Home About us Contact
|
Home About us Contact | ||
|
|
||
Regrowth
Kinds of Regrowth Terms modified by Regrowth Selected AbstractsZinc Oxide Microstructures: Zinc Oxide Microtowers by Vapor Phase Homoepitaxial Regrowth (Adv. Mater.ADVANCED MATERIALS, Issue 8 20098/2009) Simultaneous axial and radial epitaxies can be achieved by growing ZnO microtowers by repeating a growth cycle several times, report Zhengwei Pan and co-workers on p. 890. The as-grown ZnO microtowers display a preferential growth habit of hexagonal prism,dihexagonal pyramid. Some rare or new growth habits such as dihexagonal prism,dihexagonal pyramid, hexagonal prism,trihexagonal pyramid and dihexagonal prism,trihexagonal pyramid (as shown on the cover) have also been identified. [source] Zinc Oxide Microtowers by Vapor Phase Homoepitaxial RegrowthADVANCED MATERIALS, Issue 8 2009Zhengwei Pan Simultaneous axial and radial epitaxies can be achieved on growing ZnO microtowers through a regrowth technique of repeating the same growth circle for several times. The as-grown ZnO microtowers display a preferential growth habit of hexagonal prism,dihexagonal pyramid. The apexes of the pyramidal towers are very sharp, with a radius of curvature as small as 2 to 50 nm. [source] Sub-millennial climate shifts in the western Mediterranean during the last glacial period recorded in a speleothem from Mallorca, Spain,JOURNAL OF QUATERNARY SCIENCE, Issue 8 2008Edward J. Hodge Abstract Very few high-resolution and directly dated terrestrial archives of the last glacial period exist for the western Mediterranean region, yet this is a key locality for recording sub-millennial North Atlantic and Mediterranean climate change. Here, we present evidence of effective precipitation changes based on growth history and ,13C of calcite in a Mallorcan stalagmite that grew between 112 and 48,ka. Effective precipitation in Mallorca appears to have been sensitive to proximal sea surface temperature variations and at certain times, ca. 76,ka for example, changed rapidly from moist to arid conditions in only a few centuries. A sea-level highstand during Marine Isotope Stage (MIS) 5a interrupted growth. Regrowth started promptly after this, but effective precipitation decreased markedly for much of the later part of MIS 5a, and also for shorter periods correlative with Heinrich events H8 (ca. 90,ka) and H6 (ca. 65,ka), with growth ceasing during H5 (ca. 48,ka). Arid episodes in Mallorca appear to be expressions of extremely cold periods recorded further north in Europe and occur contemporaneously with rapid decreases in Greenland temperature. Copyright © 2008 John Wiley & Sons, Ltd. [source] Macrophytes in Urban Stream Rehabilitation: Establishment, Ecological Effects, and Public PerceptionRESTORATION ECOLOGY, Issue 3 2006Scott T. Larned Abstract Efforts to rehabilitate degraded urban streams generally focus on improving physical habitat and rarely include reestablishing biota such as macrophytes. Our objectives in this study were to propagate and transplant native macrophytes into a South Island, New Zealand, urban stream undergoing rehabilitation, assess macrophyte survival and growth, and determine whether native macrophytes suppress non-native macrophytes and/or enhance stream invertebrate communities. Effects of native macrophytes on invertebrates and non-native macrophytes were assessed after transplanting patches of native macrophytes into a 230-m-long stream section. A 100-m-long section upstream was left unplanted for subsequent comparisons. Following the study, a survey was conducted to gauge public opinion about the rehabilitation project and determine whether macrophytes were prominent in perceptions of stream health. In the first growing season, native macrophyte cover in the planted stream section increased from 1.5 to 20%, and then decreased during winter. Regrowth from rhizomes led to rapid aboveground growth during the second year, when cover reached 51%. Non-native macrophytes colonized the stream the first year, but native macrophytes appeared to limit the spread of non-natives, which were absent in the planted section by the second spring. Native macrophyte establishment did not enhance invertebrate communities as predicted; few invertebrate metrics differed significantly between the planted and unplanted sections. Pollution- and sediment-tolerant invertebrate taxa were abundant in both sections, suggesting that invertebrate colonization was limited by water quality or sedimentation, not macrophyte composition. Survey respondents considered the stream to be visually and ecologically improved after rehabilitation, and macrophyte establishment was generally considered positive or neutral. [source] Response to cutting of Larrea divaricata and L. cuneifolia in ArgentinaAPPLIED VEGETATION SCIENCE, Issue 1 2002E. Martinez Carretero Abstract. The response of Larrea divaricata and L. cuneifolia to cutting stems 0,20 cm above the ground was studied in the arid piedmont area west of Mendoza, Argentina. The species occur at different elevations and in vegetation zones: L. cuneifolia < 1250 m; L. divaricata between 1250 and 2500 m. Four treatments with 10 replicates were analysed in randomly chosen plants: cut at ground level with lopping shears; cut at ground level with a pick; cut at 10 cm with lopping shears; and cut at 20 cm with lopping shears. The initial and final height, volume, and dry matter (above- and below-ground) were determined. The relation between volume and initial and final dry matter and height was analysed through a factorial MANOVA (p < 0,05), and the functional relation between volume, dry matter and height was estimated by adjusting a regression model. In both species, maximum recovery was reached when cut with shears, and predicted recovery (turnover) was 17-18 yr. In the two last treatments height was