Regrowth Period Research Articles

TU‐G‐BRA‐09: MR Elastography as a Predictor of Therapeutic Response: Assessment in Non‐Hodgkin's Lymphoma (NHL)

Purpose:To develop magnetic resonance elastography (MRE) as a noninvasive imaging biomarker of treatment response in cancer and to evaluate its prognostic potential for assessing chemotherapy response in non‐Hodgkin's lymphoma (NHL).Methods:A small animal cancer MRE methodology was developed which included a custom‐built 4 cm, 8‐channel receive‐only coil and an electromechanical driver capable of producing shear waves at a frequency of 800 Hz attached to an MRI‐compatible needle inserted in tissue. MRE reproducibility was evaluated in tumor phantoms and in vivo mouse experiments. Tumor shear stiffness was monitored following a single chemotherapy treatment in a murine xenograft of NHL to determine the biomechanical effect of an initial therapy response followed by tumor regrowth. The effect of an increased chemotherapy dose on the resulting decrease in tumor shear stiffness was quantified. In vivo evaluation of the feasibility of this potential biomarker was performed on three patients with NHL prior to and 2 weeks after chemotherapy treatment.Results:Tumor phantom models and in vivo measurements demonstrated excellent shear stiffness reproducibility with a standard deviation of ±3%. In the murine model, tumor shear stiffness and volume changes following chemotherapy treatment corresponded to periods of response and subsequent tumor regrowth. Shear stiffness alterations demonstrated a dose dependency with a decrease of 15% and 25% for the low and high dose group respectively compared to an increase of 7% in an untreated control group. In three patients with NHL, tumor shear stiffness decreased by an average of 38% within 2 weeks of chemotherapy treatment.Conclusion:These data demonstrate that MRE is a potentially sensitive biomarker of disease stage and response to therapy in cancer. The results demonstrate that MRE‐derived shear stiffness measurements are sensitive to chemotherapy response and disease progression in vivo, and are the first human application of MRE as a noninvasive assessment of therapy response.Funding provided by the Mayo Clinic Center for Individualized Medicine, Imaging Biomarker Discovery Program and the Mayo Graduate School.

Effect of nitrogen fertilization rate and regrowth interval of grass herbage on methane emission of zero-grazing lactating dairy cows

Dairy cattle farming in temperate regions often relies on grass herbage (GH)-based diets but the effect of several grass management options on enteric CH4 emission has not been fully investigated yet. We investigated the combined effect of N fertilization rate and length of regrowth period of GH (predominantly ryegrass) on CH4 emission from lactating dairy cows. In a randomized block design, 28 lactating Holstein-Friesian dairy cows received a basal diet of GH and compound feed [85:15; dry matter (DM) basis]. Treatments consisted of GH cut after 3 or 5 weeks of regrowth, after receiving either a low (20kg of N/ha) or a high (90kg of N/ha) fertilization rate after initial cut. Feed intake, digestibility, milk production and composition, N and energy balance, and CH4 emission were measured during a 5-d period in climate respiration chambers after an adaptation to the diet for 12d. Cows were restricted-fed during measurements and mean DM intake was 15.0±0.16kg/d. Herbage crude protein content varied between 76 and 161g/kg of DM, and sugar content between 186 and 303g/kg of DM. Fat- and protein-corrected milk (FPCM) and feed digestibility increased with increased N fertilization rates and a shorter regrowth interval. Increasing the N fertilization rate increased daily CH4 emission per cow (+10%) and per unit of DM intake (+9%), tended to increase the fraction of gross energy intake emitted as CH4 (+7%), and (partly because of the low crude protein content for the low fertilized GH) only numerically reduced CH4 per unit of FPCM. The longer regrowth interval increased CH4 emission per unit of FPCM (+14%) compared with the shorter regrowth interval, but did not affect CH4 emission expressed in any other unit. With increasing N fertilization CH4 emission decreased per unit of digestible neutral detergent fiber intake (−13%) but not per unit of digestible organic matter intake. There was no interaction of the effect of N fertilization rate and regrowth interval on CH4 emission, but effects of N fertilization were generally most distinct with GH of 5 wk regrowth. The present results suggest that altering grass quality through an increase of N fertilization and a shorter regrowth interval can reduce CH4 emission in zero-grazing dairy cows, depending on the unit in which it is expressed. The larger amount of CH4 produced per day and cow with the more intensively managed GH is compensated by a higher feed digestibility and FPCM yield.

