Green Retention Research Articles

The Effect of Denture Cleansing Solutions on the Retention of Precision Attachments: An In Vitro Study.

This study aimed to investigate the effect of different cleansing solutions on the retention of precision attachments. A precision attachment patrix was embedded into acrylic resin and the matrix was placed onto the patrix. The red (high retention, 8 N), yellow (regular retention, 6 N), and green (reduced retention, 4 N) plastic matrixes of the attachments (n = 32) were soaked in three different denture cleansing solutions (sodium laureth sulfate, sodium bicarbonate-sodium perborate, sodium bicarbonate) for a duration simulating 6 months of clinical use. The control group was soaked in tap water. A universal testing machine was used to measure the retention values of attachments after they were soaked in denture cleansers. The retention values were compared among the groups with repeated-measures analysis of variance followed by the Tukey HSD test (p = 0.05). Yellow attachments were affected by sodium laureth sulfate, sodium bicarbonate-sodium perborate, and water (p = 0.012). Green attachments’ retention increased after immersion in sodium laureth sulfate (p = 0.04) and water (p = 0.02). Red attachments’ retention increased after immersion in sodium laureth sulfate or sodium bicarbonate-sodium perborate (p = 0.045). Water did not affect the retention of red attachments. Because sodium bicarbonate tablets did not affect the retention of attachments, clinicians may recommend their use as a cleanser. Clinicians also may inform patients using fixed and removable partial prostheses with precision attachments of a possible increase in retention after the use of sodium laureth sulfate or when using sodium bicarbonate-sodium perborate with yellow and red attachments.

Influence of water storage and plant crop factor on green roof retention and plant drought stress

Green roofs can reduce stormwater runoff with deeper substrates providing greater storage for water retention and evapotranspiration (ET) regenerating storage capacity between rainfall events. In green roof models, ET can be estimated using species-specific plant crop factors (Kc), which characterize water use under non-limiting conditions. We manipulated Kc by altering plant density in a glasshouse experiment under well-watered conditions. We determined Kc of green roof plants growing in pots with different substrate depths (150 mm and 300 mm) and plant densities (0, 1, 2 and 4 plants per pot). We then analyzed the influence of storage and Kc on retention and drought stress using a water-balance model, with a 30-year climate scenario for Melbourne, Australia. We hypothesized that greater planting density and substrate depth would result in proportionally greater ET and therefore higher Kc (glasshouse experiment) and that this would improve retention and reduce drought stress (rainfall simulation). Contrary to our hypotheses, cumulative ET increased by only 38–48% with increased substrate depth and by only 28–38% with increased plant density, despite large increases in plant biomass (67–150%) and growth. Kc values ranged from 1.9–2.2 and 2.7–3.8 for shallower and deeper substrates, respectively. Due to these very high crop factors, our water balance model showed very high annual rainfall retention (97.5%). However, higher Kc and storage only increased rainfall retention by 3–5% and resulted greater drought stress. Plants in deeper substrates experienced 14–29 more days of drought stress, as these plants depleted substrate moisture more efficiently (i.e., had a higher Kc) compared with shallow substrates. These findings suggest that improvements in rainfall retention for green roofs with deeper substrates or higher plant densities are small relative to the increased risk of plant drought stress. The lowest planting density was optimal for improving rainfall retention and reducing plant drought stress.

Right hepatectomy with preservation of the entire caudate lobe in patients with metastatic liver tumors: a case of a new hepatectomy technique and treatment strategy for patients with marginal liver function

