Life-history evolution and the polyphenic regulation of somatic maintenance and survival.

Here we discuss life-history evolution from the perspective of adaptive phenotypic plasticity, with a focus on polyphenisms for somatic maintenance and survival. Polyphenisms are adaptive discrete alternative phenotypes that develop in response to changes in the environment. We suggest that dauer larval diapause and its associated adult phenotypes in the nematode (Caenorhabditis elegans), reproductive dormancy in the fruit fly (Drosophila melanogaster) and other insects, and the worker castes of the honey bee (Apis mellifera) are examples of what may be viewed as the polyphenic regulation of somatic maintenance and survival. In these and other cases, the same genotype can--depending upon its environment--express either of two alternative sets of life-history phenotypes that differ markedly with respect to somatic maintenance, survival ability, and thus life span. This plastic modulation of somatic maintenance and survival has traditionally been underappreciated by researchers working on aging and life history. We review the current evidence for such adaptive life-history switches and their molecular regulation and suggest that they are caused by temporally and/or spatially varying, stressful environments that impose diversifying selection, thereby favoring the evolution of plasticity of somatic maintenance and survival under strong regulatory control. By considering somatic maintenance and survivorship from the perspective of adaptive life-history switches, we may gain novel insights into the mechanisms and evolution of aging.

Is ultracision knife safe and efficient for breast capsulectomy? A preliminary study.

BACKGROUND: Silicone breast implants are used to a wide extent in the field of plastic surgery. However, capsular contracture remains a considerable concern. This study aimed to analyze the effectiveness and applicability of an ultracision knife for capsulectomy breast surgery. METHODS: A prospective, single-center, randomized study was performed in 2009. The inclusion criteria specified female patients 20-80 years of age with capsular contracture (Baker 3-4). Ventral capsulectomy was performed using an ultracision knife on one side and the conventional Metzenbaum-type scissors and surgical knife on the collateral side of the breast. Measurements of the resected capsular ventral fragment, operative time, remaining breast tissue, drainage time, seroma and hematoma formation, visual analog scale pain score, and sensory function of the nipple-areola complex were assessed. In addition, histologic analysis of the resected capsule was performed. RESULTS: Five patients (median age, 59.2 years) were included in this study with a mean follow-up period of 6 months. Three patients had Baker grade 3 capsular contracture, and two patients had Baker grade 4 capsular contracture. The ultracision knife was associated with a significantly lower pain score, shorter operative time, smaller drainage volume, and shorter drainage time and resulted in a larger amount of remaining breast tissue. Histologic analysis of the resected capsule showed no apoptotic cells in the study group or control group. CONCLUSIONS: The results suggest that ventral capsulectomy with Baker grade 3 or 4 contracture using the ultracision knife is feasible, safe, and more efficient than blunt dissection and monopolar cutting diathermy and has a short learning curve. LEVEL OF EVIDENCE II: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors at www.springer.com/00266 .

Stuka (Plastyka, Muzyka): una veu a favor de l'educació a través de l'art

Traducció comentada del pròleg d¿un llibre on la seva autora, amb motiu de presentar les propostes dels seus estudiants sobre activitats integrades de plàstica i música per a l¿escola i l'institut, ens parla de la necessitat d¿activar la situació creadora en els individus per millorar el seu excel-lent procés educatiu, a la manera com ho feien els antics.

La didàctica de l'educació visual i plàstica, entre el discurs visual i el discurs estètic. La perversió del model

El presente trabajo es el resultado de un año de investigación de campo y de estudio bibliográfico, que se formalizó en un proyecto educativo dirigido a alumnos de 3 de secundaria en la área de educación visual y plástica. " Las manos" , título del proyecto, se presentó como una alternativa en la didáctica de la educación visual y plástica cuando se plantea desde un aprendizaje lineal, desde un modelo. El planteamiento consistió en potenciar la comprensión y expresión artísticas a partir de la interrelación de otras áreas de conocimiento con la visual y plástica para sensibilizar al alumno en la importancia que tiene el proceso en el acto creativo. Valorar el proceso facilitó la asimilación de conceptos como figuración, abstracción y síntesis tan importantes para entender el hecho artístico. La valoración positiva del proyecto no pretende contraponer dos metodologías diferentes: la lineal con modelos y la que se presenta en espiral, inductiva, con referentes que no tienen que ser necesariamente visuales. Las dos opciones pueden actuar en simbiosis siempre que el alumno sepa percibir el significado que quiere dar a su obra y que todo no quede en una pura representación decorativa.

