Dry Weight Data Research Articles

Confirmation of synthetic auxin herbicide resistance in a green pigweed (Amaranthus powellii) population from Ontario, Canada

Abstract Following the application of MCPA/MCPB at 1.7 kg ae ha−1 at a field site near Dresden, ON, Canada, poor control (<50% visible control) of green pigweed (Amaranthus powellii S. Watson) was observed. Amaranthus powellii is a common weed in Ontario crop production, and its evolution of resistance to synthetic auxin herbicides (SAHs) could pose a risk to crop yields. The suspected resistant A. powellii population (R) was used in dose–response and field experiments to determine resistance to SAHs. The objective of these studies was to determine whether this population of A. powellii is resistant to MCPA and cross-resistant to other SAHs. The GR50 (herbicide dose that causes a 50% reduction in plant aboveground biomass) values were determined by fitting plant dry weight data, obtained following application with seven SAHs, to a four-parameter log-logistic equation and were compared between the suspected-resistant (R) population and a known susceptible (S) population of A. powellii. The field trial was conducted in 2017, 2018, 2019, and 2021 in corn (Zea mays L.) and consisted of 11 postemergence SAH treatments. The GR50 values differed between the R and S populations following application with MCPA, aminocyclopyrachlor, dichlorprop-p, and mecoprop, resulting in resistance factors of 4.4, 3.0, 2.5, and 2.4, respectively. In the field study, dicamba and MCPA ester controlled A. powellii 84% and 30%, respectively, at 8 wk after treatment application (WAA). The control of Amaranthus powellii with all SAHs applied POST in corn was poor (<90% visible control) at 8 WAA. Both studies confirmed resistance to SAHs in this population of A. powellii, which will create limitations for farmers aiming to control this weed.

Response of Tahitian Bridal Veil (Gibasis pellucida) and Small-Leaf Spiderwort (Tradescantia fluminensis) to Postemergence Herbicides under Greenhouse Conditions.

Tahitian bridal veil (Gibasis pellucida) and small-leaf spiderwort (Tradescantia fluminensis) are both invasive species in natural areas throughout Florida. However, very little is known regarding herbicide control. To provide land managers with herbicidal control options for both species, postemergence herbicides were evaluated for efficacy in a greenhouse to identify herbicide options that control both species under similar settings. Four herbicides, including triclopyr acid, triclopyr amine + 2,4-D amine, triclopyr amine, and glufosinate were applied at standard label rates and compared to a non-treated control group for efficacy. Visual control ratings were taken at 2, 4, and 8 weeks after treatment (WAT), and shoot dry weights (WAT 8) and regrowth dry weights (WAT 12) were determined. Triclopyr (acid and amine) generally provided the most consistent control of both species as evidenced by the visual control ratings and shoot dry weight data which showed reductions of 76% to 89% in shoot biomass at trial conclusion. Triclopyr + 2,4-D reduced shoot dry weights by 52% to 54% and was the least effective when considering the control of both species.

The effect of plant growth regulator bacteria on micro propagation of grapevine rootstock with three different rooting abilities

In the study, 3 American rootstocks (110 R, 1103 P and 5 BB) with low, medium, and high rooting ability were used, 2 different bacterial isolates Bacillus cereus (ZE-7) and Pseudomonas putida (ZE-12) and their binary combination and the bottom of the cuttings. It was aimed to determine the effect of bacteria on rooting by treating the rooting part. During the rooting stage, hormone-free MS medium was treated with PGPRs, and in addition, hormone-free MS medium containing 1 mgl-1 IBA was used to determine the effects of PGPRs strains. At the end of the study, the root ratio of the explants was maintained; root length, number of roots, root fresh weight, root dry weight, shoot length, shoot fresh weight, and shoot dry weight data were examined. It was determined that PGPR applications generally gave higher values than control and IBA applications. Among the rootstocks, it was determined that they gave the best results in terms of root development. The highest values were obtained in the 5BB rootstock, and the lowest values were generally obtained in the 110R rootstock. Shoot development values varied according to the rootstocks and applications. In terms of the effects of the applications on root development, the highest rooting rate was 72.03%, the highest root number ratio was 1.95 on average, and the highest root fresh weight was 39.75 mg from the Bacillus Cereus application; Additionally, the highest root dry weight was obtained from B.cereus+P.putida application with 13.06 mg. The research highlighted this feature of 5 BB rootstock, which is considered among the easily rooting rootstocks, with its PGPR effect. 110 R, which is known as a difficult rooting rootstock and has high resistance to drought and active lime, which are the biggest threats today, showed a lower rooting rate, but when the values were examined, it was above the control and IBA applications.

