1,774 research outputs found

    Pothole Reporting System

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    The purpose of this project is to create a pothole detection device that can be attached to the underside of a commercial vehicle. Potholes cost motorists around 6.4 billion dollars annually, thus demonstrating the need for a system to aid with the detections and reporting of potholes. The four systems we needed to consider for the implementation of this project were the power system, the sensing system, the data processing system, and the reporting and logging system. Power pulled from the vehicle will enable the sensors and data processing module. The data processing module will analyze the readings from the sensors and output pothole data to the logging and reporting system. The logging and reporting system, located on an android mobile device, will store the pothole locations on a cloud server

    Sperm death and dumping in Drosophila

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    Mating with more than one male is the norm for females of many species. In addition to generating competition between the ejaculates of different males, multiple mating may allow females to bias sperm use. In Drosophila melanogaster, the last male to inseminate a female sires approximately 80% of subsequent progeny. Both sperm displacement, where resident sperm are removed from storage by the incoming ejaculate of the copulating male, and sperm incapacitation, where incoming seminal fluids supposedly interfere with resident sperm, have been implicated in this pattern of sperm use. But the idea of incapacitation is problematic because there are no known mechanisms by which an individual could damage rival sperm and not their own. Females also influence the process of sperm use, but exactly how is unclear. Here we show that seminal fluids do not kill rival sperm and that any 'incapacitation' is probably due to sperm ageing during sperm storage. We also show that females release stored sperm from the reproductive tract (sperm dumping) after copulation with a second male and that this requires neither incoming sperm nor seminal fluids. Instead, males may cause stored sperm to be dumped or females may differentially eject sperm from the previous mating

    Ownership-dependent mating tactics of minor males of the beetle Librodor japonicus (Nitidulidae) with intra-sexual dimorphism of mandibles

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    Intra-sexual dimorphism is found in the weapons of many male beetles. Different behavioral tactics to access females between major and minor males, which adopt fighting and alternative tactics, respectively, are thought to maintain the male dimorphism. In these species major males have enlarged weapons that they use in fights with rival males. Minor males also have small weapons in some of these species, and it is unclear why these males possess weapons. We examined the hypothesis that minor males might adopt a fighting tactic when their status was relatively high in comparison with that of other males (e.g., ownership of a territory). We observed the behavioral tactics of major and minor males of the beetle Librodor japonicus, whose males have a dimorphism of their mandibles. Major males fought for resources, whereas minor males adopted two status-dependent tactics, fighting and sneaking, to access females, depending on their ownership of a sap site. We suggest that ownership status-dependent mating tactics in minor males may maintain the intra-sexual dimorphism in this beetle.</p

    The Reputational Consequences of Failed Replications and Wrongness Admission among Scientists

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    Scientists are dedicating more attention to replication efforts. While the scientific utility of replications is unquestionable, the impact of failed replication efforts and the discussions surrounding them deserve more attention. Specifically, the debates about failed replications on social media have led to worry, in some scientists, regarding reputation. In order to gain data-informed insights into these issues, we collected data from 281 published scientists. We assessed whether scientists overestimate the negative reputational effects of a failed replication in a scenario-based study. Second, we assessed the reputational consequences of admitting wrongness (versus not) as an original scientist of an effect that has failed to replicate. Our data suggests that scientists overestimate the negative reputational impact of a hypothetical failed replication effort. We also show that admitting wrongness about a non-replicated finding is less harmful to one’s reputation than not admitting. Finally, we discovered a hint of evidence that feelings about the replication movement can be affected by whether replication efforts are aimed one’s own work versus the work of another. Given these findings, we then present potential ways forward in these discussions

