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Climate policy: hard problem, soft thinking
Climate change is more uncertain, more global, and more long-term than most issues facing humanity. This trifecta makes a policy response that encompasses scientific correctness, public awareness, economic efficiency, and governmental effectiveness particularly difficult. Economic and psychological instincts impede rational thought. Elected officials, who cater to and foster voters‘ misguided beliefs, compound the soft thinking that results. Beliefs must change before unequivocal symptoms appear and humanity experiences the climate-change equivalent of a life-altering heart attack. Sadly, it may well take dramatic loss to jolt the collective conscience toward serious action. In the long run, the only solution is a bottom-up demand leading to policies that appropriately price carbon and technological innovation, and that promote ethical shifts toward a world in which low-carbon, high-efficiency living is the norm. In the short term, however, popular will is unlikely to drive serious action on the issue. Policy makers can and must try to overcome inherent psychological barriers and create pockets of certainty that link benefits of climate policy to local, immediate payoffs. It will take high-level scientific and political leadership to redirect currently misguided market forces toward a positive outcome
Post-Meiotic Intra-Testicular Sperm Senescence in a Wild Vertebrate
There is growing interest in sperm senescence, both in its underlying mechanisms and evolutionary consequences, because
it can impact the evolution of numerous life history traits. Previous studies have documented various types of sperm
senescence, but evidence of post-meiotic intra-testicular sperm senescence in wild animals is lacking. To assess such
senescence, we studied within-season changes in sperm motility in the common toad (Bufo bufo), where males produce all
sperm prior to the breeding season. We found that males exposed to experimentally induced re-hibernation at the start of
the breeding season, that is to experimentally lowered metabolic rates, stored sperm of significantly higher motility than
males that were kept under seminatural conditions without females throughout the breeding season. This finding indicates
that re-hibernation slows normal rates of sperm ageing and constitutes the first evidence to our knowledge of post-meiotic
intra-testicular sperm senescence in a wild vertebrate. We also found that in males kept in seminatural conditions, sperm
motility was positively related to the number of matings a male achieved. Thus, our results suggest that post-meiotic intratesticular
sperm senescence does not have a genetically fixed rate and may be modulated by temperature and possibly by
mating opportunities
Making Non-Career Jobs Attractive to Younger Workers
As most hospitality industry managers in the U.S. are already aware, there is a growing and persistent shortage of labor available for service-sector, non-career jobs, the very jobs so vital to the industry. In most cases, recruitment efforts for these jobs are targeted toward younger workers, those under age 25. The authors explore issues regarding the attractiveness of non-career jobs in the eyes of young persons and suggest that, in addition to factors related to the job itself (pay, hours, type of work), the type of procedures used by employers to make selection decisions are equally influential. Recommendations are made concerning how hospitality employers with non-career positions to fill can maximize the chances of successfully staffing their organizations
Direct Measurement of 2D and 3D Interprecipitate Distance Distributions from Atom-Probe Tomographic Reconstructions
Edge-to-edge interprecipitate distance distributions are critical for
predicting precipitation strengthening of alloys and other physical phenomena.
A method to calculate this 3D distance and the 2D interplanar distance from
atom-probe tomographic data is presented. It is applied to nanometer-sized
Cu-rich precipitates in an Fe-1.7 at.% Cu alloy. Experimental interprecipitate
distance distributions are discussed
Dehydration, deamination and enzymatic repair of cytosine glycols from oxidized poly(dG-dC) and poly(dI-dC)
Cytosine glycols (5,6-dihydroxy-5,6-dihydrocytosine) are initial products of cytosine oxidation. Because these products are not stable, virtually all biological studies have focused on the stable oxidation products of cytosine, including 5-hydroxycytosine, uracil glycols and 5-hydroxyuracil. Previously, we reported that the lifetime of cytosine glycols was greatly enhanced in double-stranded DNA, thus implicating these products in DNA repair and mutagenesis. In the present work, cytosine and uracil glycols were generated in double-stranded alternating co-polymers by oxidation with KMnO4. The half-life of cytosine glycols in poly(dG-dC) was 6.5 h giving a ratio of dehydration to deamination of 5:1. At high substrate concentrations, the excision of cytosine glycols from poly(dG-dC) by purified endonuclease III was comparable to that of uracil glycols, whereas the excision of these substrates was 5-fold greater than that of 5-hydroxycytosine. Kinetic studies revealed that the Vmax was several fold higher for the excision of cytosine glycols compared to 5-hydroxycytosine. In contrast to cytosine glycols, uracil glycols did not undergo detectable dehydration to 5-hydroxyuracil. Replacing poly(dG-dC) for poly(dI-dC) gave similar results with respect to the lifetime and excision of cytosine glycols. This work demonstrates the formation of cytosine glycols in DNA and their removal by base excision repair
CEO Clarity
A key task for CEOs is to communicate with analysts and investors about their companies' past performance and prospects in quarterly earnings conference calls. Some CEOs speak fuzzily, frequently using words such as "approximately", "probably", and "maybe." Others rarely use such tentative words. That is, they speak clearly. We show that CEO clarity is a matter of personal style; it is not driven by fundamental uncertainty in the companies' business activity. Analysts and the stock market respond more strongly to earnings news conveyed by clear CEOs. Past performance does not explain the style of a newly appointed CEO. However, when a firm does appoint a more clear-talking CEO, Tobin's Q increases and analyst recommendations become more favorable. Overall, investors and analysts appear to value clear talk