a useful predictor of dry matter. L. divaricata -dominated plots have a lower biomass, growth rate, and allocation to stems and root than L. cuneifolia -dominated plots. Regrowth following clipping on an area of 3,10 ha, is sufficient to support the annual needs (cooking and heating) of one family. [source] Effects of the Surrounding Matrix on Tree Recruitment in Amazonian Forest FragmentsCONSERVATION BIOLOGY, Issue 3 2006HENRIQUE E. M. NASCIMENTO efectos de borde; especies pioneras; fragmentación de bosques; bosque lluvioso Abstract:,Little is known about how the surrounding modified matrix affects tree recruitment in fragmented forests. We contrasted effects of two different matrix types, Vismia - and Cecropia -dominated regrowth, on recruitment of pioneer tree species in forest fragments in central Amazonia. Our analyses were based on 22, 1-ha plots in seven experimental forest fragments ranging in size from 1 to 100 ha. By 13 to 17 years after fragmentation, the population density of pioneer trees was significantly higher in plots surrounded by Vismia regrowth than in plots surrounded by Cecropia regrowth, and the species composition and dominance of pioneers differed markedly between the two matrix types. Cecropia sciadophylla was the most abundant pioneer in fragments surrounded by Cecropia regrowth (constituting nearly 50% of all pioneer trees), whereas densities of species in Vismia -surrounded fragments were distributed more evenly. Thus the surrounding matrix had a strong influence on patterns of tree recruitment in Amazonian forest fragments. Resumen:,Se conoce poco del efecto de la matriz modificada circundante sobre el reclutamiento de árboles en bosques fragmentados. Contrastamos los efectos de dos tipos diferentes de matriz, vegetación secundaria dominada por Vismia- y Cecropia-, sobre el reclutamiento de especies de árboles pioneros en fragmentos de bosque en la Amazonía central. Nuestros análisis se basaron en 22 parcelas de 1 ha en siete fragmentos de bosque experimentales que varían entre 1 y 1000 ha. Entre 13 y 17 años después de la fragmentación, la densidad poblacional de árboles pioneros era significativamente mayor en parcelas rodeados por Vismia que en las parcelas rodeadas por Cecropia, y la composición y dominancia de especies pioneras fueron marcadamente diferentes en cada tipo de matriz. Cecropia sciadophylla fue la pionera más abundante en fragmentos rodeados por Cecropia (constituyó casi 50% de todos los árboles pioneros), mientras que las densidades de especies en los fragmentos rodeados por Vismia se distribuyeron más homogéneamente. Por lo tanto, la matriz circundante tiene una fuerte influencia sobre los patrones de reclutamiento de árboles en fragmentos de bosque Amazónicos. [source] TOGp regulates microtubule assembly and density during mitosis and contributes to chromosome directional instabilityCYTOSKELETON, Issue 8 2009Lynne Cassimeris Abstract TOGp, a member of the XMAP215 MAP family, is required for bipolar mitotic spindle assembly. To understand how TOGp contributes to spindle assembly, we examined microtubule dynamics after depleting TOGp by siRNA. Fluorescence recovery after photobleaching of GFP-tubulin demonstrated that spindle microtubule turnover is slowed two-fold in the absence of TOGp. Consistent with photobleaching results, microtubule regrowth after washout of the microtubule depolymerizing drug nocodazole was slower at the centrosomes and in the vicinity of mitotic chromatin in cells depleted of TOGp. The slower microtubule turnover is likely due to either nucleation or the transitions of dynamic instability because TOGp depletion did not effect the rate of plus end growth, measured by tracking EB1-GFP at microtubule ends. In contrast, microtubule regrowth after nocodazole washout was unaffected by prior depletion of TACC3, a centrosomal protein that interacts with TOGp. Kinetochore fibers in both untreated and TOGp-depleted cells were stable to incubation at 4°C or lysis in buffer containing calcium indicating that stable kinetochore-microtubule attachments are formed in the absence of TOGp. Depletion of TOGp, but not TACC3, reduced kinetochore oscillations during prometaphase/metaphase. Defects in oscillations are not due simply to multipolarity or loss of centrosome focus in the TOGp-depleted cells, since kinetochore oscillations appear normal in cells treated with the proteosome inhibitor MG132, which also results in multipolar spindles and centrosome fragmentation. We hypothesize that TOGp is required for chromosome motility as a downstream consequence of reduced microtubule dynamics and/or density. Cell Motil. Cytoskeleton 2009. © 2009 Wiley-Liss, Inc. [source] Silicone Gel Sheeting for the Management and Prevention of OnychocryptosisDERMATOLOGIC SURGERY, Issue 3 2003A. Burhan Aksakal MD BACKGROUND Onychocryptosis, commonly referred to as ingrown nails, has many therapeutic alternatives for its management. Although mild cases can be treated conservatively, in severe cases, surgical treatment is preferred. Silicone gel sheeting is found to be effective in the treatment of hypertrophic scars and keloids. OBJECTIVE To document the effectiveness of silicone gel sheeting in the management of patients with onychocryptosis and in the prevention of the recurrences by breaking the devil's circle, which usually took place after the surgical procedures used in the treatment of the onychocryptosis. METHODS Fourteen patients were enrolled in the study. Entry criteria required the presence of slight (2 patients), moderate (2 patients), or severe (10 patients) onychocryptosis. The simple technique used in the study was the excision of the one-quarter part of the lesional side of the nail plate without excising the granulation tissue. After 24 hours, the silicone was placed on the granulation tissue and the exposed nail