting participants will be randomised to the intervention (YP Face IT) or the treatment as usual (TAU) control group. Outcome measures will be completed by young people and their parents/carers at baseline, 13, 26 and 52 weeks. Primary outcome measures will be the Body Esteem Scale and the Social Anxiety Scale for Adolescents. Participants will complete other health-related outcome measures and resource use questionnaires for health economic analysis. We will assess recruitment rates, acceptability of the YP Face IT programme, adherence and retention to treatment, questionnaire completion rates, variation of TAU in Primary Care and the feasibility of GP practice staff supervising young people's use of YP Face IT. This feasibility trial protocol (V.1, 3 March 2014), received a favourable ethical opinion from the NRES Committee South West-Frenchay (reference number 14/SW/0058). Findings will be disseminated through academic peer

Increasing Selenium and Yellow Pigment Concentrations in Foxtail Millet (Setaria italica L.) Grain with Foliar Application of Selenite.

PubMed

Ning, Na; Yuan, Xiang-Yang; Dong, Shu-Qi; Wen, Yin-Yuan; Gao, Zhen-Pan; Guo, Mei-Jun; Guo, Ping-Yi

2016-03-01

Although addition of selenium (Se) is known to increase Se in crops, it is unclear whether exogenous Se is linked to nutritional and functional components in foxtail millet (Setaria italica L.). In this study, we examined the potential of increasing Se and yellow pigment (YP) in foxtail millet grain by foliar application of Se. Field experiments were conducted during the growing season of foxtail millet in 2013 and 2014 to assess the effects of foliar spray of sodium selenite (10-210 g Se ha(-1)) on the yield, Se uptake and accumulation, total YP, and microminerals in the grain. Average grain yields with Se application were 5.60 and 4.53 t ha(-1) in the 2 years, showing no significant differences from the unfertilized control. However, grain Se concentration increased linearly with Se application rate, by 8.92 and 6.09 μg kg(-1) in the 2 years with application of 1 g Se ha(-1) (maximum grain recovery rates of Se fertilizer, 52 and 28 %). Likewise, total grain YP concentration markedly increased by 0.038 and 0.031 mg kg(-1) in the 2 years with application of 1 g Se ha(-1). Grain Mn, Cu, Fe, and Zn concentrations were not significantly affected by Se application. This study indicated that foliar application of Se effectively and reliably increased the concentrations of Se and YP in foxtail millet grain without affecting the yield or mineral micronutrient concentrations. Thus, foliar-applied selenite has a significant potential to increase the concentrations of selenium and YP (putative lutein (Shen, J Cereal Sci 61:86-93, 2015; Abdel-Aal, Cereal Chem 79:455-457, 2002; Abdel-Aal, J Agric Food Chem 55:787-794, 2007)) of foxtail millet and, thus, the health benefits of this crop.

Ecological intensification of cereal production systems: yield potential, soil quality, and precision agriculture.

PubMed

Cassman, K G

1999-05-25

Wheat (Triticum aestivum L.), rice (Oryza sativa L.), and maize (Zea mays L.) provide about two-thirds of all energy in human diets, and four major cropping systems in which these cereals are grown represent the foundation of human food supply. Yield per unit time and land has increased markedly during the past 30 years in these systems, a result of intensified crop management involving improved germplasm, greater inputs of fertilizer, production of two or more crops per year on the same piece of land, and irrigation. Meeting future food demand while minimizing expansion of cultivated area primarily will depend on continued intensification of these same four systems. The manner in which further intensification is achieved, however, will differ markedly from the past because the exploitable gap between average farm yields and genetic yield potential is closing. At present, the rate of increase in yield potential is much less than the expected increase in demand. Hence, average farm yields must reach 70-80% of the yield potential ceiling within 30 years in each of these major cereal systems. Achieving consistent production at these high levels without causing environmental damage requires improvements in soil quality and precise management of all production factors in time and space. The scope of the scientific challenge related to these objectives is discussed. It is concluded that major scientific breakthroughs must occur in basic plant physiology, ecophysiology, agroecology, and soil science to achieve the ecological intensification that is needed to meet the expected increase in food demand.

Sinusoidal potential cycling operation of a direct ethanol fuel cell to improving carbon dioxide yields

NASA Astrophysics Data System (ADS)

Majidi, Pasha; Pickup, Peter G.

2014-12-01

A direct ethanol fuel cell has been operated under sinusoidal (AC) potential cycling conditions in order to increase the yield of carbon dioxide and thereby increase cell efficiency relative to operation at a fixed potential. At 80 °C, faradaic yields of CO2 as high as 25% have been achieved with a PtRu anode catalyst, while the maximum CO2 production at constant potential was 13%. The increased yields under cycling conditions have been attributed to periodic oxidative stripping of adsorbed CO. These results will be important in the optimization of operating conditions for direct ethanol fuel cells, where the benefits of potential cycling are projected to increase as catalysts that produce CO2 more efficiently are implemented.

Drought Tolerance during Reproductive Development is Important for Increasing wheat yield Potential under Climate change in Europe.

PubMed

Senapati, Nimai; Stratonovitch, Pierre; Paul, Matthew J; Semenov, Mikhail A

2018-06-12

Drought stress during reproductive development could drastically reduce grain number and wheat yield, but quantitative evaluation of such effect is unknown under climate change. The objectives of this study were to a) evaluate potential yield benefits of drought tolerance during reproductive development for wheat ideotypes under climate change in Europe, and b) identify potential cultivar parameters for improvement. We used the Sirius wheat model to optimise drought tolerant (DT) and drought sensitive (DS) wheat ideotypes under future 2050 climate scenario at 13 contrasting sites, representing major wheat growing regions in Europe. Averaged over the sites, DT ideotypes achieved 13.4% greater yield compared to DS, with the double yield stability for DT. However, the performances of the ideotypes were site dependent. Mean yield of DT was 28-37% greater compared to DS in southern Europe. In contrast, no yield difference (≤ 1%) between ideotypes was found in north-western Europe. An intermediate yield benefit of 10-23% was found due to drought tolerance in central and eastern Europe. We conclude that tolerance to drought stress during reproductive development is important for high yield potentials and greater yield stability of wheat under climate change in Europe.

The effect of low shear force on the virulence potential of Yersinia pestis: new aspects that space-like growth conditions and the final frontier can teach us about a formidable pathogen.

PubMed

Rosenzweig, Jason A; Chopra, Ashok K

2012-01-01

Manned space exploration has created a need to evaluate the effects of space-like stress (SLS) on pathogenic and opportunistic microbes. Interestingly, several Gram-negative enteric pathogens, e.g., Salmonella enterica serovar Typhimurium, have revealed a transient hyper-virulent phenotype following simulated microgravity (SMG) or actual space flight exposures. We have explored the virulence potential of Yersinia pestis KIM/D27 (YP) following exposure to mechanical low shear forces associated with SMG. Our experimental results demonstrated that SMG-grown YP was decreased in its induced HeLa cell cytotoxicity, suggesting that SMG somehow compromises T3SS functions. This was confirmed by an actual reduced amount of effector protein production and secretion through the T3SS injectisome. Also, SMG-grown YP proliferated less than their NG-grown counterparts did during an 8-h macrophage infection. Presently, we are evaluating the influence of SMG on various KIM/D27 mutant strains to further understanding of our initial phenomenology described above. Taken together, characterizing YP grown under the low shear forces of SMG can provide new insights into its pathogenesis and potentially uncover new targets that could be exploited for the development of novel antimicrobials as well as potential live-attenuated vaccines.

Bird Communities and Biomass Yields in Potential Bioenergy Grasslands

PubMed Central

Blank, Peter J.; Sample, David W.; Williams, Carol L.; Turner, Monica G.

2014-01-01

Demand for bioenergy is increasing, but the ecological consequences of bioenergy crop production on working lands remain unresolved. Corn is currently a dominant bioenergy crop, but perennial grasslands could produce renewable bioenergy resources and enhance biodiversity. Grassland bird populations have declined in recent decades and may particularly benefit from perennial grasslands grown for bioenergy. We asked how breeding bird community assemblages, vegetation characteristics, and biomass yields varied among three types of potential bioenergy grassland fields (grass monocultures, grass-dominated fields, and forb-dominated fields), and assessed tradeoffs between grassland biomass production and bird habitat. We also compared the bird communities in grassland fields to nearby cornfields. Cornfields had few birds compared to perennial grassland fields. Ten bird Species of Greatest Conservation Need (SGCN) were observed in perennial grassland fields. Bird species richness and total bird density increased with forb cover and were greater in forb-dominated fields than grass monocultures. SGCN density declined with increasing vertical vegetation density, indicating that tall, dense grassland fields managed for maximum biomass yield would be of lesser value to imperiled grassland bird species. The proportion of grassland habitat within 1 km of study sites was positively associated with bird species richness and the density of total birds and SGCNs, suggesting that grassland bioenergy fields may be more beneficial for grassland birds if they are established near other grassland parcels. Predicted total bird density peaked below maximum biomass yields and predicted SGCN density was negatively related to biomass yields. Our results indicate that perennial grassland fields could produce bioenergy feedstocks while providing bird habitat. Bioenergy grasslands promote agricultural multifunctionality and conservation of biodiversity in working landscapes. PMID:25299593

Preliminary development and psychometric evaluation of an unmet needs measure for adolescents and young adults with cancer: the Cancer Needs Questionnaire - Young People (CNQ-YP).

PubMed

Clinton-McHarg, Tara; Carey, Mariko; Sanson-Fisher, Rob; D'Este, Catherine; Shakeshaft, Anthony

2012-01-30

Adolescents and young adult (AYA) cancer survivors may have unique physical, psychological and social needs due to their cancer occurring at a critical phase of development. The aim of this study was to develop a psychometrically rigorous measure of unmet need to capture the specific needs of this group. Items were developed following a comprehensive literature review, focus groups with AYAs, and feedback from health care providers, researchers and other professionals. The measure was pilot tested with 32 AYA cancer survivors recruited through a state-based cancer registry to establish face and content validity. A main sample of 139 AYA cancer patients and survivors were recruited through seven treatment centres and invited to complete the questionnaire. To establish test-retest reliability, a sub-sample of 34 participants completed the measure a second time. Exploratory factor analysis was performed and the measure was assessed for internal consistency, discriminative validity, potential responsiveness and acceptability. The Cancer Needs Questionnaire - Young People (CNQ-YP) has established face and content validity, and acceptability. The final measure has 70 items and six factors: Treatment Environment and Care (33 items); Feelings and Relationships (14 items); Daily Life (12 items); Information and Activities (5 items); Education (3 items); and Work (3 items). All domains achieved Cronbach's alpha values greater than 0.80. Item-to-item test-retest reliability was also high, with all but four items reaching weighted kappa values above 0.60. The CNQ-YP is the first multi-dimensional measure of unmet need which has been developed specifically for AYA cancer patients and survivors. The measure displays a strong factor structure, and excellent internal consistency and test-retest reliability. However, the small sample size has implications for the reliability of the statistical analyses undertaken, particularly the exploratory factor analysis. Future studies with a

Preliminary development and psychometric evaluation of an unmet needs measure for adolescents and young adults with cancer: the Cancer Needs Questionnaire - Young People (CNQ-YP)

PubMed Central

2012-01-01

Background Adolescents and young adult (AYA) cancer survivors may have unique physical, psychological and social needs due to their cancer occurring at a critical phase of development. The aim of this study was to develop a psychometrically rigorous measure of unmet need to capture the specific needs of this group. Methods Items were developed following a comprehensive literature review, focus groups with AYAs, and feedback from health care providers, researchers and other professionals. The measure was pilot tested with 32 AYA cancer survivors recruited through a state-based cancer registry to establish face and content validity. A main sample of 139 AYA cancer patients and survivors were recruited through seven treatment centres and invited to complete the questionnaire. To establish test-retest reliability, a sub-sample of 34 participants completed the measure a second time. Exploratory factor analysis was performed and the measure was assessed for internal consistency, discriminative validity, potential responsiveness and acceptability. Results The Cancer Needs Questionnaire - Young People (CNQ-YP) has established face and content validity, and acceptability. The final measure has 70 items and six factors: Treatment Environment and Care (33 items); Feelings and Relationships (14 items); Daily Life (12 items); Information and Activities (5 items); Education (3 items); and Work (3 items). All domains achieved Cronbach's alpha values greater than 0.80. Item-to-item test-retest reliability was also high, with all but four items reaching weighted kappa values above 0.60. Conclusions The CNQ-YP is the first multi-dimensional measure of unmet need which has been developed specifically for AYA cancer patients and survivors. The measure displays a strong factor structure, and excellent internal consistency and test-retest reliability. However, the small sample size has implications for the reliability of the statistical analyses undertaken, particularly the exploratory

Insect pests and yield potential of vegetable soybean (Endamame) produced in Georgia

USDA-ARS?s Scientific Manuscript database

A series of replicated field experiments was conducted with vegetable soybean (edamame), Glycine max (L.) Merrill, to assess the impacts of cultivars, planting dates, and insecticidal controls on insect pest abundance, crop damage and yield potential. The velvetbean caterpillar, Anticarsia gemmatali...

Yield estimation of corn with multispectral data and the potential of using imaging spectrometers

NASA Astrophysics Data System (ADS)

Bach, Heike

1997-05-01

In the frame of the special yield estimation, a regular procedure conducted for the European Union to more accurately estimate agricultural yield, a project was conducted for the state minister for Rural Environment, Food and Forestry of Baden-Wuerttemberg, Germany) to test remote sensing data with advanced yield formation models for accuracy and timelines of yield estimation of corn. The methodology employed uses field-based plant parameter estimation from atmospherically corrected multitemporal/multispectral LANDSAT-TM data. An agrometeorological plant-production-model is used for yield prediction. Based solely on 4 LANDSAT-derived estimates and daily meteorological data the grain yield of corn stands was determined for 1995. The modeled yield was compared with results independently gathered within the special yield estimation for 23 test fields in the Upper Rhine Valley. The agrement between LANDSAT-based estimates and Special Yield Estimation shows a relative error of 2.3 percent. The comparison of the results for single fields shows, that six weeks before harvest the grain yield of single corn fields was estimated with a mean relative accuracy of 13 percent using satellite information. The presented methodology can be transferred to other crops and geographical regions. For future applications hyperspectral sensors show great potential to further enhance the results or yield prediction with remote sensing.

Altitude-Wind-Tunnel Investigation of Performance of Several Propellers on YP-47M Airplane at High Blade Loadings. 4; Curtiss 732-1C2-0 Four-Blade Propeller

NASA Technical Reports Server (NTRS)

Saari, Martin J.; Sorin, Solomon M.

1946-01-01

An altitude-wind-tunnel investigation has been made to determine the performance of a Curtiss 732-1C2-0 four-blade propeller on a YP-47M airplane at high blade loadings and engine power. Propeller characteristics were obtained for a range of power coefficients from 0.30 to 1.00 at free-stream Mach numbers of 0.40 and .50.

High-Speed Wind-Tunnel Tests of a Model of the Lockheed YP-80A Airplane Including Correlation with Flight Tests and Tests of Dive-Recovery Flaps

NASA Technical Reports Server (NTRS)

Cleary, Joseph W.; Gray, Lyle J.

1947-01-01

This report contains the results of tests of a 1/3-scale model of the Lockheed YP-90A "Shooting Star" airplane and a comparison of drag, maximum lift coefficient, and elevator angle required for level flight as measured in the wind tunnel and in flight. Included in the report are the general aerodynamic characteristics of the model and of two types of dive-recovery flaps, one at several positions along the chord on the lower surface of the wing and the other on the lower surface of the fuselage. The results show good agreement between the flight and wind-tunnel measurements at all Mach numbers. The results indicate that the YP-80A is controllable in pitch by the elevators to a Mach number of at least 0.85. The fuselage dive-recovery flaps are effective for producing a climbing moment and increasing the drag at Mach numbers up to at least 0.8. The wing dive-recovery flaps are most effective for producing a climbing moment at 0.75 Mach number. At 0.85 Mach number, their effectiveness is approximately 50 percent of the maximum. The optimum position for the wing dive-recovery flaps to produce a climbing moment is at approximately 35 percent of the chord.

Assessing potential sustainable wood yield

Treesearch

Robert F. Powers

2001-01-01

Society is making unprecedented demands on world forests to produce and sustain many values. Chief among them is wood supply, and concerns are rising globally about the ability of forests to meet increasing needs. Assessing this is not easy. It requires a basic understanding of the principles governing forest productivity: how wood yield varies with tree and stand...

Yield gaps and yield relationships in US soybean production systems

USDA-ARS?s Scientific Manuscript database

The magnitude of yield gaps (YG) (potential yield – farmer yield) provides some indication of the prospects for increasing crop yield to meet the food demands of future populations. Quantile regression analysis was applied to county soybean [Glycine max (L.) Merrill] yields (1971 – 2011) from Kentuc...

Global bioenergy potentials from agricultural land in 2050: Sensitivity to climate change, diets and yields

PubMed Central

Haberl, Helmut; Erb, Karl-Heinz; Krausmann, Fridolin; Bondeau, Alberte; Lauk, Christian; Müller, Christoph; Plutzar, Christoph; Steinberger, Julia K.

2011-01-01

There is a growing recognition that the interrelations between agriculture, food, bioenergy, and climate change have to be better understood in order to derive more realistic estimates of future bioenergy potentials. This article estimates global bioenergy potentials in the year 2050, following a “food first” approach. It presents integrated food, livestock, agriculture, and bioenergy scenarios for the year 2050 based on a consistent representation of FAO projections of future agricultural development in a global biomass balance model. The model discerns 11 regions, 10 crop aggregates, 2 livestock aggregates, and 10 food aggregates. It incorporates detailed accounts of land use, global net primary production (NPP) and its human appropriation as well as socioeconomic biomass flow balances for the year 2000 that are modified according to a set of scenario assumptions to derive the biomass potential for 2050. We calculate the amount of biomass required to feed humans and livestock, considering losses between biomass supply and provision of final products. Based on this biomass balance as well as on global land-use data, we evaluate the potential to grow bioenergy crops and estimate the residue potentials from cropland (forestry is outside the scope of this study). We assess the sensitivity of the biomass potential to assumptions on diets, agricultural yields, cropland expansion and climate change. We use the dynamic global vegetation model LPJmL to evaluate possible impacts of changes in temperature, precipitation, and elevated CO2 on agricultural yields. We find that the gross (primary) bioenergy potential ranges from 64 to 161 EJ y−1, depending on climate impact, yields and diet, while the dependency on cropland expansion is weak. We conclude that food requirements for a growing world population, in particular feed required for livestock, strongly influence bioenergy potentials, and that integrated approaches are needed to optimize food and bioenergy supply

Biochemical methane potential, biodegradability, alkali treatment and influence of chemical composition on methane yield of yard wastes.

PubMed

Gunaseelan, Victor Nallathambi

2016-03-01

In this study, the biochemical CH4 potential, rate, biodegradability, NaOH treatment and the influence of chemical composition on CH4 yield of yard wastes generated from seven trees were examined. All the plant parts were sampled for their chemical composition and subjected to the biochemical CH4 potential assay. The component parts exhibited significant variation in biochemical CH4 potential, which was reflected in their ultimate CH4 yields that ranged from 109 to 382 ml g(-1) volatile solids added and their rate constants that ranged from 0.042 to 0.173 d(-1). The biodegradability of the yard wastes ranged from 0.26 to 0.86. Variation in the biochemical CH4 potential of the yard wastes could be attributed to variation in the chemical composition of the different fractions. In the Thespesia yellow withered leaf, Tamarindus fruit pericarp and Albizia pod husk, NaOH treatment enhanced the ultimate CH4 yields by 17%, 77% and 63%, respectively, and biodegradability by 15%, 77% and 61%, respectively, compared with the untreated samples. The effectiveness of NaOH treatment varied for different yard wastes, depending on the amounts of acid detergent fibre content. Gliricidia petals, Prosopis leaf, inflorescence and immature pod, Tamarindus seeds, Albizia seeds, Cassia seeds and Delonix seeds exhibited CH4 yields higher than 300 ml g(-1) volatile solids added. Multiple linear regression models for predicting the ultimate CH4 yield and biodegradability of yard wastes were designed from the results of this work. © The Author(s) 2016.

[Comparison of potential yield and resource utilization efficiency of main food crops in three provinces of Northeast China under climate change].

PubMed

Wang, Xiao-yu; Yang, Xiao-guang; Sun, Shuang; Xie, Wen-juan

2015-10-01

Based on the daily data of 65 meteorological stations from 1961 to 2010 and the crop phenology data in the potential cultivation zones of thermophilic and chimonophilous crops in Northeast China, the crop potential yields were calculated through step-by-step correction method. The spatio-temporal distribution of the crop potential yields at different levels was analyzed. And then we quantified the limitations of temperature and precipitation on the crop potential yields and compared the differences in the climatic resource utilization efficiency. The results showed that the thermal potential yields of six crops (including maize, rice, spring wheat, sorghum, millet and soybean) during the period 1961-2010 deceased from west to east. The climatic potential yields of the five crops (spring wheat not included) were higher in the south than in the north. The potential yield loss rate due to temperature limitations of the six crops presented a spatial distribution pattern and was higher in the east than in the west. Among the six main crops, the yield potential loss rate due to temperature limitation of the soybean was the highest (51%), and those of the other crops fluctuated within the range of 33%-41%. The potential yield loss rate due to water limitation had an obvious regional difference, and was high in Songnen Plain and Changbai Mountains. The potential yield loss rate of spring wheat was the highest (50%), and those of the other four rainfed crops fluctuated within the range of 8%-10%. The solar energy utilization efficiency of the six main crops ranged from 0.9% to 2.7%, in the order of maize> sorghum>rice>millet>spring wheat>soybean. The precipitation utilization efficiency of the maize, sorghum, spring wheat, millet and soybean under rainfed conditions ranged from 8 to 35 kg . hm-2 . mm-1, in the order of maize>sorghum>spring wheat>millet>soybean. In those areas with lower efficiency of solar energy utilization and precipitation utilization, such as Changbai

Quantifying the potential for reservoirs to secure future surface water yields in the world’s largest river basins

NASA Astrophysics Data System (ADS)

Liu, Lu; Parkinson, Simon; Gidden, Matthew; Byers, Edward; Satoh, Yusuke; Riahi, Keywan; Forman, Barton

2018-04-01

Surface water reservoirs provide us with reliable water supply, hydropower generation, flood control and recreation services. Yet reservoirs also cause flow fragmentation in rivers and lead to flooding of upstream areas, thereby displacing existing land-use activities and ecosystems. Anticipated population growth and development coupled with climate change in many regions of the globe suggests a critical need to assess the potential for future reservoir capacity to help balance rising water demands with long-term water availability. Here, we assess the potential of large-scale reservoirs to provide reliable surface water yields while also considering environmental flows within 235 of the world’s largest river basins. Maps of existing cropland and habitat conservation zones are integrated with spatially-explicit population and urbanization projections from the Shared Socioeconomic Pathways to identify regions unsuitable for increasing water supply by exploiting new reservoir storage. Results show that even when maximizing the global reservoir storage to its potential limit (∼4.3–4.8 times the current capacity), firm yields would only increase by about 50% over current levels. However, there exist large disparities across different basins. The majority of river basins in North America are found to gain relatively little firm yield by increasing storage capacity, whereas basins in Southeast Asia display greater potential for expansion as well as proportional gains in firm yield under multiple uncertainties. Parts of Europe, the United States and South America show relatively low reliability of maintaining current firm yields under future climate change, whereas most of Asia and higher latitude regions display comparatively high reliability. Findings from this study highlight the importance of incorporating different factors, including human development, land-use activities, and climate change, over a time span of multiple decades and across a range of different

Molecular characterization of a polymorphic 3-Mb deletion at chromosome Yp11.2 containing the AMELY locus in Singapore and Malaysia populations.

PubMed

Yong, Rita Y Y; Gan, Linda S H; Chang, Yuet Meng; Yap, Eric P H

2007-11-01

Amelogenin paralogs on Chromosome X (AMELX) and Y (AMELY) are commonly used sexing markers. Interstitial deletion of Yp involving the AMELY locus has previously been reported. The combined frequency of the AMELY null allele in Singapore and Malaysia populations is 2.7%, 0.6% in Indian and Malay ethnic groups respectively. It is absent among 541 Chinese screened. The null allele in this study belongs to 3 Y haplogroups; J2e1 (85.7%), F* (9.5%) and D* (4.8%). Low and high-resolution STS mapping, followed by sequence analysis of breakpoint junction confirmed a large deletion of 3 to 3.7-Mb located at the Yp11.2 region. Both breakpoints were located in TSPY repeat arrays, suggesting a non-allelic homologous recombination (NAHR) mechanism of deletion. All regional null samples shared identical breakpoint sequences according to their haplogroup affiliation, providing molecular evidence of a common ancestry origin for each haplogroup, and at least 3 independent deletion events recurred in history. The estimated ages based on Y-SNP and STR analysis were approximately 13.5 +/- 3.1 kyears and approximately 0.9 +/- 0.9 kyears for the J2e1 and F* mutations, respectively. A novel polymorphism G > A at Y-GATA-H4 locus in complete linkage disequilibrium with J2e1 null mutations is a more recent event. This work re-emphasizes the need to include other sexing markers for gender determination in certain regional populations. The frequency difference among global populations suggests it constitutes another structural variation locus of human chromosome Y. The breakpoint sequences provide further information to a better understanding of the NAHR mechanism and DNA rearrangements due to higher order genomic architecture.

Yield and yield gaps in central U.S. corn production systems

USDA-ARS?s Scientific Manuscript database

The magnitude of yield gaps (YG) (potential yield – farmer yield) provides some indication of the prospects for increasing crop yield. Quantile regression analysis was applied to county maize (Zea mays L.) yields (1972 – 2011) from Kentucky, Iowa and Nebraska (irrigated) (total of 115 counties) to e...

Yield Potential of Soil Water and Its Sustainability for Dryland Spring Maize with Plastic Film Mulch on the Loess Plateau

NASA Astrophysics Data System (ADS)

Lin, Wen; Liu, Wenzhao

2016-04-01

Plastic film mulch(PM) is an agronomic measure widely used in the dryland spring maize production system on the Loess Plateau of China. The measure can greatly increase yield of dryland maize due to its significant effects on soil water conservation. Few researches have been done to investigate how the yield potential is impacted by PM. The yield-water use (ET) boundary equation raised by French and Schultz provides a simple approach to calculate crop water limited yield potential and gives a benchmark for farmers in managing their crops. However, method used in building the equation is somewhat arbitrary and has no strict principle, which leads to the uncertainty of equation when it is applied. Though using PM can increase crop yield, it increases soil temperature, promotes crop growth and increases the water transpired by crop, which further leads to high water consumption as compared with crops without PM. This means that PM may lead to the overuse of soil water and hence is unsustainable in a long run. This research is mainly focused on the yield potential and sustainability of PMing for spring maize on the Loess Plateau. A principle that may be utilized by any other researchers was proposed based on French & Schultz's boundary equation and on part of quantile regression theory. We used a data set built by collecting the experimental data from published papers and analyzed the water-limited yield potential of spring maize on the Loess Plateau. Moreover, maize yield and soil water dynamics under PM were investigated by a long-term site field experiment. Results show that on the Loess Plateau, the water limited yield potential can be calculated using the boundary equation y = 60.5×(x - 50), with a platform yield of 15954 kghm-2 after the water use exceeds 314 mm. Without PMing, the water limited yield potential can be estimated by the boundary equation y = 47.5×(x - 62.3) , with a platform yield of 12840 kghm-2 when the water use exceeds 325 mm, which

Modeling the yield potential of dryland canola under current and future climates in California

NASA Astrophysics Data System (ADS)

George, N.; Kaffka, S.; Beeck, C.; Bucaram, S.; Zhang, J.

2012-12-01

Models predict that the climate of California will become hotter, drier and more variable under future climate change scenarios. This will lead to both increased irrigation demand and reduced irrigation water availability. In addition, it is predicted that most common Californian crops will suffer a concomitant decline in productivity. To remain productive and economically viable, future agricultural systems will need to have greater water use efficiency, tolerance of high temperatures, and tolerance of more erratic temperature and rainfall patterns. Canola (Brassica napus) is the third most important oilseed globally, supporting large and well-established agricultural industries in Canada, Europe and Australia. It is an agronomically useful and economically valuable crop, with multiple end markets, that can be grown in California as a dryland winter rotation with little to no irrigation demand. This gives canola great potential as a new crop for Californian farmers both now and as the climate changes. Given practical and financial limitations it is not always possible to immediately or widely evaluate a crop in a new region. Crop production models are therefore valuable tools for assessing the potential of new crops, better targeting further field research, and refining research questions. APSIM is a modular modeling framework developed by the Agricultural Production Systems Research Unit in Australia, it combines biophysical and management modules to simulate cropping systems. This study was undertaken to examine the yield potential of Australian canola varieties having different water requirements and maturity classes in California using APSIM. The objective of the work was to identify the agricultural regions of California most ideally suited to the production of Australian cultivars of canola and to simulate the production of canola in these regions to estimate yield-potential. This will establish whether the introduction and in-field evaluation of better

Modern maize hybrids in Northeast China exhibit increased yield potential and resource use efficiency despite adverse climate change.

PubMed

Chen, Xiaochao; Chen, Fanjun; Chen, Yanling; Gao, Qiang; Yang, Xiaoli; Yuan, Lixing; Zhang, Fusuo; Mi, Guohua

2013-03-01

The impact of global changes on food security is of serious concern. Breeding novel crop cultivars adaptable to climate change is one potential solution, but this approach requires an understanding of complex adaptive traits for climate-change conditions. In this study, plant growth, nitrogen (N) uptake, and yield in relation to climatic resource use efficiency of nine representative maize cultivars released between 1973 and 2000 in China were investigated in a 2-year field experiment under three N applications. The Hybrid-Maize model was used to simulate maize yield potential in the period from 1973 to 2011. During the past four decades, the total thermal time (growing degree days) increased whereas the total precipitation and sunshine hours decreased. This climate change led to a reduction of maize potential yield by an average of 12.9% across different hybrids. However, the potential yield of individual hybrids increased by 118.5 kg ha(-1)  yr(-1) with increasing year of release. From 1973 to 2000, the use efficiency of sunshine hours, thermal time, and precipitation resources increased by 37%, 40%, and 41%, respectively. The late developed hybrids showed less reduction in yield potential in current climate conditions than old cultivars, indicating some adaptation to new conditions. Since the mid-1990s, however, the yield impact of climate change exhibited little change, and even a slight worsening for new cultivars. Modern breeding increased ear fertility and grain-filling rate, and delayed leaf senescence without modification in net photosynthetic rate. The trade-off associated with delayed leaf senescence was decreased grain N concentration rather than increased plant N uptake, therefore N agronomic efficiency increased simultaneously. It is concluded that modern maize hybrids tolerate the climatic changes mainly by constitutively optimizing plant productivity. Maize breeding programs in the future should pay more attention to cope with the limiting

Improving yield potential in crops under elevated CO2: Integrating the photosynthetic and nitrogen utilization efficiencies

PubMed Central

Kant, Surya; Seneweera, Saman; Rodin, Joakim; Materne, Michael; Burch, David; Rothstein, Steven J.; Spangenberg, German

2012-01-01

Increasing crop productivity to meet burgeoning human food demand is challenging under changing environmental conditions. Since industrial revolution atmospheric CO2 levels have linearly increased. Developing crop varieties with increased utilization of CO2 for photosynthesis is an urgent requirement to cope with the irreversible rise of atmospheric CO2 and achieve higher food production. The primary effects of elevated CO2 levels in most crop plants, particularly C3 plants, include increased biomass accumulation, although initial stimulation of net photosynthesis rate is only temporal and plants fail to sustain the maximal stimulation, a phenomenon known as photosynthesis acclimation. Despite this acclimation, grain yield is known to marginally increase under elevated CO2. The yield potential of C3 crops is limited by their capacity to exploit sufficient carbon. The “C fertilization” through elevated CO2 levels could potentially be used for substantial yield increase. Rubisco is the rate-limiting enzyme in photosynthesis and its activity is largely affected by atmospheric CO2 and nitrogen availability. In addition, maintenance of the C/N ratio is pivotal for various growth and development processes in plants governing yield and seed quality. For maximizing the benefits of elevated CO2, raising plant nitrogen pools will be necessary as part of maintaining an optimal C/N balance. In this review, we discuss potential causes for the stagnation in yield increases under elevated CO2 levels and explore possibilities to overcome this limitation by improved photosynthetic capacity and enhanced nitrogen use efficiency. Opportunities of engineering nitrogen uptake, assimilatory, and responsive genes are also discussed that could ensure optimal nitrogen allocation toward expanding source and sink tissues. This might avert photosynthetic acclimation partially or completely and drive for improved crop production under elevated CO2 levels. PMID:22833749

Improving yield potential in crops under elevated CO(2): Integrating the photosynthetic and nitrogen utilization efficiencies.

PubMed

Kant, Surya; Seneweera, Saman; Rodin, Joakim; Materne, Michael; Burch, David; Rothstein, Steven J; Spangenberg, German

2012-01-01

Increasing crop productivity to meet burgeoning human food demand is challenging under changing environmental conditions. Since industrial revolution atmospheric CO(2) levels have linearly increased. Developing crop varieties with increased utilization of CO(2) for photosynthesis is an urgent requirement to cope with the irreversible rise of atmospheric CO(2) and achieve higher food production. The primary effects of elevated CO(2) levels in most crop plants, particularly C(3) plants, include increased biomass accumulation, although initial stimulation of net photosynthesis rate is only temporal and plants fail to sustain the maximal stimulation, a phenomenon known as photosynthesis acclimation. Despite this acclimation, grain yield is known to marginally increase under elevated CO(2). The yield potential of C(3) crops is limited by their capacity to exploit sufficient carbon. The "C fertilization" through elevated CO(2) levels could potentially be used for substantial yield increase. Rubisco is the rate-limiting enzyme in photosynthesis and its activity is largely affected by atmospheric CO(2) and nitrogen availability. In addition, maintenance of the C/N ratio is pivotal for various growth and development processes in plants governing yield and seed quality. For maximizing the benefits of elevated CO(2), raising plant nitrogen pools will be necessary as part of maintaining an optimal C/N balance. In this review, we discuss potential causes for the stagnation in yield increases under elevated CO(2) levels and explore possibilities to overcome this limitation by improved photosynthetic capacity and enhanced nitrogen use efficiency. Opportunities of engineering nitrogen uptake, assimilatory, and responsive genes are also discussed that could ensure optimal nitrogen allocation toward expanding source and sink tissues. This might avert photosynthetic acclimation partially or completely and drive for improved crop production under elevated CO(2) levels.

Dependency of global primary bioenergy crop potentials in 2050 on food systems, yields, biodiversity conservation and political stability.

PubMed

Erb, Karl-Heinz; Haberl, Helmut; Plutzar, Christoph

2012-08-01

The future bioenergy crop potential depends on (1) changes in the food system (food demand, agricultural technology), (2) political stability and investment security, (3) biodiversity conservation, (4) avoidance of long carbon payback times from deforestation, and (5) energy crop yields. Using a biophysical biomass-balance model, we analyze how these factors affect global primary bioenergy potentials in 2050. The model calculates biomass supply and demand balances for eleven world regions, eleven food categories, seven food crop types and two livestock categories, integrating agricultural forecasts and scenarios with a consistent global land use and NPP database. The TREND scenario results in a global primary bioenergy potential of 77 EJ/yr, alternative assumptions on food-system changes result in a range of 26-141 EJ/yr. Exclusion of areas for biodiversity conservation and inaccessible land in failed states reduces the bioenergy potential by up to 45%. Optimistic assumptions on future energy crop yields increase the potential by up to 48%, while pessimistic assumptions lower the potential by 26%. We conclude that the design of sustainable bioenergy crop production policies needs to resolve difficult trade-offs such as food vs. energy supply, renewable energy vs. biodiversity conservation or yield growth vs. reduction of environmental problems of intensive agriculture.

Dependency of global primary bioenergy crop potentials in 2050 on food systems, yields, biodiversity conservation and political stability

PubMed Central

Erb, Karl-Heinz; Haberl, Helmut; Plutzar, Christoph

2012-01-01

The future bioenergy crop potential depends on (1) changes in the food system (food demand, agricultural technology), (2) political stability and investment security, (3) biodiversity conservation, (4) avoidance of long carbon payback times from deforestation, and (5) energy crop yields. Using a biophysical biomass-balance model, we analyze how these factors affect global primary bioenergy potentials in 2050. The model calculates biomass supply and demand balances for eleven world regions, eleven food categories, seven food crop types and two livestock categories, integrating agricultural forecasts and scenarios with a consistent global land use and NPP database. The TREND scenario results in a global primary bioenergy potential of 77 EJ/yr, alternative assumptions on food-system changes result in a range of 26–141 EJ/yr. Exclusion of areas for biodiversity conservation and inaccessible land in failed states reduces the bioenergy potential by up to 45%. Optimistic assumptions on future energy crop yields increase the potential by up to 48%, while pessimistic assumptions lower the potential by 26%. We conclude that the design of sustainable bioenergy crop production policies needs to resolve difficult trade-offs such as food vs. energy supply, renewable energy vs. biodiversity conservation or yield growth vs. reduction of environmental problems of intensive agriculture. PMID:23576836

Modelling predicts that tolerance to drought during reproductive development will be required for high yield potential and stability of wheat in Europe

NASA Astrophysics Data System (ADS)

Semenov, Mikhail A.; Stratonovitch, Pierre; Paul, Matthew J.

2017-04-01

Short periods of extreme weather, such as a spell of high temperature or drought during a sensitive stage of development, could result in substantial yield losses due to reduction in grain number and grain size. In a modelling study (Stratonovitch & Semenov 2015), heat tolerance around flowering in wheat was identified as a key trait for increased yield potential in Europe under climate change. Ji et all (Ji et al. 2010) demonstrated cultivar specific responses of yield to drought stress around flowering in wheat. They hypothesised that carbohydrate supply to anthers may be the key in maintaining pollen fertility and grain number in wheat. It was shown in (Nuccio et al. 2015) that genetically modified varieties of maize that increase the concentration of sucrose in ear spikelets, performed better under non-drought and drought conditions in field experiments. The objective of this modelling study was to assess potential benefits of tolerance to drought during reproductive development for wheat yield potential and yield stability across Europe. We used the Sirius wheat model to optimise wheat ideotypes for 2050 (HadGEM2, RCP8.5) climate scenarios at selected European sites. Eight cultivar parameters were optimised to maximise mean yields, including parameters controlling phenology, canopy growth and water limitation. At those sites where water could be limited, ideotypes sensitive to drought produced substantially lower mean yields and higher yield variability compare with tolerant ideotypes. Therefore, tolerance to drought during reproductive development is likely to be required for wheat cultivars optimised for the future climate in Europe in order to achieve high yield potential and yield stability.

Heat tolerance around flowering in wheat identified as a key trait for increased yield potential in Europe under climate change

PubMed Central

Stratonovitch, Pierre; Semenov, Mikhail A.

2015-01-01

To deliver food security for the 9 billon population in 2050, a 70% increase in world food supply will be required. Projected climatic and environmental changes emphasize the need for breeding strategies that delivers both a substantial increase in yield potential and resilience to extreme weather events such as heat waves, late frost, and drought. Heat stress around sensitive stages of wheat development has been identified as a possible threat to wheat production in Europe. However, no estimates have been made to assess yield losses due to increased frequency and magnitude of heat stress under climate change. Using existing experimental data, the Sirius wheat model was refined by incorporating the effects of extreme temperature during flowering and grain filling on accelerated leaf senescence, grain number, and grain weight. This allowed us, for the first time, to quantify yield losses resulting from heat stress under climate change. The model was used to optimize wheat ideotypes for CMIP5-based climate scenarios for 2050 at six sites in Europe with diverse climates. The yield potential for heat-tolerant ideotypes can be substantially increased in the future (e.g. by 80% at Seville, 100% at Debrecen) compared with the current cultivars by selecting an optimal combination of wheat traits, e.g. optimal phenology and extended duration of grain filling. However, at two sites, Seville and Debrecen, the grain yields of heat-sensitive ideotypes were substantially lower (by 54% and 16%) and more variable compared with heat-tolerant ideotypes, because the extended grain filling required for the increased yield potential was in conflict with episodes of high temperature during flowering and grain filling. Despite much earlier flowering at these sites, the risk of heat stress affecting yields of heat-sensitive ideotypes remained high. Therefore, heat tolerance in wheat is likely to become a key trait for increased yield potential and yield stability in southern Europe in the

Hydrogen bonding and interparticle forces in platelet alpha-Al2O3 dispersions: yield stress and zeta potential.

PubMed

Khoo, Kay-Sen; Teh, E-Jen; Leong, Yee-Kwong; Ong, Ban Choon

2009-04-09

Adsorbed phosphate on smooth platelet alpha-Al2O3 particles at saturation surface coverage gives rise to strong interparticle attractive forces in dispersion. The maximum yield stress at the point of zero charge was increased by 2-fold. This was attributed to a high density of intermolecular hydrogen bonding between the adsorbed phosphate layers of the interacting particles. Adsorbed citrate at saturation surface coverage, however, reduced the maximum yield stress by 50%. It adsorbed to form a very effective steric barrier as intramolecular hydrogen bonding between -OH and the free terminal carboxylic group prevented strong interactions with other adsorbed citrate molecules residing on the second interacting particle. This steric barrier kept the interacting platelet particles further apart, thereby weakening the van der Waals attraction. The platelet alpha-Al2O3 dispersions were flocculated at all pH level. These dispersions displayed a maximum yield stress at the point of zero zeta potential at the pH approximately 8.0. They also obeyed the yield stress-DLVO force model as characterized by a linear decrease in the yield stress with the square of the zeta potential.

The potential for using canopy spectral reflectance as an indirect selection tool for yield improvement in winter wheat

NASA Astrophysics Data System (ADS)

Prasad, Bishwajit

establish any trait as an efficient indirect selection tool, the water based SRI (especially NWI-3 and NWI-4) have the potential to complement the classical breeding effort for selecting genotypes with higher yield potential in a winter wheat breeding program.

Looking for Water in the Woods: Quantifying the Potential for Forest Management to Increase Regional Water Yield

NASA Astrophysics Data System (ADS)

Acharya, S.; Kaplan, D. A.; Mclaughlin, D. L.; Cohen, M. J.

2014-12-01

Water scarcity presents a crucial challenge for water resource managers charged with maintaining hydrologic resources for domestic, industrial, and agricultural use while protecting natural systems. Forest lands are critical to the functioning of the hydrologic cycle in many watersheds, affecting the quantity, quality, and timing of water delivered to surface and groundwater systems. While the hydrologic impacts of forest growth and removal have been shown to be substantial in watersheds around the globe, data and models connecting forest management to water use and regional hydrology are generally lacking. We propose that water-focused forest management has the potential to deliver a "new" source of water to surface and groundwater resources. To test this hypothesis, we developed a statistical model of water yield in southeastern US pine stands as a function of forest stand structure and ecosystem water use. Model results suggest a potential increase in water yield of up to 64% for pine stands managed at lower basal areas relative to those managed according to standard silvicultural practices. At the watershed scale, the magnitude of this potential water yield enhancement is driven by existing land use and forest management; evaluated for a large watershed in NE Florida, this potential increase is in excess of 200 million gallons per day (equivalent to 20% of the anthropogenic water use in the watershed). While useful for exploration, our statistical model also highlighted critical sources of uncertainty, including the effects of climatic variation, between-site variability, water use in young pine stands, and prescribed fire. Thus, in ongoing work we are comparing the effects of specific land management actions (e.g., thinning, clearcutting, and fire) on water yield across a gradient of environmental conditions (soil type, aquifer confinement, and climate) using a novel combination of in-situ soil moisture and groundwater monitoring. These data are being used to

Photosensitized electron transport across lipid vesicle walls: Enhancement of quantum yield by ionophores and transmembrane potentials

PubMed Central

Laane, Colja; Ford, William E.; Otvos, John W.; Calvin, Melvin

1981-01-01

The photosensitized reduction of heptylviologen in the bulk aqueous phase of phosphatidylcholine vesicles containing EDTA inside and a membrane-bound tris(2,2′-bipyridine)ruthenium(2+) derivative is enhanced by a factor of 6.5 by the addition of valinomycin in the presence of K+. A 3-fold stimulation by gramicidin and carbonyl cyanide m-chlorophenylhydrazone is observed. The results suggest that, under these conditions, the rate of photoinduced electron transfer across vesicle walls in the absence of ion carriers is limited by cotransport of cations. The rate of electron transfer across vesicle walls could be influenced further by generating transmembrane potentials with K+ gradients in the presence of valinomycin. When vesicles are made with transmembrane potentials, interior more negative, the quantum yield of heptylviologen reduction is doubled, and, conversely, when vesicles are made with transmembrane potentials, interior more positive, the quantum yield is decreased and approaches the value found in the absence of valinomycin. PMID:16593002

Estimating the potential refolding yield of recombinant proteins expressed as inclusion bodies.

PubMed

Ho, Jason G S; Middelberg, Anton P J

2004-09-05

Recombinant protein production in bacteria is efficient except that insoluble inclusion bodies form when some gene sequences are expressed. Such proteins must undergo renaturation, which is an inefficient process due to protein aggregation on dilution from concentrated denaturant. In this study, the protein-protein interactions of eight distinct inclusion-body proteins are quantified, in different solution conditions, by measurement of protein second virial coefficients (SVCs). Protein solubility is shown to decrease as the SVC is reduced (i.e., as protein interactions become more attractive). Plots of SVC versus denaturant concentration demonstrate two clear groupings of proteins: a more aggregative group and a group having higher SVC and better solubility. A correlation of the measured SVC with protein molecular weight and hydropathicity, that is able to predict which group each of the eight proteins falls into, is presented. The inclusion of additives known to inhibit aggregation during renaturation improves solubility and increases the SVC of both protein groups. Furthermore, an estimate of maximum refolding yield (or solubility) using high-performance liquid chromatography was obtained for each protein tested, under different environmental conditions, enabling a relationship between "yield" and SVC to be demonstrated. Combined, the results enable an approximate estimation of the maximum refolding yield that is attainable for each of the eight proteins examined, under a selected chemical environment. Although the correlations must be tested with a far larger set of protein sequences, this work represents a significant move beyond empirical approaches for optimizing renaturation conditions. The approach moves toward the ideal of predicting maximum refolding yield using simple bioinformatic metrics that can be estimated from the gene sequence. Such a capability could potentially "screen," in silico, those sequences suitable for expression in bacteria from those

Estimating the potential intensification of global grazing systems based on climate adjusted yield gap analysis

NASA Astrophysics Data System (ADS)

Sheehan, J. J.

2016-12-01

We report here a first-of-its-kind analysis of the potential for intensification of global grazing systems. Intensification is calculated using the statistical yield gap methodology developed previously by others (Mueller et al 2012 and Licker et al 2010) for global crop systems. Yield gaps are estimated by binning global pasture land area into 100 equal area sized bins of similar climate (defined by ranges of rainfall and growing degree days). Within each bin, grid cells of pastureland are ranked from lowest to highest productivity. The global intensification potential is defined as the sum of global production across all bins at a given percentile ranking (e.g. performance at the 90th percentile) divided by the total current global production. The previous yield gap studies focused on crop systems because productivity data on these systems is readily available. Nevertheless, global crop land represents only one-third of total global agricultural land, while pasture systems account for the remaining two-thirds. Thus, it is critical to conduct the same kind of analysis on what is the largest human use of land on the planet—pasture systems. In 2013, Herrero et al announced the completion of a geospatial data set that augmented the animal census data with data and modeling about production systems and overall food productivity (Herrero et al, PNAS 2013). With this data set, it is now possible to apply yield gap analysis to global pasture systems. We used the Herrero et al data set to evaluate yield gaps for meat and milk production from pasture based systems for cattle, sheep and goats. The figure included with this abstract shows the intensification potential for kcal per hectare per year of meat and milk from global cattle, sheep and goats as a function of increasing levels of performance. Performance is measured as the productivity achieved at a given ranked percentile within each bin.We find that if all pasture land were raised to their 90th percentile of

Bioinformatics evidence for the transfer of mycosporine-like amino acid core (4-deoxygadusol) synthesizing gene from cyanobacteria to dinoflagellates and an attempt to mutate the same gene (YP_324358) in Anabaena variabilis PCC 7937.

PubMed

Singh, Shailendra P; Häder, Donat-P; Sinha, Rajeshwar P

2012-06-01

We have identified a homologue of 4-deoxygadusol (core of mycosporine-like amino acids) synthesizing gene (ZP_05036788) from Synechococcus sp. PCC 7335 that was found to have additional functionally unknown N-terminal domain similar to homologues from dinoflagellates based on the ClustalW analysis. Phylogenetic analysis revealed that Synechococcus sp. (ZP_05036788) makes a clade together with dinoflagellates and was closest to the Oxyrrhis marina. This study shows for the first time that N-terminal additional sequences that possess upstream plastid targeting sequence in Heterocapsa triquetra and Karlodinium micrum were already evolved in cyanobacteria, and plastid targeting sequence were evolved later in dinoflagellates after divergence from chloroplast lacking Oxyrrhis marina. Thus, MAAs synthesizing genes were transferred from cyanobacteria to dinoflagellates and possibly Synechococcus sp. PCC 7335 acted as a donor during lateral gene transfer event. In addition, we also tried to mutate 4-deoxygadusol synthesizing gene (YP_324358) of Anabaena variabilis PCC 7937 by homologous recombination, however, all approaches to get complete segregation of the mutants from the wild-type were unsuccessful, showing the essentiality of YP_324358 for A. variabilis PCC 7937. Copyright © 2012 Elsevier B.V. All rights reserved.

Physiological Traits Associated with Wheat Yield Potential and Performance under Water-Stress in a Mediterranean Environment

PubMed Central

del Pozo, Alejandro; Yáñez, Alejandra; Matus, Iván A.; Tapia, Gerardo; Castillo, Dalma; Sanchez-Jardón, Laura; Araus, José L.

2016-01-01

Different physiological traits have been proposed as key traits associated with yield potential as well as performance under water stress. The aim of this paper is to examine the genotypic variability of leaf chlorophyll, stem water-soluble carbohydrate content and carbon isotope discrimination (Δ13C), and their relationship with grain yield (GY) and other agronomical traits, under contrasting water conditions in a Mediterranean environment. The study was performed on a large collection of 384 wheat genotypes grown under water stress (WS, rainfed), mild water stress (MWS, deficit irrigation), and full irrigation (FI). The average GY of two growing seasons was 2.4, 4.8, and 8.9 Mg ha−1 under WS, MWS, and FI, respectively. Chlorophyll content at anthesis was positively correlated with GY (except under FI in 2011) and the agronomical components kernels per spike (KS) and thousand kernel weight (TKW). The WSC content at anthesis (WSCCa) was negatively correlated with spikes per square meter (SM2), but positively correlated with KS and TKW under WS and FI conditions. As a consequence, the relationships between WSCCa with GY were low or not significant. Therefore, selecting for high stem WSC would not necessary lead to genotypes of GY potential. The relationship between Δ13C and GY was positive under FI and MWS but negative under severe WS (in 2011), indicating higher water use under yield potential and MWS conditions. PMID:27458470

Physiological Traits Associated with Wheat Yield Potential and Performance under Water-Stress in a Mediterranean Environment.

PubMed

Del Pozo, Alejandro; Yáñez, Alejandra; Matus, Iván A; Tapia, Gerardo; Castillo, Dalma; Sanchez-Jardón, Laura; Araus, José L

2016-01-01

Different physiological traits have been proposed as key traits associated with yield potential as well as performance under water stress. The aim of this paper is to examine the genotypic variability of leaf chlorophyll, stem water-soluble carbohydrate content and carbon isotope discrimination (Δ(13)C), and their relationship with grain yield (GY) and other agronomical traits, under contrasting water conditions in a Mediterranean environment. The study was performed on a large collection of 384 wheat genotypes grown under water stress (WS, rainfed), mild water stress (MWS, deficit irrigation), and full irrigation (FI). The average GY of two growing seasons was 2.4, 4.8, and 8.9 Mg ha(-1) under WS, MWS, and FI, respectively. Chlorophyll content at anthesis was positively correlated with GY (except under FI in 2011) and the agronomical components kernels per spike (KS) and thousand kernel weight (TKW). The WSC content at anthesis (WSCCa) was negatively correlated with spikes per square meter (SM2), but positively correlated with KS and TKW under WS and FI conditions. As a consequence, the relationships between WSCCa with GY were low or not significant. Therefore, selecting for high stem WSC would not necessary lead to genotypes of GY potential. The relationship between Δ(13)C and GY was positive under FI and MWS but negative under severe WS (in 2011), indicating higher water use under yield potential and MWS conditions.

Dakota Diamond: An exceptionally high yielding, cold chipping potato cultivar with long-term storage potential

USDA-ARS?s Scientific Manuscript database

Dakota Diamond (ND5822C-7) is a medium to late maturing cultivar with uniformly sized tubers and very high yield potential. It resulted from the cross of ND4103-2 and “Dakota Pearl”. Dakota Diamond is comprised of approximately 23.3% wild potato species germplasm. It combines the characteristics ...

Land Use, Yield and Quality Changes of Minor Field Crops: Is There Superseded Potential to Be Reinvented in Northern Europe?

PubMed

Peltonen-Sainio, Pirjo; Jauhiainen, Lauri; Lehtonen, Heikki

2016-01-01

Diversification of agriculture was one of the strengthened aims of the greening payment of European Agricultural Policy (CAP) as diversification provides numerous ecosystems services compared to cereal-intensive crop rotations. This study focuses on current minor crops in Finland that have potential for expanded production and considers changes in their cropping areas, yield trends, breeding gains, roles in crop rotations and potential for improving resilience. Long-term datasets of Natural Resources Institute Finland and farmers' land use data from the Agency of Rural Affairs were used to analyze the above-mentioned trends and changes. The role of minor crops in rotations declined when early and late CAP periods were compared and that of cereal monocultures strengthened. Genetic yield potentials of minor crops have increased as also genetic improvements in quality traits, although some typical trade-offs with improved yields have also appeared. However, the gap between potential and attained yields has expanded, depending on the minor crop, as national yield trends have either stagnated or declined. When comparing genetic improvements of minor crops to those of the emerging major crop, spring wheat, breeding achievements in minor crops were lower. It was evident that the current agricultural policies in the prevailing market and the price environment have not encouraged cultivation of minor crops but further strengthened the role of cereal monocultures. We suggest optimization of agricultural land use, which is a core element of sustainable intensification, as a future means to couple long-term environmental sustainability with better success in economic profitability and social acceptability. This calls for development of effective policy instruments to support farmer's diversification actions.

Land Use, Yield and Quality Changes of Minor Field Crops: Is There Superseded Potential to Be Reinvented in Northern Europe?

PubMed Central

Peltonen-Sainio, Pirjo; Jauhiainen, Lauri; Lehtonen, Heikki

2016-01-01

Diversification of agriculture was one of the strengthened aims of the greening payment of European Agricultural Policy (CAP) as diversification provides numerous ecosystems services compared to cereal-intensive crop rotations. This study focuses on current minor crops in Finland that have potential for expanded production and considers changes in their cropping areas, yield trends, breeding gains, roles in crop rotations and potential for improving resilience. Long-term datasets of Natural Resources Institute Finland and farmers’ land use data from the Agency of Rural Affairs were used to analyze the above-mentioned trends and changes. The role of minor crops in rotations declined when early and late CAP periods were compared and that of cereal monocultures strengthened. Genetic yield potentials of minor crops have increased as also genetic improvements in quality traits, although some typical trade-offs with improved yields have also appeared. However, the gap between potential and attained yields has expanded, depending on the minor crop, as national yield trends have either stagnated or declined. When comparing genetic improvements of minor crops to those of the emerging major crop, spring wheat, breeding achievements in minor crops were lower. It was evident that the current agricultural policies in the prevailing market and the price environment have not encouraged cultivation of minor crops but further strengthened the role of cereal monocultures. We suggest optimization of agricultural land use, which is a core element of sustainable intensification, as a future means to couple long-term environmental sustainability with better success in economic profitability and social acceptability. This calls for development of effective policy instruments to support farmer’s diversification actions. PMID:27870865

Quality of white cabbage yield and potential risk of ground water nitrogen pollution, as affected by nitrogen fertilisation and irrigation practices.

PubMed

Maršić, Nina Kacjan; Sturm, Martina; Zupanc, Vesna; Lojen, Sonja; Pintar, Marina

2012-01-15

The effect of different fertilisation (broadcast solid NPK application and fertigation with water-soluble fertiliser) and irrigation practices (sprinkler and drip irrigation) on yield, the nitrate content in cabbage (Brassica oleracea var. capitata L.) and the cabbage N uptake was detected, in order to assess the potential risk for N losses, by cultivation on sandy-loam soil. The N rate applied on the plots was 200 kg N ha(-1). The highest yield (93 t ha(-1)) and nitrate content (1256 mg kg(-1) DW) were found with treatments using broadcast fertilisation and sprinkler irrigation. On those plots the negative N balance (-30 kg N ha(-1)) was recorded, which comes mainly from the highest crop N uptake (234 kg N ha(-1)) indicating the lowest potential for N losses. In terms of yield quality and the potential risk for N losses, broadcast fertilisation combined with sprinkler irrigation proved to be the most effective combination among the tested practices under the given experimental conditions. The importance of adequate irrigation is also evident, namely in plots on which 50% drip irrigation was applied, the lowest yield was detected and according to the positive N balance, a higher potential for N losses is expected. Copyright © 2011 Society of Chemical Industry.

Potential water yield response following clearcut harvesting on north and south slopes in northern Idaho

Treesearch

Richard G. Cline; Harold F. Haupt; Gaylon S. Campbell

1977-01-01

The hydrologic response of small clearcuts on north and south slopes in northern Idaho was investigated. On the north slope, substantial gains (27 to 35 cm) in potential water yield per year resulted from (a) removal of transpiring surfaces associated with plant cover, (b) elimination of snow interception by a closed-canopied forest, and (C) delayed reoccupation of the...

Quantifying yield gaps in wheat production in Russia

NASA Astrophysics Data System (ADS)

Schierhorn, Florian; Faramarzi, Monireh; Prishchepov, Alexander V.; Koch, Friedrich J.; Müller, Daniel

2014-08-01

Crop yields must increase substantially to meet the increasing demands for agricultural products. Crop yield increases are particularly important for Russia because low crop yields prevail across Russia’s widespread and fertile land resources. However, reliable data are lacking regarding the spatial distribution of potential yields in Russia, which can be used to determine yield gaps. We used a crop growth model to determine the yield potentials and yield gaps of winter and spring wheat at the provincial level across European Russia. We modeled the annual yield potentials from 1995 to 2006 with optimal nitrogen supplies for both rainfed and irrigated conditions. Overall, the results suggest yield gaps of 1.51-2.10 t ha-1, or 44-52% of the yield potential under rainfed conditions. Under irrigated conditions, yield gaps of 3.14-3.30 t ha-1, or 62-63% of the yield potential, were observed. However, recurring droughts cause large fluctuations in yield potentials under rainfed conditions, even when the nitrogen supply is optimal, particularly in the highly fertile black soil areas of southern European Russia. The highest yield gaps (up to 4 t ha-1) under irrigated conditions were detected in the steppe areas in southeastern European Russia along the border of Kazakhstan. Improving the nutrient and water supply and using crop breeds that are adapted to the frequent drought conditions are important for reducing yield gaps in European Russia. Our regional assessment helps inform policy and agricultural investors and prioritize research that aims to increase crop production in this important region for global agricultural markets.

Photosensitized electron transfer processes in SiO2 colloids and sodium lauryl sulfate micellar systems: Correlation of quantum yields with interfacial surface potentials

PubMed Central

Laane, Colja; Willner, Itamar; Otvos, John W.; Calvin, Melvin

1981-01-01

The effectiveness of negatively charged colloidal SiO2 particles in controlling photosensitized electron transfer reactions has been studied and compared with that of the negatively charged sodium lauryl sulfate (NaLauSO4) micellar system. In particular, the photosensitized reduction of the zwitterionic electron acceptor propylviologen sulfonate (PVS0) with tris(2,2′-bipyridinium)ruthenium(II) [Ru(bipy)32+] as the sensitizer and triethanolamine as the electron donor is found to have a quantum yield of 0.033 for formation of the radical anion (PVS[unk]) in the SiO2 colloid compared with 0.005 in the homogeneous system and 0.0086 in a NaLauSO4 micellar solution. The higher quantum yields obtained with the SiO2 colloidal system are attributed to substantial stabilization against back reaction of the intermediate photoproducts—i.e., Ru(bipy)33+ and PVS[unk]—by electrostatic repulsion of the reduced electron acceptor from the negatively charged particle surface. The binding properties of the SiO2 particles and NaLauSO4 micelles were investigated by flow dialysis. The results show that the sensitizer binds to both interfaces and that the SiO2 interface is characterized by a much higher surface potential than the micellar interface (≈-170 mV vs. -85 mV). The effect of ionic strength on the surface potential was estimated from the Gouy-Chapman theory, and the measured quantum yields of photosensitized electron transfer were correlated with surface potential at different ionic strengths. This correlation shows that the quantum yield is not affected by surface potentials smaller than ≈-40 mV. At larger potentials, the quantum yield increases rapidly. The quantum yield obtained in the micellar system at different strengths fits nicely on the correlation curve for the colloid SiO2 system. These results indicate that the surface potential is the dominant factor in the quantum yield improvement for PVS0 reduction. PMID:16593095

CERES-Maize model-based simulation of climate change impacts on maize yields and potential adaptive measures in Heilongjiang Province, China.

