Patchy Treatments Research Articles

Superficial Cryotherapy versus Intralesional Corticosteroids Injection in Alopecia Areata

Background:Alopecia areata (AA) is an autoimmune disease leading to noncicatricial alopecia. Topical or intralesional corticosteroid (ILCS) is the accepted therapeutic option for mild cases; however, adverse effects are sometimes difficult to reverse. When the exposure to liquefied nitrogen is limited to a few seconds “superficial” cryotherapy, reactive vasodilation may improve microcirculation and nutritional status around hair follicles.Objective:This study aimed to evaluate and compare superficial cryotherapy and ILCS in the treatment of patchy AA.Materials and Methods:This prospective comparative study included 21 patients with patchy AA. Every patient received superficial cryotherapy on one patch, every 2 weeks for 3 months, and ILCS injection for another patch, once monthly for 3 months.Results:Clinical improvement was higher in cryotherapy group compared to ILCS group with a statistically significant difference (P = 0.002). On trichoscopic evaluation, terminal hair count was improved in lesions treated with cryotherapy more than lesions treated with ILCS but without statistical significance (P = 0.595) and vellus hair count was improved in lesions treated with cryotherapy more than lesions treated with ILCS with a statistical significance (P = 0.002).Conclusions:Cryotherapy is more effective and less painful than ILCS in the treatment of patchy AA.

A Retrospective Comparative Study of Two Concentrations of Intralesional Triamcinolone Acetonide in the Treatment of Patchy Alopecia Areata on the Scalp.

BackgroundAlopecia areata (AA) usually manifests as patches of non-scarring hair loss due to immune dysregulation. Intradermal injection of steroids is considered a first-line treatment of patchy AA.PurposeTo compare the efficacy and safety of two commonly used concentrations of intralesional triamcinolone acetonide (ILT) (5 mg/mL vs 10 mg/mL) in the treatment of patchy AA on the scalp.Patients and MethodsA retrospective comparative study that included 85 patients diagnosed with patchy AA on the scalp, who were treated with monthly injections of ILT. Patients were divided into Group 1 that received 5 mg/mL and Group 2 that received 10 mg/mL. The response rate (defined as the percentage of patients who achieved complete hair regrowth) and the side effects were compared between the two groups after completion of three treatment sessions, and recurrence was assessed after 1−3 years.ResultsDemographic composition of the two groups was comparable. The difference in response rate and the side-effects between the two groups were not statistically significant. Complete hair regrowth was noted in 43.5% of patients in Group 1 and 53.8% of those in Group 2 (P=0.340). About 17% and 25% of patients in Group 1 and Group 2, respectively, developed minor local side-effects (P=0.354), and almost 45% of patients from both groups had recurrence after 1−3 years. Disease duration exceeding 6 months correlated with poor treatment response.ConclusionIntralesional injection of triamcinolone acetonide 5 mg/mL is equally effective and safe compared to 10 mg/mL in the treatment of patchy alopecia areata.

Targeted photochemotherapy in alopecia areata

Alopecia areata (AA) is a common cause of localized non-scarring alopecia. Usage of targeted UVA after the topical application of 8-methoxypsoralen (8-MOP) is one of the rising treatment modalities for AA. Our aim was to assess the efficacy and safety of topical 8-MOP plus targeted UVA phototherapy in the treatment of patchy AA. Seven patchy AA patients were treated by topical 8-MOP application to the lesions followed by UVA irradiation 3 times a week, with 15 to 24 sessions in total. At the end of the treatment all patients were evaluated for response on a four-point scale (0 = no hair, 1 = white vellus hair, 2 = regrowth cosmetically acceptable for the patient, 3 = complete hair growth). The mean cumulative UVA dose was from 7.5 to 39.6 J/cm(2) . For all 7 patients, average response score was calculated as 2, which means cosmetically acceptable regrowth. Targeted UVA phototherapy combined with topical 8-MOP may be an effective and safe alternative treatment protocol for patchy AA, which should be kept in mind in order to choose the best for the patient, especially for patients incompatible with other treatments that are systemic and invasive.