BackgroundPerforming major hepatectomy for patients with marginal hepatic function is challenging. In some cases, the procedure is contraindicated owing to the threat of postoperative liver failure. In this case report, we present the first case of marginal liver function (indocyanine green clearance retention rate at 15 min [ICGR15]: 28%) successfully treated with right hepatectomy, resulting in total caudate lobe preservation.Case presentationA 71-year-old man was diagnosed with sigmoid colon cancer with three liver metastases (S5, S7, and S8). All of metastatic lesions shrunk after chemotherapy, but his ICGR15 and indocyanine green clearance rate (ICGK) were 21% and 0.12, respectively. Moreover, the remnant liver volume was only 39%. Therefore, portal venous embolism (PVE) of the right portal vein was suggested. Portography showed divergence of the considerably preserved right caudate lobe branch (PV1R) from the root of the right portal vein. The liver function was reevaluated 18 days after PVE was suggested. During this time, the ICGR15 (21–28%) and ICGK rate (0.12–0.10) deteriorated. The right caudate lobe was significantly enlarged; thus, a total caudate lobe-preserving hepatectomy (TCPRx) was performed. Patients eligible for TCPRx included those with (1) hepatocellular carcinoma or metastatic liver cancer, (2) no tumor in the caudate lobe, (3) marginal liver function (ICG Krem greater than 0.05 if TCPRx was adapted; otherwise, less than 0.05) and Child–Pugh classification category A, and (4) preserved PV1R and right caudate bile duct branch. The procedure was performed through (A) precise estimation of the remnant liver volume preoperatively, (B) repeated intraoperative cholangiography to confirm the biliary branch of the right caudate lobe (B1R) conservation, and (C) stapler division of posterior and anterior Glisson’s pedicles laterally to avoid injuries to the PV1R and B1R.ConclusionsRight hepatectomy with total caudate lobe preservation, following PVE, was a safe and viable surgical technique for patients with marginal liver function.

Development of a Green Color Retention Method for Lactic Acid Fermented “Nozawana”

Development of a Green Color Retention Method for Lactic Acid Fermented “Nozawana”

Ecosystem Management of Eastern Canadian Boreal Forests: Potential Impacts on Wind Damage

Research Highlights: Windthrow can interfere significantly with ecosystem management practices. In some cases, their goal could still be reached but this may prove more complex in other cases, like the partial cutting of old-growth stands. In situations where windthrow is common without any human intervention, the use of partial cutting to maintain some stand structures may lead to a feedback loop leading to additional windthrow. Background and Objectives: Forest ecosystem management using natural disturbances as a template has become the management paradigm in many regions. Most of the time, the focus is on fire regime and effects. However, windthrow can be common in some places or can interfere with practices implemented in an ecosystem management strategy. This paper looks at interactions between ecosystem management and windthrow. Materials and Methods: The paper builds on three case studies looking at various elements that could be part of ecosystem management strategies. The first one looks at the impact of green tree retention, while the second one looks at the impact of reducing the size and dispersing clearcuts, and the last one examines the impact of a range of cutting practices in irregular old-growth stands. Results: Green tree retention leads to increased windthrow, especially when applied within mature even-aged stands. Reducing the size of clearcuts and dispersing them over the landscape also involves substantial windthrow along edges. Partial cutting in old-growth stands can lead to relatively high mortality, but part of it is not necessarily related to wind since it occurs as standing dead trees. Differences in the amount of damage with tree size and species have been found and could be used to reduce wind damage. Conclusions: Approaches to minimize wind damage in ecosystem management can be designed using existing knowledge. However, using windthrow as a template to design management strategies would prove more complex.

From ecological knowledge to conservation policy: a case study on green tree retention and continuous-cover forestry in Sweden

The extent to which scientific knowledge translates into practice is a pervasive question. We analysed to what extent and how ecological scientists gave input to policy for two approaches advocated for promoting forest biodiversity in production forests in Sweden: green-tree retention (GTR) and continuous-cover forestry (CCF). GTR was introduced into forest policy in the 1970s and became widely implemented in the 1990s. Ecological scientists took part in the policy process by providing expert opinions, educational activities and as lobbyists, long before research confirming the positive effects of GTR on biodiversity was produced. In contrast, CCF was essentially banned in forest legislation in 1979. In the 1990s, policy implicitly opened up for CCF implementation, but CCF still remains largely a rare silvicultural outlier. Scientific publications addressing CCF appeared earlier than GTR studies, but with less focus on the effects on biodiversity. Ecological scientists promoted CCF in certain areas, but knowledge from other disciplines and other socio-political factors appear to have been more important than ecological arguments in the case of CCF. The wide uptake of GTR was enhanced by its consistency with the silvicultural knowledge and normative values that forest managers had adopted for almost a century, whereas CCF challenged those ideas. Public pressure and institutional requirements were also key to GTR implementation but were not in place for CCF. Thus, scientific ecological knowledge may play an important role for policy uptake and development, but knowledge from other research disciplines and socio-political factors are also important.