PubMed

Lin, Yumei; Wu, Wenxiang; Ge, Quansheng

2015-11-01

Climate change would cause negative impacts on future agricultural production and food security. Adaptive measures should be taken to mitigate the adverse effects. The objectives of this study were to simulate the potential effects of climate change on maize yields in Heilongjiang Province and to evaluate two selected typical household-level autonomous adaptive measures (cultivar changes and planting time adjustments) for mitigating the risks of climate change based on the CERES-Maize model. The results showed that flowering duration and maturity duration of maize would be shortened in the future climate and thus maize yield would reduce by 11-46% during 2011-2099 relative to 1981-2010. Increased CO2 concentration would not benefit maize production significantly. However, substituting local cultivars with later-maturing ones and delaying the planting date could increase yields as the climate changes. The results provide insight regarding the likely impacts of climate change on maize yields and the efficacy of selected adaptive measures by presenting evidence-based implications and mitigation strategies for the potential negative impacts of future climate change. © 2014 Society of Chemical Industry.

Can Bangladesh produce enough cereals to meet future demand?

PubMed

Timsina, J; Wolf, J; Guilpart, N; van Bussel, L G J; Grassini, P; van Wart, J; Hossain, A; Rashid, H; Islam, S; van Ittersum, M K

2018-06-01

Bangladesh faces huge challenges in achieving food security due to its high population, diet changes, and limited room for expanding cropland and cropping intensity. The objective of this study is to assess the degree to which Bangladesh can be self-sufficient in terms of domestic maize, rice and wheat production by the years 2030 and 2050 by closing the existing gap (Yg) between yield potential (Yp) and actual farm yield (Ya), accounting for possible changes in cropland area. Yield potential and yield gaps were calculated for the three crops using well-validated crop models and site-specific weather, management and soil data, and upscaled to the whole country. We assessed potential grain production in the years 2030 and 2050 for six land use change scenarios (general decrease in arable land; declining ground water tables in the north; cropping of fallow areas in the south; effect of sea level rise; increased cropping intensity; and larger share of cash crops) and three levels of Yg closure (1: no yield increase; 2: Yg closure at a level equivalent to 50% (50% Yg closure); 3: Yg closure to a level of 85% of Yp (irrigated crops) and 80% of water-limited yield potential or Yw (rainfed crops) (full Yg closure)). In addition, changes in demand with low and high population growth rates, and substitution of rice by maize in future diets were also examined. Total aggregated demand of the three cereals (in milled rice equivalents) in 2030 and 2050, based on the UN median population variant, is projected to be 21 and 24% higher than in 2010. Current Yg represent 50% (irrigated rice), 48-63% (rainfed rice), 49% (irrigated wheat), 40% (rainfed wheat), 46% (irrigated maize), and 44% (rainfed maize) of their Yp or Yw. With 50% Yg closure and for various land use changes, self-sufficiency ratio will be > 1 for rice in 2030 and about one in 2050 but well below one for maize and wheat in both 2030 and 2050. With full Yg closure, self-sufficiency ratios will be well above one for

Management of soybean oil refinery wastes through recycling them for producing biosurfactant using Pseudomonas aeruginosa MR01.

PubMed

Partovi, Maryam; Lotfabad, Tayebe Bagheri; Roostaazad, Reza; Bahmaei, Manochehr; Tayyebi, Shokoufe

2013-06-01

Biosurfactant production through a fermentation process involving the biodegradation of soybean oil refining wastes was studied. Pseudomonas aeruginosa MR01 was able to produce extracellular biosurfactant when it was cultured in three soybean oil refinement wastes; acid oil, deodorizer distillate and soapstock, at different carbon to nitrogen ratios. Subsequent fermentation kinetics in the three types of waste culture were also investigated and compared with kinetic behavior in soybean oil medium. Biodegradation of wastes, biosurfactant production, biomass growth, nitrate consumption and the number of colony forming units were detected in four proposed media, at specified time intervals. Unexpectedly, wastes could stimulate the biodegradation activity of MR01 bacterial cells and thus biosurfactant synthesis beyond that of the refined soybean oil. This is evident from higher yields of biodegradation and production, as revealed in the waste cultures (Ydeg|(Soybean oil) = 53.9 % < Ydeg|(wastes) and YP/S|(wastes) > YP/S|(Soybean oil) = 0.31 g g(-1), respectively). Although production yields were approximately the same in the three waste cultures (YP/S|(wastes) =/~ 0.5 g g(-1)), microbial activity resulted in higher yields of biodegradation (96.5 ± 1.13 %), maximum specific growth rate (μ max = 0.26 ± 0.02 h(-1)), and biosurfactant purity (89.6 %) with a productivity of 14.55 ± 1.10 g l(-1), during the bioconversion of soapstock into biosurfactant. Consequently, applying soybean oil soapstock as a substrate for the production of biosurfactant with commercial value has the potential to provide a combination of economical production with environmental protection through the biosynthesis of an environmentally friendly (green) compound and reduction of waste load entering the environment. Moreover, this work inferred spectrophotometry as an easy method to detect rhamnolipids in the biosurfactant products.

Exploring the relationship between irrigation water requirements and potential yield in the Huang-Huai-Hai plain

NASA Astrophysics Data System (ADS)

Tang, Huaxiu; Zhan, Jinyan; Deng, Xiangzheng; Ma, Jinsong

2007-11-01

By using the GIS technologies, we interpolate the site-based meteorological data into climatic surface data, which are the main input parameters for the CropWat model, used to estimate the reference evapotranspiration (ET 0). And then by combining the ET 0 with the information on share of cultivated land decoded from the Landsat TM/ETM digital imagines covering the entire case study area, the Huang-Huai-Hai plain, we estimate the amount of irrigation water requirements (IWRs) in the years of 1991 and 2000. We then introduce the potential yield (PY) of cultivated land estimated from the Estimation Model for the Agricultural Productivity Potential (EMAPP) to explore the relationship between the IWRs and the PY . By conducting GIS-based spatial overlay analyses, we explore the positive correlation relationship between the IWRs and the PY of cultivated land. Finally, we conclude that the IWRs is now a constrain factor on the PY of cultivated land in the Huang-Huai-Hai plain in those areas with the irrigation water constrains. The result has offered a scientific basis for the decision makings in the exploitation and utilization of resources and energy as well as the land use planning, protection of the potential yields and the managements of irrigation water at the regional level.

Using Satellite Data to Identify the Causes of and Potential Solutions for Yield Gaps in India's Wheat Belt

NASA Astrophysics Data System (ADS)

Jain, M.; Singh, B.; Srivastava, A.; Malik, R. K.; McDonald, A.; Lobell, D. B.

2017-12-01

Food security will be increasingly challenged by climate change, natural resource degradation, and population growth. Wheat yields, in particular, have already stagnated in many regions and will be further affected by warming temperatures. Despite these challenges, wheat yields can be increased by improving management practices in regions with existing yield gaps. We present two studies that are using satellite data to better understand the factors contributing to yield gaps and potential interventions to close yield gaps in India's main wheat belt, the Indo-Gangetic Plains (IGP). To identify the magnitude and causes of current yield gaps, we produced 30 meter resolution yield maps from 2001 to 2015 using Landsat sallite data and a new method that translates satellite vegetation indices to yield estimates using crop model simulations, bypassing the need for ground calibration data. This is one of the first attempts to apply this method to a smallholder agriculture system, where ground calibration data are rarely available. We find that yields can be increased by 11% on average and up to 32% in the eastern IGP by improving management to current best practices within a given district. Additionally, if current best practices from the highest-yielding state of Punjab are implemented in the eastern IGP, yields could increase by almost 110%. Considering the factors that most influence yields, later sow dates and warmer temperatures are most associated with low yields across the IGP. This suggests that strategies to reduce the negative effects of heat stress, like earlier sowing and planting heat-tolerant wheat varieties, are critical to increasing wheat yields in this globally-important agricultural region. We also apply this method to high-resolution micro-satellite data (< 5 m) to map field and sub-field level yields across villages in Bihar in the eastern IGP. Using these data, we assess the impacts of a new fertilizer spreader technology and identify whether

Potential impacts of agricultural drought on crop yield variability under a changing climate in Texas

NASA Astrophysics Data System (ADS)

Lee, K.; Leng, G.; Huang, M.; Sheffield, J.; Zhao, G.; Gao, H.

2017-12-01

Texas has the largest farm area in the U.S, and its revenue from crop production ranks third overall. With the changing climate, hydrological extremes such as droughts are becoming more frequent and intensified, causing significant yield reduction in rainfed agricultural systems. The objective of this study is to investigate the potential impacts of agricultural drought on crop yields (corn, sorghum, and wheat) under a changing climate in Texas. The Variable Infiltration Capacity (VIC) model, which is calibrated and validated over 10 major Texas river basins during the historical period, is employed in this study.The model is forced by a set of statistically downscaled climate projections from Coupled Model Intercomparison Project Phase 5 (CMIP5) model ensembles at a spatial resolution of 1/8°. The CMIP5 projections contain four Representative Concentration Pathways (RCP) that represent different greenhouse gas concentration (4.5 and 8.5 w/m2 are selected in this study). To carry out the analysis, VIC simulations from 1950 to 2099 are first analyzed to investigate how the frequency and severity of agricultural droughts will be altered in Texas (under a changing climate). Second, future crop yields are projected using a statistical crop model. Third, the effects of agricultural drought on crop yields are quantitatively analyzed. The results are expected to contribute to future water resources planning, with a goal of mitigating the negative impacts of future droughts on agricultural production in Texas.

Climatic and technological ceilings for Chinese rice stagnation based on yield gaps and yield trend pattern analysis.

PubMed

Zhang, Tianyi; Yang, Xiaoguang; Wang, Hesong; Li, Yong; Ye, Qing

2014-04-01

Climatic or technological ceilings could cause yield stagnation. Thus, identifying the principal reasons for yield stagnation within the context of the local climate and socio-economic conditions are essential for informing regional agricultural policies. In this study, we identified the climatic and technological ceilings for seven rice-production regions in China based on yield gaps and on a yield trend pattern analysis for the period 1980-2010. The results indicate that 54.9% of the counties sampled experienced yield stagnation since the 1980. The potential yield ceilings in northern and eastern China decreased to a greater extent than in other regions due to the accompanying climate effects of increases in temperature and decreases in radiation. This may be associated with yield stagnation and halt occurring in approximately 49.8-57.0% of the sampled counties in these areas. South-western China exhibited a promising scope for yield improvement, showing the greatest yield gap (30.6%), whereas the yields were stagnant in 58.4% of the sampled counties. This finding suggests that efforts to overcome the technological ceiling must be given priority so that the available exploitable yield gap can be achieved. North-eastern China, however, represents a noteworthy exception. In the north-central area of this region, climate change has increased the yield potential ceiling, and this increase has been accompanied by the most rapid increase in actual yield: 1.02 ton ha(-1) per decade. Therefore, north-eastern China shows a great potential for rice production, which is favoured by the current climate conditions and available technology level. Additional environmentally friendly economic incentives might be considered in this region. © 2013 John Wiley & Sons Ltd.

Cellulosic feedstock production on Conservation Reserve Program land: Potential yields and environmental effects

DOE PAGES

LeDuc, Stephen D.; Zhang, Xuesong; Clark, Christopher M.; ...

2016-02-26

Producing biofuel feedstocks on current agricultural land raises questions of a ‘food-vs.-fuel’ trade-off. The use of current or former Conservation Reserve Program (CRP) land offers an alternative; yet the volumes of ethanol that could be produced and the potential environmental impacts of such a policy are unclear. Here, we applied the Environmental Policy Integrated Climate model to a US Department of Agriculture database of over 200 000 CRP polygons in Iowa, USA, as a case study. We simulated yields and environmental impacts of growing three cellulosic biofuel feedstocks on CRP land: (i) an Alamo-variety switchgrass ( Panicum virgatum L.); (ii)more » a generalized mixture of C4 and C3 grasses; (iii) and no-till corn ( Zea mays L.) with residue removal. We simulated yields, soil erosion, and soil carbon (C) and nitrogen (N) stocks and fluxes. We found that although no-till corn with residue removal produced approximately 2.6–4.4 times more ethanol per area compared to switchgrass and the grass mixture, it also led to 3.9–4.5 times more erosion, 4.4–5.2 times more cumulative N loss, and a 10% reduction in total soil carbon as opposed to a 6–11% increase. Switchgrass resulted in the best environmental outcomes even when expressed on a per liter ethanol basis. Our results suggest planting no-till corn with residue removal should only be done on low slope soils to minimize environmental concerns. Altogether, this analysis provides additional information to policy makers on the potential outcome and effects of producing biofuel feedstocks on current or former conservation lands.« less

Impact of Climate Change on Potential, Attainable, and Actual Wheat Yield in Oklahoma

NASA Astrophysics Data System (ADS)

Dhakal, K.; Linde, E.; Kakani, V. G.; Alderman, P. D.; Brunson, D.; Ochsner, T. E.; Carver, B.

2017-12-01

Gradually developing climatic and weather anomalies due to increasing atmospheric greenhouse gases concentration can pose threat to farmers and resource managers. This study was aimed at investigating the effects of climate change on winter wheat (Triticum aestivum L.) under the Representative Concentration Pathways 6.0 and 8.5 using downscaled climate projections from different models and their ensembles. Daily data of maximum and minimum air temperature, rainfall, and solar radiation for, four General Circulation Models (MRIOC5, MRI-CGCM3, HadGEM2-ES, CSRIO-Mk3.6.0), ensemble of four models and ensemble of 17 GCMs, at 800 m resolution, were developed for two RCPs using Marksim. We describe a methodology for rapid synthesis of GCM-based, spatially explicit, high resolution future weather data inputs for the DSSAT crop model, for cropland area across wheat growing regions of Oklahoma for the future period 2040-2060. The potential impacts of climate change and variability on potential, attainable, and actual winter wheat yield in Oklahoma is discussed.

Nut crop yield records show that budbreak-based chilling requirements may not reflect yield decline chill thresholds

NASA Astrophysics Data System (ADS)

Pope, Katherine S.; Dose, Volker; Da Silva, David; Brown, Patrick H.; DeJong, Theodore M.

2015-06-01

Warming winters due to climate change may critically affect temperate tree species. Insufficiently cold winters are thought to result in fewer viable flower buds and the subsequent development of fewer fruits or nuts, decreasing the yield of an orchard or fecundity of a species. The best existing approximation for a threshold of sufficient cold accumulation, the "chilling requirement" of a species or variety, has been quantified by manipulating or modeling the conditions that result in dormant bud breaking. However, the physiological processes that affect budbreak are not the same as those that determine yield. This study sought to test whether budbreak-based chilling thresholds can reasonably approximate the thresholds that affect yield, particularly regarding the potential impacts of climate change on temperate tree crop yields. County-wide yield records for almond ( Prunus dulcis), pistachio ( Pistacia vera), and walnut ( Juglans regia) in the Central Valley of California were compared with 50 years of weather records. Bayesian nonparametric function estimation was used to model yield potentials at varying amounts of chill accumulation. In almonds, average yields occurred when chill accumulation was close to the budbreak-based chilling requirement. However, in the other two crops, pistachios and walnuts, the best previous estimate of the budbreak-based chilling requirements was 19-32 % higher than the chilling accumulations associated with average or above average yields. This research indicates that physiological processes beyond requirements for budbreak should be considered when estimating chill accumulation thresholds of yield decline and potential impacts of climate change.

A decade of precision agriculture impacts on grain yield and yield variation

USDA-ARS?s Scientific Manuscript database

Targeting management practices and inputs with precision agriculture has high potential to meet some of the grand challenges of sustainability in the coming century, including simultaneously improving crop yields and reducing environmental impacts. Although the potential is high, few studies have do...

Oil palm natural diversity and the potential for yield improvement

PubMed Central

Barcelos, Edson; Rios, Sara de Almeida; Cunha, Raimundo N. V.; Lopes, Ricardo; Motoike, Sérgio Y.; Babiychuk, Elena; Skirycz, Aleksandra; Kushnir, Sergei

2015-01-01

African oil palm has the highest productivity amongst cultivated oleaginous crops. Species can constitute a single crop capable to fulfill the growing global demand for vegetable oils, which is estimated to reach 240 million tons by 2050. Two types of vegetable oil are extracted from the palm fruit on commercial scale. The crude palm oil and kernel palm oil have different fatty acid profiles, which increases versatility of the crop in industrial applications. Plantations of the current varieties have economic life-span around 25–30 years and produce fruits around the year. Thus, predictable annual palm oil supply enables marketing plans and adjustments in line with the economic forecasts. Oil palm cultivation is one of the most profitable land uses in the humid tropics. Oil palm fruits are the richest plant source of pro-vitamin A and vitamin E. Hence, crop both alleviates poverty, and could provide a simple practical solution to eliminate global pro-vitamin A deficiency. Oil palm is a perennial, evergreen tree adapted to cultivation in biodiversity rich equatorial land areas. The growing demand for the palm oil threatens the future of the rain forests and has a large negative impact on biodiversity. Plant science faces three major challenges to make oil palm the key element of building the future sustainable world. The global average yield of 3.5 tons of oil per hectare (t) should be raised to the full yield potential estimated at 11–18t. The tree architecture must be changed to lower labor intensity and improve mechanization of the harvest. Oil composition should be tailored to the evolving needs of the food, oleochemical and fuel industries. The release of the oil palm reference genome sequence in 2013 was the key step toward this goal. The molecular bases of agronomically important traits can be and are beginning to be understood at the single base pair resolution, enabling gene-centered breeding and engineering of this remarkable crop. PMID:25870604

Oil palm natural diversity and the potential for yield improvement.

PubMed

Barcelos, Edson; Rios, Sara de Almeida; Cunha, Raimundo N V; Lopes, Ricardo; Motoike, Sérgio Y; Babiychuk, Elena; Skirycz, Aleksandra; Kushnir, Sergei

2015-01-01

African oil palm has the highest productivity amongst cultivated oleaginous crops. Species can constitute a single crop capable to fulfill the growing global demand for vegetable oils, which is estimated to reach 240 million tons by 2050. Two types of vegetable oil are extracted from the palm fruit on commercial scale. The crude palm oil and kernel palm oil have different fatty acid profiles, which increases versatility of the crop in industrial applications. Plantations of the current varieties have economic life-span around 25-30 years and produce fruits around the year. Thus, predictable annual palm oil supply enables marketing plans and adjustments in line with the economic forecasts. Oil palm cultivation is one of the most profitable land uses in the humid tropics. Oil palm fruits are the richest plant source of pro-vitamin A and vitamin E. Hence, crop both alleviates poverty, and could provide a simple practical solution to eliminate global pro-vitamin A deficiency. Oil palm is a perennial, evergreen tree adapted to cultivation in biodiversity rich equatorial land areas. The growing demand for the palm oil threatens the future of the rain forests and has a large negative impact on biodiversity. Plant science faces three major challenges to make oil palm the key element of building the future sustainable world. The global average yield of 3.5 tons of oil per hectare (t) should be raised to the full yield potential estimated at 11-18t. The tree architecture must be changed to lower labor intensity and improve mechanization of the harvest. Oil composition should be tailored to the evolving needs of the food, oleochemical and fuel industries. The release of the oil palm reference genome sequence in 2013 was the key step toward this goal. The molecular bases of agronomically important traits can be and are beginning to be understood at the single base pair resolution, enabling gene-centered breeding and engineering of this remarkable crop.

Does gang ripping hold the potential for higher clear cutting yields

Treesearch

Hiram Hallock; Pamela Giese

1980-01-01

Cutting yields from gang ripping hardwood lumber graded by the National Hardwood Lumber Association standard grades are determined using the technique of mathematical modeling. The lumber used is the same as that in an earlier mathematically modeled determination of cutting yields from traditional rough mill procedures. Mechanical cutting factors such as kerf, cutting...

A GIS-based model of potential groundwater yield zonation for a sandstone aquifer in the Juye Coalfield, Shangdong, China

NASA Astrophysics Data System (ADS)

Yin, Huiyong; Shi, Yongli; Niu, Huigong; Xie, Daolei; Wei, Jiuchuan; Lefticariu, Liliana; Xu, Shuanxiang

2018-02-01

Resolving the potential groundwater yield zonation of sandstone aquifers occurring at depths of several hundred meters has been an important and challenging objective of the hydrogeological research focused on preventing flood hazards in coal mines. Using accessible geological exploration data we put forward a method of predicting the spatial distribution of groundwater storage potential in sandstone aquifers from Permian-age coal deposits in Juye Coalfield, Shangdong, China. A Geological, Tectonic and Lithological Composition Index (GTLCI) model was created using the following parameters: sandstone depth and thickness, faults length density (FaLD), faults density (FaD), fault frequency density (FaFD), fault scale density (FaSD), variation coefficient of the slope (VCS) of the coal seam, intensity index of folds in horizontal direction (IIFoH), and lithological composition index (LCI). Each of these factors was subsequently divided into 5 classes. The analytic hierarchy process (AHP) and trapezoidal fuzzy number (TFN) method was applied to calculate the weight of the conditioning factor and their respective sub-classes. Groundwater yield potential contour map, which was initially constructed using the GTLCI values revealed four groundwater abundance zones. The map was further refined by taking into account hydrogeologic data collected during mining activities. The GTLCI model predictive success rate of 80% was explained by the limited number of boreholes available for validation. It is considered that the GTLCI model is effective at predicting zonation of groundwater yield in the sandstone aquifers from Permian- age coal deposits in Juye Coalfield, China.

Maximizing Amazonia's Ecosystem Services: Juggling the potential for carbon storage, agricultural yield and biodiversity in the Amazon

NASA Astrophysics Data System (ADS)

O'Connell, C. S.; Foley, J. A.; Gerber, J. S.; Polasky, S.

2011-12-01

The Amazon is not only an exceptionally biodiverse and carbon-rich tract of tropical forest, it is also a case study in land use change. Over the next forty years it will continue to experience pressure from an urbanizing and increasingly affluent populace: under a business-as-usual scenario, global cropland, pasture and biofuels systems will carry on expanding, while the Amazon's carbon storage potential will likely become another viable revenue source under REDD+. Balancing those competing land use pressures ought also take into account Amazonia's high - but heterogeneous - biodiversity. Knowing where Amazonia has opportunities to make efficient or optimal trade offs between carbon storage, agricultural production and biodiversity can allow policymakers to direct or influence LUC drivers. This analysis uses a spatially-explicit model that takes climate and management into account to quantify the potential agricultural yield of both the Amazon's most important agricultural commodities - sugar, soy and maize - as well as several that are going to come into increasing prominence, including palm oil. In addition, it maps the potential for carbon to be stored in forest biomass and relative species richness across Amazonia. We then compare carbon storage, agricultural yield and species richness and identify areas where efficient trade offs occur between food, carbon, and biodiversity - three critical ecosystem goods and services provided by the world's largest tropical forest.

Predicting paddlefish roe yields using an extension of the Beverton–Holt equilibrium yield-per-recruit model

USGS Publications Warehouse

Colvin, M.E.; Bettoli, Phillip William; Scholten, G.D.

2013-01-01

Equilibrium yield models predict the total biomass removed from an exploited stock; however, traditional yield models must be modified to simulate roe yields because a linear relationship between age (or length) and mature ovary weight does not typically exist. We extended the traditional Beverton-Holt equilibrium yield model to predict roe yields of Paddlefish Polyodon spathula in Kentucky Lake, Tennessee-Kentucky, as a function of varying conditional fishing mortality rates (10-70%), conditional natural mortality rates (cm; 9% and 18%), and four minimum size limits ranging from 864 to 1,016mm eye-to-fork length. These results were then compared to a biomass-based yield assessment. Analysis of roe yields indicated the potential for growth overfishing at lower exploitation rates and smaller minimum length limits than were suggested by the biomass-based assessment. Patterns of biomass and roe yields in relation to exploitation rates were similar regardless of the simulated value of cm, thus indicating that the results were insensitive to changes in cm. Our results also suggested that higher minimum length limits would increase roe yield and reduce the potential for growth overfishing and recruitment overfishing at the simulated cm values. Biomass-based equilibrium yield assessments are commonly used to assess the effects of harvest on other caviar-based fisheries; however, our analysis demonstrates that such assessments likely underestimate the probability and severity of growth overfishing when roe is targeted. Therefore, equilibrium roe yield-per-recruit models should also be considered to guide the management process for caviar-producing fish species.

Hemicellulosic Ethanol Production by Immobilized Wild Brazilian Yeast Scheffersomyces shehatae UFMG-HM 52.2: Effects of Cell Concentration and Stirring Rate.

PubMed

Antunes, F A F; Santos, J C; Chandel, A K; Milessi, T S S; Peres, G F D; da Silva, S S

2016-02-01

The use of sugarcane bagasse hemicellulosic hydrolysates presents an interesting alternative to second generation (2G) ethanol production. Techniques to enhance the fermentation process, e.g., the use of immobilized cells, is one of the key factors for efficient production. Here, the effect of two important parameters (cell concentration in immobilized system and stirring rate) on the 2G ethanol production using the wild Brazilian yeast S. shehatae UFMG-HM 52.2 immobilized in calcium alginate matrix are presented. A 2(2) full factorial design of experiments was carried out to evaluate the effect of cell concentrations in sodium alginate solution for immobilized bead production (3.0, 6.0, and 9.0 g/L) and stirring rate (150, 200, and 250 rpm) for 2G ethanol production. Statistical analysis showed that the use of both variables at low levels enhanced ethanol yield (YP/S). Under these process conditions, YP/S of 0.31 g/g and ethanol productivity (Qp) of 0.12 g/L h were achieved. Results showed the potential of this immobilized yeast in 2G ethanol production from C5 sugars and demonstrate the importance of adequate cell concentration in immobilized systems, a finding that stands to increase bioprocesses yields and productivity.

Metabolomic prediction of yield in hybrid rice.

PubMed

Xu, Shizhong; Xu, Yang; Gong, Liang; Zhang, Qifa

2016-10-01

Rice (Oryza sativa) provides a staple food source for more than 50% of the world's population. An increase in yield can significantly contribute to global food security. Hybrid breeding can potentially help to meet this goal because hybrid rice often shows a considerable increase in yield when compared with pure-bred cultivars. We recently developed a marker-guided prediction method for hybrid yield and showed a substantial increase in yield through genomic hybrid breeding. We now have transcriptomic and metabolomic data as potential resources for prediction. Using six prediction methods, including least absolute shrinkage and selection operator (LASSO), best linear unbiased prediction (BLUP), stochastic search variable selection, partial least squares, and support vector machines using the radial basis function and polynomial kernel function, we found that the predictability of hybrid yield can be further increased using these omic data. LASSO and BLUP are the most efficient methods for yield prediction. For high heritability traits, genomic data remain the most efficient predictors. When metabolomic data are used, the predictability of hybrid yield is almost doubled compared with genomic prediction. Of the 21 945 potential hybrids derived from 210 recombinant inbred lines, selection of the top 10 hybrids predicted from metabolites would lead to a ~30% increase in yield. We hypothesize that each metabolite represents a biologically built-in genetic network for yield; thus, using metabolites for prediction is equivalent to using information integrated from these hidden genetic networks for yield prediction. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

An adapted yield criterion for the evolution of subsequent yield surfaces

NASA Astrophysics Data System (ADS)

Küsters, N.; Brosius, A.

2017-09-01

In numerical analysis of sheet metal forming processes, the anisotropic material behaviour is often modelled with isotropic work hardening and an average Lankford coefficient. In contrast, experimental observations show an evolution of the Lankford coefficients, which can be associated with a yield surface change due to kinematic and distortional hardening. Commonly, extensive efforts are carried out to describe these phenomena. In this paper an isotropic material model based on the Yld2000-2d criterion is adapted with an evolving yield exponent in order to change the yield surface shape. The yield exponent is linked to the accumulative plastic strain. This change has the effect of a rotating yield surface normal. As the normal is directly related to the Lankford coefficient, the change can be used to model the evolution of the Lankford coefficient during yielding. The paper will focus on the numerical implementation of the adapted material model for the FE-code LS-Dyna, mpi-version R7.1.2-d. A recently introduced identification scheme [1] is used to obtain the parameters for the evolving yield surface and will be briefly described for the proposed model. The suitability for numerical analysis will be discussed for deep drawing processes in general. Efforts for material characterization and modelling will be compared to other common yield surface descriptions. Besides experimental efforts and achieved accuracy, the potential of flexibility in material models and the risk of ambiguity during identification are of major interest in this paper.

Nitrogen and tillage management affect corn cellulosic yield, composition, and ethanol potential

USDA-ARS?s Scientific Manuscript database

Corn (Zea mays L.) stover and cobs remaining after grain harvest can serve as a feedstock for cellulosic ethanol production. Field trials were conducted at two locations in Minnesota over three years to determine how corn cellulosic yield composition and ethanol yield are influenced by tillage syste...

Identifying seedling root architectural traits associated with yield and yield components in wheat.

PubMed

Xie, Quan; Fernando, Kurukulasuriya M C; Mayes, Sean; Sparkes, Debbie L

2017-05-01

Plant roots growing underground are critical for soil resource acquisition, anchorage and plant-environment interactions. In wheat ( Triticum aestivum ), however, the target root traits to improve yield potential still remain largely unknown. This study aimed to identify traits of seedling root system architecture (RSA) associated with yield and yield components in 226 recombinant inbred lines (RILs) derived from a cross between the bread wheat Triticum aestivum 'Forno' (small, wide root system) and spelt Triticum spelta 'Oberkulmer' (large, narrow root system). A 'pouch and wick' high-throughput phenotyping pipeline was used to determine the RSA traits of 13-day-old RIL seedlings. Two field experiments and one glasshouse experiment were carried out to investigate the yield, yield components and phenology, followed by identification of quantitative trait loci (QTLs). There was substantial variation in RSA traits between genotypes. Seminal root number and total root length were both positively associated with grains m -2 , grains per spike, above-ground biomass m -2 and grain yield. More seminal roots and longer total root length were also associated with delayed maturity and extended grain filling, likely to be a consequence of more grains being defined before anthesis. Additionally, the maximum width of the root system displayed positive relationships with spikes m -2 , grains m -2 and grain yield. Ten RILs selected for the longest total roots exhibited the same effects on yield and phenology as described above, compared with the ten lines with the shortest total roots. Genetic analysis revealed 38 QTLs for the RSA, and QTL coincidence between the root and yield traits was frequently observed, indicating tightly linked genes or pleiotropy, which concurs with the results of phenotypic correlation analysis. Based on the results from the Forno × Oberkulmer population, it is proposed that vigorous early root growth, particularly more seminal roots and longer total

Closing Yield Gaps: How Sustainable Can We Be?

PubMed

Pradhan, Prajal; Fischer, Günther; van Velthuizen, Harrij; Reusser, Dominik E; Kropp, Juergen P

2015-01-01

Global food production needs to be increased by 60-110% between 2005 and 2050 to meet growing food and feed demand. Intensification and/or expansion of agriculture are the two main options available to meet the growing crop demands. Land conversion to expand cultivated land increases GHG emissions and impacts biodiversity and ecosystem services. Closing yield gaps to attain potential yields may be a viable option to increase the global crop production. Traditional methods of agricultural intensification often have negative externalities. Therefore, there is a need to explore location-specific methods of sustainable agricultural intensification. We identified regions where the achievement of potential crop calorie production on currently cultivated land will meet the present and future food demand based on scenario analyses considering population growth and changes in dietary habits. By closing yield gaps in the current irrigated and rain-fed cultivated land, about 24% and 80% more crop calories can respectively be produced compared to 2000. Most countries will reach food self-sufficiency or improve their current food self-sufficiency levels if potential crop production levels are achieved. As a novel approach, we defined specific input and agricultural management strategies required to achieve the potential production by overcoming biophysical and socioeconomic constraints causing yield gaps. The management strategies include: fertilizers, pesticides, advanced soil management, land improvement, management strategies coping with weather induced yield variability, and improving market accessibility. Finally, we estimated the required fertilizers (N, P2O5, and K2O) to attain the potential yields. Globally, N-fertilizer application needs to increase by 45-73%, P2O5-fertilizer by 22-46%, and K2O-fertilizer by 2-3 times compared to the year 2010 to attain potential crop production. The sustainability of such agricultural intensification largely depends on the way

Progress on plague vaccine development.

PubMed

Rosenzweig, Jason A; Jejelowo, Olufisayo; Sha, Jian; Erova, Tatiana E; Brackman, Sheri M; Kirtley, Michelle L; van Lier, Cristina J; Chopra, Ashok K

2011-07-01

Yersinia pestis (YP), the gram-negative plague bacterium, has shaped human history unlike any other pathogen known to mankind. YP (transmitted by the bite of an infected flea) diverged only recently from the related enteric pathogen Yersinia pseudotuberculosis but causes radically different diseases. Three forms of plague exist in humans: bubonic (swollen lymph nodes or bubos), septicemic (spread of YP through the lymphatics or bloodstream from the bubos to other organs), and contagious, pneumonic plague which can be communicated via YP-charged respiratory droplets resulting in person-person transmission and rapid death if left untreated (50-90% mortality). Despite the potential threat of weaponized YP being employed in bioterrorism and YP infections remaining prevalent in endemic regions of the world where rodent populations are high (including the four corner regions of the USA), an efficacious vaccine that confers immunoprotection has yet to be developed. This review article will describe the current vaccine candidates being evaluated in various model systems and provide an overall summary on the progress of this important endeavor.

Closing yield gaps: perils and possibilities for biodiversity conservation.

PubMed

Phalan, Ben; Green, Rhys; Balmford, Andrew

2014-04-05

Increasing agricultural productivity to 'close yield gaps' creates both perils and possibilities for biodiversity conservation. Yield increases often have negative impacts on species within farmland, but at the same time could potentially make it more feasible to minimize further cropland expansion into natural habitats. We combine global data on yield gaps, projected future production of maize, rice and wheat, the distributions of birds and their estimated sensitivity to changes in crop yields to map where it might be most beneficial for bird conservation to close yield gaps as part of a land-sparing strategy, and where doing so might be most damaging. Closing yield gaps to attainable levels to meet projected demand in 2050 could potentially help spare an area equivalent to that of the Indian subcontinent. Increasing yields this much on existing farmland would inevitably reduce its biodiversity, and therefore we advocate efforts both to constrain further increases in global food demand, and to identify the least harmful ways of increasing yields. The land-sparing potential of closing yield gaps will not be realized without specific mechanisms to link yield increases to habitat protection (and restoration), and therefore we suggest that conservationists, farmers, crop scientists and policy-makers collaborate to explore promising mechanisms.

Closing yield gaps: perils and possibilities for biodiversity conservation

PubMed Central

Phalan, Ben; Green, Rhys; Balmford, Andrew

2014-01-01

Increasing agricultural productivity to ‘close yield gaps’ creates both perils and possibilities for biodiversity conservation. Yield increases often have negative impacts on species within farmland, but at the same time could potentially make it more feasible to minimize further cropland expansion into natural habitats. We combine global data on yield gaps, projected future production of maize, rice and wheat, the distributions of birds and their estimated sensitivity to changes in crop yields to map where it might be most beneficial for bird conservation to close yield gaps as part of a land-sparing strategy, and where doing so might be most damaging. Closing yield gaps to attainable levels to meet projected demand in 2050 could potentially help spare an area equivalent to that of the Indian subcontinent. Increasing yields this much on existing farmland would inevitably reduce its biodiversity, and therefore we advocate efforts both to constrain further increases in global food demand, and to identify the least harmful ways of increasing yields. The land-sparing potential of closing yield gaps will not be realized without specific mechanisms to link yield increases to habitat protection (and restoration), and therefore we suggest that conservationists, farmers, crop scientists and policy-makers collaborate to explore promising mechanisms. PMID:24535392

Rx for low cash yields.

PubMed

Tobe, Chris

2003-10-01

Certain strategies can offer not-for-profit hospitals potentially greater investment yields while maintaining stability and principal safety. Treasury inflation-indexed securities can offer good returns, low volatility, and inflation protection. "Enhanced cash" strategies offer liquidity and help to preserve capital. Stable value "wrappers" allow hospitals to pursue higher-yielding fixed-income securities without an increase in volatility.

Ethiopian Wheat Yield and Yield Gap Estimation: A Spatial Small Area Integrated Data Approach

NASA Astrophysics Data System (ADS)

Mann, M.; Warner, J.

2015-12-01

Despite the collection of routine annual agricultural surveys and significant advances in GIS and remote sensing products, little econometric research has been undertaken in predicting developing nation's agricultural yields. In this paper, we explore the determinants of wheat output per hectare in Ethiopia during the 2011-2013 Meher crop seasons aggregated to the woreda administrative area. Using a panel data approach, combining national agricultural field surveys with relevant GIS and remote sensing products, the model explains nearly 40% of the total variation in wheat output per hectare across the country. The model also identifies specific contributors to wheat yields that include farm management techniques (eg. area planted, improved seed, fertilizer, irrigation), weather (eg. rainfall), water availability (vegetation and moisture deficit indexes) and policy intervention. Our findings suggest that woredas produce between 9.8 and 86.5% of their potential wheat output per hectare given their altitude, weather conditions, terrain, and plant health. At the median, Amhara, Oromiya, SNNP, and Tigray produce 48.6, 51.5, 49.7, and 61.3% of their local attainable yields, respectively. This research has a broad range of applications, especially from a public policy perspective: identifying causes of yield fluctuations, remotely evaluating larger agricultural intervention packages, and analyzing relative yield potential. Overall, the combination of field surveys with spatial data can be used to identify management priorities for improving production at a variety of administrative levels.

Modeling homeorhetic trajectories of milk component yields, body composition and dry-matter intake in dairy cows: Influence of parity, milk production potential and breed.

PubMed

Daniel, J B; Friggens, N C; van Laar, H; Ingvartsen, K L; Sauvant, D

2018-06-01

The control of nutrient partitioning is complex and affected by many factors, among them physiological state and production potential. Therefore, the current model aims to provide for dairy cows a dynamic framework to predict a consistent set of reference performance patterns (milk component yields, body composition change, dry-matter intake) sensitive to physiological status across a range of milk production potentials (within and between breeds). Flows and partition of net energy toward maintenance, growth, gestation, body reserves and milk components are described in the model. The structure of the model is characterized by two sub-models, a regulating sub-model of homeorhetic control which sets dynamic partitioning rules along the lactation, and an operating sub-model that translates this into animal performance. The regulating sub-model describes lactation as the result of three driving forces: (1) use of previously acquired resources through mobilization, (2) acquisition of new resources with a priority of partition towards milk and (3) subsequent use of resources towards body reserves gain. The dynamics of these three driving forces were adjusted separately for fat (milk and body), protein (milk and body) and lactose (milk). Milk yield is predicted from lactose and protein yields with an empirical equation developed from literature data. The model predicts desired dry-matter intake as an outcome of net energy requirements for a given dietary net energy content. The parameters controlling milk component yields and body composition changes were calibrated using two data sets in which the diet was the same for all animals. Weekly data from Holstein dairy cows was used to calibrate the model within-breed across milk production potentials. A second data set was used to evaluate the model and to calibrate it for breed differences (Holstein, Danish Red and Jersey) on the mobilization/reconstitution of body composition and on the yield of individual milk components

Potential Impacts of Increased Management Intensities on Planted Pine Growth and Yield and Timber Supply Modeling in the South

Treesearch

Jacek P. Siry; Frederick W. Cubbage; Andy J. Malmquist

1999-01-01

The South can increase pine productivity on its forest lands as increased timber prices make returns from intensified forest management more profitable. We determined the most likely management intensities on industrial lands resulting in five management intensity classes. They are used to estimate the potential growth and yield levels, and compare these to empirical...

Closing Yield Gaps: How Sustainable Can We Be?

PubMed Central

Pradhan, Prajal; Fischer, Günther; van Velthuizen, Harrij; Reusser, Dominik E.; Kropp, Juergen P.

2015-01-01

Global food production needs to be increased by 60–110% between 2005 and 2050 to meet growing food and feed demand. Intensification and/or expansion of agriculture are the two main options available to meet the growing crop demands. Land conversion to expand cultivated land increases GHG emissions and impacts biodiversity and ecosystem services. Closing yield gaps to attain potential yields may be a viable option to increase the global crop production. Traditional methods of agricultural intensification often have negative externalities. Therefore, there is a need to explore location-specific methods of sustainable agricultural intensification. We identified regions where the achievement of potential crop calorie production on currently cultivated land will meet the present and future food demand based on scenario analyses considering population growth and changes in dietary habits. By closing yield gaps in the current irrigated and rain-fed cultivated land, about 24% and 80% more crop calories can respectively be produced compared to 2000. Most countries will reach food self-sufficiency or improve their current food self-sufficiency levels if potential crop production levels are achieved. As a novel approach, we defined specific input and agricultural management strategies required to achieve the potential production by overcoming biophysical and socioeconomic constraints causing yield gaps. The management strategies include: fertilizers, pesticides, advanced soil management, land improvement, management strategies coping with weather induced yield variability, and improving market accessibility. Finally, we estimated the required fertilizers (N, P2O5, and K2O) to attain the potential yields. Globally, N-fertilizer application needs to increase by 45–73%, P2O5-fertilizer by 22–46%, and K2O-fertilizer by 2–3 times compared to the year 2010 to attain potential crop production. The sustainability of such agricultural intensification largely depends on the way

The Z {yields} cc-bar {yields} {gamma}{gamma}*, Z {yields} bb-bar {yields} {gamma}{gamma}* triangle diagrams and the Z {yields} {gamma}{psi}, Z {yields} {gamma}Y decays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Achasov, N. N., E-mail: achasov@math.nsc.ru

2011-03-15

The approach to the Z {yields} {gamma}{psi} and Z {yields} {gamma}Y decay study is presented in detail, based on the sum rules for the Z {yields} cc-bar {yields} {gamma}{gamma}* and Z {yields} bb-bar {yields} {gamma}{gamma}* amplitudes and their derivatives. The branching ratios of the Z {yields} {gamma}{psi} and Z {yields} {gamma}Y decays are calculated for different hypotheses on saturation of the sum rules. The lower bounds of {Sigma}{sub {psi}} BR(Z {yields} {gamma}{psi}) = 1.95 Multiplication-Sign 10{sup -7} and {Sigma}{sub {upsilon}} BR(Z {yields} {gamma}Y) = 7.23 Multiplication-Sign 10{sup -7} are found. Deviations from the lower bounds are discussed, including the possibilitymore » of BR(Z {yields} {gamma}J/{psi}(1S)) {approx} BR(Z {yields} {gamma}Y(1S)) {approx} 10{sup -6}, that could be probably measured in LHC. The angular distributions in the Z {yields} {gamma}{psi} and Z {yields} {gamma}Y decays are also calculated.« less

Crop status evaluations and yield predictions

NASA Technical Reports Server (NTRS)

Haun, J. R.

1976-01-01

One phase of the large area crop inventory project is presented. Wheat yield models based on the input of environmental variables potentially obtainable through the use of space remote sensing were developed and demonstrated. By the use of a unique method for visually qualifying daily plant development and subsequent multifactor computer analyses, it was possible to develop practical models for predicting crop development and yield. Development of wheat yield prediction models was based on the discovery that morphological changes in plants are detected and quantified on a daily basis, and that this change during a portion of the season was proportional to yield.

Emotional wellbeing and mental health: an exploration into health promotion in young people and families.

PubMed

Coverdale, Gillian E; Long, Andrew F

2015-01-01

Promoting mental health and emotional wellbeing (EWB) in children and young people (YP) is vitally important for their psycho-social development. Critical review of the literature reveals a dearth of research that has explored the perspective of the child, adolescent or adult in this concept, with much research being intervention focused and promoted at crisis level. The current study aims to address this gap in understanding of young persons' and parents' perspectives. A small-scale, exploratory qualitative study was conducted with YP, and parents of YP aimed at exploring the meaning of EWB and how it could be promoted. Data were collected via focus groups with 15 YP (aged 18-24 years) and 15 interviews with parents of a different group of YP. Study participants identified key constructs for good EWB as stability, coping ability, happiness, confidence, balance, empathy and being grounded. Feeling comfortable with self, managing and controlling emotions and having the confidence to persevere with challenges were all felt to contribute to a positive sense of EWB. Sources of support were overwhelmingly cited as family and friends, with schools identified as a potentially good environment for supporting and promoting the EWB of pupils. Participants stressed the need for a positive attitude change towards YP, advocating this as promoting a sense of belonging and community citizenship. A lay-informed 'recipe' for successful EWB promotion is drawn out, centred on the core goal of raising awareness and understanding of YP's EWB, in the YP themselves, their parents, schools and the wider community. This research provides key messages for society, policy makers, education and public health and healthcare practitioners for integration into the delivery of services for YP and families that include education on supporting EWB, activities for YP and a multi-agency approach to supporting families within the community. © Royal Society for Public Health 2014.

Early Yields of Biomass Plantations in the North-Central U.S.

Treesearch

Edward Hansen

1990-01-01

A network of hybrid poplar short-rotation plantations was established across the north-central region of the U.S. during 1986-1988. This paper documents the greater than expected early yields from these plantations and dicusses potential yields and uncertainties surrounding potential yield estimates.

Fewer not more leaves - Key to obtaining the needed jump in crop yield potential and water use efficiency

NASA Astrophysics Data System (ADS)

Srinivasan, V.; Kumar, P.; Long, S.

2013-12-01

Word food and feed supply needs to increase by 75% by 2050 to meet the increasing demands of our growing population. Soybean which is the world`s fourth most important crop in terms of total production at 250 million Mt/yr is a key protein source, and together with rice and wheat, are experiencing declining global yield increases year on year. At present rates of improvement, 2050 targets cannot be reached without new innovations. In this study we demonstrate an innovative approach that could provide a yield jump. While, natural selection favors individual plants to maximize leaf production to maximize light interception and shade competitors, the presence of this trait in domestic crops could be disadvantageous. In addition, rising CO2 causes increased leaf production further exacerbating the problem. Here, we show by mathematical model and field experiment that, a modern cultivar growing at the center of US soy cultivation produces too many leaves and reduction to an optimal level would increase yield. Our model results indicate that an LAI of 3.5 and 3.8 produces maximal rates of net canopy assimilation under ambient and elevated CO2 conditions respectively. However, observed peak LAI values are 6.9 and 7.5 under ambient and elevated CO2 conditions respectively. This results in a NPP loss of 30% and 20% under ambient and elevated CO2 conditions respectively. Furthermore, the optimal LAI results in a decreased transpiration of up to 30% thus increasing water use efficiency. We show that as LAI increases, the tradeoffs between diminishing day time gains in NPP, and increasing losses in respiration is responsible for this effect. By designing a more optimum canopy, we can increase NPP and this potentially translates to increased seed yield. To test this model result, we perform canopy manipulation experiments on soybean plants, where we artificially decrease LAI by periodically removing young and emerging leaves throughout the growing season (after pod onset), and

Redefining yield gaps at various spatial scales

NASA Astrophysics Data System (ADS)

Meng, K.; Fishman, R.; Norstrom, A. V.; Diekert, F. K.; Engstrom, G.; Gars, J.; McCarney, G. R.; Sjostedt, M.

2013-12-01

Recent research has highlighted the prevalence of 'yield gaps' around the world and the importance of closing them for global food security. However, the traditional concept of yield gap -defined as the difference between observed and optimal yield under biophysical conditions - omit relevant socio-economic and ecological constraints and thus offer limited guidance on potential policy interventions. This paper proposes alternative definitions of yield gaps by incorporating rich, high resolution, national and sub-national agricultural datasets. We examine feasible efforts to 'close yield gaps' at various spatial scales and across different socio-economic and ecological domains.

Role of one N-linked oligosaccharide chain on canine herpesvirus gD in its biological activity.

PubMed

Maeda, K; Yokoyama, N; Fujita, K; Xuan, X; Mikami, T

1997-12-01

The YP11mu strain of a plaque-selected canine herpesvirus (CHV) encoded a smaller molecular weight (MW) of gD than those of other strains including YP2 strain (Xuan et al., 1990). When nucleotide sequence of the mutated gD of YP11mu strain (gD(YP11mu)) was compared with that of gDs of other CHV strains, gD(YP11mu) lacked 12 nucleotides encoding 4 amino acids, NKTI, including one predicted potential N-linked glycosylation site and no other change was found in other regions. When the gD(YP11mu) and gD of YP2 strain (gD(YP2)) expressed in COS-7 and insect (Spodoptera frugiperda; Sf9) cells were compared each other, both gDs reacted with a panel of monoclonal antibodies (MAbs) against CHV gD by indirect immunofluorescence analysis and the gD(YP11mu) possessed an MW of approximately 47-51 and 39-44 kDa in COS-7 and Sf9 cells, respectively, which were smaller than the expressed gD(YP2) (approximately 51-55 and 41-46 kDa, respectively) by immunoblot analysis. After treatment with tunicamycin, the MW of both gDs in Sf9 cells became approximately 37 kDa. When hemagglutination (HA) test using canine red blood cells (RBC) were carried out, lysates of Sf9 cells expressing CHV gDs agglutinated canine RBC. Serum from mice inoculated with lysates of Sf9 cells expressing the gDs possessed a high titer of virus-neutralizing (VN) activities against CHV. These results indicated that the deletion of 4 amino acids possessing approximately 4 kDa of glyco-chain from gD of CHV in mammalian cells does not affect HA activity and VN antibody-inducing activity and that this deletion of gD(YP11mu) might be a good selective marker for development of recombinant viruses as a live vaccine.

Growth, reproductive phenology and yield responses of a potential biofuel plant, Jatropha curcas grown under projected 2050 levels of elevated CO2.

PubMed

Kumar, Sumit; Chaitanya, Bharatula S K; Ghatty, Sreenivas; Reddy, Attipalli R

2014-11-01

Jatropha (Jatropha curcas) is a non-edible oil producing plant which is being advocated as an alternative biofuel energy resource. Its ability to grow in diverse soil conditions and minimal requirements of essential agronomical inputs compared with other oilseed crops makes it viable for cost-effective advanced biofuel production. We designed a study to investigate the effects of elevated carbon dioxide concentration ([CO(2)]) (550 ppm) on the growth, reproductive development, source-sink relationships, fruit and seed yield of J. curcas. We report, for the first time that elevated CO(2) significantly influences reproductive characteristics of Jatropha and improve its fruit and seed yields. Net photosynthetic rate of Jatropha was 50% higher in plants grown in elevated CO(2) compared with field and ambient CO(2) -grown plants. The study also revealed that elevated CO(2) atmosphere significantly increased female to male flower ratio, above ground biomass and carbon sequestration potential in Jatropha (24 kg carbon per tree) after 1 year. Our data demonstrate that J. curcas was able to sustain enhanced rate of photosynthesis in elevated CO(2) conditions as it had sufficient sink strength to balance the increased biomass yields. Our study also elucidates that the economically important traits including fruit and seed yield in elevated CO(2) conditions were significantly high in J. curcas that holds great promise as a potential biofuel tree species for the future high CO(2) world. © 2014 Scandinavian Plant Physiology Society.

Character-marked furniture: potential for lumber yield increase in rip-first rough mills

Treesearch

Urs Buehlmann; Janice K. Wiedenbeck; D. Earl Kline; D. Earl Kline

1998-01-01

The inclusion of character marks in furniture parts increases part yield at least as much as previously estimated by industrial practitioners and scientists specializing in yield efficiency. However, character-marked furniture is uncommon in the more popular North American furniture species and designs. Opportunities for extending the hardwood resource associated with...

Potential of multiseeded mutant (msd) to boost sorghum grain yield

USDA-ARS?s Scientific Manuscript database

Seed number per plant is an important determinant of the grain yield in cereal and other crops. We have isolated a class of multiseeded (msd) sorghum (Sorghum bicolor L. Moench) mutants that are capable of producing three times the seed number and twice the seed weight per panicle as compared with t...

Impact of Lygus spp. (Hemiptera: Miridae) on damage, yield and quality of lesquerella (Physaria fendleri), a potential new oil-seed crop.

PubMed

Naranjo, Steven E; Ellsworth, Peter C; Dierig, David A

2011-10-01

Lesquerella, Physaria fendleri (A. Gray) S. Watson, is a mustard native to the western United States and is currently being developed as a commercial source of valuable hydroxy fatty acids that can be used in a number of industrial applications, including biolubricants, biofuel additives, motor oils, resins, waxes, nylons, plastics, corrosion inhibitors, cosmetics, and coatings. The plant is cultivated as a winter-spring annual and in the desert southwest it harbors large populations of arthropods, several of which could be significant pests once production expands. Lygus spp. (Hemiptera: Miridae) are common in lesquerella and are known pests of a number of agronomic and horticultural crops where they feed primarily on reproductive tissues. A 4-yr replicated plot study was undertaken to evaluate the probable impact of Lygus spp. on production of this potential new crop. Plant damage and subsequent seed yield and quality were examined relative to variable and representative densities of Lygus spp. (0.3-4.9 insects per sweep net) resulting from variable frequency and timing of insecticide applications. Increasing damage to various fruiting structures (flowers [0.9-13.9%], buds [1.2-7.1%], and seed pods [19.4-42.5%]) was significantly associated with increasing pest abundance, particularly the abundance of nymphs, in all years. This damage, however, did not consistently translate into reductions in seed yield (481-1,336 kg/ha), individual seed weight (0.5-0.7 g per 1,000 seed), or seed oil content (21.8-30.4%), and pest abundance generally explained relatively little of the variation in crop yield and quality. Negative effects on yield were not sensitive to the timing of pest damage (early versus late season) but were more pronounced during years when potential yields were lower due to weed competition and other agronomic factors. Results suggest that if the crop is established and managed in a more optimal fashion, Lygus spp. may not significantly limit yield

Character-marked furniture: potential for lumber yield increase in crosscut-first rough mills

Treesearch

Urs Buehlmann; Janice K. Wiedenbeck; E. Earl Kline; E. Earl Kline

1999-01-01

Including character marks in dimension parts of the furniture, cabinet, and dimension industries offers an opportunity to increase lumber yield substantially. However, little quantitative knowledge exists as to how the incorporation of character marks in parts influences yield when processing lumber in a crosscut-first rough mill. Using computer simulation, this study...

Calculation of total free energy yield as an alternative approach for predicting the importance of potential chemolithotrophic reactions in geothermal springs.

PubMed

Dodsworth, Jeremy A; McDonald, Austin I; Hedlund, Brian P

2012-08-01

To inform hypotheses regarding the relative importance of chemolithotrophic metabolisms in geothermal environments, we calculated free energy yields of 26 chemical reactions potentially supporting chemolithotrophy in two US Great Basin hot springs, taking into account the effects of changing reactant and product activities on the Gibbs free energy as each reaction progressed. Results ranged from 1.2 × 10(-5) to 3.6 J kg(-1) spring water, or 3.7 × 10(-5) to 11.5 J s(-1) based on measured flow rates, with aerobic oxidation of CH(4) or NH4 + giving the highest average yields. Energy yields calculated without constraining pH were similar to those at constant pH except for reactions where H(+) was consumed, which often had significantly lower yields when pH was unconstrained. In contrast to the commonly used normalization of reaction chemical affinities per mole of electrons transferred, reaction energy yields for a given oxidant varied by several orders of magnitude and were more sensitive to differences in the activities of products and reactants. The high energy yield of aerobic ammonia oxidation is consistent with previous observations of significant ammonia oxidation rates and abundant ammonia-oxidizing archaea in sediments of these springs. This approach offers an additional lens through which to view the thermodynamic landscape of geothermal springs. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

An improvement of surfactin production by B. subtilis BBG131 using design of experiments in microbioreactors and continuous process in bubbleless membrane bioreactor.

PubMed

Motta Dos Santos, Luiz Fernando; Coutte, François; Ravallec, Rozenn; Dhulster, Pascal; Tournier-Couturier, Lucie; Jacques, Philippe

2016-10-01

Culture medium elements were analysed by a screening DoE to identify their influence in surfactin specific production by a surfactin constitutive overproducing Bacillus subtilis strain. Statistics pointed the major enhancement caused by high glutamic acid concentrations, as well as a minor positive influence of tryptophan and glucose. Successively, a central composite design was performed in microplate bioreactors using a BioLector®, in which variations of these impressive parameters, glucose, glutamic acid and tryptophan concentrations were selected for optimization of product-biomass yield (YP/X). Results were exploited in combination with a RSM. In absolute terms, experiments attained an YP/X 3.28-fold higher than those obtained in Landy medium, a usual culture medium used for lipopeptide production by B. subtilis. Therefore, two medium compositions for enhancing biomass and surfactin specific production were proposed and tested in continuous regime in a bubbleless membrane bioreactor. An YP/X increase of 2.26-fold was observed in bioreactor scale. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis, Rietveld refinements, Infrared and Raman spectroscopy studies of the sodium diphosphate NaCryFe1-yP2O7 (0 ≤ y ≤ 1)

NASA Astrophysics Data System (ADS)

Bih, H.; Saadoune, I.; Bih, L.; Mansori, M.; ToufiK, H.; Fuess, H.; Ehrenberg, H.

2016-01-01

In the present study we report on the synthesis and crystal structure studies of NaCryFe1-yP2O7 sodium diphosphate solid solution (0 ≤ y ≤ 1). The X-ray diffraction shows that these compounds are isostructural with NaFeP2O7 and NaCrP2O7 (space group P21/c (C2h5) Z = 4). The Rietveld refinements based on the XRD patterns show the existence of a continuous solid solution over the whole composition range (0 ≤ y ≤ 1). A continuous evolution of the monoclinic unit cell parameters was obtained. The transition metal ions (Cr3+ and/or Fe3+) connect the diphosphate anions forming a three-dimensional network with cages filled by Na+ cations. IR and Raman spectra have been interpreted using factor group analysis. A small shift of the band frequencies is observed when Fe is substituted by Cr. The POP bridge angles are determined from Lazarev's relation and agree well with those deduced from the crystal structure refinement.

The role of inoculum's origin on the methane yield of different substrates in biochemical methane potential (BMP) tests.

PubMed

Koch, Konrad; Lippert, Thomas; Drewes, Jörg E

2017-11-01

The impact of the inoculum's origin on the methane yield in Biochemical Methane Potential (BMP) tests was investigated. The three most commonly applied inocula were chosen, originating from (i) a digester of a wastewater treatment plant, (ii) an agricultural biogas plant treating manure and energy crops, and (iii) a biowaste treatment plant. The performance of each inoculum was tested with four different substrates, namely sewage sludge, dried whole crop maize, food waste, and microcrystalline cellulose as a typical reference material. The results revealed that the choice of inoculum had no significant impact on the specific methane yield of the tested substrates except for cellulose. Still, the specific methane production rate was significantly influenced by the choice of the inoculum especially for sewage sludge, but also for food waste and cellulose, whereas it became clear that an inoculum adapted to a substrate is beneficial for a speedy digestion. Copyright © 2017 Elsevier Ltd. All rights reserved.

An evaluation of the potential yield of indium recycled from end-of-life LCDs: A case study in China.

PubMed

Wang, Hengguang; Gu, Yifan; Wu, Yufeng; Zhang, Yi-Nan; Wang, Wei

2015-12-01

With the advances in electronics and information technology, China has gradually become the largest consumer of household appliances (HAs). Increasingly, end-of-life (EOL) HAs are generated in China. EOL recycling is a promising strategy to reduce dependence on virgin production, and indium is one of the recycled substances. The potential yield of indium recycling has not been systematically evaluated in China thus far. This paper estimates the potential yield of recycled indium from waste liquid crystal displays (LCDs) in China during the period from 2015 to 2030. The quantities of indium that will be used to produce LCDs are also predicted. The estimates focus on the following three key LCD waste sources: LCD TVs, desktop computers and portable computers. The results show that the demand for indium will be increasing in the near future. It is expected that 350 tonnes of indium will be needed to produce LCDs in China in 2035. The indium recycled from EOL LCDs, however, is much less than the demand and only accounts for approximately 48% of the indium demand. The sustainable index of indium is always less than 0.5. Therefore, future indium recycling efforts should focus on the development of recycling technology and the improvement of the relevant policy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Concepts in Biochemistry: Chemical Synthesis of DNA.

ERIC Educational Resources Information Center

Caruthers, Marvin H.

