Pattern Of Patches Research Articles

Transition from windfall- to patch-driven outbreak dynamics of the spruce bark beetle Ips typographus

The purpose of this study is to increase the basic understanding of outbreak dynamics in order to improve the management of bark beetle outbreaks. The spruce bark beetle Ips typographus is a major disturbance agent of European forests and is the continent’s most economically and environmentally damaging bark beetle. Outbreaks of the spruce bark beetle are often triggered by large windfall episodes, and we have utilized a unique opportunity to study a Slovakian outbreak where little salvage logging was performed in some areas after a 2.5millionm3 storm-felling in 2004.Our analyses focused on the first five years after the windfall, and we used a combination of empirical data and simulation models to understand the spatial patterns of beetle-killed forest patches developing during the outbreak. The univoltine beetle population used an increasing proportion of the windfelled trees during the two first seasons after the storm, but from the third season onwards our comparisons of inter-patch distance distributions indicated a transition from beetle production largely in windfall areas to a self-sustaining outbreak with infestation patches developing independently of the windthrows. The size of new infestation patches formed after this transition was modeled as a function of beetle pressure, estimated by the proportion of a circle area surrounding new patches that was covered by infestation patches the previous year. Our model results of patch size distribution did not correspond well with the empirical data if patch formation was modeled as a pure dispersal–diffusion process. However, beetle aggregation on individual trees appears to be important for patch development, since good correspondence with empirical data was found when beetle aggregation was incorporated in the modeled dispersal process. The strength of correspondence between the beetle aggregation model and the empirical data varied with the density of aggregation trees in the modeled landscape, and reached a maximum of 83% for a density of three aggregation trees per infestation patch.Our results suggest that efficient removal of windfelled trees up until the start of the second summer after a major windfall is important to avoid a transition into a patch-driven bark beetle outbreak that is very difficult to manage. Our results also indicate that the outcome of a patch-driven outbreak is difficult to predict, since the development of new infestation patches is not a simple function of beetle pressure but is also affected by beetle behavior and local forest conditions.

Dermatofibroma looks dermoscopically different on trunk versus extremities.

Several dermoscopic patterns have been described in dermatofibroma (DF), but little is known about morphologic features of DF in different anatomic locations. The aim of this study was to evaluate the association between the dermoscopic pattern of DF and the anatomic location. We conducted a retrospective observational study of 169 DF that were evaluated for the presence of dermoscopic structures and patterns. Patients' age and sex were recorded, while the anatomic location of each lesion was categorized in 2 main groups, namely extremities and trunk. The possible correlation between the dermoscopic pattern and the anatomic site was tested using the χ2 test or the Fisher's exact test, as appropriate. DFs resulted mainly located on extremities as compared to trunk (79.2% and 20.7%, respectively). Frequencies of dermoscopic patterns of DF were the following: atypical (26.6%), network and patch (23.7%), total structureless (17.1%), structureless and patch (9.5%), total network (6.5%), network and structureless (3.5%), double network (2.9%), white network and total structureless (2.9%), white network (2.9%), multifocal patches (2.4%), and total patch (1.8%). A significant association between network and patch pattern and extremities (27.6%) was found (P<0.05). Similarly structureless and patch pattern resulted completely absent on trunk and quite frequent on extremities (11.9%; P<0.05). In contrast, total structureless was the most common pattern on the trunk (31.4%) and less represented on extremities (P<0.05). Total network pattern followed the same trend (P<0.05). Our study reveals that the dermoscopic pattern of DF is significantly influenced by the anatomic location of the lesion. The "classic" pattern with a white patch surrounded by network dermoscopically characterizes DFs of the extremities, while DFs located on the trunk often exhibit different findings.