The Effect of Irradiation Methods on Biomass Yield on Mix of Corn (zea mays) and Mung Bean (Vigna radiata) with Hydroponic system

The objectives of this research was to find effect of irradiation methods on the production of biomass fresh weight, leaf and root dry weight on combination of mung bean and corn with hydroponic system. This research was design with experimental method using Completely Randomized Design with 2 treatmens and 9 replications. The observed of P1 = irradiation method with the sunlight for 12 hours and P2 = irradiation method with LED grow light 7. watt for 16 hours. Parameters observed were biomass fresh weight, leaf and root dry weight Data were analyzed using of two samples Independent T-tes. The result showed that biomass fresh weight and leaf dry weight of irradiation with LED higher than irradiation with the sunlight, the average’s 3155,844 g/m2, and 55,14 g/m2, but no significant effect on dry weight of root.

Experimental kS estimation: A comparison of methods for Corynebacterium glutamicum from lab to microfluidic scale.

Knowledge about the specific affinity of whole cells towarda substrate, commonly referred to as kS , is a crucial parameter for characterizing growth within bioreactors. State-of-the-art methodologies measure either uptake or consumption rates at different initial substrate concentrations. Alternatively, cell dry weight or respiratory data like online oxygen and carbon dioxide transfer rates can be used to estimate kS . In this work, a recently developed substrate-limited microfluidic single-cell cultivation (sl-MSCC)method is applied for the estimation of kS values under defined environmental conditions. This method is benchmarked with two alternative microtiter plate methods, namely high-frequency biomass measurement (HFB)and substrate-limited respiratory activity monitoring (sl-RA).As a model system, the substrate affinity kS of Corynebacterium glutamicum ATCC 13032 regarding glucose was investigated assuming a Monod-type growth response. A kS of <70.7 mg/L(with 95% probability) with HFB, 8.55 ± 1.38 mg/Lwith sl-RA, and 2.66 ± 0.99 mg/L with sl-MSCC was obtained. Whereas HFB and sl-RA are suitable for a fast initial kS estimation, sl-MSCC allows an affinity estimation by determining tD at concentrations less or equal to the kS value. Thus, sl-MSCC lays the foundation for strain-specific kS estimations under defined environmental conditions with additional insights into cell-to-cell heterogeneity.

A Seinhorst Model Determined the Host-Parasite Relationships of Meloidogyne Javanica Infecting Fenugreek Cv. UM202.

Root-knot nematodes (RKNs) have been shown to be challenging and persistent pests of economic crops worldwide. Among RKNs, Meloidogyne javanica is particularly important, as it rapidly spreads and has a diverse host range. Measuring its damaging threshold level will help us to develop management strategies for adequate plant protection against nematodes. In our study, we observed the relationship between a linear series of 12 initial population densities (Pi) of M. javanica, i.e., 0, 0.125, 0.25, 0.5, 1, 2, 4, 8, 16, 32, 64, and 128 second-staged juveniles (J2s) g-1 soil, and fenugreek cv. UM202 growth parameters were investigated using a Seinhorst model. A Seinhorst model was fitted to shoot length and dry weight data for fenugreek plants. A positive correlation was found between J2s inoculum levels and percent reductions in growth parameters. The 1.3 J2s of M. javanica g-1 soil were found to damage threshold levels with respect to shoot length and shoot dry weight of fenugreek plants. The minimum relative values (m) for shoot length and shoot dry weight were 0.15 and 0.17, respectively, at Pi =128 J2s g-1 soil. The maximum nematode reproduction rate (Pf /Pi) was 31.6 at an initial population density (Pi) of 2 J2s g-1 soil.