bed. Silicone gel sheet was bandaged loosely without applying any pressure. Patients entering the study were given detailed instructions in applying and using the gel for 12 hours during the daytime. The study lasted for 14 months and was composed of a treatment period of 4 months and a follow-up period of 10 months. The patients were evaluated every 2 weeks in the first month and then monthly. The change in thickness of granulation tissue was evaluated by comparing them with the baseline photographs and those taken at each visit. RESULTS The management and prevention of onychocryptosis were achieved in 12 of 14 patients (85.71%). The silicone gel sheeting treatment was well tolerated except for an occasional transient exudation, which was resolved when the treatment was withdrawn. CONCLUSION The results show that the new method that we used for the treatment of onychocryptosis is successful in reducing the thickness of the hypertrophic nail fold and prevents the recurrence of the condition during the regrowth of the nail plate by breaking the devil's circle. The advantage of this method is that it is not destructive to the nail matrix and the adjacent tissue. [source] The Potential Role of Minoxidil in the Hair Transplantation SettingDERMATOLOGIC SURGERY, Issue 10 2002Marc R. Avram background. Over the last decade surgical management of hair loss has become an increasingly popular and satisfying procedure for both men and women, as innovations in donor harvesting, graft size, and hairline design have resulted in consistently natural-appearing hair restoration. objective. In addition, a better understanding of the regulation of the hair-growth cycle has led to advances in the pharmacologic treatment of androgenetic alopecia. methods. Currently there are two U.S. Food and Drug Administration (FDA)-approved agents that promote hair regrowth: over-the-counter topical minoxidil solution for men and women and prescription oral finasteride tablets for men. In October 2001, a group of 11 international experts on hair loss and hair transplantation convened to review the physiology and effects of pharmacologic treatments of hair loss and to discuss the value of administering topical minoxidil therapy as an adjunct to hair transplantation. results. This article presents the key findings and consensus points among the participants, including their current use of pharmacologic treatments, strategies for optimal results both pre- and postsurgery, and the importance of realistic patient expectations and compliance. conclusions. Based on the surgeons' clinical experience, the use of approved hair regrowth agents in hair transplant patients with viable but suboptimally functioning follicles in the region to be transplanted can increase hair density, speed regrowth in transplanted follicles, and complement the surgical result by slowing down or stopping further hair loss. [source] Treatment of Recurrent Ingrown Great Toenail Associated with Granulation Tissue by Partial Nail Avulsion Followed by Matricectomy with Sharpulse Carbon Dioxide LaserDERMATOLOGIC SURGERY, Issue 5 2002Kuo-chia Yang MD background. The effectiveness of partial nail avulsion followed by matricectomy with carbon dioxide (CO2) laser for the treatment of ingrown great toenails remains unclear. objective. This study sought to determine the effectiveness of partial nail avulsion followed by matricectomy with sharpulse CO2 laser in the treatment of recurrent ingrown great toenails associated with granulation tissue. materials and methods. Fourteen patients with a total of 18 recurrent ingrown great toenails were randomly selected for participation in this study. Partial nail avulsions followed by matricectomy with sharpulse CO2 laser were performed on the involved nails. After at least 6 months, we evaluated the recurrence of ingrown toenails, regrowth of the nail spike, duration of post-treatment pain and post-treatment infection. results. Partial nail avulsion followed by matricectomy with sharpulse CO2 laser in the treatment of ingrown toenails resulted in a high cure rate, short postoperative pain duration and low risk of postoperative infection. conclusion. This method we advocate is convenient and effective for the treatment of recurrent ingrown great toenail associated with granulation tissue. [source] Comparison of Long-Pulsed Diode and Long-Pulsed Alexandrite Lasers for Hair Removal: A Long-Term Clinical and Histologic StudyDERMATOLOGIC SURGERY, Issue 7 2001Christiane Handrick MD Background. Unwanted facial and body hair is a common problem, generating a high level of interest for treatment innovations. Advances in laser technology over the past several years has led to the development and distribution of numerous red and infrared lasers and light sources to address this issue. Despite the impressive clinical results that have been reported with the use of individual laser hair removal systems, long-term comparative studies have been scarce. Objective. To compare the clinical and histologic efficacy, side effect profile, and long-term hair reduction of long-pulsed diode and long-pulsed alexandrite laser systems. Methods. Twenty women with Fitzpatrick skin types I,IV and dark terminal hair underwent three monthly laser-assisted hair removal sessions with a long-pulsed alexandrite laser (755 nm, 2-msec pulse, 10 mm spot) and a long-pulsed diode laser (800 nm, 12.5 msec or 25 msec, 9 mm spot). Axillary areas were randomly assigned to receive treatment using each laser system at either 25 J/cm2 or 40 J/cm2. Follow-up manual hair counts and photographs of each area were obtained at each of the three treatment visits and at 1, 3, and 6 months after the final laser session. Histologic specimens were obtained at baseline, immediately after the initial laser treatment, and 1 and 6 months after the third treatment