Residual Vegetation Patches within Natural Boreal Wild Fires: Characterizing by Pattern Metrics, Land Cover Expec tations and Proximity to Firebreak Features

Wildfires typically contain a considerable number of wildfire residual patches of various size, shape and composition. These residual patches can occupy substantial areas of fire footprints, thus understanding their patterns provides insight for emulating forest disturbances in harvesting operations. Eleven natural boreal wild fire events within Ontario are examined. Each fire was ignited by lighting, occurred in anthropogenically undisturbed forested landscapes and was never suppressed. The spatial patterns of the residual patches are assessed based on selected spatial metrics (related to composition, configuration and fragmentation). The char acterization of the occurrence of wildfire residual patches and their spatial patterns in reference to land cover composition and proximity to firebreak features, is imperative to examine the effects of vegetation or land cover on residual patch occurrence and distribution. This study examines which land cover types are more likely to dominate the existing residual patches. The results indicate that the proportion of land area that sur vived burning varies considerably across fire events, ranging from the smallest fire event at 3% (F09) to the largest event at 21% (F06). While the majority of residual patches are in close proximity (within 200 m) to surface water and the edge of the fire footprint, it is revealed that low abundance land cover types (e.g., treed wetland and sparse conifer) tend to dominate residual patches in certain areas.

Landscape Patch Pattern Effect on Relationships between Soil Properties and Earthworm Assemblages: A Comparison of two Farmlands of Different Spatial Structure

ABSTRACT Our survey was carried out in two study sites of approximately 3.3 ha each located in the Suwalki Lake District in NE Poland in the year 2008. Earthworms and soil samples were collected during two campaigns (spring and autumn) from 25 × 25 cm and 30 cm deep sampling points. The complex arable landscape (CAL) supported higher earthworm diversity, density and biomass than the similarly managed but homogeneous arable landscape (HAL). The spring and autumn earthworm sampling campaigns revealed very different patterns, and we conclude that autumn sampling is the most adequate for biomonitoring. On the other hand, the spring collections were significantly correlated to soil physical parameters, thus spring sampling is more suitable for studying such correlations. Significant correlations occurred almost exclusively for CAL and the soil parameters significantly relating with earthworm community were: soil moisture, nitrogen and organic carbon contents. The possible reason for it is the presence of numer...

Ring-bursting behavior en route to turbulence in narrow-gap Taylor-Couette flows.

We investigate the Taylor-Couette system where the radius ratio is close to unity. Systematically increasing the Reynolds number, we observe a number of previously known transitions, such as one from the classical Taylor vortex flow (TVF) to wavy vortex flow (WVF) and the transition to fully developed turbulence. Prior to the onset of turbulence, we observe intermittent bursting patterns of localized turbulent patches, confirming the experimentally observed pattern of very short wavelength bursts (VSWBs). A striking finding is that, for a Reynolds number larger than that for the onset of VSWBs, a new type of intermittently bursting behavior emerges: patterns of azimuthally closed rings of various orders. We call them ring-bursting patterns, which surround the cylinder completely but remain localized and separated in the axial direction through nonturbulent wavy structures. We employ a number of quantitative measures including the cross-flow energy to characterize the ring-bursting patterns and to distinguish them from the background flow. These patterns are interesting because they do not occur in the wide-gap Taylor-Couette flow systems. The narrow-gap regime is less studied but certainly deserves further attention to gain deeper insights into complex flow dynamics in fluids.

Scalable High-Performance Image Registration Framework by Unsupervised Deep Feature Representations Learning.

Feature selection is a critical step in deformable image registration. In particular, selecting the most discriminative features that accurately and concisely describe complex morphological patterns in image patches improves correspondence detection, which in turn improves image registration accuracy. Furthermore, since more and more imaging modalities are being invented to better identify morphological changes in medical imaging data, the development of deformable image registration method that scales well to new image modalities or new image applications with little to no human intervention would have a significant impact on the medical image analysis community. To address these concerns, a learning-based image registration framework is proposed that uses deep learning to discover compact and highly discriminative features upon observed imaging data. Specifically, the proposed feature selection method uses a convolutional stacked autoencoder to identify intrinsic deep feature representations in image patches. Since deep learning is an unsupervised learning method, no ground truth label knowledge is required. This makes the proposed feature selection method more flexible to new imaging modalities since feature representations can be directly learned from the observed imaging data in a very short amount of time. Using the LONI and ADNI imaging datasets, image registration performance was compared to two existing state-of-the-art deformable image registration methods that use handcrafted features. To demonstrate the scalability of the proposed image registration framework, image registration experiments were conducted on 7.0-T brain MR images. In all experiments, the results showed that the new image registration framework consistently demonstrated more accurate registration results when compared to state of the art.