Morpho-physiological characteristics of corn (Zea mays L.) affected by drought during its vegetative stage

Objective: To evaluate the response corn hybrids have on their growth of aerial and root parts, transpiration,and water use efficiency during their early vegetative stage in irrigation and drought conditions.Design/methodology/approach: A randomized complete block design with a factorial arrangement, threerepetitions, three corn hybrids and two humidity levels were used. The evaluated variables were: plant height,leaf area, root length, dry weight of the aerial and root part of the plants, efficiency in the water use and totalplant transpiration.Results: The leaf area and dry weight data of the aerial parts of the assessed plants were greater in irrigationthan in drought; in contrast, root length, dry root weight and water use efficiency were higher in drought. SV 3245 registered a higher total transpiration per plant; SV 3243 and ASGROW 7543 showed higher dry weight in their aerial parts; ASGROW 7543 accumulated a greater dry weight at their roots and was more water usage efficient. The experiments indicated interaction for root length, dry root weight and efficiency in water use.Limitations on study/implications: The drought caused seedlings’ death at 28 days after sowing (dds), therefore, it was not possible to continue the evaluations from then on.Findings/conclusions: The drought decreased the growth of the aerial parts of the plants and increased the root system and efficiency in their water usage.

Sensory characterization of two California-grown avocado varieties (Persea americana Mill.) over the harvest season by descriptive analysis and consumer tests.

In this work, descriptive analysis (DA) and consumer panels were conducted on "Hass" and "3-29-5" (GEM® ) avocados, grown in southern California. Both panels encompassed at least five time points across the 2019 harvest season. The DA panel identified and evaluated overall richness, creamy, smooth, watery, oily, sweet, bitter, umami, salty, astringent, buttery, nutty, and green. The texture attributes received the highest scores in both "Hass" and "3-29-5." Both varieties increased in richness, creaminess, and oiliness at harvests 5 and 6. The consumer panel found that "3-29-5" showed more changes in its eating experience over the season than "Hass," which agreed with dry weight data collected in a simultaneous analytical study. Correspondence analysis indicated that "Hass" samples had a consistent sensory profile over the harvest season, whereas "3-29-5" changed substantially, becoming more closely associated with a positive eating experience late in the harvest season. This is the first work to characterize avocado flavor over the harvest season using both trained and consumer sensory panels. PRACTICAL APPLICATION: Many aspects of avocado were found to have some impact on flavor, but textural properties were by far the most important in determining how well the fruit was liked. This information will be useful in future taste evaluations of avocado and the ongoing development of new avocado varieties.

One-year intradialytic leg exercises with resistance bands and fat mass increase in elderly hemodialysis patients: a retrospective study

BackgroundIntradialytic exercises are recommended to be available as a treatment for enhancing physical functioning. However, there have been few reports which evaluated the results of long-term mild intradialytic exercises in elderly patients. The purpose of this study is to investigate the changes in body weight, body composition, and laboratory data in elderly hemodialysis patients after 1-year intradialytic leg exercises with resistance bands.MethodsA retrospective study. Twenty-one outpatients, aged 65 or older (mean ± SD, 75.2 ± 5.1 years), received intradialytic leg exercises with resistance bands for a year were analyzed. The values of dry weight, body composition, and laboratory data were collected from the year-ago period, at baseline and 1 year after baseline. Fat and muscle mass were evaluated by using a multi-frequency bioimpedance device.ResultsPhysical performance changed and body weight increased after 1-year resistance band exercises. However, the participants gained fat mass, not muscle mass. Although the changes in biochemical data related to protein intake were equivocal, triglyceride levels increased significantly after 1-year exercises. An elevation in serum creatinine levels was observed, even if solute clearance increased significantly.ConclusionsOne-year intradialytic leg exercises with resistance bands may have a potential clinical benefit for body mass index even in elderly hemodialysis patients. However, optimal dietary modification is needed to achieve a balanced increase of muscle and fat mass. An increase of serum creatinine levels does not always mean muscle mass hypertrophy.