Hönnun og virkni léttra gróðurþaka við íslenskar aðstæður

Green roofs are increasingly being installed cities in Europe as a part of sustainable stormwater systems. The goal of this research was to assess the hydrological efficiency of different configurations of extensive green roofs in Iceland and present suggestions for successful design of such roofs based on local materials and weather conditions. International literature and best design practices were reviewed. Runoff from five test roofs was monitored for 11 months, in conjunction with snowdepth, rainfall, wind and air temperature. Green roof water retention measured highest 85% in June and July in accordance with other studies in cold climates. Water retention measured, however, somewhat lower during the winter (<20%). Significant delay of runoff's center of mass and lowering of peak runoff was measured in all green roofs except during the largest runoff events. Average event water retention was correlated to air temperature, cumulative rain, rain 14 days before event and wind speed 7 days before event. Roofs with moss and sedum turf demonstrated good hydrological efficiency, good appearance and needed little maintenance. Grass turf roofs retained slighlty more water, but were less drought resistant and looked poorly during early summer. Wild, water resistent plants like moss and sedum performed better overall.

Liver function assessment by indocyanine green plasma disappearance rate in patients with intra-abdominal hypertension after “non-hepatic” abdominal surgery

Background and objective: Liver function assessment in patients with intra-abdominal hypertension (IAH) after major abdominal surgery is complex and often confounding. Elevated intra-abdominal pressure (IAP) often occurs after major abdominal surgery, and is associated with decreased abdominal blood flow and organ dysfunction, and it could cause abdominal compartment syndrome (ACS), which is a life-threatening condition. Plasma disappearance rate (PDR) of indocyanine green (ICG) and ICG retention rate after 15 min (R15) were used to evaluate liver function and as a prognostic parameter after major abdominal surgery.Methods: In this prospective/observational study, 51 patients were followed in the surgical intensive care unit after major abdominal surgery (operation of the small and large intestine, stomach, pancreas, spleen, or resection of the abdominal aorta), 29 had IAH. The PDR-ICG and R15 were analyzed 24 h after surgery concurrently with IAP, APP, bilirubin, AST, ALT, prothrombin time, albumin, cardiac index, arterial lactate, oxygen delivery, MAP (mean arterial pressure), APACHE II (acute physiology and chronic health evaluation), SOFA (sequential organ failure assessment), and SAPS II (simplified acute physiology score). IAH has been defined as a peak intra-abdominal pressure (IAP) value of ≥12 mmHg, at a minimum, as two standardized measurements obtained 1–6 h apart.Results: The PDR-ICG measured 24 h after surgery was not different among groups (20.95% [SD = 10.34] vs 25.40% [SD = 7.42]), p = .094. ICG R15 was significantly higher in patients with IAH, 11.10% [SD = 13.82] vs 8.30 [SD = 11.46], p < .05, respectively. The PDR/ICG value was significantly lower in non-survivors than survivors (16.82 [SD = 10.87] vs 24.35 [SD = 8.48], p < .05).Conclusions: The results suggest that PDR/ICG and ICG R15 are useful dynamic tests for evaluation of complex liver function and survival prediction after major abdominal surgery in patients with IAH.

绿地滞尘效应和机理评估进展

绿地滞尘效应和机理评估进展

Breeding bird communities associated with land cover in intensively managed pine forests of the southeastern U.S.

