Restoration of linear disturbances from oil-and-gas exploration in boreal landscapes: How can network models help?

In western Canada, decades of oil-and-gas exploration have fragmented boreal landscapes with a dense network of linear forest disturbances (seismic lines). These seismic lines are implicated in the decline in wildlife populations that are adapted to function in unfragmented forest landscapes. In particular, anthropogenic disturbances have led to a decline of woodland caribou populations due to increasing predator access to core caribou habitat. Restoration of seismic lines aims to reduce the landscape fragmentation and stop the decline of caribou populations. However, planning restoration in complex landscapes can be challenging because it must account for a multitude of diverse aspects. To assist with restoration planning, we present a spatial network optimization approach that selects restoration locations in a fragmented landscape while addressing key environmental and logistical constraints. We applied the model to develop restoration scenarios in the Redrock-Prairie Creek caribou range in northwestern Alberta, Canada, which includes a combination of caribou habitat and active oil-and-gas and timber extraction areas. Our study applies network optimization at two distinct scales to address both the broad-scale restoration policy planning and project-level constraints at the level of individual forest sites. We first delineated a contiguous set of coarse-scale regions where restoration is most cost-effective and used this solution to solve a fine-scale network optimization model that addresses environmental and logistical planning constraints at the level of forest patches. Our two-tiered approach helps address the challenges of fine-scale spatial optimization of restoration activities. An additional coarse-scale optimization step finds a feasible starting solution for the fine-scale restoration problem, which serves to reduce the time to find an optimal solution. The added coarse-scale spatial constraints also make the fine-scale restoration solution align with the coarse-scale landscape features, which helps address the broad-scale restoration policies. The approach is generalizable and applicable to assist restoration planning in other regions fragmented by oil-and-gas activities.

Denser forests across the USA experience more damage from insects and pathogens.

Forests across much of the United States are becoming denser. Trees growing in denser stands experience more competition for essential resources, which can make them more vulnerable to disturbances. Forest density can be expressed in terms of basal area, a metric that has been used to assess vulnerability of some forests to damage by certain insects or pathogens. A raster map of total tree basal area (TBA) for the conterminous United States was compared with annual (2000-2019) survey maps of forest damage due to insects and pathogens. Across each of four regions, median TBA was significantly higher within forest areas defoliated or killed by insects or pathogens than in areas without recorded damage. Therefore, TBA may serve as a regional-scale indicator of forest health and a first filter for identifying areas that merit finer-scale analysis of forest conditions.

Safety and Efficacy of Hypersonic Vitrectomy for Retinal Reattachment Surgery in Proliferative Vitreoretinopathies.

Introduction: To investigate the safety and efficacy of the Vitesse hypersonic vitrectomy device for retinal reattachment surgery in proliferative vitreoretinopathy (PVR) or proliferative diabetic vitreoretinopathy (PDVR) cases. The Vitesse device utilizes hypersonic technology to liquefy instead of cutting the vitreous, providing an alternative to the traditional pneumatic guillotine cutter. Material and Methods: A prospective, one-armed, non-comparative, open-label study was performed. Sixteen patients with a diagnosis of PVR or PDVR that required retinal reattachment surgery were included. Severity of disease was classified using the Retina Society 1983 classification and Kroll Classification from 2007. Patient data was collected preoperatively, 2 days postoperatively, 1 month postoperatively, and 3 months postoperatively. Efficacy of hypersonic vitrectomy was evaluated, both subjectively using a questionnaire and objectively by means of Supplementary Video documentation, device settings, and data collection of the patients' medical history. Results: In all 16 cases, retinal reattachment surgery could be performed with Vitesse without conversion to a guillotine cutter. The vitreous could be separated from the detached retina completely with no iatrogenic tissue damage. Vitreous traction was documented in one case. In 6 cases, shaving of the vitreous base was performed after early fluid-air exchange with hypersonic vitrectomy without any complications. No adverse events suspected to be related to hypersonic vitrectomy were documented in the follow-up visits. Conclusion: The Vitesse has potential advantages including reduced vacuum volumes with limited amount of turbulence and avoidance vitreoretinal traction. Liquefaction directly in front of the probe entrance allows for continuous unrestricted fluid flow. These factors of hypersonic technology allow to carry out retinal reattachment surgery in PVR or PDVR cases successfully.

Detecting critical nodes in forest landscape networks to reduce wildfire spread.

