Width Of Edges Research Articles

Successful clinical approach to the metastatic uterine leiomyosarcoma to the epicardium—a case report

BackgroundUterine leiomyosarcoma is a rare and aggressive tumour with a poor prognosis. Its metastases to the heart are even rarer, especially to the epicardium. The majority of reported cardiac metastases of uterine leiomyosarcoma were in the cardiac chambers or intramyocardial. Surgical resection of the uterine leiomyosarcoma in the early stages is the only definitive treatment for this disease. However, in the cases of cardiac metastasis, surgery is recommended only in emergencies and patients with expected beneficial outcomes.Case presentationOur patient was a 49-year-old female referred to the Department of Cardiac Surgery for scheduled surgery of pericardial neoplasia. The patient underwent a hysterectomy and adnexectomy three years prior owing to the uterine leiomyosarcoma. A regular follow-up magnetic resonance imaging of the abdomen and pelvis discovered neoplasia in the diaphragmic portion of the pericardium. No other signs of primary disease relapse or metastases were found. The patient was asymptomatic. The multidisciplinary team concluded that the patient is a candidate for surgery. Surgery included diastolic cardiac arrest achievement and resection of the tumour. Macroscopically, a parietal layer of the pericardium was completely free from the tumour that invaded only the apical myocardium of the left ventricle. Completed histopathology confirmed the diagnosis of leiomyosarcoma of the uterine origin. Three months after surgery, the patient received adjuvant chemotherapy with doxorubicin and dacarbazine. One year after surgery, there are no signs of new metastases.ConclusionsStrict surveillance of patients with uterine leiomyosarcoma after successful treatment of the early stage of the disease is of utmost importance to reveal metastatic disease to the heart in a timely manner and to treat it with beneficial outcomes. Surgery with adjuvant chemotherapy might be a good approach in patients with a beneficial prognosis. From a surgical point of view, it is challenging to assess the appropriate width of the resection edges to be radical enough and, at the same time, sufficiently conservative to ensure the satisfactory postoperative function of the remaining myocardium and avoid repetitive tumour growth. Therefore, intraoperative histopathology should always be performed.

Local-free recurrence survival after breast-conserving surgery and the breast cancer complex treatment

Aim. To determine the frequency of local recurrence of breast cancer (BC) after performing breast-conserving surgery (BCS) during and after complex treatment, to study the risk factors for local recurrence and survival.Materials and methods. A retrospective cohort study of 675 patients with breast cancer who underwent BCS followed by remote radiotherapy was conducted. The frequency of local relapse and risk factors were studied, 3- and 5-year local-free survival. The odds ratios (OR) and 95% confidence intervals (CI) were calculated, and the Kaplan–Meyer curves were constructed.Results. Radical breast resections (RBR) were performed in 46.7% of patients, and oncoplastic breast resections (OBS) in 53.3% of patients. The most common histological type in both groups was invasive cancer with no signs of specificity: 76.9% and 84.1% – in the OBS and RBR groups, respectively. The incidence of cancer in situ was higher in the OBS group: 14.7% vs. 3.3% in the RBR group (p < 0.001), metastases in regional lymph nodes were more frequent in the RBR group: 34.3% against 20.3% in OBS (p < 0.001). According to the immunohistochemical type and degree of differentiation, the groups did not differ. For 3 years, the relapse-free survival rate was 99.7% in both groups, and for 5 years – 99.2% in the OBS group. and 99.7% in the RBR group, 6 years – 98.3% and 98.7%, respectively; no significant differences were found between the groups. There were no statistically significant differences in the frequency of relapses depending on the width of the resection edges from <1 to ≥10 mm. The risk of relapse was increased with a preserved menstrual status (OR 20.05; 95% CI 2.52–159.33), Her2/neu–positive (OR 5.11; 95% CI 1.04–25.09) and triple-negative types (OR 4.02; 95% CI 1.02–15.95), the degree of differentiation of G3 (OR 5.58; 95% CI 1.59–19.64).Conclusion. BCS is characterized by oncological safety; the rate of local relapse within 6 years is 1.5%. Risk factors for relapse include active menstrual status, highly aggressive immunohistochemical types of breast cancer, and low degree of differentiation.