session. Results. After each laser treatment, hair counts were successively reduced and few patients found it necessary to shave the sparsely regrown hair. Optimal clinical response was achieved 1 month after the second laser treatment, regardless of the laser system or fluence used. Six months after the third and final treatment, prolonged clinical hair reduction was observed with no significant differences between the laser systems and fluences used. Histologic tissue changes supported the clinical responses observed with evidence of initial follicular injury followed by slow follicular regeneration. Side effects, including treatment pain and vesiculation, were rare after treatment with either laser system, but were observed more frequently with the long-pulsed diode system at the higher fluence of 40 J/cm2. Conclusion. Equivalent clinical and histologic responses were observed using a long-pulsed alexandrite and a long-pulsed diode laser for hair removal with minimal adverse sequelae. While long-term hair reduction can be obtained in most patients after a series of laser treatments, partial hair regrowth is typical within 6 months, suggesting the need for additional treatments to improve the rate of permanent hair removal. [source] Hair Removal Using a Long-Pulsed Nd:YAG Laser: Comparison at Fluences of 50, 80, and 100 J/cm2DERMATOLOGIC SURGERY, Issue 5 2001David J. Goldberg MD Background. Unwanted hair is a widespread cosmetic problem. Many temporary methods of hair removal have proved unsatisfactory. A variety of laser systems with varying wavelengths, pulse durations, and energy fluences are currently utilized for hair removal. Optimal laser parameters continue to require further investigation. Objective. To evaluate the efficacy and safety of a long-pulse millisecond Nd:YAG hair removal laser utilizing fluences of either 50, 80, or 100 J/cm2. Methods. Fifteen subjects were treated with a contact cooled 50 msec Nd:YAG laser at fluences 30, 50, or 100 J/cm2. Reduction in hair regrowth was measured at 3 months after treatment by comparing the terminal hair count to the baseline values. Potential complications were also evaluated. Results. Average hair reduction at 3 months after treatment was 29%, 29%, and 27% in areas treated with a 50-msec Nd:YAG laser at fluences of 50, 80, and 100 J/cm2, respectively. Although short-term blistering was noted in two subjects, no hyperpimentation, hypopigmentation, or scarring was observed at 3 months after treatment. Conclusion. Long-pulse millisecond Nd:YAG laser hair removal with fluences of either 50, 80, or 100 J/cm2 leads to similar efficacy with no significant adverse effects. [source] Clinical presentations of alopecia areataDERMATOLOGIC THERAPY, Issue 4 2001Maria K. Hordinsky Alopecia areata (AA) may can occur on any hair-bearing region. Patients can develop patchy nonscarring hair loss or extensive loss of all body hair. Hair loss may fluctuate. Some patients experience recurrent hair loss followed by hair regrowth, whereas others may only develop a single patch of hair loss, never to see the disease again. Still others experience extensive loss of body hair. The heterogeneity of clinical presentations has led investigators conducting clinical therapeutic trials to typically group patients into three major groups, those with extensive scalp hair loss [alopecia totalis (AT)], extensive body hair loss [alopecia universalis (AU)], or patchy disease (AA). Treatment outcomes have been correlated with disease duration and extent. Recently, guidelines were established for selecting and assessing subjects for both clinical and laboratory studies of AA, thereby facilitating collaboration, comparison of data, and the sharing of patient-derived tissue. For reporting purposes the terms AT and AU, though still used are defined very narrowly. AT is 100% terminal scalp hair loss without any body hair loss and AU is 100% terminal scalp hair and body loss. AT/AU is the term now recommended to define the presence of AT with variable amounts of body hair loss. In this report the term AA will be used broadly to encompass the many presentations of this disease. Development of AA may occur with changes in other ectodermal-derived structures such as fingernails and toenails. Some investigators have also suggested that other ectodermal-derived appendages as sebaceous glands and sweat glands may be affected in patients experiencing AA. Whether or not function of these glands is truly impaired remains to be confirmed. Many patients who develop patchy or extensive AA complain of changes in cutaneous sensation, that is, burning, itching, tingling, with the development of their disease. Similar symptoms may occur with hair regrowth. The potential involvement of the nervous system in AA has led to morphologic investigations of the peripheral nervous system as well as analysis of circulating neuropeptide levels. In this article the clinical presentations of AA are reviewed. The guidelines for conducting treatment studies of AA are presented and observations on changes in cutaneous innervation are introduced. Throughout the text, unless otherwise noted, AA will be used in a general way to denote the spectrum of this disease. [source] The histopathology of alopecia areata in vertical and horizontal sectionsDERMATOLOGIC THERAPY, Issue 4 2001David A. Whiting Alopecia areata (AA) is a relatively common disease affecting 1.7% of Americans by the age of 50 years. The diagnosis is usually made on clinical grounds. In some cases the diagnosis is elusive and biopsies are necessary. In other cases biopsies are useful from a prognostic point of view to determine whether there are enough follicles left for possible future regrowth. In view of the active research being conducted into AA, biopsies provide valuable material for further investigation. The diagnosis of