Soil Particle Heterogeneity Affects the Growth of a Rhizomatous Wetland Plant

Soil is commonly composed of particles of different sizes, and soil particle size may greatly affect the growth of plants because it affects soil physical and chemical properties. However, no study has tested the effects of soil particle heterogeneity on the growth of clonal plants. We conducted a greenhouse experiment in which individual ramets of the wetland plant Bolboschoenus planiculmis were grown in three homogeneous soil treatments with uniformly sized quartz particles (small: 0.75 mm, medium: 1.5 mm, or large: 3 mm), one homogeneous treatment with an even mixture of large and medium particles, and two heterogeneous treatments consisting of 16 or 4 patches of large and medium particles. Biomass, ramet number, rhizome length and spacer length were significantly greater in the treatment with only medium particles than in the one with only large particles. Biomass, ramet number, rhizome length and tuber number in the patchy treatments were greater in patches of medium than of large particles; this difference was more pronounced when patches were small than when they were large. Soil particle size and soil particle heterogeneity can greatly affect the growth of clonal plants. Thus, studies to test the effects of soil heterogeneity on clonal plants should distinguish the effects of nutrient heterogeneity from those of particle heterogeneity.

Effects of light heterogeneity on growth of a submerged clonal macrophyte

AbstractMany studies have examined the effects of spatial heterogeneity in light supply on clonal plants in terrestrial environments, but few have examined those in aquatic conditions. In a greenhouse experiment, we grew the rhizomatous submerged macrophyte Vallisneria spiralis L. in containers in three homogeneous light treatments (100%, 65%, and 30% of ambient light coded as high, medium, and low light, respectively) and two heterogeneous ones differing in patch scale (small and large patch). The growth of V. spiralis decreased significantly with decreasing light availability. In the low light conditions, V. spiralis allocated greater biomass to shoots and developed elongated leaves. In the patchy treatments, ramets distributed in the light‐rich patches had significant costs in the large patch treatment, but not in the small patch treatment, while both small and large patch treatments had no significant benefits in the light‐poor patches. We conclude that V. spiralis could escape from adverse habitats and occupy the favorable habitats. Providing the same amount of light, responses of V. spiralis to different patch scales were different at the patch level, but not at the whole clone level. Together, growth of V. spiralis could not benefit from different patch scales in heterogeneous environments at the patch as well as the whole clone level.

Patchy distributions of Spirogyra arcta do not affect growth of the submerged macrophyte Ceratophyllum demersum

AbstractSpatial heterogeneity is common in aquatic conditions, but few studies have examined the effects of heterogeneous distributions of biological factors on aquatic plants. Spirogyra (Spirogyra arcta) coexists with many submerged macrophytes, such as Ceratophyllum demersum, but no study has examined the effects of heterogeneous distributions of spirogyra on the growth of submerged plants. We grew the submerged plant C. demersum in three homogeneous, aquatic conditions (0, 50 and 100% of the water surface in the container was evenly covered by spirogyra, referred to as ‘control’, ‘50%’ and ‘100%’, respectively) and two patchy conditions (the left half of the water surface in the container was not covered by spirogyra and 50% and 100% of the water surface in the right half of the container was evenly covered by spirogyra, referred to as ‘50%‐patchy’ and ‘100%‐patchy’, respectively). Compared with the control, the 100% treatment greatly decreased the biomass and number of ramets of C. demersum, but the 50% treatment did not. Growth of C. demersum in the left half of the container did not differ significantly between the control and the two heterogeneous treatments (50%‐patchy and 100%‐patchy). In addition, growth of C. demersum in the right half of the container did not differ between the 100% and the 100%‐patchy treatment or between the 50% and the 50%‐patchy treatment. Our results suggest that C. demersum can tolerate shading by spirogyra to a certain extent and that heterogeneous distributions of spirogyra do not affect its growth.

Effect of configuration on spectral signatures

A 4-month controlled laboratory experiment was conducted to determine the impact of spatial configurational change on spectral characteristics of grasses. Eight different planting configurations were examined of two grass seed mixtures (sun and shade grass and Kentucky bluegrass) of equal composition (50% each). Spectral properties were quantified using (i) leaf area index (LAI), (ii) normalized difference vegetation index (NDVI) and soil-adjusted vegetation index (SAVI), and (iii) an unsupervised iterative self-organizing data analysis (ISODATA) classification. Analysis of variance (ANOVA) tests were performed for LAI, NDVI, and SAVI; Tukey’s post-hoc tests showed significant differences between random and all other treatments for LAI means, no significant differences for NDVI means, and significant differences between irregularly patchy and regularly patchy treatments for SAVI means. Chi-square tests on the four-class aggregation results for ISODATA indicated that configuration does influence the spectral characteristics that drive image classification. This study reflects upon the importance of configuration in spatial pattern analysis for remote sensing of similar surface features with internally heterogeneous properties.

