Periareolar reduction mammaplasty

This paper examines the technique of periareolar reduction mammaplasty. Periareolar reduction mammaplasty is a less aggressive procedure than traditional techniques. It preserves a greater number of central glandular lobules, as well as the papillary artery and nerve. It can be performed under local anesthesia, and the area to be anesthetized is smaller because the amount of breast tissue to be resected is reduced. The sutures required number less than a third of those used for conventional techniques, and operative time is shorter. The greatest advantage is the inconspicuous periareolar scar left, combined with an acceptable result for both surgeon and patient.     

"Zigzag" wavy-line periareolar incision

There is almost no mention of improvement in the aesthetics of areolar incisions in the plastic and reconstructive surgery literature. The most visible area of the breast is the central mound; therefore, it behooves surgeons to make an areolar incision as inconspicuous as possible. Minimal incision breast operations and short-scar operations, such as mastopexy and vertical reduction mammaplasty, use a circumareolar incision. This circumareolar technique, which specifically avoids a purse-string support suture, is useful in all periareolar incisions. This method creates a scar that mimics the elusive, natural irregularity between the areola and periareolar skin. The goal is to have an irregular, random, wavy line that appears more natural. Between August of 1998 and August of 1999, 104 "zigzag" wavy-line procedures were performed. The complications seen in this series included delayed healing in four patients and hypertrophic scar in two patients. No scars were surgically revised. The results demonstrated a definite difference compared to a circular scar. The zigzag wavy-line technique complements the innovative methods that shorten scars while they create a more natural, lasting breast mound. For areolar incisions, good results are deceptively subtle, but unnatural results can be painfully obvious. The zigzag wavy-line incision subtly eludes the eye in diminishing the signs the patient has undergone an operation.     

The medial periareolar approach to submuscular augmentation mammaplasty under local anesthesia

The medial approach to submuscular augmentation mammaplasty under local anesthesia begins with a medial periareolar incision around one-half or more of the areola. A subcutaneous tunnel is made toward the medial breast border, avoiding mammary ducts and sensory nerves to the nipple. The breast is reflected laterally, exposing a patch of pectoralis major muscle. A submuscular pocket is then created beneath portions of the pectoralis major, rectus abdominis, external oblique abdominis, and serratus anterior muscles, after which the implant is inserted and the muscle, dermis, and skin are closed sequentially. The periareolar incision allows for favorable scars without compromising the access or exposure necessary for accurate implant placement. Complete muscle coverage of the implant should contribute to a lower rate of capsular contracture. With a medial submuscular approach, nipple sensation is rarely altered, and revisions, if necessary, can be done through the same incision, still under local anesthesia, for increased safety, economy, and convenience. The medial approach to breast augmentation is a highly versatile, safe, and consistent method of achieving excellent results in breast augmentation in terms of scar, symmetry, and softness.     

Intracapsular allogenic dermal grafts for breast implant-related problems

Despite advances in surgical techniques and breast implant design, certain problems unique to breast implant surgery remain. The historically most onerous problem, capsular contracture, is relatively uncommon now. However, problems related to thin capsules and periprosthetic atrophy are becoming more common; these problems include rippling, symmastia, implant malposition, and bottoming out. Options for treatment of these conditions remain extremely limited, particularly with saline implants. Allogenic dermal grafting provides one satisfactory option. Techniques for use of allogenic dermal grafts and early results from 10 patients are summarized in this article, along with histologic analysis confirming viability of the grafts at 6-month follow-up in one patient. No graft-related complications were identified.     

The role of prey availability in aggregative behaviour of the orb weaving spider Tetragnatha elongata

Like many spider species, Tetragnatha elongata exhibits considerable flexibility in its spacing pattern as a response to variable levels of prey abundance. This study examines the extent and form of spider aggregation at high prey density. In experiments in which their respective densities were manipulated, when spider density was high, excess prey allowed individuals (1) a significant reduction in web building, and (2) indiscriminate use of pre-laid silk. These effects were not observed at low spider density. These results are discussed in the context of ‘risk-sensitive’ foraging theory, which shows how this type of behaviour in an aggregation might be adopted as a means for reducing resource variance. Such an approach indicates a possible means through which sociality might be initiated.     