AA is improved by the use of horizontal sections in addition to or instead of vertical sections of scalp biopsies. The histopathologic features favoring the diagnosis of AA include peribulbar and intrabulbar mononuclear infiltrates, degenerative changes in the hair matrix, decreased numbers of terminal anagen follicles, increased numbers of terminal catagen and telogen follicles, an increased number of follicular stelae, an increased number of miniaturized vellus hair follicles, and pigment incontinence of hair bulbs and follicular stelae. Follicular counts with horizontal sections are particularly helpful in making the diagnosis of AA when the biopsy has been taken between acute episodes and the characteristic peribulbar inflammatory infiltrate is absent. [source] Accelerated neuritogenesis and maturation of primary spinal motor neurons in response to nanofibersDEVELOPMENTAL NEUROBIOLOGY, Issue 8 2010Caitlyn C. Gertz Abstract Neuritogenesis, neuronal polarity formation, and maturation of axons and dendrites are strongly influenced by both biochemical and topographical extracellular components. The aim of this study was to elucidate the effects of polylactic acid electrospun fiber topography on primary motor neuron development, because regeneration of motor axons is extremely limited in the central nervous system and could potentially benefit from the implementation of a synthetic scaffold to encourage regrowth. In this analysis, we found that both aligned and randomly oriented submicron fibers significantly accelerated the processes of neuritogenesis and polarity formation of individual cultured motor neurons compared to flat polymer films and glass controls, likely due to restricted lamellipodia formation observed on fibers. In contrast, dendritic maturation and soma spreading were inhibited on fiber substrates after 2 days in vitro. This study is the first to examine the effects of electrospun fiber topography on motor neuron neuritogenesis and polarity formation. Aligned nanofibers were shown to affect the directionality and timing of motor neuron development, providing further evidence for the effective use of electrospun scaffolds in neural regeneration applications. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 70: 589,603, 2010 [source] 5-Aminolaevulinic acid-induced photodynamic therapy and photodetection in Barrett's esophagusDISEASES OF THE ESOPHAGUS, Issue 3 2004P. E. Claydon SUMMARY., Barrett's esophagus is a precursor of adenocarcinoma of the esophagus. This cancer has the fastest growing incidence of any solid tumor in the Western world. Surveillance of Barrett's esophagus is routinely undertaken to detect early malignant transformation. However, ablative endoscopic treatments are available and these can obliterate the abnormal epithelium, allowing neosquamous regrowth. Photodynamic therapy using 5-aminolaevulinic acid (ALA) is such a technique. In this non-thermal method of ablation, ALA is metabolized to produce the photosensitizer protoprophyrin IX. This, together with light and oxygen, produces local tissue destruction. Fluorescence detection using ALA has also been used to identify areas of dysplasia and thus enhance positive biopsy yield. The use of ALA in photodynamic therapy and photodetection is reviewed. [source] Host plant variation in plant-mediated indirect effects: moth boring-induced susceptibility of willows to a specialist leaf beetleECOLOGICAL ENTOMOLOGY, Issue 2 2008SHUNSUKE UTSUMI Abstract 1.,We examined the plant-mediated indirect effects of the stem-boring moth Endoclita excrescens (Lepidoptera: Hepialidae) on the leaf beetle Plagiodera versicolora (Coleoptera: Chrysomelidae) in three willow species, Salix gilgiana, S. eriocarpa, and S. serissaefolia. 2.,When the stem-boring moth larvae damaged stems in the previous year, willows were stimulated to produce vigorously growing lateral shoots on these stems. These new lateral shoots were significantly longer and the upper leaves had significantly higher nitrogen and water content than current-year shoots on unbored stems, although the carbon content and leaf dry mass were not different between lateral and current-year shoots. 3.,In the field, leaf beetle larvae and adults had significantly greater densities on lateral shoots of bored stems than on current-year shoots of unbored stems. A laboratory experiment showed that female beetles had significantly greater mass and fecundity when fed on leaves of newly-emerged lateral shoots. Thus, the stem-boring moth had a positive effect on the temporally and spatially separated leaf beetle by increasing resource availability by inducing compensatory regrowth. 4.,The strength of the indirect effects on the density and performance of the leaf beetle differed among willow species, because there was interspecific variation in host quality and herbivore-induced changes in plant traits. In particular, we suggest that the differences in magnitude of the changes among willow species in shoot length and leaf nitrogen content greatly affected the strength of the plant-regrowth mediated indirect effect, coupled with host-plant preference of the leaf beetle. [source] Restoration of forest structure in managed regrowth at Rocky Creek Dam, AustraliaECOLOGICAL MANAGEMENT & RESTORATION, Issue 2 2008Jennifer C. Sanger No abstract is available for this article. [source] Restoration potential of Brigalow regrowth: Insights from a cross-sectional study in southern QueenslandECOLOGICAL MANAGEMENT & RESTORATION, Issue 3 2007Timothy S. Chandler First page of article [source] The effect of concentrated smoke products on the restoration of highly disturbed mineral sands in southeast VictoriaECOLOGICAL MANAGEMENT & RESTORATION, Issue 2 2003By Terry D. Coates Summary Recent studies have recognized the potential of broad-scale surface application of smoke