1989-01-01

Outlines the chemistry of the rapid synthesis of relatively large DNA fragments (100-200 monomers each) with yields exceeding 99 percent per coupling. DNA synthesis methodologies are outlined and a polymer-supported synthesis of DNA using deoxynucleoside phosphoramidites is described with structural formulas. (YP)

Effects of ecological and conventional agricultural intensification practices on maize yields in sub-Saharan Africa under potential climate change

NASA Astrophysics Data System (ADS)

Folberth, Christian; Yang, Hong; Gaiser, Thomas; Liu, Junguo; Wang, Xiuying; Williams, Jimmy; Schulin, Rainer

2014-04-01

Much of Africa is among the world’s regions with lowest yields in staple food crops, and climate change is expected to make it more difficult to catch up in crop production in particular in the long run. Various agronomic measures have been proposed for lifting agricultural production in Africa and to adapt it to climate change. Here, we present a projection of potential climate change impacts on maize yields under different intensification options in Sub-Saharan Africa (SSA) using an agronomic model, GIS-based EPIC (GEPIC). Fallow and nutrient management options taken into account are (a) conventional intensification with high mineral N supply and a bare fallow, (b) moderate mineral N supply and cowpea rotation, and (c) moderate mineral N supply and rotation with a fast growing N fixing tree Sesbania sesban. The simulations suggest that until the 2040s rotation with Sesbania will lead to an increase in yields due to increasing N supply besides improving water infiltration and soils’ water holding capacity. Intensive cultivation with a bare fallow or an herbaceous crop like cowpea in the rotation is predicted to result in lower yields and increased soil erosion during the same time span. However, yields are projected to decrease in all management scenarios towards the end of the century, should temperature increase beyond critical thresholds. The results suggest that the effect of eco-intensification as a sole means of adapting agriculture to climate change is limited in Sub-Saharan Africa. Highly adverse temperatures would rather have to be faced by improved heat tolerant cultivars, while strongly adverse decreases in precipitation would have to be faced by expanding irrigation where feasible. While the evaluation of changes in agro-environmental variables like soil organic carbon, erosion, and soil humidity hints that these are major factors influencing climate change resilience of the field crop, no direct relationship between these factors, crop yields, and

Weather-based forecasts of California crop yields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lobell, D B; Cahill, K N; Field, C B

2005-09-26

Crop yield forecasts provide useful information to a range of users. Yields for several crops in California are currently forecast based on field surveys and farmer interviews, while for many crops official forecasts do not exist. As broad-scale crop yields are largely dependent on weather, measurements from existing meteorological stations have the potential to provide a reliable, timely, and cost-effective means to anticipate crop yields. We developed weather-based models of state-wide yields for 12 major California crops (wine grapes, lettuce, almonds, strawberries, table grapes, hay, oranges, cotton, tomatoes, walnuts, avocados, and pistachios), and tested their accuracy using cross-validation over themore » 1980-2003 period. Many crops were forecast with high accuracy, as judged by the percent of yield variation explained by the forecast, the number of yields with correctly predicted direction of yield change, or the number of yields with correctly predicted extreme yields. The most successfully modeled crop was almonds, with 81% of yield variance captured by the forecast. Predictions for most crops relied on weather measurements well before harvest time, allowing for lead times that were longer than existing procedures in many cases.« less

Sensitivity of commercial pumpkin yield to potential decline among different groups of pollinating bees.

PubMed

Pfister, Sonja C; Eckerter, Philipp W; Schirmel, Jens; Cresswell, James E; Entling, Martin H

2017-05-01

The yield of animal-pollinated crops is threatened by bee declines, but its precise sensitivity is poorly known. We therefore determined the yield dependence of Hokkaido pumpkin in Germany on insect pollination by quantifying: (i) the relationship between pollen receipt and fruit set and (ii) the cumulative pollen deposition of each pollinator group. We found that approximately 2500 pollen grains per flower were needed to maximize fruit set. At the measured rates of flower visitation, we estimated that bumblebees (21 visits/flower lifetime, 864 grains/visit) or honeybees (123 visits, 260 grains) could individually achieve maximum crop yield, whereas halictid bees are ineffective (11 visits, 16 grains). The pollinator fauna was capable of delivering 20 times the necessary amount of pollen. We therefore estimate that pumpkin yield was not pollination-limited in our study region and that it is currently fairly resilient to single declines of honeybees or wild bumblebees.

Potential of deficit irrigation, irrigation cut-offs, and crop thinning to maintain yield and fruit quality with less water in northern highbush blueberry

USDA-ARS?s Scientific Manuscript database

Drought and mandatory water restrictions are limiting the availability of irrigation water in many important blueberry growing regions, including Oregon, Washington, and California. New strategies are needed to maintain yield and fruit quality with less water. Three potential options, including defi...

Phenotyping Drought Tolerance and Yield Potential of Warm-Season Legumes Through Field- and Airborne-Based Hyperspectral VSWIR Sensing

NASA Astrophysics Data System (ADS)

Drewry, D.; Berny-Mier y Teran, J. C.; Dutta, D.; Gepts, P.

2017-12-01

Hyperspectral sensing in the visible through shortwave infrared (VSWIR) portion of the spectrum has been demonstrated to provide significant information on the structural and functional properties of vegetation, resulting in powerful techniques to discern species differences, characterize crop nutrient or water stress, and quantify the density of foliage in agricultural fields. Modern machine-learning techniques allow for the entire set of spectral bands, on the order of hundreds with modern field and airborne spectrometers, to be used to develop models that can simultaneously retrieve a variety of foliar chemical compounds and hydrological and structural states. The application of these techniques, in the context of leaf-level measurements of VSWIR reflectance, or more complicated remote airborne surveys, has the potential to revolutionize high-throughput methods to phenotype germplasm that optimizes yield, resource-use efficiencies, or alternate objectives related to disease resistance or biomass accumulation, for example. Here we focus on breeding trials for a set of warm-season legumes, conducted in both greenhouse and field settings, and spanning a set of diverse genotypes providing a range of adaptation to drought and yield potential in the context of the semi-arid climate cultivation. At the leaf-level, a large set of spectral reflectance measurements spanning 400-2500 nanometers were made for plants across various growth stages in field experiments that induced severe drought, along with sampling for relevant trait values. Here we will discuss the development and performance of algorithms for a range of leaf traits related to gas exchange, leaf structure, hydrological status, nutrient contents and stable isotope discrimination, along with their relationships to drought resistance and yield. We likewise discuss the effectiveness of quantifying relevant foliar and canopy traits through airborne imaging spectroscopy from small unmanned vehicles (sUAVs), and

Sperm yield after single layer centrifugation with Androcoll-E is related to the potential fertility of the original ejaculate.

PubMed

Morrell, J M; Stuhtmann, G; Meurling, S; Lundgren, A; Winblad, C; Macias Garcia, B; Johannisson, A

2014-05-01

Many attempts have been made to identify laboratory tests that are predictive of sperm fertility, both to improve the quality of stallion semen doses for artificial insemination (AI) and to identify potential breeding sires if no fertility data are available. Sperm quality at the stud is mostly evaluated by assessing subjective motility, although this parameter can be poorly indicative of fertility. Sperm morphology and chromatin integrity in Swedish stallions are correlated to pregnancy rate after AI. Because single layer centrifugation (SLC) selects for spermatozoa with normal morphology and good chromatin, retrospective analysis was carried out to investigate whether sperm yield after SLC is linked to potential fertility. Commercial semen doses for AI from 24 stallions (five stallions with four ejaculates each, 19 stallions with three ejaculates each; n = 77) obtained during the breeding season were cooled, and sent overnight to the Swedish University of Agricultural Sciences in an insulated box for evaluation, with other doses being sent to studs for commercial AI. On arrival at Swedish University of Agricultural Sciences, the semen was used for SLC and also for evaluation of sperm motility, membrane integrity, chromatin integrity, and morphology. The seasonal pregnancy rates for each stallion were available. The yield of progressively motile spermatozoa after SLC (calculated as a proportion of the initial load) was found to be highly correlated with pregnancy rate (r = 0.75; P < 0.001). Chromatin damage was highly negatively correlated with pregnancy rate (r = -0.69; P < 0.001). Pregnancy rate was also correlated with membrane integrity (r = 0.58; P < 0.01), progressive motility (r = 0.63; P < 0.01), and normal morphology (r = 0.45; P < 0.05). In conclusion, these preliminary results show that sperm yield after SLC is related to the potential fertility of the original ejaculate, and could be an alternative indicator of stallion fertility if breeding data are

Sensitivity of commercial pumpkin yield to potential decline among different groups of pollinating bees

PubMed Central

Eckerter, Philipp W.; Schirmel, Jens; Cresswell, James E.; Entling, Martin H.

2017-01-01

The yield of animal-pollinated crops is threatened by bee declines, but its precise sensitivity is poorly known. We therefore determined the yield dependence of Hokkaido pumpkin in Germany on insect pollination by quantifying: (i) the relationship between pollen receipt and fruit set and (ii) the cumulative pollen deposition of each pollinator group. We found that approximately 2500 pollen grains per flower were needed to maximize fruit set. At the measured rates of flower visitation, we estimated that bumblebees (21 visits/flower lifetime, 864 grains/visit) or honeybees (123 visits, 260 grains) could individually achieve maximum crop yield, whereas halictid bees are ineffective (11 visits, 16 grains). The pollinator fauna was capable of delivering 20 times the necessary amount of pollen. We therefore estimate that pumpkin yield was not pollination-limited in our study region and that it is currently fairly resilient to single declines of honeybees or wild bumblebees. PMID:28573019

Water yield and hydrology

Treesearch

Pamela J. Edwards; Charles A. Troendle

2012-01-01

Investigations of hydrologic responses resulting from reducing vegetation density are fairly common throughout the Eastern United States. Although most studies have focused on the potential for increasing water yields or documenting effects from intensive practices that far exceed what would be done for fuel-reduction objectives, data from some less-intensive...

Corecovery of lipids and fermentable sugars from Rhodosporidium toruloides using ionic liquid cosolvents: application of recycle to batch fermentation.

PubMed

Severa, Godwin; Kumar, Guneet; Cooney, Michael J

2014-01-01

This work evaluates the ability of an ionic liquid-methanol cosolvent system to extract lipids and recycle fermentable sugars recovered from oil-bearing Rhodosporidium toruloides grown in batch culture on defined media using glucose and xylose as carbon sources. Growth on the recycled mixed carbon substrate was successful with glucose consumed before xylose and overall cell mass to lipid yields (YP/X ) between 57% and 61% (w/w relative to whole dried cell mass) achieved. Enzymatic hydrolysis of the delipified carbohydrate fraction recovered approximately 9%-11% (w/w) of the whole dried cell mass as fermentable sugars, which were successfully recycled as carbon sources without further purification. In total, up to 70% (w/w) of the whole dried cell mass was recovered as lipids and fermentable sugars and the substrate to lipid yields (YP/S ) was increased from 0.12 to 0.16 g lipid/g carbohydrate consumed, highlighting the promise of this approach to process lipid bearing cell biomass. © 2014 American Institute of Chemical Engineers.

Value of the prognostic nutritional index in advanced gastric cancer treated with preoperative chemotherapy.

PubMed

Sun, Jianyi; Wang, Donghai; Mei, Ying; Jin, Hailong; Zhu, Kankai; Liu, Xiaosun; Zhang, Qing; Yu, Jiren

2017-03-01

The prognostic nutritional index (PNI) is a useful parameter indicating the immune and nutritional status of cancer patients; this study investigated the prognostic value of the PNI in advanced gastric cancer patients treated with preoperative chemotherapy. We retrospectively reviewed 117 advanced gastric cancer patients who met the inclusion criteria for preoperative chemotherapy and underwent surgical resection from July 2004 to December 2011. The patients were divided into PNI-high (PNI ≥ 45) and PNI-low (PNI < 45) groups. Clinicopathologic features, chemotherapy adverse events, and surgical complications were compared between the prechemotherapy PNI-high and PNI-low groups using the chi-square test. Survival analysis was performed using the Kaplan-Meier method and log-rank test. The Cox proportional hazard model was used to identify prognostic factors. Overall survival was better in the prechemotherapy PNI-high group than in the PNI-low group (hazard ratio [HR] = 2.237, 95% confidence interval [CI]: 1.271-3.393, P = 0.005), while there was no significant difference in Overall survival between the postchemotherapy PNI-high and PNI-low groups (P > 0.05). Cox regression analysis indicated that yield pathologic T (ypT), yield pathologic N (ypN) stage, and prechemotherapy PNI were independent prognostic factors (ypT: HR = 2.914, 95% CI = 1.312-6.470, P = 0.009; ypN: HR = 4.909, 95% CI = 1.764-13.660, P = 0.003; prechemotherapy PNI: HR = 1.963, 95% CI = 1.101-3.499, P = 0.022). The prechemotherapy PNI is a useful predictor of the long-term outcome of patients with advanced gastric cancer treated with preoperative chemotherapy. Copyright © 2016 Elsevier Inc. All rights reserved.

The role of nisin in fuel ethanol production with Saccharomyces cerevisiae.

PubMed

Peng, J; Zhang, L; Gu, Z-H; Ding, Z-Y; Shi, G-Y

2012-08-01

To investigate the effects of nisin on lactobacilli contamination of yeast during ethanol fermentation and to determine the appropriate concentration required to control the growth of selected lactobacilli in a YP/glucose media fermentation model. The lowest concentration of nisin tested (5 IU ml(-1) ) effectively controlled the contamination of YP/glucose media with 10(6) CFU ml(-1) lactobacilli. Lactic acid yield decreased from 5.0 to 2. 0 g l(-1) and potential ethanol yield losses owing to the growth and metabolism of Lactobacillus plantarum and Lactobacillus brevis were reduced by 11 and 7.8%, respectively. Approximately, equal concentrations of lactic acid were produced by Lact. plantarum and Lact. brevis in the presence of 5 and 2 IU ml(-1) nisin, respectively, thus demonstrating the relatively higher nisin sensitivity of Lact. brevis for the strains in this study. No differences were observed in the final ethanol concentrations produced by yeast in the absence of bacteria at any of the nisin concentrations tested. Metabolism of contaminating bacteria was reduced in the presence of 5 IU ml(-1) nisin, resulting in reduced lactic acid production and increased ethanol production by the yeast. Bacteriocins represent an alternative to the use of antibiotics for the control of bacterial contamination in fuel ethanol plants and may be important in preventing the emergence of antibiotic-resistant contaminating strains. © 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.

Anaerobic digestion of spring and winter wheat: Comparison of net energy yields.

PubMed

Rincón, Bárbara; Heaven, Sonia; Salter, Andrew M; Banks, Charles J

2016-10-14

Anaerobic digestion of wheat was investigated under batch conditions. The article compares the potential net energy yield between a winter wheat (sown in the autumn) and a spring wheat (sown in the spring) grown in the same year and harvested at the same growth stage in the same farm. The spring wheat had a slightly higher biochemical methane potential and required lower energy inputs in cultivation, but produced a lower dry biomass yield per hectare, which resulted in winter wheat providing the best overall net energy yield. The difference was small; both varieties gave a good net energy yield. Spring sowing may also offer the opportunity for growing an additional over-winter catch crop for spring harvest, thus increasing the overall biomass yield per hectare, with both crops being potential digester feedstocks.

7 CFR 760.811 - Rates and yields; calculating payments.

Code of Federal Regulations, 2010 CFR

2010-01-01

... from NASS or other sources approved by FSA that show there is a significant difference in yield or value based on a distinct and separate end use of the crop. Despite potential differences in yield or...

7 CFR 760.811 - Rates and yields; calculating payments.

Code of Federal Regulations, 2012 CFR

2012-01-01

... from NASS or other sources approved by FSA that show there is a significant difference in yield or value based on a distinct and separate end use of the crop. Despite potential differences in yield or...

7 CFR 760.811 - Rates and yields; calculating payments.

Code of Federal Regulations, 2011 CFR

2011-01-01

... from NASS or other sources approved by FSA that show there is a significant difference in yield or value based on a distinct and separate end use of the crop. Despite potential differences in yield or...

7 CFR 760.811 - Rates and yields; calculating payments.

Code of Federal Regulations, 2013 CFR

2013-01-01

... from NASS or other sources approved by FSA that show there is a significant difference in yield or value based on a distinct and separate end use of the crop. Despite potential differences in yield or...

7 CFR 760.811 - Rates and yields; calculating payments.

Code of Federal Regulations, 2014 CFR

2014-01-01

... from NASS or other sources approved by FSA that show there is a significant difference in yield or value based on a distinct and separate end use of the crop. Despite potential differences in yield or...

LACIE: Wheat yield models for the USSR

NASA Technical Reports Server (NTRS)

Sakamoto, C. M.; Leduc, S. K.

1977-01-01

A quantitative model determining the relationship between weather conditions and wheat yield in the U.S.S.R. was studied to provide early reliable forecasts on the size of the U.S.S.R. wheat harvest. Separate models are developed for spring wheat and for winter. Differences in yield potential and responses to stress conditions and cultural improvements necessitate models for each class.

Biomass production of herbaceous energy crops in the United States: Field trial results and yield potential maps from the multiyear regional feedstock partnership

USDA-ARS?s Scientific Manuscript database

Current knowledge of yield potential and best agronomic management practices for perennial bioenergy grasses is primarily derived from small-scale and short-term studies, yet these studies inform policy at the national scale. In an effort to learn more about how bioenergy grasses perform at the farm...

Maize yield gaps caused by non-controllable, agronomic, and socioeconomic factors in a changing climate of Northeast China.

PubMed

Liu, Zhijuan; Yang, Xiaoguang; Lin, Xiaomao; Hubbard, Kenneth G; Lv, Shuo; Wang, Jing

2016-01-15

Closing the gap between current and potential yields is one means of increasing agricultural production to feed the globally increasing population. Therefore, investigation of the geographic patterns, trends and causes of crop yield gaps is essential to identifying where yields might be increased and quantifying the contributions of yield-limiting factors that may provide us potentials to enhance crop productivity. In this study, the changes in potential yields, attainable yields, potential farmers' yields, and actual farmers' yields during the past five decades in Northeast China (NEC) were investigated. Additionally the yield gaps caused by non-controllable, agronomic, and socioeconomic factors were determined. Over the period 1961 to 2010 the estimated regional area-weighted mean maize potential yield, attainable yield, and potential farmers' yield were approximately 12.3 t ha(-1), 11.5 t ha(-1), and 6.4 t ha(-1) which showed a decreasing tendency. The actual farmers' yield over NEC was 4.5 t ha(-1), and showed a tendency to increase (p<0.01) by 1.27 t ha(-1) per decade. The regional mean total yield gap (YGt), weighted by the area in each county dedicated to maize crop, was 64% of potential yield. Moreover, 8, 40, and 16% reductions in potential yields were due to non-controllable factors (YGI), agronomic factors (YGII), and socioeconomic factors (YGIII), respectively. Therefore, the exploitable yield gap, considered here as the difference between the potential yield and what one can expect considering non-controllable factors (i.e. YGt-YGI), of maize in NEC was about 56%. The regional area-weighted averages of YGt, and YGIII were found to have significant decreases of 11.0, and 10.7% per decade. At the time horizon 2010, the exploitable yield gaps were estimated to equal 36% of potential yield. This led to the conclusion that the yield gap could be deeply reduced by improving local agronomic management and controlling socioeconomic factors. Copyright © 2015

Yield prediction by analysis of multispectral scanner data

NASA Technical Reports Server (NTRS)

Colwell, J. E.; Suits, G. H.

1975-01-01

A preliminary model describing the growth and grain yield of wheat was developed. The modeled growth characteristics of the wheat crop were used to compute wheat canopy reflectance using a model of vegetation canopy reflectance. The modeled reflectance characteristics were compared with the corresponding growth characteristics and grain yield in order to infer their relationships. It appears that periodic wheat canopy reflectance characteristics potentially derivable from earth satellites will be useful in forecasting wheat grain yield.

Modelling Bambara Groundnut Yield in Southern Africa: Towards a Climate-Resilient Future

NASA Technical Reports Server (NTRS)

Karunaratne, A. S.; Walker, S.; Ruane, A. C.

2015-01-01

Current agriculture depends on a few major species grown as monocultures that are supported by global research underpinning current productivity. However, many hundreds of alternative crops have the potential to meet real world challenges by sustaining humanity, diversifying agricultural systems for food and nutritional security, and especially responding to climate change through their resilience to certain climate conditions. Bambara groundnut (Vigna subterranea (L.) Verdc.), an underutilised African legume, is an exemplar crop for climate resilience. Predicted yield performances of Bambara groundnut by AquaCrop (a crop-water productivity model) were evaluated for baseline (1980-2009) and mid-century climates (2040-2069) under 20 downscaled Global Climate Models (CMIP5-RCP8.5), as well as for climate sensitivities (AgMIPC3MP) across 3 locations in Southern Africa (Botswana, South Africa, Namibia). Different land - races of Bambara groundnut originating from various semi-arid African locations showed diverse yield performances with diverse sensitivities to climate. S19 originating from hot-dry conditions in Namibia has greater future yield potential compared to the Swaziland landrace Uniswa Red-UN across study sites. South Africa has the lowest yield under the current climate, indicating positive future yield trends. Namibia reported the highest baseline yield at optimum current temperatures, indicating less yield potential in future climates. Bambara groundnut shows positive yield potential at temperatures of up to 31degC, with further warming pushing yields down. Thus, many regions in Southern Africa can utilize Bambara groundnut successfully in the coming decades. This modelling exercise supports decisions on genotypic suitability for present and future climates at specific locations.

Estimates of spatial and temporal variation of energy crops biomass yields in the US

NASA Astrophysics Data System (ADS)

Song, Y.; Jain, A. K.; Landuyt, W.; Kheshgi, H. S.

2013-12-01

Perennial grasses, such as switchgrass (Panicum viragatum) and Miscanthus (Miscanthus x giganteus) have been identified for potential use as biomass feedstocks in the US. Current research on perennial grass biomass production has been evaluated on small-scale plots. However, the extent to which this potential can be realized at a landscape-scale will depend on the biophysical potential to grow these grasses with minimum possible amount of land that needs to be diverted from food to fuel production. To assess this potential three questions about the biomass yield for these grasses need to be answered: (1) how the yields for different grasses are varied spatially and temporally across the US; (2) whether the yields are temporally stable or not; and (3) how the spatial and temporal trends in yields of these perennial grasses are controlled by limiting factors, including soil type, water availability, climate, and crop varieties. To answer these questions, the growth processes of the perennial grasses are implemented into a coupled biophysical, physiological and biogeochemical model (ISAM). The model has been applied to quantitatively investigate the spatial and temporal trends in biomass yields for over the period 1980 -2010 in the US. The bioenergy grasses considered in this study include Miscanthus, Cave-in-Rock switchgrass and Alamo switchgrass. The effects of climate, soil and topography on the spatial and temporal trends of biomass yields are quantitatively analyzed using principal component analysis and GIS based geographically weighted regression. The spatial temporal trend results are evaluated further to classify each part of the US into four homogeneous potential yield zones: high and stable yield zone (HS), high but unstable yield zone (HU), low and stable yield zone (LS) and low but unstable yield zone (LU). Our preliminary results indicate that the yields for perennial grasses among different zones are strongly related to the different controlling factors

Estimating yield gaps at the cropping system level.

PubMed

Guilpart, Nicolas; Grassini, Patricio; Sadras, Victor O; Timsina, Jagadish; Cassman, Kenneth G

2017-05-01

Yield gap analyses of individual crops have been used to estimate opportunities for increasing crop production at local to global scales, thus providing information crucial to food security. However, increases in crop production can also be achieved by improving cropping system yield through modification of spatial and temporal arrangement of individual crops. In this paper we define the cropping system yield potential as the output from the combination of crops that gives the highest energy yield per unit of land and time, and the cropping system yield gap as the difference between actual energy yield of an existing cropping system and the cropping system yield potential. Then, we provide a framework to identify alternative cropping systems which can be evaluated against the current ones. A proof-of-concept is provided with irrigated rice-maize systems at four locations in Bangladesh that represent a range of climatic conditions in that country. The proposed framework identified (i) realistic alternative cropping systems at each location, and (ii) two locations where expected improvements in crop production from changes in cropping intensity (number of crops per year) were 43% to 64% higher than from improving the management of individual crops within the current cropping systems. The proposed framework provides a tool to help assess food production capacity of new systems ( e.g. with increased cropping intensity) arising from climate change, and assess resource requirements (water and N) and associated environmental footprint per unit of land and production of these new systems. By expanding yield gap analysis from individual crops to the cropping system level and applying it to new systems, this framework could also be helpful to bridge the gap between yield gap analysis and cropping/farming system design.

A Priori Estimation of Organic Reaction Yields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Emami, Fateme S.; Vahid, Amir; Wylie, Elizabeth K.

2015-07-21

A thermodynamically guided calculation of free energies of substrate and product molecules allows for the estimation of the yields of organic reactions. The non-ideality of the system and the solvent effects are taken into account through the activity coefficients calculated at the molecular level by perturbed-chain statistical associating fluid theory (PC-SAFT). The model is iteratively trained using a diverse set of reactions with yields that have been reported previously. This trained model can then estimate a priori the yields of reactions not included in the training set with an accuracy of ca. ±15 %. This ability has the potential tomore » translate into significant economic savings through the selection and then execution of only those reactions that can proceed in good yields.« less

Norepinephrine reuptake inhibition promotes mobilization in mice: potential impact to rescue low stem cell yields

PubMed Central

Lucas, Daniel; Bruns, Ingmar; Battista, Michela; Mendez-Ferrer, Simon; Magnon, Claire; Kunisaki, Yuya

2012-01-01

The mechanisms mediating hematopoietic stem and progenitor cell (HSPC) mobilization by G-CSF are complex. We have found previously that G-CSF–enforced mobilization is controlled by peripheral sympathetic nerves via norepinephrine (NE) signaling. In the present study, we show that G-CSF likely alters sympathetic tone directly and that methods to increase adrenergic activity in the BM microenvironment enhance progenitor mobilization. Peripheral sympathetic nerve neurons express the G-CSF receptor and ex vivo stimulation of peripheral sympathetic nerve neurons with G-CSF reduced NE reuptake significantly, suggesting that G-CSF potentiates the sympathetic tone by increasing NE availability. Based on these data, we investigated the NE reuptake inhibitor desipramine in HSPC mobilization. Whereas desipramine did not by itself elicit circulating HSPCs, it increased G-CSF–triggered mobilization efficiency significantly and rescued mobilization in a model mimicking “poor mobilizers.” Therefore, these data suggest that blockade of NE reuptake may be a novel therapeutic target to increase stem cell yield in patients. PMID:22422821

Hydrogeologic terranes and potential yield of water to wells in the Valley and Ridge Physiographic Province in the eastern and southeastern United States

USGS Publications Warehouse

Hollyday, E.F.; Hileman, G.E.

1996-01-01

elsewhere. Estimates of potential yields to public and industrial supply wells were calculated from specific-capacity data for most-productive wells, which have casing diameter of 7 in. or more, discharge water primarily for public or industrial supply, and are in a valley. Median constant drawdowns, calculated from reported drawdowns, were assumed to be between 10 and 90 ft for wells completed in each of the five hydrogeologic terranes, and well-entrance losses were assumed to be negligible. Estimated interquartile ranges in potential yields to 412 mostproductive wells in the five hydrogeologic terranes were 170 to 580 gal/min, alluvium; 210 to 1,400 gal/min, dolomite; 80 to 720 gal/min, limestone; 65 to 850 gal/min, argillaceous carbonate rock; and 70 to 280 gal/min, siliciclastic rock.

Are GM Crops for Yield and Resilience Possible?

PubMed

Paul, Matthew J; Nuccio, Michael L; Basu, Shib Sankar

2018-01-01

Crop yield improvements need to accelerate to avoid future food insecurity. Outside Europe, genetically modified (GM) crops for herbicide- and insect-resistance have been transformative in agriculture; other traits have also come to market. However, GM of yield potential and stress resilience has yet to impact on food security. Genes have been identified for yield such as grain number, size, leaf growth, resource allocation, and signaling for drought tolerance, but there is only one commercialized drought-tolerant GM variety. For GM and genome editing to impact on yield and resilience there is a need to understand yield-determining processes in a cell and developmental context combined with evaluation in the grower environment. We highlight a sugar signaling mechanism as a paradigm for this approach. Copyright © 2017 Elsevier Ltd. All rights reserved.

Brazilian Soybean Yields and Yield Gaps Vary with Farm Size

NASA Astrophysics Data System (ADS)

Jeffries, G. R.; Cohn, A.; Griffin, T. S.; Bragança, A.

2017-12-01

Understanding the farm size-specific characteristics of crop yields and yield gaps may help to improve yields by enabling better targeting of technical assistance and agricultural development programs. Linking remote sensing-based yield estimates with property boundaries provides a novel view of the relationship between farm size and yield structure (yield magnitude, gaps, and stability over time). A growing literature documents variations in yield gaps, but largely ignores the role of farm size as a factor shaping yield structure. Research on the inverse farm size-productivity relationship (IR) theory - that small farms are more productive than large ones all else equal - has documented that yield magnitude may vary by farm size, but has not considered other yield structure characteristics. We examined farm size - yield structure relationships for soybeans in Brazil for years 2001-2015. Using out-of-sample soybean yield predictions from a statistical model, we documented 1) gaps between the 95th percentile of attained yields and mean yields within counties and individual fields, and 2) yield stability defined as the standard deviation of time-detrended yields at given locations. We found a direct relationship between soy yields and farm size at the national level, while the strength and the sign of the relationship varied by region. Soybean yield gaps were found to be inversely related to farm size metrics, even when yields were only compared to farms of similar size. The relationship between farm size and yield stability was nonlinear, with mid-sized farms having the most stable yields. The work suggests that farm size is an important factor in understanding yield structure and that opportunities for improving soy yields in Brazil are greatest among smaller farms.

Soil salinity and matric potential interaction on water use, water use efficiency and yield response factor of bean and wheat.

PubMed

Khataar, Mahnaz; Mohhamadi, Mohammad Hossien; Shabani, Farzin

2018-02-08

We studied the effects of soil matric potential and salinity on the water use (WU), water use efficiency (WUE) and yield response factor (Ky), for wheat (Triticum aestivum cv. Mahdavi) and bean (Phaseoulus vulgaris cv. COS16) in sandy loam and clay loam soils under greenhouse conditions. Results showed that aeration porosity is the predominant factor controlling WU, WUE, Ky and shoot biomass (Bs) at high soil water potentials. As matric potential was decreased, soil aeration improved, with Bs, WU and Ky reaching maximum value at -6 to -10 kPa, under all salinities. Wheat WUE remained almost unchanged by reduction of matric potential under low salinities (EC ≤ 8 dSm -1 ), but increased under higher salinities (EC ≥ 8 dSm -1 ), as did bean WUE at all salinities, as matric potential decreased to -33 kPa. Wheat WUE exceeds that of bean in both sandy loam and clay loam soils. WUE of both plants increased with higher shoot/root ratio and a high correlation coefficient exists between them. Results showed that salinity decreases all parameters, particularly at high potentials (h = -2 kPa), and amplifies the effects of waterlogging. Further, we observed a strong relationship between transpiration (T) and root respiration (Rr) for all experiments.

Groundwater subsidies and penalties to corn yield

NASA Astrophysics Data System (ADS)

Zipper, S. C.; Booth, E.; Loheide, S. P.

2013-12-01

Proper water management is critical to closing yield gaps (observed yield below potential yield) as global populations continue to expand. However, the impacts of shallow groundwater on crop production and surface processes are poorly understood. The presence of groundwater within or just below the root zone has the potential to cause (via oxygen stress in poorly drained soils) or eliminate (via water supply in dry regions) yield gaps. The additional water use by a plant in the presence of shallow groundwater, compared to free drainage conditions, is called the groundwater subsidy; the depth at which the groundwater subsidy is greatest is the optimal depth to groundwater (DTGW). In wet years or under very shallow water table conditions, the groundwater subsidy is likely to be negative due to increased oxygen stress, and can be thought of as a groundwater penalty. Understanding the spatial dynamics of groundwater subsidies/penalties and how they interact with weather is critical to making sustainable agricultural and land-use decisions under a range of potential climates. Here, we examine patterns of groundwater subsidies and penalties in two commercial cornfields in the Yahara River Watershed, an urbanizing agricultural watershed in south-central Wisconsin. Water table levels are generally rising in the region due to a long-term trend of increasing precipitation over the last several decades. Biophysical indicators tracked throughout both the 2012 and 2013 growing seasons show a strong response to variable groundwater levels on a field scale. Sections of the field with optimal DTGW exhibit consistently higher stomatal conductance rates, taller canopies and higher leaf area index, higher ET rates, and higher pollination success rates. Patterns in these biophysical lines of evidence allow us to pinpoint specific periods within the growing season that plants were experiencing either oxygen or water stress. Most importantly, groundwater subsidies and penalties are

Complete pathological response (ypT0N0M0) after preoperative chemotherapy alone for stage IV rectal cancer.

PubMed

Naiken, Surennaidoo P; Toso, Christian; Rubbia-Brandt, Laura; Thomopoulos, Theodoros; Roth, Arnaud; Mentha, Gilles; Morel, Philippe; Gervaz, Pascal

2014-01-17

Complete pathological response occurs in 10-20% of patients with rectal cancer who are treated with neoadjuvant chemoradiation therapy prior to pelvic surgery. The possibility that complete pathological response of rectal cancer can also occur with neoadjuvant chemotherapy alone (without radiation) is an intriguing hypothesis. A 66-year old man presented an adenocarcinoma of the rectum with nine liver metastases (T3N1M1). He was included in a reverse treatment, aiming at first downsizing the liver metastases by chemotherapy, and subsequently performing the liver surgery prior to the rectum resection. The neoadjuvant chemotherapy consisted in a combination of oxaliplatin, 5-FU, irinotecan, leucovorin and bevacizumab (OCFL-B). After a right portal embolization, an extended right liver lobectomy was performed. On the final histopathological analysis, all lesions were fibrotic, devoid of any viable cancer cells. One month after liver surgery, the rectoscopic examination showed a near-total response of the primary rectal adenocarcinoma, which convinced the colorectal surgeon to perform the low anterior resection without preoperative radiation therapy. Macroscopically, a fibrous scar was observed at the level of the previously documented tumour, and the histological examination of the surgical specimen did not reveal any malignant cells in the rectal wall as well as in the mesorectum. All 15 resected lymph nodes were free of tumour, and the final tumour stage was ypT0N0M0. Clinical outcome was excellent, and the patient is currently alive 5 years after the first surgery without evidence of recurrence. The presented patient with stage IV rectal cancer and liver metastases was in a unique situation linked to its inclusion in a reversed treatment and the use of neoadjuvant chemotherapy alone. The observed achievement of a complete pathological response after chemotherapy should promote the design of prospective randomized studies to evaluate the benefits of chemotherapy

Climate Effects on Corn Yield in Missouri(.

NASA Astrophysics Data System (ADS)

Hu, Qi; Buyanovsky, Gregory

2003-11-01

Understanding climate effects on crop yield has been a continuous endeavor aiming at improving farming technology and management strategy, minimizing negative climate effects, and maximizing positive climate effects on yield. Many studies have examined climate effects on corn yield in different regions of the United States. However, most of those studies used yield and climate records that were shorter than 10 years and were for different years and localities. Although results of those studies showed various influences of climate on corn yield, they could be time specific and have been difficult to use for deriving a comprehensive understanding of climate effects on corn yield. In this study, climate effects on corn yield in central Missouri are examined using unique long-term (1895 1998) datasets of both corn yield and climate. Major results show that the climate effects on corn yield can only be explained by within-season variations in rainfall and temperature and cannot be distinguished by average growing-season conditions. Moreover, the growing-season distributions of rainfall and temperature for high-yield years are characterized by less rainfall and warmer temperature in the planting period, a rapid increase in rainfall, and more rainfall and warmer temperatures during germination and emergence. More rainfall and cooler-than-average temperatures are key features in the anthesis and kernel-filling periods from June through August, followed by less rainfall and warmer temperatures during the September and early October ripening time. Opposite variations in rainfall and temperature in the growing season correspond to low yield. Potential applications of these results in understanding how climate change may affect corn yield in the region also are discussed.

Development of Cu-bearing bake-hardenable steel sheets for automotive exposed panels

NASA Astrophysics Data System (ADS)

Hong, Moon-Hi; Cho, Noi-Ha; Kim, Sung-Il; Kwon, Ohjoon; Lim, Sung-Hwan; Moon, Won-Jin

2010-12-01

Recently, newly developed bake-hardenable (BH) steel sheets strengthened by copper sulfide (CuS) have been successfully employed in commercial production lines that supply automotive outer panels. The metallurgical concepts governing fabrication of these new BH steel sheets require keeping carbon content as low as 0.0015 wt.% without any additional amount of titanium and/or niobium for solute carbon scavenging. The role of CuS precipitates has turned out to raise the yield strength acting as a barrier against dislocation movement. In this paper, we studied the effects of chemical compositions and manufacturing process variables on the microstructure and mechanical properties of newly developed BH steel sheets. We found that the control of carbon and nitrogen showed a good balance between bake-hardenability (BH) and yield point elongation (YP-El). We identified the crystallographic relationship between the nano-size CuS precipitates and the ferrite matrix of (001)sulfide//(001)α-Fe and [001]sulfide//[001]α-Fe. We also found that the BH and YP-El were affected by the formation of aluminium nitride (AlN) and the annealing temperature.

Yield and Economic Responses of Peanut to Crop Rotation Sequence

USDA-ARS?s Scientific Manuscript database

Proper crop rotation is essential to maintaining high peanut yield and quality. However, the economic considerations of maintaining or altering crop rotation sequences must incorporate the commodity prices, production costs, and yield responses of all crops in, or potentially in, the crop rotation ...

An assessment of irrigation needs and crop yield for the United States under potential climate changes

USGS Publications Warehouse

Brumbelow, Kelly; Georgakakos, Aris P.

2000-01-01

Past assessments of climate change on U.S. agriculture have mostly focused on changes in crop yield. Few studies have included the entire conterminous U.S., and few studies have assessed changing irrigation requirements. None have included the effects of changing soil moisture characteristics as determined by changing climatic forcing. This study assesses changes in irrigation requirements and crop yields for five crops in the areas of the U.S. where they have traditionally been grown. Physiologically-based crop models are used to incorporate inputs of climate, soils, agricultural management, and drought stress tolerance. Soil moisture values from a macroscale hydrologic model run under a future climate scenario are used to initialize soil moisture content at the beginning of each growing season. Historical crop yield data is used to calibrate model parameters and determine locally acceptable drought stress as a management parameter. Changes in irrigation demand and crop yield are assessed for both means and extremes by comparing results for atmospheric forcing close to the present climate with those for a future climate scenario. Assessments using the Canadian Center for Climate Modeling and Analysis General Circulation Model (CGCM1) indicate greater irrigation demands in the southern U.S. and decreased irrigation demands in the northern and western U.S. Crop yields typically increase except for winter wheat in the southern U.S. and corn. Variability in both irrigation demands and crop yields increases in most cases. Assessment results for the CGCM1 climate scenario are compared to those for the Hadley Centre for Climate Prediction and Research GCM (HadCM2) scenario for southwestern Georgia. The comparison shows significant differences in irrigation and yield trends, both in magnitude and direction. The differences reflect the high forecast uncertainty of current GCMs. Nonetheless, both GCMs indicate higher variability in future climatic forcing and, consequently

A direct comparison of exoEarth yields for starshades and coronagraphs

NASA Astrophysics Data System (ADS)

Stark, Christopher C.; Cady, Eric J.; Clampin, Mark; Domagal-Goldman, Shawn; Lisman, Doug; Mandell, Avi M.; McElwain, Michael W.; Roberge, Aki; Robinson, Tyler D.; Savransky, Dmitry; Shaklan, Stuart B.; Stapelfeldt, Karl R.

2016-07-01

The scale and design of a future mission capable of directly imaging extrasolar planets will be influenced by the detectable number (yield) of potentially Earth-like planets. Currently, coronagraphs and starshades are being considered as instruments for such a mission. We will use a novel code to estimate and compare the yields for starshade- and coronagraph-based missions. We will show yield scaling relationships for each instrument and discuss the impact of astrophysical and instrumental noise on yields. Although the absolute yields are dependent on several yet-unknown parameters, we will present several limiting cases allowing us to bound the yield comparison.

Global warming potential and greenhouse gas intensity in rice agriculture driven by high yields and nitrogen use efficiency

NASA Astrophysics Data System (ADS)

Zhang, Xiaoxu; Xu, Xin; Liu, Yinglie; Wang, Jinyang; Xiong, Zhengqin

2016-05-01

Our understanding of how global warming potential (GWP) and greenhouse gas intensity (GHGI) is affected by management practices aimed at food security with respect to rice agriculture remains limited. In the present study, a field experiment was conducted in China to evaluate the effects of integrated soil-crop system management (ISSM) on GWP and GHGI after accounting for carbon dioxide (CO2) equivalent emissions from all sources, including methane (CH4) and nitrous oxide (N2O) emissions, agrochemical inputs and farm operations and sinks (i.e., soil organic carbon sequestration). The ISSM mainly consisted of different nitrogen (N) fertilization rates and split, manure, Zn and Na2SiO3 fertilization and planting density for the improvement of rice yield and agronomic nitrogen use efficiency (NUE). Four ISSM scenarios consisting of different chemical N rates relative to the local farmers' practice (FP) rate were carried out, namely, ISSM-N1 (25 % reduction), ISSM-N2 (10 % reduction), ISSM-N3 (FP rate) and ISSM-N4 (25 % increase). The results showed that compared with the FP, the four ISSM scenarios significantly increased the rice yields by 10, 16, 28 and 41 % and the agronomic NUE by 75, 67, 35 and 40 %, respectively. In addition, compared with the FP, the ISSM-N1 and ISSM-N2 scenarios significantly reduced the GHGI by 14 and 18 %, respectively, despite similar GWPs. The ISSM-N3 and ISSM-N4 scenarios remarkably increased the GWP and GHGI by an average of 69 and 39 %, respectively. In conclusion, the ISSM strategies are promising for both food security and environmental protection, and the ISSM scenario of ISSM-N2 is the optimal strategy to realize high yields and high NUE together with low environmental impacts for this agricultural rice field.

Quantum chemical exploration of the intramolecular hydrogen bond interaction in 2-thiazol-2-yl-phenol and 2-benzothiazol-2-yl-phenol in the context of excited-state intramolecular proton transfer: A focus on the covalency in hydrogen bond

NASA Astrophysics Data System (ADS)

Paul, Bijan Kumar; Ganguly, Aniruddha; Guchhait, Nikhil

2014-10-01

The present work demonstrates a computational exploration of the intramolecular H-bond (IMHB) interaction in two model heterocyclic compounds - 2-thiazol-2-yl-phenol (2T2YP) and 2-benzothiazol-2-yl-phenol (2B2YP) by meticulous application of various quantum chemical tools. Major emphasis is rendered on the analysis of IMHB interaction by calculation of electron density ρ(r) and Laplacian ∇2ρ(r) at the bond critical point using the Atoms-In-Molecule methodology. Topological features based on ρ(r) suggest that at equilibrium geometry the IMHB interaction develops certain characteristics typical of a covalent interaction. The interplay between aromaticity and Resonance-Assisted H-Bond (RAHB) has also been discussed using both geometrical and magnetic criteria. The occurrence of IMHB interaction in 2T2YP and 2B2YP has also been criticized under the provision of the Natural Bond Orbital (NBO) analysis. The ESIPT phenomenon in the molecular systems is also critically addressed on the lexicon of potential energy surface (PES) analysis.

The yield and decay coefficients of exoelectrogenic bacteria in bioelectrochemical systems.

PubMed

Wilson, Erica L; Kim, Younggy

2016-05-01

In conventional wastewater treatment, waste sludge management and disposal contribute the major cost for wastewater treatment. Bioelectrochemical systems, as a potential alternative for future wastewater treatment and resources recovery, are expected to produce small amounts of waste sludge because exoelectrogenic bacteria grow on anaerobic respiration and form highly populated biofilms on bioanode surfaces. While waste sludge production is governed by the yield and decay coefficient, none of previous studies have quantified these kinetic constants for exoelectrogenic bacteria. For yield coefficient estimation, we modified McCarty's free energy-based model by using the bioanode potential for the free energy of the electron acceptor reaction. The estimated true yield coefficient ranged 0.1 to 0.3 g-VSS (volatile suspended solids) g-COD(-1) (chemical oxygen demand), which is similar to that of most anaerobic microorganisms. The yield coefficient was sensitively affected by the bioanode potential and pH while the substrate and bicarbonate concentrations had relatively minor effects on the yield coefficient. In lab-scale experiments using microbial electrolysis cells, the observed yield coefficient (including the effect of cell decay) was found to be 0.020 ± 0.008 g-VSS g-COD(-1), which is an order of magnitude smaller than the theoretical estimation. Based on the difference between the theoretical and experimental results, the decay coefficient was approximated to be 0.013 ± 0.002 d(-1). These findings indicate that bioelectrochemical systems have potential for future wastewater treatment with reduced waste sludge as well as for resources recovery. Also, the found kinetic information will allow accurate estimation of wastewater treatment performance in bioelectrochemical systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis and characterization of a NaSICON series with general formula Na 2.8Zr 2-ySi 1.8-4yP 1.2+4yO 12 (0⩽ y⩽0.45)

NASA Astrophysics Data System (ADS)

Essoumhi, A.; Favotto, C.; Mansori, M.; Satre, P.

2004-12-01

In this work, we present the synthesis and the characterization of ionic conducting ceramics of NaSICON-type (Natrium super ionic conductor). The properties of this ceramic make it suitable for use in electrochemical devices. These solid electrolytes can be used as sensors for application in the manufacturing of potentiometric gas sensors, for the detection of pollutant emissions and for environment control. The family of NaSICON that we studied has as a general formula Na 2.8Zr 2-ySi 1.8-4yP 1.2+4yO 12 with 0⩽ y⩽0.45. The various compositions were synthesized by produced using the sol-gel method. The electric properties of these compositions were carried out by impedance spectroscopy. The results highlight the good conductivity of the Na 2.8Zr 1.775Si 0.9P 2.1O 12 composition.

Using satellite data to identify the causes of and potential solutions for yield gaps in India’s Wheat Belt

NASA Astrophysics Data System (ADS)

Jain, M.; Singh, Balwinder; Srivastava, A. A. K.; Malik, R. K.; McDonald, A. J.; Lobell, D. B.

2017-09-01

Food security will be increasingly challenged by climate change, natural resource degradation, and population growth. Wheat yields, in particular, have already stagnated in many regions and will be further affected by warming temperatures. Despite these challenges, wheat yields can be increased by improving management practices in regions with existing yield gaps. To identify the magnitude and causes of current yield gaps in India, one of the largest wheat producers globally, we produced 30 meter resolution yield maps from 2001 to 2015 across the Indo-Gangetic Plains (IGP), the nation’s main wheat belt. Yield maps were derived using a new method that translates satellite vegetation indices to yield estimates using crop model simulations, bypassing the need for ground calibration data. This is one of the first attempts to apply this method to a smallholder agriculture system, where ground calibration data are rarely available. We find that yields can be increased by 11% on average and up to 32% in the eastern IGP by improving management to current best practices within a given district. Additionally, if current best practices from the highest-yielding state of Punjab are implemented in the eastern IGP, yields could increase by almost 110%. Considering the factors that most influence yields, later sow dates and warmer temperatures are most associated with low yields across the IGP. This suggests that strategies to reduce the negative effects of heat stress, like earlier sowing and planting heat-tolerant wheat varieties, are critical to increasing wheat yields in this globally-important agricultural region.

Developing and Evaluating JIApp: Acceptability and Usability of a Smartphone App System to Improve Self-Management in Young People With Juvenile Idiopathic Arthritis

PubMed Central

Beste, Dominik; Chaplin, Hema; Varakliotis, Socrates; Suffield, Linda; Josephs, Francesca; Sen, Debajit; Wedderburn, Lucy R; Ioannou, Yiannakis; Hailes, Stephen; Eleftheriou, Despina

2017-01-01

Background Flare-ups in juvenile idiopathic arthritis (JIA) are characterized by joint pain and swelling and often accompanied with fatigue, negative emotions, and reduced participation in activities. To minimize the impact of JIA on the physical and psychosocial development and well-being of young people (YP), it is essential to regularly monitor disease activity and side effects, as well as to support self-management such as adherence to treatment plans and engagement in general health-promoting behaviors. Smartphone technology has the potential to engage YP with their health care through convenient self-monitoring and easy access to information. In addition, having a more accurate summary of self-reported fluctuations in symptoms, behaviors, and psychosocial problems can help both YP and health care professionals (HCPs) better understand the patient’s condition, identify barriers to self-management, and assess treatment effectiveness and additional health care needs. No comprehensive smartphone app has yet been developed in collaboration with YP with JIA, their parents, and HCPs involved in their care. Objectives The objective of this study was to design, develop, and evaluate the acceptability and usability of JIApp, a self-management smartphone app system for YP with JIA and HCPs. Methods We used a qualitative, user-centered design approach involving YP, parents, and HCPs from the rheumatology team. The study was conducted in three phases: (1) phase I focused on developing consensus on the features, content, and design of the app; (2) phase II was used for further refining and evaluating the app prototype; and (3) phase III focused on usability testing of the app. The interview transcripts were analyzed using qualitative content analysis. Results A total of 29 YP (aged 10-23, median age 17) with JIA, 7 parents, and 21 HCPs were interviewed. Major themes identified as the ones that helped inform app development in phase I were: (1) remote monitoring of

Irrigation offsets wheat yield reductions from warming temperatures

NASA Astrophysics Data System (ADS)

Tack, Jesse; Barkley, Andrew; Hendricks, Nathan

2017-11-01

Temperature increases due to climate change are expected to cause substantial reductions in global wheat yields. However, uncertainty remains regarding the potential role for irrigation as an adaptation strategy to offset heat impacts. Here we utilize over 7000 observations spanning eleven Kansas field-trial locations, 180 varieties, and 29 years to show that irrigation significantly reduces the negative impact of warming temperatures on winter wheat yields. Dryland wheat yields are estimated to decrease about eight percent for every one-degree Celsius increase in temperature, yet irrigation completely offsets this negative impact in our sample. As in previous studies, we find that important interactions exist between heat stress and precipitation for dryland production. Here, uniquely, we observe both dryland and irrigated trials side-by-side at the same locations and find that precipitation does not provide the same reduction in heat stress as irrigation. This is likely to be because the timing, intensity, and volume of water applications influence wheat yields, so the ability to irrigate—rather than relying on rainfall alone—has a stronger influence on heat stress. We find evidence of extensive differences of water-deficit stress impacts across varieties. This provides some evidence of the potential for adapting to hotter and drier climate conditions using optimal variety selection. Overall, our results highlight the critical role of water management for future global food security. Water scarcity not only reduces crop yields through water-deficit stress, but also amplifies the negative effects of warming temperatures.

Biochar boosts tropical but not temperate crop yields

NASA Astrophysics Data System (ADS)

Jeffery, Simon; Abalos, Diego; Prodana, Marija; Catarina Bastos, Ana; van Groenigen, Jan Willem; Hungate, Bruce A.; Verheijen, Frank

2017-05-01

Applying biochar to soil is thought to have multiple benefits, from helping mitigate climate change [1, 2], to managing waste [3] to conserving soil [4]. Biochar is also widely assumed to boost crop yield [5, 6], but there is controversy regarding the extent and cause of any yield benefit [7]. Here we use a global-scale meta-analysis to show that biochar has, on average, no effect on crop yield in temperate latitudes, yet elicits a 25% average increase in yield in the tropics. In the tropics, biochar increased yield through liming and fertilization, consistent with the low soil pH, low fertility, and low fertilizer inputs typical of arable tropical soils. We also found that, in tropical soils, high-nutrient biochar inputs stimulated yield substantially more than low-nutrient biochar, further supporting the role of nutrient fertilization in the observed yield stimulation. In contrast, arable soils in temperate regions are moderate in pH, higher in fertility, and generally receive higher fertilizer inputs, leaving little room for additional benefits from biochar. Our findings demonstrate that the yield-stimulating effects of biochar are not universal, but may especially benefit agriculture in low-nutrient, acidic soils in the tropics. Biochar management in temperate zones should focus on potential non-yield benefits such as lime and fertilizer cost savings, greenhouse gas emissions control, and other ecosystem services.

Predicted Exoplanet Yields for the HabEx Mission Concept

NASA Astrophysics Data System (ADS)

Stark, Christopher; Mennesson, Bertrand; HabEx STDT

2018-01-01

The Habitable Exoplanet Imaging Mission (HabEx) is a concept for a flagship mission to directly image and characterize extrasolar planets around nearby stars and to enable a broad range of general astrophysics. The HabEx Science and Technology Definition Team (STDT) is currently studying two architectures for HabEx. Here we summarize the exoplanet science yield of Architecture A, a 4 m monolithic off-axis telescope that uses a vortex coronagraph and a 72m external starshade occulter. We summarize the instruments' capabilities, present science goals and observation strategies, and discuss astrophysical assumptions. Using a yield optimization code, we predict the yield of potentially Earth-like extrasolar planets that could be detected, characterized, and searched for signs of habitability and/or life by HabEx. We demonstrate that HabEx could also detect and characterize a wide variety of exoplanets while searching for potentially Earth-like planets.

Quantitative Genetic Analysis Reveals Potential to Genetically Improve Fruit Yield and Drought Resistance Simultaneously in Coriander

PubMed Central

Khodadadi, Mostafa; Dehghani, Hamid; Jalali Javaran, Mokhtar

2017-01-01

Enhancing water use efficiency of coriander (Coriandrum sativum L.) is a major focus for coriander breeding to cope with drought stress. The purpose of this study was; (a) to identify the predominant mechanism(s) of drought resistance in coriander and (b) to evaluate the genetic control mechanism(s) of traits associated with drought resistance and higher fruit yield. To reach this purpose, 15 half-diallel hybrids of coriander and their six parents were evaluated under well-watered and water deficit stressed (WDS) in both glasshouse lysimetric and field conditions. The parents were selected for their different response to water deficit stress following preliminary experiments. Results revealed that the genetic control mechanism of fruit yield is complex, variable and highly affected by environment. The mode of inheritance and nature of gene action for percent assimilate partitioned to fruits were similar to those for flowering time in both well-watered and WDS conditions. A significant negative genetic linkage was found between fruit yield and percent assimilate partitioned to root, percent assimilate partitioned to shoot, root number, root diameter, root dry mass, root volume, and early flowering. Thus, to improve fruit yield under water deficit stress, selection of low values of these traits could be used. In contrast, a significant positive genetic linkage between fruit yield and percent assimilate partitioned to fruits, leaf relative water content and chlorophyll content indicate selection for high values of these traits. These secondary or surrogate traits could be selected during early segregating generations. The early ripening parent (P1; TN-59-230) contained effective genes involved in preferred percent assimilate partitioning to fruit and drought stress resistance. In conclusion, genetic improvement of fruit yield and drought resistance could be simultaneously gained in coriander when breeding for drought resistance. PMID:28473836

Corrigendum to "Sinusoidal potential cycling operation of a direct ethanol fuel cell to improving carbon dioxide yields" [J. Power Sources 268 (5 December 2014) 439-442

NASA Astrophysics Data System (ADS)

Majidi, Pasha; Pickup, Peter G.

2016-09-01

The authors regret that Equation (5) is incorrect and has resulted in errors in Fig. 4 and the efficiencies stated on p. 442. The corrected equation, figure and text are presented below. In addition, the title should be 'Sinusoidal potential cycling operation of a direct ethanol fuel cell to improve carbon dioxide yields', and the reversible cell potential quoted on p. 441 should be 1.14 V. The authors would like to apologise for any inconvenience caused.

SCS-CN based time-distributed sediment yield model

NASA Astrophysics Data System (ADS)

Tyagi, J. V.; Mishra, S. K.; Singh, Ranvir; Singh, V. P.

2008-05-01

SummaryA sediment yield model is developed to estimate the temporal rates of sediment yield from rainfall events on natural watersheds. The model utilizes the SCS-CN based infiltration model for computation of rainfall-excess rate, and the SCS-CN-inspired proportionality concept for computation of sediment-excess. For computation of sedimentographs, the sediment-excess is routed to the watershed outlet using a single linear reservoir technique. Analytical development of the model shows the ratio of the potential maximum erosion (A) to the potential maximum retention (S) of the SCS-CN method is constant for a watershed. The model is calibrated and validated on a number of events using the data of seven watersheds from India and the USA. Representative values of the A/S ratio computed for the watersheds from calibration are used for the validation of the model. The encouraging results of the proposed simple four parameter model exhibit its potential in field application.

Farmers Extension Program Effects on Yield Gap in North China Plain

NASA Astrophysics Data System (ADS)

Sum, N.; Zhao, Y.

2015-12-01

Improving crop yield of the lowest yielding smallholder farmers in developing countries is essential to both food security of the country and the farmers' livelihood. Although wheat and maize production in most developed countries have reached 80% or greater of yield potential determined by simulated models, yield gap remains high in the developing world. One of these cases is the yield gap of maize in the North China Plain (NCP), where the average farmer's yield is 41% of his or her potential yield. This large yield gap indicates opportunity to raise yields substantially by improving agronomy, especially in nutrition management, irrigation facility, and mechanization issues such as technical services. Farmers' agronomic knowledge is essential to yield performance. In order to propagate such knowledge to farmers, agricultural extension programs, especially in-the-field guidance with training programs at targeted demonstration fields, have become prevalent in China. Although traditional analyses of the effects of the extension program are done through surveys, they are limited to only one to two years and to a small area. However, the spatial analysis tool Google Earth Engine (GEE) and its extensive satellite imagery data allow for unprecedented spatial temporal analysis of yield variation. We used GEE to analyze maize yield in Quzhou county in the North China Plain from 2007 to 2013. We based our analysis on the distance from a demonstration farm plot, the source of the farmers' agronomic knowledge. Our hypothesis was that the farther the farmers' fields were from the demonstration plot, the less access they would have to the knowledge, and the less increase in yield over time. Testing this hypothesis using GEE helps us determine the effectiveness of the demonstration plot in disseminating optimal agronomic practices in addition to evaluating yield performance of the demonstration field itself. Furthermore, we can easily extend this methodology to analyze the whole

Maximized exoEarth candidate yields for starshades

NASA Astrophysics Data System (ADS)

Stark, Christopher C.; Shaklan, Stuart; Lisman, Doug; Cady, Eric; Savransky, Dmitry; Roberge, Aki; Mandell, Avi M.

2016-10-01

The design and scale of a future mission to directly image and characterize potentially Earth-like planets will be impacted, to some degree, by the expected yield of such planets. Recent efforts to increase the estimated yields, by creating observation plans optimized for the detection and characterization of Earth-twins, have focused solely on coronagraphic instruments; starshade-based missions could benefit from a similar analysis. Here we explore how to prioritize observations for a starshade given the limiting resources of both fuel and time, present analytic expressions to estimate fuel use, and provide efficient numerical techniques for maximizing the yield of starshades. We implemented these techniques to create an approximate design reference mission code for starshades and used this code to investigate how exoEarth candidate yield responds to changes in mission, instrument, and astrophysical parameters for missions with a single starshade. We find that a starshade mission operates most efficiently somewhere between the fuel- and exposuretime-limited regimes and, as a result, is less sensitive to photometric noise sources as well as parameters controlling the photon collection rate in comparison to a coronagraph. We produced optimistic yield curves for starshades, assuming our optimized observation plans are schedulable and future starshades are not thrust-limited. Given these yield curves, detecting and characterizing several dozen exoEarth candidates requires either multiple starshades or an η≳0.3.

Humoral and cellular immune response of mice challenged with Yersinia pestis antigenic preparations.

PubMed

Leal, Elida A; Moreira, Josimar D; Nunes, Fernanda F; Souza, Larissa R; Martins, Janaina M; Toledo, Vicente P C; Almeida, Alzira M P; Guimarães, Tania M P

The plague, which is an infectious disease caused by Yersinia pestis, still threatens many populations in several countries. The worldwide increase in human plague cases and the potential use of the bacteria as a biological weapon reinforce the need to study the immunity that is induced by potential vaccine candidates. To determine the immunogenicity of antigenic preparations based on the F1 protein and the total extract from Y. pestis, we assessed the role of these antigens in inducing an immune response. The immunogenicity of antigenic preparations based on the Y. pestis (YP) total extract and the Y. pestis fraction 1 capsular antigen protein (F1) was determined in Swiss-Webster mice immunized with 40μg or 20μg for each preparation. Immunophenotyping was performed by flow cytometry. Animals immunized with the YP total extract did not elicit detectable anti-F1 antibodies (Ab) in the hemaglutination/inhibition (HA/HI) test. Animals immunized with 40μg or 20μg of the F1 protein produced anti-F1 Abs, with titres ranging from 1/16 to 1/8132. The average of CD3 + -CD4 + and CD3 + -CD8 + T cells did not differ significantly between the groups. Neither YP total extract nor F1 protein induced a significant expression of IFN-γ and IL-10 in CD4 + T lymphocytes. In addition, F1 failed to induce IFN-γ expression in CD8 + T cells, unlike the YP total extract. The results showed that F1 protein is not an immunogenic T cell antigen, although the YP total extract (40μg dose) favoured CD8 + T cell-mediated cellular immunity. Copyright © 2017 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

Effects of geoengineering on crop yields

NASA Astrophysics Data System (ADS)

Pongratz, J.; Lobell, D. B.; Cao, L.; Caldeira, K.