Abstract Intensively managed pine (Pinus spp.) forests (IMPFs) in the southern U.S. are often harvested by clearcutting in conjunction with green tree retention (i.e., retention of unharvested or less-intensively harvested trees and other vegetation), which is thought to promote structural diversity and to benefit wildlife. Management units in IMPFs thus primarily consist of regenerating pine clearcuts (RCCs) plus retained cover in streamside management zones (SMZs: vegetative buffers along perennial and intermittent streams) and/or stringers (forested buffers along ephemeral drains). To understand relationships between retained structures and avian communities, we documented and compared species diversity of breeding bird species and avian guilds in three-year-old RCCs and associated SMZs and stringers on 60 IMPF management units within the South Central Plains ecoregion of the southeastern U.S. We detected 5617 individuals of 60 species. Eight species were considered “common birds in steep decline,” one of which was frequently detected (Prairie Warbler, Setophaga discolor). Three of our 15 most frequently detected species were identified by Partners in Flight as “warranting management attention” for “moderate or high regional declines,” and 19 other species were listed as “warranting management attention” but were uncommonly detected. Forty-two of 44 species documented in RCCs were also observed accessing retention cover areas. SMZs and stringers comprised an average of 17.4% of management unit area, but 27% of species were detected solely in retention cover types. There was an 84% species overlap between SMZs and stringers. Stringers augmented SMZ contributions to site avian diversity by hosting forest specialist guilds. Diversity of early-successional specialists was similar between stringers and RCCs, suggesting stringers also enhanced RCC contributions to site bird diversity. Furthermore, we detected several species only within stringers. Green tree retention land cover contributed to stand scale avian diversity disproportionately to its area, and in particular, stringer cover appeared to enhance the value to avifaunal species diversity of RCC and SMZ patches.

Comparison of Green Color Retention of Zoysiagrass and Cool-season Grass under Multi-layer System, USGA System, and Mono-layer System of Sports Field

Comparison of Green Color Retention of Zoysiagrass and Cool-season Grass under Multi-layer System, USGA System, and Mono-layer System of Sports Field

Dental materials: The multi-stranded wire retainer

Fixed retainers offer many advantages for the orthodontic patient, including reduced need for patient compliance, better aesthetics and long-term stability, with the multi-stranded wire retainer, the gold standard, explains J. I. J. Green Retention is the phase of orthodontics that aims to preserve teeth in their desired positions after active orthodontic treatment and is achieved with fixed or removable retainers. Fixed retainers offer many advantages over the removable type: reduced need for patient compliance, better aesthetics and predictable long-term stability. The first fixed retainer consisted of a stainless steel wire soldered to bands on the canines or premolars but today they are usually bonded to the teeth with light-cured composite. Many materials and wire diameters have been proposed; this article focuses on the multi-stranded wire retainer, which has become the gold standard for maintaining incisor alignment.

Relations between low temperature tolerance and color changes in fall and spring seasons of zoysiagrass (Zoysia japonica Steud.)

AbstractZoysiagrass (Zoysia spp.) is warm season grass used for lawns, golf courses and athletic fields. Although it has better low temperature tolerance compared to other warm season grasses, its longer dormant period than cool season grasses prevents its wide usage in transitional and cooler climate zones. This study analyzed the relationships among low temperature tolerance, green color changes during the fall and spring and the dormant period length among seven Zoysia japonica Steud. cultivars and accessions: two cultivars, four Chinese accessions and one Japanese accession. A relationship between low temperature tolerance and color changes due to dormancy and re‐greening up was examined. Plant samples from the tested Z. japonica were cooled to between −8 and −16°C to measure the lethal temperatures at which 50% of plants died (LT50). These LT50 ranged from −7.3 to −10.1°C, with Lanyin No. 3 having the poorest low temperature tolerance. In the field, the color changes from green to brown for the whole plant in the fall and from brown to green in the spring occurred within 15–20 days as determined by digital analysis from fall 2008 to spring 2010. The fall colors changes (going dormant) on November 8, 2008 and November 7, 2009 were positively correlated with the LT50 (r = 0.824 and 0.823, respectively). The spring colors changes (green‐up) on April 24, 2009 and May 19, 2010 were negatively correlated with the LT50 in both 2009 (r = −0.878) and 2010 (r = −0.869). The dormant period length in 2008–2009 was positively correlated (r = 0.765) with the LT50. This study demonstrated that Z. japonica with poor low temperature tolerance has better green‬‬ retention in the fall but less green color in the spring‬‬. Furthermore, Z. japonica, which became dormant later underwent green up later and had a longer dormant period, mainly due to slower green up in spring.‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬

Multiple low doses of erythropoietin delay the proliferation of hepatocytes but promote liver function in a rat model of subtotal hepatectomy