Real-time, non-destructive and in-field foliage yield and growth rate measurement in perennial ryegrass (Lolium perenne L.)

BackgroundIn-field measurement of yield and growth rate in pasture species is imprecise and costly, limiting scientific and commercial application. Our study proposed a LiDAR-based mobile platform for non-invasive vegetative biomass and growth rate estimation in perennial ryegrass (Lolium perenne L.). This included design and build of the platform, development of an algorithm for volumetric estimation, and field validation of the system. The LiDAR-based volumetric estimates were compared against fresh weight and dry weight data across different ages of plants, seasons, stages of regrowth, sites, and row configurations.ResultsThe project had three phases, the last one comprising four experiments. Phase 1: a LiDAR-based, field-ready prototype mobile platform for perennial ryegrassrecognition in single row plots was developed. Phase 2: real-time volumetric data capture, modelling and analysis software were developed and integrated and the resultant algorithm was validated in the field. Phase 3. LiDAR Volume data were collected via the LiDAR platform and field-validated in four experiments. Expt.1: single-row plots of cultivars and experimental diploid breeding populations were scanned in the southern hemisphere spring for biomass estimation. Significant (P < 0.001) correlations were observed between LiDAR Volume and both fresh and dry weight data from 360 individual plots (R2 = 0.89 and 0.86 respectively). Expt 2: recurrent scanning of single row plots over long time intervals of a few weeks was conducted, and growth was estimated over an 83 day period. Expt 3: recurrent scanning of single-row plots over nine short time intervals of 2 to 5 days was conducted, and growth rate was observed over a 26 day period. Expt 4: recurrent scanning of paired-row plots over an annual cycle of repeated growth and defoliation was conducted, showing an overall mean correlation of LiDAR Volume and fresh weight of R2 = 0.79 for 1008 observations made across seven different harvests between March and December 2018.ConclusionsHere we report development and validation of LiDAR-based volumetric estimation as an efficient and effective tool for measuring fresh weight, dry weight and growth rate in single and paired-row plots of perennial ryegrass for the first time, with a consistently high level of accuracy. This development offers precise, non-destructive and cost-effective estimation of these economic traits in the field for ryegrass and potentially other pasture grasses in the future, based on the platform and algorithm developed for ryegrass.

LEAF PERFORMANCES OF CASSAVA GENOTYPES IN DIFFERENT SEASONS AND ITS RELATIONSHIP WITH BIOMASS

Information on leaf performances in different growing seasons of cassava could help achieve the recommendation regarding suitable cassava genotypes for particular planting date and a new plant type to improve cassava productivity. The objective of this study was to investigate leaf growth habit and biomass of the four cassava genotypes grown under irrigated condition in different growing seasons. The four cassava genotypes, i.e., Kasetsart 50, Rayong 9, Rayong 11 and CMR38-125-77 were grown at 30 June 2015 and 20 May 2016 and 3 November 2016 at Khon Kaen University, Thailand. A Randomised Complete Block Design (RCBD) with four replications was used for each planting date. Data recorded were leaf life, fallen leaf ratio, leaf area index (LAI), leaf area duration (LAD), storage root dry weight, total crop dry weight, harvest index (HI) and daily weather data. The results indicated that greater values of leaf life during 180 days after planting (DAP), LAD during 180-270 DAP, and LAI at 270 DAP appeared to associate with higher temperature. A combination of LAI at 180 DAP, leaf life during 90 and 180 DAP and fallen leaf ratio for 90 and 180 DAP was related to total biomass, while storage root dry weight was associated with a combination of LAI at 180 and 270 DAP and fallen leaf ratio for 90 and 180 DAP. CMR38-125-77 produced high total biomass and storage root dry weight at 270 DAP with possessing high LAI at 180 DAP.