compounds for enhancing germination from the soil seed-bank in fire-prone vegetation communities. Results suggest that smoke technology may play, in the future, a significant role in the restoration and management of areas supporting indigenous vegetation. An important step in the development of smoke-based restoration tools is the conduct of in situ field trials in a range of geographical locations and environmental conditions. However, most of the published work on the effectiveness of smoke products in promoting seedbank germination has been conducted at sites in southwestern Australia. The present study examines the effect of commercially available smoke-water products on the regeneration of a highly disturbed former mine-site at the Royal Botanic Gardens Cranbourne, in southeastern Victoria. Various combinations of concentrated smoke products and topsoil harvested from a nearby heathy woodland community were applied to exposed, uniform mineral sands to test their effect on seedling density and species richness of regrowth. The trials showed that after 12 months a number of common, herbaceous species including Austrodanthonia setacea, Opercularia varia and Platysace heterophylla were recorded in significantly higher numbers in areas treated with a commercial smoke-water. However, there was no overall improvement in the density of seedlings or the richness of species as a result of the application of the smoke products. Similarly, total seedling density and species richness were not affected by the addition of topsoil, either alone or in combination with smoke products. [source] Comparative seed ecology of the endangered shrub, Pimelea spicata and a threatening weed, Bridal Creeper: Smoke, heat and other fire-related germination cuesECOLOGICAL MANAGEMENT & RESTORATION, Issue 1 2003Anthony J. Willis SummaryPimelea spicata R. Br. is a nationally listed endangered Australian shrub threatened with extinction by habitat fragmentation and environmental weed invasion. Bridal Creeper (Asparagus asparagoides L. W. Wight) is the primary weed threat to the largest remaining populations of P. spicata in the Cumberland Plain. Fire, as part of an integrated pest management program, offers the potential to stimulate P. spicata populations while controlling Bridal Creeper. It is important, therefore, to understand how the components of fire affect the germination and growth of both species. Using laboratory experiments we investigated the effects of smoke, heat, ash and/or light on the germination of P. spicata and Bridal Creeper. We found a significant promotive effect of smoke and indication of an inhibitory heat shock (90°C for 10 min) effect on the germination of P. spicata seeds. The response of Bridal Creeper seeds to the same factors was complex; while the results of one experiment suggested an inhibitory effect of smoke and a promotive effect of heat, subsequent trials were contradictory, implying that Bridal Creeper, like many weeds, is able to germinate under a wide range of environmental conditions. Other experiments investigated the optimal germination temperature and innate dormancy of P. spicata in the absence of fire-related germination cues. Of the incubation temperatures investigated, the optimal diurnally fluctuating regime for P. spicata germinations was 10°C and 20°C in the night and day, respectively. The innate dormancy of freshly produced seeds disappeared after 3 months. In contrast to Bridal Creeper, we found a persistent germinable seed bank of about 97 P. spicata seeds/m2 located in the top 5 cm of the soil profile. While fire alone is unlikely to kill Bridal Creeper plants, fire may help to manage local infestations of the weed by limiting germination and providing opportunity for herbicide treatment of regrowth. [source] The effects of polychlorinated biphenyls (Aroclor 1242) on thyroxine, estradiol, molt, and plumage characteristics in the American kestrel (Falco sparverius)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2002Michael J. Quinn Jr. Abstract The purpose of this experiment was to determine the effects of Aroclor 1242, a mixture of polychlorinated biphenyls (PCBs), on plumage characteristics and molt in the American kestrel, Falco sparverius. Several characteristics of plumage, including color and molt schedule, are modulated by hormonal signals and hence may be modified by endocrine-active contaminants. If so, the functions of plumage (e.g., communication for mating or territorial defense) may be compromised by exposure to such compounds. Captive American kestrels were fed Aroclor 1242 at 0, 6.0, and 60.0 ppm (n = 6 males and 6 females per treatment) mixed in their normal diet. Concentrations of plasma estradiol and thyroxine were measured weekly from the beginning of treatment. Measured plumage characteristics included width of the black subterminal band on the tail, color (a composite index of hue and saturation), reflectance from 230 to 800 nm, pattern of feather loss and regrowth on the tail and wing, and timing of onset and duration of molt. Aroclor 1242 depressed plasma thyroxine. Plasma estradiol levels remained low due to the phase of the breeding cycle. Treatments did not disrupt the measured plumage characteristics. This may be due to timing or dose of exposure or to genetic factors. [source] Treatment of an osteoblastic osteosarcoma in an aged geldingEQUINE VETERINARY EDUCATION, Issue 4 2010T. Springer Summary A 27-year-old Thoroughbred gelding was examined for a right nasal mass visible inside the right nares. Airflow through the right nostril was absent. Endoscopy and radiography revealed the mass to occupy the entire right nasal passage. Nasal biopsies were inconclusive, so en bloc resection was performed. A diagnosis of an incompletely resected osteoblastic osteosarcoma was made. Endoscopic biopsies performed 4 weeks post