The impact of various doses of erythropoietin (EPO) on liver regeneration after partial hepatectomy (PH) in different animal models is still under debate. We investigated the impact of low doses of EPO on liver regeneration in a rat model of subtotal hepatectomy. We established a 90 % PH rat model with perioperative injections of low-dose EPO (1,000 IU/kg). We analyzed survival and hepatocyte proliferation in animals treated with or without EPO and assessed liver function by blood ammonia measurement and the indocyanine green 15-min retention test. Low doses of EPO treatment improved the survival of rats after 90 % PH. Unexpectedly, during the first 24 h after the operation, liver regeneration in the EPO-treated rats was inhibited. DNA synthesis, cell proliferation, and the expression of cyclins and p-STAT3 peaked 48 h after PH, which was delayed by about 24 h vs. the control rats. Furthermore, EPO treatment increased the serum level of IL-6 and protected the hepatocytes from apoptosis. Low doses of EPO do not stimulate early hepatocyte proliferation in the regenerating liver, but contribute to liver protection by inducing IL-6 and inhibiting apoptosis.

Morphological and Physiological Measurement of the Stay-Green Trait in Transgenic and Non-Transgenic Cassava under Green-House Water Stress Conditions

Drought stress is the major abiotic factor that limits cassava productivity in many agro-ecological regions of sub-saharan Africa. In this study, stay-green trait in two transgenic cassava genotypes (transformed with isopentenyl transferase (ipt) gene for improved drought tolerance) and six non-transgenic cassava genotypes were evaluated under green-house condi- tions. Leaf abscission (for leaf retention), elongation of the last internodes, photosynthetic rates, and stomatal conductance were determined in these cassava genotypes subjected to three levels of water stress treatments (0, 30, and 60 %) and a positive control or fully irrigated plants. Two non transgenic genotypes (98-0002 and 98-2226) and one transgenic line (529-48) that expressed relatively high level of stay green or leaf retention, also exhibited significantly higher photosynthetic rates, internode elongation and relatively low stomatal conductance compared to other genotypes. Non transgenic genotypes 91-02322 and TME-3 and transgenic line 529-28, expressed moderate levels of stay green and non transgenic genotype 95-0306 and wild type TMS 60444 (for the transgenic lines) were highly susceptible to the water stress treatments. The results reported here showed there was a positive correlation between leaf retention, photosynthetic rates, internode elongation and stomatal conductance.

Cost-effectiveness of silvicultural measures to increase substrate availability for wood-dwelling species: A comparison among boreal tree species

This study analysed the cost-effectiveness of silvicultural measures that increase substrate availability for saproxylic (wood-dwelling) species. Mixed stands of Norway spruce (Picea abies L.), Scots pine (Pinus sylvestris L.) and birch (Betula pubescens Ehrh and Betula pendula Roth) or aspen (Populus tremula L.) in three regions of Sweden were modelled. Inverted cost-effectiveness was calculated by dividing the economic cost associated with a silvicultural measure by the increase in coarse woody debris (CWD) and an index reflecting substrate availability for red-listed saproxylic beetles and cryptogams, compared with a reference scenario maximizing economic profit. Tree species had a large impact on the cost-effectiveness of green tree retention: Scots pine was the most costly tree species to retain and aspen and birch the most cost-effective. Tree species also had an impact, albeit smaller, on the cost-effectiveness of the creation of high stumps. It was most cost-effective to create high stumps from birch and aspen in southern Sweden, whereas in northern Sweden it was more cost-effective to create high stumps from pine and spruce. Therefore, when increasing the amount of coarse woody debris (CWD), deciduous trees should be targeted in southern Sweden more than in the north. However, it is important that CWD is created from all tree species, because different tree species support different assemblages of saproxylic species. As regards measures that are not associated with particular tree species, retention of snags at final harvest is a cost-effective measure in all regions, whereas increasing the rotation period is costly.

Natural dynamics-based silviculture for maintaining plant biodiversity in Populus tremuloides-dominated boreal forests of eastern CanadaThis article is one of a selection of papers published in the Special Issue on Poplar Research in Canada.

