216 research outputs found
Development and Evaluation of a Low-Cost Probe-Type Instrument to Measure the Equilibrium Moisture Content of Grain
Storage of grain in bags is common in Africa, Asia, and many other less developed countries making a bag probing method well-suited for moisture content (MC) measurement. A low-cost meter was developed under a USAID project to reduce post-harvest loss (PHL). The meter, referred to as the PHL meter, measures the MC of maize and other grains based on relative humidity (RH) and temperature (T) measurements obtained by a small digital sensor located in the tip of a tubular probe that can be inserted into bags of grain or other grain bulks. Measurements are used by equilibrium moisture content (EMC) equations programmed into the meter to predict MC. A handheld reader connected to the probe provides a user interface.
The PHL moisture meter was evaluated based on laboratory studies in the United States and field studies in Ghana. Meter readings from field studies were compared to two commercial meters, a John Deere Chek-Plus-SW08120 grain moisture tester and a DICKEY-john GAC® 2100 Agri meter. The John Deere portable moisture meter is a low-cost meter by developed country standards (~US$250, 2016 price); the GAC 2100 bench-top moisture meter is an approved moisturetester by the Grain Inspection, Packers and Stockyards Administration (GIPSA) and has been a highly regarded and used electronic meter. Laboratory studies indicated that the PHL meter may require up to 6 min to take a measurement because of the time required by the probe tip and sensor to equilibrate to grain conditions. Methods to reduce the measurement time by measuring temporal equilibration rates were developed. These can be programmed into the reader to shorten measurement time for many conditions. The accuracy of the PHL moisture meter was comparable to the GAC 2100 moisture meter for maize below 15% MCwb. Average differences showed a positive offset of 0.45% for the PHL meter relative to the GAC 2100. The PHL meter provided an effective tool to probe bulk grain and bags
Evaluation of plastic and steel bins for protection of stored maize against Insect Infestation in Ghana: Poster
Maize is a staple food in Ghana where there is ever increasing demand for its use to also support poultry and livestock production. However, post-harvest loss of maize is high in Ghana. This study evaluated the effectiveness of plastic and steel bins as bulk storage structures to reduce maize post-harvest loss in Ejura, Ghana during the period from February 2016 to January 2017. Maize pre-disinfested with a solar biomass hybrid dryer was stored in the following treatments: i. a white 7-ton plastic bin filled with untreated maize, ii. agreen 7-ton plastic bin filled with untreated maize, iii.a 6-ton Kikapu steel bin filled with untreated maize, iv. six 50-kg polypropylene (PP) bags filled with maize treated with Betallic Super (80 g pirimiphos-methyl and 15 g permethrin per liter as an emulsifiable concentrate (EC)), and v. six 50-kg PP bags filled with untreated maize ascontrol. Moisture content, insect pests, insect damaged kernels (IDK), grain weight loss, aflatoxin and fumonisin levels data were collected monthly. Sitophilus zeamais, Tribolium castaneum, Cathartus quadricollis, and Cryptolestes ferrugineus were the dominant insect species collected from maize samples. At the end of 12 months of storage, % IDK in the control was >17% while IDK values in the other treatments were <3%. Mean grain weight losses of <1% were recorded in the bin treatments. Mycotoxin levels in the control were above the allowable threshold of 15 ppb. Our data suggest that use of plastic and steel bins has potential to reduce post-harvest loss of maize during storage.Maize is a staple food in Ghana where there is ever increasing demand for its use to also support poultry and livestock production. However, post-harvest loss of maize is high in Ghana. This study evaluated the effectiveness of plastic and steel bins as bulk storage structures to reduce maize post-harvest loss in Ejura, Ghana during the period from February 2016 to January 2017. Maize pre-disinfested with a solar biomass hybrid dryer was stored in the following treatments: i. a white 7-ton plastic bin filled with untreated maize, ii. agreen 7-ton plastic bin filled with untreated maize, iii.a 6-ton Kikapu steel bin filled with untreated maize, iv. six 50-kg polypropylene (PP) bags filled with maize treated with Betallic Super (80 g pirimiphos-methyl and 15 g permethrin per liter as an emulsifiable concentrate (EC)), and v. six 50-kg PP bags filled with untreated maize ascontrol. Moisture content, insect pests, insect damaged kernels (IDK), grain weight loss, aflatoxin and fumonisin levels data were collected monthly. Sitophilus zeamais, Tribolium castaneum, Cathartus quadricollis, and Cryptolestes ferrugineus were the dominant insect species collected from maize samples. At the end of 12 months of storage, % IDK in the control was >17% while IDK values in the other treatments were <3%. Mean grain weight losses of <1% were recorded in the bin treatments. Mycotoxin levels in the control were above the allowable threshold of 15 ppb. Our data suggest that use of plastic and steel bins has potential to reduce post-harvest loss of maize during storage
Traditional knowledge on Nicobari aloo (Dioscorea alata L.) among Nicobaritribal community of Car Nicobar Island, India
Nicobarese, the dominant tribe of Andaman and Nicobar Islands, rely on coconut-based cropping systems and fishingfor livelihood. The Nicobari aloo (Dioscorea alata) is valued staple food crop for the community. Diverse types ofDioscorea alata are conserved in different parts of the islands. The acquired knowledge on this food crop over thegenerations is vital for the sustenance. The Nicobarese live in joint family system called “Tuhet” which share land, coconutpalms, tuber crops and livestock. Each tuhet cultivates different varieties of Nicobari aloo along with other crops. It wasobserved and documented that this tribe cultivate Nicobari aloo in traditional way even at present, as natural/organic farmingpractices without using fertilisers and chemicals. The community makes away of preparations of Nicobari aloo tubers forregular consumption as well as during village festivals. This paper documents the traditional knowledge of the tribe on thistuber species, varieties, cultivation and utilisation