Water Deficit and Nitrogen Fertilizer Effects on NDVI of �Tifton 85� Bermudagrassduring Regrowth

<abstract> <bold><sc>Abstract. </sc></bold>A better understanding of how bermudagrass (Cynodon spp.) regrowth is influenced by production inputs will aid in advancing precision management. The objectives were to evaluate the effect of irrigation and nitrogen (N) on normalized difference vegetative index (NDVI) during regrowth and evaluate the relationship between NDVI during regrowth to forage yield. Normalized difference vegetative index (NDVI) data were collected in an experiment evaluating two harvest schedules (four or eight week), four rates of irrigation (0, 4.2, 8.4, or 12.5 mm of water each irrigation event), and three rates of N (season total of 168, 336, and 504 kg N ha^-1). Both irrigation and N influenced NDVI of bermudagrass during the regrowth periods of both the four- and eight-week harvest schedules, but there were no irrigation by N interactions. As was expected, regrowth (as measured by NDVI) in response to irrigation was dependent on the timing and duration of rain-free periods within the regrowth periods. Generally, NDVI increased with increasing N rate at most sampling dates. Regression slopes of yield versus NDVI measured near the end of the regrowth period were higher for the eight-week harvest schedule than for the four-week schedule. Within each harvest schedule, however; slopes were similar. The high correlation coefficients between NDVI late in the regrowth period and yield suggest NDVI is a useful tool for managing bermudagrass harvests.

The effects of environment temperature and moisture to investigate seeds germination of jimsonweed

To investigate the variation of the germination in Datura in the soil after the seed spreading, a factorial experiment based on a randomized complete block design was conducted in three replications, in 2011-2012 in Karaj, Iran. The first factor was three moisture regimes (dryness treatment, H1; alternate wetting and dryness, H2; wetting, H3) and the second factor was temperature in four levels, representing the temperature of various months (integrated the December and January, T1; February and March, T2; April, T3; and at the end of May and June, T4) were simulated on data seeds population from spreading time to re-growth period. All treatments were applied during 30 days and then the germination test was done in 8-35°C. Thereafter, according to the estimated parameters, the relationship between temperature and moisture was investigated with germination models. Results indicated that an estimate of the sigmoidal function parameters with three parameters could be a demonstrator for germination patterns. The results of the functions showed that a gradual increase in environmental temperature caused an increase in germination coefficient when the seed were completely dried. However, this increase was negligible in comparison with the increase that observed in response to other treatments (H2-H3).In all moisture levels, the seeds of Datura did not have a suitable germination in 4 and 7°C, but the rate of germination was increased when the temperature was increased up to 15 and 23°C, especially for alternate wetting and drying conditions.

Pasture yield mapping: why &amp; how

Spatial variation in pasture yield within a single paddock can be high. Measuring this variation has many potential benefits. For instance, cost-effective targeted treatments could be applied to low yielding areas resulting in increased pasture yield at a paddock scale with minimal cost. Understanding pasture yield variation requires tools that can measure it, and practical methodologies to guide how and when to use these tools to obtain useful data. The study reported here aimed to develop measurement protocols for using the C-Dax pasture meter to map yields of rotationally grazed pastures. The general principles should be applicable to other measurement tools. The pattern of pasture yield varies throughout the year. Because growing conditions change with the seasons, areas of a paddock that perform well in summer may perform poorly in winter, and vice-versa. Time of year is therefore an important consideration for measurement purposes. The recommended protocol developed from this project to estimate the spatial variation in annual yield on a paddock is to: • map 1 month following peak pasture growth rates; • drive at up to 50 m run spacings, but close enough to cover all features of interest; and • map as close to the grazing event as possible within the final third of the regrowth period. Keywords: Yield mapping, pasture, precision agriculture, pasture height, dairy, spatial management

Modeling the impact of net primary production dynamics on post-disturbance Amazon savannization

Amazon tropical forests are being replaced by pasturelands and croplands, but they sometimes revert to regrowth forest when abandoned after a period of agricultural use. Research suggests that this secondary regrowth is limited by climate and nutrient availability and, using a coupled biosphere-atmosphere model, we investigated patterns in the regrowth of the Amazon rainforest after a full deforestation event, considering different types of nutrient stress. We found that, over a 50 year regrowth period, the reduction of precipitation caused by large-scale deforestation was not sufficient to prevent secondary forest regrowth, but this decrease in precipitation combined with nutrient limitation, due to logging and frequent fires, did indeed prevent forest regrowth in central and southern Amazonia, leading to a savannization. These results are concerning, as the northern Mato Grosso region has the highest clearing rate in Amazonia. The low resilience of the forest under nutrient stress indicates that a large scale disturbance could greatly expand the area suitable for cropland, accelerating forest disappearance.