2011-12-01

The potential of "solar radiation management" (SRM) to reduce future climate change and associated risks has been receiving significant attention in scientific and policy circles. SRM schemes aim to reduce global warming despite increasing atmospheric CO2 concentrations by diminishing the amount of solar insolation absorbed by the Earth, for example, by injecting scattering aerosols into the atmosphere. Climate models predict that SRM could fully compensate warming at the global mean in a high-CO2 world. While reduction of global warming may offset a part of the predicted negative effects of future climate change on crop yields, SRM schemes are expected to alter regional climate and to have substantial effects on climate variables other than temperature, such as precipitation. It has therefore been warned that, overall, SRM may pose a risk to food security. Assessments of benefits and risks of geoengineering are imperative, yet such assessments are only beginning to emerge; in particular, effects on global food security have not previously been assessed. Here, for the first time, we combine climate model simulations with models of crop yield responses to climate to assess large-scale changes in yields and food production under SRM. In most crop-growing regions, we find that yield losses caused by climate changes are substantially reduced under SRM as compared with a non-geoengineered doubling of atmospheric CO2. Substantial yield losses with SRM are only found for rice in high latitudes, where the limits of low temperatures are no longer alleviated. At the same time, the beneficial effect of CO2-fertilization on plant productivity remains active. Overall therefore, SRM in our models causes global crop yields to increase. We estimate the direct effects of climate and CO2 changes on crop production, and do not quantify effects of market dynamics and management changes. We note, however, that an SRM deployment would be unlikely to maintain the economic status quo, as

Estimating agricultural yield gap in Africa using MODIS NDVI dataset

NASA Astrophysics Data System (ADS)

Luan, Y.; Zhu, W.; Luo, X.; Liu, J.; Cui, X.

2013-12-01

Global agriculture has undergone a period of rapid intensification characterized as 'Green Revolution', except for Africa, which is the region most affected by unreliable food access and undernourishment. Increasing crop production will be one of the most challenges and most effectual way to mitigate food insecurity there, as Africa's agricultural yield is on a much lower level comparing to global average. In this study we characterize cropland vegetation phenology in Africa based on MODIS NDVI time series between 2000 and 2012. Cumulated NDVI is a proxy for net primary productivity and used as an indicator for evaluating the potential yield gap in Africa. It is achieved via translating the gap between optimum attainable productivity level in each classification of cropping systems and actual productivity level by the relationship of cumulated NDVI and cereal-equivalent production. The results show most of cropland area in Africa have decreasing trend in cumulated NDVI, distributing in the Nile Delta, Eastern Africa and central of semi-arid to arid savanna area, except significant positive cumulated NDVI trends are mainly found between Senegal and Benin. Using cumulated NDVI and statistics of cereal equivalent production, we find remarkable potential yield gap at the Horn of East Africa (especially in Somalia), Northern Africa (Morocco, Algeria and Tunisia). Meanwhile, countries locating at the savanna area near Sahel desert and South Africa also show significant potential, though they already have a relatively high level of productivity. Our results can help provide policy recommendation for local government or NGO to tackle food security problems by identifying zones with high potential of yield improvement.

Pseudoautosomal abnormalities in terminal AZFb+c deletions are associated with isochromosomes Yp and may lead to abnormal growth and neuropsychiatric function.

PubMed

Castro, A; Rodríguez, F; Flórez, M; López, P; Curotto, B; Martínez, D; Maturana, A; Lardone, M C; Palma, C; Mericq, V; Ebensperger, M; Cassorla, F

2017-02-01

Are copy number variations (CNVs) in the pseudoautosomal regions (PARs) frequent in subjects with Y-chromosome microdeletions and can they lead to abnormal stature and/or neuropsychiatric disorders? Only subjects diagnosed with azoospermia factor (AZF)b+c deletions spanning to the end of the Y chromosome (i.e. terminal deletions) harbor Y isochromosomes and/or cells 45,X that lead to pseudoautosomal gene CNVs, which were associated with abnormal stature and/or neuropsychiatric disorders. The microdeletions in the long arm of the Y chromosome (Yq) that include the loss of one to three AZF regions, referred to as Yq microdeletions, constitute the most important known etiological factor for primary spermatogenic failure. Recently, controversy has arisen about whether Yq microdeletions are associated with gain or loss of PAR genes, which are implicated in skeletal development and neuropsychiatric function. We studied a cohort of 42 Chilean patients with complete AZF deletions (4 AZFa, 4 AZFb, 23 AZFc, 11 AZFb+c) from a university medical center, diagnosed over a period of 15 years. The subjects underwent complete medical examinations with special attention to their stature and neuropsychiatric function. All subjects were characterized for Yq breakpoints by PCR, and for CNVs in PARs by multiplex ligation-dependent probe amplification (MLPA), followed by qPCR analysis for genes in PAR1 (SHOX and ZBED1), PAR2 (IL9R) and two single copy genes (SRY and DDX3Y, respectively located in Yp11.3 and AZFa). In addition, karyotypes revision and fluorescence in situ hybridization (FISH) for SRY and centromeric probes for X (DXZ1) and Y (DYZ3) chromosomes were performed in males affected with CNVs. We did not detect CNVs in any of the 35 AZF-deleted men with interstitial deletions (AZFa, AZFb, AZFc or AZFb+c). However, six of the seven patients with terminal AZFb+c deletions showed CNVs: two patients showed a loss and four patients showed a gain of PAR1 genes, with the expected loss

Developing young person’s Face IT: Online psychosocial support for adolescents struggling with conditions or injuries affecting their appearance

PubMed Central

Williamson, Heidi; Griffiths, Catrin; Harcourt, Diana

2015-01-01

A participatory action approach with potential users and clinical experts was employed to design and evaluate the acceptability of young person’s Face IT (YP Face IT), an online intervention incorporating cognitive behavioural therapy and social skills training for adolescents with appearance-related anxiety as a result of a visible difference. Workshops with adolescents and clinicians informed a prototype YP Face IT which underwent a usability analysis by 28 multidisciplinary health professionals and 18 adolescents, before 10 adolescents completed it at home. Acceptability data obtained online and via interview were analysed using content analysis. Participants found YP Face IT acceptable and believed it would provide much needed and easy access to psychosocial support. They requested that it should be made widely available either as a self-management tool requiring minimal supervision from a health professional or to compliment therapist-led care. PMID:28070380

Specific yield: compilation of specific yields for various materials

USGS Publications Warehouse

Johnson, A.I.

1967-01-01

Specific yield is defined as the ratio of (1) the volume of water that a saturated rock or soil will yield by gravity to (2) the total volume of the rock or soft. Specific yield is usually expressed as a percentage. The value is not definitive, because the quantity of water that will drain by gravity depends on variables such as duration of drainage, temperature, mineral composition of the water, and various physical characteristics of the rock or soil under consideration. Values of specific yields nevertheless offer a convenient means by which hydrologists can estimate the water-yielding capacities of earth materials and, as such, are very useful in hydrologic studies. The present report consists mostly of direct or modified quotations from many selected reports that present and evaluate methods for determining specific yield, limitations of those methods, and results of the determinations made on a wide variety of rock and soil materials. Although no particular values are recommended in this report, a table summarizes values of specific yield, and their averages, determined for 10 rock textures. The following is an abstract of the table. [Table

A high yield neutron target for cancer therapy

NASA Technical Reports Server (NTRS)

Alger, D. L.; Steinberg, R.

1972-01-01

A rotating target was developed that has the potential for providing an initial yield of 10 to the 13th power neutrons per second by the T(d,n)He-4 reaction, and a useable lifetime in excess of 600 hours. This yield and lifetime are indicated for a 300 Kv and 30 mA deuteron accelerator and a 30 microns thick titanium tritide film formed of the stoichiometric compound TiT2. The potential for extended lifetime is made possible by incorporating a sputtering electrode that permits use of titanium tritide thicknesses much greater than the deuteron range. The electrode is used to remove in situ depleted titanium layers to expose fresh tritide beneath. The utilization of the rotating target as a source of fast neutrons for cancer therapy is discussed.

A Remote Sensing-Derived Corn Yield Assessment Model

NASA Astrophysics Data System (ADS)

Shrestha, Ranjay Man

Agricultural studies and food security have become critical research topics due to continuous growth in human population and simultaneous shrinkage in agricultural land. In spite of modern technological advancements to improve agricultural productivity, more studies on crop yield assessments and food productivities are still necessary to fulfill the constantly increasing food demands. Besides human activities, natural disasters such as flood and drought, along with rapid climate changes, also inflect an adverse effect on food productivities. Understanding the impact of these disasters on crop yield and making early impact estimations could help planning for any national or international food crisis. Similarly, the United States Department of Agriculture (USDA) Risk Management Agency (RMA) insurance management utilizes appropriately estimated crop yield and damage assessment information to sustain farmers' practice through timely and proper compensations. Through County Agricultural Production Survey (CAPS), the USDA National Agricultural Statistical Service (NASS) uses traditional methods of field interviews and farmer-reported survey data to perform annual crop condition monitoring and production estimations at the regional and state levels. As these manual approaches of yield estimations are highly inefficient and produce very limited samples to represent the entire area, NASS requires supplemental spatial data that provides continuous and timely information on crop production and annual yield. Compared to traditional methods, remote sensing data and products offer wider spatial extent, more accurate location information, higher temporal resolution and data distribution, and lower data cost--thus providing a complementary option for estimation of crop yield information. Remote sensing derived vegetation indices such as Normalized Difference Vegetation Index (NDVI) provide measurable statistics of potential crop growth based on the spectral reflectance and could

Dimension yields from yellow-poplar lumber

Treesearch

R. C. Gilmore; J. D. Danielson

1984-01-01

The available supply of yellow poplar (Liriodendron tulipifera L.), its potential for new uses, and its continuing importance to the furniture industry have created a need to accumulate additional information about this species. As an aid to better utilization of this species, charts for determining cutting stock yields from yellow poplar lumber are presented for each...

Worldwide Esophageal Cancer Collaboration: neoadjuvant pathologic staging data.

PubMed

Rice, T W; Lerut, T E M R; Orringer, M B; Chen, L-Q; Hofstetter, W L; Smithers, B M; Rusch, V W; van Lanschot, J; Chen, K N; Davies, A R; D'Journo, X B; Kesler, K A; Luketich, J D; Ferguson, M K; Räsänen, J V; van Hillegersberg, R; Fang, W; Durand, L; Allum, W H; Cecconello, I; Cerfolio, R J; Pera, M; Griffin, S M; Burger, R; Liu, J-F; Allen, M S; Law, S; Watson, T J; Darling, G E; Scott, W J; Duranceau, A; Denlinger, C E; Schipper, P H; Ishwaran, H; Apperson-Hansen, C; DiPaola, L M; Semple, M E; Blackstone, E H

2016-10-01

To address uncertainty of whether pathologic stage groupings after neoadjuvant therapy (ypTNM) for esophageal cancer share prognostic implications with pathologic groupings after esophagectomy alone (pTNM), we report data-simple descriptions of patient characteristics, cancer categories, and non-risk-adjusted survival-for pathologically staged cancers after neoadjuvant therapy from the Worldwide Esophageal Cancer Collaboration (WECC). Thirty-three institutions from six continents submitted data using variables with standard definitions: demographics, comorbidities, clinical cancer categories, and all-cause mortality from first management decision. Of 7,773 pathologically staged neoadjuvant patients, 2,045 had squamous cell carcinoma, 5,686 adenocarcinoma, 31 adenosquamous carcinoma, and 11 undifferentiated carcinoma. Patients were older (61 years) men (83%) with normal (40%) or overweight (35%) body mass index, 0-1 Eastern Cooperative Oncology Group performance status (96%), and a history of smoking (69%). Cancers were ypT0 (20%), ypT1 (13%), ypT2 (18%), ypT3 (44%), ypN0 (55%), ypM0 (94%), and G2-G3 (72%); most involved the distal esophagus (80%). Non-risk-adjusted survival for yp categories was unequally depressed, more for earlier categories than later, compared with equivalent categories from prior WECC data for esophagectomy-alone patients. Thus, survival of patients with ypT0-2N0M0 cancers was intermediate and similar regardless of ypT; survival for ypN+ cancers was poor. Because prognoses for ypTNM and pTNM categories are dissimilar, prognostication should be based on separate ypTNM categories and groupings. These data will be the basis for the 8th edition cancer staging manuals following risk adjustment for patient, cancer, and treatment characteristics and should direct 9th edition data collection. © 2016 International Society for Diseases of the Esophagus.

Worldwide Esophageal Cancer Collaboration: neoadjuvant pathologic staging data

PubMed Central

Rice, T. W.; Lerut, T. E. M. R.; Orringer, M. B.; Chen, L.-Q.; Hofstetter, W. L.; Smithers, B. M.; Rusch, V. W.; van Lanschot, J.; Chen, K. N.; Davies, A. R.; D’Journo, X. B.; Kesler, K. A.; Luketich, J. D.; Ferguson, M. K.; Rasanen, J. V.; van Hillegersberg, R.; Fang, W.; Durand, L.; Allum, W. H.; Cecconello, I.; Cerfolio, R. J.; Pera, M.; Griffin, S. M.; Burger, R.; Liu, J.-F.; Allen, M. S.; Law, S.; Watson, T. J.; Darling, G. E.; Scott, W. J.; Duranceau, A.; Denlinger, C. E.; Schipper, P. H.; Ishwaran, H.; Apperson-Hansen, C.; DiPaola, L. M.; Semple, M. E.; Blackstone, E. H.

2017-01-01

SUMMARY To address uncertainty of whether pathologic stage groupings after neoadjuvant therapy (ypTNM) for esophageal cancer share prognostic implications with pathologic groupings after esophagectomy alone (pTNM), we report data—simple descriptions of patient characteristics, cancer categories, and non–risk-adjusted survival—for pathologically staged cancers after neoadjuvant therapy from the Worldwide Esophageal Cancer Collaboration (WECC). Thirty-three institutions from six continents submitted data using variables with standard definitions: demographics, comorbidities, clinical cancer categories, and all-cause mortality from first management decision. Of 7,773 pathologically staged neoadjuvant patients, 2,045 had squamous cell carcinoma, 5,686 adenocarcinoma, 31 adenosquamous carcinoma, and 11 undifferentiated carcinoma. Patients were older (61 years) men (83%) with normal (40%) or overweight (35%) body mass index, 0–1 Eastern Cooperative Oncology Group performance status (96%), and a history of smoking (69%). Cancers were ypT0 (20%), ypT1 (13%), ypT2 (18%), ypT3 (44%), ypN0 (55%), ypM0 (94%), and G2-G3 (72%); most involved the distal esophagus (80%). Non–risk-adjusted survival for yp categories was unequally depressed, more for earlier categories than later, compared with equivalent categories from prior WECC data for esophagectomy-alone patients. Thus, survival of patients with ypT0-2N0M0 cancers was intermediate and similar regardless of ypT; survival for ypN+ cancers was poor. Because prognoses for ypTNM and pTNM categories are dissimilar, prognostication should be based on separate ypTNM categories and groupings. These data will be the basis for the 8th edition cancer staging manuals following risk adjustment for patient, cancer, and treatment characteristics and should direct 9th edition data collection. PMID:27731548

Climate Variability and Sugarcane Yield in Louisiana.

NASA Astrophysics Data System (ADS)

Greenland, David

2005-11-01

This paper seeks to understand the role that climate variability has on annual yield of sugarcane in Louisiana. Unique features of sugarcane growth in Louisiana and nonclimatic, yield-influencing factors make this goal an interesting and challenging one. Several methods of seeking and establishing the relations between yield and climate variables are employed. First, yield climate relations were investigated at a single research station where crop variety and growing conditions could be held constant and yield relations could be established between a predominant older crop variety and a newer one. Interviews with crop experts and a literature survey were used to identify potential climatic factors that control yield. A statistical analysis was performed using statewide yield data from the American Sugar Cane League from 1963 to 2002 and a climate database. Yield values for later years were adjusted downward to form an adjusted yield dataset. The climate database was principally constructed from daily and monthly values of maximum and minimum temperature and daily and monthly total precipitation for six cooperative weather-reporting stations representative of the area of sugarcane production. The influence of 74 different, though not independent, climate-related variables on sugarcane yield was investigated. The fact that a climate signal exists is demonstrated by comparing mean values of the climate variables corresponding to the upper and lower third of adjusted yield values. Most of these mean-value differences show an intuitively plausible difference between the high- and low-yield years. The difference between means of the climate variables for years corresponding to the upper and lower third of annual yield values for 13 of the variables is statistically significant at or above the 90% level. A correlation matrix was used to identify the variables that had the largest influence on annual yield. Four variables [called here critical climatic variables (CCV

Effect of warming temperatures on US wheat yields.

PubMed

Tack, Jesse; Barkley, Andrew; Nalley, Lawton Lanier

2015-06-02

Climate change is expected to increase future temperatures, potentially resulting in reduced crop production in many key production regions. Research quantifying the complex relationship between weather variables and wheat yields is rapidly growing, and recent advances have used a variety of model specifications that differ in how temperature data are included in the statistical yield equation. A unique data set that combines Kansas wheat variety field trial outcomes for 1985-2013 with location-specific weather data is used to analyze the effect of weather on wheat yield using regression analysis. Our results indicate that the effect of temperature exposure varies across the September-May growing season. The largest drivers of yield loss are freezing temperatures in the Fall and extreme heat events in the Spring. We also find that the overall effect of warming on yields is negative, even after accounting for the benefits of reduced exposure to freezing temperatures. Our analysis indicates that there exists a tradeoff between average (mean) yield and ability to resist extreme heat across varieties. More-recently released varieties are less able to resist heat than older lines. Our results also indicate that warming effects would be partially offset by increased rainfall in the Spring. Finally, we find that the method used to construct measures of temperature exposure matters for both the predictive performance of the regression model and the forecasted warming impacts on yields.

Spatial variability of climate change impacts on yield of rice and wheat in the Indian Ganga Basin.

PubMed

Mishra, Ashok; Singh, R; Raghuwanshi, N S; Chatterjee, C; Froebrich, Jochen

2013-12-01

Indian Ganga Basin (IGB), one of the most densely populated areas in the world, is facing a significant threat to food grain production, besides increased yield gap between actual and potential production, due to climate change. We have analyzed the spatial variability of climate change impacts on rice and wheat yields at three different locations representing the upper, middle and lower IGB. The DSSAT model is used to simulate the effects of climate variability and climate change on rice and wheat yields by analyzing: (i) spatial crop yield response to current climate, and (ii) impact of a changing climate as projected by two regional climate models, REMO and HadRM3, based on SRES A1B emission scenarios for the period 2011-2040. Results for current climate demonstrate a significant gap between actual and potential yield for upper, middle and lower IGB stations. The analysis based on RCM projections shows that during 2011-2040, the largest reduction in rice and wheat yields will occur in the upper IGB (reduction of potential rice and wheat yield respectively by 43.2% and 20.9% by REMO, and 24.8% and 17.2% by HadRM3). In the lower IGB, however, contrasting results are obtained, with HadRM3 based projections showing an increase in the potential rice and wheat yields, whereas, REMO based projections show decreased potential yields. We discuss the influence of agro-climatic factors; variation in temperature, length of maturity period and leaf area index which are responsible for modeled spatial variability in crop yield response within the IGB. Copyright © 2013 Elsevier B.V. All rights reserved.

Methane yield in source-sorted organic fraction of municipal solid waste.

PubMed

Davidsson, Asa; Gruvberger, Christopher; Christensen, Thomas H; Hansen, Trine Lund; Jansen, Jes la Cour

2007-01-01

Treating the source-separated organic fraction of municipal solid waste (SS-OFMSW) by anaerobic digestion is considered by many municipalities in Europe as an environmentally friendly means of treating organic waste and simultaneously producing methane gas. Methane yield can be used as a parameter for evaluation of the many different systems that exist for sorting and pre-treating waste. Methane yield from the thermophilic pilot scale digestion of 17 types of domestically SS-OFMSW originating from seven full-scale sorting systems was found. The samples were collected during 1 year using worked-out procedures tested statistically to ensure representative samples. Each waste type was identified by its origin and by pre-sorting, collection and pre-treatment methods. In addition to the pilot scale digestion, all samples were examined by chemical analyses and methane potential measurements. A VS-degradation rate of around 80% and a methane yield of 300-400Nm(3) CH(4)/ton VS(in) were achieved with a retention time of 15 days, corresponding to approximately 70% of the methane potential. The different waste samples gave minor variation in chemical composition and thus also in methane yield and methane potential. This indicates that sorting and collection systems in the present study do not significantly affect the amount of methane produced per VS treated.

Production yield of rare-earth ions implanted into an optical crystal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kornher, Thomas, E-mail: t.kornher@physik.uni-stuttgart.de; Xia, Kangwei; Kolesov, Roman

2016-02-01

Rare-earth (RE) ions doped into desired locations of optical crystals might enable a range of novel integrated photonic devices for quantum applications. With this aim, we have investigated the production yield of cerium and praseodymium by means of ion implantation. As a measure, the collected fluorescence intensity from both implanted samples and single centers was used. With a tailored annealing procedure for cerium, a yield up to 53% was estimated. Praseodymium yield amounts up to 91%. Such high implantation yield indicates a feasibility of creation of nanopatterned rare-earth doping and suggests strong potential of RE species for on-chip photonic devices.

Satellite-based studies of maize yield spatial variations and their causes in China

NASA Astrophysics Data System (ADS)

Zhao, Y.

2013-12-01

Maize production in China has been expanding significantly in the past two decades, but yield has become relatively stagnant in the past few years, and needs to be improved to meet increasing demand. Multiple studies found that the gap between potential and actual yield of maize is as large as 40% to 60% of yield potential. Although a few major causes of yield gap have been qualitatively identified with surveys, there has not been spatial analysis aimed at quantifying relative importance of specific biophysical and socio-economic causes, information which would be useful for targeting interventions. This study analyzes the causes of yield variation at field and village level in Quzhou county of North China Plain (NCP). We combine remote sensing and crop modeling to estimate yields in 2009-2012, and identify fields that are consistently high or low yielding. To establish the relationship between yield and potential factors, we gather data on those factors through a household survey. We select targeted survey fields such that not only both extremes of yield distribution but also all soil texture categories in the county is covered. Our survey assesses management and biophysical factors as well as social factors such as farmers' access to agronomic knowledge, which is approximated by distance to the closest demonstration plot or 'Science and technology backyard'. Our survey covers 10 townships, 53 villages and 180 fields. Three to ten farmers are surveyed depending on the amount of variation present among sub pixels of each field. According to survey results, we extract the amount of variation within as well as between villages and or soil type. The higher within village or within field variation, the higher importance of management factors. Factors such as soil type and access to knowledge are more represented by between village variation. Through regression and analysis of variance, we gain more quantitative and thorough understanding of causes to yield variation at

Legume-Cereal Intercropping Improves Forage Yield, Quality and Degradability.

PubMed

Zhang, Jie; Yin, Binjie; Xie, Yuhuai; Li, Jing; Yang, Zaibin; Zhang, Guiguo

2015-01-01

Intercropping legume with cereal is an extensively applied planting pattern in crop cultivation. However, forage potential and the degradability of harvested mixtures from intercropping system remain unclear. To investigate the feasibility of applying an intercropping system as a forage supply source to ruminants, two consecutive experiments (experiments 1 and 2) involving a field cultivation trial and a subsequent in vivo degradable experiment were conducted to determine the forage production performance and the ruminally degradable characteristics of a harvested mixture from an alfalfa/corn-rye intercropping system. In experiment 1, the intercropping system was established by alternating alfalfa and corn or rye with a row ratio of 5:2. Dry matter (DM) and nutrient yields were determined. In experiment 2, forages harvested from the different treatments were used as feedstuff to identify nutrient degradation kinetics and distribution of components between the rapidly degradable (a), potentially degradable (b) and the degradation rate constant (c) of 'b' fraction by in sacco method in Small-Tail Han wether Sheep. The intercropping system of alfalfa and corn-rye provided higher forage production performance with net increases of 9.52% and 34.81% in DM yield, 42.13% and 16.74% in crude protein (CP) yield, 25.94% and 69.99% in degradable DM yield, and 16.96% and 5.50% in degradable CP yield than rotation and alfalfa sole cropping systems, respectively. In addition, the harvest mixture from intercropping system also had greater 'a' fraction, 'b' fraction, 'c' values, and effective degradability (E value) of DM and CP than corn or rye hay harvested from rotation system. After 48-h exposure to rumen microbes, intercropping harvest materials were degraded to a higher extent than separately degraded crop stems from the sole system as indicated by visual microscopic examination with more tissues disappeared. Thus, the intercropping of alfalfa and corn-rye exhibited a greater

The potential of biochar in improving drainage, aeration and maize yields in heavy clay soils

PubMed Central

Mulder, Jan; Hale, Sarah Elizabeth; Nurida, Neneng Laela; Cornelissen, Gerard

2018-01-01

Heavy clay soils are globally widespread but their poor drainage and poor aeration limit their use for agriculture. This study was designed to test the effect of the amendment of biochar (BC) from woody shrubs on drainage/saturated hydraulic conductivity (Ksat), soil aeration/air capacity, available water capacity and biomass and grain yields of maize. In a field experiment, BC from Gliricidia sepium was applied in planting basins or rip lines at 2.5% and 5% w/w in addition to a control without BC. The maize biomass and grain yields were higher in BC treated plots compared to control (p<0.05) during the 2012 and 2013 seasons. There was no significant difference in the yields between 2.5% and 5% BC treatments (e.g. grain yield were 6.6 and 8.1 t ha-1 in 2012 and 9.3 and 10.3 t ha-1 in 2013 compared to control with 4.2 and 6.7 t ha-1 in 2012 and 2013, respectively). Soil from the same field site was also mixed with a similar woody shrub BC from Eupatorium adenophorum in the laboratory at rates of 2.5%, 5% and 10% BC w/w and a control without BC. The mixtures were then incubated and subjected to two wet-dry cycles for two weeks. Core samples were taken from the incubated soil and tested for bulk density, Ksat and pF measurements. Total porosity and moisture at field capacity and wilting point were 72.3%, 43.7% and 23.7%, respectively, and not affected by BC amendment (p>0.05). In contrast, bulk density decreased linearly by 0.011±0.002 g cm-3 per percent BC added (p<0.001). Ksat and air capacity of the soil were 288 cm day-1 and 30.9%, respectively falling within the generally accepted optimal range. Both Ksat and air capacity followed a significant quadratic relation (p<0.05) upon BC addition, decreasing at low BC doses, reaching a minimum at 3–5% BC and increasing at higher doses. Results allowed a partial attribution of the yield increases to changes in soil physical properties such as changes in bulk density and not clearly to Ksat and air capacity. PMID

The potential of biochar in improving drainage, aeration and maize yields in heavy clay soils.

PubMed

Obia, Alfred; Mulder, Jan; Hale, Sarah Elizabeth; Nurida, Neneng Laela; Cornelissen, Gerard

2018-01-01

Heavy clay soils are globally widespread but their poor drainage and poor aeration limit their use for agriculture. This study was designed to test the effect of the amendment of biochar (BC) from woody shrubs on drainage/saturated hydraulic conductivity (Ksat), soil aeration/air capacity, available water capacity and biomass and grain yields of maize. In a field experiment, BC from Gliricidia sepium was applied in planting basins or rip lines at 2.5% and 5% w/w in addition to a control without BC. The maize biomass and grain yields were higher in BC treated plots compared to control (p<0.05) during the 2012 and 2013 seasons. There was no significant difference in the yields between 2.5% and 5% BC treatments (e.g. grain yield were 6.6 and 8.1 t ha-1 in 2012 and 9.3 and 10.3 t ha-1 in 2013 compared to control with 4.2 and 6.7 t ha-1 in 2012 and 2013, respectively). Soil from the same field site was also mixed with a similar woody shrub BC from Eupatorium adenophorum in the laboratory at rates of 2.5%, 5% and 10% BC w/w and a control without BC. The mixtures were then incubated and subjected to two wet-dry cycles for two weeks. Core samples were taken from the incubated soil and tested for bulk density, Ksat and pF measurements. Total porosity and moisture at field capacity and wilting point were 72.3%, 43.7% and 23.7%, respectively, and not affected by BC amendment (p>0.05). In contrast, bulk density decreased linearly by 0.011±0.002 g cm-3 per percent BC added (p<0.001). Ksat and air capacity of the soil were 288 cm day-1 and 30.9%, respectively falling within the generally accepted optimal range. Both Ksat and air capacity followed a significant quadratic relation (p<0.05) upon BC addition, decreasing at low BC doses, reaching a minimum at 3-5% BC and increasing at higher doses. Results allowed a partial attribution of the yield increases to changes in soil physical properties such as changes in bulk density and not clearly to Ksat and air capacity.

Food security in the 21st century: Global yield projections and agricultural expansion

NASA Astrophysics Data System (ADS)

Davis, K. F.; Rulli, M.; D'Odorico, P.

2013-12-01

Global demands on agricultural lands are ever increasing as a result of population growth, changes in diet and increasing biofuel use. By mid-century, the demands for food and fiber are expected to roughly double with the population reaching 9.5 billion. However, earth's finite resource base places a ceiling on the amount of agricultural production that is possible. Several strategies have been widely discussed to meet these rapid increases and to extend the ceiling yet higher, including reducing waste, modifying diets, improving yield and productivity and expanding agriculture and aquaculture. One of the most promising of these is closing the yield gap of currently under-performing agricultural land that has the potential to be much more productive. With high inputs (e.g. irrigation, fertilizers), this strategy has real potential to increase food security, particularly in the developing world where population is expected to sharply increase and where a high potential for yield gap closure exists. Thus it is important to consider whether improvements in global yield can adequately meet global dietary demand during the 21st century. Constructing yield projections to the end of the century, we examine whether global crop production for 154 countries and 16 major food crops under selected agricultural and dietary scenarios can keep pace with estimates of population growth to 2100. By calculating the global production of calories, we are then able to examine how many people can be supported under future scenarios and how closing yield gaps can increase this potential. Our findings agree with previous studies that closing the yield gap alone cannot provide sufficient production by mid-century and that a heavy global dependence on trade will persist throughout the century. Using high-resolution global land suitability maps under a suite of climate models, we find that scenarios incorporating a combination of yield gap closure and agricultural expansion provide the most

Attribution of maize yield increase in China to climate change and technological advancement between 1980 and 2010

NASA Astrophysics Data System (ADS)

Guo, Jianping; Zhao, Junfang; Wu, Dingrong; Mu, Jia; Xu, Yanhong

2014-12-01

Crop yields are affected by climate change and technological advancement. Objectively and quantitatively evaluating the attribution of crop yield change to climate change and technological advancement will ensure sustainable development of agriculture under climate change. In this study, daily climate variables obtained from 553 meteorological stations in China for the period 1961-2010, detailed observations of maize from 653 agricultural meteorological stations for the period 1981-2010, and results using an Agro-Ecological Zones (AEZ) model, are used to explore the attribution of maize (Zea mays L.) yield change to climate change and technological advancement. In the AEZ model, the climatic potential productivity is examined through three step-by-step levels: photosynthetic potential productivity, photosynthetic thermal potential productivity, and climatic potential productivity. The relative impacts of different climate variables on climatic potential productivity of maize from 1961 to 2010 in China are then evaluated. Combined with the observations of maize, the contributions of climate change and technological advancement to maize yield from 1981 to 2010 in China are separated. The results show that, from 1961 to 2010, climate change had a significant adverse impact on the climatic potential productivity of maize in China. Decreased radiation and increased temperature were the main factors leading to the decrease of climatic potential productivity. However, changes in precipitation had only a small effect. The maize yields of the 14 main planting provinces in China increased obviously over the past 30 years, which was opposite to the decreasing trends of climatic potential productivity. This suggests that technological advancement has offset the negative effects of climate change on maize yield. Technological advancement contributed to maize yield increases by 99.6%-141.6%, while climate change contribution was from -41.4% to 0.4%. In particular, the actual

Rice Research to Break Yield Barriers

NASA Astrophysics Data System (ADS)

Verma, Vivek; Ramamoorthy, Rengasamy; Kohli, Ajay; Kumar, Prakash P.

2015-10-01

The world’s population continues to expand and it is expected to cross 9 billion by 2050. This would significantly amplify the demand for food, which will pose serious threats to global food security. Additional challenges are being imposed due to a gradual decrease in the total arable land and global environmental changes. Hence, it is of utmost importance to review and revise the existing food production strategies by incorporating novel biotechnological approaches that can help to break the crop yield barriers in the near future. In this review, we highlight some of the concerns hampering crop yield enhancements. The review also focuses on modern breeding techniques based on genomics as well as proven biotechnological approaches that enable identification and utilization of candidate genes. Another aspect of discussion is the important area of research, namely hormonal regulation of plant development, which is likely to yield valuable regulatory genes for such crop improvement efforts in the future. These strategies can serve as potential tools for developing elite crop varieties for feeding the growing billions.

Hot spots of wheat yield decline with rising temperatures.

PubMed

Asseng, Senthold; Cammarano, Davide; Basso, Bruno; Chung, Uran; Alderman, Phillip D; Sonder, Kai; Reynolds, Matthew; Lobell, David B

2017-06-01

Many of the irrigated spring wheat regions in the world are also regions with high poverty. The impacts of temperature increase on wheat yield in regions of high poverty are uncertain. A grain yield-temperature response function combined with a quantification of model uncertainty was constructed using a multimodel ensemble from two key irrigated spring wheat areas (India and Sudan) and applied to all irrigated spring wheat regions in the world. Southern Indian and southern Pakistani wheat-growing regions with large yield reductions from increasing temperatures coincided with high poverty headcounts, indicating these areas as future food security 'hot spots'. The multimodel simulations produced a linear absolute decline of yields with increasing temperature, with uncertainty varying with reference temperature at a location. As a consequence of the linear absolute yield decline, the relative yield reductions are larger in low-yielding environments (e.g., high reference temperature areas in southern India, southern Pakistan and all Sudan wheat-growing regions) and farmers in these regions will be hit hardest by increasing temperatures. However, as absolute yield declines are about the same in low- and high-yielding regions, the contributed deficit to national production caused by increasing temperatures is higher in high-yielding environments (e.g., northern India) because these environments contribute more to national wheat production. Although Sudan could potentially grow more wheat if irrigation is available, grain yields would be low due to high reference temperatures, with future increases in temperature further limiting production. © 2016 John Wiley & Sons Ltd.

Measurement of fission yields and isomeric yield ratios at IGISOL

NASA Astrophysics Data System (ADS)

Pomp, Stephan; Mattera, Andrea; Rakopoulos, Vasileios; Al-Adili, Ali; Lantz, Mattias; Solders, Andreas; Jansson, Kaj; Prokofiev, Alexander V.; Eronen, Tommi; Gorelov, Dimitri; Jokinen, Ari; Kankainen, Anu; Moore, Iain D.; Penttilä, Heikki; Rinta-Antila, Sami

2018-03-01

Data on fission yields and isomeric yield ratios (IYR) are tools to study the fission process, in particular the generation of angular momentum. We use the IGISOL facility with the Penning trap JYFLTRAP in Jyväskylä, Finland, for such measurements on 232Th and natU targets. Previously published fission yield data from IGISOL concern the 232Th(p,f) and 238U(p,f) reactions at 25 and 50 MeV. Recently, a neutron source, using the Be(p,n) reaction, has been developed, installed and tested. We summarize the results for (p,f) focusing on the first measurement of IYR by direct ion counting. We also present first results for IYR and relative yields for Sn and Sb isotopes in the 128-133 mass range from natU(n,f) based on γ-spectrometry. We find a staggering behaviour in the cumulative yields for Sn and a shift in the independent fission yields for Sb as compared to current evaluations. Plans for the future experimental program on fission yields and IYR measurements are discussed.

Estimates of Sputter Yields of Solar-Wind Heavy Ions of Lunar Regolith Materials

NASA Technical Reports Server (NTRS)

Barghouty, Abdulmasser F.; Adams, James H., Jr.

2008-01-01

At energies of approximately 1 keV/amu, solar-wind protons and heavy ions interact with the lunar surface materials via a number of microscopic interactions that include sputtering. Solar-wind induced sputtering is a main mechanism by which the composition of the topmost layers of the lunar surface can change, dynamically and preferentially. This work concentrates on sputtering induced by solar-wind heavy ions. Sputtering associated with slow (speeds the electrons speed in its first Bohr orbit) and highly charged ions are known to include both kinetic and potential sputtering. Potential sputtering enjoys some unique characteristics that makes it of special interest to lunar science and exploration. Unlike the yield from kinetic sputtering where simulation and approximation schemes exist, the yield from potential sputtering is not as easy to estimate. This work will present a preliminary numerical scheme designed to estimate potential sputtering yields from reactions relevant to this aspect of solar-wind lunar-surface coupling.

High-yield maize with large net energy yield and small global warming intensity

PubMed Central

Grassini, Patricio; Cassman, Kenneth G.

2012-01-01

Addressing concerns about future food supply and climate change requires management practices that maximize productivity per unit of arable land while reducing negative environmental impact. On-farm data were evaluated to assess energy balance and greenhouse gas (GHG) emissions of irrigated maize in Nebraska that received large nitrogen (N) fertilizer (183 kg of N⋅ha−1) and irrigation water inputs (272 mm or 2,720 m3 ha−1). Although energy inputs (30 GJ⋅ha−1) were larger than those reported for US maize systems in previous studies, irrigated maize in central Nebraska achieved higher grain and net energy yields (13.2 Mg⋅ha−1 and 159 GJ⋅ha−1, respectively) and lower GHG-emission intensity (231 kg of CO2e⋅Mg−1 of grain). Greater input-use efficiencies, especially for N fertilizer, were responsible for better performance of these irrigated systems, compared with much lower-yielding, mostly rainfed maize systems in previous studies. Large variation in energy inputs and GHG emissions across irrigated fields in the present study resulted from differences in applied irrigation water amount and imbalances between applied N inputs and crop N demand, indicating potential to further improve environmental performance through better management of these inputs. Observed variation in N-use efficiency, at any level of applied N inputs, suggests that an N-balance approach may be more appropriate for estimating soil N2O emissions than the Intergovernmental Panel on Climate Change approach based on a fixed proportion of applied N. Negative correlation between GHG-emission intensity and net energy yield supports the proposition that achieving high yields, large positive energy balance, and low GHG emissions in intensive cropping systems are not conflicting goals. PMID:22232684

Slope Controls Grain Yield and Climatic Yield in Mountainous Yunnan province, China

NASA Astrophysics Data System (ADS)

Duan, X.; Rong, L.; Gu, Z.; Feng, D.

2017-12-01

Mountainous regions are increasingly vulnerable to food insecurity because of limited arable land, growing population pressure, and climate change. Development of sustainable mountain agriculture will require an increased understanding of the effects of environmental factors on grain and climatic yields. The objective of this study was to explore the relationships between actual grain yield, climatic yield, and environmental factors in a mountainous region in China. We collected data on the average grain yield per unit area in 119 counties in Yunnan province from 1985 to 2012, and chose 17 environmental factors for the same period. Our results showed that actual grain yield ranged from 1.43 to 6.92 t·ha-1, and the climatic yield ranged from -0.15 to -0.01 t·ha-1. Lower climatic yield but higher grain yield was generally found in central areas and at lower slopes and elevations in the western and southwestern counties of Yunnan province. Higher climatic yield but lower grain yield were found in northwestern parts of Yunnan province on steep slopes. Annual precipation and temperature had a weak influence on the climatic yield. Slope explained 44.62 and 26.29% of the variation in grain yield and climatic yield. The effects of topography on grain and climatic yields were greater than climatic factors. Slope was the most important environmental variable for the variability in climatic and grain yields in the mountainous Yunnan province due to the highly heterogeneous topographic conditions. Conversion of slopes to terraces in areas with higher climatic yields is an effective way to maintain grain production in response to climate variability. Additionally, soil amendments and soil and water conservation measures should be considered to maintain soil fertility and aid in sustainable development in central areas, and in counties at lower slopes and elevations in western and southwestern Yunnan province.

Climate change impacts on crop yield in the Euro-Mediterranean region

NASA Astrophysics Data System (ADS)

Toreti, Andrea; Ceglar, Andrej; Dentener, Frank; Niemeyer, Stefan; Dosio, Alessandro; Fumagalli, Davide

2017-04-01

Agriculture is strongly influenced by climate variability, climate extremes and climate changes. Recent studies on past decades have identified and analysed the effects of climate variability and extremes on crop yields in the Euro-Mediterranean region. As these effects could be amplified in a changing climate context, it is essential to analyse available climate projections and investigate the possible impacts on European agriculture in terms of crop yield. In this study, five model runs from the Euro-CORDEX initiative under two scenarios (RCP4.5 and RCP8.5) have been used. Climate model data have been bias corrected and then used to feed a mechanistic crop growth model. The crop model has been run under different settings to better sample the intrinsic uncertainties. Among the main results, it is worth to report a weak but significant and spatially homogeneous increase in potential wheat yield at mid-century (under a CO2 fertilisation effect scenario). While more complex changes seem to characterise potential maize yield, with large areas in the region showing a weak-to-moderate decrease.

Yield performance and stability of CMS-based triticale hybrids.

PubMed

Mühleisen, Jonathan; Piepho, Hans-Peter; Maurer, Hans Peter; Reif, Jochen Christoph

2015-02-01

CMS-based triticale hybrids showed only marginal midparent heterosis for grain yield and lower dynamic yield stability compared to inbred lines. Hybrids of triticale (×Triticosecale Wittmack) are expected to possess outstanding yield performance and increased dynamic yield stability. The objectives of the present study were to (1) examine the optimum choice of the biometrical model to compare yield stability of hybrids versus lines, (2) investigate whether hybrids exhibit a more pronounced grain yield performance and yield stability, and (3) study optimal strategies to predict yield stability of hybrids. Thirteen female and seven male parental lines and their 91 factorial hybrids as well as 30 commercial lines were evaluated for grain yield in up to 20 environments. Hybrids were produced using a cytoplasmic male sterility (CMS)-inducing cytoplasm that originated from Triticumtimopheevii Zhuk. We found that the choice of the biometrical model can cause contrasting results and concluded that a group-by-environment interaction term should be added to the model when estimating stability variance of hybrids and lines. midparent heterosis for grain yield was on average 3 % with a range from -15.0 to 11.5 %. No hybrid outperformed the best inbred line. Hybrids had, on average, lower dynamic yield stability compared to the inbred lines. Grain yield performance of hybrids could be predicted based on midparent values and general combining ability (GCA)-predicted values. In contrast, stability variance of hybrids could be predicted only based on GCA-predicted values. We speculated that negative effects of the used CMS cytoplasm might be the reason for the low performance and yield stability of the hybrids. For this purpose a detailed study on the reasons for the drawback of the currently existing CMS system in triticale is urgently required comprising also the search of potentially alternative hybridization systems.

Benefits of seasonal forecasts of crop yields

NASA Astrophysics Data System (ADS)

Sakurai, G.; Okada, M.; Nishimori, M.; Yokozawa, M.

2017-12-01

Major factors behind recent fluctuations in food prices include increased biofuel production and oil price fluctuations. In addition, several extreme climate events that reduced worldwide food production coincided with upward spikes in food prices. The stabilization of crop yields is one of the most important tasks to stabilize food prices and thereby enhance food security. Recent development of technologies related to crop modeling and seasonal weather forecasting has made it possible to forecast future crop yields for maize and soybean. However, the effective use of these technologies remains limited. Here we present the potential benefits of seasonal crop-yield forecasts on a global scale for choice of planting day. For this purpose, we used a model (PRYSBI-2) that can well replicate past crop yields both for maize and soybean. This model system uses a Bayesian statistical approach to estimate the parameters of a basic process-based model of crop growth. The spatial variability of model parameters was considered by estimating the posterior distribution of the parameters from historical yield data by using the Markov-chain Monte Carlo (MCMC) method with a resolution of 1.125° × 1.125°. The posterior distributions of model parameters were estimated for each spatial grid with 30 000 MCMC steps of 10 chains each. By using this model and the estimated parameter distributions, we were able to estimate not only crop yield but also levels of associated uncertainty. We found that the global average crop yield increased about 30% as the result of the optimal selection of planting day and that the seasonal forecast of crop yield had a large benefit in and near the eastern part of Brazil and India for maize and the northern area of China for soybean. In these countries, the effects of El Niño and Indian Ocean dipole are large. The results highlight the importance of developing a system to forecast global crop yields.

The potential of imposed magnetic fields for enhancing ignition probability and fusion energy yield in indirect-drive inertial confinement fusion

NASA Astrophysics Data System (ADS)

Perkins, L. J.; Ho, D. D.-M.; Logan, B. G.; Zimmerman, G. B.; Rhodes, M. A.; Strozzi, D. J.; Blackfield, D. T.; Hawkins, S. A.

2017-06-01

We examine the potential that imposed magnetic fields of tens of Tesla that increase to greater than 10 kT (100 MGauss) under implosion compression may relax the conditions required for ignition and propagating burn in indirect-drive inertial confinement fusion (ICF) targets. This may allow the attainment of ignition, or at least significant fusion energy yields, in presently performing ICF targets on the National Ignition Facility (NIF) that today are sub-marginal for thermonuclear burn through adverse hydrodynamic conditions at stagnation [Doeppner et al., Phys. Rev. Lett. 115, 055001 (2015)]. Results of detailed two-dimensional radiation-hydrodynamic-burn simulations applied to NIF capsule implosions with low-mode shape perturbations and residual kinetic energy loss indicate that such compressed fields may increase the probability for ignition through range reduction of fusion alpha particles, suppression of electron heat conduction, and potential stabilization of higher-mode Rayleigh-Taylor instabilities. Optimum initial applied fields are found to be around 50 T. Given that the full plasma structure at capsule stagnation may be governed by three-dimensional resistive magneto-hydrodynamics, the formation of closed magnetic field lines might further augment ignition prospects. Experiments are now required to further assess the potential of applied magnetic fields to ICF ignition and burn on NIF.

Reduced product yield in chemical processes by second law effects

NASA Technical Reports Server (NTRS)

England, C.; Funk, J. E.

1980-01-01

An analysis of second law effects in chemical processes, where product yield is explicitly related to the individual irreversibilities within the process to indicate a maximum theoretical yield, is presented. Examples are given that indicate differences between first and second law approaches toward process efficiency and process yield. This analysis also expresses production capacity in terms of the heating value of a product. As a result, it is particularly convenient in analyzing fuel conversion plants and their potential for improvement. Relationships are also given for the effects of irreversibilities on requirements for process heat and for feedstocks.

Potential of Genomic Selection in Mass Selection Breeding of an Allogamous Crop: An Empirical Study to Increase Yield of Common Buckwheat.

PubMed

Yabe, Shiori; Hara, Takashi; Ueno, Mariko; Enoki, Hiroyuki; Kimura, Tatsuro; Nishimura, Satoru; Yasui, Yasuo; Ohsawa, Ryo; Iwata, Hiroyoshi

2018-01-01

To evaluate the potential of genomic selection (GS), a selection experiment with GS and phenotypic selection (PS) was performed in an allogamous crop, common buckwheat ( Fagopyrum esculentum Moench). To indirectly select for seed yield per unit area, which cannot be measured on a single-plant basis, a selection index was constructed from seven agro-morphological traits measurable on a single plant basis. Over 3 years, we performed two GS and one PS cycles per year for improvement in the selection index. In GS, a prediction model was updated every year on the basis of genotypes of 14,598-50,000 markers and phenotypes. Plants grown from seeds derived from a series of generations of GS and PS populations were evaluated for the traits in the selection index and other yield-related traits. GS resulted in a 20.9% increase and PS in a 15.0% increase in the selection index in comparison with the initial population. Although the level of linkage disequilibrium in the breeding population was low, the target trait was improved with GS. Traits with higher weights in the selection index were improved more than those with lower weights, especially when prediction accuracy was high. No trait changed in an unintended direction in either GS or PS. The accuracy of genomic prediction models built in the first cycle decreased in the later cycles because the genetic bottleneck through the selection cycles changed linkage disequilibrium patterns in the breeding population. The present study emphasizes the importance of updating models in GS and demonstrates the potential of GS in mass selection of allogamous crop species, and provided a pilot example of successful application of GS to plant breeding.

Diversity of cacao trees in Waslala, Nicaragua: associations between genotype spectra, product quality and yield potential.

PubMed

Trognitz, Bodo; Cros, Emile; Assemat, Sophie; Davrieux, Fabrice; Forestier-Chiron, Nelly; Ayestas, Eusebio; Kuant, Aldo; Scheldeman, Xavier; Hermann, Michael

2013-01-01

The sensory quality and the contents of quality-determining chemical compounds in unfermented and fermented cocoa from 100 cacao trees (individual genotypes) representing groups of nine genotype spectra (GG), grown at smallholder plantings in the municipality of Waslala, Nicaragua, were evaluated for two successive harvest periods. Cocoa samples were fermented using a technique mimicking recommended on-farm practices. The sensory cocoa quality was assessed by experienced tasters, and seven major chemical taste compounds were quantified by near infrared spectrometry (NIRS). The association of the nine, partially admixed, genotype spectra with the analytical and sensory quality parameters was tested. The individual parameters were analyzed as a function of the factors GG and harvest (including the date of fermentation), individual trees within a single GG were used as replications. In fermented cocoa, significant GG-specific differences were observed for methylxanthines, theobromine-to-caffeine (T/C) ratio, total fat, procyanidin B5 and epicatechin, as well as the sensory attributes global score, astringency, and dry fruit aroma, but differences related to harvest were also apparent. The potential cocoa yield was also highly determined by the individual GG, although there was significant tree-to-tree variation within every single GG. Non-fermented samples showed large harvest-to-harvest variation of their chemical composition, while differences between GG were insignificant. These results suggest that selection by the genetic background, represented here by groups of partially admixed genotype spectra, would be a useful strategy toward enhancing quality and yield of cocoa in Nicaragua. Selection by the GG within the local, genetically segregating populations of seed-propagated cacao, followed by clonal propagation of best-performing individuals of the selected GG could be a viable alternative to traditional propagation of cacao by seed from open pollination. Fast and

Diversity of Cacao Trees in Waslala, Nicaragua: Associations between Genotype Spectra, Product Quality and Yield Potential

PubMed Central

Trognitz, Bodo; Cros, Emile; Assemat, Sophie; Davrieux, Fabrice; Forestier-Chiron, Nelly; Ayestas, Eusebio; Kuant, Aldo; Scheldeman, Xavier; Hermann, Michael

2013-01-01

The sensory quality and the contents of quality-determining chemical compounds in unfermented and fermented cocoa from 100 cacao trees (individual genotypes) representing groups of nine genotype spectra (GG), grown at smallholder plantings in the municipality of Waslala, Nicaragua, were evaluated for two successive harvest periods. Cocoa samples were fermented using a technique mimicking recommended on-farm practices. The sensory cocoa quality was assessed by experienced tasters, and seven major chemical taste compounds were quantified by near infrared spectrometry (NIRS). The association of the nine, partially admixed, genotype spectra with the analytical and sensory quality parameters was tested. The individual parameters were analyzed as a function of the factors GG and harvest (including the date of fermentation), individual trees within a single GG were used as replications. In fermented cocoa, significant GG-specific differences were observed for methylxanthines, theobromine-to-caffeine (T/C) ratio, total fat, procyanidin B5 and epicatechin, as well as the sensory attributes global score, astringency, and dry fruit aroma, but differences related to harvest were also apparent. The potential cocoa yield was also highly determined by the individual GG, although there was significant tree-to-tree variation within every single GG. Non-fermented samples showed large harvest-to-harvest variation of their chemical composition, while differences between GG were insignificant. These results suggest that selection by the genetic background, represented here by groups of partially admixed genotype spectra, would be a useful strategy toward enhancing quality and yield of cocoa in Nicaragua. Selection by the GG within the local, genetically segregating populations of seed-propagated cacao, followed by clonal propagation of best-performing individuals of the selected GG could be a viable alternative to traditional propagation of cacao by seed from open pollination. Fast and

Different universality classes at the yielding transition of amorphous systems

NASA Astrophysics Data System (ADS)

Jagla, E. A.

2017-08-01

We study the yielding transition of a two-dimensional amorphous system under shear by using a mesoscopic elasto-plastic model. The model combines a full (tensorial) description of the elastic interactions in the system and the possibility of structural reaccommodations that are responsible for the plastic behavior. The possible structural reaccommodations are encoded in the form of a "plastic disorder" potential, which is chosen independently at each position of the sample to account for local heterogeneities. We observe that the stress must exceed a critical value σc in order for the system to yield. In addition, when the system yields a flow curve (relating stress σ and strain rate γ ˙) of the form γ ˙˜(σ-σc) β is obtained. Remarkably, we observe the value of β to depend on some details of the plastic disorder potential. For smooth potentials a value of β ≃2.0 is obtained, whereas for potentials obtained as a concatenation of smooth pieces a value β ≃1.5 is observed in the simulations. This indicates a dependence of critical behavior on details of the plastic behavior. In addition, by integrating out nonessential, harmonic degrees of freedom, we derive a simplified scalar version of the model that represents a collection of interacting Prandtl-Tomlinson particles. A mean-field treatment of this interaction reproduces the difference of β exponents for the two classes of plastic disorder potentials and provides values of β that compare favorably with those found in the full simulations.

Mobility of Yield-Stress Fluids on Lubricant-Impregnated Surface

NASA Astrophysics Data System (ADS)

Rapoport, Leonid; Solomon, Brian; Varanasi, Kripa; Varanasi Research Group Team

2017-11-01

Assuring the flow of yield-stress fluids is an essential problem for various industries such as consumer products, health care, and energy. Elimination of wall-induced pinning forces can potentially save power and cleaning costs as well as enable the flow of yield-stress fluids in channels previously considered too narrow. Lubricant-Impregnated Surfaces (LIS) have been demonstrated to change the dynamic behavior of yield-stress fluids and enable them to move as bulk without shearing at all. However, despite the wide applicability of this technology and its general appeal, the fundamental principles governing the performance of yield stress fluids on LIS have not yet been fully explained. In this work, we explore the mobility of yield stress fluids on a wide range of LIS, and explain the connection between macroscale behavior and the microscale properties of the LIS. Specifically, we show a striking difference in mobility between an LIS that contains a lubricant which fully spreads on the rough micro-features of the surface, and an LIS that contains a lubricant which only imbibes these features but does spread over them

Yield Hardening of Electrorheological Fluids in Channel Flow

NASA Astrophysics Data System (ADS)

Helal, Ahmed; Qian, Bian; McKinley, Gareth H.; Hosoi, A. E.

2016-06-01

Electrorheological fluids offer potential for developing rapidly actuated hydraulic devices where shear forces or pressure-driven flow are present. In this study, the Bingham yield stress of electrorheological fluids with different particle volume fractions is investigated experimentally in wall-driven and pressure-driven flow modes using measurements in a parallel-plate rheometer and a microfluidic channel, respectively. A modified Krieger-Dougherty model can be used to describe the effects of the particle volume fraction on the yield stress and is in good agreement with the viscometric data. However, significant yield hardening in pressure-driven channel flow is observed and attributed to an increase and eventual saturation of the particle volume fraction in the channel. A phenomenological physical model linking the densification and consequent microstructure to the ratio of the particle aggregation time scale compared to the convective time scale is presented and used to predict the enhancement in yield stress in channel flow, enabling us to reconcile discrepancies in the literature between wall-driven and pressure-driven flows.

Factors related to well yield in the fractured-bedrock aquifer of New Hampshire

USGS Publications Warehouse

Moore, Richard Bridge; Schwartz, Gregory E.; Clark, Stewart F.; Walsh, Gregory J.; Degnan, James R.

2002-01-01

The New Hampshire Bedrock Aquifer Assessment was designed to provide information that can be used by communities, industry, professional consultants, and other interests to evaluate the ground-water development potential of the fractured-bedrock aquifer in the State. The assessment was done at statewide, regional, and well field scales to identify relations that potentially could increase the success in locating high-yield water supplies in the fractured-bedrock aquifer. statewide, data were collected for well construction and yield information, bedrock lithology, surficial geology, lineaments, topography, and various derivatives of these basic data sets. Regionally, geologic, fracture, and lineament data were collected for the Pinardville and Windham quadrangles in New Hampshire. The regional scale of the study examined the degree to which predictive well-yield relations, developed as part of the statewide reconnaissance investigation, could be improved by use of quadrangle-scale geologic mapping. Beginning in 1984, water-well contractors in the State were required to report detailed information on newly constructed wells to the New Hampshire Department of Environmental Services (NHDES). The reports contain basic data on well construction, including six characteristics used in this study?well yield, well depth, well use, method of construction, date drilled, and depth to bedrock (or length of casing). The NHDES has determined accurate georeferenced locations for more than 20,000 wells reported since 1984. The availability of this large data set provided an opportunity for a statistical analysis of bedrock-well yields. Well yields in the database ranged from zero to greater than 500 gallons per minute (gal/min). Multivariate regression was used as the primary statistical method of analysis because it is the most efficient tool for predicting a single variable with many potentially independent variables. The dependent variable that was explored in this study was the

Yield of reversible colloidal gels during flow start-up: release from kinetic arrest.

PubMed

Johnson, Lilian C; Landrum, Benjamin J; Zia, Roseanna N

2018-06-05

Yield of colloidal gels during start-up of shear flow is characterized by an overshoot in shear stress that accompanies changes in network structure. Prior studies of yield of reversible colloidal gels undergoing strong flow model the overshoot as the point at which network rupture permits fluidization. However, yield under weak flow, which is of interest in many biological and industrial fluids shows no such disintegration. The mechanics of reversible gels are influenced by bond strength and durability, where ongoing rupture and re-formation impart aging that deepens kinetic arrest [Zia et al., J. Rheol., 2014, 58, 1121], suggesting that yield be viewed as release from kinetic arrest. To explore this idea, we study reversible colloidal gels during start-up of shear flow via dynamic simulation, connecting rheological yield to detailed measurements of structure, bond dynamics, and potential energy. We find that pre-yield stress grows temporally with the changing roles of microscopic transport processes: early time behavior is set by Brownian diffusion; later, advective displacements permit relative particle motion that stretches bonds and stores energy. Stress accumulates in stretched, oriented bonds until yield, which is a tipping point to energy release, and is passed with a fully intact network, where the loss of very few bonds enables relaxation of many, easing glassy arrest. This is immediately followed by a reversal to growth in potential energy during bulk plastic deformation and condensation into larger particle domains, supporting the view that yield is an activated release from kinetic arrest. The continued condensation of dense domains and shrinkage of network surfaces, along with a decrease in the potential energy, permit the gel to evolve toward more complete phase separation, supporting our view that yield of weakly sheared gels is a 'non-equilibrium phase transition'. Our findings may be particularly useful for industrial or other coatings, where weak

Prediction of County-Level Corn Yields Using an Energy-Crop Growth Index.

NASA Astrophysics Data System (ADS)

Andresen, Jeffrey A.; Dale, Robert F.; Fletcher, Jerald J.; Preckel, Paul V.

1989-01-01

Weather conditions significantly affect corn yields. while weather remains as the major uncontrolled variable in crop production, an understanding of the influence of weather on yields can aid in early and accurate assessment of the impact of weather and climate on crop yields and allow for timely agricultural extension advisories to help reduce farm management costs and improve marketing, decisions. Based on data for four representative countries in Indiana from 1960 to 1984 (excluding 1970 because of the disastrous southern corn leaf blight), a model was developed to estimate corn (Zea mays L.) yields as a function of several composite soil-crop-weather variables and a technology-trend marker, applied nitrogen fertilizer (N). The model was tested by predicting corn yields for 15 other counties. A daily energy-crop growth (ECG) variable in which different weights were used for the three crop-weather variables which make up the daily ECG-solar radiation intercepted by the canopy, a temperature function, and the ratio of actual to potential evapotranspiration-performed better than when the ECG components were weighted equally. The summation of the weighted daily ECG over a relatively short period (36 days spanning silk) was found to provide the best index for predicting county average corn yield. Numerical estimation results indicate that the ratio of actual to potential evapotranspiration (ET/PET) is much more important than the other two ECG factors in estimating county average corn yield in Indiana.

Rotational Energy.

ERIC Educational Resources Information Center

Lockett, Keith

1988-01-01

Demonstrates several objects rolling down a slope to explain the energy transition among potential energy, translational kinetic energy, and rotational kinetic energy. Contains a problem from Galileo's rolling ball experiment. (YP)

Accelerating yield ramp through design and manufacturing collaboration

NASA Astrophysics Data System (ADS)

Sarma, Robin C.; Dai, Huixiong; Smayling, Michael C.; Duane, Michael P.

2004-12-01

Ramping an integrated circuit from first silicon bring-up to production yield levels is a challenge for all semiconductor products on the path to profitable market entry. Two approaches to accelerating yield ramp are presented. The first is the use of laser mask writers for fast throughput, high yield, and cost effective pattern transfer. The second is the use of electrical test to find a defect and identify the physical region to probe in failure analysis that is most likely to uncover the root cause. This provides feedback to the design team on modifications to make to the design to avoid the yield issue in a future tape-out revision. Additionally, the process parameter responsible for the root cause of the defect is forward annotated through the design, mask and wafer coordinate systems so it can be monitored in-line on subsequent lots of the manufacturing run. This results in an improved recipe for the manufacturing equipment to potentially prevent the recurrence of the defect and raise yield levels on the following material. The test diagnostics approach is enabled by the seamless traceability of a feature across the design, photomask and wafer, made possible by a common data model for design, mask pattern generation and wafer fabrication.

Effects of land use change and seasonality of precipitation on soil nitrogen in a dry tropical forest area in the Western Llanos of Venezuela.

