947 research outputs found
Combinatorial Control through Allostery
Many instances of cellular signaling and transcriptional regulation involve
switch-like molecular responses to the presence or absence of input ligands. To
understand how these responses come about and how they can be harnessed, we
develop a statistical mechanical model to characterize the types of Boolean
logic that can arise from allosteric molecules following the
Monod-Wyman-Changeux (MWC) model. Building upon previous work, we show how an
allosteric molecule regulated by two inputs can elicit AND, OR, NAND and NOR
responses, but is unable to realize XOR or XNOR gates. Next, we demonstrate the
ability of an MWC molecule to perform ratiometric sensing - a response behavior
where activity depends monotonically on the ratio of ligand concentrations. We
then extend our analysis to more general schemes of combinatorial control
involving either additional binding sites for the two ligands or an additional
third ligand and show how these additions can cause a switch in the logic
behavior of the molecule. Overall, our results demonstrate the wide variety of
control schemes that biological systems can implement using simple mechanisms
The Effects of Different Wavelengths of Light on Tribolium castaneum
Citation: Pfannenstiel, L. (2017). The Effects of Different Wavelengths of Light on Tribolium castaneum . 1st Annual Undergraduate Research Experience in Entomology Symposium, November 16, 2016. Manhattam, KS.Insects are known to be able to see different wavelengths of lights than humans can see. Because of this, there has been a lot of research done into using light to prevent damage caused by storedproduct pests. Common pests that research has been performed on are psocids (Diaz-Montano et al., 2015) and fruit flies (Saranwong et al., 2011). One of the biggest pests of stored-products is the red flour beetle Tribolium castaneum. Research on the attraction of different wavelengths of light has already been done on these beetles and published (Duehl et al., 2011), and my project mirrors that research. My hypothesis was that the shorter wavelengths of light would attract red flour beetles while the longer wavelengths of light would have no effect. My results show that, compared to a white light, the shorter wavelength light attracted more beetles. Compared to no light, there wasn’t a definite trend in wavelength of lights and attractiveness. The attractiveness of short-wavelength lights could be used to make traps for red flour beetles more effective and prevent damage to storedgrains
Tunnel Damage Resulting from Seismic Loading
Correlation of ground motion to observed tunnel damage has largely been based on estimates of ground motion rather than observations and measurements. In an effort to provide a data set that included both measured ground motions and documented tunnel response, an experiment was designed and fielded 0.5 km from a recent underground nuclear explosion (UNE) which had a body wave magnitude, mb, and a Richter local magnitude, ML, of 5.0. The data obtained in this experiment are summarized in the paper. The discussion centers on the applicability of the results of this experiment to the design of underground facilities for a proposed high-level nuclear waste repository at Yucca Mountain, Nevada
Could a Mid-Level Dental Provider Increase Access to Oral Health Care in Michigan?
According to a 2000 Surgeon General’s report, the United States faces an epidemic of unmet oral health needs, the result of both the high cost of care and geographic maldistribution of providers. This article assesses the extent of this unmet health care needs in Michigan, and examines one possible solution: the introduction of a mid-level dental provider (MDP) who could provide preventive and basic restorative care, under the supervision of a Michigan dentist. MDPs in various forms currently practice in over 50 countries including Canada and the U.K. The evidence suggests that a large and rigorous pilot of mid-level dental providers should be undertaken in Michigan, to inform policymakers about the structure’s potential for improving access to oral health care for vulnerable populations in the state
Influence of variable decoupling between vertically separated fault populations on structural inheritance – The Laminaria High, NW Shelf of Australia
When extension events are greatly separated in time, older faults may be buried and stratigraphically separated from newly developing faults at shallower depths. During rifting, the buried structures may reactivate and propagate upwards to be expressed within the shallow system. The degree of linkage between structural levels determines the influence that the deeper structures can exert over the geometry and evolution of the incipient fault system. In this study we use 3D seismic reflection data to examine how a deep fault population across the Laminaria High, NW shelf of Australia influences the development of a younger fault system at shallow depths. These fault populations are non-parallel and decoupled across a mechanically weak interval. The majority of shallow faults are not linked to those at depth. However, the reactivation and upward propagation of some of the deeper faults produce anomalously oriented structures at shallow depths, hard-linked to the deeper structures. One fault in particular shows along-strike variability, with the deep segment reactivated and present at shallow depths in the west. To the east, the shallow and deep fault segments become decoupled across the mechanically weak interval, although some soft-linkage and strain transfer still occurs. We suggest that this switch in the degree of coupling along the fault is due to the geometry of the deeper structure, with the transition corresponding to a prominent relay ramp. We show how the geometry of a deeper fault may affect its propensity to reactivate during subsequent extensional events, ultimately affecting the degree of structural inheritance that is expressed within younger, shallower fault populations