Fish Responses to Experimental Fragmentation of Seagrass Habitat

Understanding the consequences of habitat fragmentation has come mostly from comparisons of patchy and continuous habitats. Because fragmentation is a process, it is most accurately studied by actively fragmenting large patches into multiple smaller patches. We fragmented artificial seagrass habitats and evaluated the impacts of fragmentation on fish abundance and species richness over time (1 day, 1 week, 1 month). Fish assemblages were compared among 4 treatments: control (single, continuous 9-m(2) patches); fragmented (single, continuous 9-m(2) patches fragmented to 4 discrete 1-m(2) patches); prefragmented/patchy (4 discrete 1-m(2) patches with the same arrangement as fragmented); and disturbance control (fragmented then immediately restored to continuous 9-m(2) patches). Patchy seagrass had lower species richness than actively fragmented seagrass (up to 39% fewer species after 1 week), but species richness in fragmented treatments was similar to controls. Total fish abundance did not vary among treatments and therefore was unaffected by fragmentation, patchiness, or disturbance caused during fragmentation. Patterns in species richness and abundance were consistent 1 day, 1 week, and 1 month after fragmentation. The expected decrease in fish abundance from reduced total seagrass area in fragmented and patchy seagrass appeared to be offset by greater fish density per unit area of seagrass. If fish prefer to live at edges, then the effects of seagrass habitat loss on fish abundance may have been offset by the increase (25%) in seagrass perimeter in fragmented and patchy treatments. Possibly there is some threshold of seagrass patch connectivity below which fish abundances cannot be maintained. The immediate responses of fish to experimental habitat fragmentation provided insights beyond those possible from comparisons of continuous and historically patchy habitat.

Integrating edge effects into studies of habitat fragmentation: a test using meiofauna in seagrass

Habitat fragmentation is thought to be an important process structuring landscapes in marine and estuarine environments, but effects on fauna are poorly understood, in part because of a focus on patchiness rather than fragmentation. Furthermore, despite concomitant increases in perimeter:area ratios with fragmentation, we have little understanding of how fauna change from patch edges to interiors during fragmentation. Densities of meiofauna were measured at different distances across the edges of four artificial seagrass treatments [continuous, fragmented, procedural control (to control for disturbance by fragmenting then restoring experimental plots), and patchy] 1 day, 1 week and 1 month after fragmentation. Experimental plots were established 1 week prior to fragmentation/disturbance. Samples were numerically dominated by harpacticoid copepods, densities of which were greater at the edge than 0.5 m into patches for continuous, procedural control and patchy treatments; densities were similar between the edge and 0.5 m in fragmented patches. For taxa that demonstrated edge effects, densities exhibited log-linear declines to 0.5 m into a patch with no differences observed between 0.5 m and 1 m into continuous treatments. In patchy treatments densities were similar at the internal and external edges for many taxa. The strong positive edge effect (higher densities at edge than interior) for taxa such as harpacticoid copepods implies some benefit of patchy landscapes. But the lack of edge effects during patch fragmentation itself demonstrates the importance of the mechanisms by which habitats become patchy.

Contrasting below- and aboveground responses of two deciduous trees to patchy nitrate availability

We investigated how patchy nitrate availability influences growth and functioning of plant roots and generates, through vascular constraints on long-distance transport, aboveground heterogeneity in plant growth and chemistry. We examined two broadleaf tree species, Acer rubrum L. and Betula papyrifera Marsh. Plants were grown either in a split-root setup where a single root received full nutrient supply and the rest of the root system received all nutrients except nitrogen (patchy treatment), or in a single pot with full nutrient supply (homogeneous treatment). In both species, fine roots proliferated in the nitrogen patch, but B. papyrifera produced twice as much fine root biomass in response to patchy nitrate availability as did A. rubrum. There was no difference between treatments in nitrogen uptake rate in either species. In general, specific water uptake was higher in A. rubrum than in B. papyrifera, especially in the nitrogen-rich side pot. When nitrate availability was patchy, nitrate reductase activity in roots and leaves was unaffected in either species. In A. rubrum, but not in B. papyrifera, patchy nitrate supply resulted in aboveground heterogeneity, with leaves above the N-fertilized roots being larger and having a higher relative chlorophyll concentration than those inserted in the opposite quater of the stem.

