We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Medical care is predicated on ‘do no harm’, yet the urgency to find drugs and vaccines to treat or prevent COVID-19 has led to an extraordinary effort to develop and test new therapies. Whilst this is an essential cornerstone of a united global response to the COVID-19 pandemic, the absolute requirements for meticulous efficacy and safety data remain. This is especially pertinent to the needs of pregnant women; a group traditionally poorly represented in drug trials, yet a group at heightened risk of unintended adverse materno-fetal consequences due to the unique physiology of pregnancy and the life course implications of fetal or neonatal drug exposure. However, due to the complexities of drug trial participation when pregnant (be they vaccines or therapeutics for acute disease), many clinical drug trials will exclude them. Clinicians must determine the best course of drug treatment with a dearth of evidence from either clinical or preclinical studies, where at least in the short term they may be more focused on the outcome of the mother than of her offspring.
Tracing the flow of solid matter during an explosion requires a rugged tag that can be measured by a unique identifiable signature. Silica-covered semiconductor quantum dots (QDs) provide a unique and tunable photoluminescent signature that emits from within a sacrificial outer layer. Five types of silica-covered zinc sulfide QDs were synthesized and covalently bound to commercial luminescent powders. The combination of five dots and five powders enables a matrix of 25 unique tags. The tracers are shown to be tolerant of environments associated with chemical explosives and provides a unique tag to evaluate debris fields.
Development of high energy density solid-state batteries with Li metal anodes has been limited by uncontrollable growth of Li dendrites in liquid and solid electrolytes (SEs). This, in part, may be caused by a dearth of information about mechanical properties of Li, especially at the nano- and microlength scales and microstructures relevant to Li batteries. We investigate Li electrodeposited in a commercial LiCoO2/LiPON/Cu solid-state thin-film cell, grown in situ in a scanning electron microscope equipped with nanomechanical capabilities. Experiments demonstrate that Li was preferentially deposited at the LiPON/Cu interface along the valleys that mimic the domain boundaries of underlying LiCoO2 (cathode). Cryogenic electron microscopy analysis of electrodeposited Li revealed a single-crystalline microstructure, and in situ nanocompression experiments on nano-pillars with 360–759 nm diameters revealed their average Young's modulus to be 6.76 ± 2.88 GPa with an average yield stress of 16.0 ± 6.82 MPa, ~24x higher than what has been reported for bulk polycrystalline Li. We discuss mechanical deformation mechanisms, stiffness, and strength of nano-sized electrodeposited Li in the framework of its microstructure and dislocation-governed nanoscale plasticity of crystals, and place it in the parameter space of existing knowledge on small-scale Li mechanics. The enhanced strength of Li at small scales may explain why it can penetrate and fracture through much stiffer and harder SEs than theoretically predicted.
This study aimed to evaluate the nutritional value of pasta enriched with legume or wheat gluten proteins and dried at varying temperature. A total of four isonitrogenous experimental diets were produced using gluten powder/wheat semolina (6/94, g/g) pasta and faba bean flour/wheat semolina (35/65, g/g) pasta dried at either 55°C (GLT and FLT, respectively) or 90°C (FVHT and GVHT, respectively). Experimental diets were fed to ten 1-month-old Wistar rats (body weight=176 (sem 15) g) for 21 d. Growth and nutritional, metabolic and inflammatory markers were measured and compared with an isonitrogenous casein diet (CD). The enrichment with faba bean increased the lysine, threonine and branched amino acids by 97, 23 and 10 %, respectively. Protein utilisation also increased by 75 % (P<0·01) in FLT in comparison to GLT diet, without any effect on the corrected faecal digestibility (P>0·05). Faba bean pasta diets' corrected protein digestibility and utilisation was only 3·5 and 9 %, respectively, lower than the CD. Growth rate, blood composition and muscle weights were not generally different with faba bean pasta diets compared with CD. Corrected protein digestibility was 3 % lower in GVHT than GLT, which may be associated with greater carboxymethyllysine. This study in growing rats clearly indicates improvement in growth performance of rats fed legume-enriched pasta diet compared with rats fed gluten–wheat pasta diet, regardless of pasta drying temperature. This means faba bean flour can be used to improve the protein quality and quantity of pasta.