Soil Type and Phosphorus Fertilization Affect Poa annua Growth and Seedhead Production

Core Ideas Excessive P fertilization produced larger Poa annua plants. Excess P fertilization created Poa annua plants that flowered earlier. Limiting P fertilization will help to create smaller Poa annua plants. Annual bluegrass (Poa annua L.) is a winter annual weed in southern landscapes. Previous research indicated that soil P or pH affects growth of annual bluegrass, which could provide tools for integrated control of a plant considered a weed in some turfgrass systems. The objective of this work was to evaluate the effects of P rate and soil type on growth parameters of annual bluegrass. This greenhouse study evaluated rates of P (0, 25, 50, 99, and 197 kg P ha−1) on 3 soil types (silty clay loam, loamy sand, and sand/peat [90:10% v/v] greensmix). Plant height, days to first seedhead (panicle), branches per panicle, seeds per branch, seed number and weight, and shoot and root dry weight data were collected by hand sampling and counting. Annual bluegrass seed was affected by both soil type and rate of P fertilization. Annual bluegrass plants grown in greensmix that received lower or zero P were 25% smaller than fertilized, took a week longer to produce a visible seed head, and had seed of reduced weight. Number of panicles, branches per panicle, seeds per panicle, and seeds per panicle branch were all unaffected by P rate, but often by soil type, where there were fewer of all when grown in greensmix. Avoidance of excessive P fertilization and subsequent accumulation of soil P may be an additional tool for the management and reduction of annual bluegrass.

Development of an Apparatus for Crop-Growth Monitoring and Diagnosis.

To non-destructively acquire leaf nitrogen content (LNC), leaf nitrogen accumulation (LNA), leaf area index (LAI), and leaf dry weight (LDW) data at high speed and low cost, a portable apparatus for crop-growth monitoring and diagnosis (CGMD) was developed according to the spectral monitoring mechanisms of crop growth. According to the canopy characteristics of crops and actual requirements of field operation environments, splitting light beams by using an optical filter and proper structural parameters were determined for the sensors. Meanwhile, an integral-type weak optoelectronic signal processing circuit was designed, which changed the gain of the system and guaranteed the high resolution of the apparatus by automatically adjusting the integration period based on the irradiance received from ambient light. In addition, a coupling processor system for a sensor information and growth model based on the microcontroller chip was developed. Field experiments showed that normalised vegetation index (NDVI) measured separately through the CGMD apparatus and the ASD spectrometer showed a good linear correlation. For measurements of canopy reflectance spectra of rice and wheat, their linear determination coefficients (R2) were 0.95 and 0.92, respectively while the root mean square errors (RMSEs) were 0.02 and 0.03, respectively. NDVI value measured by using the CGMD apparatus and growth indices of rice and wheat exhibited a linear relationship. For the monitoring models for LNC, LNA, LAI, and LDW of rice based on linear fitting of NDVI, R2 were 0.64, 0.67, 0.63 and 0.70, and RMSEs were 0.31, 2.29, 1.15 and 0.05, respectively. In addition, R2 of the models for monitoring LNC, LNA, LAI, and LDW of wheat on the basis of linear fitting of NDVI were 0.82, 0.71, 0.72 and 0.70, and RMSEs were 0.26, 2.30, 1.43, and 0.05, respectively.

Chlorophyll fluorescence and biomass of four cassava genotypes grown under rain‐fed upper paddy field conditions in the tropics

AbstractExpanding the area under cultivation and increasing the productivity are two solutions to fulfil the high cassava demand. The objective was to determine the quantum efficiency of photochemistry, relative water content (RWC), growth and biomass of four cassava genotypes grown under rain‐fed upper paddy field conditions. The four cassava genotypes (Kasetsart 50, Rayong 9, Rayong 11 and CMR38–125–77) were evaluated under three environments in rain‐fed upper paddy field conditions in the Khon Kaen province, Thailand, between 2015 and 2017. The experiment used a randomized complete block design (RCBD) with four replications. Data recorded were soil characteristics prior to planting, soil moisture, leaf RWC, chlorophyll fluorescence under natural light () and artificial dark (Fv/Fm) conditions, total dry weight (TDW), storage root dry weight (SRDW), starch yield and weather data during crop duration. The results from combined analysis indicated that the growing environment had a greater effect than genotypes for RWC (except for RWC at 90 days after planting (DAP), , Fv/Fm, TDW (except for TDW at 150 DAP), SRDW (except for SRDW at 150 DAP) and starch yield. There were significant interactions between genotypes and environments for TDW, SRDW and starch yield. CMR38–125–77 was the superior genotype for growing under rain‐fed upper paddy field conditions when compared to the other three cassava genotypes. This study also showed the possibility of using and Fv/Fm as criteria to improve the efficiency for cassava varietal selection.