Intake rate and nutritive value of elephant grass cv. Napier subjected to strategies of rotational stocking management

Several research papers on tropical forage grasses have demonstrated that grazing management modifies sward structure that, in turn, alters patterns of ingestive and foraging behavior of the grazing animal. For that reason it has been used to explain adjustments in intake characteristics like bite mass, bite rate, intake rate and nutritive value of the consumed herbage (Fonseca et al. 2012). Tall tussock plants like elephant grass (Pennisetum purpureum) cv. Napier display stem elongation during the vegetative state (da Silva and Carvalho 2005), causing swards to become too tall and out of reach for grazing animals, making efficient grazing management difficult, particularly when long regrowth periods are used. In that context, an increase in defoliation frequency can improve herbage intake and nutritive value (Palhano et al. 2007), by favoring leaf elongation as opposed to stem elongation and senescent material accumulation throughout successive grazing cycles. Against that background, the objective of this experiment was to evaluate the components of short-term herbage intake (intake rate, bite mass and bite rate) and nutritive value of the consumed herbage from elephant grass cv. Napier subjected to rotational stocking management defined in terms of preand post-grazing management targets.

Temporal variation in organic matter supply in kelp forests: linking structure to trophic functioning

Owing to their productivity, kelps may be the main primary carbon source for consumers in coastal areas. Their contribution has often been compared to that of phytoplankton, but the potential involvement of the red algae associated with kelp forests has been overlooked. All these 3 primary sources have distinct life cycles and may contribute to the particulate organic matter pool differently according to season. In the present study, we characterised the trophic structure of a pristine Laminaria hyperborea forest off the coast of Brittany (France) in terms of the organic carbon biomass of the main primary producers and consumer trophic groups on 4 sampling dates over a 1 yr period. Senescence of many red algae species occurred during their resting period (i.e. before November), whereas the kelp regrowth period (i.e. before March) was accompanied by the fragmentation of old lamina. During these periods, when phytoplankton biomass is comparable, stable isotope analyses (delta C-13 and delta N-15) were conducted in an attempt to link structure to trophic functioning. By combining analyses of temporal variability in primary source and consumer isotopic ratios and using mixing models, we inferred changes in the trophic significance of macroalgae in the associated food web. Decaying kelp laminae were a major contributor to the particulate organic matter pool, and the fragmentation of old lamina promoted their contribution to the diet of deposit-and suspension-feeders in March. Growth of red algae enhanced direct grazer consumption in March, while their senescence contributed significantly to primary consumer diets in November via indirect consumption.

Mapping forest growth and decline in a temperate mixed forest using temporal trend analysis of Landsat imagery, 1987–2010

Forest management seeks sustainability for a diverse set of goals, including economic objectives, provision of ecosystem services, and provision of a variety of possible land uses. It is important to quantify, map and monitor forest dynamics resulting from natural and anthropogenic processes over time periods appropriate to the temporal scale of change as well as to land management goals and decision making. This paper presents temporal trend analyses of temperate mixed forest dynamics in Gatineau Park, Québec, Canada, using a time series of Landsat 5 TM scenes. Several vegetation indices were first evaluated as indicators of field measured vegetation abundance parameters such as leaf area index, canopy openness, DBH, and basal area. Of these, Tasseled Cap Wetness (TCW) provided the best relationships (e.g., r=0.81 against LAI) and it differentiated between coniferous, mixed and deciduous forests. Thirteen clear sky 5 TM scenes from the growing seasons of 1987 to 2010 were relatively calibrated and assembled into an image time-series. TCW applied to the image time-series followed by Theil–Sen and Contextual Mann–Kendall trend analysis detected subtle and gradual field-verified forest change. Gradual and abrupt forest decline or regrowth periods were identified; over the full period, 641ha (1.8% of the park) exhibited statistically significant growth, and 689ha (1.9%) exhibited decline. Mapping the timing, location, magnitude, and duration of forest change will help inform land management policy and actions within Gatineau Park and such methods may be applied in other similar forests.

