Tailoring the dispersion characteristics in planar arrays of discrete and coalesced split ring resonators

In this report, the coupling and dispersion characteristics of discrete and coalesced square resonators was investigated in the MHz regime. Resonators with one and three gaps were considered. When the resonators are not in direct contact, the number of gaps has little effect upon the total coupling, which is negative. When the resonators are connected so that they share one side, the coupling can change drastically depending on the number of gaps. In particular, when the shared side has a gap, the total coupling coefficient switches to positive values, making it possible for forward travelling waves to propagate on arrays. Experimental, numerical and analytical data verify this behaviour

Winter Survival and Resource Use of Translocated Northern Bobwhite in the Mid-Atlantic United States

Northern bobwhite (Colinus virginianus; hereafter, bobwhite) in the Mid-Atlantic United States have been experiencing precipitous population declines due to a combination of habitat deterioration, urban and suburban sprawl, change in forest management regimes, and farming practices. In recent years, restocking of bobwhite through translocation efforts has gained interest to rebuild local populations. However, empirical studies are warranted to understand the limitations of translocation as it relates to its potential use for long-term population recovery and persistence in this region. Further, few studies nation-wide have evaluated resource use and survival during the non-breeding season on translocated sites. As such, we translocated 360 bobwhites from source populations from southern latitudes during March–April 2015–2017 into 2 different landscape types similar to the source population vegetative communities (agricultural cropland dominated in Maryland, USA versus pine forest dominated in New Jersey, USA) and tested the effects of habitat fragmentation on survival and habitat use during the subsequent non-breeding season. We found habitat fragmentation negatively affecting survival and resource use among translocated bobwhite on fragmented cropland-dominated sites as compared to larger unfragmented forested sites. Survival was lower on cropland sites compared to forested sites such that bobwhite in cropland-dominated landscapes were \u3e125 times less likely to survive the winter than those on forested sites. In our examination of resource use, bobwhite in structurally complex forested sites used cut pine, early-successional woody, early-successional herbaceous, and thinned pine more than what was available on the landscape. On the cropland sites bobwhite used food plots, early-successional woody, and mixed woods more than what was available on the landscape and only food plots at the home range scale. While larger unfragmented forested bobwhite habitat ultimately provided a more successful translocation landscape, birds still had large home ranges and relatively low survival. Therefore, proper pine management may be necessary to optimize habitat availability during the non-breeding season. Our findings provide rare information on demographic resiliency and resource use for translocated bobwhite during the non-breeding season. Further, this research provides valuable information to improve future translocation efforts in the Mid-Atlantic

Extrapolating Survival from Randomized Trials Using External Data: A Review of Methods.

This article describes methods used to estimate parameters governing long-term survival, or times to other events, for health economic models. Specifically, the focus is on methods that combine shorter-term individual-level survival data from randomized trials with longer-term external data, thus using the longer-term data to aid extrapolation of the short-term data. This requires assumptions about how trends in survival for each treatment arm will continue after the follow-up period of the trial. Furthermore, using external data requires assumptions about how survival differs between the populations represented by the trial and external data. Study reports from a national health technology assessment program in the United Kingdom were searched, and the findings were combined with "pearl-growing" searches of the academic literature. We categorized the methods that have been used according to the assumptions they made about how the hazards of death vary between the external and internal data and through time, and we discuss the appropriateness of the assumptions in different circumstances. Modeling choices, parameter estimation, and characterization of uncertainty are discussed, and some suggestions for future research priorities in this area are given

Winter Survival and Habitat Selection by Translocated Northern Bobwhite in the New Jersey Pine Barrens: Preliminary Results

Northern bobwhite (Colinus virginianus) populations have been experiencing precipitous range-wide declines for more than 50 years; some of the steepest declines occurring in the Mid-Atlantic states. These declines are largely attributed to habitat deterioration from urban sprawl, change in forest management, and intensive farming. This ongoing study aims to evaluate the efficacy of translocating wild bobwhites into the New Jersey Pine Barrens as a means to restore their historic populations. Translocation has proven relatively successful in augmenting bobwhite populations in other regions as well as restoring populations of gallinaceous species. This portion of the study aims to investigate what bobwhites require during winter months (October—March) in the Mid-Atlantic to survive until summer for reproduction. The study site, Pine Island Cranberry Company, is the largest privately owned tract of land (6,800 hectares) in New Jersey, with habitat comprised of pitch pine (Pinus rigida), shortleaf pine (Pinus echinata), scrub oak (Quercus ilicifolia), and early successional forbs and grasses. For three consecutive years (2015—2017) prior to breeding season, we will translocate 80 radio-collared bobwhites (40 male, 40 female) to Pine Island from wild populations in southwest Georgia. These bobwhites are radio-located 3—5 times per week throughout the year while this portion of the study focuses on the winter months. We are collecting microhabitat measurements (e.g., basal density, groundcover, understory, and canopy closure) from 30 random telemetry location points, per covey, per habitat type to characterize winter habitat use. Survival is estimated using staggered-entry Kaplan-Meier analyses and a Cox proportional hazard model in R to determine covariates of daily mortality. We are reporting on the first 2 years of results

Summer Survival of Translocated Northern Bobwhite in the New Jersey Pine Barrens: Preliminary Results

