Volumetric microvascular imaging of human retina using optical coherence tomography with a novel motion contrast technique

Phase variance-based motion contrast imaging is demonstrated using a spectral domain optical coherence tomography system for the in vivo human retina. This contrast technique spatially identifies locations of motion within the retina primarily associated with vasculature. Histogram-based noise analysis of the motion contrast images was used to reduce the motion noise created by transverse eye motion. En face summation images created from the 3D motion contrast data are presented with segmentation of selected retinal layers to provide non-invasive vascular visualization comparable to currently used invasive angiographic imaging. This motion contrast technique has demonstrated the ability to visualize resolution-limited vasculature independent of vessel orientation and flow velocity

Chemical Repellents

Agricultural depredations caused by blackbirds can be managed with various lethal and nonlethal methods, including chemical repellents. For many people, nonlethal chemical repellents represent an appealing approach to managing crop depredation because the depredating birds are targeted but not killed; they are just inconvenienced. An effective repellent application can cause the crop-depredating birds to leave their present feeding site and seek food elsewhere. Where the birds go to feed is immaterial to the producer as long as the birds leave the producer\u27s field. Thus, an effective repellent application will not likely affect the overall size of the blackbird population, but it may reduce the population associated with depredation and thereby reduce losses within the treated field. As a consequence, nearby crop fields might incur greater damage unless appropriate crop protection measures are employed. Blackbirds flock to fields of rice, sunflower, corn, and other crops because these sites represent accessible sources of abundant and energy-rich food that is obtainable with relatively little effort. Agricultural crops are especially important to young birds and, in the late summer and fall, newly fledged birds constitute a large portion of many depredating blackbird flocks. Crop fields can provide ideal feeding situations for blackbirds learning to fend for themselves. Ever-increasing alteration of the natural landscape to accommodate expansion of human activities makes it increasingly difficult for blackbirds to find natural sources of food. Field crops are powerful attractions to blackbirds, and depredating birds are not easily dissuaded. The potential benefits of feeding on the crop are great, so there must be a commensurately high potential cost to the birds to discourage them

Review of anthraquinone applications for pest management and agricultural crop protection

We have reviewed published anthraquinone applications for international pest management and agricultural crop protection from 1943 to 2016. Anthraquinone (AQ) is commonly found in dyes, pigments and many plants and organisms. Avian repellent research with AQ began in the 1940s. In the context of pest management, AQ is currently used as a chemical repellent, perch deterrent, insecticide and feeding deterrent in many wild birds, and in some mammals, insects and fishes. Criteria for evaluation of effective chemical repellents include efficacy, potential for wildlife hazards, phytotoxicity and environmental persistence. As a biopesticide, AQ often meets these criteria of efficacy for the non-lethal management of agricultural depredation caused by wildlife. We summarize published applications of AQ for the protection of newly planted and maturing crops from pest birds. Conventional applications of AQ-based repellents include preplant seed treatments [e.g. corn (Zea mays L.), rice (Oryza sativa L.), sunflower (Helianthus annuus L.), wheat (Triticum spp.), millet (Panicum spp.), sorghum (Sorghumbicolor L.), pelletized feed and forest tree species] and foliar applications for rice, sunflower, lettuce (Lactuca sativa L.), turf, sugar beets (Beta vulgaris L.), soybean (Glycine max L.), sweet corn and nursery, fruit and nut crops. In addition to agricultural repellent applications, AQ has also been used to treat toxicants for the protection of non-target birds. Few studies have demonstrated AQ repellency in mammals, including wild boar (Sus scrofa, L.), thirteen-lined ground squirrels (Ictidomys tridecemlineatus,Mitchill), black-tailed prairie dogs (Cyomys ludovicainus, Ord.), common voles (Microtus arvalis, Pallas), housemice (Musmusculus, L.), Tristram’s jirds (Meriones tristrami, Thomas) and black rats (Rattus rattus L.). Natural sources of AQ and its derivatives have also been identified as insecticides and insect repellents. As a natural or synthetic biopesticide, AQ is a promising candidate for many contexts of non-lethal and insecticidal pest management

Horned lark damage to pre-emerged canola seedlings

Winter canola (Brassica napus L.) is considered the most promising domestically-produced oilseed feed-stock for biodiesel production and for diversifying wheat (Triticum aestivum L.)-based cropping systems in the Inland Pacific Northwest, USA. Winter canola field experiments conducted in east-central Washington were completely destroyed, and commercial fields were damaged or destroyed, over several years by large flocks of horned larks (Eremophilia alperestis L.) that ate the cotyledon leaves of pre-emerged and newly-emerged seedlings. Numerous control methods were attempted in field experiments, including laying bird netting over the entire experiment, placement of a life-size predator decoy in a field experiment, loud propane-powered cannon blasts, and mixing garlic with canola seed before planting followed by spraying garlic water on the soil surface. None of the attempted control methods were successful. This is the first report in the literature of horned lark damage to pre-emerged and newly-emerged canola seedlings. We discuss questions relevant to our novel account as well as potential abatement using falcons and non-toxic chemical repellents for the protection of industrial canola crops associated with horned lark depredation