Partially Coherent Dual and Quad Airy‐Like Beams

AbstractPartially coherent multi‐Airy‐like beams are investigated by introducing coordinate transformation parameters and combining them with the theory of multi‐beam superposition under symmetrical conditions, for the case of dual and quad as examples. The accurate propagation position of the mutual‐focusing point is obtained by analyzing the normalized spectral density (SD) curves at different planes. The outcomes show that both the optical frame and the interference pattern can be changed by means of adjusting the coordinate transformation parameters. For a special circumstance, the transverse SD overlapping profile is presented in a rotational four‐square grid. In addition, the coordinate transformation parameters periodically affect the distance between the two main lobes, which provides us a new idea with adjusting the width of the optical frame edges. Moreover, both the peak intensity of the SD and the divergence speed can be controlled by tuning the value of the equivalent beam width. These results may provide new inspiration for applications of partially coherent Airy‐like beams in optical propagation, capture, and communication.

Tuning charge transport in organic semiconductors with nanoparticles and hexamethyldisilazane

In this study, we showcase the use of silicon dioxide (SiO2) nanoparticles and hexamethyldisilazane (HMDS) treatment to regulate the thin film morphology and manipulate charge transport of solution-processed, small-molecular, organic semiconductors. 6,13-Bis(triisopropylsilylethynyl) pentacene (TIPS pentacene) was blended with SiO2 nanoparticles as an exemplary organic semiconductor. A higher concentration of SiO2 nanoparticles were observed near the edge of TIPS pentacene crystals and enlarged the width of crystal edges. This greatly reduced the dendritic crystal growth pattern of TIPS pentacene and contributed to its enhanced orientation uniformity. In addition, the HMDS treatment effectively passivated the silanol groups on the hydrophilic gate dielectrics. As a result, bottom-gate, top-contact TIPS pentacene/SiO2 nanoparticle-based organic thin-film transistors boosted a performance consistency enhancement (defined by the ratio of average mobility to the standard deviation of mobility). The combinational approach to employ SiO2 nanoparticles and HMDS treatment as demonstrated in this work sheds light on important applications in high-performance organic electronics devices on flexible substrate.

THE MODERN ASPECTS OF THE BREAST CONSERVING SURGERY AFTER NEOADJUVANT CHEMOTHERAPY IN PATIENTS WITH BREAST CANCER CT1-3N0-3M0

Introduction. While the “no tumor on ink” approach is generally accepted for breast-conserving surgery (BCS) in patient with breast cancer, it remains unclear whether it is oncologically safe for BCS after neoadjuvant chemotherapy therapy (NACT). The aim of the study is to investigate the optimal width of the resection edges in BCS after NALT and the influence on disease-free and overall survival in patients with breast cancer. Materials and methods. Retrospectively, the medical documentation of 76 patients with breast cancer, who were performed BCS after NACT, was studied. The distribution by stage of breast cancer was as follows: I St. -5 patients, II St. - 55, III St. - 16 (excluded IIIB St.). Invasive cancer of non-specific type was diagnosed in 81.6% of cases, in 6.5% - lobular cancer, in 1.3% - combined breast cancer. Radical breast resections in the classic version were performed in 28 cases, and oncoplastic resections in various modifications were performed in 48 Cases. Results. We present the retrospective data of 76 patients with breast cancer who underwent OSA after NALT in the Department of breast and skin cancer OF the Moscow Institute of medical research. P. A. Herzen. The results of our study demonstrated the oncological safety of OSO with respect to new sizes of tumor nodes after NALT followed by remote radiotherapy. The method of “absence of tumor cells” at the edges of resection demonstrated a high percentage of 1, 3, 5-year relapse - free and overall survival, the frequency of relapse was 2.6%. There was no statistically significant difference in 1, 3, 5-year relapse-free and overall survival when the width of the resection edges was more or less than 1 mm. Conclusion. The results of numerous studies have demonstrated that the breast- conserving surgery is the safe method of surgical treatment from an oncological point of view and is an alternative for radical mastectomies for patients with the breast cancer after neoadjuvant chemotherapy.