Northern bobwhite (Colinus virginianus) have declined precipitously since the 1960s, largely due to habitat deterioration and changes in land use; some of the highest declines have been observed in the Mid-Atlantic States. In other regions, attempts to augment bobwhite populations have been relatively successful using translocation. As part of a long-term restocking program, focal areas for translocation in the mid-Atlantic region were identified by biologists at a National Bobwhite Conservation Initiative (NBCI) workshop. The objective of this project is to evaluate translocation to restore bobwhite populations in the New Jersey Pine Barrens, a focal area designated with a high ranking for potential bobwhite recovery. The study site, Pine Island Cranberry Co., is the largest privately owned land tract (\u3e6,000 hectares) in New Jersey, with a mix of shortleaf pine (Pinus echinata), pitch pine (P. rigida), scrub oak (Quercus ilicifolia), and early successional forbes and grasses. For three consecutive years (2015—2017) prior to breeding season, we are translocating eighty radio-collared bobwhite (40 male, 40 female) from wild populations in southwest Georgia. These individuals are radio-located 3-5 times per week, year round. We are collecting microhabitat measurements (e.g., groundcover, understory, and canopy closure) and monitoring nests to characterize habitat use, nest site selection, and nest fate. Survival is estimated using staggered-entry Kaplan-Meier analyses and a Cox proportional hazard model in R to determine covariates of daily mortality. Six of 14 nests were successful in summer 2015 (66 known hatches), and 0 of 12 nests were successful in summer 2016. Snake depredation was the cause of 41.7% of failed nests in 2016. Preliminary analyses produce a five-month adult survival rate of 0.455 (SE = 0.138) for summer 2015 and 0.270 (SE = 0.0516) for 2016. Our planned third summer (2017) of data collection will increase our understanding of these disparate survival estimates

Using rank data to estimate health state utility models

In this paper we report the estimation of conditional logistic regression models for the Health Utilities Index Mark 2 and the SF-6D, using ordinal preference data. The results are compared to the conventional regression models estimated from standard gamble data, and to the observed mean standard gamble health state valuations. For both the HUI2 and the SF-6D, the models estimated using ordinal data are broadly comparable to the models estimated on standard gamble data and the predictive performance of these models is close to that of the standard gamble models. Our research indicates that ordinal data have the potential to provide useful insights into community health state preferences. However, important questions remain

Tunable capacitor arrays of coalesced resonators for dispersion control

In this work, the coupling and dispersion characteristics of coalesced resonators as a function of their capacitance is investigated, with the goal of developing novel ways of dispersion control. When planar resonators are coalesced and their shared side is capacitively loaded, the total coupling coefficient is positive, allowing for the propagation of forward magnetoinductive waves. By varying the capacitive load on their shared side, the sign and size of the total coupling can be controlled. This is demonstrated in an 11-element array, where the magnetoinductive wave can switch between forward and backward propagation depending on the capacitive load of the shared side. Furthermore, there is a critical value of the ratio between the capacitive loads on shared and non-shared sides, at which the coupling becomes zero, effectively cutting of wave propagation on the structure. It is shown that the structure can be tuned in two ways: maintain a constant operating frequency while tuning the coupling, or tune the operating frequency while keeping the coupling constant. At the same time, an optimisation procedure for setting up numerical simulations to match the experimental data is proposed. The simulations provided significant insight on the electric coupling's behaviour. Experimental, numerical and analytical data verify this behaviour

Disrupted Maturation of the Microbiota and Metabolome among Extremely Preterm Infants with Postnatal Growth Failure

Growth failure during infancy is a major global problem that has adverse effects on long-term health and neurodevelopment. Preterm infants are disproportionately affected by growth failure and its effects. Herein we found that extremely preterm infants with postnatal growth failure have disrupted maturation of the intestinal microbiota, characterized by persistently low diversity, dominance of pathogenic bacteria within the Enterobacteriaceae family, and a paucity of strictly anaerobic taxa including Veillonella relative to infants with appropriate postnatal growth. Metabolomic profiling of infants with growth failure demonstrated elevated serum acylcarnitines, fatty acids, and other byproducts of lipolysis and fatty acid oxidation. Machine learning algorithms for normal maturation of the microbiota and metabolome among infants with appropriate growth revealed a pattern of delayed maturation of the microbiota and metabolome among infants with growth failure. Collectively, we identified novel microbial and metabolic features of growth failure in preterm infants and potentially modifiable targets for intervention

3-D printed bandpass filters with coupled vertically extruded split ring resonators

The additive manufacturing process of multimaterial extrusion offers performance advantages using functional materials including conductors while making accessible the third dimension in the design of electronics. In this work we show that the additional geometrical freedom offered by this technique can be exploited for the design and realisation of filters made of three- dimensional (3D) resonators that exhibit enhanced characteristics. The coupling properties of 3D grounded square split ring resonators (SRRs) are initially explored. We demonstrate by simulations and experiments that SRRs with finite height display significantly stronger coupling compared to equivalent thin printed circuit structures. The observed trend can be exploited for designing filters with wider operational bandwidths for a given footprint, or miniaturized layouts and enhanced compatibility with fabrication limits for minimum feature size and spacing without performance degradation. This concept is demonstrated by presenting results of full-wave simulations for sample bandpass filters with identical footprint but formed by coupled 3D square SRRs of different heights, showing that filters with taller resonators exhibit increasingly wider bandwidths. Two filter prototypes with centre frequencies at 1.6 GHz and 2.45 GHz are manufactured by multimaterial 3D printing. The measured characteristics of these prototypes are found to be in good agreement with numerical simulations taking into account the effect of the lossier metallic and dielectric materials used in 3D printing and confirm the predicted larger bandwidth of the filters made of 3D SRRs with marginally higher insertion losses