Unemployment Insurance and Low-Educated Single Working Mothers Before and After Welfare Reform
Survey of Trogoderma species (Coleoptera: Dermestidae) associated with international trade of dried distiller’s grains and solubles in the USA: Presentation
Dried distiller’s grains and solubles, DDGS, is a valuable commodity with substantial international trade. Vietnam discovered an infestation of Trogoderma inclusum, an actionable quarantine pest, in DDGS from the USA in 2012. All subsequent shipments to Vietnam were required to be fumigated. A shipment to Vietnam from the USA 2015 was then discovered with T. variabile. We surveyed the presence and activity of T. inclusum and T. variabile at locations in the USA that provide DDGSs for shipment to Vietnam. Seven facilities in four states that either produced DDGSs or that facilitated bulk shipments were studied. Pheromone traps were deployed at each location and monitored for several weeks. T. variaible was trapped at all seven sites while T. inclusum was trapped at just five of these. T. variabile were captured in nearly every trapping period and at higher numbers than T. inclusum at five locations, while two locations captured more T. inclusum than T. variabile. Spatial variation seemed to occur within each site, but there was no common pattern among facilities. Substantial numbers of beetles were caught in the outdoor sticky flight traps for most locations, except for relatively low flight trap numbers at locations 1, 4 and 6. The results show that T. variabile and T. inclusum are commonly associated with DDGSs produced in the USA, that these beetles could infest product being shipped overseas, and provide information that can be used to develop risk assessment and pest management programs for the future.Dried distiller’s grains and solubles, DDGS, is a valuable commodity with substantial international trade. Vietnam discovered an infestation of Trogoderma inclusum, an actionable quarantine pest, in DDGS from the USA in 2012. All subsequent shipments to Vietnam were required to be fumigated. A shipment to Vietnam from the USA 2015 was then discovered with T. variabile. We surveyed the presence and activity of T. inclusum and T. variabile at locations in the USA that provide DDGSs for shipment to Vietnam. Seven facilities in four states that either produced DDGSs or that facilitated bulk shipments were studied. Pheromone traps were deployed at each location and monitored for several weeks. T. variaible was trapped at all seven sites while T. inclusum was trapped at just five of these. T. variabile were captured in nearly every trapping period and at higher numbers than T. inclusum at five locations, while two locations captured more T. inclusum than T. variabile. Spatial variation seemed to occur within each site, but there was no common pattern among facilities. Substantial numbers of beetles were caught in the outdoor sticky flight traps for most locations, except for relatively low flight trap numbers at locations 1, 4 and 6. The results show that T. variabile and T. inclusum are commonly associated with DDGSs produced in the USA, that these beetles could infest product being shipped overseas, and provide information that can be used to develop risk assessment and pest management programs for the future
Unemployment Insurance and Low-Educated Single Working Mothers Before and After Welfare Reform
The Future of ISIS and US Counterterrorism: A Study of ISIS, Boko Haram, Al-Shabaab, and the US Policy Response
This study is comprised of two parts. Part 1 focuses on ISIS, Boko Haram, and Al-Shabaab, examining the structures, tactics, and motivations of the groups. Each group seeks territory in its respective region. After losing territories, Boko Haram and Al-Shabaab both turned to guerilla attacks and suicide bombing, destabilizing the areas formerly under their control. Having lost much territory, ISIS is already showing signs of behaving more like an insurgency and employing tactics similar to Boko Haram and Al-Shabaab by resorting to attacks on soft targets as it continues to be deprived of territory. Part 2 focuses on the US policy response to ISIS, Boko Haram, and Al-Shabaab. After describing the Obama Administration’s objectives, polices, and results against these groups, this study concludes that while President Obama’s objectives were met fairly well and the groups were weakened in territorial capacity, the groups continue to thrive in certain capacities and the administration failed to deter the groups’ escalating soft target attacks. In detailing and speculating upon the Trump Administration’s policies towards ISIS, Boko Haram, and Al-Shabaab, this study predicts the Trump Administration’s potential departures from the previous administration and highlights the opportunities and challenges confronting President Trump in countering the groups. This study finds that the Trump Administration will likely increase US troop levels in the fights against ISIS, Boko Haram, and Al-Shabaab, and that sustaining gains against the groups will necessitate a long-term US role of security and surveillance in areas vulnerable to the groups’ attacks
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