The case study of an Italian contemporary art object: Materials and state of conservation of the painting “Ragazzo seduto” by Remo Brindisi

Abstract This paper deals with the scientific survey of Remo Brindisi's painting “Ragazzo seduto” (Seated boy), made at the end of the 1950s, that is a symbolic figure of both his personal artistic solitude and the crisis of values determined by the economic boom in the post-war period. In a period of great changes and economic regrowth, the need to find a new style that could be the most authentic and personal as possible pressed the artist to experiment innovative products, including non-conventional support. Photographic and analytical techniques demonstrated the use of innovative products as an experimentation tendency, that pressed the artist to use non-conventional support, industrially treated with plasticized PVC and primed with acrylate polymers and to paint with traditional and industrial pigments mixed with an oil-modified alkyd resin. In the span of a few years, an unexpected and extended degradation on the whole surface of the painting took place, with the consequent formation of lifting and detachment of the paint film. The detected alteration is mainly due to the fast ageing of the employed polymeric materials, actually responsible of the impermanence of many contemporary works of arts. Clarifying the unknown aspects of the Remo Brindisi's stylistic choices together with the deterioration processes of the employed painting materials, this paper highlights the general problems related to the conservation of contemporary art, a neglected area of research in Italy, where more efforts are committed to the enormous and more ancient cultural heritage.

Pasture degradation impacts soil phosphorus storage via changes to aggregate-associated soil organic matter in highly weathered tropical soils

Maintaining the productivity of tropical pastures is a major challenge for the sustainable management of tropical landscapes around the globe. To address this issue, we examined linkages between soil organic matter (SOM), aggregation, and phosphorus (P) dynamics by comparing productive vs. degraded pastures in the deforested Amazon Basin of Colombia. Paired plots of productive (dominated by planted Brachiaria spp.) vs. degraded pasture were identified on nine farms in the Department of Caquetá and sampled during the rainy season of 2011. Aboveground pasture biomass production and nutrient content were measured. Surface soils (0–10 cm) were also fractionated by wet sieving, and C, 13C, N and P contents were analyzed for the bulk soil and various aggregate size classes. Productive pastures yielded more than double the aboveground biomass compared to degraded pastures (during a 35 day regrowth period following cutting), with over 60% higher N and P contents in this material. Similar trends were observed for the standing litter biomass and nutrient contents. Soil aggregate stability was found to differ between pasture types, with a mean weight diameter of 3590 vs. 3230 μm in productive vs. degraded pastures, respectively. Productive pastures were found to have 20% higher total soil C and N contents than degraded pastures. While there was no difference in total P content between pasture types, organic P was found to be nearly 40% higher in soils of productive vs. degraded pastures. Differences in total SOM between pasture types were largely explained by a higher C content in the large macroaggregate fraction (>2000 μm), and more specifically in the microaggregates (53–250 μm) occluded within this fraction. These findings confirm the role of microaggregates within macroaggregates as a preferential site for the physical stabilization of SOM, and furthermore, suggest that it may serve as a useful diagnostic fraction for evaluating management impacts on SOM in tropical pasture systems. Similar to trends observed for C and N, total P content was 25% higher in the microaggregates within large macroaggregates of productive vs. degraded pasture soils. This correspondence between C and total P contents in large macroaggregate fractions, along with elevated levels of organic P in productive pastures, suggests that this P is likely in an organic form and that there is a close link between soil structure, SOM dynamics and the maintenance of organic P in these soils. Given the potential relevance of organic P for efficient P cycling in these soils, our findings offer critical new insight for the management of SOM and aggregate-associated P pools in tropical pasture systems.

