INFORMATION SEEKING BEHAVIOR: THE EFFECTS OF RELATIONALISM ON THE SELECTION OF INFORMATION SOURCES

In a world where \u27Google\u27 is a verb, this research asks the question \u27what influences an individual\u27s decision to select one information source over another?\u27 Previous works have discussed relational versus nonrelational information sources (Rulke, Zaheer, & Anderson, 2000). Other research focuses on the information quality (O\u27Reilly, 1982), source accessibility (Culnan, 1984, 1985), or source richness (Daft, Lengel, & Trevino, 1987; Daft & Macintosh, 1981) but all these prior works do not address the social aspects of information sources. This research defines and develops the construct of relationalism which is reflective of the social aspects of information sources. An important argument put forth in this work is that individuals will interact differently with a source based on its relationalism. Communication literature suggests that an individual will respond socially to another\u27s social invitation even if the \u27other\u27 is actually an inanimate object (Nass & Moon, 2000). For example, individuals responded to social cues given by a robot no differently than the same social cues from a three-year-old child. To investigate source selection this research uses two experiments and a survey. The experimental approach allows for a high level of control over the task design and other extraneous influences. The survey methodology utilizes knowledge workers in business organizations, and examines the profiles of sources used in a realistic work setting. While the experimental design improves the internal validity of the model, the survey approach allows for a superior assessment of the external validity. Such methodological triangulation provides for a robust testing of the model and greater confidence in its emerging prescriptions. The first experiment investigates the antecedents to relationalism. Objective design characteristics were found to be positively related to relationalism. Furthermore a socially oriented factor was also related to relationalism. The second experiment investigated the relationship between relationalism and source selection. This experiment also included task effects and controlled for personality variables. The relationship between relationalism and source selection depended on the nature of the task with more complex tasks indicating a stronger preference for higher relationalism sources. The findings from the survey of knowledge workers largely corroborated the findings from the experiments though some differences were seen. From the experimental and survey results implications for research and practice are developed. Further this research contributes to a deeper understanding of information source selection in a modern IT-enabled environment

A Review of Invasive Plant Management in Special Ecological Areas, Hawai‘i Volcanoes National Park, 1984-2007

Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.In Hawai‘i Volcanoes National Park (134,852 ha), management units called Special Ecological Areas (SEAs) were established to control 20+ highly disruptive invasive plant species perceived to be too widespread for parkwide eradication to be feasible. Instead control efforts were focused on excluding target weeds from high value areas. Between 1984 and 1986 the first six SEAs and a buffer unit (total area >5,000 ha) were established in wet ‘ōhi‘a/hapu‘u (Metrosideros polymorpha/Cibotium glaucum) forest, mesic koa (Acacia koa) forest, and seasonally dry ‘ōhi‘a communities (Tunison and Stone 1992). After initial treatment of weeds, crews revisited sites at one to five year return intervals to remove any new weeds that reestablished. Over the next two decades, additional funding was made available to increase the number and size of SEAs. By 2007, 27 SEAs and buffer units covering over 26,720 ha were managed to exclude target weeds. Control data of 10 SEAs for which we had the longest data sets were evaluated. From 1985 to 2007, control efforts in SEAs expanded from 5,045 ha to 26,687 ha, a 500% increase in area. In contrast, annual labor cost spent in the field increased only about 50% (adjusted to 2007 dollars). This translated to a three-fold decrease in labor costs per hectare ($28.96/ ha in 1985 to$8.61/ha in 2007) across all units. Additional cost savings were made by improving the efficiency in search and treatment methods (e.g. aerial spray rig, chemical treatment of kāhili ginger). In summary, long-term maintenance of SEAs was possible when initial weed infestations could be reduced to low levels; subsequent recruitment of new alien weeds was low; and work loads dropped significantly after initial control efforts. Weaknesses of the SEA approach were that follow-up treatment was required indefinitely, weed infestations could increase in surrounding unmanaged areas and reinvasion into units could become unmanageable especially for small SEAs. In the future, managers will be challenged to secure funding to address ongoing weed maintenance; and maximize program effectiveness (e.g. optimizing intervals between follow-up treatments, applying new search and control technology). Developing effective partnerships with the community and adjacent landowners to expand management areas, creating buffer zones that will reduce seed dispersal into SEAs, and reconfiguring or abandoning small or ineffective SEAs are among some of strategies that could assist the long-term sustainability of the SEA approach

PAg-NeRF: Towards fast and efficient end-to-end panoptic 3D representations for agricultural robotics