Comparison of two ontogenetic growth equations for animals and plants

Ontogenetic growth reflects the changes of biomass, height (or body length) of a biological organism as a function of time. Many growth equations have been built but few can accurately predict the ending time of growth. Here we are attempting to provide two growth equations for predicting the time when growth terminates. Meanwhile, these models are also expected to apply to different growth patterns of biological organisms. Two time-dependent growth equations with four parameters each were obtained by replacing temperature with time in two non-linear mathematical models that describe the temperature-dependent developmental and growth rates of poikilotherms. Both models can generate a skewed or symmetrical bell-shaped curve. We obtained the growth equations by integrating these two temperature-dependent developmental rate models with temperature replaced by time. The dry weight data of six species of agricultural crops, the height data of four bamboo species, the tree-ring width data of two coniferous species, and the fresh weight data of 16 animals were used to fit these growth equations. Both growth equations agree well with the actual growth data of animals and plants. Additionally, one equation exhibits wide applicability and is better than the other in describing the tree-ring width. The time of reaching the maximal biomass or height can be predicted by these two models. The growth equations are valuable for predicting the time when the maximal biomass and height (or body length) are reached. Parameters of theses equations can directly reflect the growth rate: the conceptual starting time of growth, the ending time of growth, the maximal growth, and the time associated with the maximal growth rate that is actually the inflection point of the growth equation. We show that these two equations apply to many diverse species. It is worthwhile to explore and compare the growth patterns of biological organisms. In addition, the prediction of tree-ring width of conifers will be helpful to accurately predict the carbon storage in forest ecosystems.

Risk Assessment and Implications of Common Crupina Rust Disease for Biological Control

AbstractEvaluation ofPuccinia crupinae, the causal agent of a rust disease on common crupina (Crupina vulgaris), for biological control is described. Susceptibility of accessions of common crupina that represent both varieties of the target from the five populations in the United States indicate that the disease has potential to control common crupina, but differences were noted between accessions on the basis of pustule count, yield (i.e., number and weight of achenes per plant), and shoot dry weight data after multiple inoculations. One accession from Modoc, CA, was not affected in greenhouse tests and would likely not be affected in the field if a permit to releaseP. crupinaewere granted. None of the nontarget species of 26 taxa from the tribes Cardueae and Cichoriae were symptomatic, so the pathogen is likely safe to use in North America.

Genetics and Inheritance of Nontarget-Site Resistances to Atrazine and Mesotrione in a Waterhemp (Amaranthus tuberculatus) Population from Illinois

A waterhemp population (McLean County resistant, MCR) from McLean County, Illinois is resistant to both mesotrione and atrazine by elevated rates of herbicide metabolism. Research was conducted to investigate the inheritance of these resistance traits. Resistant and sensitive plants were crossed to obtain reciprocal F1populations, which were then used to create pseudo-F2and backcross (to sensitive parent; BCS) populations. The various populations were evaluated with whole-plant herbicide efficacy studies in a greenhouse. The responses of the F1populations to both mesotrione and atrazine were intermediate when compared with parental populations. In the case of atrazine, BCSand F2populations segregated 1 : 1 and 1 : 3, respectively, for susceptibility (S) : resistance (R), at a dose that controlled the sensitive parent but not the F1or resistant parent. For mesotrione, variability was observed within the F1populations, suggesting that mesotrione resistance is multigenic and the resistant parents used in the cross were not homozygous at the resistance loci. Furthermore, at low mesotrione doses, more F2plants survived than expected on the basis of a single-gene trait, whereas at high doses, fewer F2plants survived than expected. Dry weight data confirmed the conclusions obtained from survival data. Specifically, atrazine responses segregated into two discrete classes (R and S) in both the F2and BCSpopulations, whereas mesotrione responses showed continuous distributions of phenotypes in F2and BCSpopulations. We conclude that metabolism-based atrazine resistance in MCR is conferred by a single major gene, whereas inheritance of mesotrione resistance in this population is complex.