A modified unsharp masking with adaptive threshold and objectively defined amount based on saturation constraints

Unsharp Masking (UM) is a popular technique widely used for sharpening medical imagery. However, UM has two operational parameters which have crucial influence on its performance. They are amount (λ) and threshold (α). Improper selection of the threshold and amount will cause noise amplification and overshoot artefact, respectively. A fully adaptive UM with data driven operational parameters, for sharpening Magnetic Resonance (MR) images is proposed in this paper. The proposed sharpening scheme is compared with the homomorphic filter in terms of sharpness of the output image, width of salient edges, feature preservation, saturation and edge quality degradation due to noise. The proposed scheme of UM is found to be superior to homomorphic filter in terms of edge strength and feature preservation and it is free from overshoot artefacts. Modified configuration of UM, proposed in this paper can be used for improving the edge quality of MR images. It can be incorporated as a plug-in in software tools used for the automated analysis of MRI.

A prospective case study of high boost, high frequency emphasis and two-way diffusion filters on MR images of glioblastoma multiforme.

Glioblastoma multiforme (GBM) appears undifferentiated and non-enhancing on magnetic resonance (MR) imagery. As MRI does not offer adequate image quality to allow visual discrimination of the boundary between GBM focus and perifocal vasogenic edema, surgical and radiotherapy planning become difficult. The presence of noise in MR images influences the computation of radiation dosage and precludes the edge based segmentation schemes in automated software for radiation treatment planning. The performance of techniques meant for simultaneous denoising and sharpening, like high boost filters, high frequency emphasize filters and two-way anisotropic diffusion is sensitive to the selection of their operational parameters. Improper selection may cause overshoot and saturation artefacts or noisy grey level transitions can be left unsuppressed. This paper is a prospective case study of the performance of high boost filters, high frequency emphasize filters and two-way anisotropic diffusion on MR images of GBM, for their ability to suppress noise from homogeneous regions and to selectively sharpen the true morphological edges. An objective method for determining the optimum value of the operational parameters of these techniques is also demonstrated. Saturation Evaluation Index (SEI), Perceptual Sharpness Index (PSI), Edge Model based Blur Metric (EMBM), Sharpness of Ridges (SOR), Structural Similarity Index Metric (SSIM), Peak Signal to Noise Ratio (PSNR) and Noise Suppression Ratio (NSR) are the objective functions used. They account for overshoot and saturation artefacts, sharpness of the image, width of salient edges (haloes), susceptibility of edge quality to noise, feature preservation and degree of noise suppression. Two-way diffusion is found to be superior to others in all these respects. The SEI, PSI, EMBM, SOR, SSIM, PSNR and NSR exhibited by two-way diffusion are 0.0016 ± 0.0012, 0.2049 ± 0.0187, 0.0905 ± 0.0408, 2.64 × 1012 ± 1.6 × 1012, 0.9955 ± 0.0024, 38.214 ± 5.2145 and 0.3547 ± 0.0069, respectively.