Efficacy of straight versus angled interdental brushes on interproximal tooth cleaning: a randomized controlled trial

To investigate interproximal biofilm reduction with an angled interdental brush as compared to a straight interdental brush (standard control) in a clinical, single-centre, single-blind, controlled, parallel-group trial. Recruitment and examinations of the subjects were performed at the Witten/Herdecke University School of Dental Medicine. 128 volunteers, aged 20-65years, were recruited and stratified according to sex and age. Two groups with 64 subjects each used either straight (standard control) or angled (test group) handgripped interdental toothbrushes of the same bristle stiffness. After a 12-day home-care habituation period, participants received a professional tooth cleaning followed by a 48-h plaque regrowth period. At the intervention appointment, plaque was recorded with a fluorescent revelator and soft tissue damage was noted (T0 ). Interdental brushing was performed by the participant for 2min, and clinical parameters were recorded again (T1 ). The primary efficacy end point was the difference in modified Proximal Plaque Index (mPPI) after brushing compared to baseline. Secondary efficacy end points were mPPI differences in subgroups (anterior vs. posterior teeth; vestibular vs. oral tooth surfaces). Safety end point was the Danser gingival abrasion index (DI). mPPI showed lower scores after brushing within all (sub)groups (P<0.01). mPPI brushing efficacy (ΔT0 -T1 ) in subjects using straight interdental brushes was significantly higher as compared to angled interdental brushes (P<0.0001). Straight interdental brushes were significantly more effective in posterior teeth, when used from vestibular and from oral tooth surfaces (P<0.0001, P<0.01 and P<0.0001, respectively). No significant differences were found between the groups in anterior teeth and concerning soft tissue damage. Straight interdental brushes may better remove plaque interproximally when compared to angled interdental brushes.

The effects of three different mouth rinses in a 4-day supragingival plaque regrowth study.

Objective:This study compares the effects of three different mouth rinses with respect to reducing Streptococcus mutans (S. mutans) colony counts on the teeth and tongue surfaces.Materials and Methods:In this study, comparison tests using the alcohol-free 0.1% chlorhexidine mouth rinse, alcohol-containing essential oil mouth rinse, and alcohol-free essential oil-containing mouth rinse were conducted. Patients were instructed to avoid mechanical cleaning with either a toothbrush or toothpick for 4 days. The first samples were collected from teeth surfaces and the dorsum of the tongue after a professional cleaning, and the second samples were collected after a 4-day plaque re-growth period. The supragingival plaque from the buccal surfaces of teeth #11, 14, 31, 34 as well as samples from the dorsum of the tongue, were assessed using the Dentocult® strips.Results:The Listerine® and Ondrohexidine® groups did not show any statistically significant differences between the values of the two samples (P = 0.734, P = 0.307). The MC® group and the control group showed significantly higher results than the first sample values. The effectiveness of the mouth rinses on S. mutans colony counts from the teeth surfaces were higher in the Listerine®, Ondrohexidine®, and Mouthwash Concentrate® groups. The difference between the first and second samples of the S. mutans colony counts from the tongue surface was found to be statistically significant, and S. mutans colony counts were higher than the first sample (P = 0.015).Conclusion:Alcohol and essential oil-containing Listerine® mouth rinse, alcohol-free Ondrohexidine®, alcohol-free essential oil-containing MC® mouth rinse had the same effect on S. mutans counts, higher than the 1% alcohol solution on teeth surface. They had the ability to maintain the S. mutans counts at the same level for 4 days in patients who did not perform any mechanical oral hygiene regimen.

Nutritive value, in vitro fermentation and methane production of perennial pastures as affected by botanical composition over a growing season in the south of Chile

Permanent pastures have been shown to produce similar herbage masses and nutrient contents to perennial ryegrass pastures. To the best of our knowledge, little research has been conducted on the ruminal fermentation of permanent pastures. Our objective was to evaluate the effect of botanical composition of four perennial pastures during a growing season in the south of Chile [winter, September 2010 ‘S1’; spring, November 2010 ‘S2’; and summer, January 2011 ‘S3’]: on in vitro fermentation products using a batch culture system. The perennial pastures studied included: permanent (PP), permanent fertilised (PFP) and renovated pastures (Lolium perenne and Trifolium repens pasture ‘RGWC’; Bromus valdivianus, Dactylis glomerata, Holcus lanatus, L. perenne and T. repens ‘MIXED’). There were strong interactions between pasture type and regrowth period for true organic matter, nitrogen (N) and neutral detergent fibre digestibility; total gas and volatile fatty acid (VFA) production; ammonia and microbial N. In general, all pasture treatments showed a high true organic matter digestibility (&gt;800 g/kg), and tended to decrease in S3. In vitro fermentation of PFP and RGWC produced the highest total VFA concentration during S1 and S2, and no differences among pastures were observed in summer. Propionate proportion of total VFA was affected by pasture type and regrowth period, being higher for RGWC and S1, respectively. In vitro microbial N was higher for MIXED in S1, and PFP in S2 and S3. No pasture and regrowth period effects were observed for methane production and its proportion of total gas production. These results indicate that the in vitro fermentation products of a permanent fertilised pasture reach similar levels to those obtained from a sown pasture, and thus may be considered as a sustainable alternative for grazing livestock systems.