The twilight of the Liberal Social Contract? On the Reception of Rawlsian Political Liberalism
This chapter discusses the Rawlsian project of public reason, or public justification-based 'political' liberalism, and its reception. After a brief philosophical rather than philological reconstruction of the project, the chapter revolves around a distinction between idealist and realist responses to it. Focusing on political liberalism’s critical reception illuminates an overarching question: was Rawls’s revival of a contractualist approach to liberal legitimacy a fruitful move for liberalism and/or the social contract tradition? The last section contains a largely negative answer to that question. Nonetheless the chapter's conclusion shows that the research programme of political liberalism provided and continues to provide illuminating insights into the limitations of liberal contractualism, especially under conditions of persistent and radical diversity. The programme is, however, less receptive to challenges to do with the relative decline of the power of modern states
Religious Reasons for Campbell's View of Emotional Appeals in Philosophy of Rhetoric
This is the author's accepted manuscript.Reading Campbell's Philosophy of Rhetoric from a rhetorical perspective--as an attempt to address issues relevant to religious rhetoric--I argue that Campbell's aims of preparing future ministers to preach and defending the authority of revealed religion shaped, first, his conception of inventing and presenting emotional appeals and, second, his key assumptions about reason and passion. The essay adds a chapter to accounts of the relationship between reason and passion in sacred rhetorics and in rhetorical traditions more generally, and addresses the question of what Campbell's theory of rhetoric may aim to inculcate or cultivate emotionally and why
STIM2 regulates PKA-dependent phosphorylation and trafficking of AMPARs
STIMs (STIM1 and STIM2 in mammals) are transmembrane proteins that reside in the endoplasmic reticulum (ER) and regulate store-operated Ca2+ entry (SOCE). The function of STIMs in the brain is only beginning to be explored, and the relevance of SOCE in nerve cells is being debated. Here we identify STIM2 as a central organizer of excitatory synapses. STIM2, but not its paralogue STIM1, influences the formation of dendritic spines and shapes basal synaptic transmission in excitatory neurons. We further demonstrate that STIM2 is essential for cAMP/PKA-dependent phosphorylation of the AMPA receptor (AMPAR) subunit GluA1. cAMP triggers rapid migration of STIM2 to ER–plasma membrane (PM) contact sites, enhances recruitment of GluA1 to these ER-PM junctions, and promotes localization of STIM2 in dendritic spines. Both biochemical and imaging data suggest that STIM2 regulates GluA1 phosphorylation by coupling PKA to the AMPAR in a SOCE-independent manner. Consistent with a central role of STIM2 in regulating AMPAR phosphorylation, STIM2 promotes cAMP-dependent surface delivery of GluA1 through combined effects on exocytosis and endocytosis. Collectively our results point to a unique mechanism of synaptic plasticity driven by dynamic assembly of a STIM2 signaling complex at ER-PM contact sites
Quantifying the Effects of Elastic Collisions and Non-Covalent Binding on Glutamate Receptor Trafficking in the Post-Synaptic Density
One mechanism of information storage in neurons is believed to be determined by the strength of synaptic contacts. The strength of an excitatory synapse is partially due to the concentration of a particular type of ionotropic glutamate receptor (AMPAR) in the post-synaptic density (PSD). AMPAR concentration in the PSD has to be plastic, to allow the storage of new memories; but it also has to be stable to preserve important information. Although much is known about the molecular identity of synapses, the biophysical mechanisms by which AMPAR can enter, leave and remain in the synapse are unclear. We used Monte Carlo simulations to determine the influence of PSD structure and activity in maintaining homeostatic concentrations of AMPARs in the synapse. We found that, the high concentration and excluded volume caused by PSD molecules result in molecular crowding. Diffusion of AMPAR in the PSD under such conditions is anomalous. Anomalous diffusion of AMPAR results in retention of these receptors inside the PSD for periods ranging from minutes to several hours in the absence of strong binding of receptors to PSD molecules. Trapping of receptors in the PSD by crowding effects was very sensitive to the concentration of PSD molecules, showing a switch-like behavior for retention of receptors. Non-covalent binding of AMPAR to anchored PSD molecules allowed the synapse to become well-mixed, resulting in normal diffusion of AMPAR. Binding also allowed the exchange of receptors in and out of the PSD. We propose that molecular crowding is an important biophysical mechanism to maintain homeostatic synaptic concentrations of AMPARs in the PSD without the need of energetically expensive biochemical reactions. In this context, binding of AMPAR with PSD molecules could collaborate with crowding to maintain synaptic homeostasis but could also allow synaptic plasticity by increasing the exchange of these receptors with the surrounding extra-synaptic membrane
Genome-wide analysis identifies 12 loci influencing human reproductive behavior.
The genetic architecture of human reproductive behavior-age at first birth (AFB) and number of children ever born (NEB)-has a strong relationship with fitness, human development, infertility and risk of neuropsychiatric disorders. However, very few genetic loci have been identified, and the underlying mechanisms of AFB and NEB are poorly understood. We report a large genome-wide association study of both sexes including 251,151 individuals for AFB and 343,072 individuals for NEB. We identified 12 independent loci that are significantly associated with AFB and/or NEB in a SNP-based genome-wide association study and 4 additional loci associated in a gene-based effort. These loci harbor genes that are likely to have a role, either directly or by affecting non-local gene expression, in human reproduction and infertility, thereby increasing understanding of these complex traits
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