Additive biomass equations based on complete weighing of sample trees for open eucalypt forest species in south-eastern Australia

The aboveground biomass and carbon stock of less commercialized Eucalyptus open forests of south-eastern Australia are not well-known due to a lack of accurate biomass equations for even the prevalent species in these forests. To improve biomass and carbon estimates of these forests, a total of 245 trees of 11 eucalypt species with DBH (diameter overbark at the breast height of 1.3m above ground level) up to 139cm and height up to 39m were destructively sampled across three broad study sites in north-central Victoria. Trees were sampled as the four aboveground components of lower stem, upper stem, crown, and dead attached stem and branch materials. All four components were weighed completely in the field. To determine the dry to fresh weight ratio for each of the four components, 90 of these trees were further subsampled for moisture content. General linear models were used to relate dry to fresh weight ratio to site, species and tree size and the parameters of the models were estimated through generalized estimating equations. The model-estimated dry to fresh weight ratios were used to convert fresh weight to dry weight for all biomass components of fresh weight sample trees. Using the derived dry weight data, two systems of nonlinear additive biomass equations for stem, crown and total tree biomass were developed for each of the 11 species, with DBH as the independent variable in one system and the combined variable of DBH and tree height in another. Residual error variances and approximate confidence bands containing about 90% of the observed data about the mean curve of predicted biomass were estimated and derived for all biomass components of each species. In addition to the species-specific equations, two sets of site-specific biomass equations were developed using pooled biomass data from each site regardless of species. These systems of additive biomass equations will improve the accuracy of biomass and carbon estimation of open eucalypt forests in south-eastern Australia.

Enhanced production of a lutein-rich acidic environment microalga

This study was aimed at increasing productivity of a novel lutein-rich acidic environment microalga, Coccomyxa onubensis, based on efficient inorganic carbon use. Productivity was determined based on dry weight data; inorganic carbon concentration mechanisms were determined by means of carbonic anhydrase activity; carotenoids were extracted with methanol and measured by HPLC techniques. The existence of carbon concentration mechanisms and conditions that might lead to use them for addressing increased productivity of C. onubensis was studied. Best growth and carbon uptake capacity occurred at acidic pH, proving acid-tolerant behaviour of C. onubensis. Incubation in air followed by shift to high carbon conditions enhanced carbon-use efficiency in terms of growth rate and biomass productivity, based on the action of both carbonic anhydrase activities. Lutein accumulated in the microalga at high concentrations above 5-6 g kg(-1) dry weight and did not depend on inorganic carbon conditions. Consequently, repeated cycles of air incubation and high CO2 incubation of C. onubensis might become a suitable tool to perform production processes of lutein-enriched biomass. This study intends to show that acidic environment microalgae can be produced at similar productivities of nonextreme microalgae, with the added advantage of their growth in highly selective culture medium. Particularly, it is applied to C. onubensis which accumulates lutein at commercially relevant concentrations.

Long-term degradation of poly-lactide co-glycolide/B-tricalcium phosphate biocomposite anchors in arthroscopic repair of Bankart's lesions. A prospective study

Twenty-day-old striped bass (Morone saxatilis) larvae were exposed to a range of treated bleached kraft mill effluent (BKME) concentrations from 0 to 20% effluent by volume (v/v) under continuous flow test conditins. The experimental test concentrations in the 2–20% BKME test aquaria had a BOD5 which ranged from < 1 to 5 mg l−1, TSS 12–17 mg l−1, and true color 35–416 mg l−1. Bleached kraft mill effluent did not kill larvae exposed to it for 20 days through metamorphosis to the juvenile stage. The BKME did not alter growth in length, weight or condition factor in larvae over the 20-day exposure period as determined by multiple regression analysis. A linear regression analysis on the dry weight data at Day 20 only, however, indicated a trend of decreasing weight with increasing BKME concentration. Effluent-exposed larvae also developed normally during the 20-day study. All individuals examined completed the transformation from postlarvae to juveniles by the age of 40 days.