2,842 research outputs found
Effects of pumping on entomopathogenic nematodes and temperature increase within a spray system
Exposure to hydrodynamic stresses and increased temperature during hydraulic agitation within a spray system could cause permanent damage to biological pesticides during spray application. Damage to a benchmark biopesticide, entomopathogenic nematodes (EPNs), was measured after a single passage through three different pump types (centrifugal, diaphragm, and roller) at operating pressures up to 828 kPa. No mechanical damage to the EPNs due to passage through the pumps was observed. Separate tests evaluated the effect of pump recirculation on temperature increase of water within a laboratory spray system (56.8-L spray tank) and a conventional-scale spray system (1136-L spray tank). A constant volume of water (45.4 L) was recirculated through each pump at 15.1 L/min within the laboratory spray system. After 2 h, the temperature increase for the centrifugal pump was 33.6 degrees C, and for the diaphragm and roller pumps was 8.5 degrees C and 11.2 degrees C, respectively. The centrifugal pump was also evaluated within the conventional spray system, under both a constant (757 L) and reducing volume scenario, resulting in an average temperature increase of 3.2 degrees C and 6.5 degrees C, respectively, during the 3-h test period. When comparing the number of recirculations for each test, the rate of temperature increase was the same for the conventional spray, system (for both the constant and reducing volume scenarios), while for the laboratory spray system the temperature increased at a greater rate, suggesting that the volume capacity of the spray tank is the primary factor influencing the temperature increase. Results from this study indicate that thermal influences during pump recirculation could be more detrimental to EPNs than mechanical stress. Results show that extensive recirculation of the tank mix can cause considerable increases in the liquid temperature. Diaphragm and roller pumps (low-capacity pumps) are better suited for use with biopesticides compared to the centrifugal pump, which was found to contribute significant heat to the spray system
Communication in the Gig Economy: Buying and Selling in Online Freelance Marketplaces
The proliferating gig economy relies on online freelance marketplaces, which support relatively anonymous interactions by text-based messages. Informational asymmetries thus arise that can lead to exchange uncertainties between buyers and freelancers. Conventional marketing thought recommends reducing such uncertainty. However, uncertainty reduction and uncertainty management theories indicate that buyers and freelancers might benefit more from balancing, rather than reducing, uncertainty, such as by strategically adhering to or deviating from common principles. With dyadic analyses of calls for bids and bids from a leading online freelance marketplace, this study reveals that buyers attract more bids from freelancers when they provide moderate degrees of task information and concreteness, avoid sharing personal information, and limit the affective intensity of their communication. Freelancers’ bid success and price premiums increase when they mimic the degree of task information and affective intensity exhibited by buyers. However, mimicking a lack of personal information and concreteness reduces freelancers’ success, so freelancers should always be more concrete and offer more personal information than buyers do. These contingent perspectives offer insights into buyer–seller communication in two-sided online marketplaces; they clarify that despite, or sometimes due to, communication uncertainty, both sides can achieve success in the online gig economy
Long-Term Stability of an Area-Reversible Atom-Interferometer Sagnac Gyroscope
We report on a study of the long-term stability and absolute accuracy of an
atom interferometer gyroscope. This study included the implementation of an
electro-optical technique to reverse the vector area of the interferometer for
reduced systematics and a careful study of systematic phase shifts. Our data
strongly suggests that drifts less than 96 deg/hr are possible after
empirically removing shifts due to measured changes in temperature, laser
intensity, and several other experimental parameters.Comment: 4 pages, 4 figures, submitted to PR
Recommended from our members
History of Entomopathogenic Nematology
The history of entomopathogenic nematology is briefly reviewed. Topic selections include early descriptions of members
of Steinernema and Heterorhabditis, how only morphology was originally used to distinguish between the species; descriptions of the
symbiotic bacteria and elucidating their role in the nematode- insect complex, including antibiotic properties, phase variants, and
impeding host defense responses. Other topics include early solutions regarding production, storage, field applications and the first
commercial sales of entomopathogenic nematodes in North America. Later studies centered on how the nematodes locate insect
hosts, their effects on non-target organisms and susceptibility of the infective juveniles to soil microbes. While the goals of early
workers was to increase the efficacy of entomopathogenic nematodes for pest control, the increasing use of Heterorhabditis and
Photorhabdus as genetic models in molecular biology is noted.Keywords: Heterorhabditis spp., Entomopathogenic nematodes, Steinernema spp., Histor
A Discrete Class of Intergenic DNA Dictates Meiotic DNA Break Hotspots in Fission Yeast
Meiotic recombination is initiated by DNA double-strand breaks (DSBs) made by Spo11 (Rec12 in fission yeast), which becomes covalently linked to the DSB ends. Like recombination events, DSBs occur at hotspots in the genome, but the genetic factors responsible for most hotspots have remained elusive. Here we describe in fission yeast the genome-wide distribution of meiosis-specific Rec12-DNA linkages, which closely parallel DSBs measured by conventional Southern blot hybridization. Prominent DSB hotspots are located ∼65 kb apart, separated by intervals with little or no detectable breakage. Most hotspots lie within exceptionally large intergenic regions. Thus, the chromosomal architecture responsible for hotspots in fission yeast is markedly different from that of budding yeast, in which DSB hotspots are much more closely spaced and, in many regions of the genome, occur at each promoter. Our analysis in fission yeast reveals a clearly identifiable chromosomal feature that can predict the majority of recombination hotspots across a whole genome and provides a basis for searching for the chromosomal features that dictate hotspots of meiotic recombination in other organisms, including humans