Lifeact and Utr230 induce distinct actin assemblies in cell nuclei

Nuclear actin assembly in somatic cells has been an enigma for a long time. Recently, with the advancement of novel F-actin probes, researchers have started to uncover this mystery. In this study, we investigated the actin dynamics in somatic cell nuclei using two probes: Lifeact and Utr230. Surprisingly, we observed that both Lifeact and Utr230 significantly interfered with actin dynamics in cell nuclei. Moreover, these two probes induced distinct patterns of nuclear actin assembly. While Lifeact induced filamentous actin assembly in cell nuclei, Utr230 led to various patterns of actin aggregates, including fibers, small puncta, and large patches. Moreover, the interference of actin dynamics by Lifeact was limited to nuclear actin, while Utr230 induced actin aggregation in both the nucleus and cytoplasm. Using time-lapse microscopy, we found that Lifeact-induced actin fibers remained steady over hours of observation, indicating a deficiency of nuclear F-actin reorganization. These results suggest that Lifeact and Utr230 both interfere with nuclear actin dynamics but with distinct mechanisms. This is an important finding for research on nuclear actin assembly and highlights the potential value of these two probes for exploring the native mechanisms underlying nuclear actin dynamics, which appear to be altered in the presence of these probes.

Patch patterns of lowland beech forests in a gradient of management intensity

Forest development phases (FDPs) represent patches that are in different stages of the forest life cycle as conceived in the shifting mosaic concept. FDPs are a widely used framework to describe forest stand structure and dynamics. Natural forests are characterized by small patch sizes, a full set of FDPs and a large vertical heterogeneity which is considered crucial for their biodiversity. Forest management approaches that promote such characteristics of high naturalness are increasingly recommended for biodiversity conservation. Here we investigate the effect of a 10-year naturalness-promoting management regime on forest stand structure, expressed through different patterns in FDP structure and composition.We studied 22 beech forest stands in north-eastern Germany that are managed in two different ways (naturalness-promoting management and other management) or that have been unmanaged for varying periods of time (recently, 20–35years and long-term, 65 to more than 100years). FDPs were investigated in 2012/13 across the total area of the study sites (714ha). The FDP assignment is based on a dichotomic decision tree with variables such as diameter at breast height, canopy cover, deadwood amount, regeneration cover and tree height. We analyzed FDP patch size, aggregation and mean minimum distance between patches of the same FDP and structural evenness of FDP proportions.For stands with naturalness-promoting management we found that: (1) there are different FDP proportions, FDP patch sizes and distances between patches of the same FDP compared to the other three management types; (2) there are significant differences in comparison to long-term unmanaged stands in terms of the aggregation indices of the initial phase, optimum phases and the disintegration phase; (3) these stands have the highest aggregation of the regeneration phase, which differs significantly from the other management types; and (4) they contain a similar FDP distribution to that in natural beech forests.In conclusion, naturalness-promoting management supports small-scale patch heterogeneity and maintains forest structure and life cycle that are closer to natural and unmanaged stands compared to other management types.

Numerical analysis of inhomogeneous Schottky diode with discrete barrier height patches

ABSTRACTThe potential profile inside the semiconductor at the metal–semiconductor contact is simulated by numerically solving the Poisson equation and the drift diffusion equations for inhomogeneous Schottky diode. From the simulated potential and the electron and hole concentrations, the drift-diffusion current as a function of bias is calculated. The simulation is carried out for various distribution patterns of barrier height patches at the metal–semiconductor contact to study the effect of barrier inhomogeneities on the Schottky diode parameters, namely barrier height and ideality factor and their temperature dependence. It is found that barrier height decreases and ideality factor increases with increase in the deviation of discrete barrier height patches in the distribution. The resulting barrier parameters are studied to understand the effect of barrier inhomogeneities on the current–voltage characteristics of inhomogeneous Schottky contact.