PubMed

González-Pedraza, Ana Francisca; Dezzeo, Nelda

2014-01-01

We evaluated changes of different soil nitrogen forms (total N, available ammonium and nitrate, total N in microbial biomass, and soil N mineralization) after conversion of semideciduous dry tropical forest in 5- and 18-year-old pastures (YP and OP, resp.) in the western Llanos of Venezuela. This evaluation was made at early rainy season, at end rainy season, and during dry season. With few exceptions, no significant differences were detected in the total N in the three study sites. Compared to forest soils, YP showed ammonium losses from 4.2 to 62.9% and nitrate losses from 20.0 to 77.8%, depending on the season of the year. In OP, the ammonium content increased from 50.0 to 69.0% at the end of the rainy season and decreased during the dry season between 25.0 and 55.5%, whereas the nitrate content increased significantly at early rainy season. The net mineralization and the potentially mineralizable N were significantly higher (P < 0.05) in OP than in forest and YP, which would indicate a better quality of the substrate in OP for mineralization. The mineralization rate constant was higher in YP than in forest and OP. This could be associated with a reduced capacity of these soils to preserve the available nitrogen.

Potential for Improved Crop Yield Prediction Through Assimilation of Satellite-Derived Soil Moisture Data

USDA-ARS?s Scientific Manuscript database

Crop yield estimates have a strong impact on dealing with food shortages and on market demand and supply; these estimates are critical for decision-making processes by the U.S. Government, policy makers, stakeholders, etc. Most of the decision making is based on forecasts provided by the U.S. Depart...

Increased SBPase activity improves photosynthesis and grain yield in wheat grown in greenhouse conditions.

PubMed

Driever, Steven M; Simkin, Andrew J; Alotaibi, Saqer; Fisk, Stuart J; Madgwick, Pippa J; Sparks, Caroline A; Jones, Huw D; Lawson, Tracy; Parry, Martin A J; Raines, Christine A

2017-09-26

To meet the growing demand for food, substantial improvements in yields are needed. This is particularly the case for wheat, where global yield has stagnated in recent years. Increasing photosynthesis has been identified as a primary target to achieve yield improvements. To increase leaf photosynthesis in wheat, the level of the Calvin-Benson cycle enzyme sedoheptulose-1,7-biphosphatase (SBPase) has been increased through transformation and expression of a Brachypodium distachyon SBPase gene construct. Transgenic lines with increased SBPase protein levels and activity were grown under greenhouse conditions and showed enhanced leaf photosynthesis and increased total biomass and dry seed yield. This showed the potential of improving yield potential by increasing leaf photosynthesis in a crop species such as wheat. The results are discussed with regard to future strategies for further improvement of photosynthesis in wheat.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'. © 2017 The Authors.

Ranking the Potential Yield of Salinity and Selenium from Subbasins in the Lower Gunnison River Basin Using Seasonal, Multi-parameter Regression Models

NASA Astrophysics Data System (ADS)

Linard, J.; Leib, K.; Colorado Water Science Center

2010-12-01

Elevated levels of salinity and dissolved selenium can detrimentally effect the quality of water where anthropogenic and natural uses are concerned. In areas, such as the lower Gunnison Basin of western Colorado, salinity and selenium are such a concern that control projects are implemented to limit their mobilization. To prioritize the locations in which control projects are implemented, multi-parameter regression models were developed to identify subbasins in the lower Gunnison River Basin that were most likely to have elevated salinity and dissolved selenium levels. The drainage area is about 5,900 mi2 and is underlain by Cretaceous marine shale, which is the most common source of salinity and dissolved selenium. To characterize the complex hydrologic and chemical processes governing constituent mobilization, geospatial variables representing 70 different environmental characteristics were correlated to mean seasonal (irrigation and nonirrigation seasons) salinity and selenium yields estimated at 154 sampling sites. The variables generally represented characteristics of the physical basin, precipitation, soil, geology, land use, and irrigation water delivery systems. Irrigation and nonirrigation seasons were selected due to documented effects of irrigation on constituent mobilization. Following a stepwise approach, combinations of the geospatial variables were used to develop four multi-parameter regression models. These models predicted salinity and selenium yield, within a 95 percent confidence range, at individual points in the Lower Gunnison Basin for irrigation and non-irrigation seasons. The corresponding subbasins were ranked according to their potential to yield salinity and selenium and rankings were used to prioritize areas that would most benefit from control projects.

Notes on Experiments.

ERIC Educational Resources Information Center

Physics Education, 1989

1989-01-01

Introduced are two experiments: radon detection method shows real data using vacuum cleaner, soft toilet paper, and Geiger-Muller tube; critical potentials measurement describes the operation of Teltron tube with VELA. (YP)

Potential of Genomic Selection in Mass Selection Breeding of an Allogamous Crop: An Empirical Study to Increase Yield of Common Buckwheat

PubMed Central

Yabe, Shiori; Hara, Takashi; Ueno, Mariko; Enoki, Hiroyuki; Kimura, Tatsuro; Nishimura, Satoru; Yasui, Yasuo; Ohsawa, Ryo; Iwata, Hiroyoshi

2018-01-01

To evaluate the potential of genomic selection (GS), a selection experiment with GS and phenotypic selection (PS) was performed in an allogamous crop, common buckwheat (Fagopyrum esculentum Moench). To indirectly select for seed yield per unit area, which cannot be measured on a single-plant basis, a selection index was constructed from seven agro-morphological traits measurable on a single plant basis. Over 3 years, we performed two GS and one PS cycles per year for improvement in the selection index. In GS, a prediction model was updated every year on the basis of genotypes of 14,598–50,000 markers and phenotypes. Plants grown from seeds derived from a series of generations of GS and PS populations were evaluated for the traits in the selection index and other yield-related traits. GS resulted in a 20.9% increase and PS in a 15.0% increase in the selection index in comparison with the initial population. Although the level of linkage disequilibrium in the breeding population was low, the target trait was improved with GS. Traits with higher weights in the selection index were improved more than those with lower weights, especially when prediction accuracy was high. No trait changed in an unintended direction in either GS or PS. The accuracy of genomic prediction models built in the first cycle decreased in the later cycles because the genetic bottleneck through the selection cycles changed linkage disequilibrium patterns in the breeding population. The present study emphasizes the importance of updating models in GS and demonstrates the potential of GS in mass selection of allogamous crop species, and provided a pilot example of successful application of GS to plant breeding. PMID:29619035

Is there the potential to adapt soybean (Glycine max Merr.) to future [CO2]? An analysis of the yield response of 18 genotypes in free air CO2 enrichment

USDA-ARS?s Scientific Manuscript database

Rising atmospheric [CO2] is a uniform and global change that increases C3 photosynthesis by suppressing the oxygenation reaction of Rubisco and accelerating carboxylation. This has the potential to provide some offset to the negative effects of global change on crop yields. However, under field cond...

Radiation use efficiency, biomass production, and grain yield in two maize hybrids differing in drought tolerance

USDA-ARS?s Scientific Manuscript database

Drought tolerant (DT) maize (Zea mays L.) hybrids have potential to increase yield under drought conditions. However, little information is known about the physiological determinations of yield in DT hybrids. Our objective was to assess radiation use efficiency (RUE), biomass production, and yield ...

The yield and post-yield behavior of high-density polyethylene

NASA Technical Reports Server (NTRS)

Semeliss, M. A.; Wong, R.; Tuttle, M. E.

1990-01-01

An experimental and analytical evaluation was made of the yield and post-yield behavior of high-density polyethylene, a semi-crystalline thermoplastic. Polyethylene was selected for study because it is very inexpensive and readily available in the form of thin-walled tubes. Thin-walled tubular specimens were subjected to axial loads and internal pressures, such that the specimens were subjected to a known biaxial loading. A constant octahederal shear stress rate was imposed during all tests. The measured yield and post-yield behavior was compared with predictions based on both isotropic and anisotropic models. Of particular interest was whether inelastic behavior was sensitive to the hydrostatic stress level. The major achievements and conclusions reached are discussed.

Regional annual water yield from forest lands and its response to potential deforestation across the southeastern United States

Treesearch

Ge Sun; Steve G. McNulty; J. Lu; Devendra M. Amatya; Y. Liang; R.K. Kolka

2005-01-01

Regional water yield at a meso-scale can be estimated as the difference between precipitation input and evapotranspiration output. Forest water yield from the southeastern US varies greatly both in space and time. Because of the hot climate and high evapotranspiration, less than half of the annual precipitation that falls on forest lands is available for stream flow...

Combined Application of Biofertilizers and Inorganic Nutrients Improves Sweet Potato Yields

PubMed Central

Mukhongo, Ruth W.; Tumuhairwe, John B.; Ebanyat, Peter; AbdelGadir, AbdelAziz H.; Thuita, Moses; Masso, Cargele

2017-01-01

Sweet potato [Ipomoea batatas (L) Lam] yields currently stand at 4.5 t ha−1 on smallholder farms in Uganda, despite the attainable yield (45–48 t ha−1) of NASPOT 11 cultivar comparable to the potential yield (45 t ha−1) in sub-Saharan Africa (SSA). On-farm field experiments were conducted for two seasons in the Mt Elgon High Farmlands and Lake Victoria Crescent agro-ecological zones in Uganda to determine the potential of biofertilizers, specifically arbuscular mycorrhizal fungi (AMF), to increase sweet potato yields (NASPOT 11 cultivar). Two kinds of biofertilizers were compared to different rates of phosphorus (P) fertilizer when applied with or without nitrogen (N) and potassium (K). The sweet potato response to treatments was variable across sites (soil types) and seasons, and significant tuber yield increase (p < 0.05) was promoted by biofertilizer and NPK treatments during the short-rain season in the Ferralsol. Tuber yields ranged from 12.8 to 20.1 t ha−1 in the Rhodic Nitisol (sandy-clay) compared to 7.6 to 14.9 t ha−1 in the Ferralsol (sandy-loam) during the same season. Root colonization was greater in the short-rain season compared to the long-rain season. Biofertilizers combined with N and K realized higher biomass and tuber yield than biofertilizers alone during the short-rain season indicating the need for starter nutrients for hyphal growth and root colonization of AMF. In this study, N0.25PK (34.6 t ha−1) and N0.5PK (32.9 t ha−1) resulted in the highest yield during the long and the short-rain season, respectively, but there was still a yield gap of 11.9 and 13.6 t ha−1 for the cultivar. Therefore, a combination of 90 kg N ha−1 and 100 kg K ha−1 with either 15 or 30 kg P ha−1 can increase sweet potato yield from 4.5 to >30 t ha−1. The results also show that to realize significance of AMF in nutrient depleted soils, starter nutrients should be included. PMID:28348569

Intercropping of two Leucaena spp. with sweet potato: yield, growth rate and biomass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swift, J.F.

1982-01-01

Results of trials with Leucaena leucocephala and Leucaena diversifolia at Wau, Papua New Guinea, showed potential benefits of the agroforestry cropping system. The total biomass yield (sweet potato plus firewood and green manure) was considerably greater than the yield per unit area of sweet potato alone. 3 references.

Biotechnological conversion of spent coffee grounds into polyhydroxyalkanoates and carotenoids.

PubMed

Obruca, Stanislav; Benesova, Pavla; Kucera, Dan; Petrik, Sinisa; Marova, Ivana

2015-12-25

Coffee is one of the world's most popular beverages and has been growing steadily in commercial importance. Nowadays, coffee is the second largest traded commodity in the world, after petroleum. Hence, coffee industry is responsible for the generation of large amounts of waste, especially spent coffee grounds (SCG). Various attempts to valorize this waste stream of coffee industry were made. This article summarizes our research and publications aiming at the conversion of SCG into valuable products - polyhydroxyalkanoates (PHAs) and carotenoids. At first, oil extracted from SCG (approx. 15 wt% oil in SCG) can be efficiently (YP/S=0.82 g/g) converted into PHA employing Cupriavidus necator H16. Further, the solid residues after oil extraction can be hydrolyzed (by the combination of chemical and enzymatic hydrolysis) yielding fermentable sugars, which can be further used as a substrate for the production of PHAs employing Bacillus megaterium (YP/S=0.04 g/g) or Burkholderia cepacia (YP/S=0.24 g/g). Alternatively, SCG hydrolysate can be used as a substrate for biotechnological production of carotenoids by carotenogenic yeast Sporobolomyces roseus. Solid residues after either oil extraction or hydrolysis can be used as fuel in industrial boilers to generate heat and energy. Therefore, entire biomass of SCG can be used for sustainable production of PHAs and/or carotenoids employing bio-refinery approach. Copyright © 2015 Elsevier B.V. All rights reserved.

The Nonlinear Spring and Energy Conservation.

ERIC Educational Resources Information Center

Sherfinski, John

1989-01-01

Describes an air track experiment demonstrating the transfer of mechanical energy from elastic potential to kinetic. Discusses four methods for calculating energy stored in the spring. Included are pictures, typical data, and graphs. (YP)

A new determination of the primordial helium abundance

NASA Astrophysics Data System (ADS)

Peimbert, M.; Peimbert, A.; Luridiana, V.

2017-07-01

We present new Y values for five H II regions, from these values we determine the primordial helium abundance, YP, and obtain that YP = 0.2446 ± 0.0029, (Peimbert, A. et al. 2016, RMxAA, 52, 419). The main difference of our new value with the YP value by Peimbert, M. et al. (2007, ApJ , 666, 633) is due to the use of updated atomic physics parameters. Our YP value is consistent with that by Aver, E. et al. (2015, JCAP, 7, 11), that amounts to YP = 0.2449 ± 0.0040, but in disagreement by more than 3σ with that by Izotov, Y. I. et al. (2014, MNRAS, 443, 778), that amounts to YP = 0.2551 ± 0.0022. YP together with Big Bang Nucleosynthesis, BBN, can be used to put constraints on the number of neutrino families, Nν, and the neutron mean life, τn. The adoption of a neutron mean life of τn = 880.3 ± 1.1 (s) (Olive, K. A et al. 2014, Chinese Physics C, 38, 090001) and our YP value imply that Neff = 2.90 ± 0.22, consistent with 3 neutrino families but not with 4 neutrino families. The adoption of Neff = 3.046 (Mangano, G. and Serpico, P. D. 2011, PhLB, 701, 296) and our YP value imply that τn = 872 ± 14 (s), consistent with both high and low values of τn in the literature. An increase on the quality of the YP determination from H II regions will provide stronger constraints on the Nν and τn values.

Acid soil infertility effects on peanut yields and yield components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blamey, F.P.C.

1983-01-01

The interpretation of soil amelioration experiments with peanuts is made difficult by the unpredictibility of the crop and by the many factors altered when ameliorating acid soils. The present study was conducted to investigate the effects of lime and gypsum applications on peanut kernel yield via the three first order yield components, pods per ha, kernels per pod, and kernel mass. On an acid medium sandy loam soil (typic Plinthustult), liming resulted in a highly significant kernel yield increase of 117% whereas gypsum applications were of no significant benefit. As indicated by path coefficient analysis, an increase in the numbermore » of pods per ha was markedly more important in increasing yield than an increase in either the number of kernels per pod or kernel mass. Furthermore, exch. Al was found to be particularly detrimental to pod number. It was postulated that poor peanut yields resulting from acid soil infertility were mainly due to the depressive effect of exch. Al on pod number. Exch. Ca appeared to play a secondary role by ameliorating the adverse effects of exch. Al.« less

Automatic yield-line analysis of slabs using discontinuity layout optimization

PubMed Central

Gilbert, Matthew; He, Linwei; Smith, Colin C.; Le, Canh V.

2014-01-01

The yield-line method of analysis is a long established and extremely effective means of estimating the maximum load sustainable by a slab or plate. However, although numerous attempts to automate the process of directly identifying the critical pattern of yield-lines have been made over the past few decades, to date none has proved capable of reliably analysing slabs of arbitrary geometry. Here, it is demonstrated that the discontinuity layout optimization (DLO) procedure can successfully be applied to such problems. The procedure involves discretization of the problem using nodes inter-connected by potential yield-line discontinuities, with the critical layout of these then identified using linear programming. The procedure is applied to various benchmark problems, demonstrating that highly accurate solutions can be obtained, and showing that DLO provides a truly systematic means of directly and reliably automatically identifying yield-line patterns. Finally, since the critical yield-line patterns for many problems are found to be quite complex in form, a means of automatically simplifying these is presented. PMID:25104905

Predawn respiration rates during flowering are highly predictive of yield response in Gossypium hirsutum when yield variability is water-induced.

PubMed

Snider, John L; Chastain, Daryl R; Meeks, Calvin D; Collins, Guy D; Sorensen, Ronald B; Byrd, Seth A; Perry, Calvin D

2015-07-01

Respiratory carbon evolution by leaves under abiotic stress is implicated as a major limitation to crop productivity; however, respiration rates of fully expanded leaves are positively associated with plant growth rates. Given the substantial sensitivity of plant growth to drought, it was hypothesized that predawn respiration rates (RPD) would be (1) more sensitive to drought than photosynthetic processes and (2) highly predictive of water-induced yield variability in Gossypium hirsutum. Two studies (at Tifton and Camilla Georgia) addressed these hypotheses. At Tifton, drought was imposed beginning at the onset of flowering (first flower) and continuing for three weeks (peak bloom) followed by a recovery period, and predawn water potential (ΨPD), RPD, net photosynthesis (AN) and maximum quantum yield of photosystem II (Fv/Fm) were measured throughout the study period. At Camilla, plants were exposed to five different irrigation regimes throughout the growing season, and average ΨPD and RPD were determined between first flower and peak bloom for all treatments. For both sites, fiber yield was assessed at crop maturity. The relationships between ΨPD, RPD and yield were assessed via non-linear regression. It was concluded for field-grown G. hirsutum that (1) RPD is exceptionally sensitive to progressive drought (more so than AN or Fv/Fm) and (2) average RPD from first flower to peak bloom is highly predictive of water-induced yield variability. Copyright © 2015 Elsevier GmbH. All rights reserved.

Field-based high throughput phenotyping rapidly identifies genomic regions controlling yield components in rice

PubMed Central

Tanger, Paul; Klassen, Stephen; Mojica, Julius P.; Lovell, John T.; Moyers, Brook T.; Baraoidan, Marietta; Naredo, Maria Elizabeth B.; McNally, Kenneth L.; Poland, Jesse; Bush, Daniel R.; Leung, Hei; Leach, Jan E.; McKay, John K.

2017-01-01

To ensure food security in the face of population growth, decreasing water and land for agriculture, and increasing climate variability, crop yields must increase faster than the current rates. Increased yields will require implementing novel approaches in genetic discovery and breeding. Here we demonstrate the potential of field-based high throughput phenotyping (HTP) on a large recombinant population of rice to identify genetic variation underlying important traits. We find that detecting quantitative trait loci (QTL) with HTP phenotyping is as accurate and effective as traditional labor-intensive measures of flowering time, height, biomass, grain yield, and harvest index. Genetic mapping in this population, derived from a cross of an modern cultivar (IR64) with a landrace (Aswina), identified four alleles with negative effect on grain yield that are fixed in IR64, demonstrating the potential for HTP of large populations as a strategy for the second green revolution. PMID:28220807

Biochar potential in intensive cultivation of Capsicum annuum L. (sweet pepper): crop yield and plant protection.

PubMed

Kumar, Abhay; Elad, Yigal; Tsechansky, Ludmila; Abrol, Vikas; Lew, Beni; Offenbach, Rivka; Graber, Ellen R

2018-01-01

The influence of various biochars on crop yield and disease resistance of Capsicum annuum L. (sweet pepper) under modern, high input, intensive net house cultivation was tested over the course of 2011-2014 in the Arava desert region of Israel. A pot experiment with Lactuca sativa L. (lettuce) grown in the absence of fertilizer employed the 3-year-old field trial soils to determine if biochar treatments contributed to soil intrinsic fertility. Biochar amendments resulted in a significant increase in the number and weight of pepper fruits over 3 years. Concomitant with the increased yield, biochar significantly decreased the severity of powdery mildew (Leveillula taurica) disease and broad mite (Polyphagotarsonemus latus) pest infestation. Biochar additions resulted in increased soil organic matter but did not influence the pH, electrical conductivity or soil or plant mineral nutrients. Intrinsic fertility experiments with lettuce showed that two of the four biochar-treated field soils had significant positive impacts on lettuce fresh weight and total chlorophyll, carotenoid and anthocyanin contents. Biochar-based soil management can enhance the functioning of intensive, commercial, net house production of peppers under the tested conditions, resulting in increased crop yield and plant resistance to disease over several years. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Biomass yielding potential of naturally regenerated Prosopis juliflora tree stands at three varied ecosystems in southern districts of Tamil Nadu, India.

PubMed

Saraswathi, K; Chandrasekaran, S

2016-05-01

Fuel energy demand is of great concern in recent times due to the depletion of fossil fuel resources. Biomass serves as widely available primary renewable energy source. Hence, a study was performed to assess the above-ground biomass yielding capability of fuel wood tree Prosopis juliflora in three varied ecosystems viz., coastal, fallow land and riparian ecosystems in southern districts of Tamil Nadu. The results showed that the biomass production potential and above-ground net primary productivity of P. juliflora depend on the age of the tree stands and the nature of ecosystem. A higher biomass yield was observed for P. juliflora trees with 5 to 10 years old when compared to less than 5 years of their age. Among the three ecosystems, the maximum biomass production was recorded in riparian ecosystem. The stands with less than 5-year-old P. juliflora trees gave 1.40 t/ha, and 5- to 10-year-old tree stands produced 27.69 t/ha in riparian ecosystem. Above-ground net primary productivity of both the age groups was high in fallow land ecosystem. In riparian ecosystem, the wood showed high density and low sulphur content than the other two ecosystems. Hence, P. juliflora biomass can serve as an environmentally and economically feasible fuel as well as their utilization proffers an effective means to control its invasiveness.

Possible changes to arable crop yields by 2050

PubMed Central

Jaggard, Keith W.; Qi, Aiming; Ober, Eric S.

2010-01-01

By 2050, the world population is likely to be 9.1 billion, the CO2 concentration 550 ppm, the ozone concentration 60 ppb and the climate warmer by ca 2°C. In these conditions, what contribution can increased crop yield make to feeding the world? CO2 enrichment is likely to increase yields of most crops by approximately 13 per cent but leave yields of C4 crops unchanged. It will tend to reduce water consumption by all crops, but this effect will be approximately cancelled out by the effect of the increased temperature on evaporation rates. In many places increased temperature will provide opportunities to manipulate agronomy to improve crop performance. Ozone concentration increases will decrease yields by 5 per cent or more. Plant breeders will probably be able to increase yields considerably in the CO2-enriched environment of the future, and most weeds and airborne pests and diseases should remain controllable, so long as policy changes do not remove too many types of crop-protection chemicals. However, soil-borne pathogens are likely to be an increasing problem when warmer weather will increase their multiplication rates; control is likely to need a transgenic approach to breeding for resistance. There is a large gap between achievable yields and those delivered by farmers, even in the most efficient agricultural systems. A gap is inevitable, but there are large differences between farmers, even between those who have used the same resources. If this gap is closed and accompanied by improvements in potential yields then there is a good prospect that crop production will increase by approximately 50 per cent or more by 2050 without extra land. However, the demands for land to produce bio-energy have not been factored into these calculations. PMID:20713388

Possible changes to arable crop yields by 2050.

PubMed

Jaggard, Keith W; Qi, Aiming; Ober, Eric S

2010-09-27

By 2050, the world population is likely to be 9.1 billion, the CO(2) concentration 550 ppm, the ozone concentration 60 ppb and the climate warmer by ca 2 degrees C. In these conditions, what contribution can increased crop yield make to feeding the world? CO(2) enrichment is likely to increase yields of most crops by approximately 13 per cent but leave yields of C4 crops unchanged. It will tend to reduce water consumption by all crops, but this effect will be approximately cancelled out by the effect of the increased temperature on evaporation rates. In many places increased temperature will provide opportunities to manipulate agronomy to improve crop performance. Ozone concentration increases will decrease yields by 5 per cent or more. Plant breeders will probably be able to increase yields considerably in the CO(2)-enriched environment of the future, and most weeds and airborne pests and diseases should remain controllable, so long as policy changes do not remove too many types of crop-protection chemicals. However, soil-borne pathogens are likely to be an increasing problem when warmer weather will increase their multiplication rates; control is likely to need a transgenic approach to breeding for resistance. There is a large gap between achievable yields and those delivered by farmers, even in the most efficient agricultural systems. A gap is inevitable, but there are large differences between farmers, even between those who have used the same resources. If this gap is closed and accompanied by improvements in potential yields then there is a good prospect that crop production will increase by approximately 50 per cent or more by 2050 without extra land. However, the demands for land to produce bio-energy have not been factored into these calculations.

Development of LACIE CCEA-1 weather/wheat yield models. [regression analysis

NASA Technical Reports Server (NTRS)

Strommen, N. D.; Sakamoto, C. M.; Leduc, S. K.; Umberger, D. E. (Principal Investigator)

1979-01-01

The advantages and disadvantages of the casual (phenological, dynamic, physiological), statistical regression, and analog approaches to modeling for grain yield are examined. Given LACIE's primary goal of estimating wheat production for the large areas of eight major wheat-growing regions, the statistical regression approach of correlating historical yield and climate data offered the Center for Climatic and Environmental Assessment the greatest potential return within the constraints of time and data sources. The basic equation for the first generation wheat-yield model is given. Topics discussed include truncation, trend variable, selection of weather variables, episodic events, strata selection, operational data flow, weighting, and model results.

Yield Advances in Peanut

USDA-ARS?s Scientific Manuscript database

Average yields of peanut in the U.S. set an all time record of 4,695 kg ha-1 in 2012. This far exceeded the previous record yield of 3,837 kg ha-1 in 2008. Favorable weather conditions undoubtedly contributed to the record yields in 2012; however, these record yields would not have been achievable...

Managing Southeastern US Forests for Increased Water Yield

NASA Astrophysics Data System (ADS)

Acharya, S.; Kaplan, D. A.; Mclaughlin, D. L.; Cohen, M. J.

2017-12-01

Forested lands influence watershed hydrology by affecting water quantity and quality in surface and groundwater systems, making them potentially effective tools for regional water resource planning. In this study, we quantified water use and water yield by pine forests under varying silvicultural management (e.g., high density plantation, thinning, and prescribed burning). Daily forest water use (evapotranspiration, ET) was estimated using continuously monitored soil-moisture in the root-zone at six sites across Florida (USA), each with six plots ranging in forest leaf-area index (LAI). Plots included stands with different rotational ages (from clear-cut to mature pine plantations) and those restored to more historical conditions. Estimated ET relative to potential ET (PET) was strongly associated with LAI, root-zone soil-moisture status, and site hydroclimate; these factors explained 85% of the variation in the ET:PET ratio. Annual water yield (Yw) calculated from these ET estimates and a simple water balance differed significantly among sites and plots (ranging from -0.12 cm/yr to > 100 cm/yr), demonstrating substantive influence of management regimes. LAI strongly influenced Yw in all sites, and a general linear model with forest attributes (LAI and groundcover), hydroclimate, and site characteristics explained >90% of variation in observed Yw. These results can be used to predict water yield changes under different management and climate scenarios and may be useful in the development of payment for ecosystem services approaches that identify water as an important product of forest best management practices.

Effects of Land Use Change and Seasonality of Precipitation on Soil Nitrogen in a Dry Tropical Forest Area in the Western Llanos of Venezuela

PubMed Central

González-Pedraza, Ana Francisca; Dezzeo, Nelda

2014-01-01

We evaluated changes of different soil nitrogen forms (total N, available ammonium and nitrate, total N in microbial biomass, and soil N mineralization) after conversion of semideciduous dry tropical forest in 5- and 18-year-old pastures (YP and OP, resp.) in the western Llanos of Venezuela. This evaluation was made at early rainy season, at end rainy season, and during dry season. With few exceptions, no significant differences were detected in the total N in the three study sites. Compared to forest soils, YP showed ammonium losses from 4.2 to 62.9% and nitrate losses from 20.0 to 77.8%, depending on the season of the year. In OP, the ammonium content increased from 50.0 to 69.0% at the end of the rainy season and decreased during the dry season between 25.0 and 55.5%, whereas the nitrate content increased significantly at early rainy season. The net mineralization and the potentially mineralizable N were significantly higher (P < 0.05) in OP than in forest and YP, which would indicate a better quality of the substrate in OP for mineralization. The mineralization rate constant was higher in YP than in forest and OP. This could be associated with a reduced capacity of these soils to preserve the available nitrogen. PMID:25610907

Quantitative Trait Loci for Yield and Yield-Related Traits in Spring Barley Populations Derived from Crosses between European and Syrian Cultivars

PubMed Central

Krystkowiak, Karolina; Sawikowska, Aneta; Frohmberg, Wojciech; Górny, Andrzej; Kędziora, Andrzej; Jankowiak, Janusz; Józefczyk, Damian; Karg, Grzegorz; Andrusiak, Joanna; Krajewski, Paweł; Szarejko, Iwona; Surma, Maria; Adamski, Tadeusz; Guzy-Wróbelska, Justyna; Kuczyńska, Anetta

2016-01-01

In response to climatic changes, breeding programmes should be aimed at creating new cultivars with improved resistance to water scarcity. The objective of this study was to examine the yield potential of barley recombinant inbred lines (RILs) derived from three cross-combinations of European and Syrian spring cultivars, and to identify quantitative trait loci (QTLs) for yield-related traits in these populations. RILs were evaluated in field experiments over a period of three years (2011 to 2013) and genotyped with simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers; a genetic map for each population was constructed and then one consensus map was developed. Biological interpretation of identified QTLs was achieved by reference to Ensembl Plants barley gene space. Twelve regions in the genomes of studied RILs were distinguished after QTL analysis. Most of the QTLs were identified on the 2H chromosome, which was the hotspot region in all three populations. Syrian parental cultivars contributed alleles decreasing traits' values at majority of QTLs for grain weight, grain number, spike length and time to heading, and numerous alleles increasing stem length. The phenomic and molecular approaches distinguished the lines with an acceptable grain yield potential combining desirable features or alleles from their parents, that is, early heading from the Syrian breeding line (Cam/B1/CI08887//CI05761) and short plant stature from the European semidwarf cultivar (Maresi). PMID:27227880

Field-based high throughput phenotyping rapidly identifies genomic regions controlling yield components in rice

DOE PAGES

Tanger, Paul; Klassen, Stephen; Mojica, Julius P.; ...

2017-02-21

In order to ensure food security in the face of population growth, decreasing water and land for agriculture, and increasing climate variability, crop yields must increase faster than the current rates. Increased yields will require implementing novel approaches in genetic discovery and breeding. We demonstrate the potential of field-based high throughput phenotyping (HTP) on a large recombinant population of rice to identify genetic variation underlying important traits. We find that detecting quantitative trait loci (QTL) with HTP phenotyping is as accurate and effective as traditional labor- intensive measures of flowering time, height, biomass, grain yield, and harvest index. Furthermore, geneticmore » mapping in this population, derived from a cross of an modern cultivar (IR64) with a landrace (Aswina), identified four alleles with negative effect on grain yield that are fixed in IR64, demonstrating the potential for HTP of large populations as a strategy for the second green revolution.« less

Field-based high throughput phenotyping rapidly identifies genomic regions controlling yield components in rice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanger, Paul; Klassen, Stephen; Mojica, Julius P.

In order to ensure food security in the face of population growth, decreasing water and land for agriculture, and increasing climate variability, crop yields must increase faster than the current rates. Increased yields will require implementing novel approaches in genetic discovery and breeding. We demonstrate the potential of field-based high throughput phenotyping (HTP) on a large recombinant population of rice to identify genetic variation underlying important traits. We find that detecting quantitative trait loci (QTL) with HTP phenotyping is as accurate and effective as traditional labor- intensive measures of flowering time, height, biomass, grain yield, and harvest index. Furthermore, geneticmore » mapping in this population, derived from a cross of an modern cultivar (IR64) with a landrace (Aswina), identified four alleles with negative effect on grain yield that are fixed in IR64, demonstrating the potential for HTP of large populations as a strategy for the second green revolution.« less

Development of High Yield Feedstocks and Biomass Conversion Technology for Renewable Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hashimoto, Andrew G.; Crow, Susan; DeBeryshe, Barbara

2015-04-09

This project had two main goals. The first goal was to evaluate several high yielding tropical perennial grasses as feedstock for biofuel production, and to characterize the feedstock for compatible biofuel production systems. The second goal was to assess the integration of renewable energy systems for Hawaii. The project focused on high-yield grasses (napiergrass, energycane, sweet sorghum, and sugarcane). Field plots were established to evaluate the effects of elevation (30, 300 and 900 meters above sea level) and irrigation (50%, 75% and 100% of sugarcane plantation practice) on energy crop yields and input. The test plots were extensive monitored including:more » hydrologic studies to measure crop water use and losses through seepage and evapotranspiration; changes in soil carbon stock; greenhouse gas flux (CO 2, CH 4, and N 2O) from the soil surface; and root morphology, biomass, and turnover. Results showed significant effects of environment on crop yields. In general, crop yields decrease as the elevation increased, being more pronounced for sweet sorghum and energycane than napiergrass. Also energy crop yields were higher with increased irrigation levels, being most pronounced with energycane and less so with sweet sorghum. Daylight length greatly affected sweet sorghum growth and yields. One of the energy crops (napiergrass) was harvested at different ages (2, 4, 6, and 8 months) to assess the changes in feedstock characteristics with age and potential to generate co-products. Although there was greater potential for co-products from younger feedstock, the increased production was not sufficient to offset the additional cost of harvesting multiple times per year. The feedstocks were also characterized to assess their compatibility with biochemical and thermochemical conversion processes. The project objectives are being continued through additional support from the Office of Naval Research, and the Biomass Research and Development Initiative. Renewable

Growth, yield and compositional characteristics of Jerusalem artichoke as it relates to biomass production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stauffer, M.D.; Chubey, B.B.; Dorrell, D.G.

1980-01-01

Jerusalem artichoke (Helianthus tuberosus L.) has shown excellent potential as a carbohydrate-rich crop. Initial investigations determined inulin and tuber yields; however, when additional studies showed that good quality pulp remained after inulin extraction and high forage yields per hectare were obtainable, the scope of investigation was broadened to assess utilization of the total plant. Plant growth, yield and compositional characteristics of Jerusalem artichoke as they relate to biomass production will be reported.

A regionally-adapted implementation of conservation agriculture delivers rapid improvements to soil properties associated with crop yield stability.

PubMed

Williams, Alwyn; Jordan, Nicholas R; Smith, Richard G; Hunter, Mitchell C; Kammerer, Melanie; Kane, Daniel A; Koide, Roger T; Davis, Adam S

2018-05-31

Climate models predict increasing weather variability, with negative consequences for crop production. Conservation agriculture (CA) may enhance climate resilience by generating certain soil improvements. However, the rate at which these improvements accrue is unclear, and some evidence suggests CA can lower yields relative to conventional systems unless all three CA elements are implemented: reduced tillage, sustained soil cover, and crop rotational diversity. These cost-benefit issues are important considerations for potential adopters of CA. Given that CA can be implemented across a wide variety of regions and cropping systems, more detailed and mechanistic understanding is required on whether and how regionally-adapted CA can improve soil properties while minimizing potential negative crop yield impacts. Across four US states, we assessed short-term impacts of regionally-adapted CA systems on soil properties and explored linkages with maize and soybean yield stability. Structural equation modeling revealed increases in soil organic matter generated by cover cropping increased soil cation exchange capacity, which improved soybean yield stability. Cover cropping also enhanced maize minimum yield potential. Our results demonstrate individual CA elements can deliver rapid improvements in soil properties associated with crop yield stability, suggesting that regionally-adapted CA may play an important role in developing high-yielding, climate-resilient agricultural systems.

Using FACE systems to screen wheat cultivars for yield increases at elevated CO2

USDA-ARS?s Scientific Manuscript database

Because of continuing increases in atmospheric CO2, identifying cultivars of crops with larger yield increases at elevated CO2 may provide an avenue to increase crop yield potential in future climates. Free-air CO2 enrichment (FACE) systems have most often been used with multiple replications of ea...

Biochar and flyash inoculated with plant growth promoting rhizobacteria act as potential biofertilizer for luxuriant growth and yield of tomato plant.

PubMed

Tripti; Kumar, Adarsh; Usmani, Zeba; Kumar, Vipin; Anshumali

2017-04-01

Overuse of agrochemical fertilizers alarmingly causes deterioration in soil health and soil-flora. Persistence of these agrochemicals exerts detrimental effects on environment, potentially inducing toxic effects on human health, thus pronouncing an urgent need for a safer substitute. The present study investigates the potential use of agricultural and industrial wastes as carrier materials, viz. biochar and flyash, respectively, for preparation of bioformulations (or biofertilizers) using two plant growth promoting rhizobacteria, Bacillus sp. strain A30 and Burkholderia sp. strain L2, and its effect on growth of Lycopersicon esculentum Mill. (tomato). The viability of strains was determined based on colony forming units (cfu) count of each bioformulation at an interval of 60 days for a period of 240 days. Seeds were coated with different carrier based bioformulations and pot experiment(s) were carried out to access its effects on plant growth parameters. Biochar based bioformulations showed higher cfu count and maximum viability for strain L2 (10 7  cfu g -1 ) at 240 days of storage. Maximum percentage of seed germination was also observed in biochar inoculated with strain L2. Significant (p < 0.05) increase in plant growth parameters (dry and fresh biomass, length, number of flowers) were ascertained from the pot experiment and amongst all bioformulations, biochar inoculated with strain L2 performed consistently thriving results for tomato yield. Furthermore, post-harvest study of this bioformulation treated soil improved physico-chemical properties and dehydrogenase activity as compared to pre-plantation soil status. Overall, we show that prepared biochar based bioformulation using Burkholderia sp. L2 as inoculum can tremendously enhance the productivity of tomato, soil fertility, and can also act as a sustainable substitute for chemical fertilizers. In addition, mixture of biochar and flyash inoculated with strain L2 also showed noteworthy results for the

Effect of nitrogen levels and nitrogen ratios on lodging resistance and yield potential of winter wheat (Triticum aestivum L.)

PubMed Central

Wang, Hui; Yi, Yuan; Ding, Jinfeng; Zhu, Min; Li, Chunyan; Guo, Wenshan; Feng, Chaonian; Zhu, Xinkai

2017-01-01

Lodging is one of the constraints that limit wheat yields and quality due to the unexpected bending or breaking stems on wheat (Triticum aestivum L.) production worldwide. In addition to choosing lodging resistance varieties, husbandry practices also have a significant effect on lodging. Nitrogen management is one of the most common and efficient methods. A field experiment with Yangmai 20 as research material (a widely-used variety) was conducted to study the effects of different nitrogen levels and ratios on culm morphological, anatomical characters and chemical components and to explore the nitrogen application techniques for lodging tolerance and high yield. Results showed that some index of basal internodes, such as stem wall thickness, filling degree, lignin content, cellulose content, water-soluble carbohydrate (WSC) and WSC/N ratio, were positively and significantly correlated with culm lodging-resistant index (CLRI). As the increase of nitrogen level and basal nitrogen ratio, the basal internodes became slender and fragile with the thick stem wall, while filling degree, chemical components and the strength of the stem decreased gradually, which significantly increased the lodging risk. The response of grain yield to nitrogen doses was quadratic and grain yield reached the highest at the nitrogen ratio of 50%:10%:20%:20% (the ratio of nitrogen amount applied before sowing, at tillering stage, jointing stage and booting stage respectively, abbreviated as 5:1:2:2). These results suggested that for Yangmai 20, the planting density of 180×104ha-1, nitrogen level of 225 kg ha-1, and the ratio of 5: 1: 2: 2 effectively increased lodging resistance and grain yield. This combination of planting density and nitrogen level and ratio could effectively relieve the contradiction between high-yielding and anti-lodging. PMID:29117250

Effect of nitrogen levels and nitrogen ratios on lodging resistance and yield potential of winter wheat (Triticum aestivum L.).

PubMed

Zhang, Mingwei; Wang, Hui; Yi, Yuan; Ding, Jinfeng; Zhu, Min; Li, Chunyan; Guo, Wenshan; Feng, Chaonian; Zhu, Xinkai

2017-01-01

Lodging is one of the constraints that limit wheat yields and quality due to the unexpected bending or breaking stems on wheat (Triticum aestivum L.) production worldwide. In addition to choosing lodging resistance varieties, husbandry practices also have a significant effect on lodging. Nitrogen management is one of the most common and efficient methods. A field experiment with Yangmai 20 as research material (a widely-used variety) was conducted to study the effects of different nitrogen levels and ratios on culm morphological, anatomical characters and chemical components and to explore the nitrogen application techniques for lodging tolerance and high yield. Results showed that some index of basal internodes, such as stem wall thickness, filling degree, lignin content, cellulose content, water-soluble carbohydrate (WSC) and WSC/N ratio, were positively and significantly correlated with culm lodging-resistant index (CLRI). As the increase of nitrogen level and basal nitrogen ratio, the basal internodes became slender and fragile with the thick stem wall, while filling degree, chemical components and the strength of the stem decreased gradually, which significantly increased the lodging risk. The response of grain yield to nitrogen doses was quadratic and grain yield reached the highest at the nitrogen ratio of 50%:10%:20%:20% (the ratio of nitrogen amount applied before sowing, at tillering stage, jointing stage and booting stage respectively, abbreviated as 5:1:2:2). These results suggested that for Yangmai 20, the planting density of 180×104ha-1, nitrogen level of 225 kg ha-1, and the ratio of 5: 1: 2: 2 effectively increased lodging resistance and grain yield. This combination of planting density and nitrogen level and ratio could effectively relieve the contradiction between high-yielding and anti-lodging.

Analysis of climate signals in the crop yield record of sub-Saharan Africa.

PubMed

Hoffman, Alexis L; Kemanian, Armen R; Forest, Chris E

2018-01-01

Food security and agriculture productivity assessments in sub-Saharan Africa (SSA) require a better understanding of how climate and other drivers influence regional crop yields. In this paper, our objective was to identify the climate signal in the realized yields of maize, sorghum, and groundnut in SSA. We explored the relation between crop yields and scale-compatible climate data for the 1962-2014 period using Random Forest, a diagnostic machine learning technique. We found that improved agricultural technology and country fixed effects are three times more important than climate variables for explaining changes in crop yields in SSA. We also found that increasing temperatures reduced yields for all three crops in the temperature range observed in SSA, while precipitation increased yields up to a level roughly matching crop evapotranspiration. Crop yields exhibited both linear and nonlinear responses to temperature and precipitation, respectively. For maize, technology steadily increased yields by about 1% (13 kg/ha) per year while increasing temperatures decreased yields by 0.8% (10 kg/ha) per °C. This study demonstrates that although we should expect increases in future crop yields due to improving technology, the potential yields could be progressively reduced due to warmer and drier climates. © 2017 John Wiley & Sons Ltd.

Soviet test yields

NASA Astrophysics Data System (ADS)

Vergino, Eileen S.

Soviet seismologists have published descriptions of 96 nuclear explosions conducted from 1961 through 1972 at the Semipalatinsk test site, in Kazakhstan, central Asia [Bocharov et al., 1989]. With the exception of releasing news about some of their peaceful nuclear explosions (PNEs) the Soviets have never before published such a body of information.To estimate the seismic yield of a nuclear explosion it is necessary to obtain a calibrated magnitude-yield relationship based on events with known yields and with a consistent set of seismic magnitudes. U.S. estimation of Soviet test yields has been done through application of relationships to the Soviet sites based on the U.S. experience at the Nevada Test Site (NTS), making some correction for differences due to attenuation and near-source coupling of seismic waves.

Implementing and testing theoretical fission fragment yields in a Hauser-Feshbach statistical decay framework

NASA Astrophysics Data System (ADS)

Jaffke, Patrick; Möller, Peter; Stetcu, Ionel; Talou, Patrick; Schmitt, Christelle

2018-03-01

We implement fission fragment yields, calculated using Brownian shape-motion on a macroscopic-microscopic potential energy surface in six dimensions, into the Hauser-Feshbach statistical decay code CGMF. This combination allows us to test the impact of utilizing theoretically-calculated fission fragment yields on the subsequent prompt neutron and γ-ray emission. We draw connections between the fragment yields and the total kinetic energy TKE of the fission fragments and demonstrate that the use of calculated yields can introduce a difference in the 〈TKE〉 and, thus, the prompt neutron multiplicity v, as compared with experimental fragment yields. We deduce the uncertainty on the 〈TKE〉 and v from this procedure and identify possible applications.

Evolutionary agroecology: individual fitness and population yield in wheat (Triticum aestivum).

PubMed

Weiner, Jacob; Du, Yan-Lei; Zhang, Cong; Qin, Xiao-Liang; Li, Feng-Min

2017-09-01

Although the importance of group selection in nature is highly controversial, several researchers have argued that plant breeding for agriculture should be based on group selection, because the goal in agriculture is to optimize population production, not individual fitness. A core hypothesis behind this claim is that crop genotypes with the highest individual fitness in a mixture of genotypes will not produce the highest population yield, because fitness is often increased by "selfish" behaviors, which reduce population performance. We tested this hypothesis by growing 35 cultivars of spring wheat (Triticum aestivum L.) in mixtures and monocultures, and analyzing the relationship between population yield in monoculture and individual yield in mixture. The relationship was unimodal, as predicted. The highest-yielding populations were from cultivars that had intermediate fitness, and these produced, on average, 35% higher yields than cultivars with the highest fitness. It is unlikely that plant breeding or genetic engineering can improve traits that natural selection has been optimizing for millions of years, but there is unutilized potential in traits that increase crop yield by decreasing individual fitness. © 2017 by the Ecological Society of America.

Impact of heterozygosity and heterogeneity on cotton lint yield stability: II. Lint yield components

USDA-ARS?s Scientific Manuscript database

In order to determine which yield components may contribute to yield stability, an 18-environment field study was undertaken to observe the mean, standard deviation (SD), and coefficient of variation (CV) for cotton lint yield components in population types that differed for lint yield stability. Th...

Simple agrometeorological models for estimating Guineagrass yield in Southeast Brazil.

PubMed

Pezzopane, José Ricardo Macedo; da Cruz, Pedro Gomes; Santos, Patricia Menezes; Bosi, Cristiam; de Araujo, Leandro Coelho

2014-09-01

The objective of this work was to develop and evaluate agrometeorological models to simulate the production of Guineagrass. For this purpose, we used forage yield from 54 growing periods between December 2004-January 2007 and April 2010-March 2012 in irrigated and non-irrigated pastures in São Carlos, São Paulo state, Brazil (latitude 21°57'42″ S, longitude 47°50'28″ W and altitude 860 m). Initially we performed linear regressions between the agrometeorological variables and the average dry matter accumulation rate for irrigated conditions. Then we determined the effect of soil water availability on the relative forage yield considering irrigated and non-irrigated pastures, by means of segmented linear regression among water balance and relative production variables (dry matter accumulation rates with and without irrigation). The models generated were evaluated with independent data related to 21 growing periods without irrigation in the same location, from eight growing periods in 2000 and 13 growing periods between December 2004-January 2007 and April 2010-March 2012. The results obtained show the satisfactory predictive capacity of the agrometeorological models under irrigated conditions based on univariate regression (mean temperature, minimum temperature and potential evapotranspiration or degreedays) or multivariate regression. The response of irrigation on production was well correlated with the climatological water balance variables (ratio between actual and potential evapotranspiration or between actual and maximum soil water storage). The models that performed best for estimating Guineagrass yield without irrigation were based on minimum temperature corrected by relative soil water storage, determined by the ratio between the actual soil water storage and the soil water holding capacity.irrigation in the same location, in 2000, 2010 and 2011. The results obtained show the satisfactory predictive capacity of the agrometeorological models under

High-resolution 3-D S-wave Tomography of upper crust structures in Yilan Plain from Ambient Seismic Noise

NASA Astrophysics Data System (ADS)

Chen, Kai-Xun; Chen, Po-Fei; Liang, Wen-Tzong; Chen, Li-Wei; Gung, YuanCheng

2015-04-01

The Yilan Plain (YP) in NE Taiwan locates on the western YP of the Okinawa Trough and displays high geothermal gradients with abundant hot springs, likely resulting from magmatism associated with the back-arc spreading as attested by the offshore volcanic island (Kueishantao). YP features NS distinctive characteristics that the South YP exhibits thin top sedimentary layer, high on-land seismicity and significant SE movements, relative those of the northern counterpart. A dense network (~2.5 km station interval) of 89 Texan instruments was deployed in Aug. 2014, covering most of the YP and its vicinity. The ray path coverage density of each 0.015 degree cells are greater than 150 km that could provide the robustness assessment of tomographic results. We analyze ambient noise signals to invert a high-resolution 3D S-wave model for shallow velocity structures in and around YP. The aim is to investigate the velocity anomalies corresponding to geothermal resources and the NS geological distinctions aforementioned. We apply the Welch's method to generate empirical Rayleigh wave Green's functions between two stations records of continuous vertical components. The group velocities of thus derived functions are then obtained by the multiple-filter analysis technique measured at the frequency range between 0.25 and 1 Hz. Finally, we implement a wavelet-based multi-scale parameterization technique to construct 3D model of S-wave velocity. Our first month results exhibit low velocity in the plain, corresponding existing sediments, those of whole YP show low velocity offshore YP and those of high-resolution south YP reveal stark velocity contrast across the Sanshin fault. Key words: ambient seismic noises, Welch's method, S-wave, Yilan Plain

Chemical intervention in plant sugar signalling increases yield and resilience

NASA Astrophysics Data System (ADS)

Griffiths, Cara A.; Sagar, Ram; Geng, Yiqun; Primavesi, Lucia F.; Patel, Mitul K.; Passarelli, Melissa K.; Gilmore, Ian S.; Steven, Rory T.; Bunch, Josephine; Paul, Matthew J.; Davis, Benjamin G.

2016-12-01

The pressing global issue of food insecurity due to population growth, diminishing land and variable climate can only be addressed in agriculture by improving both maximum crop yield potential and resilience. Genetic modification is one potential solution, but has yet to achieve worldwide acceptance, particularly for crops such as wheat. Trehalose-6-phosphate (T6P), a central sugar signal in plants, regulates sucrose use and allocation, underpinning crop growth and development. Here we show that application of a chemical intervention strategy directly modulates T6P levels in planta. Plant-permeable analogues of T6P were designed and constructed based on a ‘signalling-precursor’ concept for permeability, ready uptake and sunlight-triggered release of T6P in planta. We show that chemical intervention in a potent sugar signal increases grain yield, whereas application to vegetative tissue improves recovery and resurrection from drought. This technology offers a means to combine increases in yield with crop stress resilience. Given the generality of the T6P pathway in plants and other small-molecule signals in biology, these studies suggest that suitable synthetic exogenous small-molecule signal precursors can be used to directly enhance plant performance and perhaps other organism function.

Factors Affecting Firm Yield and the Estimation of Firm Yield for Selected Streamflow-Dominated Drinking-Water-Supply Reservoirs in Massachusetts

USGS Publications Warehouse

Waldron, Marcus C.; Archfield, Stacey A.

2006-01-01

Factors affecting reservoir firm yield, as determined by application of the Massachusetts Department of Environmental Protection's Firm Yield Estimator (FYE) model, were evaluated, modified, and tested on 46 streamflow-dominated reservoirs representing 15 Massachusetts drinking-water supplies. The model uses a mass-balance approach to determine the maximum average daily withdrawal rate that can be sustained during a period of record that includes the 1960s drought-of-record. The FYE methodology to estimate streamflow to the reservoir at an ungaged site was tested by simulating streamflow at two streamflow-gaging stations in Massachusetts and comparing the simulated streamflow to the observed streamflow. In general, the FYE-simulated flows agreed well with observed flows. There were substantial deviations from the measured values for extreme high and low flows. A sensitivity analysis determined that the model's streamflow estimates are most sensitive to input values for average annual precipitation, reservoir drainage area, and the soil-retention number-a term that describes the amount of precipitation retained by the soil in the basin. The FYE model currently provides the option of using a 1,000-year synthetic record constructed by randomly sampling 2-year blocks of concurrent streamflow and precipitation records 500 times; however, the synthetic record has the potential to generate records of precipitation and streamflow that do not reflect the worst historical drought in Massachusetts. For reservoirs that do not have periods of drawdown greater than 2 years, the bootstrap does not offer any additional information about the firm yield of a reservoir than the historical record does. For some reservoirs, the use of a synthetic record to determine firm yield resulted in as much as a 30-percent difference between firm-yield values from one simulation to the next. Furthermore, the assumption that the synthetic traces of streamflow are statistically equivalent to the

Quantitative generalizations for catchment sediment yield following forest logging

Treesearch

James C. Bathurst; Andrés Iroumé

2014-01-01

Published data for temperate forests across the world are analyzed to investigate the potential for generalized quantitative expressions of catchment sediment yield impact in the years immediately following logging. Such generalizations would be useful in a variety of forestry and engineering tasks and would aid the spread of knowledge amongst both relevant...

Yield and Water Productivity Responses to Irrigation Cut-off Strategies after Fruit Set Using Stem Water Potential Thresholds in a Super-High Density Olive Orchard

PubMed Central

Ahumada-Orellana, Luis E.; Ortega-Farías, Samuel; Searles, Peter S.; Retamales, Jorge B.

2017-01-01

An increase in the land area dedicated to super-high density olive orchards has occurred in Chile in recent years. Such modern orchards have high irrigation requirements, and optimizing water use is a priority. Moreover, this region presents low water availability, which makes necessary to establish irrigation strategies to improve water productivity. An experiment was conducted during four consecutive growing seasons (2010–2011 to 2013–2014) to evaluate the responses of yield and water productivity to irrigation cut-off strategies. These strategies were applied after fruit set using midday stem water potential (Ψstem) thresholds in a super-high density olive orchard (cv. Arbequina), located in the Pencahue Valley, Maule Region, Chile. The experimental design was completely randomized with four irrigation cut-off treatments based on the Ψstem thresholds and four replicate plots per treatment (five trees per plot). Similar to commercial growing conditions in our region, the Ψstem in the T1 treatment was maintained between -1.4 and -2.2 MPa (100% of actual evapotranspiration), while T2, T3 and T4 treatments did not receive irrigation from fruit set until they reached a Ψstem threshold of approximately -3.5, -5.0, and -6.0 MPa, respectively. Once the specific thresholds were reached, irrigation was restored and maintained as T1 in all treatments until fruits were harvested. Yield and its components were not significantly different between T1 and T2, but fruit yield and total oil yield, fruit weight, and fruit diameter were decreased by the T3 and T4 treatments. Moreover, yield showed a linear response with water stress integral (SΨ), which was strongly influenced by fruit load. Total oil content (%) and pulp/stone ratio were not affected by the different irrigation strategies. Also, fruit and oil water productivities were significantly greater in T1 and T2 than in the T3 and T4. Moreover, the T2, T3, and T4 treatments averaged 37, 51, and 72 days without

Closing the Yield Gap of Sugar Beet in the Netherlands-A Joint Effort.

PubMed

Hanse, Bram; Tijink, Frans G J; Maassen, Jurgen; van Swaaij, Noud

2018-01-01

The reform of the European Union's sugar regime caused potential decreasing beet prices. Therefore, the Speeding Up Sugar Yield (SUSY) project was initiated. At the start, a 3 × 15 target was formulated: in 2015 the national average sugar yield in the Netherlands equals 15 t/ha (60% of the sugar beet potential) and the total variable costs 15 euro/t sugar beet, aspiring a saving on total variable costs and a strong increase in sugar yield. Based on their average sugar yield in 2000-2004, 26 pairs of "type top" (high yielding) and "type average" (average yielding) growers were selected from all sugar beet growing regions in the Netherlands. On the fields of those farmers, all measures of sugar beet cultivation were investigated, including cost calculation and recording phytopathological, agronomical and soil characteristics in 2006 and 2007. Although there was no significant difference in total variable costs, the "type top" growers yielded significantly 20% more sugar in each year compared to the "type average" growers. Therefore, the most profitable strategy for the growers is maximizing sugar yield and optimizing costs. The difference in sugar yield between growers could be explained by pests and diseases (50%), weed control (30%), soil structure (25%) and sowing date (14%), all interacting with each other. The SUSY-project revealed the effect of the grower's management on sugar yield. As a follow up for the SUSY-project, a growers' guide "Suikerbietsignalen" was published, Best Practice study groups of growers were formed and trainings and workshops were given and field days organized. Further, the benchmarking and feedback on the crop management recordings and the extension on variety choice, sowing performance, foliar fungi control and harvest losses were intensified. On the research part, a resistance breaking strain of the Beet Necrotic Yellow Vein Virus (BNYVV) and a new foliar fungus, Stemphylium beticola , were identified and options for control were

Rational design of high-yield and superior-quality rice.

PubMed

Zeng, Dali; Tian, Zhixi; Rao, Yuchun; Dong, Guojun; Yang, Yaolong; Huang, Lichao; Leng, Yujia; Xu, Jie; Sun, Chuan; Zhang, Guangheng; Hu, Jiang; Zhu, Li; Gao, Zhenyu; Hu, Xingming; Guo, Longbiao; Xiong, Guosheng; Wang, Yonghong; Li, Jiayang; Qian, Qian

2017-03-20

Rice (Oryza sativa L.) is a staple food for more than half of the world's population. To meet the ever-increasing demand for food, because of population growth and improved living standards, world rice production needs to double by 2030 1 . The development of new elite rice varieties with high yield and superior quality is challenging for traditional breeding approaches, and new strategies need to be developed. Here, we report the successful development of new elite varieties by pyramiding major genes that significantly contribute to grain quality and yield from three parents over five years. The new varieties exhibit higher yield potential and better grain quality than their parental varieties and the China's leading super-hybrid rice, Liang-you-pai-jiu (LYP9 or Pei-ai 64S/93-11). Our results demonstrate that rational design is a powerful strategy for meeting the challenges of future crop breeding, particularly in pyramiding multiple complex traits.

Using normalized difference vegetation index (NDVI) to estimate sugarcane yield and yield components

USDA-ARS?s Scientific Manuscript database

Sugarcane (Saccharum spp.) yield and yield components are important traits for growers and scientists to evaluate and select cultivars. Collection of these yield data would be labor intensive and time consuming in the early selection stages of sugarcane breeding cultivar development programs with a ...

Genetic and molecular bases of yield-associated traits: a translational biology approach between rice and wheat.

PubMed

Valluru, Ravi; Reynolds, Matthew P; Salse, Jerome

2014-07-01

Transferring the knowledge bases between related species may assist in enlarging the yield potential of crop plants. Being cereals, rice and wheat share a high level of gene conservation; however, they differ at metabolic levels as a part of the environmental adaptation resulting in different yield capacities. This review focuses on the current understanding of genetic and molecular regulation of yield-associated traits in both crop species, highlights the similarities and differences and presents the putative knowledge gaps. We focus on the traits associated with phenology, photosynthesis, and assimilate partitioning and lodging resistance; the most important drivers of yield potential. Currently, there are large knowledge gaps in the genetic and molecular control of such major biological processes that can be filled in a translational biology approach in transferring genomics and genetics informations between rice and wheat.

Impacts of aerosol pollutant mitigation on lowland rice yields in China

NASA Astrophysics Data System (ADS)

Zhang, Tianyi; Li, Tao; Yue, Xu; Yang, Xiaoguang

2017-10-01

Aerosol pollution in China is significantly altering radiative transfer processes and is thereby potentially affecting rice photosynthesis and yields. However, the response of rice photosynthesis to aerosol-induced radiative perturbations is still not well understood. Here, we employ a process-based modelling approach to simulate changes in incoming radiation (RAD) and the diffuse radiation fraction (DF) with aerosol mitigation in China and their associated impacts on rice yields. Aerosol reduction has the positive effect of increasing RAD and the negative effect of decreasing DF on rice photosynthesis and yields. In rice production areas where the average RAD during the growing season is lower than 250 W m-2, aerosol reduction is beneficial for higher rice yields, whereas in areas with RAD>250 W m-2, aerosol mitigation causes yield declines due to the associated reduction in the DF, which decreases the light use efficiency. As a net effect, rice yields were estimated to significantly increase by 0.8%-2.6% with aerosol concentrations reductions from 20 to 100%, which is lower than the estimates obtained in earlier studies that only considered the effects of RAD. This finding suggests that both RAD and DF are important processes influencing rice yields and should be incorporated into future assessments of agricultural responses to variations in aerosol-induced radiation under climate change.