Frightening Devices

By their nature, avian frightening devices are intended to provide temporary (days, weeks) relief from a specific depredation or conflict situation. Ideally, the method applied will produce an immediate fright response, causing depredating birds to leave and to stay away as long as the method is in place. Longer-term (months, years) resource protection would involve methods such as crop varietal improvement, blackbird population management, or habitat manipulation. Frightening devices primarily affect the avian auditory and visual senses. With few exceptions (e.g., avian distress or alarm calls), frightening devices are not species-specific.Very few frightening devices have been subjected to adequate scientific evaluation, so their efficacy under field conditions is often unknown. When field tests have been conducted, flaws in experimental design and analysis have rendered most trials inconclusive as to their effectiveness (Bomford and O\u27Brien 1990). Anderson et al. (2013) surveyed fruit crop producers in five states and reported that \u3e50% of respondents considered auditory scare devices to be slightly effective or not effective in reducing bird damage. The specific types of auditory deterrents were not indicated. Relatively few published reports of frightening devices include testing against blackbirds. Therefore, the usefulness of many aural and visual devices for managing blackbirds can only be judged by extrapolating from studies that have focused on species other than icterids, such as corvids and gulls, in settings such as landfills and orchards, which are not usually associated with blackbirds

The statistical strength of experiments to reject local realism with photon pairs and inefficient detectors

Because of the fundamental importance of Bell's theorem, a loophole-free demonstration of a violation of local realism (LR) is highly desirable. Here, we study violations of LR involving photon pairs. We quantify the experimental evidence against LR by using measures of statistical strength related to the Kullback-Leibler (KL) divergence, as suggested by van Dam et al. [W. van Dam, R. Gill and P. Grunwald, IEEE Trans. Inf. Theory. 51, 2812 (2005)]. Specifically, we analyze a test of LR with entangled states created from two independent polarized photons passing through a polarizing beam splitter. We numerically study the detection efficiency required to achieve a specified statistical strength for the rejection of LR depending on whether photon counters or detectors are used. Based on our results, we find that a test of LR free of the detection loophole requires photon counters with efficiencies of at least 89.71%, or photon detectors with efficiencies of at least 91.11%. For comparison, we also perform this analysis with ideal unbalanced Bell states, which are known to allow rejection of LR with detector efficiencies above 2/3.Comment: 18 pages, 3 figures, minor changes (add more references, replace the old plots, etc.)

Multi-isotopic (δ2H, δ13C, δ15N) tracing of molt origin for European starlings associated with U.S. dairies and feedlots

Introduced bird species can become invasive in agroecosystems and their management is inhibited if their origin and movements are not well understood. Stable isotope measurements of feathers can be used to infer molt origins and interstate movements in North America. We analyzed stable-hydrogen (δ2H), carbon (δ13C) and nitrogen (δ 15N) isotope ratios in feathers to better understand the molt origin of European starlings (Sturnus vulgaris) collected at dairies and feedlots throughout the United States. Primary feathers were used from 596 adult and 90 juvenile starlings collected during winter at dairies and feedlots that experience starling damages in Arizona, California, Colorado, Idaho, Illinois, Iowa, Kansas, Minnesota, Missouri, Nebraska, Nevada, New Hampshire, New Mexico, New York, North Carolina, Oregon, Texas, Vermont, Washington and Wisconsin. The best-fit model indicated that the combination of feather δ2H, δ13C and δ15N values best predicted the state where samples were collected and thus supported use of this approach for tracing molt origins in European starlings. Interestingly, molt origins of starlings collected at dairies and feedlots generally west of −90˚ longitude (i.e. 11 of 15 states west of the Mississippi River, including Wisconsin) were assigned to the collection state and/or the state adjacent to the collection state. In contrast, molt origins of starlings collected generally east of −90˚ longitude (four of five eastern states) were not assigned to the collection state and/or the state adjacent to the collection state. Among all starlings (N = 686), 23% were assigned to the collection state and 19% were assigned to the state adjacent to the collection state. Among all males (N = 489) and all females (N = 197), 23% and 26% were assigned to the collection state and 19% and 13% were assigned to the state adjacent to the collection state, respectively. We observed a greater proportion (88%) of juvenile starlings assigned to states other than their collection state (i.e. potentially a result of natal dispersal) than that proportion (76%) in adult starlings. This study included an unprecedented sample of feather isotopes from European starlings throughout the United States. As a novel contribution to the ecology and management of invasive and migratory passerines, we demonstrate how such feather isoscapes can be used to predict molt origin and, potentially, interstate movements of European starlings for subsequent ecological and management investigations

NESTING ECOLOGY OF THE NORTHERN BEARDLESSTYRANNULET (CAMPTOSTOMA IMBERBE) IN THE LOWER RIO GRANDE VALLEY OF TEXAS, U.S.A.