Computer-assisted identification of proliferative diabetic retinopathy in color retinal images.

Advanced (proliferative) stage of diabetic retinopathy (DR) is indicated by the growth of thin, fragile and highly unregulated vessels, neovascularization (NV). In order to identify proliferative diabetic retinopathy (PDR), our approach models the micro-pattern of local variations using texture based analysis and quantifies the structural changes in vessel patterns in localized patches, to map them to the confidence score of being neovascular using supervised learning framework. Rule-based criteria on patch-level neovascularity scores in an image is used for the decision of absence or presence of PDR. Evaluated using 3 datasets, our method achieves 96% sensitivity and 92.6% specificity for localizing NV. Image-level identification of PDR achieves high sensitivity of 96.72% at 79.6% specificity and high specificity of 96.50% at 73.22% sensitivity. Our approach could have potential application in DR grading where it can localize NVE regions and identify PDR images for immediate intervention.

Extended fault inversion with random slipmaps: a resolution test for the 2012Mw7.6 Nicoya, Costa Rica earthquake

Inversions for the full slip distribution of earthquakes provide detailed models of earthquake sources, but stability and non-uniqueness of the inversions is a major concern. The problem is underdetermined in any realistic setting, and significantly different slip distributions may translate to fairly similar seismograms. In such circumstances, inverting for a single best model may become overly dependent on the details of the procedure. Instead, we propose to perform extended fault inversion trough falsification. We generate a representative set of heterogeneous slipmaps, compute their forward predictions, and falsify inappropriate trial models that do not reproduce the data within a reasonable level of mismodelling. The remainder of surviving trial models forms our set of coequal solutions. The solution set may contain only members with similar slip distributions, or else uncover some fundamental ambiguity such as, for example, different patterns of main slip patches. For a feasibility study, we use teleseismic body wave recordings from the 2012 September 5 Nicoya, Costa Rica earthquake, although the inversion strategy can be applied to any type of seismic, geodetic or tsunami data for which we can handle the forward problem. We generate 10 000 pseudo-random, heterogeneous slip distributions assuming a von Karman autocorrelation function, keeping the rake angle, rupture velocity and slip velocity function fixed. The slip distribution of the 2012 Nicoya earthquake turns out to be relatively well constrained from 50 teleseismic waveforms. Two hundred fifty-two slip models with normalized L1-fit within 5 per cent from the global minimum from our solution set. They consistently show a single dominant slip patch around the hypocentre. Uncertainties are related to the details of the slip maximum, including the amount of peak slip (2–3.5 m), as well as the characteristics of peripheral slip below 1 m. Synthetic tests suggest that slip patterns such as Nicoya may be a fortunate case, while it may be more difficult to unambiguously reconstruct more distributed slip from teleseismic data.

The 2009 L’Aquila earthquake coseismic rupture: open issues and new insights from 3D finite element inversion of GPS, InSAR and strong motion data

&lt;p&gt;We present a Finite Element inverse analysis of the static deformation field for the M&lt;sub&gt;w&lt;/sub&gt;= 6.3, 2009 L’Aquila earthquake, in order to infer the rupture slip distribution on the fault plane. An univocal solution for the rupture slip distribution has not been reached yet with negative impact for reliable hazard scenarios in a densely populated area. In this study, Finite Element computed Green’s functions were implemented in a linear joint inversion scheme of geodetic (GPS and InSAR) and seismological (strong motion) coseismic deformation data. In order to fully exploit the informative power of our dense dataset and to honor the complexities of the real Earth, we implemented an optimized source model, represented by a fault plane subdivided in variable size patches, embedded in a high-resolution realistic three-dimensional model of the Apenninic seismo-tectonic setting, accounting for topographic reliefs and rheological heterogeneities deduced from local tomography. We infer that the investigated inversion domain contains two minima configurations in the solution space, i.e. a single- and a double-patch slip distribution, which are almost equivalent, so that the available datasets and numerical models are not able to univocally discriminate between them. Nevertheless our findings suggest that a two high-slip patch pattern is slightly favoured.&lt;/p&gt;