Although wildfires are an important ecological process in forested regions worldwide, they can cause significant economic damage and frequently create widespread health impacts. We propose a network optimization approach to plan wildfire fuel treatments that minimize the risk of fire spread in forested landscapes under an upper bound for total treated area. We used simulation modeling to estimate the probability of fire spread between pairs of forest sites and formulated a modified Critical Node Detection (CND) model that uses these estimated probabilities to find a pattern of fuel reduction treatments that minimizes the likely spread of fires across a landscape. We also present a problem formulation that includes control of the size and spatial contiguity of fuel treatments. We demonstrate the approach with a case study in Kootenay National Park, British Columbia, Canada, where we investigated prescribed burn options for reducing the risk of wildfire spread in the park area. Our results provide new insights into cost-effective planning to mitigate wildfire risk in forest landscapes. The approach should be applicable to other ecosystems with frequent wildfires.

Optimal invasive species surveillance in the real world: practical advances from research.

When alien species make incursions into novel environments, early detection through surveillance is critical to minimizing their impacts and preserving the possibility of timely eradication. However, incipient populations can be difficult to detect, and usually, there are limited resources for surveillance or other response activities. Modern optimization techniques enable surveillance planning that accounts for the biology and expected behavior of an invasive species while exploring multiple scenarios to identify the most cost-effective options. Nevertheless, most optimization models omit some real-world limitations faced by practitioners during multi-day surveillance campaigns, such as daily working time constraints, the time and cost to access survey sites and personnel work schedules. Consequently, surveillance managers must rely on their own judgments to handle these logistical details, and default to their experience during implementation. This is sensible, but their decisions may fail to address all relevant factors and may not be cost-effective. A better planning strategy is to determine optimal routing to survey sites while accounting for common daily logistical constraints. Adding site access and other logistical constraints imposes restrictions on the scope and extent of the surveillance effort, yielding costlier but more realistic expectations of the surveillance outcomes than in a theoretical planning case.

Pressure dependent direct transtissue transmission of eyewall, sclera and vitreous body in the range of 350-1050nm.

PURPOSE: For transscleral application of optical radiation or light to the eye, it is important to know the transmission and absorbance of the tissue layers of the eyewall. The impact of photochemical energy to the retina located directly at the point of contact with the radiation emitter must be considered as well as the absorbance in choroid and retina. Therefore, the direct transmission of ex vivo porcine eyewalls and vitreous body were measured in this study. METHODS: At ex vivo porcine eyes (N=221) pressure dependent transmission measurements were performed with a pressure inducing setup. Pressure and wavelength dependent direct transmission of eyewall and vitreous body of porcine eyes were described for different applied pressures (23mmHg, 78mmHg and 132mmHg). The transmissions were investigated within the spectral range of 350-1050nm. In addition to the complete eyewall transmission measurements, the transmission of sclera, vitreous body and water was measured individually and the transmission of retina and choroid was calculated. RESULTS: With increasing wavelength and pressure, a significant transmission increase of the eyewall could be achieved (p<0.05). At 400nm and 132mmHg the transmission raised to 0.10%. At 1050nm it increased up to a value of 12.22%. In the visible spectrum, the direct transmission was always below 3.17%. The differences in eyewall transmission of eyes with different iris colors were significant at low pressure. With increasing pressure, the effect strength decreased and the differences lost their significance. CONCLUSIONS: The pressure and wavelength dependent direct transmission of the eyewall and the vitreous body significantly increased with increasing pressure. This results are benefical for technical and clinical safety, research and development of illumination devices. It is necessary to know the intraocular brightness in the eye during diaphanoscopy, photocoagulation application to determine hazards.

Unusual Primary Ocular Manifestation of Sarcoidosis.

A 23-year-old male patient presented with very mild visual disturbances, but a distinct prominence of the optic discs, more pronounced in the right than in the left eye. The ophthalmic symptoms initially seemed trivial, but a large-scale interdisciplinary workup later identified them as the presenting symptoms of sarcoidosis affecting lung and eyes. A standard steroid monotherapy successfully caused regression of the ophthalmic findings.

Managing biological invasions in urban environments with the acceptance sampling approach.