By
Randall Berry, Department of Electrical Engineering and Computer Science, Northwestern University,
Michael L. Honig, Department of Electrical Engineering and Computer Science, Northwestern University,
Rakesh V. Vohra, Department of Economics, University of Pennsylvania
The continued growth of wireless networks and services depends on the availability of adequate spectrum resources. Accelerating demand for those resources, due to the popularity of portable data-intensive wireless devices, are testing the limits of current commercial wireless networks, underscoring the need for changes in current spectrum allocations. This has prompted the Federal Communications Commission (FCC) in the United States to consider ways to increase the supply of spectrum allocated to broadband access and to introduce techniques for improving the utilization of existing allocations [1, Ch. 5].
Spectrum allocations generally fall into one of two categories: a licensed allocation gives exclusive use rights to the licensee, whereas an unlicensed allocation corresponds to the commons model in which the band can be shared by different applications and service providers [2]. Licensed spectrum typically carries restrictions on how it can be used, and is generally not transferable. Although these restrictions have been alleviated to some extent by the introduction of secondary spectrum markets [3], existing rules still inhibit the reallocation of spectrum to more efficient uses.
In contrast to the current “command and control” method for licensing spectrum, a spectrum market is based on a notion of spectrum property rights, which can be traded among buyers and sellers. The potential benefits of spectrum markets for increasing the efficiency of spectrum allocations is widely acknowledged. Thus far related discussions have focused on secondary markets, which allow service providers with licensed spectrum to lease their spectrum to other service providers. Transactions must be filed with the FCC for approval (which are automatic in some scenarios), introducing delays that increase transaction costs [3].
Here we reconsider the spectrum allocation problem without existing regulatory constraints. We start by providing general motivations for introducing spectrum markets. That is, a basic policy choice is whether to define and enforce spectrum property rights. From a social welfare point of view, this choice ultimately depends on whether spectrum is scarce, that is, if demand for it exceeds supply when it is free.
Military personnel generally under-consume n-3 fatty acids and overconsume n-6 fatty acids. In a placebo-controlled, double-blinded study, we investigated whether a diet suitable for implementation in military dining facilities and civilian cafeterias could benefit n-3/n-6 fatty acid status of consumers. Three volunteer groups were provided different diets for 10 weeks. Control (CON) participants consumed meals from the US Military’s Standard Garrison Dining Facility Menu. Experimental, moderate (EXP-Mod) and experimental-high (EXP-High) participants consumed the same meals, but high n-6 fatty acid and low n-3 fatty acid containing chicken, egg, oils and food ingredients were replaced with products having less n-6 fatty acids and more n-3 fatty acids. The EXP-High participants also consumed smoothies containing 1000 mg n-3 fatty acids per serving, whereas other participants received placebo smoothies. Plasma and erythrocyte EPA and DHA in CON group remained unchanged throughout, whereas EPA, DHA and Omega-3 Index increased in EXP-Mod and EXP-High groups, and were higher than in CON group after 5 weeks. After 10 weeks, Omega-3 Index in EXP-High group had increased further. No participants exhibited changes in fasting plasma TAG, total cholesterol, LDL, HDL, mood or emotional reactivity. Replacing high linoleic acid (LA) containing foods in dining facility menus with similar high oleic acid/low LA and high n-3 fatty acid foods can improve n-6/n-3 blood fatty acid status after 5 weeks. The diets were well accepted and suitable for implementation in group feeding settings like military dining facilities and civilian cafeterias.
Theory suggests that early experiences may calibrate the “threshold activity” of the hypothalamus–pituitary–adrenal axis in childhood. Particularly challenging or particularly supportive environments are posited to manifest in heightened physiological sensitivity to context. Using longitudinal data from the Family Life Project (N = 1,292), we tested whether links between maternal sensitivity and hypothalamus–pituitary–adrenal axis activity aligned with these predictions. Specifically, we tested whether the magnitude of the within-person relation between maternal sensitivity and children's cortisol levels, a proxy for physiological sensitivity to context, was especially pronounced for children who typically experienced particularly low or high levels of maternal sensitivity over time. Our results were consistent with these hypotheses. Between children, lower levels of mean maternal sensitivity (7–24 months) were associated with higher mean cortisol levels across this period (measured as a basal sample collected at each visit). However, the magnitude and direction of the within-person relation was contingent on children's average levels of maternal sensitivity over time. Increases in maternal sensitivity were associated with contemporaneous cortisol decreases for children with typically low-sensitive mothers, whereas sensitivity increases were associated with cortisol increases for children with typically high-sensitive mothers. No within-child effects were evident at moderate levels of maternal sensitivity.