Design and performance analysis of small-sized multiband microstrip patch antenna on custom-made biopolymer substrate

Abstract This paper presents a simple design analysis and performance evaluation of rectangular, slotted, microstrip feed patch antenna. The design processes are performed by employing the finite element method (FEM)-based commercial EM simulation software High-Frequency Structural Simulator (HFSS). The proposed multiband antenna is composed of a rectangular, slotted radiator formed with four arc slots and central square slot, reduced ground plane, and microstrip line for feeding. The patch antenna is excited through the standard 50 Ω RF transmission line, impedance-compliant SMA connector that is connected to the microstrip line. The optimal parametric dimensions from the numerical simulations are used for constructing the physical prototype on a custom-made, ceramic-filled biopolymer substrate of ε r=10.0. Based on simulation results, the experimental data are collected, analyzed, and compared; the surface current distributions on the patch, gain, and radiation patterns are critically discussed. The measured results show the impedance bandwidths for S11 less than -10 dB are 712 MHz at 0.788 GHz band, 1.38 GHz at 3.34 GHz band, and 2.46 GHz at 8.01 GHz band. The good radiation pattern performances, almost stable gain over the bands, and appreciable bandwidths recommend the antenna for operating in RFID, WiMAX, and C/X-band applications.

Livestock redistribute runoff and sediments in semi-arid rangeland areas

Abstract. Semi-arid areas where grazing is the main land use exhibit a "three-phase-mosaic" pattern of dominant surface patches: shrubs, trampling routes, and intershrub areas. This pattern differs from the "two-phase mosaic" seen in grazing-free semi-arid areas. The patches might create a positive feedback process in which enhanced infiltration beneath shrubs minimizes overland flow from under their canopies, thereby strengthening the sink–source mechanism by which overland flow generated between shrubs rapidly infiltrates into the soil beneath them, where it deposits soil particles, litter, nutrients and organic matter, thereby enhancing infiltration by changing the local microtopography, and improving soil properties. To analyze sink–source relationships among the patches in grazed areas in rangelands of the semi-arid northern Negev region of Israel, we constructed small runoff plots, 0.25–1.0 m2 in area, of five types: shrub (Sarcopoterium spinosum), intershrub, route, route–shrub combination, and intershrub–shrub combination. The shrubs always occupied the downslope part of the plot. Overland flow and sediment deposits were measured in all plots during 2007/8 and 2008/9. The combined plots yielded much less overland flow and sediments than intershrub, routes and shrub ones, indicating that the shrubs absorbed almost all the yields of the upper part of their plots. The shrubs generated less runoff and sediments than routes and intershrubs; runoff flows from the routes and intershrubs were similar; sediment yield was highest in the intershrubs. Thus, runoff yield exhibited a two-phase mosaic pattern, and sediment yield, i.e., soil erosion, a three-phase mosaic pattern.

Spatial heterogeneity of soil and vegetation characteristics and soil-vegetation relationships along an ecotone in Southern Mu Us Sandy Land, China