    Why the fair innings argument is not persuasive

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    The fair innings argument (FIA) is frequently put forward as a justification for denying elderly patients treatment when they are in competition with younger patients and resources are scarce. In this paper I will examine some arguments that are used to support the FIA. My conclusion will be that they do not stand up to scrutiny and therefore, the FIA should not be used to justify the denial of treatment to elderly patients, or to support rationing of health care by age. There are six issues arising out of the FIA which are to be addressed. First, the implication that there is such a thing as a fair share of life. Second, whether it makes sense to talk of a fair share of resources in the context of health care and the FIA. Third, that 'fairness' is usually only mentioned with regard to the length of a person's life, and not to any other aspect of it. Fourth, if it is sensible to discuss the merits of the FIA without taking account of the 'all other things being equal' argument. Fifth, the difference between what is unfair and what is unfortunate. Finally, that it is tragic if a young person dies, but only unfortunate if an elderly person does

    Negative phenotypic and genetic associations between copulation duration and longevity in male seed beetles

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    Reproduction can be costly and is predicted to trade-off against other characters. However, while these trade-offs are well documented for females, there has been less focus on aspects of male reproduction. Furthermore, those studies that have looked at males typically only investigate phenotypic associations, with the underlying genetics often ignored. Here, we report on phenotypic and genetic trade-offs in male reproductive effort in the seed beetle, Callosobruchus maculatus. We find that the duration of a male's first copulation is negatively associated with subsequent male survival, phenotypically and genetically. Our results are consistent with life-history theory and suggest that like females, males trade-off reproductive effort against longevity

    Male Responses to Conspecific Advertisement Signals in the Field Cricket Gryllus rubens (Orthoptera: Gryllidae)

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    In many species males aggregate and produce long-range advertisement signals to attract conspecific females. The majority of the receivers of these signals are probably other males most of the time, and male responses to competitors' signals can structure the spatial and temporal organization of the breeding aggregation and affect male mating tactics. I quantified male responses to a conspecific advertisement stimulus repeatedly over three age classes in Gryllus rubens (Orthoptera: Gryllidae) in order to estimate the type and frequency of male responses to the broadcast stimulus and to determine the factors affecting them. Factors tested included body size, wing dimorphism, age, and intensity of the broadcast stimulus. Overall, males employed acoustic response more often than positive phonotactic response. As males aged, the frequency of positive phonotactic response decreased but that of the acoustic response increased. That is, males may use positive phonotaxis in the early stages of their adult lives, possibly to find suitable calling sites or parasitize calling males, and then later in life switch to acoustic responses in response to conspecific advertisement signals. Males with smaller body size more frequently exhibited acoustic responses. This study suggests that individual variation, more than any factors measured, is critical for age-dependent male responses to conspecific advertisement signals

    Cost-effectiveness of recommended nurse staffing levels for short-stay skilled nursing facility patients

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    BACKGROUND: Among patients in skilled nursing facilities for post-acute care, increased registered nurse, total licensed staff, and nurse assistant staffing is associated with a decreased rate of hospital transfer for selected diagnoses. However, the cost-effectiveness of increasing staffing to recommended levels is unknown. METHODS: Using a Markov cohort simulation, we estimated the incremental cost-effectiveness of recommended staffing versus median staffing in patients admitted to skilled nursing facilities for post-acute care. The outcomes of interest were life expectancy, quality-adjusted life expectancy, and incremental cost-effectiveness. RESULTS: The incremental cost-effectiveness of recommended staffing versus median staffing was $321,000 per discounted quality-adjusted life year gained. One-way sensitivity analyses demonstrated that the cost-effectiveness ratio was most sensitive to the likelihood of acute hospitalization from the nursing home. The cost-effectiveness ratio was also sensitive to the rapidity with which patients in the recommended staffing scenario recovered health-related quality of life as compared to the median staffing scenario. The cost-effectiveness ratio was not sensitive to other parameters. CONCLUSION: Adopting recommended nurse staffing for short-stay nursing home patients cannot be justified on the basis of decreased hospital transfer rates alone, except in facilities with high baseline hospital transfer rates. Increasing nurse staffing would be justified if health-related quality of life of nursing home patients improved substantially from greater nurse and nurse assistant presence
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