Influence of herbaceous ground cover on forest restoration of eastern US coal surface mines

Competitive effects of dense herbaceous vegetation (ground cover) can inhibit forest restoration on mine sites. Here we review the evidence of ground cover interactions with planted tree seedlings on coal surface mines of the eastern US, discuss recent research into these interactions, and draw conclusions concerning ground cover management when restoring forests on reclaimed coal mines. Reclaimed mine sites have a high potential to support productive forests, however forest establishment is inhibited by reclamation practices that included soil compaction, and the seeding of competitive ground covers. In the first few years after tree planting, a dense ground cover of grass and legume species commonly seeded on mine sites often affect growth and survival negatively. Herbaceous vegetation providing less extensive and competitive ground coverage may either facilitate or inhibit tree establishment, depending on site conditions. The use of quality planting stock promotes the competitive ability of seedlings by improving nutrient status and the ability to capture available resources. Herbaceous species have contrasting functional characteristics, and thus compete differently with trees for available resources. Negative interactions with trees are more frequently reported for non-native cool-season grasses than for native warm-season grasses, while the effects of legumes change over time. Further research is needed to fully understand the mechanisms of tree/ground cover interactions. The development of seeding mixes that can control erosion, facilitate survival and growth of planted trees, and allow establishment by unplanted native species would aid forest restoration on eastern US, coal mines.

     

Mesenchymal stem cells and bone regeneration

OBJECTIVE: To review the role of mesenchymal stem cells (MSC) in bone formation and regeneration, and outline the development of strategies that use MSC in bone healing and regeneration. STUDY DESIGN: Literature review. METHODS: Medline review, synopses of authors' published research. RESULTS: The MSC is the basic cellular unit of embryologic bone formation. Secondary bone healing mimics bone formation with proliferation of MSC then their differentiation into components of fracture callus. Bone regeneration, where large amounts of bone must form, mimics bone healing and can be achieved with MSC combined with strategies of osteogenesis, osteoinduction, osteoconduction, and osteopromotion. MSC based strategies first employed isolated and culture expanded stem cells in an osteoconductive carrier to successfully regenerate a critical segmental defect in the femur of dogs, which was as effective as autogenous cancellous bone. Because MSC appeared to be immunologically privileged, a study using mismatched allogeneic stem cells demonstrated that these cells would regenerate bone without inciting an immunologic response, documenting the possibility of banked allogeneic MSC for bone regeneration. A technique was developed for selectively retaining MSC from large bone marrow aspirates at surgery for bone regeneration. These techniques utilized osteoconductive and osteoinductive carriers and resulted in bone regeneration that was similar to autogenous cancellous bone. CONCLUSION: MSC can be manipulated and combined with carriers that will result in bone regeneration of critically sized bone defects. CLINICAL RELEVANCE: These techniques can be employed clinically to regenerate bone and serve as an alternative to autogenous cancellous bone.     

Impact of Agronomic and Storage Practices on Acrylamide in Processed Potatoes

Acrylamide is a probable carcinogen found in processed potato products. The compound is formed at elevated temperatures by the Maillard reaction from two primary precursors - reducing sugars (fructose and glucose) and asparagine. Significant advances have been made in reducing acrylamide formation by selecting varieties with low precursor concentrations through conventional breeding or genetic modification techniques. However, acrylamide in many of the traditional varieties processed for fries or chips is sometimes found at elevated levels. Both agronomic and storage practices can significantly influence glucose, fructose, and asparagine concentrations and therefore the potential to form acrylamide during processing. This summary of a symposium presentation given at the 99th Annual Potato Association of American Meeting is to provide a general overview of previous studies that have examined the effects of agronomic factors such as nutrient and water management and storage factors such as temperature and duration on acrylamide precursors and/or acrylamide in processed potato products. A better understanding of how these factors affect acrylamide precursors is a first step in minimizing acrylamide formation during processing and improving the quality of processed potato products.     

Radiographic findings in dogs with pulmonary blastomycosis: 125 cases (1989-2006)

OBJECTIVE: To identify radiographic patterns in dogs with pulmonary blastomycosis and radiographic factors associated with outcome. DESIGN: Retrospective case series. ANIMALS: 125 dogs with pulmonary blastomycosis. PROCEDURES: Medical records were reviewed, and for each lung lobe, the primary radiographic pattern and percentage of lobar involvement at the time of initial examination were recorded. RESULTS: 79 dogs survived, 38 died, and 8 were euthanized without treatment. The initial radiographic pattern was variable and not significantly associated with outcome. Mean half-time for radiographic resolution of pulmonary infiltrates was 41.4 days for all patterns except masses, for which mean half-time to resolution was 90.8 days. Transient radiographic worsening was seen in 20 of 87 (23%) dogs but was not associated with a poor prognosis. Pulmonary bullae were seen in 20 (16%) dogs, most often in association with an alveolar pattern. Accuracy of using percentage of right caudal lung lobe involvement ( 20%) to predict outcome was 74.4%; accuracy of using number of affected lobes (< 4 vs >or= 4) to predict outcome was 65.8%. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that a nonuniform distribution of pulmonary infiltrates was equally as likely as a diffuse nodular interstitial pattern in dogs with pulmonary blastomycosis. On the basis of half-time for resolution of pulmonary infiltrates, follow-up radiography should be performed no more often than every 4 to 6 weeks in clinically stable patients. Transient radiographic worsening that occurred during the initial weeks of treatment was not associated with a poorer prognosis.     