Southern boreal forests dominated by trembling aspen ( Populus tremuloides Michx.) are notable for the biological richness of their plant communities. We used 12 plant community and plant functional group indicators to test the hypothesis that natural dynamics-based silvicultural systems better maintain biodiversity in aspen plant communities than conventional clear-cutting. Using CA ordination, box-and-whisker diagrams, and ANOVA, we compared the range of variability of our 12 bioindicators among five experimental stand types of the sylviculture et aménagement forestier écosystémiques (SAFE) project: mature (78 years) uncut; mature 1/3 partial-cut; mature 2/3 partial-cut; young (3 years) unburned clear-cut; young burned clear-cut; and three closely matched aspen stand types of northwest Quebec and northeast Ontario: old (105 years) uncut; young unburned clear-cut; young wildfire. Burned clearcuts partially emulated wildfires by reducing tall shrub abundance and regenerating post-fire specialists, but snags were lacking. The dual disturbance also retarded aspen regrowth and caused a 7-fold increase in non-native plants. Partial-cuts retained most attributes of mature uncut stands, but after 3 years showed little evidence of accelerating development of old stand characteristics. We concluded that SAFE natural dynamics-based silviculture better recreated the range of variability of naturally disturbed aspen plant communities than conventional clear-cutting. Improvements, including alternative burn prescriptions and snag or green tree retention in clearcuts, are nontheless warranted.

Soil disturbance and five-year tree growth in a montane alternative silvicultural systems (MASS) trial

Ground-based forestry practices can negatively affect soil productivity by altering the physical, chemical, and biological properties of soil. The effect of soil disturbance on soil properties and tree growth was evaluated following single-pass hydraulic excavator and multiple-pass combined excavator and flexible track grapple skidder forwarding in four silvicultural systems treatments: Clearcut (CC), Green Tree Retention (GT), Patch Cut (PC), and Uniform Shelterwood (SW). The effectiveness of an excavator soil-rehabilitation technique (tilling) in decompacting skidtrails (i.e., reducing soil bulk density) and nutrient availability was also evaluated. Western hemlock (Tsuga heterophylla (Raf.) Sarg.) and amabilis fir (Abies amabilis Dougl. Ex. Forbes) seedlings were planted on undisturbed plots, within tracks and between tracks of skidtrails, and in rehabilitated trails within the four harvesting treatments in the spring of 1994. Seedling growth was measured after five growing seasons, and nutrient concentrations of current-year foliage were determined at the end of the fourth growing season. Seedling survival and growth was generally reduced by soil disturbances associated with skid-trails. Effects of disturbance on physical properties of soil (e.g., compaction, puddling) and disruption of drainage were the most likely causes. Nutrient deficiencies do not appear to be a factor. Nonetheless, nitrogen concentrations were lower in current-year foliage taken from rehabilitation treatments than from either undisturbed or skidtrail treatments. Effectiveness of soil rehabilitation varied. In well-drained deeper soils, tilling reduced soil bulk density to levels below those of undisturbed soils and, in the short-term (five years), improved tree growth. In wetter conditions, rehabilitation treatment decreased survival and growth of both species. Thus specific rehabilitation (tilling) prescriptions should not be universally applied across a landscape. Key words: Abies amabilis, Tsuga heterophylla, foliar analysis, soil bulk density, soil compaction, soil rehabilitation

Above-ground biomass predicts growth limitation in amabilis fir and western hemlock seedlings

Conifer regeneration on clearcut montane sites is frequently affected by post-planting growth stagnation. The ability to predict such stagnation would be a valuable asset to forest managers. In this study, we tested the usefulness of above-ground biomass and photosynthetic efficiency (as estimated by foliar nitrogen concentration) in diagnosing growth limitations in western hemlock (Tsuga heterophylla) and amabilis fir (Abies amabilis). Seedlings were grown under different silvicultural systems (clearcut, patch cut, green tree retention and shelterwood) and post-planting treatments (fertilization, vegetation removal) at the Montane Alternative Silvicultural Systems (MASS) site on Vancouver Island, BC. Foliar nitrogen was found to be a poor predictor of height and stem volume growth. However, above-ground biomass predicted current height and stem volume (year 3 after planting), as well as future stem volume (year 7 after planting), in both species. Above-ground biomass therefore represents a useful measure of likely future growth performance, and may provide early warning of incipient growth stagnation in these species. Key words: amabilis fir, Abies amabilis, biomass, western hemlock, Tsuga heterophylla, growth limitation, photosynthetic capacity, biomass, seedling growth, regeneration

Green Tree Retention in Fennoscandian Forestry

Green Tree Retention in Fennoscandian Forestry