Growth dynamics and morphogenesis of Trachypogon plumosus under soil fertility correction levels and regrowth ages

The effects of soil fertility correction levels (control, liming, fertilization and liming + fertilization) and regrowth ages (21, 28, 35, 42, 49, 56, 63, 70, 77 and 84 days) on growth dynamics, forage yield and morphogenetic and structural characteristics of Trachypogon plumosus were assessed in Roraima´s savannas. Dry matter yields (DMY), absolute growth rate (AGR), tiller population density (TPD), number of live leaves (NLL), final leaf length (FLL), leaf area index (LAI), leaf elongation rate (LER) and leaf senescence rate (LSR) increased consistently with regrowth age, while average growth rate (AvGR), and leaf appearance rate (LAR) were inversely proportional to regrowth age. The grass showed high responsiveness to the soil fertility improvement. Liming + fertilization or fertilization alone promoted higher DMY (2,116 and 1,759 kg ha-1), AGR (40.5 and 33.6 kg ha-1.day), AvGR (32.5 and 27.9 kg ha-1.day), NLL (5.5 and 4.9 leaf tiller-1), LAR (0.119 and 0.109 leaf day-1 tiller-1), LER (2.53 and 2.06 cm day-1 tiller-1), FLL (22.1 and 18.9 cm), LAI (2.64 and 2.83) and TPD (762 and 725 tillers m-2). To maximize the forage use efficiency and to prevent losses to leaves senescence, it is recommended a regrowth period between 56 to 63 days for fertilization and liming + fertilization, and 63 to 70 days for control or liming pastures.

SYMBIOTIC NITROGEN-FIXING ACTIVITY AND YIELD POTENTIAL OF INOCULATED HEDYSARUM CORONARIUM IN ISRAEL

ABSTRACT Hedysarum coronarium L. has recently been introduced into Israel for evaluation as a “new” winter forage crop. The lack of a native rhizobial population suitable for this legume and the need for inoculation were assessed. Field inoculation experiments with effective Rhizobium strains, previously selected under greenhouse conditions, proved the benefits of symbiotically fixed N2 to yield potential and forage quality of H. coronarium. Seasonal changes in nodulation, plant dry matter accumulation and N2 (C2 H2)-fixation activity under field conditions were followed. The effect of defoliation on root nodule development and nitrogen fixation rate during the vegetative regrowth period are briefly discussed.

Effects of cutting height on shoot regrowth and forage yield of alfalfa (Medicago sativa L.) in a short‐term cultivation system

AbstractAlfalfa (Medicago sativa L.) has been cultivated increasingly widely in the arable area of the middle‐eastern regions of China as a short‐term (1 or 2 years) component of a forage–grain rotation system, but little is known about the harvesting technique for this legume in the short‐term rotation. This study investigated the effects of cutting height (0‐, 5‐ and 10‐cm stubble height above the soil surface) on shoot regrowth and forage yield of alfalfa in the second‐year growing season at two sites in Shandong Province, China. Forage yield at the first harvest was higher under lower cutting height (0 &gt; 5 &gt; 10 cm) at both sites due to greater length and weight of individual shoots harvested. At the site where plants were fertilized and irrigated after the first harvest, lower cutting height increased the number of buds during the early regrowth period and the number of shoots per plant at the second harvest, though it decreased the length and weight of individual shoots harvested. At the site without fertilizer and irrigation, lower cutting height delayed the sprouting of buds after defoliation, and decreased the length of shoots harvested at the second cut. Forage yield at the second harvest was ranked 0 ≈ 5 &gt; 10 cm under fertilizer and irrigation, and 0 ≈ 5 ≈ 10 cm under no fertilizer and irrigation. The path analysis showed that forage yield was affected primarily by the weight of individual shoots at the first cut and by shoot number per plant in the aftermath. Harvesting close to the ground is considered to be a management option to increase alfalfa yield in a short‐term forage production system subjected to irrigation and fertilizer.