For flux's sake: General considerations for energy‐flux calculations in ecological communities

Global change alters ecological communities with consequences for ecosystem processes. Such processes and functions are a central aspect of ecological research and vital to understanding and mitigating the consequences of global change, but also those of other drivers of change in organism communities. In this context, the concept of energy flux through trophic networks integrates food‐web theory and biodiversity‐ecosystem functioning theory and connects biodiversity to multitrophic ecosystem functioning. As such, the energy‐flux approach is a strikingly effective tool to answer central questions in ecology and global‐change research. This might seem straight forward, given that the theoretical background and software to efficiently calculate energy flux are readily available. However, the implementation of such calculations is not always straight forward, especially for those who are new to the topic and not familiar with concepts central to this line of research, such as food‐web theory or metabolic theory. To facilitate wider use of energy flux in ecological research, we thus provide a guide to adopting energy‐flux calculations for people new to the method, struggling with its implementation, or simply looking for background reading, important resources, and standard solutions to the problems everyone faces when starting to quantify energy fluxes for their community data. First, we introduce energy flux and its use in community and ecosystem ecology. Then, we provide a comprehensive explanation of the single steps towards calculating energy flux for community data. Finally, we discuss remaining challenges and exciting research frontiers for future energy‐flux research.     

Quantifying the interaction structure and the topological importance of species in food webs: A signed digraph approach

Due to the structural complexity of nature, it is not always easy to identify topologically importance species in an ecosystem. In the past decade, several studies in ecology have developed methods for measuring species importance basing on direct and indirect inter-specific interactions. Here, by extending a previously developed methodology, we present an approach that can quantify the interaction structure of a food web and consequently the topological importance of species when the food web is viewed as a signed digraph. The basic principle behind our approach is to determine the sign and strength of direct and indirect interactions for all pathways up to a predefined number of steps. Our approach mainly differs from the previous methodology in that we are able to quantify the strength of inter-specific interaction as well as in what way species interact with each other, as it can explicitly quantify a wide range of ecological interactions such as cascading effect, indirect food supply effect, apparent and exploitive competitions in the same framework. This then allows us to quantify the topological importance of a species and examine whether it is a predominately positive or negative interactor in a food web. Furthermore, our analysis reveals that positive and negative effects from one species on others eventually cancel each other out for longer pathways resulting in stable interaction structure. Applications of our methodology include providing a more informative index for conservation biologists, and the potential use of interaction structure derived from our approach in food web robustness studies is also discussed.     

Correction of inverted nipple with periductal fibrous flaps.

I devised a method to correct the inverted nipple considering the preservation of the lactiferous ducts, sensory fibers to the nipple, and the contracting function of the areolar muscle. Excision of the excess skin at the base of the nipple was done in three diamonds fashion, and they were located at 2, 6, and 10 o'clock positions not to jeopardize the sensory fibers to the nipple. To release the fastened nipple, the periductal fibrous tissue was thoroughly dissected and made into three flaps pedicled inferiorly. These three flaps were sutured to the dermis of the periareolar skin to pull up the nipple base by means of traction in three directions. The purse-string suture, the dermal stitch on the shorter diagonals of the diamond-shaped defects, anchors the skin-muscle bridges caught at the base of the ductal column, makes the nipple base narrower, obtains stable anchoring, helps the areolar muscle contraction to resume, and prevents the recurrence of the inversion. The use of the periductal tissue as flaps to bring in areolar skin for easier anchoring and for more prominent eversion of the nipple has not been described in the literature.     

A Z-mammaplasty with minimal scarring

An improved technique for reduction mammaplasty is described that has the advantage of giving a satisfactory final shape to the breast while producing a minimal scar. The method involves periareolar deepithelialization with displacement of the nipple-areola complex, partial subcutaneous mastectomy at the base of the mammary cone, and a Z-plasty to interlock two triangles of skin left after the removal of a little excess skin in the region above the inframammary fold. The Z-plasty adds skin vertically to the inferior pole, resulting in a better final shape and reducing tension around the areola. Any further excess skin is left to retract spontaneously. The best indications for this operation are in young women with elastic skin free of striae "gravidarum." Our experience now covers 53 patients aged 14 to 30 years with reductions of up to 900 gm per breast, and we have encountered no major complications over a 3-year follow-up period.     