During 2002–2003, we studied the breeding ecology of the Northern Beardless-Tyrannulet (Camptostoma imberbe), a poorly known and rare permanent resident in the Lower Rio Grande Valley of Texas, United States of America. We found 28 nests in clusters of Spanish moss (Tillandsia usneoides) or ball moss (T. recurvata), 93% of which were in cedar elm (Ulmus crassifolia) trees. Nest-building, incubation, and nestling periods averaged 7.0, 14.0, and 18.5 days, respectively. Of the 28 nests, 43% were successful, while 38% of the failed nests showed obvious signs of depredation. Nests were located in areas with denser Tillandsia growth and with taller trees than nearby non-used areas. Availability of this habitat may limit the population size of Northern Beardless-Tyrannulets in the Lower Rio Grande Valley

Efficacy of an Avian Repellent Applied Using Drop Nozzle-Equipped Ground Rigs in Reducing Blackbird Damage to Sunflower

In North Dakota large flocks of blackbirds feed on ripening crops, after breeding and prior to migration, resulting in an annual damage estimate averaging $3.5 million for sunflower. Since the repellent needs to be ingested to be effective, one obstacle is applying sufficient repellent directly to the sunflower face. Thus, we tested efficacy of an anthraquinone-based repellent when applied via drop-nozzle to sunflower using enclosed blackbirds in a semi-natural field setting. We used a ground-rig equipped with 360 Undercover® drop nozzle sprayers to apply 20 gal/ac of solution to sunflower plots with a product application rate of 1.0 gal/ac (13% AQ). To test efficacy, we installed bird enclosures (12 x 13 x 10 ft) to house 10 captive, male red-winged blackbirds (Agelaius phoeniceus) for 23 days on 10 treated and 10 untreated plots. The repellent did not cause birds to consume more alternative diet (i.e., red milo). Sunflower yield did not differ between treated and untreated enclosures as a result of blackbird damage. Variation in the amount of repellent reaching the face of the sunflower and subsequent residues was a limitation of the application method. Efficacy may be improved by increasing the application rate or repellent in the tank mixture, but sprayer technology and economic limitations related to repellent costs need to be considered. Future studies should aim to optimize the amount of product in tank mixtures and the repellent formulation as designed for specific pests and crops

Efficacy of repellent-treated structural barriers for Richardson’s ground squirrels (\u3ci\u3eUrocitellus richardsonii\u3c/i\u3e (Sabine)) and house mice (\u3ci\u3eMus musculus\u3c/i\u3e L.)

The worldwide presence of vertebrate pests such as rodents has created a need for non-lethal control methods that can be applied to integrated pest management plans. Chemical repellents are often a useful wildlife management tool as they can be directly applied to a commodity or structure to prevent infringement and damage. We assessed the efficacy of an anthraquinone (AQ)-based repellent in a structural barrier model against Richardson’s ground squirrels (Urocitellus richardsonii (Sabine)) (RGS) and house mice (Mus musculus L.). The AQbased repellent was applied to pieces of burlap which were secured over each end of a small section of PVC pipe. Unadulterated enrichment food was then offered within the enclosed PVC pipe to motivate interactions with repellent-treated and untreated burlap barriers. Defeat of the barrier was defined as a physical breach by means of chewing the burlap or burlap/repellent barrier such that the test animal was able to gain entry to the hide and the enrichment food. RGS defeated 55% (±7.9) of untreated barriers, 25% (±6.8) of barriers treated with 50% dilution AQ-based repellent, and 27.5% (±5.6) of barriers treated with 0% dilution AQ-based repellent. House mice defeated 100% (±0.0) of untreated barriers, 20.5% (±6.4) of barriers treated with 50% dilution AQbased repellent, and 45.5% (±7.8) of barriers treated with 0% dilution AQ-based repellent. Relative to untreated barriers, AQ treatments reduced defeat of the barrier by 50–55% for RGS and 55–80% for house mice. RGS showed a marked decrease in consumption of enrichment food after exposure to AQ. The 0% dilution of AQtreated structural barrier had more individuals of both RGS and house mice chew through the structural barrier than the 50% dilution despite the increased concentration of AQ. We hypothesized that the additional water in the 50% dilution may have allowed for greater absorption of the repellent throughout the burlap fibers, thus enabling greater interaction with the AQ-treated barriers. Our results indicate that AQ-based repellents show promise as structural barriers for RGS and house mice