Precise scene understanding is key for most robot monitoring and intervention tasks in agriculture. In this work we present PAg-NeRF which is a novel NeRF-based system that enables 3D panoptic scene understanding. Our representation is trained using an image sequence with noisy robot odometry poses and automatic panoptic predictions with inconsistent IDs between frames. Despite this noisy input, our system is able to output scene geometry, photo-realistic renders and 3D consistent panoptic representations with consistent instance IDs. We evaluate this novel system in a very challenging horticultural scenario and in doing so demonstrate an end-to-end trainable system that can make use of noisy robot poses rather than precise poses that have to be pre-calculated. Compared to a baseline approach the peak signal to noise ratio is improved from 21.34dB to 23.37dB while the panoptic quality improves from 56.65% to 70.08%. Furthermore, our approach is faster and can be tuned to improve inference time by more than a factor of 2 while being memory efficient with approximately 12 times fewer parameters

Organizational network strengthening effects on antiretroviral therapy initiation and adherence

The WHO recommends antiretroviral therapy (ART) initiation immediately after HIV diagnosis. When HIV services are fragmented and poorly coordinated, initiation of ART can be delayed. MEASURE Evaluation conducted an organizational network intervention in Addis Ababa, Ethiopia, which increased referral network density and client satisfaction in the intervention versus control networks. The objective of our study was to extend the parent study by assessing effects of network density on the speed of ART initiation and adherence to ART. Measures of client-time since HIV diagnosis, use of ART, satisfaction with HIV-related services, and adherence were obtained from cross-sectional interviews with female service recipients with HIV/AIDS at baseline (T1, 402) and at 18-month follow-up (T2, 524) and compared between network sites. We used weighted least squares estimation with probit regression techniques in a structural equation modeling framework for analyses. On average at follow-up, clients in the intervention network were more likely to have quicker ART initiation, and were initiated on ART 15 days faster than clients in the control network. Moreover, quicker ART initiation was associated with higher adherence. A unit increase in speed of ART initiation was associated with 0.5 points increase in latent adherence score in the intervention group (ρ < .05). Satisfaction with care positively predicted adherence to ART. Network density had no direct effect on ART adherence. This quasi-experiment demonstrated that increased referral network density, through improved HIV client referrals, can enhance speed of ART initiation, resulting in improved adherence. © Society of Behavioral Medicine 2018

Towards More Precise Survey Photometry for PanSTARRS and LSST: Measuring Directly the Optical Transmission Spectrum of the Atmosphere

Motivated by the recognition that variation in the optical transmission of the atmosphere is probably the main limitation to the precision of ground-based CCD measurements of celestial fluxes, we review the physical processes that attenuate the passage of light through the Earth's atmosphere. The next generation of astronomical surveys, such as PanSTARRS and LSST, will greatly benefit from dedicated apparatus to obtain atmospheric transmission data that can be associated with each survey image. We review and compare various approaches to this measurement problem, including photometry, spectroscopy, and LIDAR. In conjunction with careful measurements of instrumental throughput, atmospheric transmission measurements should allow next-generation imaging surveys to produce photometry of unprecedented precision. Our primary concerns are the real-time determination of aerosol scattering and absorption by water along the line of sight, both of which can vary over the course of a night's observations.Comment: 41 pages, 14 figures. Accepted PAS

The evolution of multiple-insecticide resistance in UK populations of tomato leafminer, Tuta absoluta

BACKGROUND The tomato leafminer, Tuta absoluta, is an economically important pest of tomatoes in Europe, Africa, Asia and South America. In the UK this species is controlled using an integrated pest management (IPM) programme which incorporates the insecticides spinosad and chlorantraniliprole. In response to UK grower concerns of loss of efficacy of these compounds at certain sites, insecticide bioassays were performed on five populations collected from four commercial glasshouses and potential mechanisms of resistance investigated. RESULTS We observed high levels of resistance to spinosad in four of the strains, and in two of these tolerance to chlorantraniliprole. Selection of one of these strains with chlorantraniliprole rapidly resulted in a line exhibiting potent resistance to this compound. Sequencing of messenger RNA encoding the nicotinic acetylcholine receptor (nAChR) alpha 6 subunit, target of spinosad, revealed Ta alpha 6 transcripts in the spinosad-resistant strains that lack exon 4 and encode a highly truncated protein, or contain a triplet deletion in the predicted first transmembrane domain resulting in the loss of a highly conserved amino acid. Sequencing of the ryanodine receptor gene, encoding the target of diamide insecticides, of the chlorantraniliprole-selected line revealed an amino acid substitution (G4903V) that has been previously linked to diamide resistance in populations of T. absoluta in the Mediterranean and South America. CONCLUSION Taken together our results reveal emerging resistance in UK populations of T. absoluta to two of the most important insecticides used as part of IPM, with significant implications for the control of this species in the UK. (c) 2019 Society of Chemical IndustryThis work was funded by PhD studentship awards from the Agriculture and Horticulture Development Board (AHDB) (CP 162) and the Biotechnology and Biological Sciences Research Council (BBSRC) (grant number: 1096240). ER was supported by funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under the STomP project, grant agreement no. 219262 (ARIMNet)