This study aims to examine the changes in the spatial heterogeneity of soil properties at different soil layers, the spatial heterogeneity of soil and vegetation characteristics along an ecotone, and soil-vegetation relationships along the ecotone in a critical area of desertification. A study site was established across a Lespedeza potaninii (dominant) community (LPC) and an Artemisia ordosica (dominant) community (AOC), with the ecotone between these two communities. In this study, “along the ecotone” means from LPC, via the ecotone, and then to AOC. Three parallel transects (300-m long) were arranged at 50-m intervals along the site. Along each transect, at 10-m spacings, 1 m × 1-m quadrats were marked for the vegetation survey and soil sampling. Soil samples were analyzed in the laboratory after natural air-drying. Data analyses were conducted with a combination of classical and geostatistical methods. In most cases, species importance values and soil properties changed significantly (P < 0.05) along the ecotone. Most soil and vegetation variables were moderately spatially autocorrelated. Kriging interpolated maps showed patch patterns of soil chemical properties. The C/(Co + C) values of soil properties were larger at 5–10-cm than those at 0–5-cm. Vegetation characteristics were mainly positively correlated with soil organic carbon (SOC), total nitrogen (TN), and electrical conductivity (EC). TN at 0–5-cm (TN1), EC at 0–5-cm (EC1), and available potassium at 5–10-cm (AK2) were selected as the predictors for plant species richness and diversity in the stepwise regression analysis between vegetation characteristics and soil properties. Soil nutrients decreased significantly (P < 0.05) along the ecotone. Soil and vegetation properties had moderate spatial heterogeneity. Soil properties had a stronger spatial heterogeneity at subsurface layers compared to surface layers. TN1, EC1, and AK2 were the predominant factors for the plant community structure along the ecotone in the critical area of desertification.

A Scalable and Accurate Descriptor for Dynamic Textures Using Bag of System Trees.

The bag-of-systems (BoS) representation is a descriptor of motion in a video, where dynamic texture (DT) codewords represent the typical motion patterns in spatio-temporal patches extracted from the video. The efficacy of the BoS descriptor depends on the richness of the codebook, which depends on the number of codewords in the codebook. However, for even modest sized codebooks, mapping videos onto the codebook results in a heavy computational load. In this paper we propose the BoS Tree, which constructs a bottom-up hierarchy of codewords that enables efficient mapping of videos to the BoS codebook. By leveraging the tree structure to efficiently index the codewords, the BoS Tree allows for fast look-ups in the codebook and enables the practical use of larger, richer codebooks. We demonstrate the effectiveness of BoS Trees on classification of four video datasets, as well as on annotation of a video dataset and a music dataset. Finally, we show that, although the fast look-ups of BoS Tree result in different descriptors than BoS for the same video, the overall distance (and kernel) matrices are highly correlated resulting in similar classification performance.

Titanium surface anodized under UV light irradiation observed by ellipso-microscopy

Photo-corrosion of an anodized titanium surface in 0.05 mol dm−3 sulfuric acid solution was investigated by using an in situ electrochemical ellipso-microscope. Irradiation of ultra-violet (UV) light on an anodized surface, which showed a patch-like bright image on an ellipso-microscopic view due to non-uniform growth of the oxide film, under potentiostatic polarization allowed the flow of a photo-induced anodic current and changed the brightness and patch pattern in the image. This indicates that the irradiation promotes photo-electrochemical reaction, resulting in a change in the thickness and/or structure of the oxide film on the surface. The film change was dependent not only on power density of the irradiation light but also on applied potential during the irradiation and crystallographic orientation of the substrate. Pitting initiation during potentiodynamic polarization in the acid with bromide ions was also monitored using the ellipso-microscope. The irradiation resulted in pitting initiation at lower potentials than those in a non-irradiated condition.

The fate of seeds in the soil: a review of the influence of overland flow on seed removal and its consequences for the vegetation of arid and semiarid patchy ecosystems