Biotransformation of β‐hydroxypyruvate and glycolaldehyde to l‐erythrulose by Pichia pastoris strain GS115 overexpressing native transketolase

PubMed Central

Wei, Yu‐Chia; Braun‐Galleani, Stephanie; Henríquez, Maria José; Bandara, Sahan

2017-01-01

Transketolase is a proven biocatalytic tool for asymmetric carbon‐carbon bond formation, both as a purified enzyme and within bacterial whole‐cell biocatalysts. The performance of Pichia pastoris as a host for transketolase whole‐cell biocatalysis was investigated using a transketolase‐overexpressing strain to catalyze formation of l‐erythrulose from β‐hydroxypyruvic acid and glycolaldehyde substrates. Pichia pastoris transketolase coding sequence from the locus PAS_chr1‐4_0150 was subcloned downstream of the methanol‐inducible AOX1 promoter in a plasmid for transformation of strain GS115, generating strain TK150. Whole and disrupted TK150 cells from shake flasks achieved 62% and 65% conversion, respectively, under optimal pH and methanol induction conditions. In a 300 μL reaction, TK150 samples from a 1L fed‐batch fermentation achieved a maximum l‐erythrulose space time yield (STY) of 46.58 g L−1 h−1, specific activity of 155 U gCDW−1, product yield on substrate (Yp/s) of 0.52 mol mol−1 and product yield on catalyst (Yp/x) of 2.23g gCDW−1. We have successfully exploited the rapid growth and high biomass characteristics of Pichia pastoris in whole cell biocatalysis. At high cell density, the engineered TK150 Pichia pastoris strain tolerated high concentrations of substrate and product to achieve high STY of the chiral sugar l‐erythrulose. © 2017 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers Biotechnol. Prog., 34:99–106, 2018 PMID:29086489

Comparison of Fission Product Yields and Their Impact

DOE Office of Scientific and Technical Information (OSTI.GOV)

S. Harrison

2006-02-01

This memorandum describes the Naval Reactors Prime Contractor Team (NRPCT) Space Nuclear Power Program (SNPP) interest in determining the expected fission product yields from a Prometheus-type reactor and assessing the impact of these species on materials found in the fuel element and balance of plant. Theoretical yield calculations using ORIGEN-S and RACER computer models are included in graphical and tabular form in Attachment, with focus on the desired fast neutron spectrum data. The known fission product interaction concerns are the corrosive attack of iron- and nickel-based alloys by volatile fission products, such as cesium, tellurium, and iodine, and the radiologicalmore » transmutation of krypton-85 in the coolant to rubidium-85, a potentially corrosive agent to the coolant system metal piping.« less

Molecular and cytogenetic characterization of a chinese hamster/human hybrid cell line containing a der (21)t(Ypter [yields] cenY::cen21 [yields] 21qter) chromosome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patterson, D.; Hart, I.; Jones, C.

1993-01-01

Human/rodent somatic cell hybrids have been exceedingly useful in assigning human genes and DNA sequences to specific human chromosomes. As new technologies for analyzing the human chromosome complement of such human/rodent hybrid cells become available, it is of critical importance that these be applied to enhance characterization of existing hybrids. This is particularly important since human chromosomes in such hybrids have been observed to rearrange with time. We report here the use of fluorescence in situ hybridization of DNA probes to metaphase chromosomes to analyze one hybrid designated 72532X6. This analysis shows that the chromosome suspected to be a normalmore » human chromosome 21 in this hybrid is actually a translocation chromosome containing Yp and 21 q. In addition, the hybrid contains a fragment of human chromosome 9 translocated to a Chinese hamster chromosome. Analysis of the chromosomes from the human donor indicates that his chromosomes are normal. Thus, this translocation chromosome appears to have arisen after formation of the hybrid. 14 refs., 2 figs.« less

Simultaneous achievement of high ethanol yield and titer in Clostridium thermocellum.

PubMed

Tian, Liang; Papanek, Beth; Olson, Daniel G; Rydzak, Thomas; Holwerda, Evert K; Zheng, Tianyong; Zhou, Jilai; Maloney, Marybeth; Jiang, Nannan; Giannone, Richard J; Hettich, Robert L; Guss, Adam M; Lynd, Lee R

2016-01-01

Biofuel production from plant cell walls offers the potential for sustainable and economically attractive alternatives to petroleum-based products. Fuels from cellulosic biomass are particularly promising, but would benefit from lower processing costs. Clostridium thermocellum can rapidly solubilize and ferment cellulosic biomass, making it a promising candidate microorganism for consolidated bioprocessing for biofuel production, but increases in product yield and titer are still needed. Here, we started with an engineered C. thermocellum strain where the central metabolic pathways to products other than ethanol had been deleted. After two stages of adaptive evolution, an evolved strain was selected with improved yield and titer. On chemically defined medium with crystalline cellulose as substrate, the evolved strain produced 22.4 ± 1.4 g/L ethanol from 60 g/L cellulose. The resulting yield was about 0.39 gETOH/gGluc eq, which is 75 % of the maximum theoretical yield. Genome resequencing, proteomics, and biochemical analysis were used to examine differences between the original and evolved strains. A two step selection method successfully improved the ethanol yield and the titer. This evolved strain has the highest ethanol yield and titer reported to date for C. thermocellum, and is an important step in the development of this microbe for industrial applications.

A spectral-spatial-dynamic hierarchical Bayesian (SSD-HB) model for estimating soybean yield

NASA Astrophysics Data System (ADS)

Kazama, Yoriko; Kujirai, Toshihiro

2014-10-01

A method called a "spectral-spatial-dynamic hierarchical-Bayesian (SSD-HB) model," which can deal with many parameters (such as spectral and weather information all together) by reducing the occurrence of multicollinearity, is proposed. Experiments conducted on soybean yields in Brazil fields with a RapidEye satellite image indicate that the proposed SSD-HB model can predict soybean yield with a higher degree of accuracy than other estimation methods commonly used in remote-sensing applications. In the case of the SSD-HB model, the mean absolute error between estimated yield of the target area and actual yield is 0.28 t/ha, compared to 0.34 t/ha when conventional PLS regression was applied, showing the potential effectiveness of the proposed model.

Yield response and economics of shallow subsurface drip irrigation systems

USDA-ARS?s Scientific Manuscript database

Field tests were conducted using shallow subsurface drip irrigation (S3DI) on cotton (Gossypium hirsutum, L.), corn (Zea mays, L.), and peanut (Arachis hypogeae, L.) in rotation to investigate yield potential and economic sustainability of this irrigation system technique over a six year period. Dri...

Diagnostic yield of hair and urine toxicology testing in potential child abuse cases.

PubMed

Stauffer, Stephanie L; Wood, Stephanie M; Krasowski, Matthew D

2015-07-01

Detection of drugs in a child may be the first objective finding that can be reported in cases of suspected child abuse. Hair and urine toxicology testing, when performed as part of the initial clinical evaluation for suspected child abuse or maltreatment, may serve to facilitate the identification of at-risk children. Furthermore, significant environmental exposure to a drug (considered by law to constitute child abuse in some states) may be identified by toxicology testing of unwashed hair specimens. In order to determine the clinical utility of hair and urine toxicology testing in this population we performed a retrospective chart review on all children for whom hair toxicology testing was ordered at our academic medical center between January 2004 and April 2014. The medical records of 616 children aged 0-17.5 years were reviewed for injury history, previous medication and illicit drug use by caregiver(s), urine drug screen result (if performed), hair toxicology result, medication list, and outcome of any child abuse evaluation. Hair toxicology testing was positive for at least one compound in 106 cases (17.2%), with unexplained drugs in 82 cases (13.3%). Of these, there were 48 cases in which multiple compounds (including combination of parent drugs and/or metabolites within the same drug class) were identified in the sample of one patient. The compounds most frequently identified in the hair of our study population included cocaine, benzoylecgonine, native (unmetabolized) tetrahydrocannabinol, and methamphetamine. There were 68 instances in which a parent drug was identified in the hair without any of its potential metabolites, suggesting environmental exposure. Among the 82 cases in which hair toxicology testing was positive for unexplained drugs, a change in clinical outcome was noted in 71 cases (86.5%). Urine drug screens (UDS) were performed in 457 of the 616 reviewed cases. Of these, over 95% of positive UDS results could be explained by iatrogenic drug

Understanding yield loss and pathogen biology to improve disease management: Stagonospora nodorum blotch - a case study in wheat

USDA-ARS?s Scientific Manuscript database

The estimated potential yield losses caused by plant pathogens are up to 16% globally, and most research in plant pathology aims to reduce yield loss in crops directly or indirectly. Yield losses caused by a certain disease depend not only on disease severity, but also on weather factors, the pathog...

The Effects of Low-Shear Mechanical Stress on Yersinia pestis Virulence

NASA Astrophysics Data System (ADS)

Lawal, Abidat; Jejelowo, Olufisayo A.; Rosenzweig, Jason A.

2010-11-01

Manned space exploration has created a need to evaluate the effects of spacelike stress on pathogenic and opportunistic microbes astronauts could carry with them to the International Space Station and beyond. Yersinia pestis (YP) causes bubonic, septicemic, and pneumonic plague and is capable of killing infected patients within 3-7 days. In this study, low-shear modeled microgravity (LSMMG), a spacelike stress, was used to physically stress YP; and its effects on proliferation, cold growth, and type III secretion system (T3SS) function were evaluated. YP was grown to saturation in either LSMMG or normal gravity (NG) conditions prior to being used for RAW 246.7 cell infections, HeLa cell infections, and Yop secretion assays. A mutant strain of YP (ΔyopB) that lacks the ability to inject Yersinia outer membrane proteins (Yops) into the host cell was used as a negative control in cell infection experiments. Our experimental results indicate that YP cultivated under LSMMG resulted in reduced YopM production and secretion compared to its NG-grown counterpart. Similarly, NG-grown YP induced more cell rounding in HeLa cells than did the LSMMG-grown YP, which suggests that LSMMG somehow impairs T3SS optimum function. Also, LSMMG-grown YP used to infect cultured RAW 246.7 cells showed a similar pattern of dysfunction in that it proliferated less than did its NG-grown counterpart during an 8-hour infection period. This study suggests that LSMMG can attenuate bacterial virulence contrary to previously published data that have demonstrated LSMMG-induced hypervirulence of other Gram-negative enterics.

Impact of age on efficacy of postoperative oxaliplatin-based chemotherapy in patients with rectal cancer after neoadjuvant chemoradiotherapy.

PubMed

Huang, Xuan-Zhang; Gao, Peng; Song, Yong-Xi; Sun, Jing-Xu; Chen, Xiao-Wan; Zhao, Jun-Hua; Ma, Bin; Wang, Jun; Wang, Zhen-Ning

2016-04-12

Clinical practice guidelines focusing on age-related adjuvant chemotherapy for rectal cancer are currently limited. The present study aimed to explore the impact of age on the efficacy of adjuvant oxaliplatin-based chemotherapy in patients with rectal cancer after neoadjuvant chemoradiotherapy. We performed a retrospective cohort analysis using data from the Surveillance, Epidemiology, and End Results-Medicare-linked database from 1992-2009. We enrolled patients with yp stages I-III rectal cancer who received neoadjuvant chemoradiotherapy and underwent curative resection. The age-related survival benefit of adding oxaliplatin to adjuvant 5-fluorouracil (5-FU) chemotherapy was evaluated using Kaplan-Meier survival analysis with propensity score-matching and Cox proportional hazards models. Comparing the oxaliplatin group with the 5-FU group, there were significant interactions between age and chemotherapy efficacy in terms of overall survival (OS) (p for interaction = 0.017) among patients with positive lymph nodes (ypN+). Adding oxaliplatin to 5-FU could prolong survival in patients aged < 73 years and ypN+ category, and but did not translate into survival benefits in patients aged ≥ 73 years and ypN+ category. No significant interactions were observed among ypN- patients, and oxaliplatin did not significantly improve OS, regardless of age. In patients with rectal cancer who have already received neoadjuvant chemoradiotherapy and undergone curative resection, adding oxaliplatin to 5-FU could prolong OS in patients aged < 73 years and ypN+ category. However, adding oxaliplatin did not translate into survival benefits in patients age ≥ 73 years and ypN+ category, or in ypN- patients.

The effects of low-shear mechanical stress on Yersinia pestis virulence.

PubMed

Lawal, Abidat; Jejelowo, Olufisayo A; Rosenzweig, Jason A

2010-11-01

Manned space exploration has created a need to evaluate the effects of spacelike stress on pathogenic and opportunistic microbes astronauts could carry with them to the International Space Station and beyond. Yersinia pestis (YP) causes bubonic, septicemic, and pneumonic plague and is capable of killing infected patients within 3-7 days. In this study, low-shear modeled microgravity (LSMMG), a spacelike stress, was used to physically stress YP; and its effects on proliferation, cold growth, and type III secretion system (T3SS) function were evaluated. YP was grown to saturation in either LSMMG or normal gravity (NG) conditions prior to being used for RAW 246.7 cell infections, HeLa cell infections, and Yop secretion assays. A mutant strain of YP (ΔyopB) that lacks the ability to inject Yersinia outer membrane proteins (Yops) into the host cell was used as a negative control in cell infection experiments. Our experimental results indicate that YP cultivated under LSMMG resulted in reduced YopM production and secretion compared to its NG-grown counterpart. Similarly, NG-grown YP induced more cell rounding in HeLa cells than did the LSMMG-grown YP, which suggests that LSMMG somehow impairs T3SS optimum function. Also, LSMMG-grown YP used to infect cultured RAW 246.7 cells showed a similar pattern of dysfunction in that it proliferated less than did its NG-grown counterpart during an 8-hour infection period. This study suggests that LSMMG can attenuate bacterial virulence contrary to previously published data that have demonstrated LSMMG-induced hypervirulence of other Gram-negative enterics.

Commercial Crop Yields Reveal Strengths and Weaknesses for Organic Agriculture in the United States.

PubMed

Kniss, Andrew R; Savage, Steven D; Jabbour, Randa

2016-01-01

Land area devoted to organic agriculture has increased steadily over the last 20 years in the United States, and elsewhere around the world. A primary criticism of organic agriculture is lower yield compared to non-organic systems. Previous analyses documenting the yield deficiency in organic production have relied mostly on data generated under experimental conditions, but these studies do not necessarily reflect the full range of innovation or practical limitations that are part of commercial agriculture. The analysis we present here offers a new perspective, based on organic yield data collected from over 10,000 organic farmers representing nearly 800,000 hectares of organic farmland. We used publicly available data from the United States Department of Agriculture to estimate yield differences between organic and conventional production methods for the 2014 production year. Similar to previous work, organic crop yields in our analysis were lower than conventional crop yields for most crops. Averaged across all crops, organic yield averaged 67% of conventional yield [corrected]. However, several crops had no significant difference in yields between organic and conventional production, and organic yields surpassed conventional yields for some hay crops. The organic to conventional yield ratio varied widely among crops, and in some cases, among locations within a crop. For soybean (Glycine max) and potato (Solanum tuberosum), organic yield was more similar to conventional yield in states where conventional yield was greatest. The opposite trend was observed for barley (Hordeum vulgare), wheat (Triticum aestevum), and hay crops, however, suggesting the geographical yield potential has an inconsistent effect on the organic yield gap.

Commercial Crop Yields Reveal Strengths and Weaknesses for Organic Agriculture in the United States

PubMed Central

Savage, Steven D.; Jabbour, Randa

2016-01-01

Land area devoted to organic agriculture has increased steadily over the last 20 years in the United States, and elsewhere around the world. A primary criticism of organic agriculture is lower yield compared to non-organic systems. Previous analyses documenting the yield deficiency in organic production have relied mostly on data generated under experimental conditions, but these studies do not necessarily reflect the full range of innovation or practical limitations that are part of commercial agriculture. The analysis we present here offers a new perspective, based on organic yield data collected from over 10,000 organic farmers representing nearly 800,000 hectares of organic farmland. We used publicly available data from the United States Department of Agriculture to estimate yield differences between organic and conventional production methods for the 2014 production year. Similar to previous work, organic crop yields in our analysis were lower than conventional crop yields for most crops. Averaged across all crops, organic yield averaged 80% of conventional yield. However, several crops had no significant difference in yields between organic and conventional production, and organic yields surpassed conventional yields for some hay crops. The organic to conventional yield ratio varied widely among crops, and in some cases, among locations within a crop. For soybean (Glycine max) and potato (Solanum tuberosum), organic yield was more similar to conventional yield in states where conventional yield was greatest. The opposite trend was observed for barley (Hordeum vulgare), wheat (Triticum aestevum), and hay crops, however, suggesting the geographical yield potential has an inconsistent effect on the organic yield gap. PMID:27552217

Sequential ethanol fermentation and anaerobic digestion increases bioenergy yields from duckweed.

PubMed

Calicioglu, O; Brennan, R A

2018-06-01

The potential for improving bioenergy yields from duckweed, a fast-growing, simple, floating aquatic plant, was evaluated by subjecting the dried biomass directly to anaerobic digestion, or sequentially to ethanol fermentation and then anaerobic digestion, after evaporating ethanol from the fermentation broth. Bioethanol yields of 0.41 ± 0.03 g/g and 0.50 ± 0.01 g/g (glucose) were achieved for duckweed harvested from the Penn State Living-Filter (Lemna obscura) and Eco-Machine™ (Lemna minor/japonica and Wolffia columbiana), respectively. The highest biomethane yield, 390 ± 0.1 ml CH 4 /g volatile solids added, was achieved in a reactor containing fermented duckweed from the Living-Filter at a substrate-to-inoculum (S/I) ratio (i.e., duckweed to microorganism ratio) of 1.0. This value was 51.2% higher than the biomethane yield of a replicate reactor with raw (non-fermented) duckweed. The combined bioethanol-biomethane process yielded 70.4% more bioenergy from duckweed, than if anaerobic digestion had been run alone. Copyright © 2018 Elsevier Ltd. All rights reserved.

Yield: it's now an entitlement

NASA Astrophysics Data System (ADS)

George, Bill

1994-09-01

Only a few years ago, the primary method of cost reduction and productivity improvement in the semiconductor industry was increasing manufacturing yields throughout the process. Many of the remarkable reliability improvements realized over the past decade have come about as a result of actions that were originally taken primarily to improve device yields. Obviously, the practice of productivity improvement through yield enhancement is limited to the attainment of 100% yield, at which point some other mechanism must be employed. Traditionally, new products have been introduced to manufacturing at a point of relative immaturity, and semiconductor producers have relied on the traditional `learning curve' method of yield improvement to attain profitable levels of manufacturing yield. Recently, results of a survey of several fabs by a group of University of California at Berkeley researchers in the Competitive Semiconductor Manufacturing Program indicate that most factories learn at about the same rate after startup, in terms of both line yield and defectivity. If this is indeed generally true, then the most competitive factor is the one that starts with the highest yield, and it is difficult to displace a leader once his lead has been established. The two observations made above carry enormous implications for the semiconductor development or manufacturing professional. First, one must achieve very high yields in order to even play the game. Second, the achievement of competitive yields over time in the life of a factory is determined even before the factory is opened, in the planning and development phase. Third, and perhaps most uncomfortable for those of us who have relied on yield improvement as a cost driver, the winners of the nineties will find new levers to drive costs down, having already gotten the benefit of very high yield. This paper looks at the question of how the winners will achieve the critical measures of success, high initial yield and utilization

Lipids of Rhodotorula mucilaginosa IIPL32 with biodiesel potential: Oil yield, fatty acid profile, fuel properties.

PubMed

Khot, Mahesh; Ghosh, Debashish

2017-04-01

This study analyzes the single cell oil (SCO), fatty acid profile, and biodiesel fuel properties of the yeast Rhodotorula mucilaginosa IIPL32 grown on the pentose fraction of acid pre-treated sugarcane bagasse as a carbon source. The yeast biomass from nitrogen limiting culture conditions (15.3 g L -1 ) was able to give the SCO yield of 0.17 g g -1 of xylose consumed. Acid digestion, cryo-pulverization, direct in situ transesterification, and microwave assisted techniques were evaluated in comparison to the Soxhlet extraction for the total intracellular yeast lipid recovery. The significant differences were observed among the SCO yield of different methods and the in situ transesterification stood out most for effective yeast lipid recovery generating 97.23 mg lipid as FAME per gram dry biomass. The method was fast and consumed lesser solvent with greater FAME yield while accessing most cellular fatty acids present. The yeast lipids showed the major presence of monounsaturated fatty esters (35-55%; 18:1, 16:1) suitable for better ignition quality, oxidative stability, and cold-flow properties of the biodiesel. Analyzed fuel properties (density, kinematic viscosity, cetane number) of the yeast oil were in good agreement with international biodiesel standards. The sugarcane bagasse-derived xylose and the consolidated comparative assessment of lab scale SCO recovery methods highlight the necessity for careful substrate choice and validation of analytical method in yeast oil research. The use of less toxic co-solvents together with solvent recovery and recycling would help improve process economics for sustainable production of biodiesel from the hemicellulosic fraction of cheap renewable sources. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The energetic and nutritional yields from insectivory for Kasekela chimpanzees.

PubMed

O'Malley, Robert C; Power, Michael L

2014-06-01

Insectivory is hypothesized to be an important source of macronutrients, minerals, and vitamins for chimpanzees (Pan troglodytes), yet nutritional data based on actual intake are lacking. Drawing on observations from 2008 to 2010 and recently published nutritional assays, we determined the energy, macronutrient and mineral yields for termite-fishing (Macrotermes), ant-dipping (Dorylus), and ant-fishing (Camponotus) by the Kasekela chimpanzees of Gombe National Park, Tanzania. We also estimated the yields from consumption of weaver ants (Oecophylla) and termite alates (Macrotermes and Pseudacanthotermes). On days when chimpanzees were observed to prey on insects, the time spent in insectivorous behavior ranged from <1 min to over 4 h. After excluding partial bouts and those of <1 min duration, ant-dipping bouts were of significantly shorter duration than the other two forms of tool-assisted insectivory but provided the highest mass intake rate. Termite-fishing bouts were of significantly longer duration than ant-dipping and had a lower mass intake rate, but provided higher mean and maximum mass yields. Ant-fishing bouts were comparable to termite-fishing bouts in duration but had significantly lower mass intake rates. Mean and maximum all-day yields from termite-fishing and ant-dipping contributed to or met estimated recommended intake (ERI) values for a broad array of minerals. The mean and maximum all-day yields of other insects consistently contributed to the ERI only for manganese. All forms of insectivory provided small but probably non-trivial amounts of fat and protein. We conclude that different forms of insectivory have the potential to address different nutritional needs for Kasekela chimpanzees. Other than honeybees, insects have received little attention as potential foods for hominins. Our results suggest that ants and (on a seasonal basis) termites would have been viable sources of fat, high-quality protein and minerals for extinct hominins employing

Impacts of forest restoration on water yield: A systematic review

PubMed Central

Filoso, Solange; Bezerra, Maíra Ometto; Weiss, Katherine C. B.; Palmer, Margaret A.

2017-01-01

Background Enhancing water provision services is a common target in forest restoration projects worldwide due to growing concerns over freshwater scarcity. However, whether or not forest cover expansion or restoration can improve water provision services is still unclear and highly disputed. Purpose The goal of this review is to provide a balanced and impartial assessment of the impacts of forest restoration and forest cover expansion on water yields as informed by the scientific literature. Potential sources of bias on the results of papers published are also examined. Data sources English, Spanish and Portuguese peer-review articles in Agricola, CAB Abstracts, ISI Web of Science, JSTOR, Google Scholar, and SciELO. Databases were searched through 2015. Search terms Intervention terms included forest restoration, regeneration/regrowth, forest second-growth, forestation/afforestation, and forestry. Target terms included water yield/quantity, streamflow, discharge, channel runoff, and annual flow. Study selection and eligibility criteria Articles were pre-selected based on key words in the title, abstract or text. Eligible articles addressed relevant interventions and targets and included quantitative information. Results Most studies reported decreases in water yields following the intervention, while other hydrological benefits have been observed. However, relatively few studies focused specifically on forest restoration, especially with native species, and/or on projects done at large spatial or temporal scales. Information is especially limited for the humid tropics and subtropics. Conclusions and implications of key findings While most studies reported a decrease in water yields, meta-analyses from a sub-set of studies suggest the potential influence of temporal and/or spatial scales on the outcomes of forest cover expansion or restoration projects. Given the many other benefits of forest restoration, improving our understanding of when and why forest

Measurements of branching fraction ratios and CP-asymmetries in suppressed B{sup -}{yields}D({yields}K{sup +}{pi}{sup -})K{sup -} and B{sup -}{yields}D({yields}K{sup +}{pi}{sup -}){pi}{sup -} decays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaltonen, T.; Brucken, E.; Devoto, F.

2011-11-01

We report the first reconstruction in hadron collisions of the suppressed decays B{sup -}{yields}D({yields}K{sup +}{pi}{sup -})K{sup -} and B{sup -}{yields}D({yields}K{sup +}{pi}{sup -}){pi}{sup -}, sensitive to the Cabibbo-Kobayashi-Maskawa phase {gamma}, using data from 7 fb{sup -1} of integrated luminosity collected by the CDF II detector at the Tevatron collider. We reconstruct a signal for the B{sup -}{yields}D({yields}K{sup +}{pi}{sup -})K{sup -} suppressed mode with a significance of 3.2 standard deviations, and measure the ratios of the suppressed to favored branching fractions R(K)=[22.0{+-}8.6(stat){+-}2.6(syst)]x10{sup -3}, R{sup +}(K)=[42.6{+-}13.7(stat){+-}2.8(syst)]x10{sup -3}, R{sup -}(K)=[3.8{+-}10.3(stat){+-}2.7(syst)]x10{sup -3} as well as the direct CP-violating asymmetry A(K)=-0.82{+-}0.44(stat){+-}0.09(syst) of this mode. Corresponding quantitiesmore » for B{sup -}{yields}D({yields}K{sup +}{pi}{sup -}){pi}{sup -} decay are also reported.« less

An assessment of yield gains under climate change due to genetic modification of pearl millet.

PubMed

Singh, Piara; Boote, K J; Kadiyala, M D M; Nedumaran, S; Gupta, S K; Srinivas, K; Bantilan, M C S

2017-12-01

Developing cultivars with traits that can enhance and sustain productivity under climate change will be an important climate smart adaptation option. The modified CSM-CERES-Pearl millet model was used to assess yield gains by modifying plant traits determining crop maturity duration, potential yield and tolerance to drought and heat in pearl millet cultivars grown at six locations in arid (Hisar, Jodhpur, Bikaner) and semi-arid (Jaipur, Aurangabad and Bijapur) tropical India and two locations in semi-arid tropical West Africa (Sadore in Niamey and Cinzana in Mali). In all the study locations the yields decreased when crop maturity duration was decreased by 10% both in current and future climate conditions; however, 10% increase in crop maturity significantly (p<0.05) increased yields at Aurangabad and Bijapur, but not at other locations. Increasing yield potential traits by 10% increased yields under both the climate situations in India and West Africa. Drought tolerance imparted the lowest yield gain at Aurangabad (6%), the highest at Sadore (30%) and intermediate at the other locations under current climate. Under climate change the contribution of drought tolerance to the yield of cultivars either increased or decreased depending upon changes in rainfall of the locations. Yield benefits of heat tolerance substantially increased under climate change at most locations, having the greatest effects at Bikaner (17%) in India and Sadore (13%) in West Africa. Aurangabad and Bijapur locations had no yield advantage from heat tolerance due to their low temperature regimes. Thus drought and heat tolerance in pearl millet increased yields under climate change in both the arid and semi-arid tropical climates with greater benefit in relatively hotter environments. This study will assists the plant breeders in evaluating new promising plant traits of pearl millet for adapting to climate change at the selected locations and other similar environments. Copyright © 2017 The

Adapting the CROPGRO cotton model to simulate cotton biomass and yield under southern root-knot nematode parasitism

USDA-ARS?s Scientific Manuscript database

Cotton (Gossypium hirsutum L.) yield losses by southern root-knot nematode [Meloidogyne incognita (Kofoid & White) Chitwood] (RKN) are usually estimated after significant damage has been caused. However, estimation of potential yield reduction before planting is possible by using crop simulation mod...

Production and characterization of poly(3-hydroxybutyrate) generated by Alcaligenes latus using lactose and whey after acid protein precipitation process.

PubMed

Berwig, Karina Hammel; Baldasso, Camila; Dettmer, Aline

2016-10-01

Whey after acid protein precipitation was used as substrate for PHB production in orbital shaker using Alcaligenes latus. Statistical analysis determined the most appropriate hydroxide for pH neutralization of whey after protein precipitation among NH4OH, KOH and NaOH 10%w/v. The results were compared to those of commercial lactose. A scale-up test in a 4L bioreactor was done at 35°C, 750rpm, 7L/min air flow, and 6.5 pH. The PHB was characterized through Fourier Transform Infrared Spectroscopy, thermogravimetry and differential scanning calorimetry. NH4OH provided the best results for productivity (p), 0.11g/L.h, and for polymer yield, (YP/S), 1.08g/g. The bioreactor experiment resulted in lower p and YP/S. PHB showed maximum degradation temperature (291°C), melting temperature (169°C), and chemical properties similar to those of standard PHB. The use of whey as a substrate for PHB production did not affect significantly the final product quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of Rgb-Based Vegetation Indices from Uav Imagery to Estimate Forage Yield in Grassland

NASA Astrophysics Data System (ADS)

Lussem, U.; Bolten, A.; Gnyp, M. L.; Jasper, J.; Bareth, G.

2018-04-01

Monitoring forage yield throughout the growing season is of key importance to support management decisions on grasslands/pastures. Especially on intensely managed grasslands, where nitrogen fertilizer and/or manure are applied regularly, precision agriculture applications are beneficial to support sustainable, site-specific management decisions on fertilizer treatment, grazing management and yield forecasting to mitigate potential negative impacts. To support these management decisions, timely and accurate information is needed on plant parameters (e.g. forage yield) with a high spatial and temporal resolution. However, in highly heterogeneous plant communities such as grasslands, assessing their in-field variability non-destructively to determine e.g. adequate fertilizer application still remains challenging. Especially biomass/yield estimation, as an important parameter in assessing grassland quality and quantity, is rather laborious. Forage yield (dry or fresh matter) is mostly measured manually with rising plate meters (RPM) or ultrasonic sensors (handheld or mounted on vehicles). Thus the in-field variability cannot be assessed for the entire field or only with potential disturbances. Using unmanned aerial vehicles (UAV) equipped with consumer grade RGB cameras in-field variability can be assessed by computing RGB-based vegetation indices. In this contribution we want to test and evaluate the robustness of RGB-based vegetation indices to estimate dry matter forage yield on a recently established experimental grassland site in Germany. Furthermore, the RGB-based VIs are compared to indices computed from the Yara N-Sensor. The results show a good correlation of forage yield with RGB-based VIs such as the NGRDI with R2 values of 0.62.

Ectopic expression of Arabidopsis Target of Rapamycin (AtTOR) improves water-use efficiency and yield potential in rice

NASA Astrophysics Data System (ADS)

Bakshi, Achala; Moin, Mazahar; Kumar, M. Udaya; Reddy, Aramati Bindu Madhava; Ren, Maozhi; Datla, Raju; Siddiq, E. A.; Kirti, P. B.

2017-02-01

The target of Rapamycin (TOR) present in all eukaryotes is a multifunctional protein, regulating growth, development, protein translation, ribosome biogenesis, nutrient, and energy signaling. In the present study, ectopic expression of TOR gene of Arabidopsis thaliana in a widely cultivated indica rice resulted in enhanced plant growth under water-limiting conditions conferring agronomically important water-use efficiency (WUE) trait. The AtTOR high expression lines of rice exhibited profuse tillering, increased panicle length, increased plant height, high photosynthetic efficiency, chlorophyll content and low Δ13C. Δ13C, which is inversely related to high WUE, was as low as 17‰ in two AtTOR high expression lines. These lines were also insensitive to the ABA-mediated inhibition of seed germination. The significant upregulation of 15 stress-specific genes in high expression lines indicates their contribution to abiotic stress tolerance. The constitutive expression of AtTOR is also associated with significant transcriptional upregulation of putative TOR complex-1 components, OsRaptor and OsLST8. Glucose-mediated transcriptional activation of AtTOR gene enhanced lateral root formation. Taken together, our findings indicate that TOR, in addition to its multiple cellular functions, also plays an important role in response to abiotic stress and potentially enhances WUE and yield related attributes.

Two-dimensional isobutyl acetate production pathways to improve carbon yield

PubMed Central

Tashiro, Yohei; Desai, Shuchi H.; Atsumi, Shota

2015-01-01

For an economically competitive biological process, achieving high carbon yield of a target chemical is crucial. In biochemical production, pyruvate and acetyl-CoA are primary building blocks. When sugar is used as the sole biosynthetic substrate, acetyl-CoA is commonly generated by pyruvate decarboxylation. However, pyruvate decarboxylation during acetyl-CoA formation limits the theoretical maximum carbon yield (TMCY) by releasing carbon, and in some cases also leads to redox imbalance. To avoid these problems, we describe here the construction of a metabolic pathway that simultaneously utilizes glucose and acetate. Acetate is utilized to produce acetyl-CoA without carbon loss or redox imbalance. We demonstrate the utility of this approach for isobutyl acetate (IBA) production, wherein IBA production with glucose and acetate achieves a higher carbon yield than with either sole carbon source. These results highlight the potential for this multiple carbon source approach to improve the TMCY and balance redox in biosynthetic pathways. PMID:26108471

Energy Potential of Biomass from Conservation Grasslands in Minnesota, USA

PubMed Central

Jungers, Jacob M.; Fargione, Joseph E.; Sheaffer, Craig C.; Wyse, Donald L.; Lehman, Clarence

2013-01-01

Perennial biomass from grasslands managed for conservation of soil and biodiversity can be harvested for bioenergy. Until now, the quantity and quality of harvestable biomass from conservation grasslands in Minnesota, USA, was not known, and the factors that affect bioenergy potential from these systems have not been identified. We measured biomass yield, theoretical ethanol conversion efficiency, and plant tissue nitrogen (N) as metrics of bioenergy potential from mixed-species conservation grasslands harvested with commercial-scale equipment. With three years of data, we used mixed-effects models to determine factors that influence bioenergy potential. Sixty conservation grassland plots, each about 8 ha in size, were distributed among three locations in Minnesota. Harvest treatments were applied annually in autumn as a completely randomized block design. Biomass yield ranged from 0.5 to 5.7 Mg ha−1. May precipitation increased biomass yield while precipitation in all other growing season months showed no affect. Averaged across all locations and years, theoretical ethanol conversion efficiency was 450 l Mg−1 and the concentration of plant N was 7.1 g kg−1, both similar to dedicated herbaceous bioenergy crops such as switchgrass. Biomass yield did not decline in the second or third year of harvest. Across years, biomass yields fluctuated 23% around the average. Surprisingly, forb cover was a better predictor of biomass yield than warm-season grass with a positive correlation with biomass yield in the south and a negative correlation at other locations. Variation in land ethanol yield was almost exclusively due to variation in biomass yield rather than biomass quality; therefore, efforts to increase biomass yield might be more economical than altering biomass composition when managing conservation grasslands for ethanol production. Our measurements of bioenergy potential, and the factors that control it, can serve as parameters for assessing the economic

Mapping Crop Yield and Sow Date Using High Resolution Imagery

NASA Astrophysics Data System (ADS)

Royal, K.

2015-12-01

Keitasha Royal, Meha Jain, Ph.D., David Lobell, Ph.D Mapping Crop Yield and Sow Date Using High Resolution ImageryThe use of satellite imagery in agriculture is becoming increasingly more significant and valuable. Due to the emergence of new satellites, such as Skybox, these satellites provide higher resolution imagery (e.g 1m) therefore improving the ability to map smallholder agriculture. For the smallholder farm dominated area of northern India, Skybox high-resolution satellite imagery can aid in understanding how to improve farm yields. In particular, we are interested in mapping winter wheat in India, as this region produces approximately 80% of the country's wheat crop, which is important given that wheat is a staple crop that provides approximately 20% of household calories. In northeast India, the combination of increased heat stress, limited irrigation access, and the difficulty for farmers to access advanced farming technologies results in farmers only producing about 50% of their potential crop yield. The use of satellite imagery can aid in understanding wheat yields through time and help identify ways to increase crop yields in the wheat belt of India. To translate Skybox satellite data into meaningful information about wheat fields, we examine vegetation indices, such as the normalized difference vegetation index (NDVI), to measure the "greenness" of plants to help determine the health of the crops. We test our ability to predict crop characteristics, like sow date and yield, using vegetation indices of 59 fields for which we have field data in Bihar, India.

Outcomes of Hispanic women with lymph-node positive, HER2 positive breast cancer treated with neoadjuvant chemotherapy and trastuzumab in Mexico.

PubMed

Villarreal-Garza, Cynthia; Soto-Perez-de-Celis, Enrique; Sifuentes, Erika; Ruano, Santiago; Baez-Revueltas, Berenice; Lara-Medina, Fernando; Arce-Salinas, Claudia; Alvarado-Miranda, Alberto; Chavarri-Guerra, Yanin; Caro-Sanchez, Claudia; Castañeda-Soto, Noel; Bargallo-Rocha, Enrique; Mohar, Alejandro

2015-06-01

Evidence regarding the outcomes of Hispanic women with breast cancer is lacking. We analyzed women with HER2+ disease treated with trastuzumab-based neoadjuvant chemotherapy in Mexico. 244 patients were included. Outcomes were compared between patients who achieved pathologic complete response (pCR) (n = 119), or less than pCR (n = 125). Patients with noninvasive (ypT0/is, ypN0) residual disease were also analyzed. 119 (48.8%) patients achieved pCR. pCR was the only factor associated with improved 3 year survival (98.1% vs 92.3%: P = 0.02). Survival was better in patients with ypT0/is, ypN0 response than in those with residual invasive disease (p < 0.01). 3 year survival was 98.1% for patients with pCR and 92.6% for patients with ypTis, ypN0 response (p = 0.64). Response rates to trastuzumab based neoadjuvant chemotherapy in Hispanics mimic that of other ethnic groups. This underlines the fact that access to treatment, rather than ethnicity, is the main prognostic factor in this population. Copyright © 2015 Elsevier Ltd. All rights reserved.

Standardizing of Pathology in Patients Receiving Neoadjuvant Chemotherapy.

PubMed

Bossuyt, Veerle; Symmans, W Fraser

2016-10-01

The use of neoadjuvant systemic therapy for the treatment of breast cancer patients is increasing. Pathologic response in the form of pathologic complete response (pCR) and grading systems of partial response, such as the residual cancer burden (RCB) system, gives valuable prognostic information for patients and is used as a primary endpoint in clinical trials. The breast cancer and pathology communities are responding with efforts to standardize pathology in patients receiving neoadjuvant chemotherapy. In this review, we summarize the challenges that postneoadjuvant systemic therapy surgical specimens pose and how pathologists and the multidisciplinary team can work together to optimize handling of these specimens. Multidisciplinary communication is essential. A single, standardized approach to macroscopic and microscopic pathologic examination makes it possible to provide reliable response information. This approach employs a map of tissue sections to correlate clinical, gross, microscopic, and imaging findings in order to report the presence of pCR (ypT0 ypN0 and ypT0/is ypN0) versus residual disease, the ypT and ypN stage using the current AJCC/UICC staging system, and the RCB.

Recommendations for standardized pathological characterization of residual disease for neoadjuvant clinical trials of breast cancer by the BIG-NABCG collaboration

PubMed Central

Bossuyt, V.; Provenzano, E.; Symmans, W. F.; Boughey, J. C.; Coles, C.; Curigliano, G.; Dixon, J. M.; Esserman, L. J.; Fastner, G.; Kuehn, T.; Peintinger, F.; von Minckwitz, G.; White, J.; Yang, W.; Badve, S.; Denkert, C.; MacGrogan, G.; Penault-Llorca, F.; Viale, G.; Cameron, D.; Earl, Helena; Alba, Emilio; Lluch, Ana; Albanell, Joan; Amos, Keith; Biernat, Wojciech; Bonnefoi, Hervé; Buzdar, Aman; Cane, Paul; Pinder, Sarah; Carson, Lesley; Dickson-Witmer, Diana; Gong, Gyungyub; Green, Jimmy; Hsu, Chih-Yi; Tseng, Ling-Ming; Kroep, Judith; Leitch, A. Marilyn; Sarode, Venetia; Mamounas, Eleftherios; Marcom, Paul Kelly; Nuciforo, Paolo; Paik, Soonmyung; Peg, Vicente; Peston, David; Pierga, Jean-Yves; Quintela-Fandino, Miguel; Salgado, Roberto; Sikov, William; Thomas, Jeremy; Unzeitig, Gary; Wesseling, Jelle

2015-01-01

Neoadjuvant systemic therapy (NAST) provides the unique opportunity to assess response to treatment after months rather than years of follow-up. However, significant variability exists in methods of pathologic assessment of response to NAST, and thus its interpretation for subsequent clinical decisions. Our international multidisciplinary working group was convened by the Breast International Group-North American Breast Cancer Group (BIG-NABCG) collaboration and tasked to recommend practical methods for standardized evaluation of the post-NAST surgical breast cancer specimen for clinical trials that promote accurate and reliable designation of pathologic complete response (pCR) and meaningful characterization of residual disease. Recommendations include multidisciplinary communication; clinical marking of the tumor site (clips); and radiologic, photographic, or pictorial imaging of the sliced specimen, to map the tissue sections and reconcile macroscopic and microscopic findings. The information required to define pCR (ypT0/is ypN0 or ypT0 yp N0), residual ypT and ypN stage using the current AJCC/UICC system, and the Residual Cancer Burden system were recommended for quantification of residual disease in clinical trials. PMID:26019189

Spectral reflectance indices as a selection criterion for yield improvement in wheat

NASA Astrophysics Data System (ADS)

Babar, Md. Ali

2005-11-01

Scope and methods of study. Yield in wheat ( Triticum aestivum L.) is a complex trait and influenced by many environmental factors, and yield improvement is a daunting task for wheat breeders. Spectral reflectance indices (SRIs) have been used to study different physiological traits in wheat. SRIs have the potential to differentiate genotypes for grain yield. SRIs strongly associated with grain yield can be used to achieve effective genetic gain in wheat under different environments. Three experiments (15 adapted genotypes, 25 and 36 random sister lines derived from two different crosses) under irrigated conditions, and three experiments (each with 30 advanced genotypes) under water-limited conditions were conducted in three successive years in Northwest Mexico at the CIMMYT (International Maize and wheat Improvement Center) experimental station. SRIs and different agronomic data were collected for three years, and biomass was harvested for two years. Phenotypic and genetic correlations between SRIs and grain yield, between SRIs and biomass, realized and broad sense heritability, direct and correlated selection responses for grain yield, and SRIs were calculated. Findings and conclusion. Seven SRIs were calculated, and three near infrared based indices (WI, NWI-1 and NWI-2) showed higher level of genetic and phenotypic correlations with grain yield, yield components and biomass than other SRIs (PRI, RNDVI, GNDVI, and SR) under both irrigated and water limiting environments. Moderate to high realized and broad sense heritability, and selection response were demonstrated by the three NIR based indices. High efficiency of correlated response for yield estimation was demonstrated by the three NIR based indices. The ratio between the correlated response to grain yield based on the three NIR based indices and direct selection response for grain yield was very close to one. The NIR based indices showed very high accuracy in selecting superior genotypes for grain yield

Nitrogen rate strategies for reducing yield-scaled nitrous oxide emissions in maize

NASA Astrophysics Data System (ADS)

Zhao, Xu; Nafziger, Emerson D.; Pittelkow, Cameron M.

2017-12-01

Mitigating nitrogen (N) losses from agriculture without negatively impacting crop productivity is a pressing environmental and economic challenge. Reductions in N fertilizer rate are often highlighted as a solution, yet the degree to which crop yields and economic returns may be impacted at the field-level remains unclear, in part due to limited data availability. Farmers are risk averse and potential yield losses may limit the success of voluntary N loss mitigation protocols, thus understanding field-level yield tradeoffs is critical to inform policy development. Using a case study of soil N2O mitigation in the US Midwest, we conducted an ex-post assessment of two economic and two environmental N rate reduction strategies to identify promising practices for maintaining maize yields and economic returns while reducing N2O emissions per unit yield (i.e. yield-scaled emissions) compared to an assumed baseline N input level. Maize yield response data from 201 on-farm N rate experiments were combined with an empirical equation predicting N2O emissions as a function of N rate. Results indicate that the economic strategy aimed at maximizing returns to N (MRTN) led to moderate but consistent reductions in yield-scaled N2O emissions with small negative impacts on yield and slight increases in median returns. The economic optimum N rate strategy reduced yield-scaled N2O emissions in 75% of cases but increased them otherwise, challenging the assumption that this strategy will automatically reduce environmental impacts per unit production. Both environmental strategies, one designed to increase N recovery efficiency and one to balance N inputs with grain N removal, further reduced yield-scaled N2O emissions but were also associated with negative yield penalties and decreased returns. These results highlight the inherent tension between achieving agronomic and economic goals while reducing environmental impacts which is often overlooked in policy discussions. To enable the

Is Yield Increase Sufficient to Achieve Food Security in China?

PubMed Central

Wei, Xing; Zhang, Zhao; Shi, Peijun; Wang, Pin; Chen, Yi; Song, Xiao; Tao, Fulu

2015-01-01

Increasing demand for food, driven by unprecedented population growth and increasing consumption, will keep challenging food security in China. Although cereal yields have substantially improved during the last three decades, whether it will keep thriving to meet the increasing demand is not known yet. Thus, an integrated analysis on the trends of crop yield and cultivated area is essential to better understand current state of food security in China, especially on county scale. So far, yield stagnation has extensively dominated the main cereal-growing areas across China. Rice yield is facing the most severe stagnation that 53.9% counties tracked in the study have stagnated significantly, followed by maize (42.4%) and wheat (41.9%). As another important element for production sustainability, but often neglected is the planted area patterns. It has been further demonstrated that the loss in productive arable land for rice and wheat have dramatically increased the pressure on achieving food security. Not only a great deal of the planted areas have stagnated since 1980, but also collapsed. 48.4% and 54.4% of rice- and wheat-growing counties have lost their cropland areas to varying degrees. Besides, 27.6% and 35.8% of them have retrograded below the level of the 1980s. The combined influence (both loss in yield and area) has determined the crop sustainable production in China to be pessimistic for rice and wheat, and consequently no surprise to find that more than half of counties rank a lower level of production sustainability. Therefore, given the potential yield increase in wheat and maize, as well as substantial area loss of rice and wheat, the possible targeted adaptation measures for both yield and cropping area is required at county scale. Moreover, policies on food trade, alongside advocation of low calorie diets, reducing food loss and waste can help to enhance food security. PMID:25680193

Yield surface evolution for columnar ice

NASA Astrophysics Data System (ADS)

Zhou, Zhiwei; Ma, Wei; Zhang, Shujuan; Mu, Yanhu; Zhao, Shunpin; Li, Guoyu

A series of triaxial compression tests, which has capable of measuring the volumetric strain of the sample, were conducted on columnar ice. A new testing approach of probing the experimental yield surface was performed from a single sample in order to investigate yield and hardening behaviors of the columnar ice under complex stress states. Based on the characteristic of the volumetric strain, a new method of defined the multiaxial yield strengths of the columnar ice is proposed. The experimental yield surface remains elliptical shape in the stress space of effective stress versus mean stress. The effect of temperature, loading rate and loading path in the initial yield surface and deformation properties of the columnar ice were also studied. Subsequent yield surfaces of the columnar ice have been explored by using uniaxial and hydrostatic paths. The evolution of the subsequent yield surface exhibits significant path-dependent characteristics. The multiaxial hardening law of the columnar ice was established experimentally. A phenomenological yield criterion was presented for multiaxial yield and hardening behaviors of the columnar ice. The comparisons between the theoretical and measured results indicate that this current model is capable of giving a reasonable prediction for the multiaxial yield and post-yield properties of the columnar ice subjected to different temperature, loading rate and path conditions.

Sexual health and contraception.

PubMed

Straw, Fiona; Porter, Charlotte

2012-10-01

Sexual health encompasses 'sexual development and reproductive health, as well as the ability to develop and maintain meaningful interpersonal relationships; appreciate one's own body; interact with both genders in respectful and appropriate ways; express affection, love and intimacy in ways consistent with one's own values'. The 2008 WHO Consensus Statement additionally noted that 'responsible adolescent intimate relationships' should be 'consensual, non-exploitative, honest, pleasurable and protected against unintended pregnancy and STDs if any type of intercourse occurs'. Young people (YP) must, therefore, be able to access sexual health information and services that meet their needs. For most YP, interest in sexual activity begins with puberty, and this is associated with increasingly sexualised behaviour, including exploration of themselves and others. Most YP find this a confusing time, and so it is important that health professionals are able to offer advice regarding the wide range of sexual health issues, including sexuality, choice of partner, contraception, risk and management of sexually transmitted infections (STI) in a confident and approachable manner. YP have never had so much choice or information available to them, and this can be confusing for them. There is good evidence that YP who get information from their parents are likely to initiate sexual activity later than their peers who access information from their friends. However, there is also evidence that some YP would prefer to get sexual health information from health professionals. It is therefore imperative that all health professionals who see YP have an awareness of sexual health issues, and know where to signpost YP should they need more specialist sexual health advice and/or treatment. Where appropriate, one-to-one sexual health advice should be provided to YP on how to prevent and get tested for STIs, and how to prevent unwanted pregnancies. Advice should also be given on all methods

Oxaliplatin Plus Dual Inhibition of Thymidilate Synthase During Preoperative Pelvic Radiotherapy for Locally Advanced Rectal Carcinoma: Long-Term Outcome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Avallone, Antonio, E-mail: avalloneantonio@libero.i; Delrio, Paolo; Pecori, Biagio

Purpose: To assess the safety and efficacy of oxaliplatin (OXA) plus dual inhibition of thymidilate synthase during preoperative pelvic radiotherapy (RT) in patients with poor prognosis for rectal carcinoma. Methods and Materials: Sixty-three patients with the following characteristics, a clinical (c) stage T4, cN1-2, or cT3N0 of {<=}5 cm from the anal verge and/or with a circumferential resection margin (CRM) of {<=}5 mm (by magnetic resonance imaging), received three biweekly courses of chemotherapy with OXA, 100 mg/m{sup 2}; raltitrexed (RTX), 2.5 mg/m{sup 2} on day 1, and 5-fluorouracil (5-FU), 900 mg/m{sup 2} (31 patients) or 800 mg/m{sup 2} (32 patients);more » levo-folinic acid (LFA), 250 mg/m{sup 2} on day 2, during pelvic RT (45 Gy). Pathologic response was defined as complete pathological response (ypCR), major (tumor regression grade(TRG) 2 to 3, with ypCRM-ve and ypN-ve) or minor or no response (TRG4 to -5, or ypCRM+ve, or ypN+ve). Adjuvant 5-FU/LFA regimen was given in cases of cT4, ypN+ve, or ypCRM+ve. Results: Overall, neutropenia (40%) and diarrhea (13%) were the most common grade {>=}3 toxicities, and tolerability was better with a 5-FU dose reduction. No significant difference in pathologic response was seen according 5-FU dosage: overall, a ypCR was obtained in 24 (39%) patients, and a major response in 20 (32%) patients. The 5-year probability of freedom from recurrence was 80% (95% confidence interval, 68%-92%); it was 56% for the minor/no response group, while it was around 90% for both the ypCR and the major response group. Conclusions: OXA, RTX, and 5-FU/LFA administered during pelvic RT produced promising early and long-term results in rectal carcinoma patients with poor prognosis. The postoperative treatment strategy applied in our study supports the risk-adapted approach in postoperative management.« less

Climate Change and ENSO Effects on Southeastern US Climate Patterns and Maize Yield.

PubMed

Mourtzinis, Spyridon; Ortiz, Brenda V; Damianidis, Damianos

2016-07-19

Climate change has a strong influence on weather patterns and significantly affects crop yields globally. El Niño Southern Oscillation (ENSO) has a strong influence on the U.S. climate and is related to agricultural production variability. ENSO effects are location-specific and in southeastern U.S. strongly connect with climate variability. When combined with climate change, the effects on growing season climate patterns and crop yields might be greater than expected. In our study, historical monthly precipitation and temperature data were coupled with non-irrigated maize yield data (33-43 years depending on the location) to show a potential yield suppression of ~15% for one °C increase in southeastern U.S. growing season maximum temperature. Yield suppression ranged between -25 and -2% among locations suppressing the southeastern U.S. average yield trend since 1981 by 17 kg ha(-1)year(-1) (~25%), mainly due to year-to-year June temperature anomalies. Yields varied among ENSO phases from 1971-2013, with greater yields observed during El Niño phase. During La Niña years, maximum June temperatures were higher than Neutral and El Niño, whereas June precipitation was lower than El Niño years. Our data highlight the importance of developing location-specific adaptation strategies quantifying both, climate change and ENSO effects on month-specific growing season climate conditions.

Integrated crop management practices for maximizing grain yield of double-season rice crop.

PubMed

Wang, Depeng; Huang, Jianliang; Nie, Lixiao; Wang, Fei; Ling, Xiaoxia; Cui, Kehui; Li, Yong; Peng, Shaobing

2017-01-12

Information on maximum grain yield and its attributes are limited for double-season rice crop grown under the subtropical environment. This study was conducted to examine key characteristics associated with high yielding double-season rice crop through a comparison between an integrated crop management (ICM) and farmers' practice (FP). Field experiments were conducted in the early and late seasons in the subtropical environment of Wuxue County, Hubei Province, China in 2013 and 2014. On average, grain yield in ICM was 13.5% higher than that in FP. A maximum grain yield of 9.40 and 10.53 t ha -1 was achieved under ICM in the early- and late-season rice, respectively. Yield improvement of double-season rice with ICM was achieved with the combined effects of increased plant density and optimized nutrient management. Yield gain of ICM resulted from a combination of increases in sink size due to more panicle number per unit area and biomass production, further supported by the increased leaf area index, leaf area duration, radiation use efficiency, crop growth rate, and total nitrogen uptake compared with FP. Further enhancement in the yield potential of double-season rice should focus on increasing crop growth rate and biomass production through improved and integrated crop management practices.

Drought-Tolerant Corn Hybrids Yield More in Drought-Stressed Environments with No Penalty in Non-stressed Environments

PubMed Central

Adee, Eric; Roozeboom, Kraig; Balboa, Guillermo R.; Schlegel, Alan; Ciampitti, Ignacio A.

2016-01-01

The potential benefit of drought-tolerant (DT) corn (Zea mays L.) hybrids may depend on drought intensity, duration, crop growth stage (timing), and the array of drought tolerance mechanisms present in selected hybrids. We hypothesized that corn hybrids containing DT traits would produce more consistent yields compared to non-DT hybrids in the presence of drought stress. The objective of this study was to define types of production environments where DT hybrids have a yield advantage compared to non-DT hybrids. Drought tolerant and non-DT hybrid pairs of similar maturity were planted in six site-years with different soil types, seasonal evapotranspiration (ET), and vapor pressure deficit (VPD), representing a range of macro-environments. Irrigation regimes and seeding rates were used to create several micro-environments within each macro-environment. Hybrid response to the range of macro and micro-environmental stresses were characterized in terms of water use efficiency, grain yield, and environmental index. Yield advantage of DT hybrids was positively correlated with environment ET and VPD. Drought tolerant hybrids yielded 5 to 7% more than non-DT hybrids in high and medium ET environments (>430 mm ET), corresponding to seasonal VPD greater than 1200 Pa. Environmental index analysis confirmed that DT hybrids were superior in stressful environments. Yield advantage for DT hybrids appeared as yield dropped below 10.8 Mg ha-1 and averaged as much as 0.6–1 Mg ha-1 at the low yield range. Hybrids with DT technology can offer a degree of buffering against drought stress by minimizing yield reduction, but also maintaining a comparable yield potential in high yielding environments. Further studies should focus on the physiological mechanisms presented in the commercially available corn drought tolerant hybrids. PMID:27790237

Simulating crop yield losses in Switzerland for historical and present Tambora climate scenarios

NASA Astrophysics Data System (ADS)

Flückiger, Simon; Brönnimann, Stefan; Holzkämper, Annelie; Fuhrer, Jürg; Krämer, Daniel; Pfister, Christian; Rohr, Christian

2017-07-01

Severe climatic anomalies in summer 1816, partly due to the eruption of Tambora in April 1815, contributed to delayed growth and poor harvests of important crops in Central Europe. Coinciding with adverse socio-economic conditions, this event triggered the last subsistence crisis in the western World. Here, we model reductions in potential crop yields for 1816 and 1817 and address the question, what impact a similar climatic anomaly would have today. We reconstructed daily weather for Switzerland for 1816/17 on a 2 km grid using historical observations and an analogue resampling method. These data were used to simulate potential crop yields for potato, grain maize, and winter barley using the CropSyst model calibrated for current crop cultivars. We also simulated yields for the same weather anomalies, but referenced to a present-day baseline temperature. Results show that reduced temperature delayed growth and harvest considerably, and in combination with reduced solar irradiance led to a substantial reduction (20%-50%) in the potential yield of potato in 1816. Effects on winter barley were smaller. Significant reductions were also modelled for 1817 and were mainly due to a cold late spring. Relative reductions for the present-day scenario for the two crops were almost indistinguishable from the historical ones. An even stronger response was found for maize, which was not yet common in 1816/17. Waterlogging, which we assessed using a stress-day approach, likely added to the simulated reductions. The documented, strong east-west gradient in malnutrition across Switzerland in 1817/18 could not be explained by biophysical yield limitations (though excess-water limitation might have contributed), but rather by economic, political and social factors. This highlights the importance of these factors for a societies’ ability to cope with extreme climate events. While the adaptive capacity of today’s society in Switzerland is much greater than in the early 19th century

A rare SNP mutation in Brachytic2 moderately reduces plant height and increases yield potential in maize.

PubMed

Xing, Anqi; Gao, Yufeng; Ye, Lingfeng; Zhang, Weiping; Cai, Lichun; Ching, Ada; Llaca, Victor; Johnson, Blaine; Liu, Lin; Yang, Xiaohong; Kang, Dingming; Yan, Jianbing; Li, Jiansheng

2015-07-01

Plant height has long been an important agronomic trait in maize breeding. Many plant height QTLs have been reported, but few of these have been cloned. In this study, a major plant height QTL, qph1, was mapped to a 1.6kb interval in Brachytic2 (Br2) coding sequence on maize chromosome 1. A naturally occurring rare SNP in qph1, which resulted in an amino acid substitution, was validated as the causative mutation. QPH1 protein is located in the plasma membrane and polar auxin transport is impaired in the short near-isogenic line RIL88(qph1). Allelism testing showed that the SNP variant in qph1 reduces longitudinal cell number and decreases plant height by 20% in RIL88(qph1) compared to RIL88(QPH1), and is milder than known br2 mutant alleles. The effect of qph1 on plant height is significant and has no or a slight influence on yield in four F2 backgrounds and in six pairs of single-cross hybrids. Moreover, qph1 could reduce plant height when heterozygous, allowing it to be easily employed in maize breeding. Thus, a less-severe allele of a known dwarf mutant explains part of the quantitative variation for plant height and has great potential in maize improvement. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

On-line prediction of yield grade, longissimus muscle area, preliminary yield grade, adjusted preliminary yield grade, and marbling score using the MARC beef carcass image analysis system.

PubMed

Shackelford, S D; Wheeler, T L; Koohmaraie, M

2003-01-01

The present experiment was conducted to evaluate the ability of the U.S. Meat Animal Research Center's beef carcass image analysis system to predict calculated yield grade, longissimus muscle area, preliminary yield grade, adjusted preliminary yield grade, and marbling score under commercial beef processing conditions. In two commercial beef-processing facilities, image analysis was conducted on 800 carcasses on the beef-grading chain immediately after the conventional USDA beef quality and yield grades were applied. Carcasses were blocked by plant and observed calculated yield grade. The carcasses were then separated, with 400 carcasses assigned to a calibration data set that was used to develop regression equations, and the remaining 400 carcasses assigned to a prediction data set used to validate the regression equations. Prediction equations, which included image analysis variables and hot carcass weight, accounted for 90, 88, 90, 88, and 76% of the variation in calculated yield grade, longissimus muscle area, preliminary yield grade, adjusted preliminary yield grade, and marbling score, respectively, in the prediction data set. In comparison, the official USDA yield grade as applied by online graders accounted for 73% of the variation in calculated yield grade. The technology described herein could be used by the beef industry to more accurately determine beef yield grades; however, this system does not provide an accurate enough prediction of marbling score to be used without USDA grader interaction for USDA quality grading.

High pressure thermal hydrolysis as pre-treatment to increase the methane yield during anaerobic digestion of microalgae.

PubMed

Keymer, Philip; Ruffell, Ian; Pratt, Steven; Lant, Paul

2013-03-01

Anaerobic digestion of algal biomass will be an essential component of algal biofuel production systems, yet the methane yield from digestion of algae is typically much lower than the theoretical potential. In this work, high pressure thermal hydrolysis (HPTH) is shown to enhance methane yield during algae digestion. HPTH pre-treatment was applied to both raw algae and algal residue resulting from lipid extraction. HPTH and even the lipid extraction process itself increased methane yield, by 81% and 33% respectively; in combination they increased yield by 110% over that of the raw algae (18L CH4 gVS(-1) substrate). HPTH had little effect on the rate of anaerobic digestion, however lipid extraction enhanced it by 33% over that for raw algae (0.21day(-1)). Digestion resulted in solubilisation of nitrogen (and phosphorous to a lesser degree) in all cases, showing that there is potential for nutrient recycling for algal growth. Copyright © 2013 Elsevier Ltd. All rights reserved.

Impacts of extreme heat and drought on crop yields in China: an assessment by using the DLEM-AG2 model

NASA Astrophysics Data System (ADS)

Zhang, J.; Yang, J.; Pan, S.; Tian, H.