surgery revealed osteosarcoma cells present in the caudal right nasal cavity. Metastatic disease was not present in mandibular lymph node aspirates or on thoracic radiographs. The right nasal passage was irradiated with 12 treatments over the course of 4 weeks. Comfort and quality of life were excellent during treatment and no adverse side effects were noted. Endoscopy and follow-up biopsies at 1, 2, 4, 12 and 14 months post radiation therapy have not found any evidence of regrowth of the osteosarcoma. [source] Fatty acid ruminal metabolism and digestibility in cows fed perennial ryegrassEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 8 2007Michel Doreau Abstract The ruminal metabolism and intestinal digestibility of fatty acids (FA) was studied in four mid-lactation dairy cows fitted with ruminal and duodenal cannulae. The cows received fresh perennial ryegrass as sole feed. Two grasses were compared, differing in the soluble carbohydrate/nitrogen ratio (SC+/N, and SC,/N+ ratios). This ratio was modified by the combination of three factors: age of regrowth, N,fertilisation and hour of cutting. The two grasses contained 12.5 and 20.7% of crude protein, and 24.6 and 13.7% of SC, respectively. The SC+/N, grass contained less FA [1.82 vs. 2.49% of dry matter (DM)] and a lower percentage of linolenic acid (60.9 vs. 65.6% of FA). As DM intake did not differ between treatments, FA intake was higher for the SC,/N+ treatment. The duodenal composition of FA revealed numerous isomers of 18:1 and conjugated and non-conjugated isomers of 18:2. SC,/N+ treatment resulted in a higher duodenal flow of stearic, linoleic, and linolenic acids and of several intermediates of linolenic acid hydrogenation. This was a consequence of differences in intake. Intestinal digestibility of FA from both grasses was high (around 90%). The proportions of FA in plasma did not reflect with accuracy the differences in duodenal FA resulting from differences in ruminal metabolism. [source] Adult neural progenitor cells provide a permissive guiding substrate for corticospinal axon growth following spinal cord injuryEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2004Katharina Pfeifer Abstract Adult neural progenitor cells (NPC) are an attractive source for cell transplantation and neural tissue replacement after central nervous system (CNS) injury. Following transplantation of NPC cell suspensions into the acutely injured rat spinal cord, NPC survive; however, they migrate away from the lesion site and are unable to replace the injury-induced lesion cavity. In the present study we examined (i) whether NPC can be retained within the lesion site after co-transplantation with primary fibroblasts, and (ii) whether NPC promote axonal regeneration following spinal cord injury. Co-cultivation of NPC with fibroblasts demonstrated that NPC adhere to fibroblasts and the extracellular matrix produced by fibroblasts. In the presence of fibroblasts, the differentiation pattern of co-cultivated NPC was shifted towards glial differentiation. Three weeks after transplantation of adult spinal-cord-derived NPC with primary fibroblasts as mixed cell suspensions into the acutely injured cervical spinal cord in adult rats, the lesion cavity was completely replaced. NPC survived throughout the graft and differentiated exclusively into glial cells. Quantification of neurofilament-labeled axons and anterogradely labeled corticospinal axons indicated that NPC co-grafted with fibroblasts significantly enhanced axonal regeneration. Both neurofilament-labeled axons and corticospinal axons aligned longitudinally along GFAP-expressing NPC-derived cells, which displayed a bipolar morphology reminiscent of immature astroglia. Thus, grafted astroglial differentiated NPC promote axon regrowth following spinal cord injury by means of cellular guidance. [source] Serum levels of IL-18 and sIL-2R in patients with alopecia areata receiving combined therapy with oral cyclosporine and steroidsEXPERIMENTAL DERMATOLOGY, Issue 2 2010Deborah Lee Please cite this paper as: Serum levels of IL-18 and sIL-2R in patients with alopecia areata receiving combined therapy with oral cyclosporine and steroids. Experimental Dermatology 2010; 19: 145,147. Abstract:, This study was to determine which immunologic factors contribute to the prognosis of patients with alopecia areata (AA) who were receiving oral cyclosporine A and methylprednisolone. Patients with >25% hair regrowth were defined as responders, and patients exhibiting ,25% regrowth were poor-responders. The serum levels of IL-18 and soluble IL-2 receptor (sIL-2R) were measured at baseline in 21 patients with AA and 22 control subjects. The mean serum level of IL-18 in the patients with extensive AA was significantly higher than that in the control subjects. The mean serum concentration of sIL-2R in the AA patients significantly decreased after 1 month of treatment. The mean basal serum level of IL-18 was highest in the responder, whereas the baseline level of sIL-2R was significantly higher in the poor-responder group than other groups. In conclusion, increased serum sIL-2R level and lower IL-18 level at baseline was associated with a poor prognosis in patients with AA. [source] Influence of prostaglandin F2, and its analogues on hair regrowth and follicular melanogenesis in a murine modelEXPERIMENTAL DERMATOLOGY, Issue 5 2005S. Sasaki Abstract:, Latanoprost and isopropyl unoprostone, which are analogues of prostaglandin F2, (PGF2,), are promising drugs for the reduction of intra-ocular pressure. However, they have been reported to have side effects, including hypertrichosis and hyperpigmentation of the eyelashes and periocular skin, and occasionally poliosis. In order to investigate these effects further, PGF2,, latanoprost and isopropyl unoprostone were applied to the dorsal skin of 