Detections of invasive species outbreaks are often followed by the removal of susceptible host organisms in order to slow the spread of the invading pest population. We propose the acceptance sampling approach for detection and optional removal of susceptible host trees to manage an outbreak of the emerald ash borer (EAB), a highly destructive forest pest, in Winnipeg, Canada. We compare the strategy with two common delimiting survey techniques that do not consider follow-up management actions such as host removal. Our results show that the management objective influences the survey strategy. The survey-only strategies maximized the capacity to detect new infestations and prioritized sites with high likelihood of being invaded. Comparatively, the surveys with subsequent host removal actions allocated most of the budget to sites where complete host removal would minimize the pest's ability to spread to uninvaded locations. Uncertainty about the pest's spread causes the host removal measures to cover a larger area in a uniform spatial pattern and extend to farther distances from already infested sites. If a decision maker is ambiguity-averse and strives to avoid the worst-case damages from the invasion, the optimal strategy is to survey more sites with high host densities and remove trees from sites at farther distances, where EAB arrivals may be uncertain, but could cause significant damage if not detected quickly. Accounting for the uncertainty about spread helps develop a more robust pest management strategy. The approach is generalizable and can support management programs for new pest incursions.

Short-Term Intraocular Pressure Rise during Locally Induced Force by Ophthalmologic Surgery Applications.

PURPOSE: Surgical or diagnostic procedures are often accompanied by a short-term increase in intraocular pressure (IOP). A short-term increase in IOP can occur during refractive procedures, vitreoretinal surgery, transillumination, photocoagulation, or cryocoagulation. A porcine eye model was chosen (n = 89) to compile comparable study data and to de termine correlations between the force induced and the resulting intraocular pressure while excluding the effect of surgeons. METHODS: The IOP was measured in the anterior chamber. IOP changes were induced by applying an external force and measured when using a cannula, trocar, and cryocoagulation (n = 32), and correlations between force and resulting IOP were assessed (n = 57). RESULTS: A correlation was noted between the force induced and the IOP increase, which showed a linear dependency. The insertion of a 29-G cannula caused a mean ΔIOP value of 49.1 ± 2.9 mm Hg and an external force of 0.76 N, and that of a 23-G trocar 344.4 ± 5.9 mm Hg and 6.09 N, respectively. The rise in IOP during a simulated cryocoagulation reached values between 57.3 ± 14.8 mm Hg (cryoprobe tip diameter: 0.9 mm) and 130.3 ± 2.9 mm Hg (cryoprobe tip diameter: 7.0 mm). CONCLUSION: The values of the forces applied can be converted into the resulting IOP based on the specific action. Surgical or diagnostic procedures should, therefore, be evaluated with regard to preexisting pathologies, such as glaucoma.

Changes in intraocular pressure after intravitreal fluocinolone acetonide (ILUVIEN): real-world experience in three European countries.

AIMS: The ILUVIEN Registry Safety Study is an ongoing, multicentre, open-label, observational study collecting real-world data on the safety and effectiveness of the 0.2 µg/day fluocinolone acetonide (FAc) implant in patients treated according to the European label requirements. METHODS: Patients included in this analysis were treated for the licensed indication of chronic diabetic macular oedema (cDMO; that is, DMO that persists or recurs despite treatment). Data presented in the current analysis were collected from patient records up to 6 March 2017. Visual acuity (VA) data, including mean change in VA over time and at last observation, intraocular pressure (IOP) over the course of the study, IOP events, use of IOP-lowering therapy and cup:disc ratio were analysed. Information on additional DMO treatments post-FAc implant was also captured. RESULTS: Five hundred and sixty-three patients (593 eyes) were enrolled on the study. Mean IOP for the overall population remained within the normal range throughout follow-up and 76.7% of patients did not require IOP-lowering therapy following treatment with the FAc implant. Sixty-nine per cent of eyes did not require additional DMO treatments. Mean VA in the overall population increased from 51.9 letters at baseline to 55.6 letters at month 12, with a significant increase of 2.9 letters at last observation. Patients with short-term cDMO experienced greater VA gains than those with long-term cDMO. CONCLUSIONS: The results of this analysis are comparable with those of other studies, including the Fluocinolone Acetate for Macular Edema study. The study reinforces the good safety and effectiveness profile of FAc, and demonstrates the benefit of early FAc treatment.

A safety rule approach to surveillance and eradication of biological invasions.

