29 research outputs found

    Age of Transplant and Row Spacing Effects on Growth, Yield and Yield Components of Chilli Pepper (Capsicum annuum L.)

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    Two field experiments were conducted for two years (2013 and 2014) at the Multipurpose crop nursery of the University of Education, Winneba, Mampong-campus from May to September to evaluate the effect of three transplanting ages (30, 37 and 44 days) and four row spacing (30 x 30 cm, 40 x 30 cm, 50 x 30 cm and 60 x 30cm) on growth, yield and yield components of pepper. The experimental design used was a 3 x 4 factorial in randomized complete block design with three replicates for both experiments. The results showed that 44 aged transplants had the highest yield during the 2013 cropping season, tallest plant in both cropping seasons, highest number of branches and canopy width for the entire 2014 cropping season. The 30 aged transplants differed significantly from the other aged transplants in number of fruits per plant and widest fruit diameter during the 2013 cropping season. The 40 x 30 cm row spacing had the tallest plant and highest number of branches from 8 to 10 weeks after transplanting in both cropping seasons. The 30 x 30 cm row spacing differed significantly from the 50 x 30 cm and 60 x 30 cm row spacing in fruit yield during the 2013 cropping season. The 60 x 30 cm row spacing had the longest fruit length and the heaviest fruit weight per plant during the 2013 cropping season. It is concluded that for high fruit yield, farmers are to transplant pepper seedlings at 44 days using 30 x 30 cm row spacing

    Climate predicts geographic and temporal variation in mosquito-borne disease dynamics on two continents

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    Funding: J.M.C., A.D.L., E.F.L., and E.A.M. were supported by a Stanford Woods Institute for the Environment—Environmental Ventures Program grant (PIs: E.A.M., A.D.L., and E.F.L.). E.A.M. was also supported by a Hellman Faculty Fellowship and a Terman Award. A.D.L., B.A.N., F.M.M., E.N.G.S., M.S.S., A.R.K., R.D., A.A., and H.N.N. were supported by a National Institutes of Health R01 grant (AI102918; PI: A.D.L.). E.A.M., A.M.S.I., and S.J.R. were supported by a National Science Foundation (NSF) Ecology and Evolution of Infectious Diseases (EEID) grant (DEB-1518681), and A.M.S.I. and S.J.R. were also supported by an NSF DEB RAPID grant (1641145). E.A.M. was also supported by a National Institute of General Medical Sciences Maximizing Investigators’ Research Award grant (R35GM133439) and an NSF and Fogarty International Center EEID grant (DEB-2011147).Climate drives population dynamics through multiple mechanisms, which can lead to seemingly context-dependent effects of climate on natural populations. For climate-sensitive diseases, such as dengue, chikungunya, and Zika, climate appears to have opposing effects in different contexts. Here we show that a model, parameterized with laboratory measured climate-driven mosquito physiology, captures three key epidemic characteristics across ecologically and culturally distinct settings in Ecuador and Kenya: the number, timing, and duration of outbreaks. The model generates a range of disease dynamics consistent with observed Aedes aegypti abundances and laboratory-confirmed arboviral incidence with variable accuracy (28-85% for vectors, 44-88% for incidence). The model predicted vector dynamics better in sites with a smaller proportion of young children in the population, lower mean temperature, and homes with piped water and made of cement. Models with limited calibration that robustly capture climate-virus relationships can help guide intervention efforts and climate change disease projections.Publisher PDFPeer reviewe

    Detection of a tropospheric ozone anomaly using a newly developed ozone retrieval algorithm for an up-looking infrared interferometer

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    Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 114 (2009): D06304, doi:10.1029/2008JD010270.On 2 June 2003, the Baltimore Bomem Atmospheric Emitted Radiance Interferometer (BBAERI) recorded an infrared spectral time series indicating the presence of a tropospheric ozone anomaly. The measurements were collected during an Atmospheric Infrared Sounder (AIRS) validation campaign called the 2003 AIRS BBAERI Ocean Validation Experiment (ABOVE03) conducted at the United States Coast Guard Chesapeake Light station located 14 miles due east of Virginia Beach, Virginia (36.91°N, 75.71°W). Ozone retrievals were performed with the Kurt Lightner Ozone BBAERI Retrieval (KLOBBER) algorithm, which retrieves tropospheric column ozone, surface to 300 mbar, from zenith-viewing atmospheric thermal emission spectra. KLOBBER is modeled after the AIRS retrieval algorithm consisting of a synthetic statistical regression followed by a physical retrieval. The physical retrieval is implemented using the k-Compressed Atmospheric Radiative Transfer Algorithm (kCARTA) to compute spectra. The time series of retrieved integrated ozone column on 2 June 2003 displays spikes of about 10 Dobson units, well above the error of the KLOBBER algorithm. Using instrumentation at Chesapeake Light, satellite imaging, trace gas retrievals from satellites, and Potential Vorticity (PV) computations, it was determined that these sudden increases in column ozone likely were caused by a combination of midtropospheric biomass burning products from forest fires in Siberia, Russia, and stratospheric intrusion by a tropopause fold occurring over central Canada and the midwestern United States.NASA for its support through grant NAG5- 1156-7 for AIRS Validation and grant NNG04GN42G for development of AIRS trace gas products, and through a subcontract with JPL on the AIRS Project prime contract NAS7-03001 for continuing optimization and validation of AIRS trace gas products.