Arts plàstiques i metodologia: descripció d'un model didàctic

En l'ensenyament de la plàstica, les línies pedagógiques que s'han seguit tradicionalment s'han fonamentat en el desenvolupament de la creativitat infantil, l'aprenentatge i domini de les técniques i els mitjans d'expressió i la seva relació o estudi de les arts plastiques. En general les estratégies i sistemes metodológics que s'han emprat han estat més implícits que explícits i, en moltes ocasions, desvinculats d'una visió curricular que cohesionés tots els seus components. En els darrérs anys, és quan s'ha produit el canvi més important, reconeixent el perfil disciplinari de la materia i definint-ne tant els aspectes cognitius, expressius i formatius, com la importancia de coneixer i utilitzar una metodologia didactica adient.

Cutaneous benign mixed tumor (chondroid syringoma) of the eyelid: clinical presentation and management.

PURPOSE: To describe the clinical presentation of cutaneous benign mixed tumor of the eyelid and its management options. METHODS: Periocular cases of cutaneous benign mixed tumor were gathered from members of an oculoplastics specialty Internet discussion group. A total of 9 patients are described in this retrospective, interventional case series. The clinical presentation, histopathology, and management of these lesions is reviewed. RESULTS: Patients were typically asymptomatic, presenting with a slowly enlarging, nontender nodule of 2 to 8 years' duration. The lesions ranged from 4 mm to 17 mm in greatest dimension. Four of the lesions were on the eyelid margin, three in the sub-brow area of the upper eyelid, and two in the central lids. All six cases not involving the brow were fixed to the tarsus; one brow lesion was believed to be adherent to the skin. None of the lesions was associated with significant changes of the overlying epidermis, although one lesion showed overlying pigmentation. All patients underwent excisional biopsy for diagnostic or cosmetic reasons. On histopathologic examination, the tumors were biphasic, with an epithelial component exhibiting apocrine or hair follicle differentiation and a myxoid, adipocytic, chondroid, and/or fibrous stroma. The pathologic diagnoses were all consistent with cutaneous benign mixed tumor (chondroid syringoma, pleomorphic adenoma). Follow-up ranged from 2 weeks to 12 months, although several patients failed to keep scheduled follow-up appointments. No clinical recurrences were identified. CONCLUSIONS: Cutaneous benign mixed tumor may occur in the eyelid, and, although uncommon, should be included in the differential diagnosis of firm, nodular eyelid tumors. The histopathologic features are similar to those seen in this tumor type arising in other areas of the body. Preoperative consideration of this diagnostic possibility may allow the surgeon to plan for complete excision, thereby reducing the possibility of recurrence or malignant transformation.

Iowa Pore Index Test, MLR-80-2, 1980

The objective of the investigation was the development of a test that would readily identify the potential of an aggregate to cause D-cracking because of its susceptivity to critical saturation. A Press-Ur-Meter was modified by replacing the air chamber with a one-inch diameter plastic tube calibrated in milli-. It was concluded that the pore index was sufficiently reliable to determine the D-cracking potential of limestone aggregates in all but a few cases where marginal results were obtained. Consistently poor or good results were always in agreement with established service records or concrete durability testing. In those instances where marginal results are obtained, the results of concrete durability testing should be considered when making the final determination of the D-cracking susceptibility of the aggregate in question. The following applications for the pore index test have been recommended for consideration: concrete durability testing be discontinued in the evaluation process of new aggregate sources with pore index results between 0-20 (Class 2 durability) and over 35 (Class 1) durability; composite aggregates with intermediate pore index results of 20-35 be tested on each stone type to facilitate the possible removal of low durability stone from the production process; and additional investigation should be made to evaluate the possibility of using the test to monitor and upgrade the acceptance of aggregate from sources associated with D-cracking.