Uncertainty about future spread of invasive organisms hinders planning of effective response measures. We present a two-stage scenario optimization model that accounts for uncertainty about the spread of an invader, and determines survey and eradication strategies that minimize the expected program cost subject to a safety rule for eradication success. The safety rule includes a risk standard for the desired probability of eradication in each invasion scenario. Because the risk standard may not be attainable in every scenario, the safety rule defines a minimum proportion of scenarios with successful eradication. We apply the model to the problem of allocating resources to survey and eradicate the Asian longhorned beetle (ALB, Anoplophora glabripennis) after its discovery in the Greater Toronto Area, Ontario, Canada. We use historical data on ALB spread to generate a set of plausible invasion scenarios that characterizes the uncertainty of the beetle's extent. We use these scenarios in the model to find survey and tree removal strategies that minimize the expected program cost while satisfying the safety rule. We also identify strategies that reduce the risk of very high program costs. Our results reveal two alternative strategies: (i) delimiting surveys and subsequent tree removal based on the surveys' outcomes, or (ii) preventive host tree removal without referring to delimiting surveys. The second strategy is more likely to meet the stated objectives when the capacity to detect an invader is low or the aspirations to eradicate it are high. Our results provide practical guidelines to identify the best management strategy given aspirational targets for eradication and spending.

A new hypervolume approach for assessing environmental risks.

Assessing risks of uncertain but potentially damaging events, such as environmental disturbances, disease outbreaks and pest invasions, is a key analytical step that informs subsequent decisions about how to respond to these events. We present a continuous risk measure that can be used to assess and prioritize environmental risks from uncertain data in a geographical domain. The metric is influenced by both the expected magnitude of risk and its uncertainty. We demonstrate the approach by assessing risks of human-mediated spread of Asian longhorned beetle (ALB, Anoplophora glabripennis) in Greater Toronto (Ontario, Canada). Information about the human-mediated spread of ALB through this urban environment to individual geographical locations is uncertain, so each location was characterized by a set of probabilistic rates of spread, derived in this case using a network model. We represented the sets of spread rates for the locations by their cumulative distribution functions (CDFs) and then, using the first-order stochastic dominance rule, found ordered non-dominant subsets of these CDFs, which we then used to define different classes of risk across the geographical domain, from high to low. Because each non-dominant subset was estimated with respect to all elements of the distribution, the uncertainty in the underlying data was factored into the delineation of the risk classes; essentially, fewer non-dominant subsets can be defined in portions of the full set where information is sparse. We then depicted each non-dominant subset as a point cloud, where points represented the CDF values of each subset element at specific sampling intervals. For each subset, we then defined a hypervolume bounded by the outermost convex frontier of that point cloud. This resulted in a collection of hypervolumes for every non-dominant subset that together serve as a continuous measure of risk, which may be more practically useful than averaging metrics or ordinal rank measures. Overall, the approach offers a rigorous depiction of risk in a geographical domain when the underlying estimates of risk for individual locations are represented by sets or distributions of uncertain estimates. Our hypervolume-based approach can be used to compare assessments made with different datasets and assumptions.

Proteomic Analysis of Vitreous Humor in Retinal Vein Occlusion.

PURPOSE: To analyze the protein profile of human vitreous of untreated patients with retinal vein occlusion (RVO). METHODS: Sixty-eight vitreous humor (VH) samples (44 from patients with treatment naïve RVO, 24 controls with idiopathic floaters) were analyzed in this clinical-experimental study using capillary electrophoresis coupled to mass spectrometer and tandem mass spectrometry. To define potential candidate protein markers of RVO, proteomic analysis was performed on RVO patients (n = 30) and compared with controls (n = 16). To determine validity of potential biomarker candidates in RVO, receiver operating characteristic (ROC) was performed by using proteome data of independent RVO (n = 14) and control samples (n = 8). RESULTS: Ninety-four different proteins (736 tryptic peptides) could be identified. Sixteen proteins were found to be significant when comparing RVO and control samples (P = 1.43E-05 to 4.48E-02). Five proteins (Clusterin, Complement C3, Ig lambda-like polypeptide 5 (IGLL5), Opticin and Vitronectin), remained significant after using correction for multiple testing. These five proteins were also detected significant when comparing subgroups of RVO (central RVO, hemi-central RVO, branch RVO) to controls. Using independent samples ROC-Area under the curve was determined proving the validity of the results: Clusterin 0.884, Complement C3 0.955, IGLL5 1.000, Opticin 0.741, Vitronectin 0.786. In addition, validation through ELISA measurements was performed. CONCLUSION: The results of the study reveal that the proteomic composition of VH differed significantly between the patients with RVO and the controls. The proteins identified may serve as potential biomarkers for pathogenesis induced by RVO.