Exploring the impact of sleep on emotional and physical well-being in professional cricketers: a cohort study over an in-season training period
BackgroundProfessional athletes navigate a multitude of unique challenges associated to sport-specific factors (e.g., training, travel and competition) and non-sport factors (e.g., performance pressure, stress and anxiety) that can interfere with healthy sleep behaviors. Sleep plays a key role in proper biopsychosocial development as well as short- and long-term biological, physical, psychological, and cognitive health. As poor sleep quality is known to impair proper brain function, this study aimed to investigate the effect of sleep quality on a professional athlete's ability to train, recover, and perform, as well as their overall emotional and physical well-being.MethodsA cohort study was performed in 40 professional male cricket athletes from the Dutch national cricket team (mean age 26.5 ± 5.1 years). The athletes were monitored across a 22 weeks in-season training period. Sleep quality and overall emotional and physical well-being were assessed using daily sleep diaries and questionnaires which scored the readiness to train, stress levels, fatigue, muscle soreness and flu symptoms respectively. Quality of sleep and subsequent association with the consecutive elements of the well-being questionnaire were assessed through statistical using the student t-test and clinical differences with the methodology of Osoba and colleagues: <5% “no change”, 5%–10% “little change”; 10%–20% “moderate change”; and >20% “very much change”.ResultsThe results demonstrated that the professional athletes assessed their sleep quality as average with a mean score of 3.4 out of 5. Lower perceived quality of sleep (<75th percentile) was correlated with a decreased readiness to train (mean score 3.2 [IQR: 3.0–4.0] vs. 3.5 [IQR: 3.0–5.0]; P < 0.001) and increased extent of muscle soreness (2.7 [IQR: 2.0–3.0] vs. 2.3 [IQR: 2–3]; P < 0.001), stress level (mean score 2.3 [IQR: 2.0–3.0] vs. 1.9 [IQR: 1.0–2.0]; P < 0.001) and perceived fatigue (mean score 2.9 [IQR: 2.0–3.0] vs. 2.3 [IQR: 2.0–3.0]; P < 0.001). Likewise, in patients with lower perceived quality of sleep, the proportion of players presenting with flu symptoms increased over 4-fold (4.1% vs. 17%; P < 0.001).ConclusionsThis study highlights that good sleep quality positively influences the overall emotional and physical well-being of professional athletes. Our results emphasize the importance of targeted sleep interventions to improve sleep quality and subsequently optimize psychological and physiological wellness
Resistance to wheat rusts identified in wheat/Amblyopyrum muticum chromosome introgressions
© 2020 The Authors. Crop Science © 2020 Crop Science Society of America Wheat (Triticum aestivum L.) rusts are a worldwide production problem. Plant breeders have used genetic resistance to combat these fungi. However, single-gene resistance is rapidly overcome as a result of frequent occurrence of new virulent fungal strains. Thus, a supply of new resistance sources is continually needed, and new resistance sources are limited within hexaploid wheat genetic stocks. Wild relatives are able to be a resource for new resistance genes but are hindered because of chromosome incapability with domesticated wheats. Twenty-eight double-haploid hexaploid wheat/Amblyopyrum muticum (Boiss.) Eig introgression lines, with introgressions covering the majority of the T genome, were evaluated for resistance to Puccinia triticina Erikss., P. graminis Pers.:Pers. f.sp. tritici Erikss. & E. Henning, and P. striiformis Westend. f.sp. tritici Erikss. At the seedling level, four lines were resistant to races of P. triticina, six lines were resistant to P. graminis, and 15 lines were resistant to P. striiformis. At the adult stage, 16 lines were resistant to P. triticina. Line 355 had resistance to all three rusts and line 161 had resistance to all tested races of P. triticina. Some of these lines will require further work to reduce the size of the introgressed segment; however, lines 92 and 355 have very small fragments and can be used directly as new resistance donors
The South Asian genome
Genetics of disease
Microarrays
Variant genotypes
Population genetics
Sequence alignment
AllelesThe genetic sequence variation of people from the Indian subcontinent who comprise one-quarter of the world's population, is not well described. We carried out whole genome sequencing of 168 South Asians, along with whole-exome sequencing of 147 South Asians to provide deeper characterisation of coding regions. We identify 12,962,155 autosomal sequence variants, including 2,946,861 new SNPs and 312,738 novel indels. This catalogue of SNPs and indels amongst South Asians provides the first comprehensive map of genetic variation in this major human population, and reveals evidence for selective pressures on genes involved in skin biology, metabolism, infection and immunity. Our results will accelerate the search for the genetic variants underlying susceptibility to disorders such as type-2 diabetes and cardiovascular disease which are highly prevalent amongst South Asians.Whole genome sequencing to discover genetic variants underlying type-2 diabetes, coronary heart disease and related phenotypes amongst Indian Asians. Imperial College Healthcare NHS Trust cBRC 2011-13 (JS Kooner [PI], JC Chambers)
An Annotated Bibliography of Pigeonpea Diseases 1906 - 81
This bibliography has been published to provide annotated information about
selected publications concerning pigeonpea diseases in retrospective support of
the abstracts published since 1982 in the International Pigeonpea Newsletter (also
published by ICRISAT).
This compilation is not comprehensive, but it lists the more important documents
of which the authors have become aware during their work at ICRISAT Center and
elsewhere. For fuller information readers should consult information available from
the Commonwealth Agricultural Bureaux (e.g., via the internationally accessible
Dialog data base) or from FAO (via the AGRIS data base).
Language abbreviations used in the citations are as follows:
De = German Es = Spanish Fr = French
It = Italian Pt = Portuguese
The authors gratefully acknowledge assistance given in the compilation of
this bibliography by R. Narsing Rao, S. Prasannalakshmi, S. Varma, J.B. Wills,
and N. Raghavan
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