Degradation of adhesion between Cu and epoxy-based dielectric during exposure to hot humid environments

Degradation of adhesion between Cu and epoxy-based dielectric build-up film (EDF), which is used for fan-out wafer level packaging applications, was investigated by the reliability test. The samples were composed of four layers: epoxy molding compound substrate, laminated EDF, electroless Cu, and electrolytic Cu. Adhesion was evaluated by the 90° peel test before and after the temperature and humidity (T&H) test and the highly accelerated temperature and humidity stress test (HAST). The effects of the peel strip width and humidity exposure of the peeled edges on adhesion were determined. It was found that adhesion gradually decreased during the reliability tests. The adhesion reduction mechanism was explained by the combinatorial effect of the loss in chemical bonding and the degradation of mechanical interlocking due to moisture. A black strip was observed along the edges of the peeled Cu strips (herein referred to as the black band, BB). AES revealed the BB as the superficial oxidation of the Cu strip. HAST and the T&H test showed the effect of the BB in an additional adhesion loss. SEM revealed a local cohesive fracture of the polymer, which led to an additional loss due to an early failure of the degraded polymer. Furthermore, BB growth showed a linear correlation with the square root of time and was accompanied with adhesion reduction. Since the modern packages have micro-sized Cu lines, the formation of BB should be avoided for better reliability of devices.

The optimization of channels for a proton exchange membrane fuel cell applying genetic algorithm

A channel is a significant part of a proton exchange membrane fuel cell (PEMFC), and the configuration of the channel has a great effect on the mass transfer of the PEMFC, which directly influences the performance. In this study, a three-dimensional, single-phase, and non-isothermal model of a PEMFC with a single straight channel is developed. Based on the model, genetic algorithm (GA) is adopted to obtain an optimal design of the channel configuration. Power consumption of flow and output power of a PEMFC are considered into the objective function, and the width of bottom and top edges of the channel, in both the anode and cathode sides, are selected as variables. The optimal design obtained is a trapezoidal channel. At an operating potential of 0.4V, the increment in current density in the optimal design is 10.92% compared to a basic design having a square channel. Moreover, the optimal design shows more uniform distributions of reactants and current density than the basic design.

Graphene nanoribbons anchored to SiC substrates

Graphene nanoribbons are quasi-one-dimensional planar graphene allotropes with diverse properties dependent on their width and types of edges. Graphene nanoribbons anchored to substrates is a hybrid system, which offers novel opportunities for property modifications as well as experimental control. Here we present electronic structure calculations of zigzag graphene nanoribbons chemically attached via the edges to the Si or C terminated surfaces of a SiC substrate. The results show that the edge characteristics are rather robust and the properties are essentially determined by the individual nanoribbon. While the localized spin polarization of the graphene nanoribbon edge atoms is not significantly affected by the substrate, secondary energy gaps in the highest conduction and lowest valence region may emerge in the anchored structures. The van der Waals interaction together with the electrostatic interactions due to the polarity of the surface bonds are found to be important for the structure parameters and energy stability.

Forest edges in managed riparian forests in the eastern part of the Czech Republic

Forest edges usually possess unique composition and characteristics compared to interior forests. Knowledge of the width of the forest edges and their attributes are important in support of forest management as well as conservation decisions. However, in European deciduous forests, little information is available on the extent of this phenomenon. We have assessed the extent and magnitude of the forest edge effect on the stand structure and tree characteristics in managed riparian forests in the Czech Republic. We measured diameter at breast height (DBH), tree height, height of the first green branch, tree tilt and hollows in stems in 50 transects and subsequently calculated stand descriptors such as basal area, tree density, crown length ratio, and slenderness ratio. We also assessed natural regeneration and a shrub cover. The results support existence of a clear threshold between forest edge and forest interior conditions for all variables but proportion of trees with hollows and trees leaning to interior. The width of the forest influenced by proximity to forest edge was found to be between 4 and 18m, with an average width of 8m. Density of natural regeneration remained constant for the first 15m and then declined farther into the interior. Shrub coverage declined steadily with the increasing distance from the forest edge. The distance from forest edge had significant negative effect on basal area and standing volume, while it had a positive effect on the proportion of straight trees, and slenderness ratio. We propose that an 8m wide forest edge may be excluded from intensive forest management as it possesses inferior stand characteristics from a timber production point of view. At the same time, it shows some characteristics desirable for species conservation such as presence of large trees with capacity for snag recruitment and high shrub cover. Sufficient natural regeneration we observed further indicates capacity for persistence in the future. Forest edges in temperate riparian forests may thus be suitable candidate areas where conservation could be the primary objective of the forest management.