    Evaluation of the MOCAGE Chemistry Transport Model during the ICARTT/ITOP Experiment

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    We evaluate the Meteo-France global chemistry transport 3D model MOCAGE (MOdele de Chimie Atmospherique a Grande Echelle) using the important set of aircraft measurements collected during the ICARRT/ITOP experiment. This experiment took place between US and Europe during summer 2004 (July 15-August 15). Four aircraft were involved in this experiment providing a wealth of chemical data in a large area including the North East of US and western Europe. The model outputs are compared to the following species of which concentration is measured by the aircraft: OH, H2O2, CO, NO, NO2, PAN, HNO3, isoprene, ethane, HCHO and O3. Moreover, to complete this evaluation at larger scale, we used also satellite data such as SCIAMACHY NO2 and MOPITT CO. Interestingly, the comprehensive dataset allowed us to evaluate separately the model representation of emissions, transport and chemical processes. Using a daily emission source of biomass burning, we obtain a very good agreement for CO while the evaluation of NO2 points out incertainties resulting from inaccurate ratio of emission factors of NOx/CO. Moreover, the chemical behavior of O3 is satisfactory as discussed in the paper

    From Preparedness to Coordination: Operational Excellence in Post-disaster Supply Chain Management in Africa

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    Preparation and coordination have come to dominate discourse on operational excellence in post disaster supply chain management. In this paper we explore the critical success factors (CSF) of operations excellence in post-disaster operations management in Africa, using in-depth interviews with disaster management practitioners. Available studies have often focused on the commercial supply chains, but rarely on the critical success factors in service excellence in post disaster management operations in Africa. Using in-depth semi-structured interviews and desk-top data collection techniques from disaster management experts in Ghana a number of factors were identified. Employing thematic data analysis technique, these factors were categorised into eight (8) themes: management and administration, resources, political, governance structure, socio-cultural, education and training, infrastructure, and stakeholder involvement and co-operation

    Sources of increase in lowermost stratospheric sulphurous and carbonaceous aerosol background concentrations during 1999–2008 derived from CARIBIC flights

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    This study focuses on sulphurous and carbonaceous aerosol, the major constituents of particulate matter in the lowermost stratosphere (LMS), based on in situ measurements from 1999 to 2008. Aerosol particles in the size range of 0.08–2 ”m were collected monthly during intercontinental flights with the CARIBIC passenger aircraft, presenting the first long-term study on carbonaceous aerosol in the LMS. Elemental concentrations were derived via subsequent laboratory-based ion beam analysis. The stoichiometry indicates that the sulphurous fraction is sulphate, while an O/C ratio of 0.2 indicates that the carbonaceous aerosol is organic. The concentration of the carbonaceous component corresponded on average to approximately 25% of that of the sulphurous, and could not be explained by forest fires or biomass burning, since the average mass ratio of Fe to K was 16 times higher than typical ratios in effluents from biomass burning. The data reveal increasing concentrations of particulate sulphur and carbon with a doubling of particulate sulphur from 1999 to 2008 in the northern hemisphere LMS. Periods of elevated concentrations of particulate sulphur in the LMS are linked to downward transport of aerosol from higher altitudes, using ozone as a tracer for stratospheric air. Tropical volcanic eruptions penetrating the tropical tropopause are identified as the likely cause of the particulate sulphur and carbon increase in the LMS, where entrainment of lower tropospheric air into volcanic jets and plumes could be the cause of the carbon increase

    Springtime Arctic aerosol: Smoke versus Haze, a case study for March 2008

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    During March 2008 photometer observations of Arctic aerosol were performed both at a Russian ice-floe drifting station (NP-35) at the central Arctic ocean (56.7e42.0 E, 85.5e84.2 N) and at Ny-Ålesund, Spitsbergen (78.9 N, 11.9 E). Next to a persistent increase of AOD over NP-35, two pronounced aerosol events have been recorded there, one originating from early season forest fires close to the city of Khabarovsk (“Arctic Smoke”), the other one showed trajectories from central Russia and resembled more the classical Arctic Haze. The latter event has also been recorded two days later over Ny-Ålesund, both in photometer and lidar. From these remote sensing instruments volume distribution functions are derived and discussed. Only subtle differences between the smoke and the haze event have been found in terms of particle microphysics. Different trajectory analysis, driven by NCEP and ECMWF have been performed and compared. For the data set presented here the meteorological field, due to sparseness of data in the central Arctic, mainly limits the precision of the air trajectories

    The intergroup sensitivity effect in mergers and acquisitions: Testing the role of merger motives

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    Research has shown that people are more defensive to criticism when it stems from an outgroup member, compared to an ingroup member (the intergroup sensitivity effect: ISE). We conducted two online vignette experiments to examine the ISE in the context of an organizational merger and the role of merger motives for the ISE. We predicted that the ISE would also emerge in mergers and acquisitions (M&As), but people would respond less negatively to criticism from the outgroup when the motive for the merger is described as achieving synergies rather than growth. In Experiment 1 (N = 452), which did not mention any motives behind the acquisition, a significant ISE emerged. Experiment 2 (N = 587) again showed an ISE regardless of the merger motive. In both experiments, the ISE was mediated by perceptions of the outgroup criticism as less legitimate and constructive. Overall, this research points to the intergroup sensitivity effect as a relevant phenomenon during post-merger integration
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