2016-12-01

China is not only one of the major agricultural production countries with the largest population in the world, but it is also the most susceptible to climate change and extreme events. Much concern has been raised about how extreme climate has affected crop yield, which is crucial for China's food supply security. However, the quantitative assessment of extreme heat and drought impacts on crop yield in China has rarely been investigated. By using the Dynamic Land Ecosystem Model (DLEM-AG2), a highly integrated process-based ecosystem model with crop-specific simulation, here we quantified spatial and temporal patterns of extreme climatic heat and drought stress and their impacts on the yields of major food crops (rice, wheat, maize, and soybean) across China during 1981-2015, and further investigated the underlying mechanisms. Simulated results showed that extreme heat and drought stress significantly reduced national cereal production and increased the yield gaps between potential yield and rain-fed yield. The drought stress was the primary factor to reduce crop yields in the semi-arid and arid regions, and extreme heat stress slightly aggravated the yield loss. The yield gap between potential yield and rain-fed yield was larger at locations with lower precipitation. Our results suggest that a large exploitable yield gap in response to extreme climatic heat-drought stress offers an opportunity to increase productivity in China by optimizing agronomic practices, such as irrigation, fertilizer use, sowing density, and sowing date.

Application of a GCM Ensemble Seasonal Climate Forecasts to Crop Yield Prediction in East Africa

NASA Astrophysics Data System (ADS)

Ogutu, G.; Franssen, W.; Supit, I.; Hutjes, R. W. A.

2016-12-01

We evaluated the potential use of ECMWF System-4 seasonal climate forecasts (S4) for impacts analysis over East Africa. Using the 15 member, 7 months ensemble forecasts initiated every month for 1981-2010, we tested precipitation (tp), air temperature (tas) and surface shortwave radiation (rsds) forecast skill against the WATCH forcing Data ERA-Interim (WFDEI) re-analysis and other data. We used these forecasts as input in the WOFOST crop model to predict maize yields. Forecast skill is assessed using anomaly correlation (ACC), Ranked Probability Skill Score (RPSS) and the Relative Operating Curve Skill Score (ROCSS) for MAM, JJA and OND growing seasons. Predicted maize yields (S4-yields) are verified against historical observed FAO and nationally reported (NAT) yield statistics, and yields from the same crop model forced by WFDEI (WFDEI-yields). Predictability of the climate forecasts vary with season, location and lead-time. The OND tp forecasts show skill over a larger area up to three months lead-time compared to MAM and JJA. Upper- and lower-tercile tp forecasts are 20-80% better than climatology. Good tas forecast skill is apparent with three months lead-time. The rsds is less skillful than tp and tas in all seasons when verified against WFDEI but higher against others. S4-forecasts captures ENSO related anomalous years with region dependent skill. Anomalous ENSO influence is also seen in simulated yields. Focussing on the main sowing dates in the northern (July), equatorial (March-April) and southern (December) regions, WFDEI-yields are lower than FAO and NAT but anomalies are comparable. Yield anomalies are predictable 3-months before sowing in most of the regions. Differences in interannual variability in the range of ±40% may be related to sensitivity of WOFOST to drought stress while the ACCs are largely positive ranging from 0.3 to 0.6. Above and below-normal yields are predictable with 2-months lead time. We evidenced a potential use of seasonal

Quantum Yield of Single Surface Plasmons Generated by a Quantum Dot Coupled with a Silver Nanowire.

PubMed

Li, Qiang; Wei, Hong; Xu, Hongxing

2015-12-09

The interactions between surface plasmons (SPs) in metal nanostructures and excitons in quantum emitters (QEs) lead to many interesting phenomena and potential applications that are strongly dependent on the quantum yield of SPs. The difficulty in distinguishing all the possible exciton recombination channels hinders the experimental determination of SP quantum yield. Here, we experimentally measured for the first time the quantum yield of single SPs generated by the exciton-plasmon coupling in a system composed of a single quantum dot and a silver nanowire (NW). By utilizing the SP guiding property of the NW, the decay rates of all the exciton recombination channels, i.e., direct free space radiation channel, SP generation channel, and nonradiative damping channel, are quantitatively obtained. It is determined that the optimum emitter-NW coupling distance for the largest SP quantum yield is about 10 nm, resulting from the different distance-dependent decay rates of the three channels. These results are important for manipulating the coupling between plasmonic nanostructures and QEs and developing on-chip quantum plasmonic devices for potential nanophotonic and quantum information applications.

Static yields and quality issues: Is the agri-environment program the primary driver?

PubMed

Peltonen-Sainio, Pirjo; Salo, Tapio; Jauhiainen, Lauri; Lehtonen, Heikki; Sieviläinen, Elina

2015-10-01

The Finnish agri-environmental program (AEP) has been in operation for 20 years with >90 % farmer commitment. This study aimed to establish whether reduced nitrogen (N) and phosphorus (P) use has impacted spring cereal yields and quality based on comprehensive follow-up studies and long-term experiments. We found that the gap between genetic yield potential and attained yield has increased after the AEP was imposed. However, many contemporary changes in agricultural practices, driven by changes in prices and farm subsidies, also including the AEP, were likely reasons, together with reduced N, but not phosphorus use. Such overall changes in crop management coincided with stagnation or decline in yields and adverse changes in quality, but yield-removed N increased and residual N decreased. Further studies are needed to assess whether all the changes are environmentally, economically, and socially sustainable, and acceptable, in the long run. The concept of sustainable intensification is worth considering as a means to develop northern European agricultural systems to combine environmental benefits with productivity.

Peanut peg strength and post harvest pod scavenging for full phenotypic yield over digging date and variety

USDA-ARS?s Scientific Manuscript database

New peanut cultivars are available with very high yield potential and high levels of disease resistance. With rising input costs and shrinking return margins, all efforts must be made to harvest the full yield produced. Peanut crops are susceptible to high levels of pod loss during digging from a ...

Distinct N2O yields of AOB and AOA driven ammonia oxidation across a range of Oregon forest soils

NASA Astrophysics Data System (ADS)

Tzanakakis, Vasileios; Dörsch, Peter; Taylor, Anne E.; Giguere, Andrew T.; Bakken, Lars R.; Bottomley, Peter J.; Myrold, David D.

2017-04-01

Ammonia oxidation, as the first and limiting step of nitrification, is a critical process in global N cycling and an important source of nitrous oxide (N2O). Previous studies reported strong contrasts in potential nitrification rates and niche separation of ammonia oxidizing bacteria (AOB) and archaea (AOA) in three acid Oregon forest soils depending on tree stands. In the present study we were interested in the potential contribution of AOB and AOA to nitrification-derived N2O in these soils. We performed soil slurry incubations amended with NH4+ and determined the specific N2O yields of AOB and AOA using inhibitor techniques. Despite large differences in edaphic factors, potential nitrification rates, and niche partitioning, AOB- and AOA-mediated nitrification displayed fairly stable and distinct N2O yields. The N2O yields ranged from 0.11 to 0.17% for AOB and from 0.03 to 0.08% for AOA, which is in agreement with findings of previous pure culture and soil studies. Nitrite accumulation was observed in only one soil, upon NH4+ stimulation of AOB growth, without showing any effect on the apparent N2O yield. The partitioning between AOB and AOA activity was strongly affected by soil pH and nitrogen status, but there was no effect of these variables on the group-specific N2O yield. Together, this suggests that N2O yields of different ammonia oxidizing microorganisms are under tight biochemical control and that the potential contribution of nitrification to N2O emission in acid forest soils can be predicted from AOB - AOA partitioning.

Identification of cocoa trees combining high yield potential and resistance to diseases in segregating progenies In Ecuador

USDA-ARS?s Scientific Manuscript database

Diseases and low yielding planting material are the main factors limiting production of “fine” or “flavour” cocoa in Ecuador. This makes it necessary to develop modern varieties capable of overcoming these limitations. During the 1960s and 1970s INIAP tested several progenies from selected crosses...

Isobaric yield ratio difference and Shannon information entropy

NASA Astrophysics Data System (ADS)

Ma, Chun-Wang; Wei, Hui-Ling; Wang, Shan-Shan; Ma, Yu-Gang; Wada, Ryoichi; Zhang, Yan-Li

2015-03-01

The Shannon information entropy theory is used to explain the recently proposed isobaric yield ratio difference (IBD) probe which aims to determine the nuclear symmetry energy. Theoretically, the difference between the Shannon uncertainties carried by isobars in two different reactions (ΔIn21), is found to be equivalent to the difference between the chemical potentials of protons and neutrons of the reactions [the IBD probe, IB- Δ(βμ)21, with β the reverse temperature]. From the viewpoints of Shannon information entropy, the physical meaning of the above chemical potential difference is interpreted by ΔIn21 as denoting the nuclear symmetry energy or density difference between neutrons and protons in reactions more concisely than from the statistical ablation-abrasion model.

Importance of rhizobia in Agriculture: potential of the commercial inoculants and native strains for improving legume yields in different land-use systems

NASA Astrophysics Data System (ADS)

Lesueur, D.; Atieno, M.; Mathu, S.; Herrmann, L.

2012-04-01

Legumes play an important role in the traditional diets of many regions throughout the world because they provide a multitude of benefits to both the soil and other crops grown in combination with them or following them in several cropping systems. The ability of legumes to fix atmospheric nitrogen in association with rhizobia gives them the capacity to grow in very degraded soils. But do we have to systematically inoculate legumes? For example our results suggested that the systematic inoculation of both cowpea and green gram in Kenya with commercial inoculants to improve yields is not really justified, native strains performing better than inoculated strains. But when native rhizobia nodulating legumes are not naturally present, application of rhizobial inoculants is very commonly used. Our results showed that the utilization of effective good-quality rhizobial inoculants by farmers have a real potential to improve legume yields in unfertile soils requesting high applications of mineral fertilizers. For example an effective soybean commercial inoculants was tested in different locations in Kenya (in about 150 farms in 3 mandate areas presenting different soil characteristics and environmental conditions). Application of the rhizobial inoculant significantly increased the soybean yields in all mandate areas (about 75% of the farms). Nodule occupancy analysis showed that a high number of nodules occupied by the inoculated strain did not obviously lead to an increase of soybean production. Soil factors (pH, P, C, N…) seemed to affect the inoculant efficiency whether the strain is occupying the nodules or not. Our statistic analysis showed that soil pH significantly affected nodulation and yield, though the effect was variable depending on the region. We concluded that the competitiveness of rhizobial strains might not be the main factor explaining the effect (or lack of) of legumes inoculation in the field. Another study was aiming to assess if several factors

Trading forests for yields in the Peruvian Amazon

NASA Astrophysics Data System (ADS)

Gibbs, Holly

2012-03-01

Our knowledge of how agriculture expands, and the types of land it replaces, is remarkably limited across the tropics. Most remote-sensing studies focus on the net gains and losses in forests and agricultural land rather than the land-use transition pathways (Gibbs et al 2010). Only a handful of studies identify land sources for new croplands or plantations, and then only for farming systems aggregated together (e.g., Koh and Wilcove 2008, Morton et al 2006, Gibbs et al 2010). Gutiérrez-Vélez et al (2011), however, have taken a leap forward by tracking the different expansion pathways for smallholder and industrial oil palm plantations. Using a combination of Landsat, MODIS and field surveys, they investigate whether higher yields in new agricultural lands spare forests in the Peruvian Amazon and in a smaller focus area in the Ucayali region. Across the Peruvian Amazon, they show that between 2000 and 2010, new high-yield oil palm plantations replaced forests 72% of the time and accounted for 1.3% of total deforestation, with most expansion occurring after 2006. Gutiérrez-Vélez et al went further in the Ucayali region and compared land sources for new high-yield and low-yield plantations. Expansion of higher-yield agricultural lands should logically reduce the total area needed for production, thus potentially sparing forests. In the Ucayali focus area, expansion of high-yield oil palm did convert less total land area but more forest was cleared than with low-yield expansion. Smaller-scale plantations tended to expand into already cleared areas while industrial-scale plantations traded their greater yields for forests, leading to higher land-clearing carbon emissions per production unit (Gibbs et al 2008). Gutiérrez-Vélez et al show that higher yields may require less land for production but more forest may be lost in the process, and they emphasize the need for stronger incentives for land sparing. The potential land-saving nature of these high-yield

Reed canarygrass yield improvement

USDA-ARS?s Scientific Manuscript database

Reed canarygrass is well adapted to the northern USA. Eight cultivars and 72 accessions collected in rural landscapes from Iowa to New Hampshire were evaluated for yield. Accessions produced on average 7% higher biomass yield compared to existing cultivars. Naturalized populations of reed canarygras...

Heterologous Production and Yield Improvement of Epothilones in Burkholderiales Strain DSM 7029.

PubMed

Bian, Xiaoying; Tang, Biao; Yu, Yucong; Tu, Qiang; Gross, Frank; Wang, Hailong; Li, Aiying; Fu, Jun; Shen, Yuemao; Li, Yue-Zhong; Stewart, A Francis; Zhao, Guoping; Ding, Xiaoming; Müller, Rolf; Zhang, Youming

2017-07-21

The cloning of microbial natural product biosynthetic gene clusters and their heterologous expression in a suitable host have proven to be a feasible approach to improve the yield of valuable natural products and to begin mining cryptic natural products in microorganisms. Myxobacteria are a prolific source of novel bioactive natural products with only limited choices of heterologous hosts that have been exploited. Here, we describe the use of Burkholderiales strain DSM 7029 as a potential heterologous host for the functional expression of myxobacterial secondary metabolites. Using a newly established electroporation procedure, the 56 kb epothilone biosynthetic gene cluster from the myxobacterium Sorangium cellulosum was introduced into the chromosome of strain DSM 7029 by transposition. Production of epothilones A, B, C, and D was detected despite their yields being low. Optimization of the medium, introduction of the exogenous methylmalonyl-CoA biosynthetic pathway, and overexpression of rare tRNA genes resulted in an approximately 75-fold increase in the total yields of epothilones to 307 μg L -1 . These results show that strain DSM 7029 has the potential to produce epothilones with reasonable titers and might be a broadly applicable host for the heterologous expression of other myxobacterial polyketide synthases and nonribosomal peptide synthetases, expediting the process of genome mining.

Tradeoffs between water requirements and yield stability in annual vs. perennial crops

NASA Astrophysics Data System (ADS)

Vico, Giulia; Brunsell, Nathaniel A.

2018-02-01

Population growth and changes in climate and diets will likely further increase the pressure on agriculture and water resources globally. Currently, staple crops are obtained from annuals plants. A shift towards perennial crops may enhance many ecosystem services, but at the cost of higher water requirements and lower yields. It is still unclear when the advantages of perennial crops overcome their disadvantages and perennial crops are thus a sustainable solution. Here we combine a probabilistic description of the soil water balance and crop development with an extensive dataset of traits of congeneric annuals and perennials to identify the conditions for which perennial crops are more viable than annual ones with reference to yield, yield stability, and effective use of water. We show that the larger and more developed roots of perennial crops allow a better exploitation of soil water resources and a reduction of yield variability with respect to annual species, but their yields remain lower when considering grain crops. Furthermore, perennial crops have higher and more variable irrigation requirements and lower water productivity. These results are important to understand the potential consequences for yield, its stability, and water resource use of a shift from annual to perennial crops and, more generally, if perennial crops may be more resilient than annual crops in the face of climatic fluctuations.

Linkages among climate change, crop yields and Mexico-US cross-border migration.

PubMed

Feng, Shuaizhang; Krueger, Alan B; Oppenheimer, Michael

2010-08-10

Climate change is expected to cause mass human migration, including immigration across international borders. This study quantitatively examines the linkages among variations in climate, agricultural yields, and people's migration responses by using an instrumental variables approach. Our method allows us to identify the relationship between crop yields and migration without explicitly controlling for all other confounding factors. Using state-level data from Mexico, we find a significant effect of climate-driven changes in crop yields on the rate of emigration to the United States. The estimated semielasticity of emigration with respect to crop yields is approximately -0.2, i.e., a 10% reduction in crop yields would lead an additional 2% of the population to emigrate. We then use the estimated semielasticity to explore the potential magnitude of future emigration. Depending on the warming scenarios used and adaptation levels assumed, with other factors held constant, by approximately the year 2080, climate change is estimated to induce 1.4 to 6.7 million adult Mexicans (or 2% to 10% of the current population aged 15-65 y) to emigrate as a result of declines in agricultural productivity alone. Although the results cannot be mechanically extrapolated to other areas and time periods, our findings are significant from a global perspective given that many regions, especially developing countries, are expected to experience significant declines in agricultural yields as a result of projected warming.

Recommendations for standardized pathological characterization of residual disease for neoadjuvant clinical trials of breast cancer by the BIG-NABCG collaboration.

PubMed

Bossuyt, V; Provenzano, E; Symmans, W F; Boughey, J C; Coles, C; Curigliano, G; Dixon, J M; Esserman, L J; Fastner, G; Kuehn, T; Peintinger, F; von Minckwitz, G; White, J; Yang, W; Badve, S; Denkert, C; MacGrogan, G; Penault-Llorca, F; Viale, G; Cameron, D

2015-07-01

Neoadjuvant systemic therapy (NAST) provides the unique opportunity to assess response to treatment after months rather than years of follow-up. However, significant variability exists in methods of pathologic assessment of response to NAST, and thus its interpretation for subsequent clinical decisions. Our international multidisciplinary working group was convened by the Breast International Group-North American Breast Cancer Group (BIG-NABCG) collaboration and tasked to recommend practical methods for standardized evaluation of the post-NAST surgical breast cancer specimen for clinical trials that promote accurate and reliable designation of pathologic complete response (pCR) and meaningful characterization of residual disease. Recommendations include multidisciplinary communication; clinical marking of the tumor site (clips); and radiologic, photographic, or pictorial imaging of the sliced specimen, to map the tissue sections and reconcile macroscopic and microscopic findings. The information required to define pCR (ypT0/is ypN0 or ypT0 yp N0), residual ypT and ypN stage using the current AJCC/UICC system, and the Residual Cancer Burden system were recommended for quantification of residual disease in clinical trials. © The Author 2015. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Simultaneous achievement of high ethanol yield and titer in Clostridium thermocellum

DOE PAGES

Tian, Liang; Papanek, Beth; Olson, Daniel G.; ...

2016-06-02

Background Biofuel production from plant cell walls offers the potential for sustainable and economically attractive alternatives to petroleum-based products. Fuels from cellulosic biomass are particularly promising, but would benefit from lower processing costs. Clostridium thermocellum can rapidly solubilize and ferment cellulosic biomass, making it a promising candidate microorganism for consolidated bioprocessing for biofuel production, but increases in product yield and titer are still needed. Results We started with an engineered C. thermocellum strain where the central metabolic pathways to products other than ethanol had been deleted. After two stages of adaptive evolution, an evolved strain was selected with improved yieldmore » and titer. On chemically defined medium with crystalline cellulose as substrate, the evolved strain produced 22.4 ± 1.4 g/L ethanol from 60 g/L cellulose. Moreover, the resulting yield was about 0.39 gETOH/gGluc eq, which is 75 % of the maximum theoretical yield. Genome resequencing, proteomics, and biochemical analysis were used to examine differences between the original and evolved strains. Conclusions A two step selection method successfully improved the ethanol yield and the titer. Finaly, this evolved strain has the highest ethanol yield and titer reported to date for C. thermocellum, and is an important step in the development of this microbe for industrial applications.« less

Opposing effects of different soil organic matter fractions on crop yields.

PubMed

Wood, Stephen A; Sokol, Noah; Bell, Colin W; Bradford, Mark A; Naeem, Shahid; Wallenstein, Matthew D; Palm, Cheryl A

2016-10-01

Soil organic matter is critical to sustainable agriculture because it provides nutrients to crops as it decomposes and increases nutrient- and water-holding capacity when built up. Fast- and slow-cycling fractions of soil organic matter can have different impacts on crop production because fast-cycling fractions rapidly release nutrients for short-term plant growth and slow-cycling fractions bind nutrients that mineralize slowly and build up water-holding capacity. We explored the controls on these fractions in a tropical agroecosystem and their relationship to crop yields. We performed physical fractionation of soil organic matter from 48 farms and plots in western Kenya. We found that fast-cycling, particulate organic matter was positively related to crop yields, but did not have a strong effect, while slower-cycling, mineral-associated organic matter was negatively related to yields. Our finding that slower-cycling organic matter was negatively related to yield points to a need to revise the view that stabilization of organic matter positively impacts food security. Our results support a new paradigm that different soil organic matter fractions are controlled by different mechanisms, potentially leading to different relationships with management outcomes, like crop yield. Effectively managing soils for sustainable agriculture requires quantifying the effects of specific organic matter fractions on these outcomes. © 2016 by the Ecological Society of America.

Potential nitrous oxide yield of AOA vs. AOB and utilization of carbon and nitrogen in the ammonia oxidizing process in the Pearl River Estuary

NASA Astrophysics Data System (ADS)

Ma, L.; Dai, M.; Tan, S.; Xia, X.; Liu, H.

2016-12-01

Nitrous oxide (N2O), a greenhouse gas, is a by-product during ammonia oxidation process, the production of which is often stimulated under low dissolved oxygen (DO) in the estuarine environment. The potential yield of N2O has been considered to be driven by ammonia-oxidizing bacteria (AOB) of Betaproteobacteria & Gammaproteobacteria and/or ammonia-oxidizing archaea (AOA) of Thaumarchaeota. In order to examine the relative importance of AOA and AOB in producing N2O and in modulating the potential N2O yield, arch-amoA, beta-amoA, gamma-amoA encoding for the alpha subunit of the ammonia monooxygenase (AMO) are used as biomarkers to identify the distributions and bioactivities of AOA and AOB in the Pearl River Estuary (PRE). Size fractionation experiments were conducted to distinguish AOA and AOB on particles in different size-fractions of > 3 μm, 0.45-3 μm, and 0.22-0.45 μm. Pure culture of N. maritimusSCM1 was studied as a model organism to identify the organic carbon production during ammonia oxidation by SCM1 strains. Our results show that AOA distributes largely in the free-living state and could adapt to very limited ammonia substrate and low saturation of DO; AOB mainly distributes at the particle-attached state under relative richer ammonia and high DO conditions; however, the RNA/DNA ratio of AOB was higher than that of AOA under the same conditions suggesting AOB is relatively more actively expressed. In the upper reach of PRE, the dominant microorganism in the water column was AOB and the in situ N2O/NH3 therein ranged 0.73-3.74 ‰. In the lower PRE, AOA was dominated, and the in situ N2O/NH3 was of 1.17- 7.32‰. At selected sites, we estimated isotope effect (e) of AOA (eDIC/bulk) as -23.94‰ and AOB (eDIC/bulk) as -56.6‰ to -44.8‰, which is consistent with the studies of pure cultures. The coefficient of C sequestration "k", defined as (C biomass / DIC in situ) / (N biomass / ammonia in situ) to differ the utilization of carbon and nitrogen, of

Chemo-selective high yield microwave assisted reaction turns cellulose to green chemicals.

PubMed

Hassanzadeh, Salman; Aminlashgari, Nina; Hakkarainen, Minna

2014-11-04

Exceptionally high cellulose liquefaction yields, up to 87% as calculated from the amount of solid residue, were obtained under mild conditions by utilizing the synergistic effect of microwave radiation and acid catalysis. The effect of processing conditions on degradation products was fingerprinted by rapid laser desorption ionization-mass spectrometry (LDI-MS) method. The reaction was chemo-tunable, enabling production of glucose (Glc) or levulinic acid (LeA) at significantly high selectivity and yields, the relative molar yields being up to 50 and 69%, respectively. A turning point from pure depolymerization to glucose to further degradation to levulinic acid and formic acid was observed at approximately 50% liquefaction or above 140 °C. This was accompanied by the formation of small amounts of solid spherical carbonized residues. The reaction was monitored by multiple analytical techniques. The high yields were connected to the ability of the process to break the strong secondary interactions in cellulose. The developed method has great potential for future production of green platform chemicals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Secondary electron emission yield from high aspect ratio carbon velvet surfaces

NASA Astrophysics Data System (ADS)

Jin, Chenggang; Ottaviano, Angelica; Raitses, Yevgeny

2017-11-01

The plasma electrons bombarding a plasma-facing wall surface can induce secondary electron emission (SEE) from the wall. A strong SEE can enhance the power losses by reducing the wall sheath potential and thereby increasing the electron flux from the plasma to the wall. The use of the materials with surface roughness and the engineered materials with surface architecture is known to reduce the effective SEE by trapping the secondary electrons. In this work, we demonstrate a 65% reduction of SEE yield using a velvet material consisting of high aspect ratio carbon fibers. The measurements of SEE yield for different velvet samples using the electron beam in vacuum demonstrate the dependence of the SEE yield on the fiber length and the packing density, which is strongly affected by the alignment of long velvet fibers with respect to the electron beam impinging on the velvet sample. The results of SEE measurements support the previous observations of the reduced SEE measured in Hall thrusters.

Yield enhancement with DFM

NASA Astrophysics Data System (ADS)

Paek, Seung Weon; Kang, Jae Hyun; Ha, Naya; Kim, Byung-Moo; Jang, Dae-Hyun; Jeon, Junsu; Kim, DaeWook; Chung, Kun Young; Yu, Sung-eun; Park, Joo Hyun; Bae, SangMin; Song, DongSup; Noh, WooYoung; Kim, YoungDuck; Song, HyunSeok; Choi, HungBok; Kim, Kee Sup; Choi, Kyu-Myung; Choi, Woonhyuk; Jeon, JoongWon; Lee, JinWoo; Kim, Ki-Su; Park, SeongHo; Chung, No-Young; Lee, KangDuck; Hong, YoungKi; Kim, BongSeok

2012-03-01

A set of design for manufacturing (DFM) techniques have been developed and applied to 45nm, 32nm and 28nm logic process technologies. A noble technology combined a number of potential confliction of DFM techniques into a comprehensive solution. These techniques work in three phases for design optimization and one phase for silicon diagnostics. In the DFM prevention phase, foundation IP such as standard cells, IO, and memory and P&R tech file are optimized. In the DFM solution phase, which happens during ECO step, auto fixing of process weak patterns and advanced RC extraction are performed. In the DFM polishing phase, post-layout tuning is done to improve manufacturability. DFM analysis enables prioritization of random and systematic failures. The DFM technique presented in this paper has been silicon-proven with three successful tape-outs in Samsung 32nm processes; about 5% improvement in yield was achieved without any notable side effects. Visual inspection of silicon also confirmed the positive effect of the DFM techniques.

Similar Estimates of Temperature Impacts on Global Wheat Yield by Three Independent Methods

NASA Technical Reports Server (NTRS)

Liu, Bing; Asseng, Senthold; Muller, Christoph; Ewart, Frank; Elliott, Joshua; Lobell, David B.; Martre, Pierre; Ruane, Alex C.; Wallach, Daniel; Jones, James W.;

Similar estimates of temperature impacts on global wheat yield by three independent methods

NASA Astrophysics Data System (ADS)

Liu, Bing; Asseng, Senthold; Müller, Christoph; Ewert, Frank; Elliott, Joshua; Lobell, David B.; Martre, Pierre; Ruane, Alex C.; Wallach, Daniel; Jones, James W.; Rosenzweig, Cynthia; Aggarwal, Pramod K.; Alderman, Phillip D.; Anothai, Jakarat; Basso, Bruno; Biernath, Christian; Cammarano, Davide; Challinor, Andy; Deryng, Delphine; Sanctis, Giacomo De; Doltra, Jordi; Fereres, Elias; Folberth, Christian; Garcia-Vila, Margarita; Gayler, Sebastian; Hoogenboom, Gerrit; Hunt, Leslie A.; Izaurralde, Roberto C.; Jabloun, Mohamed; Jones, Curtis D.; Kersebaum, Kurt C.; Kimball, Bruce A.; Koehler, Ann-Kristin; Kumar, Soora Naresh; Nendel, Claas; O'Leary, Garry J.; Olesen, Jørgen E.; Ottman, Michael J.; Palosuo, Taru; Prasad, P. V. Vara; Priesack, Eckart; Pugh, Thomas A. M.; Reynolds, Matthew; Rezaei, Ehsan E.; Rötter, Reimund P.; Schmid, Erwin; Semenov, Mikhail A.; Shcherbak, Iurii; Stehfest, Elke; Stöckle, Claudio O.; Stratonovitch, Pierre; Streck, Thilo; Supit, Iwan; Tao, Fulu; Thorburn, Peter; Waha, Katharina; Wall, Gerard W.; Wang, Enli; White, Jeffrey W.; Wolf, Joost; Zhao, Zhigan; Zhu, Yan

2016-12-01

The potential impact of global temperature change on global crop yield has recently been assessed with different methods. Here we show that grid-based and point-based simulations and statistical regressions (from historic records), without deliberate adaptation or CO2 fertilization effects, produce similar estimates of temperature impact on wheat yields at global and national scales. With a 1 °C global temperature increase, global wheat yield is projected to decline between 4.1% and 6.4%. Projected relative temperature impacts from different methods were similar for major wheat-producing countries China, India, USA and France, but less so for Russia. Point-based and grid-based simulations, and to some extent the statistical regressions, were consistent in projecting that warmer regions are likely to suffer more yield loss with increasing temperature than cooler regions. By forming a multi-method ensemble, it was possible to quantify `method uncertainty’ in addition to model uncertainty. This significantly improves confidence in estimates of climate impacts on global food security.

Satellite-based assessment of yield variation and its determinants in smallholder African systems

PubMed Central

Lobell, David B.

2017-01-01

The emergence of satellite sensors that can routinely observe millions of individual smallholder farms raises possibilities for monitoring and understanding agricultural productivity in many regions of the world. Here we demonstrate the potential to track smallholder maize yield variation in western Kenya, using a combination of 1-m Terra Bella imagery and intensive field sampling on thousands of fields over 2 y. We find that agreement between satellite-based and traditional field survey-based yield estimates depends significantly on the quality of the field-based measures, with agreement highest (R2 up to 0.4) when using precise field measures of plot area and when using larger fields for which rounding errors are smaller. We further show that satellite-based measures are able to detect positive yield responses to fertilizer and hybrid seed inputs and that the inferred responses are statistically indistinguishable from estimates based on survey-based yields. These results suggest that high-resolution satellite imagery can be used to make predictions of smallholder agricultural productivity that are roughly as accurate as the survey-based measures traditionally used in research and policy applications, and they indicate a substantial near-term potential to quickly generate useful datasets on productivity in smallholder systems, even with minimal or no field training data. Such datasets could rapidly accelerate learning about which interventions in smallholder systems have the most positive impact, thus enabling more rapid transformation of rural livelihoods. PMID:28202728

Satellite-based assessment of yield variation and its determinants in smallholder African systems.

PubMed

Burke, Marshall; Lobell, David B

2017-02-28

The emergence of satellite sensors that can routinely observe millions of individual smallholder farms raises possibilities for monitoring and understanding agricultural productivity in many regions of the world. Here we demonstrate the potential to track smallholder maize yield variation in western Kenya, using a combination of 1-m Terra Bella imagery and intensive field sampling on thousands of fields over 2 y. We find that agreement between satellite-based and traditional field survey-based yield estimates depends significantly on the quality of the field-based measures, with agreement highest ([Formula: see text] up to 0.4) when using precise field measures of plot area and when using larger fields for which rounding errors are smaller. We further show that satellite-based measures are able to detect positive yield responses to fertilizer and hybrid seed inputs and that the inferred responses are statistically indistinguishable from estimates based on survey-based yields. These results suggest that high-resolution satellite imagery can be used to make predictions of smallholder agricultural productivity that are roughly as accurate as the survey-based measures traditionally used in research and policy applications, and they indicate a substantial near-term potential to quickly generate useful datasets on productivity in smallholder systems, even with minimal or no field training data. Such datasets could rapidly accelerate learning about which interventions in smallholder systems have the most positive impact, thus enabling more rapid transformation of rural livelihoods.

Mouse Y-linked Zfy1 and Zfy2 are expressed during the male-specific interphase between meiosis I and meiosis II and promote the 2nd meiotic division.

PubMed

Vernet, Nadège; Mahadevaiah, Shantha K; Yamauchi, Yasuhiro; Decarpentrie, Fanny; Mitchell, Michael J; Ward, Monika A; Burgoyne, Paul S

2014-06-01

Mouse Zfy1 and Zfy2 encode zinc finger transcription factors that map to the short arm of the Y chromosome (Yp). They have previously been shown to promote meiotic quality control during pachytene (Zfy1 and Zfy2) and at the first meiotic metaphase (Zfy2). However, from these previous studies additional roles for genes encoded on Yp during meiotic progression were inferred. In order to identify these genes and investigate their function in later stages of meiosis, we created three models with diminishing Yp and Zfy gene complements (but lacking the Y-long-arm). Since the Y-long-arm mediates pairing and exchange with the X via their pseudoautosomal regions (PARs) we added a minute PAR-bearing X chromosome derivative to enable formation of a sex bivalent, thus avoiding Zfy2-mediated meiotic metaphase I (MI) checkpoint responses to the unpaired (univalent) X chromosome. Using these models we obtained definitive evidence that genetic information on Yp promotes meiosis II, and by transgene addition identified Zfy1 and Zfy2 as the genes responsible. Zfy2 was substantially more effective and proved to have a much more potent transactivation domain than Zfy1. We previously established that only Zfy2 is required for the robust apoptotic elimination of MI spermatocytes in response to a univalent X; the finding that both genes potentiate meiosis II led us to ask whether there was de novo Zfy1 and Zfy2 transcription in the interphase between meiosis I and meiosis II, and this proved to be the case. X-encoded Zfx was also expressed at this stage and Zfx over-expression also potentiated meiosis II. An interphase between the meiotic divisions is male-specific and we previously hypothesised that this allows meiosis II critical X and Y gene reactivation following sex chromosome silencing in meiotic prophase. The interphase transcription and meiosis II function of Zfx, Zfy1 and Zfy2 validate this hypothesis.

Mouse Y-Linked Zfy1 and Zfy2 Are Expressed during the Male-Specific Interphase between Meiosis I and Meiosis II and Promote the 2nd Meiotic Division

PubMed Central

Vernet, Nadège; Mahadevaiah, Shantha K.; Yamauchi, Yasuhiro; Decarpentrie, Fanny; Mitchell, Michael J.; Ward, Monika A.; Burgoyne, Paul S.

2014-01-01

Mouse Zfy1 and Zfy2 encode zinc finger transcription factors that map to the short arm of the Y chromosome (Yp). They have previously been shown to promote meiotic quality control during pachytene (Zfy1 and Zfy2) and at the first meiotic metaphase (Zfy2). However, from these previous studies additional roles for genes encoded on Yp during meiotic progression were inferred. In order to identify these genes and investigate their function in later stages of meiosis, we created three models with diminishing Yp and Zfy gene complements (but lacking the Y-long-arm). Since the Y-long-arm mediates pairing and exchange with the X via their pseudoautosomal regions (PARs) we added a minute PAR-bearing X chromosome derivative to enable formation of a sex bivalent, thus avoiding Zfy2-mediated meiotic metaphase I (MI) checkpoint responses to the unpaired (univalent) X chromosome. Using these models we obtained definitive evidence that genetic information on Yp promotes meiosis II, and by transgene addition identified Zfy1 and Zfy2 as the genes responsible. Zfy2 was substantially more effective and proved to have a much more potent transactivation domain than Zfy1. We previously established that only Zfy2 is required for the robust apoptotic elimination of MI spermatocytes in response to a univalent X; the finding that both genes potentiate meiosis II led us to ask whether there was de novo Zfy1 and Zfy2 transcription in the interphase between meiosis I and meiosis II, and this proved to be the case. X-encoded Zfx was also expressed at this stage and Zfx over-expression also potentiated meiosis II. An interphase between the meiotic divisions is male-specific and we previously hypothesised that this allows meiosis II critical X and Y gene reactivation following sex chromosome silencing in meiotic prophase. The interphase transcription and meiosis II function of Zfx, Zfy1 and Zfy2 validate this hypothesis. PMID:24967676

Lignin biosynthesis perturbations affect secondary cell wall composition and saccharification yield in Arabidopsis thaliana

PubMed Central

2013-01-01

Background Second-generation biofuels are generally produced from the polysaccharides in the lignocellulosic plant biomass, mainly cellulose. However, because cellulose is embedded in a matrix of other polysaccharides and lignin, its hydrolysis into the fermentable glucose is hampered. The senesced inflorescence stems of a set of 20 Arabidopsis thaliana mutants in 10 different genes of the lignin biosynthetic pathway were analyzed for cell wall composition and saccharification yield. Saccharification models were built to elucidate which cell wall parameters played a role in cell wall recalcitrance. Results Although lignin is a key polymer providing the strength necessary for the plant’s ability to grow upward, a reduction in lignin content down to 64% of the wild-type level in Arabidopsis was tolerated without any obvious growth penalty. In contrast to common perception, we found that a reduction in lignin was not compensated for by an increase in cellulose, but rather by an increase in matrix polysaccharides. In most lignin mutants, the saccharification yield was improved by up to 88% cellulose conversion for the cinnamoyl-coenzyme A reductase1 mutants under pretreatment conditions, whereas the wild-type cellulose conversion only reached 18%. The saccharification models and Pearson correlation matrix revealed that the lignin content was the main factor determining the saccharification yield. However, also lignin composition, matrix polysaccharide content and composition, and, especially, the xylose, galactose, and arabinose contents influenced the saccharification yield. Strikingly, cellulose content did not significantly affect saccharification yield. Conclusions Although the lignin content had the main effect on saccharification, also other cell wall factors could be engineered to potentially increase the cell wall processability, such as the galactose content. Our results contribute to a better understanding of the effect of lignin perturbations on plant cell

Analysis of the trade-off between high crop yield and low yield instability at the global scale

NASA Astrophysics Data System (ADS)

Ben-Ari, Tamara; Makowski, David

2016-10-01

Yield dynamics of major crops species vary remarkably among continents. Worldwide distribution of cropland influences both the expected levels and the interannual variability of global yields. An expansion of cultivated land in the most productive areas could theoretically increase global production, but also increase global yield instability if the most productive regions are characterized by high interannual yield variability. In this letter, we use portfolio analysis to quantify the tradeoff between the expected values and the interannual variance of global yield. We compute optimal frontiers for four crop species i.e., maize, rice, soybean and wheat and show how the distribution of cropland among large world regions can be optimized to either increase expected global crop production or decrease its interannual variability. We also show that a preferential allocation of cropland in the most productive regions can increase global expected yield at the expense of yield stability. Theoretically, optimizing the distribution of a small fraction of total cultivated areas can help find a good compromise between low instability and high crop yields at the global scale.

Sensitivity of simulated maize crop yields to regional climate in the Southwestern United States

NASA Astrophysics Data System (ADS)

Kim, S.; Myoung, B.; Stack, D.; Kim, J.; Hatzopoulos, N.; Kafatos, M.

2013-12-01

The sensitivity of maize yield to the regional climate in the Southwestern United States (SW US) has been investigated by using a crop-yield simulation model (APSIM) in conjunction with meteorological forcings (daily minimum and maximum temperature, precipitation, and radiation) from the North American Regional Reanalysis (NARR) dataset. The primary focus of this study is to look at the effects of interannual variations of atmospheric components on the crop productivity in the SW US over the 21-year period (1991 to 2011). First of all, characteristics and performance of APSIM was examined by comparing simulated maize yields with observed yields from United States Department of Agriculture (USDA) and the leaf-area index (LAI) from MODIS satellite data. Comparisons of the simulated maize yield with the available observations show that the crop model can reasonably reproduce observed maize yields. Sensitivity tests were performed to assess the relative contribution of each climate driver to regional crop yield. Sensitivity experiments show that potential crop production responds nonlinearly to climate drivers and the yield sensitivity varied among geographical locations depending on their mean climates. Lastly, a detailed analysis of both the spatial and temporal variations of each climate driver in the regions where maize is actually grown in three states (CA, AZ, and NV) in the SW US was performed.

Climate Variability and Yields of Major Staple Food Crops in Northern Ghana

NASA Astrophysics Data System (ADS)

Amikuzuno, J.

2012-12-01

Climate variability, the short-term fluctuations in average weather conditions, and agriculture affect each other. Climate variability affects the agroecological and growing conditions of crops and livestock, and is recently believed to be the greatest impediment to the realisation of the first Millennium Development Goal of reducing poverty and food insecurity in arid and semi-arid regions of developing countries. Conversely, agriculture is a major contributor to climate variability and change by emitting greenhouse gases and reducing the agroecology's potential for carbon sequestration. What however, is the empirical evidence of this inter-dependence of climate variability and agriculture in Sub-Sahara Africa? In this paper, we provide some insight into the long run relationship between inter-annual variations in temperature and rainfall, and annual yields of the most important staple food crops in Northern Ghana. Applying pooled panel data of rainfall, temperature and yields of the selected crops from 1976 to 2010 to cointegration and Granger causality models, there is cogent evidence of cointegration between seasonal, total rainfall and crop yields; and causality from rainfall to crop yields in the Sudano-Guinea Savannah and Guinea Savannah zones of Northern Ghana. This suggests that inter-annual yields of the crops have been influenced by the total mounts of rainfall in the planting season. Temperature variability over the study period is however stationary, and is suspected to have minimal effect if any on crop yields. Overall, the results confirm the appropriateness of our attempt in modelling long-term relationships between the climate and crop yield variables.

Effect of Strong Acid Functional Groups on Electrode Rise Potential in Capacitive Mixing by Double Layer Expansion

DOE PAGES

Hatzell, Marta C.; Raju, Muralikrishna; Watson, Valerie J.; ...

2014-11-03

We report that the amount of salinity-gradient energy that can be obtained through capacitive mixing based on double layer expansion depends on the extent the electric double layer (EDL) is altered in a low salt concentration (LC) electrolyte (e.g., river water). We show that the electrode-rise potential, which is a measure of the EDL perturbation process, was significantly (P = 10 –5) correlated to the concentration of strong acid surface functional groups using five types of activated carbon. Electrodes with the lowest concentration of strong acids (0.05 mmol g –1) had a positive rise potential of 59 ± 4 mVmore » in the LC solution, whereas the carbon with the highest concentration (0.36 mmol g –1) had a negative rise potential (₋31 ± 5 mV). Chemical oxidation of a carbon (YP50) using nitric acid decreased the electrode rise potential from 46 ± 2 mV (unaltered) to ₋6 ± 0.5 mV (oxidized), producing a whole cell potential (53 ± 1.7 mV) that was 4.4 times larger than that obtained with identical electrode materials (from 12 ± 1 mV). Changes in the EDL were linked to the behavior of specific ions in a LC solution using molecular dynamics and metadynamics simulations. The EDL expanded in the LC solution when a carbon surface (pristine graphene) lacked strong acid functional groups, producing a positive-rise potential at the electrode. In contrast, the EDL was compressed for an oxidized surface (graphene oxide), producing a negative-rise electrode potential. In conclusion, these results established the linkage between rise potentials and specific surface functional groups (strong acids) and demonstrated on a molecular scale changes in the EDL using oxidized or pristine carbons.« less

Camelina Seed Yield and Fatty Acids as Influenced by Genotype and Environment

DOE PAGES

Obour, Augustine K.; Obeng, Eric; Mohammed, Yesuf A.; ...

2017-05-05

Camelina (Camelina sativa L. Crantz) is an alternative oilseed crop with potential for fallow replacement in dryland cereal-based crop production systems in the semiarid Great Plains. The interaction between genotype and environment was investigated on camelina seed yield, oil content, and fatty acid composition across two locations in the U.S. Great Plains. Treatments were three spring camelina genotypes (cultivars Blaine Creek, Pronghorn, and Shoshone), three growing seasons (2013, 2014, and 2015) and two locations (at Hays, KS, and Moccasin, MT). Our results showed camelina grown at Hays yielded 54% less than that at Moccasin. Blaine Creek yielded 17 and 42%more » more than Pronghorn and Shoshone at Hays but yields were not different among genotypes at Moccasin. Oil content ranged from 262 g kg -1 at Hays to 359 g kg -1 at Moccasin. The proportion of polyunsaturated fatty acids (PUFAs) ranged from 51% at Hays to 55% at Moccasin, whereas monounsaturated fatty acid (MUFA) and saturated fatty acid (SFA) contents were greater at Hays. The linolenic acid content ranged from 26% when Pronghorn was planted at Hays to 35% when planted at Moccasin. In general, the variations in seed yield and fatty acid profile corresponded well with growing season precipitation and temperatures at each environment.« less

Camelina Seed Yield and Fatty Acids as Influenced by Genotype and Environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Obour, Augustine K.; Obeng, Eric; Mohammed, Yesuf A.

Camelina (Camelina sativa L. Crantz) is an alternative oilseed crop with potential for fallow replacement in dryland cereal-based crop production systems in the semiarid Great Plains. The interaction between genotype and environment was investigated on camelina seed yield, oil content, and fatty acid composition across two locations in the U.S. Great Plains. Treatments were three spring camelina genotypes (cultivars Blaine Creek, Pronghorn, and Shoshone), three growing seasons (2013, 2014, and 2015) and two locations (at Hays, KS, and Moccasin, MT). Our results showed camelina grown at Hays yielded 54% less than that at Moccasin. Blaine Creek yielded 17 and 42%more » more than Pronghorn and Shoshone at Hays but yields were not different among genotypes at Moccasin. Oil content ranged from 262 g kg -1 at Hays to 359 g kg -1 at Moccasin. The proportion of polyunsaturated fatty acids (PUFAs) ranged from 51% at Hays to 55% at Moccasin, whereas monounsaturated fatty acid (MUFA) and saturated fatty acid (SFA) contents were greater at Hays. The linolenic acid content ranged from 26% when Pronghorn was planted at Hays to 35% when planted at Moccasin. In general, the variations in seed yield and fatty acid profile corresponded well with growing season precipitation and temperatures at each environment.« less

End product yields from the extraruminal fermentation of various polysaccharide, protein and nucleic acid components of biofuels feedstocks.

PubMed

Weimer, Paul J

2011-02-01

"Extraruminal" fermentations employing in vitro incubation of mixed ruminal bacterial consortia, are capable of converting a complex array of biomass materials to mixtures of volatile fatty acids (VFA), methane, and carbon dioxide. Most of the potential energy in the biomass feedstock is retained in the VFA products, which are potential reactants for electrochemical conversion to hydrocarbon fuels. Quantitative data on VFA yields and proportions from biomass components are necessary for determining industrial feasibility, but such measurements have not been systematically reported. VFA yields and proportions were determined for a variety of carbohydrates, proteins and nucleic acids. Carbohydrates yielded primarily acetic and propionic acids, while proteins also yielded a more favorable product mix (longer average chain length and branched chain VFAs). Addition of certain co-substrates (e.g., glycerol) favorably improved the VFA product mix. The results have implications for hydrocarbon fuel generation from biomass materials by hybrid fermentation/chemical processes. Published by Elsevier Ltd.

Bottomonium suppression using a lattice QCD vetted potential

NASA Astrophysics Data System (ADS)

Krouppa, Brandon; Rothkopf, Alexander; Strickland, Michael

2018-01-01

We estimate bottomonium yields in relativistic heavy-ion collisions using a lattice QCD vetted, complex-valued, heavy-quark potential embedded in a realistic, hydrodynamically evolving medium background. We find that the lattice-vetted functional form and temperature dependence of the proper heavy-quark potential dramatically reduces the dependence of the yields on parameters other than the temperature evolution, strengthening the picture of bottomonium as QGP thermometer. Our results also show improved agreement between computed yields and experimental data produced in RHIC 200 GeV /nucleon collisions. For LHC 2.76 TeV /nucleon collisions, the excited states, whose suppression has been used as a vital sign for quark-gluon-plasma production in a heavy-ion collision, are reproduced better than previous perturbatively-motivated potential models; however, at the highest LHC energies our estimates for bottomonium suppression begin to underestimate the data. Possible paths to remedy this situation are discussed.

Increased Night Temperature Negatively Affects Grain Yield, Biomass and Grain Number in Chilean Quinoa

PubMed Central

Lesjak, Jurka; Calderini, Daniel F.

2017-01-01

Quinoa high nutritive value increases interest worldwide, especially as a crop that could potentially feature in different cropping systems, however, climate change, particularly rising temperatures, challenges this and other crop species. Currently, only limited knowledge exists regarding the grain yield and other key traits response to higher temperatures of this crop, especially to increased night temperatures. In this context, the main objective of this study was to evaluate the effect of increased night temperature on quinoa yield, grain number, individual grain weight and processes involved in crop growth under the environmental conditions (control treatment) and night thermal increase at two phases: flowering (T1) and grain filling (T2) in southern Chile. A commercial genotype, Regalona, and a quinoa accession (Cod. BO5, N°191, grain bank from Semillas Baer, hereby referred to as Accession) were used, due to their adaptability to Southern Chilean conditions and contrasting grain yield potential, grain weight and size of plants. Temperature was increased ≈4°C above the ambient from 8 pm until 9 am the next morning. Control treatments reached a high grain yield (600 and 397 g m-2, i.e., Regalona and Accession). Temperature increase reduced grain yield by 31% under T1 treatment and 12% when under T2 in Regalona and 23 and 26% in Accession, respectively. Aboveground biomass was negatively affected by the thermal treatments and a positive linear association was found between grain yield and aboveground biomass across treatments. By contrast, the harvest index was unaffected either by genotype, or by thermal treatments. Grain number was significantly affected between treatments and this key trait was linearly associated with grain yield. On the other hand, grain weight showed a narrow range of variation across treatments. Additionally, leaf area index was not affected, but significant differences were found in SPAD values at the end of T1 treatment, compared

Selected wild strains of Agaricus bisporus produce high yields of mushrooms at 25°C.

PubMed

Navarro, Pilar; Savoie, Jean-Michel

2015-01-01

To cultivate the button mushroom Agaricus bisporus in warm countries or during summer in temperate countries, while saving energy, is a challenge that could be addressed by using the biological diversity of the species. The objective was to evaluate the yield potential of eight wild strains previously selected in small scale experiments for their ability to produce mature fruiting bodies at 25°C and above. Culture units of 8 kg of compost were used. The yield expressed as weight or number per surface unit and earliness of fruiting were recorded during cultivation in climatic rooms at 17, 25 or 30°C. Only strains of A. bisporus var. burnettii were able to fruit at 30°C. At 25°C they produced the highest yields (27 kg m(-2)) and had best earliness. The yields at 25°C for the strains of A. bisporus var. bisporus ranged from 12 to 16 kg m(-2). The yield ratios 25°C/17°C ranged from 0.8 to 1.2. The variety burnettii originated in the Sonoran Desert in California showed adaptation for quickly producing fruiting bodies at high temperature when humidity conditions were favorable. Strains of the variety bisporus showed interesting potentials for their ability to produce mature fruiting bodies at higher temperature than present cultivars and might be used in breeding programs. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Added-values of high spatiotemporal remote sensing data in crop yield estimation

NASA Astrophysics Data System (ADS)

Gao, F.; Anderson, M. C.

2017-12-01

Timely and accurate estimation of crop yield before harvest is critical for food market and administrative planning. Remote sensing derived parameters have been used for estimating crop yield by using either empirical or crop growth models. The uses of remote sensing vegetation index (VI) in crop yield modeling have been typically evaluated at regional and country scales using coarse spatial resolution (a few hundred to kilo-meters) data or assessed over a small region at field level using moderate resolution spatial resolution data (10-100m). Both data sources have shown great potential in capturing spatial and temporal variability in crop yield. However, the added value of data with both high spatial and temporal resolution data has not been evaluated due to the lack of such data source with routine, global coverage. In recent years, more moderate resolution data have become freely available and data fusion approaches that combine data acquired from different spatial and temporal resolutions have been developed. These make the monitoring crop condition and estimating crop yield at field scale become possible. Here we investigate the added value of the high spatial and temporal VI for describing variability of crop yield. The explanatory ability of crop yield based on high spatial and temporal resolution remote sensing data was evaluated in a rain-fed agricultural area in the U.S. Corn Belt. Results show that the fused Landsat-MODIS (high spatial and temporal) VI explains yield variability better than single data source (Landsat or MODIS alone), with EVI2 performing slightly better than NDVI. The maximum VI describes yield variability better than cumulative VI. Even though VI is effective in explaining yield variability within season, the inter-annual variability is more complex and need additional information (e.g. weather, water use and management). Our findings augment the importance of high spatiotemporal remote sensing data and supports new moderate

Age Differences in the Reception of New Scientific Theories: The Case of Plate Tectonics Theory.

ERIC Educational Resources Information Center

Messeri, Peter

1988-01-01

Reviews various evidences on the relationship between age and the reception of major innovations in science. Examines the possibility that age patterning of reception may vary over time. Reports the potential importance of age on the reception of ideas while rejecting the presumption that advanced age leads to increased resistance. (YP)

Determination of Dacarbazine Φ-Order Photokinetics, Quantum Yields, and Potential for Actinometry.

PubMed

Maafi, Mounir; Lee, Lok-Yan

2015-10-01

The characterization of drugs' photodegradation kinetics is more accurately achieved by means of the recently developed Φ-order kinetics than by the zero-, first-, and/or second-order classical treatments. The photodegradation of anti-cancer dacarbazine (DBZ) in ethanol has been investigated and found to obey Φ-order kinetics when subjected to continuous and monochromatic irradiation of various wavelengths. Its photochemical efficiency was proven to be wavelength dependent in the 220-350 nm range, undergoing a 50-fold increase. Albeit this variation was well defined by a sigmoid pattern, the overall photoreactivity of DBZ was proven to depend also on the contributions of reactants and experimental attributes. The usefulness of DBZ to serve as a drug-actinometer has been investigated using the mathematical framework of Φ-order kinetics. It has been shown that DBZ in ethanol can represent a good candidate for reliable actinometry in the range 270-350 nm. A detailed and easy-to-implement procedure has been proposed for DBZ actinometry. This procedure could advantageously be implemented prior to the determination of the photodegradation quantum yields. This approach might be found useful for the development of many drug actinometers as alternatives to quinine hydrochloride. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

Discrete Electronic Bands in Semiconductors and Insulators: Potential High-Light-Yield Scintillators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Hongliang; Du, Mao-Hua

Bulk semiconductors and insulators typically have continuous valence and conduction bands. In this paper, we show that valence and conduction bands of a multinary semiconductor or insulator can be split to narrow discrete bands separated by large energy gaps. This unique electronic structure is demonstrated by first-principles calculations in several quaternary elpasolite compounds, i.e., Cs 2NaInBr 6, Cs 2NaBiCl 6, and Tl 2NaBiCl 6. The narrow discrete band structure in these quaternary elpasolites is due to the large electronegativity difference among cations and the large nearest-neighbor distances in cation sublattices. We further use Cs 2NaInBr 6 as an example tomore » show that the narrow bands can stabilize self-trapped and dopant-bound excitons (in which both the electron and the hole are strongly localized in static positions on adjacent sites) and promote strong exciton emission at room temperature. The discrete band structure should further suppress thermalization of hot carriers and may lead to enhanced impact ionization, which is usually considered inefficient in bulk semiconductors and insulators. Finally, these characteristics can enable efficient room-temperature light emission in low-gap scintillators and may overcome the light-yield bottleneck in current scintillator research.« less

Discrete Electronic Bands in Semiconductors and Insulators: Potential High-Light-Yield Scintillators

DOE PAGES

Shi, Hongliang; Du, Mao-Hua

2015-05-12

Bulk semiconductors and insulators typically have continuous valence and conduction bands. In this paper, we show that valence and conduction bands of a multinary semiconductor or insulator can be split to narrow discrete bands separated by large energy gaps. This unique electronic structure is demonstrated by first-principles calculations in several quaternary elpasolite compounds, i.e., Cs 2NaInBr 6, Cs 2NaBiCl 6, and Tl 2NaBiCl 6. The narrow discrete band structure in these quaternary elpasolites is due to the large electronegativity difference among cations and the large nearest-neighbor distances in cation sublattices. We further use Cs 2NaInBr 6 as an example tomore » show that the narrow bands can stabilize self-trapped and dopant-bound excitons (in which both the electron and the hole are strongly localized in static positions on adjacent sites) and promote strong exciton emission at room temperature. The discrete band structure should further suppress thermalization of hot carriers and may lead to enhanced impact ionization, which is usually considered inefficient in bulk semiconductors and insulators. Finally, these characteristics can enable efficient room-temperature light emission in low-gap scintillators and may overcome the light-yield bottleneck in current scintillator research.« less

Altitude-Wind-Tunnel Investigation of Performance of Several Propellers on YP-47M Airplane at High Blade Loadings. 6; Hamilton Standard 6507A-2 Four- and Three-Blade Propellers

NASA Technical Reports Server (NTRS)

Saari, Martin J.; Sorin, Solomon M.

1946-01-01

An altitude-wind-tunnel investigation has been made to determine the performance of Hamilton Standard 6507A-2 four-blade and three-blade propellers on a YP-47M airplane at high blade loadings and high engine powers. Characteristics of the four-blase propeller were obtained for a range of power coefficients from 0.10 to 1.00 at free-stream Mach numbers of 0.20, 0.30, 0.40. Characteristics of the three-blade propeller were obtained for a range of power coefficients from 0.30 to 1.00 at a free-stream Mach number of 0.40. Results of the force measurements indicate primarily the trend of propeller efficiency for changes in power coefficient or advance-diameter ratio because no corrections for the effects of tunnel-wall constriction on the installation were applied. Slipstream surveys are presented to illustrate blade thrust load distribution for certain operating conditions. Within the range of advance-diameter ratios investigated at each free-stream Mach number, the efficiency of the four-blade propeller decreased as the power coefficient was increased from 0.10 to 1.00. For the three-blade propeller, nearly constant maximum efficiencies were obtained for power coefficients from 0.32 to 0.63 at advance-diameter ratios between 1.90 and 3.00. In general, for conditions below the stall and critical tip Mach number, the maximum thrust load shifted from the inboard sections toward the tip sections as the power coefficient was increased or as the advance-diameter ratio was decreased. For conditions beyond the stall or critical tip Mach number, losses in thrust occurred on the outboard blade sections owing to flow break-down; the thrust load increased slightly on the inboard sections.

Yield and ultrasonic modulus of elasticity of red maple veneer

Treesearch

Robert J. Ross; Steven Verhey; John R. Erickson; John W. Forsman; Brian K. Brashaw; Crystal L. Pilon; Xiping Wang

2004-01-01

The purpose of the study was to assess the potential for using red maple sawlogs to manufacture laminated veneer lumber (LVL). The primary objective was to determine the yield of ultrasonically graded veneer from red maple logs. A sample of 48 logs was obtained from six Eastern and Lake States in the United States. The logs were visually graded and shipped to a plywood...

Fission yield measurements at IGISOL

NASA Astrophysics Data System (ADS)

Lantz, M.; Al-Adili, A.; Gorelov, D.; Jokinen, A.; Kolhinen, V. S.; Mattera, A.; Moore, I.; Penttilä, H.; Pomp, S.; Prokofiev, A. V.; Rakopoulos, V.; Rinta-Antila, S.; Simutkin, V.; Solders, A.

2016-06-01

The fission product yields are an important characteristic of the fission process. In fundamental physics, knowledge of the yield distributions is needed to better understand the fission process. For nuclear energy applications good knowledge of neutroninduced fission-product yields is important for the safe and efficient operation of nuclear power plants. With the Ion Guide Isotope Separator On-Line (IGISOL) technique, products of nuclear reactions are stopped in a buffer gas and then extracted and separated by mass. Thanks to the high resolving power of the JYFLTRAP Penning trap, at University of Jyväskylä, fission products can be isobarically separated, making it possible to measure relative independent fission yields. In some cases it is even possible to resolve isomeric states from the ground state, permitting measurements of isomeric yield ratios. So far the reactions U(p,f) and Th(p,f) have been studied using the IGISOL-JYFLTRAP facility. Recently, a neutron converter target has been developed utilizing the Be(p,xn) reaction. We here present the IGISOL-technique for fission yield measurements and some of the results from the measurements on proton induced fission. We also present the development of the neutron converter target, the characterization of the neutron field and the first tests with neutron-induced fission.

Yield model development project implementation plan

NASA Technical Reports Server (NTRS)

Ambroziak, R. A.

1982-01-01

Tasks remaining to be completed are summarized for the following major project elements: (1) evaluation of crop yield models; (2) crop yield model research and development; (3) data acquisition processing, and storage; (4) related yield research: defining spectral and/or remote sensing data requirements; developing input for driving and testing crop growth/yield models; real time testing of wheat plant process models) and (5) project management and support.

Hauser-Feshbach fission fragment de-excitation with calculated macroscopic-microscopic mass yields

NASA Astrophysics Data System (ADS)

Jaffke, Patrick; Möller, Peter; Talou, Patrick; Sierk, Arnold J.