Reduction mammaplasty with the "owl" incision and no undermining

Reduction mammaplasty has traditionally been done using the Wise pattern of incision. Because of the box-like effect in breast shape, the lack of projection, and the long scars associated with the inverted T incision, two techniques have emerged as alternatives: the vertical reduction of Lassus/Lejour and the "round block" periareolar technique popularized by Benelli. Each of these techniques has its pros and cons.The "owl" incision combines the features of the large periareolar reduction (Benelli's) and the vertical reduction (Lassus/Lejour); the horizontal inframammary scar is either made very short or completely eliminated. Volume reduction is done through a heart-shaped parenchymal resection, leaving the nipple-areolar complex over a supero-central pedicle. Maintenance of the central parenchyma behind the nipple-areolar complex and mobilization of the vertical pillars toward the center of the breast give excellent projection and diminish the lateral fullness. Enlargement of the periareolar skin resection diminishes the length and pleating of the vertical scar; conversely, inclusion of the vertical component to the periareolar technique eliminates the pleating effect of the periareolar incision. The short horizontal excision eliminates any resultant "dog ears" in the new inframammary fold. Thus, the discrepancy in the length of scars is better distributed. There is no skin or parenchymal undermining, so drains are not needed. Excellent results are obtained immediately on the operating table, and large volumes of glandular resection and correction of severe ptosis can be accomplished without compromising vascularity of either the nipple-areolar complex or the skin flaps.Ninety-four patients in a 7-year period were operated upon using this technique. Seventy-two had bilateral reductions up to 1900 gm per breast, 12 had unilateral reduction for symmetry following breast reconstruction, and 10 were patients with severe ptosis. Complications were rare and of a minor nature. No conversion to free grafts was done, even in the larger resections. One case required minor revision under local anesthesia, one case required bilateral re-reduction, and another case required unilateral re-reduction for continued growth of breast tissue. Almost 90 percent of the patients underwent procedures as outpatients.The owl-type incision and the supero-central pedicle flap are elements of a reduction mammaplasty technique that provides excellent projection and shape with minimal visible scars. It takes advantage of the positive features of the periareolar and vertical reduction techniques and minimizes their negative features. The new design of parenchymal resection improves the vascularity of the residual flaps. Additionally, it may better preserve the sensation to the nipple-areolar complex and lactation is not compromised.     

Explicit Tracking of Uncertainty Increases the Power of Quantitative Rule-of-Thumb Reasoning in Cell Biology

Back-of-the-envelope or rule-of-thumb calculations involving rough estimates of quantities play a central scientific role in developing intuition about the structure and behavior of physical systems, for example in so-called Fermi problems in the physical sciences. Such calculations can be used to powerfully and quantitatively reason about biological systems, particularly at the interface between physics and biology. However, substantial uncertainties are often associated with values in cell biology, and performing calculations without taking this uncertainty into account may limit the extent to which results can be interpreted for a given problem. We present a means to facilitate such calculations where uncertainties are explicitly tracked through the line of reasoning, and introduce a probabilistic calculator called CALADIS, a free web tool, designed to perform this tracking. This approach allows users to perform more statistically robust calculations in cell biology despite having uncertain values, and to identify which quantities need to be measured more precisely to make confident statements, facilitating efficient experimental design. We illustrate the use of our tool for tracking uncertainty in several example biological calculations, showing that the results yield powerful and interpretable statistics on the quantities of interest. We also demonstrate that the outcomes of calculations may differ from point estimates when uncertainty is accurately tracked. An integral link between CALADIS and the BioNumbers repository of biological quantities further facilitates the straightforward location, selection, and use of a wealth of experimental data in cell biological calculations.     

Towards autonomic performance management of large scale data centers using interaction balance principle

In this paper, an autonomic performance management approach is introduced that can be applied to a general class of web services deployed in large scale distributed environment. The proposed approach utilizes traditional large scale control-based algorithms by using interaction balance approach in web service environment for managing the response time and the system level power consumption. This approach is developed in a generic fashion that makes it suitable for web service deployments, where web service performance can be adjusted by using a finite set of control inputs. This approach maintains the service level agreements, maximizes the revenue, and minimizes the infrastructure operating cost. Additionally, the proposed approach is fault-tolerant with respect to the failures of the computing nodes inside the distributed deployment. Moreover, the computational overhead of the proposed approach can also be managed by using appropriate value of configuration parameters during its deployment.     