Investigation and demonstration of the durability of air plasma pre-treatment on polypropylene automotive bumpers

Higher utilisation of low-density materials such as polymers and polymer composites is a pre-requisite for the lightweight vehicle of the future. Of the commodity polymers polypropylene (PP) is by far the most attractive for the automotive industry. Additionally, PP can be utilised as a glass or mineral filled composite which may be used for semi-structural applications.A major problem is that PP (along with other polyolefins) has a non-polar surface chemistry which means the wetting characteristics of components made from this material are poor. Ultimately, this will result in poor adhesion of paints, coatings or adhesive bonding products. This problem has been overcome in the majority of instances by treating the surface of the substrate in order to alter the surface chemistry.PP has found extensive use as films and flat sheets and hence certain techniques such as flame and corona have been favoured despite both having problems of heterogeneous or patchy treatment across a surface. However, for complex 3-D automotive shapes, such as bumpers, these methods are less useful. While flame treatment for example is widely used it has several disadvantages in a commercial volume production environment which all centre around the potential for the part to undergo overtreatment, incipient melting or melting during machine stops etc., as well as the hazards associated with combustible gas. An alternative method is atmospheric plasma pre-treatment.This work has investigated the effect of a forced air plasma pre-treatment on surface chemistry and bond strength of a commercial grade polypropylene material.The plasma head was attached to a robot arm which makes it highly suited to continuous production environments and can treat complex surfaces. A range of translation speeds were investigated and the surface chemistry and topography of the treated surfaces were examined using atomic force microscopy and X-ray photoelectron spectroscopy. The processing was further optimised by single lap-shear testing.An optimised set of parameters was used to pre-treat and bond a full size automotive bumper assembly with a polyurethane (PU) adhesive. Bumpers were then subjected to a standard automotive range of climate conditioning as well as soaking at −20°C and 70°C before front centre impact testing. Parts pre-treated and bonded using this pre-treatment and adhesive system, successfully passed all the required standard automotive impact tests.For added benefit, it was also found that the open time of the pre-treatment was 1 week depending on storage conditions.

Does soil heterogeneity and compaction in ingrowth-cores affect growth and morphology of black spruce fine-roots?

Ingrowth-cores are commonly used in studies of fine-root production in forest stands. However, some concerns have been expressed regarding changes in root growth in the artificial soil environment created in ingrowth-cores. In this study, the effects that homogenization and compaction of soil might have on fine-root growth and morphology of black spruce (Picea mariana Mill.) were examined. Fine-root (<2 mm) morphology was characterized by diameter and internode length. There was no difference in fine-root biomass and morphology between conventional ingrowth-cores (soil sieved and homogenized) and compacted cores (soil density increased by one third). However, fine-root biomass was substantially higher in ingrowth-cores in which the soil was distributed in layers of different fertility (patchy treatment) and both diameter and internode length values were closer to that found in the undisturbed soil cores. In the heterogenous treatment, the root internode length and biomass was significantly higher in rich patches than in poor patches. Our results indicate that fine-root production assessment using conventional ingrowth-cores where the soil is sieved and homogenized may underestimate the true production found in undisturbed soil. Fine-root architectural parameters in the patchy treatment were more similar to those found in the undisturbed soil cores. This study suggests that stratification or increased patchiness of the ingrowth-core growing medium should better mimic the conditions associated in undisturbed soils.

Consequences of Patchy Distribution of Light for the Growth of the Clonal Herb Glechoma Hederacea

The hypothesis that the clonal plant Glechoma hederacea can forage for light in environments with spatially patchy light supply was tested experimentally using artificial habitats in the glasshouse. There were five light treatments. Two treatments were homogeneous, with uniformly low or high light. Three treatments were patchy, each consisting of one high light patch and one low light patch. In the patchy treatments the position of the light patches differed with respect to the position at which the clone commenced growth. Several morphological responses were predicted if foraging for light through morphological plasticity took place : (I) there should be a greater concentration of ramets and biomass, a greater frequency of branching, greater leaf area, a lower proportional allocation of biomass to stolons and a higher proportional allocation of biomass to leaves in high light than in low light patches ; (2) there should be increased petiole lengths and a higher proportional allocation of biomass to stolons and petioles in low light patches than in high light patches ; (3) different primary stolons should assume different morphologies when exposed, simultaneously, to different light regimes. Structures directly involved in light acquisition in G. hederacea showed the greatest responses to changes in light conditions. In the patchy light treatments the frequency of branching, the leaf area of primary ramets and the proportional allocation to leaf biomass were significantly greater in high light patches and petiole length and proportional allocation to petiole biomass were significantly greater in low light patches. The greater leaf area, coupled with greater branching, allowed clones to harvest light energy more efficiently in high light conditions and the increase in petiole length allowed clones to escape from poor light conditions. However, these foraging responses were shown only when clones grew from low light to high light patches or when different primary stolons were exposed simultaneously to either high or low light. Foraging responses were suppressed when clones grew from high light to low light patches. These results imply that responses to patchy light conditions are not clone-wide, but localised within individual stolons, and that individual stolons can adjust morphology rapidly only when high resource patches are encountered after low resource patches. The converse - adjustment to a low resource patch following a period in a high resource patch - does not occur or occurs slowly, due to physiological integration within stolons and the predominantly acropetal nature of resource translocation.