Portable single port 23-gauge vitrectomy in postoperative endophthalmitis.

AIM: To evaluate the safety and effectiveness of the Intrector(®) for treating postoperative endophthalmitis. MATERIALS AND METHODS: In a retrospective multicenter study, patients who received a single port 23-gauge core pars plana vitrectomy and isovolumetric injection of vancomycin, ceftazidime, and dexamethasone/amphotericin B using the Intrector(®) for postoperative endophthalmitis of intermediate severity (grade II or III vitreous inflammation and best-corrected visual acuity between hand movements and 0.3 logMAR [logarithm of the minimum angle of resolution]) were evaluated. Improvement in visual acuity, resolution of intraocular inflammation, the need for additional surgical procedures, and the development of complications were evaluated at a 1-month follow-up examination. RESULTS: Fifteen patients (mean age 55.6±7.2 years) underwent treatment with the Intrector(®). The mean vitreous volume aspirated was 0.78±0.22 mL. The vitreous samples indicated positive microorganism culture results in six of the 15 cases, but the samples were positive when analyzed by real-time polymerase chain reaction in all cases (15/15). The mean best-corrected visual acuity improved significantly (P=0.01) from 0.88±0.29 (logMAR) to 0.32±0.28. Each patient demonstrated at least three lines of visual improvement. No additional medical or surgical interventions were required, and the complete resolution of intraocular inflammation was noted in all patients at the 1-month follow-up examination. No procedure-related complications were observed. CONCLUSION: The Intrector(®) may be a safe and effective treatment option for infectious postoperative endophthalmitis. Larger studies comparing the outcomes of the Intrector(®) to the traditional treatments for postoperative endophthalmitis need to be conducted before its role in the treatment of postoperative endophthalmitis can be properly defined.

Using a network model to assess risk of forest pest spread via recreational travel.

Long-distance dispersal pathways, which frequently relate to human activities, facilitate the spread of alien species. One pathway of concern in North America is the possible spread of forest pests in firewood carried by visitors to campgrounds or recreational facilities. We present a network model depicting the movement of campers and, by extension, potentially infested firewood. We constructed the model from US National Recreation Reservation Service data documenting more than seven million visitor reservations (including visitors from Canada) at campgrounds nationwide. This bi-directional model can be used to identify likely origin and destination locations for a camper-transported pest. To support broad-scale decision making, we used the model to generate summary maps for 48 US states and seven Canadian provinces that depict the most likely origins of campers traveling from outside the target state or province. The maps generally showed one of two basic spatial patterns of out-of-state (or out-of-province) origin risk. In the eastern United States, the riskiest out-of-state origin locations were usually found in a localized region restricted to portions of adjacent states. In the western United States, the riskiest out-of-state origin locations were typically associated with major urban areas located far from the state of interest. A few states and the Canadian provinces showed characteristics of both patterns. These model outputs can guide deployment of resources for surveillance, firewood inspections, or other activities. Significantly, the contrasting map patterns indicate that no single response strategy is appropriate for all states and provinces. If most out-of-state campers are traveling from distant areas, it may be effective to deploy resources at key points along major roads (e.g., interstate highways), since these locations could effectively represent bottlenecks of camper movement. If most campers are from nearby areas, they may have many feasible travel routes, so a more widely distributed deployment may be necessary.

Effects of core vitrectomy in the treatment of age-related macular degeneration.