The effects of arbuscular mycorrhizal fungi inoculation on Euterpe oleracea mart. (açaí) seedlings

With the objective of verifying the response of Euterpe oleracea seedlings to seven arbuscular mycorrhizal fungi species, an experimental trial was carried out under greenhouse conditions. Seeds of E. oleracea were sown in carbonized rice husk. Germinating seeds were initially transferred to plastic cups, containing fumigated Reddish Yellow Quartz Sand and inoculated with arbuscular mycorrhizal fungi. Two months later, seedlings were transferred to 2 kg black plastic bags, containing the same soil without fumigation. Plant growth and mineral nutrients were evaluated nine months after mycorrhizal inoculation. Differential effects were observed among the species tested, with Scutellispora gilmorei being the most effective ones in promoting growth and nutrient content of E. oleracea seedlings. The increment resulted from inoculation with S. gilmorei were 92% in total plant height, 116% in stem diameter, 361% in dry matter production, 191% in N, 664% in P, 46% in K, 562% in Ca, 363% in Mg and 350% in Zn contents, comparing to uninoculated controls. Infected root length was positively correlated to nutrient content and plant growth. It was concluded that growth and nutrient uptake of E. oleracea seedlings could be significantly improved by inoculation of effective arbuscular mycorrhizal fungi.

Pile Design and Tests for Integral Abutment Bridges, HR-273, 1987

Expansion joints increase both the initial cost and the maintenance cost of bridges. Integral abutment bridges provide an attractive design alternative because expansion joints are eliminated from the bridge itself. However, the piles in these bridges are subjected to horizontal movement as the bridge expands and contracts during temperature changes. The objective of this research was to develop a method of designing piles for these conditions. Separate field tests simulating a pile and a bridge girder were conducted for three loading cases: (1) vertical load only, (2) horizontal displacement of pile head only, and (3) combined horizontal displacement of pile head with subsequent vertical load. Both tests (1) and (3) reached the same ultimate vertical load, that is, the horizontal displacement had no effect on the vertical load capacity. Several model tests were conducted in sand with a scale factor of about 1:10. Experimental results from both the field and model tests were used to develop the vertical and horizontal load-displacement properties of the soil. These properties were input into the finite element computer program Integral Abutment Bridge Two-Dimensional (IAB2D), which was developed under a previous research contract. Experimental and analytical results compared well for the test cases. Two alternative design methods, both based upon the American Association of State Highway and Transportation Officials (AASHTO) Specification, were developed. Alternative One is quite conservative relative to IAB2D results and does not permit plastic redistribution of forces. Alternative Two is also conservative when compared to IAB2D, but plastic redistribution is permitted. To use Alternative Two, the pile cross section must have sufficient inelastic rotation capacity before local buckling occurs. A design example for a friction pile and an end-bearing pile illustrates both alternatives.

Relaxed selection is a precursor to the evolution of phenotypic plasticity.

Phenotypic plasticity allows organisms to produce alternative phenotypes under different conditions and represents one of the most important ways by which organisms adaptively respond to the environment. However, the relationship between phenotypic plasticity and molecular evolution remains poorly understood. We addressed this issue by investigating the evolution of genes associated with phenotypically plastic castes, sexes, and developmental stages of the fire ant Solenopsis invicta. We first determined if genes associated with phenotypic plasticity in S. invicta evolved at a rapid rate, as predicted under theoretical models. We found that genes differentially expressed between S. invicta castes, sexes, and developmental stages all exhibited elevated rates of evolution compared with ubiquitously expressed genes. We next investigated the evolutionary history of genes associated with the production of castes. Surprisingly, we found that orthologs of caste-biased genes in S. invicta and the social bee Apis mellifera evolved rapidly in lineages without castes. Thus, in contrast to some theoretical predictions, our results suggest that rapid rates of molecular evolution may not arise primarily as a consequence of phenotypic plasticity. Instead, genes evolving under relaxed purifying selection may more readily adopt new forms of biased expression during the evolution of alternate phenotypes. These results suggest that relaxed selective constraint on protein-coding genes is an important and underappreciated element in the evolutionary origin of phenotypic plasticity.