U.S. states have led the federal government in instituting policies aimed at promoting renewable energy. Nearly all research on renewable portfolio standards (RPSs) has treated RPS adoption as a binary choice. Given the substantial variation in the renewable energy goals established by RPSs, we propose a new measure of RPS ambition that accounts for the amount of additional renewable energy production needed to reach the RPS goal and the number of years allotted to reach the standard. By measuring RPS policy with more precision, our analysis demonstrates that many factors found to affect whether a state will adopt an RPS do not exert a similar effect on the policy’s ambitiousness. Most notably, our analysis demonstrates that Democratic control of the state legislature is the most consequential factor in determining the ambitiousness of state RPS policies.
Here we tested whether there was genetic moderation of effects of early maternal sensitivity on social–emotional and cognitive–linguistic development from early childhood onward and whether any detected Gene × Environment interaction effects proved consistent with differential-susceptibility or diathesis–stress models of Person × Environment interaction (N = 695). Two new approaches for evaluating models were employed with 12 candidate genes. Whereas maternal sensitivity proved to be a consistent predictor of child functioning across the primary-school years, candidate genes did not show many main effects, nor did they tend to interact with maternal sensitivity/insensitivity. These findings suggest that the developmental benefits of early sensitive mothering and the costs of insensitive mothering look more similar than different across genetically different children in the current sample. Although acknowledgement of this result is important, it is equally important that the generally null Gene × Environment results reported here not be overgeneralized to other samples, other predictors, other outcomes, and other candidate genes.
Water tracks are zones of high soil moisture that route shallow groundwater down-slope, through the active layer and above the ice table. A water track in Taylor Valley, McMurdo Dry Valleys, was analysed for surface hydrogeological, geochemical, and biological characteristics in order to test the hypothesis that water tracks provide spatial structure to Antarctic soil ecosystems by changing the physical conditions in the soil environment within the water tracks from those outside the water tracks. The presence of the water track significantly affected the distribution of biotic and abiotic ecosystem parameters: increasing soil moisture, soil salinity, and soil organic matter within the water track relative to soils outside the water track, and reducing soil phosphate, soil pH, and the population of nematodes and other invertebrates in water track soils relative to off track soils. These results suggest that water tracks are distinct and extreme ecological zones in Taylor Valley that provide long-range (kilometre to multi- kilometre) structure to Antarctic hillslope ecosystems through physical control on soil moisture and solute content. Contrary to expectations, these high soil-moisture sites are not hotspots for faunal biological activity because high soil salinity makes them suitable habitats for only the most halo-tolerant organisms.
Nanoscale metal–insulator–metal (MIM) diodes consisting of a nanoscale-thickness insulator layer sandwiched between two dissimilar metal layers offer the potential for very high frequency alternating current to direct current signal rectification. Active nanoscale tuning of electronic tunneling through the insulator layer to form point contact diodes has previously been limited to barriers composed of soft organic films due to the force limitations of conductive-atomic force microscopy. In this paper, MIM diodes with oxide-based insulators are formed in situ with sub-nanometer depth precision and characterized using a nanoindenter equipped with electrical testing capabilities. Simultaneous measurement of both electrical and nano-mechanical information is accomplished in an MIM stack of the form Nb/Nb2O5/boron-doped diamond nanoindenter tip. Using this technique, we show that the diode behavior can be electromechanically tuned over a range of more than 1 V at equivalent currents via small changes in indentation depth and the results can be modeled using a Fowler–Nordheim approximation.
Studies of stellar populations have been reinvigorated during the last decade by the advent of large-area sky surveys such as SDSS, 2MASS, RAVE, and others. These data, together with theoretical and modeling advances, are revolutionizing our understanding of the nature of the Milky Way, and galaxy formation and evolution in general. The abundance of substructure in the multi-dimensional space of various observables, such as position, kinematics, and metallicity, is by now proven beyond doubt, and demonstrates the importance of mergers in the growth of galaxies. Unlike smooth models that involve simple components, the new data reviewed here clearly exhibit many irregular structures, such as the Sagittarius dwarf tidal stream and the Virgo and Pisces overdensities in the halo, and the Monoceros stream closer to the Galactic plane. These recent developments have made it clear that the Milky Way is a complex and dynamic structure, one that is still being shaped by the merging of neighboring smaller galaxies. Here we summarize developments over the last decade in our mapping of the stellar content of the Milky Way, as well as recent attempts to map the dark matter halo by Loebman et al. (2012) and ISM dust distribution by Berry et al. (2012). We also briefly discuss the next generation of wide-field sky surveys, exemplified by Gaia and LSST, which will improve measurement precision manyfold, and comprise billions of individual stars.