Exploitation of Patchily Distributed Soil Resources by the Clonal Herb Glechoma Hederacea

1 To allow assessment of the ability of plants to exploit heterogeneous habitats, the growth of the stoloniferous herb Glechoma hederacea was compared in three artificial soil environments. In the control treatment named 'uniform', potting compost was evenly mixed with sand; the treatment named 'patchy' contained the same quantity of potting compost, but half was concentrated in a central resource-rich circle in each box. In the treatment named 'low', compost was distributed homogeneously as in the first treatment, but the total quantity of potting compost was halved. 2 The biomass of G. hederacea produced in the patchy treatment was over two and a half times that produced in the uniform treatment, and over ten times that produced in the low treatment. In addition, more leaves were produced in the patchy treatment than in the other two treatments. Almost twice as many stolons reached the perimeters of the boxes. in the patchy treatment as in the uniform treatment. However, the biomass of the portions of the clones that had no basipetal connections via stolons into the central circle did not differ between treatments. 3 There was little evidence that above-ground biomass or ramets were concentrated inside the central circle of the patchy treatment relative to the other two treatments. 4 In contrast, 80% of the root biomass of plants in the patchy treatment was concentrated within the resource-rich central circle. Contrary to the situation in plants grown in homogeneous conditions, root:shoot ratio was highest where soil-derived resources were locally most abundant. Inside the central circle, ramets developed roots earlier in the patchy treatment than in the uniform treatment; outside the central circle, ramets developed roots later in the patchy treatment than in the uniform treatment. 5 In a supplementary experiment the length of young root systems increased exponentially from whatever time their growth was initiated. Thus, local delay or advancement of the initiation of root growth, in response to variations in soil characteristics, could have generated the observed concentration of root biomass inside the central circle of the patchy treatment. 6 G. hederacea can exploit environmental heterogeneity through local functional specialization of plant parts. In many habitats, species that have this ability may outcompete those adapted solely to resource-poor conditions.

Large- and small-scale effects of habitat structure on rates of predation: how percent coverage of seagrass affects rates of predation and siphon nipping on an infaunal bivalve.

Landscape ecology, predominantly a terrestrial discipline, considers the effect of large-scale (tens of meters to kilometers) spatial patterns of habitats on ecological processes such as competition, predation, and flow of energy. In this study, a landscape-ecology approach was applied to a marine soft-sediment environment to examine rates of predation and transfer of secondary production in and around vegetated habitats. Seagrass beds naturally occur in a variety of spatial configurations from patches 1-10s of meters across with interspersed unvegetated sediments (i.e., patchy coverage) to more continuous coverage with little or no bare sediment. I designed experiments to address how percent coverage of seagrass in a 100-m2 area of seafloor, and the spatial arrangement (degree of patchiness or fragmentation) of an equal area (100 m2) of vegetation affected predation (lethal) and siphon nipping (sublethal) intensity on an infaunal bivalve, Mercenaria mercenaria (hard clam). Measures of seagrass density and biomass with different percent coverage of seagrass were also made. When clams were placed in both the vegetated and unvegetated portions of the seafloor nearly twice as many clams were recovered live with 99% seagrass cover than with 23% seagrass cover, while survivorship was intermediate with 70% cover. Cropping of clam siphons from both the vegetated and unvegetated sediments was also affected by the amount of seagrass cover in a 100-m2 area of seafloor: mean adjusted siphon weights were approximately 76% heavier from the 99% seagrass cover treatment than from the 70% or 23% cover treatments. Survivorship of clams placed within an equal area of seagrass in very patchy, patchy, and continuous spatial configurations was 40% higher in the continuous seagrass treatment than in either of the two patchy treatments. This study demonstrates that transfer of secondary production in the form of predation and cropping on an infaunal organism is altered as the percent cover of seagrass changes. While large-scale changes in the amount and spatial patterning of vegetation may affect habitat utilization patterns and foraging HGLoopbehavior, increased seagrass density and biomass with increased percent coverage of seagrass limit any conclusions concerning predator foraging behavior and feeding success in response to patch shapes and sizes. Instead, local changes in seagrass characteristics provide the most compelling explanation for the observed results.