First account of the metazoan parasite fauna of oilfish Ruvettus pretiosus Cocco, 1829 (Perciformes: Gempylidae) in South African waters

Parasites are an important but neglected component of ecosystems that can be used as indicators of host biology and ecology. In the present study, the metazoan parasite assemblage of Ruvettus pretiosus, an understudied but widely distributed predatory gempylid, caught off South Africa was surveyed. A total of seven parasite taxa, including four new infection records (Bolbosoma capitatum, Rhadinorhynchus sp., Hepatoxylon trichiuri and Anisakis sp.), two new locality records (B. capitatum and Rhipidocotyle sp.) as well as the ectoparasitic copepod Sagum foliaceus and the cestode Tentacularia coryphaenae were recovered from the eight specimens examined.     

Glomalin-related soil protein: Assessment of current detection and quantification tools

Despite the widely acknowledged importance of arbuscular mycorrhizal fungi (AMF) in soil ecology, quantifying their biomass and presence in field soils is hindered by tedious techniques. Hence biochemical markers may be useful, among which glomalin-related soil protein (GRSP) could show a particular promise. Presently GRSP is operationally defined, its identification resting solely on the methods used to extract it from soil (citric acid buffer and autoclaving) and the assays (Bradford/enzyme-linked immunosorbent assay (ELISA) with a monoclonal antibody) utilized to detect it. The current assumption is that most non-heat stable soil proteins except glomalin are destroyed during the harsh extraction procedure. However, this critical assumption has not been tested. The purpose of this research was to challenge the GRSP extraction process to determine the accuracy of the Bradford method as a measure of glomalin; and to provide some assessment of the specificity of the ELISA monoclonal antibody. In two studies we spiked soil samples either with known quantities of a glycoprotein (BSA: bovine serum albumin) or with leaf litter from specific sources. After extraction 41-84% of the added BSA was detected with the Bradford method. This suggests that the currently used extraction procedure does not eliminate all non-glomalin proteins. Also, ELISA cross-reactivity against BSA was limited, ranging from 3% to 14%. Additions of leaf litter also significantly influenced GRSP extraction and quantification suggesting that plant-derived proteins, as would occur in the field, had a similar effect as BSA. Litter additions decreased the immunoreactive protein values, suggesting interference with antibody recognition. We conclude that the use of GRSP, especially Bradford-based detection, in the assessment of AMF-derived substances within field soils is problematic, it may be inappropriate in situations of significant organic matter additions.     

A delay-differential model for representing small pelagic fish stock dynamics and its application for assessing alternative management strategies under environmental uncertainty

We present a novel adaptation of the classic discrete delay-difference model, a continuous delay-differential model (cDDM), which can adequately represent population dynamics of stocks that turn over rapidly and continuously over time (e.g., small pelagic fish, small tunas, and shrimps). We used the Northern-Central Peruvian anchoveta stock (Engraulis ringens, Engraulidae) as a case study for implementing the cDDM and conducted a management strategy evaluation (MSE) through stochastic optimization in policy space (SOPS). Our results showed that cDDM integrated with SOPS efficiently searches optimum and near-optimum harvest control rules (HCR) and is an alternative to pre-setting arbitrary HCRs as in traditional MSE. The cDDM showed comparable stock biomass and recruitment estimate reconstructions to more complex stock assessment models described for anchoveta. We concluded that the anchoveta stock is sustainably managed and is an example of adaptive fisheries management under high ocean-climate variability and uncertainty. Contrary to fishery textbooks, the anchoveta's collapse was not entirely due to the 1972 El Niño (EN) but a recruitment failure preceding EN. Our reconstructions revealed that low recruitment (or recruitment failure) could still occur at high stock biomass. Anchoveta's stock biomass is larger than pre-collapse, likely due to favourable environmental conditions (a cooling trend) and management, despite more frequent and stronger EN events. SOPS quickly revealed that harvest strategies with large base biomass (>5 mmt) lead to higher interannual stock variability and would not produce substantial increases in long-term yield. Alternative HCRs with lower base biomass, while adjusting for productivity regimes, have similar long-term yields without affecting the long-term average stock.     

