Analysis of chemical changes in Picea abies wood decayed by different Streptomyces strains showing evidence for biopulping procedures

The present study is focused on analysing the suitability of different Streptomyces strains for biomechanical pulping purposes using spruce wood (Picea abies) as substrate. After 2 weeks of incubation, no apparent variations in lignin Klason content of treated woods were detected compared with the control. However, the increase in acid-soluble lignin fraction pointed out chemical alterations in lignin moiety. Through Py-GC/MS analysis enrichment in cellulose and lignin molecule modifications were detected in treated woods. The increase in the relative abundance of the most G-type phenol units with a higher oxidation degree suggests that some oxidation occurred in the lignin C3-alkyl chain. In addition, the decrease in the phenylmethane + phenylethane/phenylpropane (phC1 + ph C2/ph C3) ratio would indicate the ability of Streptomyces strains to breakdown the C3-alkyl chain linkages once carbons had been oxidized. From this study it could be concluded that the assayed strains are able to produce a delignification of spruce wood which may improve mechanical pulping processes.     

Biomass production potential of three short rotation woody crop species under varying nitrogen and water availability

A study was conducted in an agricultural field to examine the biomass production of three fast-growing short rotation woody crop (SRWC) species, Populus deltoides, Quercus pagoda, and Platanus occidentalis using fertilization and irrigation (fertigation). The study included a randomized complete block (RCB) with five treatments; control, irrigated, and irrigated with 56, 112, and 224 kg nitrogen (N) ha⁻¹ year⁻¹. We quantified survival, basal area, standing biomass, aboveground net primary productivity (ANPP), leaf area index (LAI), and growth efficiency (GE) for each species along the soil nitrogen and water gradient. P. deltoides had low rates of survival (83, 82, and 77% years six, seven, and eight, respectively), but had production values greater than Q. pagoda and P. occidentalis. Standing biomass reached its peak for P. deltoides and P. occidentalis (17.56 and 10.36 Mg ha¹, respectively) in the irrigation treatment, and in the 112 kg N treatment for Q. pagoda (5.42 Mg ha⁻¹). P. deltoides and P. occidentalis ANPP peaked in the irrigation treatment (6.66 and 6.31 Mg ha⁻¹ year⁻¹, respectively) and in the 112 kg N (4.43 Mg ha⁻¹ year⁻¹) for Q. pagoda. ANPP was correlated with LAI; however, the relationship was species specific. Maximum ANPP was reached below the maximum LAI for Q. pagoda and P. occidentalis. P. deltoides ANPP was highest at the maximum LAI, which was achieved with IRR. These results suggest that species-specific cultural practices producing optimum LAI and maximum ANPP should be identified before fertigation techniques are adopted widely for SRWC production on agricultural fields.     

Spatial sap flow and xylem anatomical characteristics in olive trees under different irrigation regimes

The compensation heat pulse (CHP) method is widely used to estimate sap flow and transpiration in conducting organs of woody plants. Previous studies have reported a natural azimuthal variability in sap flow, which could have practical implications in locating the CHP probes and integrating their output. Sap flow of several olive trees (Olea europaea L. cv. 'Arbequina') previously grown under different irrigation treatments were monitored by the CHP method, and their xylem anatomical characteristics were analyzed from wood samples taken at the same location in which the probes were installed. A significant azimuthal variability in the sap flow was found in a well-irrigated olive tree monitored by eight CHP probes. The azimuthal variability was well related to crown architecture, but poorly to azimuthal differences in the xylem anatomical characteristics. Well-irrigated and deficit-irrigated olive trees showed similar xylem anatomical characteristics, but they differed in xylem growth and in the ratio of nocturnal-to-diurnal sap flow (N/D index). The results of this work indicate that transpiration cannot be accurately estimated by the CHP method in olive trees if a small number of sensors are employed and that the N/D index could be used as a sensitive water status indicator.     

The effect of tillage,crop rotation and residue management on maize and wheat growth and development evaluated with an optical sensor

Crop growth and development as well as yield are the result of the efficiency of the chosen agricultural management system within the boundaries of the agro-ecological environment. End-of-season yield results do not permit the evaluation of within-season management interactions with the production environment and do not allow for full understanding of the management practice applied. Crop growth and development were measured during the 2004, 2006 and 2008 crop cycles with an optical handheld NDVI sensor for all plots of the different management treatments of a long-term (since 1991) sustainability trial in the highlands of Mexico. Cropping systems varying in (1) tillage (conventional vs. zero tillage); (2) residue management (retention vs. removal); (3) rotation (monocropping vs. a maize [Zea mays L.]/wheat [Triticum aestivum L.] rotation) were compared. The NDVI-handheld sensor was evaluated as a tool to monitor crop growth and development and was found to be an excellent tool for this purpose. There was a strong relation between NDVI and biomass accumulation of maize and wheat. The measurement with the handheld sensor was non-destructive and fast so that a representative plot area could be measured easily and time-efficiently. Zero tillage induced different crop growth dynamics over time compared to conventional tillage. Zero tillage with residue retention is characterized by a slower initial crop growth, compensated for by an increased growth in the later stages, positively influencing final grain yield. Also crop rotation influenced early crop growth, with lower NDVI values for crops sown after wheat than crops after maize. Zero tillage with residue removal had low NDVI values throughout the growing season. Zero tillage with retention of crop residues results in time efficient use of resources, as opposed to conventional tillage, regardless of residue management, and zero tillage with residue removal. The results indicated that different tillage, rotation and residue management practices influence crop growth and development. It is important to monitor and understand crop growth under different management systems to select the right varieties and adjust timing and practice of input supply (fertilizer, irrigation etc.) in a holistic way in each cropping system.     