Analysis of Graphene Nanoribbons Passivated with Gold, Copper and Indium

This study investigates the effect of edge- passivation on graphene nanoribbons. The geometry of graphene is simple and regular, and infinite, planar structure can easily be created either by hand or by taking a single layer from the crystal structure of graphene. To create a device-like structure, the infinite sheet must be cut into a suitable shape. Such a shape, at least for electronic applications, and it is called graphene nanoribbon (GNR). A pristine graphene monolayer can be cut into elongated strips to form 1D structure, referred to as graphene nanoribbons (GNRs) which can be either metallic or semiconducting depending on the type and width of edges. On the base of series of simulations it is found that elements from Ist, IIIrd and IV th group are used as passivated elements with Armchair and Zigzag nanoribbons instead of Hydrogen. Best characteristics for zigzag nanoribbons are presented by elements from Ist group. All experiments are made with Gold and Copper. For armchair nanoribbons, best characteristic are shown by elements from III rd group. The experiment is made with Indium. For nanoribbon with zigzag shaped edge is used DFT (Density Functional Theory) with LDA (Local Density Approximation). The chiral index of such nanoribbon is (3, 3). For the calculations of armchair nanoribbon is used Extended Huckel method. The chiral index of such nanoribbon is (3, 0). In both cases the k-point are set to 1 x 1 x 100 for na, nb and nc, respectively. For nanoribbons with zigzag shaped edges, DFT calculations show that edge-state bands at Fermi level (EF) rise to a very large Density of States (DOS) at EF, while Density of States of the armchair nanoribbons shows an energy gap around Fermi level. After Band Structure and Density of State, Bloch State is calculated and plot. Bloch States can be used to investigate the symmetry of certain bands and how this may be releated to the transport properties. Looking at the respective Bloch function, the wave function at G and Z are real and there is a distinct difference between valence and conduction band Bloch functions. These findings can be useful for the prospective GNR-based devices.

Contrasting effect of isolation of hedges from forests on farmland vs. woodland birds

Hedges and forest edges play a major role in providing nesting sites, food resources and shelter for birds in agricultural landscapes of western and central Europe. We investigated the response of farmland vs. woodland birds at two degrees of isolation of hedges from forest and to vegetation structure. We surveyed 200 m long sections of six forest edges, six hedges connected to forests and six isolated hedges. Species richness and abundance of farmland birds were higher in hedges than in forest edges, species richness and abundance of woodland birds were lower in hedges than in the forest edges. Species richness and abundance of both groups did not differ between connected and isolated hedges. Width and height of hedges and edges did not affect the species richness and abundance of either farmland or woodland birds. Furthermore, bird community composition differed between habitat types (hedge vs. forest edge) and also between hedge isolation levels (hedges connected to forest vs. isolated hedges). Based o...

Clinal pattern of morphological variation in Sakesphorus luctuosus (Lichtenstein, 1823), with comments on the enigmatic Sakesphorus hagmanni Miranda-Ribeiro, 1927 (Passeriformes: Thamnophilidae)