7-week-old C57BL/6 mice, and hair length was measured during the treatment. The three molecules all showed stimulatory effects on the murine hair follicles and the follicular melanocytes in both the telogen and anagen stages, and stimulated conversion from the telogen to the anagen phase. PGE2 is known to act synergistically with PGF2,, and hence the influence of PGE2 was also examined. PGE2 did not induce distinct telogen-to-anagen conversion, but showed moderate growth stimulatory effects on early anagen hair follicles. In addition, we observed a case of hypertrichosis and trichomegaly with an excess of melanogenesis, leading to the emergence of white hair, suggesting that poliosis can occur as a side effect of eye treatment with solutions of PGF2, analogues. The stimulatory effects of PGF2,and PGE2 on hair growth have been discussed with regard to the role of protein kinase C and mast cells. [source] Monitoring bacterial and archaeal community shifts in a mesophilic anaerobic batch reactor treating a high-strength organic wastewaterFEMS MICROBIOLOGY ECOLOGY, Issue 3 2008Changsoo Lee Abstract Shifts in bacterial and archaeal communities, associated with changes in chemical profiles, were investigated in an anaerobic batch reactor treating dairy-processing wastewater prepared with whey permeate powder. The dynamics of bacterial and archaeal populations were monitored by quantitative real-time PCR and showed good agreement with the process data. A rapid increase in bacterial populations and a high rate of substrate fermentation were observed during the initial period. Growth and regrowth of archaeal populations occurred with biphasic production of methane, corresponding to the diauxic consumption of acetate and propionate. Bacterial community structure was examined by denaturing gel gradient electrophoresis (DGGE) targeting 16S rRNA genes. An Aeromonas -like organism was suggested to be mainly responsible for the rapid fermentation of carbohydrate during the initial period. Several band sequences closely related to the Clostridium species, capable of carbohydrate fermentation, lactate or ethanol fermentation, and/or homoacetogenesis, were also detected. Statistical analyses of the DGGE profiles showed that the bacterial community structure, as well as the process performance, varied with the incubation time. Our results demonstrated that the bacterial community shifted, reflecting the performance changes and, particularly, that a significant community shift corresponded to a considerable process event. This suggested that the diagnosis of an anaerobic digestion process could be possible by monitoring bacterial community shifts. [source] Inability of Escherichia coli to resuscitate from the viable but nonculturable stateFEMS MICROBIOLOGY ECOLOGY, Issue 1 2007Inés Arana Abstract After induction of the viable but nonculturable (VBNC) state in Escherichia coli populations, we analysed abiotic and biotic factors suggested to promote the resuscitation process. The response to the stressing conditions implied the formation of three subpopulations, culturable, VBNC and nonviable. In most adverse situations studied, the VBNC subpopulation did not represent the dominant fraction, decreasing with time. This suggests that, in most cases, the VBNC is not a successful phenotype. Combining methods of dilution and inhibition of remaining culturable cells, we designed a working protocol in order to distinguish unequivocally between regrowth and resuscitation. Reversion of abiotic factors inducing nonculturability as well as prevention of additional oxidative stress did not provoke resuscitation. Participation of biotic factors was studied by addition of supernatants from different origin without positive results. These results indicate that the E. coli strain used is not able to resuscitate from the VBNC state. VBNC cells release into the surrounding medium, and could thus aid in the survival of persisting culturable cells. The formation of a VBNC subpopulation could thus be considered as an adaptive process, designed for the benefit of the population as a whole. [source] Structural biomass partitioning in regrowth and undisturbed mesquite (Prosopis glandulosa): implications for bioenergy usesGCB BIOENERGY, Issue 1 2010R. JAMES ANSLEY Abstract Honey mesquite (Prosopis glandulosa Torr.) which grows on grasslands and rangelands in southwestern USA may have potential as a bioenergy feedstock because of existing standing biomass and regrowth potential. However, regrowth mesquite physiognomy is highly different from undisturbed mesquite physiognomy and little is known regarding growth rates and structural biomass allocation in regrowth mesquite. We compared canopy architecture, aboveground biomass and relative allocation of biomass components in regrowth (RG) trees of different known ages with undisturbed (UD) trees of similar canopy height to each RG age class. RG trees in most age classes (2,12 years old) had greater canopy area, leaf area, basal stem number, twig (<0.5 cm diameter) mass and small stem (0.5,3 cm diameter) mass than UD trees of the same height. Large stem (>3 cm diameter) mass was similar between RG and UD trees in all height classes. Ages of UD trees were determined after harvest and further comparisons were made between age, canopy structure and biomass in RG and UD trees. Relationships between age and total mass, age and height, and age and canopy area indicated a faster growth rate in RG than in UD trees. Large stem mass as a percentage of total tree mass accumulated more rapidly with age in RG than UD trees. Leaf area index and leaf : twig mass ratio were maintained near 1 in all RG and UD trees. Regrowth potential may be one of the most important features of mesquite in consideration as a bioenergy feedstock. [source] | ||||||||||||||||||||||||||||||||||||||||||||||