PURPOSE: To investigate the clinical efficacy and safety of an additional core vitrectomy to the standard therapy in patients with exudative age-related macular degeneration (ARMD). METHODS: In this prospective, controlled, single-centre study, 50 eyes of 50 patients (mean age: 74.1 ± 7.1; median 74 (69/78)) with ARMD were enrolled and randomized 1:1 to group 1 - core vitrectomy additional to three times injections of ranibizumab (3x Rbz) and Group 2 - 3x Rbz (control). 1 16 of 25 eyes in Group 1(64%) and 12 of 25 (48%) in Group 2 had a posterior vitreous detachment (PVD) prior to start of the study. Changes in best-corrected visual acuity (BCVA) using ETDRS charts, central macular thickness and macular volume (OCT) as well as the rate of reinjection with an OCT-based pro renata (PRN) protocol were monitored prospectively over 48 weeks. Forty-seven eyes completed follow-up at week 48. RESULTS: In Group 1, 4 of 24 lost 1 line of BCVA (16.7%) and 3 of 24 lost 2 lines (12.5%), whereas 17 of 24 gained more than 1 line (70.8%) and improved in average by 9.8 letters. In Group 2, 3 of 23 remained stable and 20 of 23 gained more than or exactly 1 line (78.3%), resulting in 14.3 letters, with no loss of lines. Central macular thickness decreased by 85.58 µm (28.8%) in Group 1 and by 121.43 µm (32.68%) in Group 2 compared with baseline. In Group 1, four patients received three additional and two patients, two additional Rbz injections. In Group 2, three patients received three additional, three patients two and 12 patients one additional Rbz injections. This yielded in an average injection rate of 3.66 in Group 1 and 4.17 in Group 2 over 48 weeks. Posterior vitreous detachment (PVD) was identified in Group 1 in 16 of 24 (66.7%) and in Group 2 in 12 of 23 (52.2%) patients at baseline. At week 48, 6 of 8 (75%) of the patients in Group 1 with initial attached vitreous showed a vitreal detachment, whereas only 1 of 11 (9%) in Group 2 had a new occurred detachment of the vitreous. No systemic or ocular adverse events were noticed. CONCLUSION: An initial core vitrectomy combined with a conventional ranibizumab injection regimen for exudative AMD patients was safe and lead to similar functional results with less intravitreal ranibizumab injections over 48 weeks.

Exploring critical uncertainties in pathway assessments of human-assisted introductions of alien forest species in Canada.

Long-distance introductions of alien species are often driven by socioeconomic factors, such that conventional "biological" invasion models may not be capable of estimating spread fully and reliably. In this study, we demonstrate a new technique for assessing and reconstructing human-mediated pathways of alien forest species entries to major settlements in Canada via commercial road transportation and domestic trade. We undertook our analysis in three steps. First, we used existing data on movement of commodities associated with bark- and wood-boring forest pests to build a probabilistic model of how the organisms may be moved from one location to another through a transportation network. We then used this model to generate multiple sets of predictions of species arrival rates at every location in the transportation network, and to identify the locations with the highest likelihood of new incursions. Finally, we evaluated the sensitivity of the species arrival rates to uncertainty in key model assumptions by testing the impact of additive and multiplicative errors (by respectively adding a uniform random variate or symmetric variation bounds to the arrival rate values) on the probabilities of pest transmission from one location to another, as well as the impact of the removal of one or more nodes and all connecting links to other nodes from the underlying transportation network. Overall, the identification of potential pest arrival hotspots is moderately robust to uncertainties in key modeling assumptions. Large urban areas and major border crossings that have the highest predicted species arrival rates have the lowest sensitivities to uncertainty in the pest transmission potential and to random changes in the structure of the transportation network. The roadside survey data appears to be sufficient to delineate major hubs and hotspots where pests are likely to arrive from other locations in the network via commercial truck transport. However, "pass-through" locations with few incoming and outgoing routes can be identified with lower precision. The arrival rates of alien forest pests appear to be highly sensitive to additive errors. Surprisingly, the impact of random changes in the structure of the transportation network was relatively low.

Correlation of inflammatory and proangiogenic cytokines from undiluted vitreous samples with spectral domain OCT scans, in untreated branch retinal vein occlusion.