High performance web server architecture with Kernel-level caching

In this work we are focusing on reducing response time and bandwidth requirements for high performance web server. Many researches have been done in order to improve web server performance by modifying the web server architecture. In contrast to these approaches, we take a different point of view, in which we consider the web server performance in OS perspective rather than web server architecture itself. To achieve these purposes we are exploring two different approaches. The first is running web server within OS kernel. We use kHTTPd as our basis for implementation. But it has a several drawbacks such as copying data redundantly, synchronous write, and processing only static data. We propose some techniques to improve these flaws. The second approach is caching dynamic data. Dynamic data can seriously reduce the performance of web servers. Caching dynamic data has been thought difficult to cache because it often change a lot more frequently than static pages and because web server needs to access database to provide service with dynamic data. To this end, we propose a solution for higher performance web service by caching dynamic data using content separation between static and dynamic portions. Benchmark results using WebStone show that our architecture can improve server performance by up to 18 percent and can reduce user’s perceived latency significantly.     

Food-web studies in shallow eutrophic lakes by the Netherlands Institute of Ecology: Main results,knowledge gaps and new perspectives

For more than 20 years scientists of the ‘Food-chain studies’ Group of the former Limnological Institute have been studying interactions within the pelagic food web. Purpose of research was to explain the structure and dynamics of the zooplankton and fish communities in lakes and reservoirs in relation to biotic and abiotic environmental factors. A so-called multi-species approach was used, in which all common and abundant species within a specific ecosystem were studied on the individual and population level with the same degree of detail. The recent results and the scientific approach used are evaluated and the main gaps in knowledge about food-web dynamics in shallow eutrophic lakes are identified and discussed. It is concluded that instead of the purely functional approach used so far, future studies should also include evolutionary aspects which determine the success of an organism in a given environment and that more attention should be paid to central questions in ‘community ecology’. This paper is based on a lecture given by the first author for the Netherlands Society of Aquatic Ecology on May 12th, 1992, in Amsterdam, The Netherlands.     

Automatic cell counting with ImageJ

Cell counting is an important routine procedure. However, to date there is no comprehensive, easy to use, and inexpensive solution for routine cell counting, and this procedure usually needs to be performed manually. Here, we report a complete solution for automatic cell counting in which a conventional light microscope is equipped with a web camera to obtain images of a suspension of mammalian cells in a hemocytometer assembly. Based on the ImageJ toolbox, we devised two algorithms to automatically count these cells. This approach is approximately 10 times faster and yields more reliable and consistent results compared with manual counting.     

Predator hunting mode influences patterns of prey use from grazing and epigeic food webs

Multichannel omnivory by generalist predators, especially the use of both grazing and epigeic prey, has the potential to increase predator abundance and decrease herbivore populations. However, predator use of the epigeic web (soil surface detritus/microbe/algae consumers) varies considerably for reasons that are poorly understood. We therefore used a stable isotope approach to determine whether prey availability and predator hunting style (active hunting vs. passive web-building) impacted the degree of multichannel omnivory by the two most abundant predators on an intertidal salt marsh, both spiders. We found that carbon isotopic values of herbivores remained constant during the growing season, while values for epigeic feeders became dramatically more enriched such that values for the two webs converged in August. Carbon isotopic values for both spider species remained midway between the two webs as values for epigeic feeders shifted, indicating substantial use of prey from both food webs by both spider species. As the season progressed, prey abundance in the grazing food web increased while prey abundance in the epigeic web remained constant or declined. In response, prey consumption by the web-building spider shifted toward the grazing web to a much greater extent than did consumption by the hunting spider, possibly because passive web-capture is more responsive to changes in prey availability. Although both generalist predator species engaged in multichannel omnivory, hunting mode influenced the extent to which these predators used prey from the grazing and epigeic food webs, and could thereby influence the strength of trophic cascades in both food webs.     

Exploring the temporal variability of a food web using long‐term biomonitoring data

Ecological communities are constantly being reshaped in the face of environmental change and anthropogenic pressures. Yet, how food webs change over time remains poorly understood. Food web science is characterized by a trade‐off between complexity (in terms of the number of species and feeding links) and dynamics. Topological analysis can use complex, highly resolved empirical food web models to explore the architecture of feeding interactions but is limited to a static view, whereas ecosystem models can be dynamic but use highly aggregated food webs. Here, we explore the temporal dynamics of a highly resolved empirical food web over a time period of 18 years, using the German Bight fish and benthic epifauna community as our case study. We relied on long‐term monitoring ecosystem surveys (from 1998 to 2015) to build a metaweb, i.e. the meta food web containing all species recorded over the time span of our study. We then combined time series of species abundances with topological network analysis to construct annual food web snapshots. We developed a new approach, ‘node‐weighted’ food web metrics by including species abundances to represent the temporal dynamics of food web structure, focusing on generality and vulnerability. Our results suggest that structural food web properties change through time; however, binary food web structural properties may not be as temporally variable as the underlying changes in species composition. Further, the node‐weighted metrics enabled us to detect that food web structure was influenced by changes in species composition during the first half of the time series and more strongly by changes in species dominance during the second half. Our results demonstrate how ecosystem surveys can be used to monitor temporal changes in food web structure, which are important ecosystem indicators for building marine management and conservation plans.     