2018-03-01

The Hauser-Feshbach statistical model is applied to the de-excitation of primary fission fragments using input mass yields calculated with macroscopic-microscopic models of the potential energy surface. We test the sensitivity of the prompt fission observables to the input mass yields for two important reactions, 235U(nth,f ) and 239Pu(nth,f ) , for which good experimental data exist. General traits of the mass yields, such as the location of the peaks and their widths, can impact both the prompt neutron and γ -ray multiplicities, as well as their spectra. Specifically, we use several mass yields to determine a linear correlation between the calculated prompt neutron multiplicity ν ¯ and the average heavy-fragment mass 〈Ah〉 of the input mass yields ∂ ν ¯/∂ 〈Ah〉 =±0.1 (n /f ) /u . The mass peak width influences the correlation between the total kinetic energy of the fission fragments and the total number of prompt neutrons emitted, ν¯T(TKE ) . Typical biases on prompt particle observables from using calculated mass yields instead of experimental ones are δ ν ¯=4 % for the average prompt neutron multiplicity, δ M ¯γ=1 % for the average prompt γ -ray multiplicity, δ ɛ¯nLAB=1 % for the average outgoing neutron energy, δ ɛ¯γ=1 % for the average γ -ray energy, and δ 〈TKE 〉=0.4 % for the average total kinetic energy of the fission fragments.

Linkages among climate change, crop yields and Mexico–US cross-border migration

PubMed Central

Feng, Shuaizhang; Krueger, Alan B.; Oppenheimer, Michael

2010-01-01

Climate change is expected to cause mass human migration, including immigration across international borders. This study quantitatively examines the linkages among variations in climate, agricultural yields, and people's migration responses by using an instrumental variables approach. Our method allows us to identify the relationship between crop yields and migration without explicitly controlling for all other confounding factors. Using state-level data from Mexico, we find a significant effect of climate-driven changes in crop yields on the rate of emigration to the United States. The estimated semielasticity of emigration with respect to crop yields is approximately −0.2, i.e., a 10% reduction in crop yields would lead an additional 2% of the population to emigrate. We then use the estimated semielasticity to explore the potential magnitude of future emigration. Depending on the warming scenarios used and adaptation levels assumed, with other factors held constant, by approximately the year 2080, climate change is estimated to induce 1.4 to 6.7 million adult Mexicans (or 2% to 10% of the current population aged 15–65 y) to emigrate as a result of declines in agricultural productivity alone. Although the results cannot be mechanically extrapolated to other areas and time periods, our findings are significant from a global perspective given that many regions, especially developing countries, are expected to experience significant declines in agricultural yields as a result of projected warming. PMID:20660749

Determining the Critical Dose Threshold of Electron-Induced Electron Yield for Minimally Charged Highly Insulating Materials

NASA Astrophysics Data System (ADS)

Hoffmann, Ryan; Dennison, J. R.; Abbott, Jonathan

2006-03-01

When incident energetic electrons interact with a material, they excite electrons within the material to escape energies. The electron emission is quantified as the ratio of emitted electrons to incident particle flux, termed electron yield. Measuring the electron yield of insulators is difficult due to dynamic surface charge accumulation which directly affects landing energies and the potential barrier that emitted electrons must overcome. Our recent measurements of highly insulating materials have demonstrated significant changes in total yield curves and yield decay curves for very small electron doses equivalent to a trapped charge density of <10^10 electrons /cm^3. The Chung-Everhart theory provides a basic model for the behavior of the electron emission spectra which we relate to yield decay curves as charge is allowed to accumulate. Yield measurements as a function of dose for polyimide (Kapton^TM) and microcrystalline SiO2 will be presented. We use our data and model to address the question of whether there is a minimal dose threshold at which the accumulated charge no longer affects the yield.

Yield estimation of corn based on multitemporal LANDSAT-TM data as input for an agrometeorological model

NASA Astrophysics Data System (ADS)

Bach, Heike

1998-07-01

In order to test remote sensing data with advanced yield formation models for accuracy and timeliness of yield estimation of corn, a project was conducted for the State Ministry for Rural Environment, Food, and Forestry of Baden-Württemberg (Germany). This project was carried out during the course of the `Special Yield Estimation', a regular procedure conducted for the European Union, to more accurately estimate agricultural yield. The methodology employed uses field-based plant parameter estimation from atmospherically corrected multitemporal/multispectral LANDSAT-TM data. An agrometeorological plant-production-model is used for yield prediction. Based solely on four LANDSAT-derived estimates (between May and August) and daily meteorological data, the grain yield of corn fields was determined for 1995. The modelled yields were compared with results gathered independently within the Special Yield Estimation for 23 test fields in the upper Rhine valley. The agreement between LANDSAT-based estimates (six weeks before harvest) and Special Yield Estimation (at harvest) shows a relative error of 2.3%. The comparison of the results for single fields shows that six weeks before harvest, the grain yield of corn was estimated with a mean relative accuracy of 13% using satellite information. The presented methodology can be transferred to other crops and geographical regions. For future applications hyperspectral sensors show great potential to further enhance the results for yield prediction with remote sensing.

Flood-tolerant rice reduces yield variability and raises expected yield, differentially benefitting socially disadvantaged groups

PubMed Central

Dar, Manzoor H.; de Janvry, Alain; Emerick, Kyle; Raitzer, David; Sadoulet, Elisabeth

2013-01-01

Approximately 30% of the cultivated rice area in India is prone to crop damage from prolonged flooding. We use a randomized field experiment in 128 villages of Orissa India to show that Swarna-Sub1, a recently released submergence-tolerant rice variety, has significant positive impacts on rice yield when fields are submerged for 7 to 14 days with no yield penalty without flooding. We estimate that Swarna-Sub1 offers an approximate 45% increase in yields over the current popular variety when fields are submerged for 10 days. We show additionally that low-lying areas prone to flooding tend to be more heavily occupied by people belonging to lower caste social groups. Thus, a policy relevant implication of our findings is that flood-tolerant rice can deliver both efficiency gains, through reduced yield variability and higher expected yield, and equity gains in disproportionately benefiting the most marginal group of farmers. PMID:24263095

The Value Versus Volume Yield Problem for Live-Sawn Hardwood Sawlogs

Treesearch

Philip H. Steele; Francis G. Wagner; Lalit Kumar; Philip A. Araman

1993-01-01

The potential conflict between value and volume maximization in sawing hardwood sawlogs by the live sawing method was analyzed. Twenty-four digitally described red oak sawlogs were sawn at the log orientation of highest value yield. Five opening face sawlines were iteratively placed in the sawlog a 1/4-inch intervals and lumber grades, volumes, and values from...

Enhanced efficiency fertilizer’s effect on cotton yield and greenhouse gas emissions

USDA-ARS?s Scientific Manuscript database

Interest in the use of enhanced-efficiency nitrogen fertilizer (EENFs) sources has increased in recent years due to the potential of these new EENF sources to increase crop yield, while at the same time decreasing N loss from agricultural fields. Nitrogen is the most essential nutrient needed to op...

Asymmetric Yield Function Based on the Stress Invariants for Pressure Sensitive Metals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeong Wahn Yoon; Yanshan Lou; Jong Hun Yoon

A general asymmetric yield function is proposed with dependence on the stress invariants for pressure sensitive metals. The pressure sensitivity of the proposed yield function is consistent with the experimental result of Spitzig and Richmond (1984) for steel and aluminum alloys while the asymmetry of the third invariant is preserved to model strength differential (SD) effect of pressure insensitive materials. The proposed yield function is transformed in the space of the stress triaxaility, the von Mises stress and the normalized invariant to theoretically investigate the possible reason of the SD effect. The proposed plasticity model is further extended to characterizemore » the anisotropic behavior of metals both in tension and compression. The extension of the yield function is realized by introducing two distinct fourth-order linear transformation tensors of the stress tensor for the second and third invariants, respectively. The extended yield function reasonably models the evolution of yield surfaces for a zirconium clock-rolled plate during in-plane and through-thickness compression reported by Plunkett et al. (2007). The extended yield function is also applied to describe the orthotropic behavior of a face-centered cubic metal of AA 2008-T4 and two hexagonal close-packed metals of high-purity-titanium and AZ31 magnesium alloy. The orthotropic behavior predicted by the generalized model is compared with experimental results of these metals. The comparison validates that the proposed yield function provides sufficient predictability on SD effect and anisotropic behavior both in tension and compression. When it is necessary to consider r-value anisotropy, the proposed function is efficient to be used with nonassociated flow plasticity by introducing a separate plastic potential for the consideration of r-values as shown in Stoughton & Yoon (2004, 2009).« less

Growth, Yield and Fruit Quality of Grapevines under Organic and Biodynamic Management

PubMed Central

Döring, Johanna; Frisch, Matthias; Tittmann, Susanne; Stoll, Manfred; Kauer, Randolf

2015-01-01

The main objective of this study was to determine growth, yield and fruit quality of grapevines under organic and biodynamic management in relation to integrated viticultural practices. Furthermore, the mechanisms for the observed changes in growth, yield and fruit quality were investigated by determining nutrient status, physiological performance of the plants and disease incidence on bunches in three consecutive growing seasons. A field trial (Vitis vinifera L. cv. Riesling) was set up at Hochschule Geisenheim University, Germany. The integrated treatment was managed according to the code of good practice. Organic and biodynamic plots were managed according to Regulation (EC) No 834/2007 and Regulation (EC) No 889/2008 and according to ECOVIN- and Demeter-Standards, respectively. The growth and yield of the grapevines differed strongly among the different management systems, whereas fruit quality was not affected by the management system. The organic and the biodynamic treatments showed significantly lower growth and yield in comparison to the integrated treatment. The physiological performance was significantly lower in the organic and the biodynamic systems, which may account for differences in growth and cluster weight and might therefore induce lower yields of the respective treatments. Soil management and fertilization strategy could be responsible factors for these changes. Yields of the organic and the biodynamic treatments partially decreased due to higher disease incidence of downy mildew. The organic and the biodynamic plant protection strategies that exclude the use of synthetic fungicides are likely to induce higher disease incidence and might partially account for differences in the nutrient status of vines under organic and biodynamic management. Use of the biodynamic preparations had little influence on vine growth and yield. Due to the investigation of important parameters that induce changes especially in growth and yield of grapevines under

Maximum sustainable yield and species extinction in a prey-predator system: some new results.

PubMed

Ghosh, Bapan; Kar, T K

2013-06-01

Though the maximum sustainable yield (MSY) approach has been legally adopted for the management of world fisheries, it does not provide any guarantee against from species extinction in multispecies communities. In the present article, we describe the appropriateness of the MSY policy in a Holling-Tanner prey-predator system with different types of functional responses. It is observed that for both type I and type II functional responses, harvesting of either prey or predator species at the MSY level is a sustainable fishing policy. In the case of combined harvesting, both the species coexist at the maximum sustainable total yield (MSTY) level if the biotic potential of the prey species is greater than a threshold value. Further, increase of the biotic potential beyond the threshold value affects the persistence of the system.

Diverse regulatory factors associate with flowering time and yield responses in winter-type Brassica napus.

PubMed

Schiessl, Sarah; Iniguez-Luy, Federico; Qian, Wei; Snowdon, Rod J

2015-09-29

Flowering time, plant height and seed yield are strongly influenced by climatic and day-length adaptation in crop plants. To investigate these traits under highly diverse field conditions in the important oilseed crop Brassica napus, we performed a genome-wide association study using data from diverse agroecological environments spanning three continents. A total of 158 European winter-type B.napus inbred lines were genotyped with 21,623 unique, single-locus single-nucleotide polymorphism (SNP) markers using the Brassica 60 K-SNP Illumina® Infinium consortium array. Phenotypic associations were calculated in the panel over the years 2010-2012 for flowering time, plant height and seed yield in 5 highly diverse locations in Germany, China and Chile, adding up to 11 diverse environments in total. We identified 101 genome regions associating with the onset of flowering, 69 with plant height, 36 with seed yield and 68 cross-trait regions with potential adaptive value. Within these regions, B.napus orthologs for a number of candidate adaptation genes were detected, including central circadian clock components like CIRCADIAN CLOCK- ASSOCIATED 1 (Bna.CCA1) and the important flowering-time regulators FLOWERING LOCUS T (Bna.FT) and FRUITFUL (Bna.FUL). Gene ontology (GO) enrichment analysis of candidate regions suggested that selection of genes involved in post-transcriptional and epigenetic regulation of flowering time may play a potential role in adaptation of B. napus to highly divergent environments. The classical flowering time regulators Bna.FLC and Bna.CO were not found among the candidate regions, although both show functional variation. Allelic effects were additive for plant height and yield, but not for flowering time. The scarcity of positive minor alleles for yield in this breeding pool points to a lack of diversity for adaptation that could restrict yield gain in the face of environmental change. Our study provides a valuable framework to further improve the

Collagen type I from bovine bone. Effect of animal age, bone anatomy and drying methodology on extraction yield, self-assembly, thermal behaviour and electrokinetic potential.

PubMed

Ferraro, Vincenza; Gaillard-Martinie, Brigitte; Sayd, Thierry; Chambon, Christophe; Anton, Marc; Santé-Lhoutellier, Véronique

2017-04-01

Natural collagen is easily available from animal tissues such as bones. Main limitations reported in the use of natural collagen are heterogeneity and loss of integrity during recovery. However, its natural complexity, functionality and bioactivity still remain to be achieved through synthetic and recombinant ways. Variability of physicochemical properties of collagen extracted from bovine bone by acetic acid was then investigated taking into account endogenous and exogenous factors. Endogenous: bovine's bones age (4 and 7 years) and anatomy (femur and tibia); exogenous: thermal treatments (spray-drying and lyophilisation). Scanning electron microscopy, spectroscopy (EDS, FTIR, UV/Vis and CD), differential scanning calorimetry (DSC), centesimal composition, mass spectrometry, amino acids and zeta-potential analysis were used for the purpose. Age correlated negatively with yield of recovery and positively with minerals and proteoglycans content. Comparing the anatomy, higher yields were found for tibias, and higher stability of tibias collagen in solution was noticed. Whatever the age and the anatomy, collagens were able to renature and to self-assemble into tri-dimensional structures. Nonetheless thermal stability and kinetics of renaturation were different. Variability of natural collagen with bone age and anatomy, and drying methodology, may be a crucial advantage to conceive tailor-made applications in either the biological or technical sector. Copyright © 2016 Elsevier B.V. All rights reserved.

A mutli-omic systems approach to elucidating Yersinia virulence mechanisms

PubMed Central

Ansong, Charles; Schrimpe-Rutledge, Alexandra C.; Mitchell, Hugh; Chauhan, Sadhana; Jones, Marcus B.; Kim, Young-Mo; McAteer, Kathleen; Deatherage Kaiser, Brooke L.; Dubois, Jennifer L.; Brewer, Heather M.; Frank, Bryan C.; McDermott, Jason E.; Metz, Thomas O.; Peterson, Scott N.; Smith, Richard D.; Motin, Vladimir L.; Adkins, Joshua N.

2012-01-01

The underlying mechanisms that lead to dramatic differences between closely related pathogens are not always readily apparent. For example, the genomes of Yersinia pestis (YP) the causative agent of plague with a high mortality rate and Yersinia pseudotuberculosis (YPT) an enteric pathogen with a modest mortality rate are highly similar with some species specific differences; however the molecular causes of their distinct clinical outcomes remain poorly understood. In this study, a temporal multi-omic analysis of YP and YPT at physiologically relevant temperatures was performed to gain insights into how an acute and highly lethal bacterial pathogen, YP, differs from its less virulent progenitor, YPT. This analysis revealed higher gene and protein expression levels of conserved major virulence factors in YP relative to YPT, including the Yop virulon and the pH6 antigen. This suggests that adaptation in the regulatory architecture, in addition to the presence of unique genetic material, may contribute to the increased pathogenenicity of YP relative to YPT. Additionally, global transcriptome and proteome responses of YP and YPT revealed conserved post-transcriptional control of metabolism and the translational machinery including the modulation of glutamate levels in Yersiniae. Finally, the omics data was coupled with a computational network analysis, allowing an efficient prediction of novel Yersinia virulence factors based on gene and protein expression patterns. PMID:23147219

Anaerobic co-digestion of the organic fraction of municipal solid waste with FOG waste from a sewage treatment plant: Recovering a wasted methane potential and enhancing the biogas yield

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin-Gonzalez, L., E-mail: lucia.martin@uab.ca; Colturato, L.F.; Font, X.

2010-10-15

Anaerobic digestion is applied widely to treat the source collected organic fraction of municipal solid wastes (SC-OFMSW). Lipid-rich wastes are a valuable substrate for anaerobic digestion due to their high theoretical methane potential. Nevertheless, although fat, oil and grease waste from sewage treatment plants (STP-FOGW) are commonly disposed of in landfill, European legislation is aimed at encouraging more effective forms of treatment. Co-digestion of the above wastes may enhance valorisation of STP-FOGW and lead to a higher biogas yield throughout the anaerobic digestion process. In the present study, STP-FOGW was evaluated as a co-substrate in wet anaerobic digestion of SC-OFMSWmore » under mesophilic conditions (37 {sup o}C). Batch experiments carried out at different co-digestion ratios showed an improvement in methane production related to STP-FOGW addition. A 1:7 (VS/VS) STP-FOGW:SC-OFMSW feed ratio was selected for use in performing further lab-scale studies in a 5 L continuous reactor. Biogas yield increased from 0.38 {+-} 0.02 L g VS{sub feed}{sup -1} to 0.55 {+-} 0.05 L g VS{sub feed}{sup -1} as a result of adding STP-FOGW to reactor feed. Both VS reduction values and biogas methane content were maintained and inhibition produced by long chain fatty acid (LCFA) accumulation was not observed. Recovery of a currently wasted methane potential from STP-FOGW was achieved in a co-digestion process with SC-OFMSW.« less

Anaerobic co-digestion of the organic fraction of municipal solid waste with FOG waste from a sewage treatment plant: recovering a wasted methane potential and enhancing the biogas yield.

PubMed

Martín-González, L; Colturato, L F; Font, X; Vicent, T

2010-10-01

Anaerobic digestion is applied widely to treat the source collected organic fraction of municipal solid wastes (SC-OFMSW). Lipid-rich wastes are a valuable substrate for anaerobic digestion due to their high theoretical methane potential. Nevertheless, although fat, oil and grease waste from sewage treatment plants (STP-FOGW) are commonly disposed of in landfill, European legislation is aimed at encouraging more effective forms of treatment. Co-digestion of the above wastes may enhance valorisation of STP-FOGW and lead to a higher biogas yield throughout the anaerobic digestion process. In the present study, STP-FOGW was evaluated as a co-substrate in wet anaerobic digestion of SC-OFMSW under mesophilic conditions (37 degrees C). Batch experiments carried out at different co-digestion ratios showed an improvement in methane production related to STP-FOGW addition. A 1:7 (VS/VS) STP-FOGW:SC-OFMSW feed ratio was selected for use in performing further lab-scale studies in a 5L continuous reactor. Biogas yield increased from 0.38+/-0.02 L g VS(feed)(-1) to 0.55+/-0.05 L g VS(feed)(-1) as a result of adding STP-FOGW to reactor feed. Both VS reduction values and biogas methane content were maintained and inhibition produced by long chain fatty acid (LCFA) accumulation was not observed. Recovery of a currently wasted methane potential from STP-FOGW was achieved in a co-digestion process with SC-OFMSW. (c) 2010 Elsevier Ltd. All rights reserved.

Waterlogging effects on growth and yield components in late-planted soybean.

PubMed

Linkemer, G; Board, J E; Musgrave, M E

1998-01-01

A major agronomic problem in the southeastern USA is low yield of late-planted soybean [Glycine max (L.) Merr.]. This problem is aggravated by the adverse effect of waterlogging on crop growth. Our objectives were to identify soybean growth stages sensitive to waterlogging; identify yield components and physiological parameters explaining yield losses induced by waterlogging; and determine the extent of yield losses induced by waterlogging under natural field conditions. Greenhouse and field studies were conducted during 1993 and 1994 near Baton Rouge, LA, (30 degrees N Lat) on a Commerce silt loam. Waterlogging tolerance was assessed in cultivar Centennial (Maturity Group VI) at three vegetative and five reproductive growth stages by maintaining the water level at the soil surface in a greenhouse study. Using the same cultivar, we evaluated the effect of drainage in the field for late-planted soybean. Rain episodes determined the timing of waterlogging; redox potential and oxygen concentration of the soil were used to quantify the intensity of waterlogging stress. Results of the greenhouse study indicated that the early vegetative period (V2) and the early reproductive stages (R1, R3, and R5) were most sensitive to waterlogging. Three to 5 cm of rain per day falling on poorly drained soil was sufficient to reduce crop growth rate, resulting in a yield decline from 2453 to 1550 kg ha-1. Yield loss in both field and greenhouse studies was induced primarily by decreased pod production resulting from fewer pods per reproductive node. In conclusion, waterlogging was determined to be an important stress for late-planted soybean in high rainfall areas such as the Gulf Coast Region.

Application of a CROPWAT Model to Analyze Crop Yields in Nicaragua

NASA Astrophysics Data System (ADS)

Doria, R.; Byrne, J. M.

2013-12-01

ABSTRACT Changes in climate are likely to influence crop yields due to varying evapotranspiration and precipitation over agricultural regions. In Nicaragua, agriculture is extensive, with new areas of land brought into production as the population increases. Nicaraguan staple food items (maize and beans) are produced mostly by small scale farmers with less than 10 hectares, but they are critical for income generation and food security for rural communities. Given that the majority of these farmers are dependent on rain for crop irrigation, and that maize and beans are sensitive to variations in temperature and rainfall patterns, the present study was undertaken to assess the impact of climate change on these crop yields. Climate data were generated per municipio representing the three major climatic zones of the country: the wet Pacific lowland, the cooler Central highland, and the Caribbean lowland. Historical normal climate data from 1970-2000 (baseline period) were used as input to CROPWAT model to analyze the potential and actual evapotranspiration (ETo and ETa, respectively) that affects crop yields. Further, generated local climatic data of future years (2030-2099) under various scenarios were inputted to the CROPWAT to determine changes in ETo and ETa from the baseline period. Spatial variability maps of both ETo and ETa as well as crop yields were created. Results indicated significant variation in seasonal rainfall depth during the baseline period and predicted decreasing trend in the future years that eventually affects yields. These maps enable us to generate appropriate adaptation measures and best management practices for small scale farmers under future climate change scenarios. KEY WORDS: Climate change, evapotranspiration, CROPWAT, yield, Nicaragua

Consequences of waterlogging in cotton and opportunities for mitigation of yield losses

PubMed Central

Najeeb, Ullah; Bange, Michael P.; Tan, Daniel K. Y.; Atwell, Brian J.

2015-01-01

Climatic variability, typified by erratic heavy-rainfall events, causes waterlogging in intensively irrigated crops and is exacerbated under warm temperature regimes on soils with poor internal drainage. Irrigated cotton is often grown in precisely these conditions, exposing it to waterlogging-induced yield losses after substantial summer rainfall. This calls for a deeper understanding of mechanisms of waterlogging tolerance and its relevance to cotton. Hence this review suggests possible causes of waterlogging-induced yield loss in cotton and approaches to improvement of waterlogging tolerance, drawing upon the slight body of published data in cotton and principles from other species. The yield penalty depends on soil type, phenological stage and cumulative period of root exposure to air-filled porosities below 10 %. Events in the soil include O2 deficiency in the root zone that changes the redox state of nutrients, making them unavailable (e.g. nitrogen) or potentially toxic for plants. Furthermore, root-derived hormones that are transported in the xylem have long been associated with oxygen deficits. These belowground effects (impaired root growth, nutrient uptake and transport, hormonal signalling) affect the shoots, interfering with canopy development, photosynthesis and radiation-use efficiency. Compared with the more waterlogging-tolerant cereals, cotton does not have identified adaptations to waterlogging in the root zone, forming no conspicuous root aerenchyma and having low fermentative activity. We speculate that these factors contribute substantially to the sensitivity of cotton to sustained periods of waterlogging. We discuss the impact of these belowground factors on shoot performance, photosynthesis and yield components. Management practices, i.e. soil aeration, scheduling irrigation and fertilizer application, can reduce waterlogging-induced damage. Limiting ethylene biosynthesis using anti-ethylene agents and down-regulating expression of genes

Separating heat stress from moisture stress: analyzing yield response to high temperature in irrigated maize

NASA Astrophysics Data System (ADS)

Carter, Elizabeth K.; Melkonian, Jeff; Riha, Susan J.; Shaw, Stephen B.

2016-09-01

Several recent studies have indicated that high air temperatures are limiting maize (Zea mays L.) yields in the US Corn Belt and project significant yield losses with expected increases in growing season temperatures. Further work has suggested that high air temperatures are indicative of high evaporative demand, and that decreases in maize yields which correlate to high temperatures and vapor pressure deficits (VPD) likely reflect underlying soil moisture limitations. It remains unclear whether direct high temperature impacts on yields, independent of moisture stress, can be observed under current temperature regimes. Given that projected high temperature and moisture may not co-vary the same way as they have historically, quantitative analyzes of direct temperature impacts are critical for accurate yield projections and targeted mitigation strategies under shifting temperature regimes. To evaluate yield response to above optimum temperatures independent of soil moisture stress, we analyzed climate impacts on irrigated maize yields obtained from the National Corn Growers Association (NCGA) corn yield contests for Nebraska, Kansas and Missouri. In irrigated maize, we found no evidence of a direct negative impact on yield by daytime air temperature, calculated canopy temperature, or VPD when analyzed seasonally. Solar radiation was the primary yield-limiting climate variable. Our analyses suggested that elevated night temperature impacted yield by increasing rates of phenological development. High temperatures during grain-fill significantly interacted with yields, but this effect was often beneficial and included evidence of acquired thermo-tolerance. Furthermore, genetics and management—information uniquely available in the NCGA contest data—explained more yield variability than climate, and significantly modified crop response to climate. Thermo-acclimation, improved genetics and changes to management practices have the potential to partially or completely

Statistical Analysis of Large Simulated Yield Datasets for Studying Climate Effects

NASA Technical Reports Server (NTRS)

Makowski, David; Asseng, Senthold; Ewert, Frank; Bassu, Simona; Durand, Jean-Louis; Martre, Pierre; Adam, Myriam; Aggarwal, Pramod K.; Angulo, Carlos; Baron, Chritian;

On locally and nonlocally related potential systems

NASA Astrophysics Data System (ADS)

Cheviakov, Alexei F.; Bluman, George W.

2010-07-01

For any partial differential equation (PDE) system, a local conservation law yields potential equations in terms of some potential variable, which normally is a nonlocal variable. The current paper examines situations when such a potential variable is a local variable, i.e., is a function of the independent and dependent variables of a given PDE system, and their derivatives. In the case of two independent variables, a simple necessary and sufficient condition is presented for the locality of such a potential variable, and this is illustrated by several examples. As a particular example, two-dimensional reductions of equilibrium equations for fluid and plasma dynamics are considered. It is shown that such reductions with respect to helical, axial, and translational symmetries have conservation laws which yield local potential variables. This leads to showing that the well-known Johnson-Frieman-Kruskal-Oberman (JFKO) and Bragg-Hawthorne (Grad-Shafranov) equations are locally related to the corresponding helically and axially symmetric PDE systems of fluid/plasma dynamics. For the axially symmetric case, local symmetry classifications and arising invariant solutions are compared for the original PDE system and the Bragg-Hawthorne (potential) equation. The potential equation is shown to have additional symmetries, denoted as restricted symmetries. Restricted symmetries leave invariant a family of solutions of a given PDE system but not the whole solution manifold, and hence are not symmetries of the given PDE system. Corresponding reductions are shown to yield solutions, which are not obtained as invariant solutions from local symmetry reduction.

MicroRNA profile of silk gland reveals different silk yields of three silkworm strains.

PubMed

Qin, Sheng; Danso, Blessing; Zhang, Jing; Li, Juan; Liu, Na; Sun, Xia; Hou, Chengxiang; Luo, Heng; Chen, Keping; Zhang, Guozheng; Li, Muwang

2018-05-05

Silk proteins are synthesized and secreted by the silk gland. The differential gene expression in it leads to different silk yield among various silkworm strains. As crucial factors, microRNAs (miRNAs) regulate protein synthesis at post-transcriptional level in silk gland. MiRNAs expression level in the silk gland of three silkworm strains (Jingsong, Lan10 and Dazao) was analyzed and 33 differentially expressed miRNAs (DEMs) were discovered between JingSong (JS) and Lan10 (L10), 60 DEMs between JS and Dazao, 54 DEMs between L10 and Dazao respectively. The DEMs target genes were predicted combing with two different methods and their functions were annotated according to gene ontology. Our previous studies showed that a batch of genes related to silk yield were identified in JS and L10 strains by comparative transcriptome and quantitative trait loci (QTL) method. Thirteen DEMs whose target genes are related to protein biosynthesis processes were screened by combining with these researches. Twelve DEMs potentially regulate nineteen genes which exist in our QTL results. Six common DEMs potentially regulate the genes in both of previous results. Finally, five DEMs were selected to verify their expression levels between JS and L10 by qRT-PCR, which showed similar difference as the results of small RNA-sequencing. MiRNAs in the silk gland may directly affect silk protein biosynthesis in different silkworm strains. In current work, we identified a batch of DEMs which potentially regulate the genes related to silk yield. Further functionally study of these miRNAs will contribute to improve varieties and boost the silk yield. Our research provides a basis for studying these miRNAs and their functions in silk production. Copyright © 2018 Elsevier B.V. All rights reserved.

Yield, pollination aspects and kernel qualities of almond (Prunus amygdalus Batsch) selections trialed in the Southern San Joaquin Valley

USDA-ARS?s Scientific Manuscript database

A field trial was established in the Southern San Joaquin Valley to determine yield potential for nine almond selections grown under commercial conditions. Kernel yields were first quantified in 2008, at the end of the third growing season, and continued through the 2010 harvest. Harvested tonnage...

Influence of management and environment on Australian wheat: information for sustainable intensification and closing yield gaps

NASA Astrophysics Data System (ADS)

Bryan, B. A.; King, D.; Zhao, G.

2014-04-01

In the future, agriculture will need to produce more, from less land, more sustainably. But currently, in many places, actual crop yields are below those attainable. We quantified the ability for agricultural management to increase wheat yields across 179 Mha of potentially arable land in Australia. Using the Agricultural Production Systems Simulator (APSIM), we simulated the impact on wheat yield of 225 fertilization and residue management scenarios at a high spatial, temporal, and agronomic resolution from 1900 to 2010. The influence of management and environmental variables on wheat yield was then assessed using Spearman’s non-parametric correlation test with bootstrapping. While residue management showed little correlation, fertilization strongly increased wheat yield up to around 100 kg N ha-1 yr-1. However, this effect was highly dependent on the key environment variables of rainfall, temperature, and soil water holding capacity. The influence of fertilization on yield was stronger in cooler, wetter climates, and in soils with greater water holding capacity. We conclude that the effectiveness of management intensification to increase wheat yield is highly dependent upon local climate and soil conditions. We provide context-specific information on the yield benefits of fertilization to support adaptive agronomic decision-making and contribute to the closure of yield gaps. We also suggest that future assessments consider the economic and environmental sustainability of management intensification for closing yield gaps.

Process gg{yields}h{sub 0}{yields}{gamma}{gamma} in the Lee-Wick standard model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krauss, F.; Underwood, T. E. J.; Zwicky, R.

2008-01-01

The process gg{yields}h{sub 0}{yields}{gamma}{gamma} is studied in the Lee-Wick extension of the standard model (LWSM) proposed by Grinstein, O'Connell, and Wise. In this model, negative norm partners for each SM field are introduced with the aim to cancel quadratic divergences in the Higgs mass. All sectors of the model relevant to gg{yields}h{sub 0}{yields}{gamma}{gamma} are diagonalized and results are commented on from the perspective of both the Lee-Wick and higher-derivative formalisms. Deviations from the SM rate for gg{yields}h{sub 0} are found to be of the order of 15%-5% for Lee-Wick masses in the range 500-1000 GeV. Effects on the rate formore » h{sub 0}{yields}{gamma}{gamma} are smaller, of the order of 5%-1% for Lee-Wick masses in the same range. These comparatively small changes may well provide a means of distinguishing the LWSM from other models such as universal extra dimensions where same-spin partners to standard model fields also appear. Corrections to determinations of Cabibbo-Kobayashi-Maskawa (CKM) elements |V{sub t(b,s,d)}| are also considered and are shown to be positive, allowing the possibility of measuring a CKM element larger than unity, a characteristic signature of the ghostlike nature of the Lee-Wick fields.« less

Simultaneous improvement of grain yield and protein content in durum wheat by different phenotypic indices and genomic selection.

PubMed

Rapp, M; Lein, V; Lacoudre, F; Lafferty, J; Müller, E; Vida, G; Bozhanova, V; Ibraliu, A; Thorwarth, P; Piepho, H P; Leiser, W L; Würschum, T; Longin, C F H

2018-06-01

Simultaneous improvement of protein content and grain yield by index selection is possible but its efficiency largely depends on the weighting of the single traits. The genetic architecture of these indices is similar to that of the primary traits. Grain yield and protein content are of major importance in durum wheat breeding, but their negative correlation has hampered their simultaneous improvement. To account for this in wheat breeding, the grain protein deviation (GPD) and the protein yield were proposed as targets for selection. The aim of this work was to investigate the potential of different indices to simultaneously improve grain yield and protein content in durum wheat and to evaluate their genetic architecture towards genomics-assisted breeding. To this end, we investigated two different durum wheat panels comprising 159 and 189 genotypes, which were tested in multiple field locations across Europe and genotyped by a genotyping-by-sequencing approach. The phenotypic analyses revealed significant genetic variances for all traits and heritabilities of the phenotypic indices that were in a similar range as those of grain yield and protein content. The GPD showed a high and positive correlation with protein content, whereas protein yield was highly and positively correlated with grain yield. Thus, selecting for a high GPD would mainly increase the protein content whereas a selection based on protein yield would mainly improve grain yield, but a combination of both indices allows to balance this selection. The genome-wide association mapping revealed a complex genetic architecture for all traits with most QTL having small effects and being detected only in one germplasm set, thus limiting the potential of marker-assisted selection for trait improvement. By contrast, genome-wide prediction appeared promising but its performance strongly depends on the relatedness between training and prediction sets.

A new anchialine Stephos Scott from the Yucatan Peninsula with notes on the biogeography and diversity of the genus (Copepoda, Calanoida, Stephidae)

PubMed Central

Suárez-Morales, Eduardo; Gutiérrez-Aguirre, Martha A.; Cervantes-Martínez, Adrián; Iliffe, Thomas M.

2017-01-01

Abstract Surveys of the anchialine crustacean fauna of the Yucatan Peninsula (YP), Mexico, have revealed the occurrence of calanoid copepods. The genus Stephos Scott, 1892, belonging to the family Stephidae is among the most frequent and widely distributed groups in anchialine caves but has not been hitherto recorded from the YP. Recent collections from an anchialine cave in an island off the northern coast of the YP yielded many specimens of a new species of Stephos. The new taxon, S. fernandoi sp. n., is described here based on male and female specimens. The new species is clearly distinguished from its congeners by the following characters: male left fifth leg with three terminal lamellae plus subdistal process, right leg with distal row of peg-like elements; female fifth leg with single long, acute apical process; genital double-somite with two rows each of 4 long spinules adjacent to operculum; legs 2-4 with articulated setae. The diversity of the genus shows regional differences; the Australia-Western Pacific region is the most diverse (eleven species), followed by the Mediterranean (seven species) and the Northeastern Atlantic (six species); only four species are known from the Northwestern Tropical Atlantic (NWTA). The morphology of the female fifth leg was examined to explore possible biogeographic trends in the genus; patterns suggest multiple colonization events in the highly diverse regions and a relatively recent radiation in the NWTA, characterized by anchialine forms. The introduction of stephid copepods in the region may be a relatively recent event derived from colonization of benthopelagic ancestral forms and subsequent invasion onto cave habitats. The new species appears to be linked to the strictly anchialine Miostephos. PMID:28769658

A new anchialine Stephos Scott from the Yucatan Peninsula with notes on the biogeography and diversity of the genus (Copepoda, Calanoida, Stephidae).

PubMed

Suárez-Morales, Eduardo; Gutiérrez-Aguirre, Martha A; Cervantes-Martínez, Adrián; Iliffe, Thomas M

2017-01-01

Surveys of the anchialine crustacean fauna of the Yucatan Peninsula (YP), Mexico, have revealed the occurrence of calanoid copepods. The genus Stephos Scott, 1892, belonging to the family Stephidae is among the most frequent and widely distributed groups in anchialine caves but has not been hitherto recorded from the YP. Recent collections from an anchialine cave in an island off the northern coast of the YP yielded many specimens of a new species of Stephos . The new taxon, S. fernandoi sp. n. , is described here based on male and female specimens. The new species is clearly distinguished from its congeners by the following characters: male left fifth leg with three terminal lamellae plus subdistal process, right leg with distal row of peg-like elements; female fifth leg with single long, acute apical process; genital double-somite with two rows each of 4 long spinules adjacent to operculum; legs 2-4 with articulated setae. The diversity of the genus shows regional differences; the Australia-Western Pacific region is the most diverse (eleven species), followed by the Mediterranean (seven species) and the Northeastern Atlantic (six species); only four species are known from the Northwestern Tropical Atlantic (NWTA). The morphology of the female fifth leg was examined to explore possible biogeographic trends in the genus; patterns suggest multiple colonization events in the highly diverse regions and a relatively recent radiation in the NWTA, characterized by anchialine forms. The introduction of stephid copepods in the region may be a relatively recent event derived from colonization of benthopelagic ancestral forms and subsequent invasion onto cave habitats. The new species appears to be linked to the strictly anchialine Miostephos .

Soybean Photosynthesis and Yield as Influenced by Heterodera glycines, Soil Type and Irrigation.

PubMed

Koenning, S R; Barker, K R

1995-03-01

The effects of soil types and soil water matric pressure on the Heterodera glycines-Glycine max interaction were examined in microplots in 1988 and 1989. Reproduction of H. glycines was restricted in fine-textured soils as compared with coarse-textured ones. Final population densities of this pathogen in both years of the study were greater in nonirrigated soils than in irrigated soils. The net photosynthetic rate of soybean (per unit area of leaf) was suppressed only slightly or not at all in response to infection by H. glycines and other stresses. Relative soybean-yield suppression in response to H. glycines was not affected by water content in fine-textured soils, but slopes of the damage functions were steepest in sand, sandy loam, and muck soils at high water content (irrigated plots). Yield restriction of soybean in response to this pathogen under irrigation was equal to or greater than the yield suppression under dry conditions. Although yield potential may be elevated by irrigation when soil-water content is inadequate, supplemental irrigation cannot be used to circumvent nematode damage to soybean.

Secondary electron emission yield from high aspect ratio carbon velvet surfaces

DOE PAGES

Jin, Chenggang; Ottaviano, Angelica; Raitses, Yevgeny

2017-11-01

The plasma electrons bombarding a plasma-facing wall surface can induce secondary electron emission (SEE) from the wall. A strong SEE can enhance the power losses by reducing the wall sheath potential and thereby increasing the electron flux from the plasma to the wall. The use of the materials with surface roughness and the engineered materials with surface architecture is known to reduce the effective SEE by trapping the secondary electrons. In this work, we demonstrate a 65% reduction of SEE yield using a velvet material consisting of high aspect ratio carbon fibers. The measurements of SEE yield for different velvetmore » samples using the electron beam in vacuum demonstrate the dependence of the SEE yield on the fiber length and the packing density, which is strongly affected by the alignment of long velvet fibers with respect to the electron beam impinging on the velvet sample. Furthermore, the results of SEE measurements support the previous observations of the reduced SEE measured in Hall thrusters.« less

Growth and yield models for central hardwoods

Treesearch

Martin E. Dale; Donald E. Hilt

1989-01-01

Over the last 20 years computers have become an efficient tool to estimate growth and yield. Computerized yield estimates vary from simple approximation or interpolation of traditional normal yield tables to highly sophisticated programs that simulate the growth and yield of each individual tree.

Microeconomics of yield learning and process control in semiconductor manufacturing

NASA Astrophysics Data System (ADS)

Monahan, Kevin M.

2003-06-01

Simple microeconomic models that directly link yield learning to profitability in semiconductor manufacturing have been rare or non-existent. In this work, we review such a model and provide links to inspection capability and cost. Using a small number of input parameters, we explain current yield management practices in 200mm factories. The model is then used to extrapolate requirements for 300mm factories, including the impact of technology transitions to 130nm design rules and below. We show that the dramatic increase in value per wafer at the 300mm transition becomes a driver for increasing metrology and inspection capability and sampling. These analyses correlate well wtih actual factory data and often identify millions of dollars in potential cost savings. We demonstrate this using the example of grating-based overlay metrology for the 65nm node.

Estimating oak growth and yield

Treesearch

Martin E. Dale; Donald E. Hilt

1989-01-01

Yields from upland oak stands vary widely from stand to stand due to differences in age, site quality, species composition, and stand structure. Cutting history and other past disturbances such as grazing or fire also affect yields.

Ensemble yield simulations: Using heat-tolerant and later-maturing varieties to adapt to climate warming.

PubMed

Zhang, Yi; Zhao, Yanxia

2017-01-01

The use of modern crop varieties is a dominant method of obtaining high yields in crop production. Efforts to identify suitable varieties, with characteristics that would increase crop yield under future climate conditions, remain essential to developing sustainable agriculture and food security. This work aims to evaluate potential genotypic adaptations (i.e., using varieties with increased ability to produce desirable grain numbers under high temperatures and with enhanced thermal time requirements during the grain-filling period) to cope with the negative impacts of climate change on maize yield. The contributions of different options were investigated at six sites in the North China Plain using the APSIM model and the outputs of 8 GCMs under RCP4.5 scenarios. It was found that without considering adaptation options, mean maize yield would decrease by 7~18% during 2010-2039 relative to 1976-2005. A large decrease in grain number relative to stabilized grain weight decreased maize yield under future climate scenarios. Using heat-tolerant varieties, maize yield could increase on average by 6% to 10%. Using later maturing varieties, e.g., enhanced thermal time requirements during the grain-filling period, maize yield could increase by 7% to 10%. The optimal adaptation options were site specific.

Ensemble yield simulations: Using heat-tolerant and later-maturing varieties to adapt to climate warming

PubMed Central

Zhang, Yi

2017-01-01

The use of modern crop varieties is a dominant method of obtaining high yields in crop production. Efforts to identify suitable varieties, with characteristics that would increase crop yield under future climate conditions, remain essential to developing sustainable agriculture and food security. This work aims to evaluate potential genotypic adaptations (i.e., using varieties with increased ability to produce desirable grain numbers under high temperatures and with enhanced thermal time requirements during the grain-filling period) to cope with the negative impacts of climate change on maize yield. The contributions of different options were investigated at six sites in the North China Plain using the APSIM model and the outputs of 8 GCMs under RCP4.5 scenarios. It was found that without considering adaptation options, mean maize yield would decrease by 7~18% during 2010–2039 relative to 1976–2005. A large decrease in grain number relative to stabilized grain weight decreased maize yield under future climate scenarios. Using heat-tolerant varieties, maize yield could increase on average by 6% to 10%. Using later maturing varieties, e.g., enhanced thermal time requirements during the grain-filling period, maize yield could increase by 7% to 10%. The optimal adaptation options were site specific. PMID:28459880

Airborne monitoring of crop canopy temperatures for irrigation scheduling and yield prediction

NASA Technical Reports Server (NTRS)

Millard, J. P.; Jackson, R. D.; Goettelman, R. C.; Reginato, R. J.; Idso, S. B.; Lapado, R. L.

1977-01-01

Airborne and ground measurements were made on April 1 and 29, 1976, over a USDA test site consisting mostly of wheat in various stages of water stress, but also including alfalfa and bare soil. These measurements were made to evaluate the feasibility of measuring crop temperatures from aircraft so that a parameter termed stress degree day, SDD, could be computed. Ground studies have shown that SDD is a valuable indicator of a crop's water needs, and that it can be related to irrigation scheduling and yield. The aircraft measurement program required predawn and afternoon flights coincident with minimum and maximum crop temperatures. Airborne measurements were made with an infrared line scanner and with color IR photography. The scanner data were registered, subtracted, and color-coded to yield pseudo-colored temperature-difference images. Pseudo-colored images reading directly in daily SDD increments were also produced. These maps enable a user to assess plant water status and thus determine irrigation needs and crop yield potentials.

Fission yield and criticality excursion code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blanchard, A.

2000-06-30

The ANSI/ANS 8.3 standard allows a maximum yield not to exceed 2 x 10 fissions to calculate requiring the alarm system to be effective. It is common practice to use this allowance or to develop some other yield based on past criticality accident history or excursion experiments. The literature on the subject of yields discusses maximum yields larger and somewhat smaller than the ANS 8.3 permissive value. The ability to model criticality excursions and vary the various parameters to determine a credible maximum yield for operational specific cases has been available for some time but is not in common usemore » by criticality safety specialists. The topic of yields for various solution, metal, oxide powders, etc. in various geometry's and containers has been published by laboratory specialists or university staff and students for many decades but have not been available to practitioners. The need for best-estimate calculations of fission yields with a well-validated criticality excursion code has long been recognized. But no coordinated effort has been made so far to develop a generalized and well-validated excursion code for different types of systems. In this paper, the current practices to estimate fission yields are summarized along with its shortcomings for the 12-Rad zone (at SRS) and Criticality Alarm System (CAS) calculations. Finally the need for a user-friendly excursion code is reemphasized.« less

Hauser-Feshbach fission fragment de-excitation with calculated macroscopic-microscopic mass yields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaffke, Patrick John; Talou, Patrick; Sierk, Arnold John

The Hauser-Feshbach statistical model is applied to the de-excitation of primary fission fragments using input mass yields calculated with macroscopic-microscopic models of the potential energy surface. We test the sensitivity of the prompt fission observables to the input mass yields for two important reactions, 235U (n th, f) and 239Pu (n th, f) , for which good experimental data exist. General traits of the mass yields, such as the location of the peaks and their widths, can impact both the prompt neutron and γ-ray multiplicities, as well as their spectra. Specifically, we use several mass yields to determine a linear correlation between the calculated prompt neutron multiplicitymore » $$\\bar{v}$$ and the average heavy-fragment mass $$\\langle$$A h$$\\rangle$$ of the input mass yields ∂$$\\bar{v}$$/∂ $$\\langle$$A h$$\\rangle$$ = ± 0.1 (n / f )/u . The mass peak width influences the correlation between the total kinetic energy of the fission fragments and the total number of prompt neutrons emitted, $$\\bar{v}_T$$ ( TKE ) . Finally, typical biases on prompt particle observables from using calculated mass yields instead of experimental ones are δ$$\\bar{v}$$ = 4 % for the average prompt neutron multiplicity, δ$$\\overline{M}_γ$$ = 1% for the average prompt γ-ray multiplicity, δ$$\\bar{ε}$$ $$LAB\\atop{n}$$ = 1 % for the average outgoing neutron energy, δ$$\\bar{ε}_γ$$ = 1 % for the average γ-ray energy, and δ $$\\langle$$TKE$$\\rangle$$ = 0.4 % for the average total kinetic energy of the fission fragments.« less

Hauser-Feshbach fission fragment de-excitation with calculated macroscopic-microscopic mass yields

DOE PAGES

Jaffke, Patrick John; Talou, Patrick; Sierk, Arnold John; ...

2018-03-15

The Hauser-Feshbach statistical model is applied to the de-excitation of primary fission fragments using input mass yields calculated with macroscopic-microscopic models of the potential energy surface. We test the sensitivity of the prompt fission observables to the input mass yields for two important reactions, 235U (n th, f) and 239Pu (n th, f) , for which good experimental data exist. General traits of the mass yields, such as the location of the peaks and their widths, can impact both the prompt neutron and γ-ray multiplicities, as well as their spectra. Specifically, we use several mass yields to determine a linear correlation between the calculated prompt neutron multiplicitymore » $$\\bar{v}$$ and the average heavy-fragment mass $$\\langle$$A h$$\\rangle$$ of the input mass yields ∂$$\\bar{v}$$/∂ $$\\langle$$A h$$\\rangle$$ = ± 0.1 (n / f )/u . The mass peak width influences the correlation between the total kinetic energy of the fission fragments and the total number of prompt neutrons emitted, $$\\bar{v}_T$$ ( TKE ) . Finally, typical biases on prompt particle observables from using calculated mass yields instead of experimental ones are δ$$\\bar{v}$$ = 4 % for the average prompt neutron multiplicity, δ$$\\overline{M}_γ$$ = 1% for the average prompt γ-ray multiplicity, δ$$\\bar{ε}$$ $$LAB\\atop{n}$$ = 1 % for the average outgoing neutron energy, δ$$\\bar{ε}_γ$$ = 1 % for the average γ-ray energy, and δ $$\\langle$$TKE$$\\rangle$$ = 0.4 % for the average total kinetic energy of the fission fragments.« less

Hormonal and metabolic regulation of source-sink relations under salinity and drought: from plant survival to crop yield stability.

PubMed

Albacete, Alfonso A; Martínez-Andújar, Cristina; Pérez-Alfocea, Francisco

2014-01-01

Securing food production for the growing population will require closing the gap between potential crop productivity under optimal conditions and the yield captured by farmers under a changing environment, which is termed agronomical stability. Drought and salinity are major environmental factors contributing to the yield gap ultimately by inducing premature senescence in the photosynthetic source tissues of the plant and by reducing the number and growth of the harvestable sink organs by affecting the transport and use of assimilates between and within them. However, the changes in source-sink relations induced by stress also include adaptive changes in the reallocation of photoassimilates that influence crop productivity, ranging from plant survival to yield stability. While the massive utilization of -omic technologies in model plants is discovering hundreds of genes with potential impacts in alleviating short-term applied drought and salinity stress (usually measured as plant survival), only in relatively few cases has an effect on crop yield stability been proven. However, achieving the former does not necessarily imply the latter. Plant survival only requires water status conservation and delayed leaf senescence (thus maintaining source activity) that is usually accompanied by growth inhibition. However, yield stability will additionally require the maintenance or increase in sink activity in the reproductive structures, thus contributing to the transport of assimilates from the source leaves and to delayed stress-induced leaf senescence. This review emphasizes the role of several metabolic and hormonal factors influencing not only the source strength, but especially the sink activity and their inter-relations, and their potential to improve yield stability under drought and salinity stresses. © 2013.

Virtual chromoendoscopy improves the diagnostic yield of small bowel capsule endoscopy in obscure gastrointestinal bleeding.

PubMed

Boal Carvalho, Pedro; Magalhães, Joana; Dias de Castro, Francisca; Gonçalves, Tiago Cúrdia; Rosa, Bruno; Moreira, Maria João; Cotter, José

2016-02-01

Small bowel capsule endoscopy represents the initial investigation for obscure gastrointestinal bleeding. Flexible spectral imaging colour enhancement (FICE) is a virtual chromoendoscopy technique designed to enhance mucosal lesions, available in different settings according to light wavelength-- FICE1, 2 and 3. To compare the diagnostic yield of FICE1 and white light during capsule endoscopy in patients with obscure gastrointestinal bleeding. Retrospective single-centre study including 60 consecutive patients referred for small bowel capsule endoscopy for obscure gastrointestinal bleeding. Endoscopies were independently reviewed in FICE1 and white light; findings were then reviewed by another researcher, establishing a gold standard. Diagnostic yield was defined as the presence of lesions with high bleeding potential (P2) angioectasias, ulcers or tumours. Diagnostic yield using FICE1 was significantly higher than white light (55% vs. 42%, p=0.021). A superior number of P2 lesions was detected with FICE1 (74 vs. 44, p=0.003), particularly angioectasias (54 vs. 26, p=0.002), but not ulcers or tumours. FICE1 was significantly superior to white light, resulting in a 13% improvement in diagnostic yield, and potentially bleeding lesions particularly angioectasias were more often observed. Our results support the use of FICE1 while reviewing small bowel capsule endoscopy for obscure gastrointestinal bleeding. Copyright © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Making biodiversity-friendly cocoa pay: combining yield, certification, and REDD for shade management.

PubMed

Waldron, A; Justicia, R; Smith, L E

2015-03-01

The twin United Nations' Millennium Development Goals of biodiversity preservation and poverty reduction both strongly depend on actions in the tropics. In particular, traditional agroforestry could be critical to both biological conservation and human livelihoods in human-altered rainforest areas. However, traditional agroforestry is rapidly disappearing, because the system itself is economically precarious, and because the forest trees that shade traditional crops are now perceived to be overly detrimental to agricultural yield. Here, we show a case where the commonly used agroforestry shade metric, canopy cover, would indeed suggest complete removal of shade trees to maximize yield, with strongly negative biodiversity and climate implications. However, a yield over 50% higher was achievable if approximately 100 shade trees per hectare were planted in a spatially organized fashion, a win-win for biodiversity and the smallholder. The higher yield option was detected by optimizing simultaneously for canopy cover, and a second shade metric, neighboring tree density, which was designed to better capture the yield value of ecological services flowing from forest trees. Nevertheless, even a 50% yield increase may prove insufficient to stop farmers converting away from traditional agroforestry. To further increase agroforestry rents, we apply our results to the design of a sustainable certification (eco-labelling) scheme for cocoa-based products in a biodiversity hotspot, and consider their implications for the use of the United Nations REDD (reducing emissions from deforestation and forest degradation) program in agroforestry systems. Combining yield boost, certification, and REDD has the potential to incentivize eco-friendly agroforestry and lift smallholders out of poverty, simultaneously.

Altitude-Wind-Tunnel Investigation of Performance of Several Propellers on YP-47M Airplane at High Blade Loading. 2; Curtiss 838-1C2-18R1 Four-Blade Propeller

NASA Technical Reports Server (NTRS)

Wallner, Lewis E.; Sorin, Solomon M.

1946-01-01

An investigation was conducted in the Cleveland altitude wind tunnel to determine the performance of a Curtiss propeller with four 838-lC2-lSRl blades on a YP-47M airplane at high blade loadings and engine powers. The study was made for a range of power coefficients between 0.30 and 1.00 at free-stream Mach numbers of 0.40 and 0.50. The results of the force measurements indicate primarily the trend of propeller efficiency for changes in power coefficient or advance-diameter ratio, inasmuch as corrections for the effects of tunnel-wall constriction on the installation have not been applied. Slip-stream pressure surveys across the propeller disk are presented to illustrate blade thrust load distribution for several operating conditions. At a free-stream Mach number of 0.40, nearly constant peak efficiencies were obtained at power coefficients from 0.30 to 0.70. A change in power coefficient from 0.70 to 0.90 reduced the peak efficiency about 5 percent. Blade stall at the tip sections became evident for a power coefficient of 0.91 when the advance-diameter ratio was reduced to 1.87. At a free-stream Mach number of 0.50, the highest propeller efficiencies were obtained for power coefficients from 0.80 to 1.00 at advance-diameter ratios above 2.90. At advance-diameter ratios below 2.90, the highest efficiencies were obtained for power coefficients of 0.60 and 0.70. The envelope of the efficiency curves decreased about 12 percent between advance-diameter ratios of 2.60 and 4.20. Local compressibility effects became evident for a power coefficient of 0.40 when the advance-diameter ratio was decreased to 1.75.

Improving the yield from fermentative hydrogen production.

PubMed

Kraemer, Jeremy T; Bagley, David M

2007-05-01

Efforts to increase H(2) yields from fermentative H(2) production include heat treatment of the inoculum, dissolved gas removal, and varying the organic loading rate. Although heat treatment kills methanogens and selects for spore-forming bacteria, the available evidence indicates H(2) yields are not maximized compared to bromoethanesulfonate, iodopropane, or perchloric acid pre-treatments and spore-forming acetogens are not killed. Operational controls (low pH, short solids retention time) can replace heat treatment. Gas sparging increases H(2) yields compared to un-sparged reactors, but no relationship exists between the sparging rate and H(2) yield. Lower sparging rates may improve the H(2) yield with less energy input and product dilution. The reasons why sparging improves H(2) yields are unknown, but recent measurements of dissolved H(2) concentrations during sparging suggest the assumption of decreased inhibition of the H(2)-producing enzymes is unlikely. Significant disagreement exists over the effect of organic loading rate (OLR); some studies show relatively higher OLRs improve H(2) yield while others show the opposite. Discovering the reasons for higher H(2) yields during dissolved gas removal and changes in OLR will help improve H(2) yields.

Strategy For Yield Control And Enhancement In VLSI Wafer Manufacturing

NASA Astrophysics Data System (ADS)

Neilson, B.; Rickey, D.; Bane, R. P.

1988-01-01

In most fully utilized integrated circuit (IC) production facilities, profit is very closely linked with yield. In even the most controlled manufacturing environments, defects due to foreign material are a still major contributor to yield loss. Ideally, an IC manufacturer will have ample engineering resources to address any problem that arises. In the real world, staffing limitations require that some tasks must be left undone and potential benefits left unrealized. Therefore, it is important to prioritize problems in a manner that will give the maximum benefit to the manufacturer. When offered a smorgasbord of problems to solve, most people (engineers included) will start with what is most interesting or the most comfortable to work on. By providing a system that accurately predicts the impact of a wide variety of defect types, a rational method of prioritizing engineering effort can be made. To that effect, a program was developed to determine and rank the major yield detractors in a mixed analog/digital FET manufacturing line. The two classical methods of determining yield detractors are chip failure analysis and defect monitoring on drop in test die. Both of these methods have short comings: 1) Chip failure analysis is painstaking and very time consuming. As a result, the sample size is very small. 2) Drop in test die are usually designed for device parametric analysis rather than defect analysis. To provide enough wafer real estate to do meaningful defect analysis would render the wafer worthless for production. To avoid these problems, a defect monitor was designed that provided enough area to detect defects at the same rate or better than the NMOS product die whose yield was to be optimized. The defect monitor was comprehensive and electrically testable using such equipment as the Prometrix LM25 and other digital testers. This enabled the quick accumulation of data which could be handled statistically and mapped individually. By scaling the defect densities

Useful ion yields for Cameca IMS 3f and 6f SIMS: Limits on quantitative analysis

USGS Publications Warehouse

Hervig, R.L.; Mazdab, F.K.; Williams, Pat; Guan, Y.; Huss, G.R.; Leshin, L.A.

2006-01-01

The useful yields (ions detected/atom sputtered) of major and trace elements in NIST 610 glass were measured by secondary ion mass spectrometry (SIMS) using Cameca IMS 3f and 6f instruments. Useful yields of positive ions at maximum transmission range from 10-4 to 0.2 and are negatively correlated with ionization potential. We quantified the decrease in useful yields when applying energy filtering or high mass resolution techniques to remove molecular interferences. The useful yields of selected negative ions (O, S, Au) in magnetite and pyrite were also determined. These data allow the analyst to determine if a particular analysis (trace element contents or isotopic ratio) can be achieved, given the amount of sample available and the conditions of the analysis. ?? 2005 Elsevier B.V. All rights reserved.

Electron-induced electron yields of uncharged insulating materials

NASA Astrophysics Data System (ADS)

Hoffmann, Ryan Carl

Presented here are electron-induced electron yield measurements from high-resistivity, high-yield materials to support a model for the yield of uncharged insulators. These measurements are made using a low-fluence, pulsed electron beam and charge neutralization to minimize charge accumulation. They show charging induced changes in the total yield, as much as 75%, even for incident electron fluences of <3 fC/mm2, when compared to an uncharged yield. The evolution of the yield as charge accumulates in the material is described in terms of electron recapture, based on the extended Chung and Everhart model of the electron emission spectrum and the dual dynamic layer model for internal charge distribution. This model is used to explain charge-induced total yield modification measured in high-yield ceramics, and to provide a method for determining electron yield of uncharged, highly insulating, high-yield materials. A sequence of materials with progressively greater charge susceptibility is presented. This series starts with low-yield Kapton derivative called CP1, then considers a moderate-yield material, Kapton HN, and ends with a high-yield ceramic, polycrystalline aluminum oxide. Applicability of conductivity (both radiation induced conductivity (RIC) and dark current conductivity) to the yield is addressed. Relevance of these results to spacecraft charging is also discussed.

Effect of foliar application of glyphosate and cobalt on sugarcane yields and quality

USDA-ARS?s Scientific Manuscript database

Sugarcane is one of the principal crops of the world, and is used in the production of sugar, alcohol and clean energy. In many sugarcane producing regions of the world selected herbicides, insecticides and fungicides are being evaluated for their potential bioactivator effects on sugarcane yields. ...

Yields of Bacterial Cells from Hydrocarbons

PubMed Central

Wodzinski, Richard S.; Johnson, Marvin J.

1968-01-01

A strain of Nocardia and one of Pseudomonas, both isolated on pristane (2,6,10,14-tetramethylpentadecane), gave cell yields of approximately 100% on n-octadecane and pristane. Both organisms grew more rapidly on the n-octadecane than on the pristane. A mixed culture, isolated on 3-methylheptane, whose two components were identified as species of Pseudomonas and of Nocardia, gave approximately 100% cell yields and grew with generation times of about 5 hr on n-heptane, n-octane, and 2-methylheptane. The generation time on 3-methylheptane was 8.6 hr and the cell yield was only 79%. A strain of Pseudomonas isolated from naphthalene enrichments and one from phenanthrene enrichments both gave a cell yield of 50% on naphthalene. The phenanthrene isolate gave a cell yield of 40% on phenanthrene. A Nocardia species isolated on benzene gave a 79% cell yield on benzene. The generation times of the bacteria isolated on aromatic hydrocarbons were related to the solubility of the aromatic hydrocarbons on which they were grown; the more insoluble hydrocarbons gave slower growth. PMID:5726161