Astaxanthin profiles and corresponding colour properties in Australian farmed black tiger prawn (Penaeus monodon) during frozen storage

The colour of commercial cooked black tiger prawns (Penaeus monodon) is a key quality requirement to ensure product is not rejected in wholesale markets. The colour, due to the carotenoid astaxanthin, can be impacted by frozen storage, but changes in colour or astaxanthin profile, during frozen storage, have not been studied in detail. Subsequently in this study, the aims were to define the astaxanthin (as cis, trans, mono‐ester and di‐ester forms) content, together with the colour properties, in both pleopods (legs) and abdominal segments. Changes in astaxanthin content and colour properties were further determined during frozen storage (?20°C). Total astaxanthin content was seen to decrease in all samples over time, with the rate of degradation being significantly greater (P < 0.05) in pleopods than abdomen. In both pleopods and abdomen, rate of degradation of esterified forms was significantly greater (P < 0.05) than non‐esterified forms. Hue angle (increase), a* value (decrease) and L value (increase) were all seen to significantly change (P < 0.05) during storage, with changes being more prevalent in the pleopods. The pleopods are the key indicator of astaxanthin and colour loss in cooked black tiger prawns and preservation strategies are required to preserve astaxanthin and colour during frozen storage.     

Effects of cyclophotocoagulation with a neodymium:yttrium-aluminum-garnet laser on corneal sensitivity,intraocular pressure,aqueous tear production,and corneal nerve morphology in eyes of dogs

OBJECTIVE: To determine effects of cyclophotocoagulation via administration of 100 J with a neodymium:yttrium aluminum garnet (Nd:YAG) laser on corneal touch threshold (CTT), intraocular pressure (IOP), aqueous tear production, and corneal nerve morphology in eyes of dogs. ANIMALS: 15 dogs. PROCEDURE: Noncontact Nd:YAG laser was transsclerally applied (10 applications; 25 W for 0.1 seconds for each application to each of 4 quadrants) to the ciliary body of the left eye of 15 dogs; the right eye was the control eye. Corneal integrity, CTT, tear production as measured by the Schirmer tear test (STT), and IOP were evaluated for 14 days following laser treatment. On day 14, dogs were euthanatized, eyes harvested, and corneas stained with gold chloride. Major nerve bundles were analyzed by use of a drawing tube attached to a light microscope, and maximum diameters were measured by use of image analysis software. RESULTS: All laser-treated eyes had significantly higher CTT values, compared with control eyes. Six of 15 laser-treated eyes developed ulcerative keratitis. On most days, IOP was significantly lower in laser-treated eyes in both morning and evening. Laser-treated eyes had a significant decrease of approximately 1 nerve bundle/corneal quadrant. Values for STT or nerve bundle diameters did not differ significantly. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of 100 J with a Nd:YAG laser effectively reduced IOP while increasing CTT and caused a significant decrease in number, but not diameter, of major corneal nerve bundles. Nerve damage and corneal hypoesthesia are etiologic factors in ulcerative keratitis following Nd:YAG cyclophotocoagulation.     

Distribution of sulphur fractions in lysimeters previously treated with sulphuric acid,NPK fertilizer and a combination of acid and fertilizer

The retention of applied ³⁵S was studied in a lysimeter experiment, in which the lysimeters, consisting of soil columns with intact field and groundlayer vegetation, had previously been treated with either sulphuric acid, NPK or a combination of sulphuric acid and NPK.³⁵S was applied as Na₂³⁵SO₄ to all lysimeters in an amount corresponding to 2 kg S ha^?1, 3 months before the termination of the experiment. Of the applied ³⁵S, 4.7 ± 1.6% (the error term showing the standard error of the mean) was leached from the lysimeters; ³⁵SO₄^2?, was preferentially sorbed in the upper part of the B horizon, >61% being sorbed in the B horizon as a whole. The influence of previous treatments was seen in SO₄^2? content in the B horizon and also in the SO₄^2? concentrations in the leachates from the lysimeters. Sorption of ³⁵SO₄^2? was enhanced by the acid treatment in the A₀ and A₁/A₂ horizons. Ratios between water-extractable SO₄^2? and KCl-extractable SO₄^2? varied from 0.88 in the A₁/A₂ horizon to 0.46 in the lower part of the B horizon, indicating a preferential sorption of less available SO₄^2? fractions in that part of the soil.Significant positive correlations between soil organic carbon and various sulphur fractions, both labelled and unlabelled, indicated the importance of biological S transformations in the A₀ and A₁/A₂ horizons.Positive correlations between KCl-extractable Al and KCl-extractable SO₄^2? were found in the B horizon. Equilibrium calculations suggested that the SO₄^2? activity and Al³⁺ activity in leachates from control and acidified lysimeters were within the stability fields of basaluminite (Al₄(OH)₁₀SO₄), activities in leachates from the latter group of lysimeters, also being close to jurbanite (Al(OH)SO₄).