Sakesphorus luctuosus (Glossy Antshrike) is endemic to Brazil, harboring two subspecies. The nominal subspecies is widespread in the Amazon region, and S. l. araguayae is endemic to the Rio Araguaia valley. In this paper we investigated the hypothesis that S. l. araguayae represents the end of a cline. We examined 588 specimens housed in Brazilian, North American and European museums and based our conclusions on plumage coloration and morphometric characters. We found no significant differences in morphometric characters between subspecies, except for culmen length, which was slightly shorter in S. l. araguayae, but with wide overlap in measurements. The main proposed diagnostic character between subspecies (length of the white tips to tail feathers) showed clinal variation, with northern birds showing more white on the tail, and southern birds showing less white on the tail, irrespective of hydrographic basin. The other diagnostic character proposed (width of the white edges to the outer webs of the scapular feathers) showed high individual variation and no taxonomic consistency. We conclude that S. l. araguayae is a junior synonym of the nominal taxon. On the other hand, S. hagmanni, known only from the holotype and long thought to be a junior synonym of the nominal taxon, proved to be a unique specimen that should be considered as species inquirenda until further investigations determine its status.

Bold graph drawings

When a graph is drawn in a classical manner, its vertices are shown as small disks and its edges with a positive width; zero-width edges and zero-size vertices exist only in theory. Let r denote the radius of the disks that show vertices and w the width of edges. We give a list of conditions that make such a drawing good and that apply to not necessarily planar graphs. We show that if r < w , a vertex must have constant degree for a drawing to satisfy the conditions, and if r ⩾ w , a vertex can have any degree. We also give an algorithm that, for a given drawing and values for r and w, determines whether the bold drawing satisfies the conditions. Furthermore, we show how to maximize r and/or w without violating the conditions in polynomial time.

Pathological and clinical features of cystic and noncystic glioblastomas

The aim of this study is to review the different histological and clinical characteristics of glioblastoma multiforme (GBM) with and without cysts (cystic and noncystic GBM, respectively). Thirty-seven GBM were collected; these were tumors for which more than 80% of the volume was surgically resected, including a portion of the peripheral parenchyma of the brain. Based on preoperative magnetic resonance (MR) imaging studies, tumors were tentatively classified as cystic GBM if more than 50% of their volume appeared to be liquid; otherwise, they were considered to be noncystic GBM. Tumor volumes were estimated from contrast-enhanced T1-weighted MR images. Edema was deduced from the maximum width of contrast-enhanced edges. Peritumoral pathological analysis showed distinct margins, indicating little or no infiltration of tumor cells into white matter. Five cases were classified as cystic and 32 were noncystic GBMs. There was a statistically significant difference in age (Mann-Whitney U test; P < 0.05) between the patients with cystic tumors (median, 44 years; range, 26-59 years) and those with noncystic tumors (median, 54 years; range, 26-81 years). Four of the cystic tumors and eight of the noncystic tumors were more than 5 cm in maximum diameter. Cystic GBMs had a well-defined tumor interface and less than 2-cm-thick peritumoral edema compared to the noncystic GBMs (Fisher's exact test; P < 0.05). For patients with cystic GBMs, median survival time after surgery was 19.8 months and the 2-year survival rate was 50%. Patients with noncystic GBMs had a median survival time of 12.8 months and a 2-year survival rate of only 17%. Median time to tumor recurrence was 13.3 months for patients harboring cystic GBMs and 8.5 months for those with noncystic GBMs (log-rank test; P < 0.05). Thus, the prognosis for cystic GBM was significantly better than that for noncystic GBM, possibly because cystic GBMs showed comparatively little infiltration of the peritumoral brain parenchyma.

Unsprayed field margins: effects on environment, biodiversity and agricultural practice