Methods for facilitating web-based participatory research informatics

Scientific datasets are often generated and used by “communities”, or groups of users and creators. These communities, today often virtual, can include researchers, decision-makers, and the general public; participants in these communities may contribute different components during various iterations in the data generation process, and have different needs for resulting data products. As this “participatory research informatics” model, which includes elements of collaborative research, public participation, and digital data libraries, becomes the norm, new approaches to dynamic data management will be important. Researchers commonly use the web as a medium for research collaboration among colleagues, as well as to disseminate results to decision-makers and the public. In addition, the web can be used to facilitate dynamic collaboration by allowing research-in-progress to be accessed and edited by multiple participants. Indeed, one key benefit of using the web to facilitate research projects is that data can undergo revisions and corrections while being displayed in some form over the web. However, it can be a challenge to keep track of multiple edits to files while maintaining the integrity of a web-interface. Here we describe a system for promoting collaboration in the creation, maintenance, and use of dynamic data over the web. Using simple Microsoft Excel spreadsheets combined with traditional relational databases to facilitate dynamic data generation and updates and maintain a data schema, we are able to facilitate efficient collaboration within and among participant communities. This approach allows for the separation of web display and content, which in turn allows participants to be responsible for their own content. This separation simplifies the interaction between those responsible for the content (researchers and other participants), those responsible for the data display (web designers), and those responsible for data management, storage, and retrieval (web programmers). The approach described here is particularly well suited to large, spatially-specific ecological datasets because it can be used to facilitate the “real-time” editing and display of visual data such as web-maps, as well as to encourage multiple participants to both contribute to and interact with “beta” data and content.     

A congruence index for testing topological similarity between trees

MOTIVATION: Phylogenetic trees are omnipresent in evolutionary biology and the comparison of trees plays a central role there. Tree congruence statistics are based on the null hypothesis that two given trees are not more congruent (topologically similar) than expected by chance. Usually, one searches for the most parsimonious evolutionary scenario relating two trees and then one tests the null hypothesis by generating a high number of random trees and comparing these to the one between the observed trees. However, this approach requires a lot of computational work (human and machine) and the results depend on the evolutionary assumptions made. RESULTS: We propose an index, I(cong), for testing the topological congruence between trees with any number of leaves, based on maximum agreement subtrees (MAST). This index is straightforward, simple to use, does not rely on parametrizing the likelihood of evolutionary events, and provides an associated confidence level. AVAILABILITY: A web site has been created that allows rapid and easy online computation of this index and of the associated P-value at http://www.ese.u-psud.fr/bases/upresa/pages/devienne/index.html     

Defining and measuring trophic role similarity in food webs using regular equivalence

We present a graph theoretic model of analysing food web structure called regular equivalence. Regular equivalence is a method for partitioning the species in a food web into "isotrophic classes" that play the same structural roles, even if they are not directly consuming the same prey or if they do not share the same predators. We contrast regular equivalence models, in which two species are members of the same trophic group if they have trophic links to the same set of other trophic groups, with structural equivalence models, in which species are equivalent if they are connected to the exact same other species. Here, the regular equivalence approach is applied to two published food webs: (1) a topological web (Malaysian pitcher plant insect food web) and (2) a carbon-flow web (St. Marks, Florida seagrass ecosystem food web). Regular equivalence produced a more satisfactory set of classes than did the structural approach, grouping basal taxa with other basal taxa and not with top predators. Regular equivalence models provide a way to mathematically formalize trophic position, trophic group and trophic niche. These models are part of a family of models that includes structural models used extensively by ecologists now. Regular equivalence models uncover similarities in trophic roles at a higher level of organization than do the structural models. The approach outlined is useful for measuring the trophic roles of species in food web models, measuring similarity in trophic relations of two or more species, comparing food webs over time and across geographic regions, and aggregating taxa into trophic groups that reduce the complexity of ecosystem feeding relations without obscuring network relationships. In addition, we hope the approach will prove useful in predicting the outcome of predator-prey interactions in experimental studies.