Susceptibility ofListeria monocytogenesBiofilms and Planktonic Cultures to Hydrogen Peroxide in Food Processing Environments

Recent studies have indicated that Listeria monocytogenes formed biofilms on the surface of food processing equipment, and may survive sanitization treatments. The purpose of this study was to compare the susceptibility of L. monocytogenes grown in either a biofilm or planktonic culture when exposed to hydrogen peroxide (H(2)O(2)). Twelve strains of biofilm-forming L. monocytogenes and their planktonic counterparts were treated with various concentrations of H(2)O(2) (1, 6, and 10%), and the cell survival was then determined at 10-min exposure intervals. When grown as a biofilm, L. monocytogenes was significantly more resistant to H(2)O(2) than under planktonic culture conditions. Planktonic L. monocytogenes strains exhibited significantly different susceptibility to 1% H(2)O(2). Equally interestingly, biofilms of the 12 L. monocytogenes strains also inhibited different survival rates after being treated with 6 and 10% H(2)O(2). However, most of the biofilms recovered to a population of 2-9 log CFU/glass fiber filter (GFF) after a 24-h re-growth period. These results indicate that there was no significant correlation between the H(2)O(2) resistance of biofilm- and planktonic-cultured cells, and suggest that different mechanisms for the resistance to sanitation or disinfection underly the persistence of certain strains in food-processing environments.

Effects of ridge and furrow rainfall harvesting system on Elymus sibiricus yield in Bashang agro-pastoral zone of China

A ridge-furrow rainfall harvesting system (RFRHS) was designed to increase the available soil water for Elymus sibiricus artificial grassland in order to improve and stabilize its yield in the agro-pastoral zone of Bashang region in North China. Field experiments were conducted during the growth seasons in 2008 to 2010 to evaluate the effects of the RFRH system on soil temperature, soil water content and the yield of E. sibiricus. Specifically, the following three systems were investigated: ridge width 60 cm and furrow width 30 cm (MR60), ridge width 30 cm and furrow width 30 cm (MR30) and flat (CK). The results show that in regrowth periods, average daily minimum temperature of MR30 and MR60 in the furrow soil surface was 3.22 and 2.16°C, which were significantly higher than that of CK. Soil water content of MR60, was higher than that of MR30 and the latter was higher than that of CK in most of the experimental periods. Due to the improved hydrothermal condition, the three year average of annual yields of MR60 and MR30 was 3.14 and 2.77 t ha -1 , which was significantly higher and increased by 99

Changes in crude protein fractions of forage legumes during the spring growth and summer regrowth period

SUMMARYOnly a few previous studies have analysed the crude protein (CP) fractions of the Cornell Net Carbohydrate and Protein System during the growth period of forage legumes. The objective of the present study was to investigate the changes in CP fractions during the spring growth and summer–autumn regrowth period of five forage legume species (alfalfa (also known as lucerne,Medicago sativaL.), birdsfoot trefoil (Lotus corniculatusL.), kura clover (Trifolium ambiguumM.B.), red clover (Trifolium pratenseL.) and white clover (Trifolium repensL.)) grown in binary mixtures with perennial ryegrass (Lolium perenneL.) and also in pure stands (two red clover cultivars). Additionally, the specific polyphenol oxidase (PPO) activity was measured photometrically in the leaves of pure red clover swards. In both pure and mixed cropping, CP fraction A increased with advancing maturity, except for the legumes from mixed cropping in the summer–autumn growth period 2004 and 2005. The variation of CP fraction A was mostly positively related to the N yield and the amount of dinitrogen fixation. Although CP fraction A of pure red clover was negatively correlated with the specific PPO activity in the spring growth period, the specific PPO activity was less relevant for the variation of CP fraction A with respect to the whole growing season. CP fraction B generally made up the largest proportion of the CP. Pure red clover stands showed reducing amounts of CP fraction C during the growth period, whereas in legumes grown with ryegrass an increase was usually observed. Despite these differences, there was generally an increase of CP fraction C when the content of non-structural carbohydrates decreased. Red clover and birdsfoot trefoil herbage contained the highest proportions of CP fraction C in the CP, regardless of growth period and year. In conclusion, red clover and birdsfoot trefoil had a more favourable CP composition for ruminant nutrition compared to the other legume species, and in red clover this could not be clearly attributed to the specific PPO activity.