Abstract. Since seeds are the principle means by which plants move across the landscape, the final fate of seeds plays a fundamental role in the assemblage, functioning and dynamics of plant communities. Once seeds land on the soil surface after being dispersed from the parent plant, they can be moved horizontally by surface runoff. In arid and semiarid patchy ecosystems, where seeds are scattered into a very heterogeneous environment and intense rainfalls occur, the transport of seeds by runoff to new sites may be an opportunity for seeds to reach more favourable sites for seed germination and seedling survival. Although seed transport by runoff may be of vital importance for the recruitment of plants in these ecosystems, it has received little attention in the scientific literature, especially among soil scientists. The main goals of this review paper are (1) to offer an updated conceptual model of seed fate with a focus on seed destiny in and on the soil; (2) to review studies on seed fate in overland flow and the ecological implications seed transport by runoff has for the origin, spatial patterning and maintenance of patches in arid and semiarid patchy ecosystems; and finally (3) to point out directions for future research. This review shows that seed fate in overland flow may result either in the export of seeds from the system (seed loss) or in the spatial redistribution of seeds within the system through short-distance seed movements (seed displacement). Seed transport by runoff depends on rainfall, slope and soil characteristics. Susceptibility of seed removal varies highly between species and is mainly related to seed traits, including seed size, seed shape, presence of appendages, and ability of a seed to secrete mucilage. Although initially considered as a risk of seed loss, seed removal by runoff has recently been described as an ecological driver that shapes plant composition from the first phases of the plant life by favouring species with seeds able to resist erosion and by selecting for plant traits that prevent seed loss. Moreover, the interaction of seed transport by overland flow with the high seed trapping capacity of vegetated patches results in a "patch-to-patch" transport of seeds that plays a relevant role in vegetation establishment and patterning in arid and semiarid patchy ecosystems. Overall, this review shows how the knowledge about seed fate in overland flow can be used to explain a number of important characteristics of whole plant communities. It also underlines important gaps in knowledge that should be filled in. Future lines of research are proposed in order to broaden our understanding of the origin, maintenance and dynamics of patchiness in arid and semiarid ecosystems and to improve restoration success of intensively eroded ecosystems. Among the most exciting challenges, empirical studies are needed to understand the relevance of short-distance seed displacements in the origin and maintenance of patchiness, addressing the feedbacks between structure and function and abiotic and biotic components, in order to validate existing models about the dynamics of arid and semiarid ecosystems and help to predict future changes under the scenarios of climate change.

Relative influence of local and landscape factors on bird communities vary by species and functional group

Introduction Both fine scale patterns of vegetation and coarser scale landscape patterns affect bird community composition, but the relative importance of these two sets of patterns tends to be context dependent, varying by location and taxonomic group. Here, we explore the relative roles of landscape pattern and stand structure and composition in defining bird communities in 44 remnant oak stands in the Willamette Valley, Oregon. We focused on: (1) whether bird communities are influenced more by landscape (matrix and patch) patterns or stand composition and structure, and (2) in what contexts each of these spatial scales are more important. Specifically, we focused on how different groups of bird species (functional groups, synanthropic and non-synanthropic species, and individual species) were differentially influenced by landscape and more local patterns.

Acoustic Survey along Heraklieon and East Canopus Ancient Greek Cities, Abu Quir Bay, Alexandria, Egypt

The recent development techniques of acoustic sound survey can provide clearly the inferences of seabed texture, grain size or habitat, seafloor bathymetry and sunken archaeology. Acoustic seabed classification and mapping are possible by using a wide range of acoustic imaging systems. The aim of this study is to get a recent seafloor mapping of the seabed characteristics applying side scan sonar sonography, single beam echo-sounding with QTC seabed classification data, remotely operated under water vehicle (ROV) imageries, and sediment analysis in the study area of the Abu-Quir bay, Alexandria, Egypt. Four types of backscattered patterns were recognized: Pattern of lighter tones corresponds to coarse and medium sediments, Darker tones pattern corresponds fine to very fine sand, tonal patches pattern confined to the transition zone from fine to coarse grained sediment. Moreover Pattern with isolated reflections belongs to archaeological remains and rocky outcrop areas. The seabed sediments of the study area were classified into four types; fine sand, medium sand, very fine sand and silty clay. The isolated reflections pattern has been interpreted as rocky outcrops and archaeological remains of the two ancient Greek cities, Heraklieon and East Canopus. The detection of scattered remains of archaeological structures assumed to be parts of historical blocks, buried archaeological feature. The large flat rocky area may be interpreted as the floors of the submerged cities. The borders of both submerged cities were delimited on the mosaic image where, Heraklieon may covered an area about 600 × 1000 m, while East Canopus may covered 550 × 800 m that situated 1.9 Km at the eastern side from the Abo Qir port.