Regional Approach to Landslide Interpretation and Repair, TR-430, 2001

The objective of this report is to provide Iowa county engineers and highway maintenance personnel with procedures that will allow them to efficiently and effectively interpret and repair or avoid landslides. The research provides an overview of basic slope stability analyses that can be used to diagnose the cause and effect associated with a slope failure. Field evidence for identifying active or potential slope stability problems is outlined. A survey of county engineers provided data for presenting a slope stability risk map for the state of Iowa. Areas of high risk are along the western border and southeastern portion of the state. These regions contain deep to moderately deep loess. The central portion of the state is a low risk area where the surficial soils are glacial till or thin loess over till. In this region, the landslides appear to occur predominately in backslopes along deeply incised major rivers, such as the Des Moines River, or in foreslopes. The south-central portion of the state is an area of medium risk where failures are associated with steep backslopes and improperly compacted foreslopes. Soil shear strength data compiled from the Iowa DOT and consulting engineers files are correlated with geologic parent materials and mean values of shear strength parameters and unit weights were computed for glacial till, friable loess, plastic loess and local alluvium. Statistical tests demonstrate that friction angles and unit weights differ significantly but in some cases effective stress cohesion intercept and undrained shear strength data do not. Moreover, effective stress cohesion intercept and undrained shear strength data show a high degree of variability. The shear strength and unit weight data are used in slope stability analyses for both drained and undrained conditions to generate curves that can be used for a preliminary evaluation of the relative stability of slopes within the four materials. Reconnaissance trips to over fifty active and repaired landslides in Iowa suggest that, in general, landslides in Iowa are relatively shallow [i.e., failure surfaces less than 6 ft (2 m) deep] and are either translational or shallow rational. Two foreslope and two backslope failure case histories provide additional insights into slope stability problems and repair in Iowa. These include the observation that embankment soils compacted to less than 95% relative density show a marked strength decrease from soils at or above that density. Foreslopes constructed of soils derived from shale exhibit loss of strength as a result of weathering. In some situations, multiple causes of instability can be discerned from back analyses with the slope stability program XSTABL. In areas where the stratigraphy consists of loess over till or till over bedrock, the geologic contracts act as surfaces of groundwater accumulation that contribute to slope instability.

Validation of Design Recommendations for Integral Abutment Piles, HR-292, 1989

Since integral abutment bridges decrease the initial and maintenance costs of bridges, they provide an attractive alternative for bridge designers. The objective of this project is to develop rational and experimentally verified design recommendations for these bridges. Field testing consisted of instrumenting two bridges in Iowa to monitor air and bridge temperatures, bridge displacements, and pile strains. Core samples were also collected to determine coefficients of thermal expansion for the two bridges. Design values for the coefficient of thermal expansion of concrete are recommended, as well as revised temperature ranges for the deck and girders of steel and concrete bridges. A girder extension model is developed to predict the longitudinal bridge displacements caused by changing bridge temperatures. Abutment rotations and passive soil pressures behind the abutment were neglected. The model is subdivided into segments that have uniform temperatures, coefficients of expansion, and moduli of elasticity. Weak axis pile strains were predicted using a fixed-head model. The pile is idealized as an equivalent cantilever with a length determined by the surrounding soil conditions and pile properties. Both the girder extension model and the fixed-head model are conservative for design purposes. A longitudinal frame model is developed to account for abutment rotations. The frame model better predicts both the longitudinal displacement and weak axis pile strains than do the simpler models. A lateral frame model is presented to predict the lateral motion of skewed bridges and the associated strong axis pile strains. Full passive soil pressure is assumed on the abutment face. Two alternatives for the pile design are presented. Alternative One is the more conservative and includes thermally induced stresses. Alternative Two neglects thermally induced stresses but allows for the partial formation of plastic hinges (inelastic redistribution of forces). Ductility criteria are presented for this alternative. Both alternatives are illustrated in a design example.