Buffel grass (Cenchrus ciliaria L.) substitution for orange pulp on intake, digestibility, and performance of hairsheep lambs

Twenty Dorper x Pelibuey male lambs were used to evaluate the effect of substitution of forage with fresh orange pulp (FOP) in diets for fattening lambs on productive behavior, nutrient intake, apparent digestibility coefficient, and feeding costs. Lambs were divided into five groups (n?=?4) and then housed in individual pens during 70 d. Treatments consisted of five levels of FOP (0, 25, 50, 75 and 100%) which substituted buffel grass hay on the base diet (40:60%, forage:concentrate). Additionally, changes in chemical composition of FOP stored in stack during 8 d were evaluated (from the day 1 until day 8). Daily feed intake expressed as kg/day and % live weight, lamb growth rate, feeding cost of each lamb per day and per fattening period, hemicellulose intake, and DM, OM, CP, NDF and hemicellulose digestibility showed a quadratic effect (P?<?0.05), while DM, OM and CP intake presented a cubic effect (P?<?0.05) with the increasing level of FOP. The maximum estimated value for those variables was observed at 75% of hay replacement with FOP. With respect to changes in chemical composition of pulp stored, DM content increased (P?=?0.0011) from 210 to 310 g/kg FOP and OM, fiber fraction, and ash content were constant (P?>?0.05) among storage days. Therefore, replacing around 75% of buffel grass hay with FOP in diets for fattening lambs resulted in the best growth rate and more efficient diet utilization. Fresh orange pulp stored in a stack did not change its chemical composition, and did not affect its utilization as a sheep feedstuff.     

Experimental infection with Mycobacterium caprae in goats and evaluation of immunological status in tuberculosis and paratuberculosis co-infected animals

Tuberculosis in goats (caused by Mycobacterium caprae and M. bovis) has become a significant concern in recent years because of its high prevalence in certain caprine herds in Spain and other European countries, and also due to the potential transmission to other animals and human beings. In the present study, a transthoracic model of tuberculosis infection was performed on goats. Animals were selected based on the serological response used to detect paratuberculosis in goats (negative and positive results). The kinetics of the immune response was evaluated using the interferon-γ (IFN-γ) assay, skin tests and serology of paratuberculosis during nine months post-challenge. At the end of the study the animals were necropsied, tuberculosis-lesions were scored and culture (M. caprae and M. avium subsp. paratuberculosis) was performed to determine the true infection status. Animals were positive to the IFN-γ assay 15 days post-challenge and the values were fluctuating throughout the study. A varied performance of the assay was observed between tuberculosis and tuberculosis-paratuberculosis mixed infection regarding both the number of positive results and the OD values obtained after stimulation with bovine and avian PPDs. Furthermore, the single intradermal comparative cervical tuberculin test did not detect all M. caprae-infected animals. At necropsy, a positive correlation between pathology score and bovine PPD specific IFN-γ response was found.     

Ecological consequences of an exotic fungal disease in eastern U.S. hardwood forests

Exotic pests and pathogens can cause extensive mortality of native species resulting in cascading effects within an ecosystem. As ecosystems lose species to exotic enemies, ecosystem function may be disrupted if the ecological roles are not filled by the remaining species. To illustrate this concept, this paper examines the impacts of an exotic fungus (Discula dectructiva) on flowering dogwood (Cornus florida), historically a common understory tree species in eastern U.S. hardwood forests. Recent studies indicate that dogwood plays an important role in the health and ecological integrity of forest ecosystems throughout the eastern U.S. by increasing the availability of calcium in the biota-rich surface horizons of forest soils. However, Discula destructiva causes a disease, dogwood anthracnose, which can rapidly kill dogwood trees. This paper also illustrates how past fire has increased dogwood density and improved tree health in areas infected with anthracnose, suggesting that prescribed fire may offer a tool for land managers to maintain dogwood as a component in eastern U.S. hardwood forests by shifting the “ideal” disturbance regime of this previously fire-intolerant species.     