Insecticide resistance mediated 1 by an exon skipping event

Many genes increase coding capacity by alternate exon usage. The gene encoding the insect nicotinic acetylcholine receptor (nAChR) a6 subunit, target of the bio-insecticide spinosad, is one example of this and expands protein diversity via alternative splicing of mutually exclusive exons. Here, we show that spinosad resistance in the tomato leaf miner, Tuta absoluta is associated with aberrant regulation of splicing of Taa6 resulting in a novel form of insecticide resistance mediated by exon skipping. Sequencing of the a6 subunit cDNA from spinosad selected and unselected strains of T. absoluta revealed all Taa6 transcripts of the selected strain were devoid of exon 3, with comparison of genomic DNA and mRNA revealing this is a result of exon skipping. Exon skipping cosegregated with spinosad resistance in survival bioassays, and functional characterization of this alteration using modified human nAChR a7, a model of insect a6, demonstrated that exon 3 is essential for receptor function and hence spinosad sensitivity. DNA and RNA sequencing analyses suggested that exon skipping did not result from genetic alterations in intronic or exonic cis-regulatory elements, but rather was associated with a single epigenetic modification downstream of exon 3a, and quantitative changes in the expression of trans-acting proteins that have known roles in the regulation of alternative splicing. Our results demonstrate that the intrinsic capacity of the a6 gene to generate transcript diversity via alternative splicing can be readily exploited during the evolution of resistance and identifies exon skipping as a molecular alteration conferring insecticide resistance

The RCK1 domain of the human BK_(Ca) channel transduces Ca^(2+) binding into structural rearrangements

Large-conductance voltage- and Ca^(2+)-activated K^+ (BK_(Ca)) channels play a fundamental role in cellular function by integrating information from their voltage and Ca2+ sensors to control membrane potential and Ca^(2+) homeostasis. The molecular mechanism of Ca^(2+)-dependent regulation of BKCa channels is unknown, but likely relies on the operation of two cytosolic domains, regulator of K^+ conductance (RCK)1 and RCK2. Using solution-based investigations, we demonstrate that the purified BK_(Ca) RCK1 domain adopts an α/β fold, binds Ca^(2+), and assembles into an octameric superstructure similar to prokaryotic RCK domains. Results from steady-state and time-resolved spectroscopy reveal Ca^(2+)-induced conformational changes in physiologically relevant [Ca^(2+)]. The neutralization of residues known to be involved in high-affinity Ca^(2+) sensing (D362 and D367) prevented Ca^(2+)-induced structural transitions in RCK1 but did not abolish Ca^(2+) binding. We provide evidence that the RCK1 domain is a high-affinity Ca^(2+) sensor that transduces Ca^(2+) binding into structural rearrangements, likely representing elementary steps in the Ca^(2+)-dependent activation of human BK_(Ca) channels

iPSC-Derived Dopamine Neurons Reveal Differences between Monozygotic Twins Discordant for Parkinson’s Disease

SummaryParkinson’s disease (PD) has been attributed to a combination of genetic and nongenetic factors. We studied a set of monozygotic twins harboring the heterozygous glucocerebrosidase mutation (GBA N370S) but clinically discordant for PD. We applied induced pluripotent stem cell (iPSC) technology for PD disease modeling using the twins’ fibroblasts to evaluate and dissect the genetic and nongenetic contributions. Utilizing fluorescence-activated cell sorting, we obtained a homogenous population of “footprint-free” iPSC-derived midbrain dopaminergic (mDA) neurons. The mDA neurons from both twins had ∼50% GBA enzymatic activity, ∼3-fold elevated α-synuclein protein levels, and a reduced capacity to synthesize and release dopamine. Interestingly, the affected twin’s neurons showed an even lower dopamine level, increased monoamine oxidase B (MAO-B) expression, and impaired intrinsic network activity. Overexpression of wild-type GBA and treatment with MAO-B inhibitors normalized α-synuclein and dopamine levels, suggesting a combination therapy for the affected twin