Paths to Convergence: Stock Price Behavior After Donald Trump's Election
How do market prices adjust towards stability after a shock? Tracking individual stock prices following their dramatic shakeup after Donald Trump’s surprise election provides an answer. Prices moved overwhelmingly in the appropriate direction on the first post-election day, albeit much too little. Relative prices needed several daily iterations to converge. Three days of historically strong cross-sectional momentum were followed by a brief reversal. Prices then settled. Firm characteristics that explained first-day returns, such as corporate taxes and foreign revenues, accounted for most of the observed momentum. These findings support prominent theories of slow but predictable diffusion of information into prices
Performance Comparison of Wireless Sensor Network Standard Protocols in an Aerospace Environment: ISA100.11a and ZigBee
Wireless Sensor Networks (WSNs) can provide a substantial benefit in spacecraft systems, reducing launch weight and providing unprecedented flexibility by allowing instrumentation capabilities to grow and change over time. Achieving data transport reliability on par with that of wired systems, however, can prove extremely challenging in practice. Fortunately, much progress has been made in developing standard WSN radio protocols for applications from non-critical home automation to mission-critical industrial process control. The relative performances of candidate protocols must be compared in representative aerospace environments, however, to determine their suitability for spaceflight applications. In this paper, we will present the results of a rigorous laboratory analysis of the performance of two standards-based, low power, low data rate WSN protocols: ZigBee Pro and ISA100.11a. Both are based on IEEE 802.15.4 and augment that standard's specifications to build complete, multi-hop networking stacks. ZigBee Pro targets primarily the home and office automation markets, providing an ad-hoc protocol that is computationally lightweight and easy to implement in inexpensive system-on-a-chip components. As a result of this simplicity, however, ZigBee Pro can be susceptible to radio frequency (RF) interference. ISA100.11a, on the other hand, targets the industrial process control market, providing a robust, centrally-managed protocol capable of tolerating a significant amount of RF interference. To achieve these gains, a coordinated channel hopping mechanism is employed, which entails a greater computational complexity than ZigBee and requires more sophisticated and costly hardware. To guide future aerospace deployments, we must understand how well these standards relatively perform in analog environments under expected operating conditions. Specifically, we are interested in evaluating goodput -- application level throughput -- in a representative crewed environment in the presence of varying levels of 802.11g Wi-Fi traffic. To do so, we use the NASA Johnson Space Center Wireless Habitat Testbed (WHT), a metallic, habitation-sized module designed for co-existence testing of wireless systems. In its quiescent state, the sealed WHT provides an RF-quiet environment to which we can selectively add interfering systems; it also provides a realistic level of multi-path self-interference for systems under investigation. In our test, we deploy two representative five node networks, configured in a star topology with all nodes reporting directly to a WSN gateway. Each ZigBee network WSN node is built using a Texas Instruments (TI) CC2530 system-on-a-chip radio running TI's ZigBee Pro Z-stack. Each ISA100.11a network node is built using a Nivis VersaNode 210 system-on-a-chip radio. In both cases, radios interface with TI MSP430-F5438 microcontroller implementing a common test application. Interference is provided by a D-link 802.11g Wi-Fi router transporting traffic generated using the Iperf network testing tool. For the single-channel ZigBee network, effects of both direct and indirect Wi-Fi interference are evaluated. For the channel-hopping ISA100.11a network, effects of interference from multiple Wi-Fi routers configured in non-overlapping 802.11g channels are evaluated. Our results show that, in general, the more lightweight ZigBee network performs well at low interference levels, but performance degrades as interference increases. Conversely, the more complex and costly ISA100.11a network continues to perform well as Wi-Fi interference levels increase
The added value of online user-generated content in traditional methods for influenza surveillance
Abstract There has been considerable work in evaluating the efficacy of using online data for health surveillance. Often comparisons with baseline data involve various squared error and correlation metrics. While useful, these overlook a variety of other factors important to public health bodies considering the adoption of such methods. In this paper, a proposed surveillance system that incorporates models based on recent research efforts is evaluated in terms of its added value for influenza surveillance at Public Health England. The system comprises of two supervised learning approaches trained on influenza-like illness (ILI) rates provided by the Royal College of General Practitioners (RCGP) and produces ILI estimates using Twitter posts or Google search queries. RCGP ILI rates for different age groups and laboratory confirmed cases by influenza type are used to evaluate the models with a particular focus on predicting the onset, overall intensity, peak activity and duration of the 2015/16 influenza season. We show that the Twitter-based models perform poorly and hypothesise that this is mostly due to the sparsity of the data available and a limited training period. Conversely, the Google-based model provides accurate estimates with timeliness of approximately one week and has the potential to complement current surveillance systems
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