A management strategy developed for field margins to reduce pesticide drift to non-target areas and to promote biodiversity on arable land was investigated. It involved not spraying herbicides and pesticides in a strip 3 or 6 m wide on the edges of winter wheat, sugar beet and potato crops. This strategy was compared with spraying the edges. The effects on pesticide drift, arable flora, invertebrates, vertebrates, costs and acceptance by the farmer were studied. This article reviews the most important results. Interviews with farmers showed that field margins were sprayed intensively. Drift measurements demonstrated that creating unsprayed buffer zones of 3 m width is a very effective way of reducing pesticide drift to the ditches demarcating the field (drift is reduced by about 95%) and risks to aquatic organisms. The presence and abundance of plants associated with arable farming increased substantially in the unsprayed edges, as did the floristic value of the vegetation. The impact on epigeic soil invertebrates was relatively minor. However, there was a pronounced effect on phytophage insects. The number of visits to the unsprayed edges by Motacilla flava flava, an insectivorous bird, also increased. A cost-benefit analysis based on the yield losses showed that it is very feasible to incorporate unsprayed crop edges in the cultivation of winter wheat and potatoes. In sugar beet, however, the cost is too high. However, for reasons to do with agronomy, farming equipment and socio-psychology, farmers will accept unsprayed cereal edges or grass strips but not unsprayed potato edges. From their perspective the most important aspect for acceptance in farming practice is a flexible width of the unsprayed crop edges.

Microstrain characterization of metals using high-resolution neutron diffraction

Two neutron diffraction arrangements were used for the investigation of residual microstrains in metals. A high instrumental resolution was reached exploiting the neutron-optical properties of bent perfect Si crystals; Δd/ d = 2.6 × 10 −3 for the three-axis arrangement and Δd/ d = 8 × 10 −4 in the case of energy-dispersive transmission diffraction geometry. Low-carbon steel subjected to small tensile prestrains was tested by using both instruments. Microstrain distribution was deduced from the width and shape of Bragg diffraction peaks and edges, respectively.

The relationship between lip shapes and acoustical characteristics during speech

This paper studied recognition tests jointly using articulatory behavior of lips and sound pattern during speech. Lip movements were monitored by using a high-speed video system with a frame rate of 5 ms. At the same time, speech sounds were recorded on a digital recorder. Two parameters, lip opening area and width of lip edges, were obtained as a time pattern from approximated contours with a fourth-degree polynomial [ICSLP90, 11.6.1 (1990)]. Recognition tests were examined by using acoustical parameters of three formant patterns (F1, F2, andF 3), as well as articulatory parameters. The speech materials used in the paper were nonsense words of symmetrical form |eCVCe| (V: a, i, u, e, o; C: p, b, m) from four males. A neural network was used for recognition tests of identifying (1) morae (CV), (2) vowel (V), and (3) consonant (C) from the time patterns of articulatory movements and acoustical sounds in –CVC–. The recognition rate of vowels using both articulatory and acoustical patterns was 91%, and it was higher than that using these patterns separately. In recognition of the consonant test, the score uisng the shape pattern was 96%, and it was higher than that using both acoustical and shape patterns.

Effects of even-aged management on forest birds at northern hardwood stand interfaces

Breeding birds were counted along transects across edges of even-aged northern hardwood stands in the White Mountain National Forest, New Hampshire, U.S.A. Two replicate transects across each of 7 edge types representing 3 classes of contrast (abrupt, intermediate, and subtle) were sampled during June 1983–1985 to define species assemblages at stand edges and estimate the width and longevity of functional edges under even-aged management. Of 52 bird species, 28 occurred across all three classes of edges, but no unique species or assemblages were evident at the edges between stands. Across edges between young stands, bird species richness declined linearly from seedling stand interior to pole stand interior, but no differences in cumulative bird species richness by edge contrast type were found. The proportion of edge-detected species was higher in the younger stand in all edge contrast types except the most subtle edge type between mature stands. Only across seedling-sawlog and sapling-large sawlog edges were bird assemblages more different than similar. Edge “avoidance” was pronounced when stands were most different. The distributions of foraging and nesting guilds differed ( P < 0.05) only when seedling or sapling stands abutted stands that were pole-sized, or larger. Edges between even-aged northern hardwood stands, even of greatly contrasting age or height, are different from field-forest edges. Northern hardwood clearcuts regenerate rapidly and do not develop a grass stage nor a brushy border. Foliage profiles in stands of widely disparate ages are similar, and effects of boundaries between even-aged stands on breeding birds are ephemeral.