Our State-Level Economic Model incorrectly forecast the outcome of the presidential election. The model's projections were based on the two-party vote in the prior election, the status of the incumbent party in the election/reelection cycle, national and state unemployment rates, and changes in real per capita personal income levels for state residents. Even before the Republican nomination process began, President Obama's success in the 2008 campaign coupled with the electoral advantage typically enjoyed by first-term incumbents bode well for his reelection chances. However, by the arrival of the fall campaign, unemployment remained high and income growth was stagnant, meaning that the president faced significant economic headwinds. Our estimates indicated that Governor Romney would carry most of the battleground states. We were wrong. President Obama carried all but one of them.
Nearly all forecast models of US presidential elections provide estimates of the national two-party vote (Campbell 2008). Each of the nine forecasts published in the 2008 forecasting issue of PS: Political Science and Politics made national popular vote total predictions for the major party candidates, while only one provided an expected result in the Electoral College (Klarner 2008). These national vote models are assumed to be reliable forecasts of who is likely to win the general election. In most cases, this assumption is reasonable. It becomes problematic, however, at precisely the point that forecasts are most interesting: when elections are close. In tight elections, national forecasts can and have produced a “winner” different from the actual winner. Consider the forecasts and ultimate outcome of the 2000 election. Each of the 2000 presidential election forecasts predicted vice president Al Gore to win a majority of the two-party popular vote, which he did, but none correctly predicted governor George W. Bush to assume the presidency (Campbell 2001). Never in US history have White House residents been determined through a national popular vote. Presidential elections are decided through contests in the states and the District of Columbia. The forecast model we developed explicitly models the presidential contest based on factors inherent to these 51 jurisdictions. This modeling approach allows us to make a projection of the Electoral College result, which popular vote estimates cannot.
Engaging students in the design, administration, and postelection analysis of an exit poll can be an excellent experiential learning activity. Lelieveldt and Rossen (2009) argue that exit polls are a “perfect teaching tool” because they provide students with a cooperative (rather than competitive) learning experience; help students better connect theory, methodology, and course substance; and allow students to move outside of the classroom by branching out into the community. As professors at the University of Colorado, Denver (UCD), we have organized student exit polling during the 2008 and 2010 elections in the Denver area for research methods and elections classes. Although we have found these exit polls to be rewarding experiences for instructors and students alike, the reality is that conducting an exit poll with a group of polling neophytes, in the confines of a single semester, can be challenging. In this article, we discuss strategies and issues for instructors to consider when using an exit poll as an experiential learning exercise.
To place the Mediterranean diet (MedDi) in the context of the cultural history of the Middle East and emphasise the health effects of some of the biblical seven species – wheat, barley, grapes, figs, pomegranates, olives and date honey.
Design
Review of the literature concerning the benefits of these foods.
Setting
Middle East and Mediterranean Basin.
Subjects
Mediterranean populations and clinical studies utilising the MedDi.
Results and conclusions
The MedDi has been associated with lower rates of CVD, and epidemiological evidence promotes the benefits of consuming fruit and vegetables. Recommended foods for optimal health include whole grain, fish, wine, pomegranates, figs, walnuts and extra virgin olive oil. The biblical traditional diet, including the seven species and additional Mediterranean fruits, has great health advantages, especially for CVD. In addition to the diet, lifestyle adaptation that involves increasing physical activity and organised meals, together with healthy food choices, is consistent with the traditional MedDi. The MedDi is a manageable, lifestyle-friendly diet that, when fortified with its biblical antecedent attributes, may prove to be even more enjoyable and considerably healthier in combating the obesogenic environment and in decreasing the risks of the non-communicable diseases of modern life than conventional, modern dietary recommendations. The biblical seven species, together with other indigenous foods from the Middle East, are now scientifically recognised as healthy foods, and further improve the many beneficial effects of the MedDi.