The Brazil Eucalyptus Potential Productivity Project: Influence of water,nutrients and stand uniformity on wood production

We examined the potential growth of clonal Eucalyptus plantations at eight locations across a 1000+ km gradient in Brazil by manipulating the supplies of nutrients and water, and altering the uniformity of tree sizes within plots. With no fertilization or irrigation, mean annual increments of stem wood were about 28% lower (16.2 Mg ha⁻¹ yr⁻¹, about 33 m³ ha⁻¹ yr⁻¹) than yields achieved with current operational rates of fertilization (22.6 Mg ha⁻¹ yr⁻¹, about 46 m³ ha⁻¹ yr⁻¹). Fertilization beyond current operational rates did not increase growth, whereas irrigation raised growth by about 30% (to 30.6 Mg ha⁻¹ yr⁻¹, about 62 m³ ha⁻¹ yr⁻¹). The potential biological productivity (current annual increment) of the plantations was about one-third greater than these values, if based only on the period after achieving full canopies. The biological potential productivity was even greater if based only on the full-canopy period during the wet season, indicating that the maximum biological productivity across the sites (with irrigation, during the wet season) would be about 42 Mg ha⁻¹ yr⁻¹ (83 m³ ha⁻¹ yr⁻¹). Stands with uniform structure (trees in plots planted in a single day) showed 13% greater growth than stands with higher heterogeneity of tree sizes (owing to a staggered planting time of up to 80 days). Higher water supply increased growth and also delayed by about 1 year the point where current annual increment and mean annual increment intersected, indicating opportunities for lengthening rotations for more productive treatments as well as the influence of year-to-year climate variations on optimal rotations periods. The growth response to treatments after canopy closure (mid-rotation) related well with full-rotation responses, offering an early opportunity for estimating whole-rotation yields. These results underscore the importance of resource supply, the efficiency of resource use, and stand uniformity in setting the bounds for productivity, and provide a baseline for evaluating the productivity achieved in operational plantations. The BEPP Project showed that water supply is the key resource determining levels of plantation productivity in Brazil. Future collaboration between scientists working on silviculture and genetics should lead to new insights on the mechanisms connecting water and growth, leading to improved matching of sites, clones, and silviculture.     

Hematology and Clinical Pathology Data in Chronically Starved Horses

Hematology and serum/plasma biochemistry are important diagnostic aids to assess metabolic status in starved horses and to rule out pathologic conditions that present as emaciation. This article reviews the interpretation of these parameters, using 10 chronically starved horses as examples. The study was conducted on these 10 neglected horses belonging to both sexes, aged between 4 and 25 years. The animals were divided into two groups according to their body condition scoring (BCS): A (n = 6; BCS of 3 or lower) and B (n = 4; BCS higher than 3). A complete clinical examination was carried out, and venous blood samples were taken to perform hematological, biochemical, and serological determinations. The findings indicated that the most emaciated horses (group A) presented normocytic normochromic anemia, with higher numbers of both immature and mature neutrophils, monocytes, and eosinophils, and lower number of lymphocytes. Furthermore, horses in group A showed lower serum concentrations of urea, triglycerides, bile acids, alkaline phosphatase, and a lower urea/creatinine ratio. Both groups of horses presented with hypomagnesemia. In conclusion, the knowledge of the laboratorial findings in emaciated horses is useful in scoring the intensity of the emaciation, and in establishing a prognosis and a plan to recover the health status of these animals.     

Signaling pathways involved in liver injury and regeneration in rabbit hemorrhagic disease, an animal model of virally-induced fulminant hepatic failure

Management of fulminant hepatic failure (FHF) continues to be one challenging problem, and experimental animal models resembling its clinical conditions are still needed. Rabbit hemorrhagic disease (RHD) fullfils many requirements of an animal model of FHF. This work investigated changes in MAPK, NF-κB, AP-1 and STAT pathways during RHD-induced liver injury. Rabbits were infected with 2 × 10⁴ hemagglutination units of an RHD virus isolate. Apoptosis was documented by the presence of caspase-3 activity and substantial PARP proteolysis at 36 and 48 h postinfection (pi). Infection induced a marked and maintained expression of TNF-α from 12 h pi, while there was only a transitory increase in IL-6 expression. Expression of phosphorylated (p)-JNK, p-p38 and p-ERK1/2 was significantly elevated at 12 h pi. At 48 h pi p-JNK expression was maintained at a maximum level, while that of p-p38 returned to normality and there was no p-ERK1/2 expression. Activation of NF-κB and AP-1 and increased expression of VCAM-1 and COX-2 were observed. No significant changes were detected in activation of STAT1 and STAT3, while SOCS3 expression increased significantly. The current findings suggest that activation of JNK is an essential component in liver injury mediated by the RHD virus and that lack of activation of STAT3, probably mediated by SOCS3 over-expression, would contribute to the inhibition of the regenerative response. Data show the presence of molecular mechanisms contributing to liver damage and the lack of regeneration and they support the usefulness of this model to investigate novel therapeutical modalities in FHF.