Secret scar free gracilis flap.

The gracilis free flap is a workhorse in plastic surgery. We present a modified technique that relies on a single horizontal thigh-lift-type approach, which (1) gives wide pedicle exposure, (2) provides material for skin grafting, and (3) allows for distal flap transection without an additional incision. Eighteen gracilis free flaps were performed from 2007 to 2009 for lower extremity reconstruction. Complete flap survival was observed in 17 patients with one partial necrosis distally. Our approach allowed access to divide the distal gracilis tendon without a second incision in all cases. The mean scar length was 16 ± 3 cm and no hypertrophic scars were observed. In 15 patients, no visible scar was observed in the upright position, and in three patients, the scar was visible dorsally (2 ± 1 cm). No sensory deficits were observed 6 months postoperatively. In addition, the split-thickness skin graft harvested from the skin paddle was sufficient to cover all defects.

An Investigation of Concrete Setting Time, R-265 (MLR-75-4), 1975

A water reducing and retarding type admixture in concrete is commonly used on continuous bridge deck pours in Iowa. The concrete placed in the negative moment areas must remain plastic until all the dead load deflection due to the new deck's weight occurs. If the concrete does not remain plastic until the total deflection has occurred, structural cracks will develop in these areas. Retarding type admixtures will delay the setting time of concrete and prevent structural cracks if added in the proper amounts. In Section 2412.02 of the Standard Specifications, 1972, Iowa State Highway Commission, it states, "The admixture shall be used in amounts recommended by the manufacturer for conditions which prevail on the project and as approved by the engineer." The conditions which prevail on the project depend on temperature, humidity, wind conditions, etc. Each of these factors will affect the setting rate of the plastic concrete. The purpose of this project is to provide data that will be useful to field personnel concerning the retardation of concrete setting times, and how the of sets will vary with different addition rates and curing temperatures holding all other atmospheric variables constant.

Modification of Ca-Montmorillonite by Low-Temperature Heat Treatment, HR-106, 1964

Objectives of this investigation were to measure the effects of moderate heat treatments (below the dehydroxylation temperature) on physical and chemical properties of a calcium-montmorillonite clay. Previous workers have noted the reduction in cation exchange capacity and swelling property after heating in the range 200 to 400°C, and have suggested several possible explanations, such as hysteresis effect, increased inter-layer attractions due to removal of inter-layer water, or changes in the disposition of inter-layer or layer surface ions. The liquid limits of Ca-montmorillonite were steadily decreased with increased temperature of treatment, levelling at about 450°C. The plastic limit decreased slightly up to 350°C, above which samples could no longer be rolled into threads. The gradual change is in contrast with sudden major changes noted for weight loss (maximum rates of change at l00°C and 500°C), glycol retention surface area (520°C), and d001 diffraction peak intensity (17.7 A spacing) and breadth after glycolation (530°C). Other properties showing more gradual reductions with heat treatment were amount of exchangeable calcium (without water soaking), cation exchange capacity by NH4AC method, and d001 intensity (21 A spacing) after storing at 100% r.h. one month and re-wetting with water. Previous water soaking allowed much greater release of fixed Ca++ up to 450°C. Similar results were obtained with cation exchange capacities when samples were treated with N CaCl2 solution. The 21.0 A peak intensity curve showed close similarity to the liquid limit and plastic index curves in the low temperature range, and an explanation is suggested.