PURPOSE: To assess the levels of inflammatory and angiogenic cytokines in undiluted vitreous from treatment-naïve patients with macular edema secondary to nonischemic branch retinal vein occlusion (BRVO), with flow cytometric bead array (CBA) and to correlate the results with subjective and multiple spectral-domain optical coherence tomography (SD-OCT) parameters. METHODS: A total of 43 eyes from 43 patients (mean age 69.7 years, 23 male) were divided into groups of new, "fresh" (n = 28; mean duration after onset 4.1 months) and older BRVO (n = 15; 11.6 months). Because of macular edema, these patients underwent an intravitreal therapy combining a single-site 23 g core vitrectomy with bevacizumab and dexamethasone. Undiluted vitreous was then analyzed for interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and vascular endothelial growth factor isoform A (VEGF-A) levels with CBA and correlated with visual acuity (VA), clinical parameters of BRVO (type and perfusion status), and morphologic parameters, such as central macular thickness, central retinal thickness, thickness of the neurosensory retina, thickness of the serous retinal detachment, and the disruption of the ellipsoid line (photoreceptor inner and outer segments) and the external limiting membrane, as measured with SD-OCT. Twenty-eight undiluted vitreous samples from patients with idiopathic, nonuveitis vitreous floaters served as the controls. RESULTS: The mean IL-6 was 23.2 pg/mL (standard deviation, ±48.8), MCP-1 was 602.6 (±490.3), and VEGF-A was 161.8 (±314.3), and this was higher than in the control group, which had a mean IL-6 of 6.2 ± 3.4 pg/mL (P = 0.17), MCP-1 of 253.2 ± 73.5 (P < 0.0000001), and VEGF-A of 7.0 ± 4.9 (P < 0.003). In all BRVO samples, IL-6 correlated positively with MCP-1 and VEGF-A (correlation coefficient r = 0.79 and r = 0.46, respectively). VEGF-A was the only cytokine to correlate significantly with SD-OCT parameters (thickness of the neurosensory retina r = 0.31; disruption of the ellipsoid line r = 0.33). In the older BRVO group, there was a positive correlation between cytokines (IL-6 with MCP-1, r = 0.77; Il-6 with VEGF-A, r = 0.68; MCP-1 and VEGF-A, r = 0.68), whereas only IL-6 correlated with MCP-1 in the fresh group (r = 0.8). CONCLUSION: The inflammatory markers and VEGF-A were elevated in the vitreous fluid of patients with BRVO, and these correlated with one another. VEGF-A was more often correlated with the morphologic changes assessed by SD-OCT, whereas the inflammatory markers had no significant influence on SD-OCT changes.

A new multicriteria risk mapping approach based on a multiattribute frontier concept.

Invasive species risk maps provide broad guidance on where to allocate resources for pest monitoring and regulation, but they often present individual risk components (such as climatic suitability, host abundance, or introduction potential) as independent entities. These independent risk components are integrated using various multicriteria analysis techniques that typically require prior knowledge of the risk components' importance. Such information is often nonexistent for many invasive pests. This study proposes a new approach for building integrated risk maps using the principle of a multiattribute efficient frontier and analyzing the partial order of elements of a risk map as distributed in multidimensional criteria space. The integrated risks are estimated as subsequent multiattribute frontiers in dimensions of individual risk criteria. We demonstrate the approach with the example of Agrilus biguttatus Fabricius, a high-risk pest that may threaten North American oak forests in the near future. Drawing on U.S. and Canadian data, we compare the performance of the multiattribute ranking against a multicriteria linear weighted averaging technique in the presence of uncertainties, using the concept of robustness from info-gap decision theory. The results show major geographic hotspots where the consideration of tradeoffs between multiple risk components changes integrated risk rankings. Both methods delineate similar geographical regions of high and low risks. Overall, aggregation based on a delineation of multiattribute efficient frontiers can be a useful tool to prioritize risks for anticipated invasive pests, which usually have an extremely poor prior knowledge base.

Dispersal of invasive forest insects via recreational firewood: a quantitative analysis.

Recreational travel is a recognized vector for the spread of invasive species in North America. However, there has been little quantitative analysis of the risks posed by such travel and the associated transport of firewood. In this study, we analyzed the risk of forest insect spread with firewood and estimated related dispersal parameters for application in geographically explicit invasion models. Our primary data source was the U.S. National Recreation Reservation Service database, which records camper reservations at > 2,500 locations nationwide. For > 7 million individual reservations made between 2004 and 2009 (including visits from Canada), we calculated the distance between visitor home address and campground location. We constructed an empirical dispersal kernel (i.e., the probability distribution of the travel distances) from these "origin-destination" data, and then fitted the data with various theoretical distributions. We found the data to be strongly leptokurtic (fat-tailed) and fairly well fit by the unbounded Johnson and lognormal distributions. Most campers ( approximately 53%) traveled <100 km, but approximately 10% traveled > 500 km (and as far as 5,500 km). Additionally, we examined the impact of geographic region, specific destinations (major national parks), and specific origin locations (major cities) on the shape of the dispersal kernel, and found that mixture distributions (i.e., theoretical distribution functions composed of multiple univariate distributions) may fit better in some circumstances. Although only a limited amount of all transported firewood is likely to be infested by forest insects, this still represents a considerable increase in dispersal potential beyond the insects' natural spread capabilities.