Reduced tillage in north-west Europe—A review

The main features of the climate and soils of the main crop production areas of different countries in north-west Europe are outlined, and the main crops grown are summarised. The need for tillage is considered; provided that suitable conditions exist for germination, root growth is most likely to be influenced by mechanical impedance and aeration. Traditional tillage may not always be necessary and may hinder timely sowing of crops. Shallow tillage can facilitate planting a larger area of crops closer to the optimum dates in autumn and in spring, which also saves energy and labour.Research experience with reduced tillage over the last 20–25 years is reviewed. Shallow tillage has been as good as mouldboard ploughing at the traditional depth in most countries on a wide range of soil types, if weed control was satisfactory. Direct drilling has often proved satisfactory in the absence of crop residues for autumn sown crops (wheat, barley, oil-seed rape and beans) where drainage (and therefore soil aeration) was not limiting. Direct drilling has not generally been successful for spring sown crops. Direct drilling is inappropriate for root crops, but strip tillage for sugar beet may become practicable. Some research on soil conditions associated with these experiments is considered.Crop residues are a major constraint to shallow tillage or direct drilling of autumn sown crops. The limitations of reduced tillage due to inadequate weed control, wheel-traffic damage and unsatisfactory drainage are reviewed. The need for occasional deep loosening is also discussed. Where the amount of residues is small, much tillage may be unnecessary, except to relieve compaction by wheels; bed systems or wide-span gantries to avoid wheel damage could become practical developments for some crops.     

<Emphasis Type="Italic">Lupinus albus</Emphasis> Conglutin Gamma Modifies the Gene Expressions of Enzymes Involved in Glucose Hepatic Production <Emphasis Type="Italic">In Vivo</Emphasis>

Lupinus albus seeds contain conglutin gamma (Cγ) protein, which exerts a hypoglycemic effect and positively modifies proteins involved in glucose homeostasis. Cγ could potentially be used to manage patients with impaired glucose metabolism, but there remains a need to evaluate its effects on hepatic glucose production. The present study aimed to analyze G6pc, Fbp1, and Pck1 gene expressions in two experimental animal models of impaired glucose metabolism. We also evaluated hepatic and renal tissue integrity following Cγ treatment. To generate an insulin resistance model, male Wistar rats were provided 30% sucrose solution ad libitum for 20 weeks. To generate a type 2 diabetes model (STZ), five-day-old rats were intraperitoneally injected with streptozotocin (150 mg/kg). Each animal model was randomized into three subgroups that received the following oral treatments daily for one week: 0.9% w/v NaCl (vehicle; IR-Ctrl and STZ-Ctrl); metformin 300 mg/kg (IR-Met and STZ-Met); and Cγ 150 mg/kg (IR-Cγ and STZ-Cγ). Biochemical parameters were assessed pre- and post-treatment using colorimetric or enzymatic methods. We also performed histological analysis of hepatic and renal tissue. G6pc, Fbp1, and Pck1 gene expressions were quantified using real-time PCR. No histological changes were observed in any group. Post-treatment G6pc gene expression was decreased in the IR-Cγ and STZ-Cγ groups. Post-treatment Fbp1 and Pck1 gene expressions were reduced in the IR-Cγ group but increased in STZ-Cγ animals. Overall, these findings suggest that Cγ is involved in reducing hepatic glucose production, mainly through G6pc inhibition in impaired glucose metabolism disorders.     

Dual-component video image analysis system (VIASCAN) as a predictor of beef carcass red meat yield percentage and for augmenting application of USDA yield grades

An improved ability to quantify differences in the fabrication yields of beef carcasses would facilitate the application of value-based marketing. This study was conducted to evaluate the ability of the Dual-Component Australian VIASCAN to 1) predict fabricated beef subprimal yields as a percentage of carcass weight at each of three fat-trim levels and 2) augment USDA yield grading, thereby improving accuracy of grade placement. Steer and heifer carcasses (n = 240) were evaluated using VIASCAN, as well as by USDA expert and online graders, before fabrication of carcasses to each of three fat-trim levels. Expert yield grade (YG), online YG, VIASCAN estimates, and VIASCAN estimated ribeye area used to augment actual and expert grader estimates of the remaining YG factors (adjusted fat thickness, percentage of kidney-pelvic-heart fat, and hot carcass weight), respectively, 1) accounted for 51, 37, 46, and 55% of the variation in fabricated yields of commodity-trimmed subprimals, 2) accounted for 74, 54, 66, and 75% of the variation in fabricated yields of closely trimmed subprimals, and 3) accounted for 74, 54, 71, and 75% of the variation in fabricated yields of very closely trimmed subprimals. The VIASCAN system predicted fabrication yields more accurately than current online yield grading and, when certain VIASCAN-measured traits were combined with some USDA yield grade factors in an augmentation system, the accuracy of cutability prediction was improved, at packing plant line speeds, to a level matching that of expert graders applying grades at a comfortable rate.     

Effects of a unique application of electrical stimulation on tenderness, color, and quality attributes of the beef longissimus muscle

This study evaluated effects of four uniquely applied beef carcass electrical stimulation (ES) treatments on USDA grade factors, muscle color, subprimal purge loss, cooked steak weight loss, and cooked steak tenderness. One side of each (n = 284) beef carcass was subjected to ES using one of four treatments (medium voltage for medium duration, MVMD; medium voltage for long duration, MVLD; high voltage for medium duration, HVMD; or high voltage for long duration, HVLD) and was compared to its corresponding non-ES control side. Electrical stimulation of beef sides was applied focusing on middle meats while preventing severe contraction of the round and chuck. From matched (ES and control) sides of 120 carcasses (10 each of Select, low Choice, and upper two-thirds of Choice in each of the four ES treatments), longissimus steaks (2.5 cm thick) were cooked and used for Warner-Bratzler shear force (WBS) analysis. Mean marbling scores (n = 284) for stimulated sides did not differ (P = .923) from those for control sides within ES treatment classes. Mean values for CIE L*, a*, and b* of lean color (n = 284) were higher (P < .05) for MVMD, MVLD, HVMD, and HVLD treated sides than for the respective control sides. When WBS values for steaks were adjusted to an equal visual degree of doneness, WBS values (n = 120) were lower (P < .05) for ES treated sides than for control sides for all four types of ES application treatments. Treatment responses were not influenced by USDA Quality Grade group. For those carcasses for which the control sides had WBS values greater than 4.5 kg, matching sides treated with MVMD, MVLD, HVMD, or HVLD had WBS values less than 4.5 kg 50, 88, 60, and 75% of the time, respectively. Mean cooked steak weight loss (n = 120), adjusted to an equal visual degree of doneness, and mean purge loss (n = 24) did not differ with ES treatment.     

Carbon sequestration in the trees, products and soils of forest plantations: an analysis using UK examples

A carbon-flow model for managed forest plantations was used to estimate carbon storage in UK plantations differing in Yield Class (growth rate), thinning regime and species characteristics. Time-averaged, total carbon storage (at equilibrium) was generally in the range 40-80 Mg C ha(-1) in trees, 15-25 Mg C ha(-1) in above- and belowground litter, 70-90 Mg C ha(-1) in soil organic matter and 20-40 Mg C ha(-1) in wood products (assuming product lifetime equalled rotation length). The rate of carbon storage during the first rotation in most plantations was in the range 2-5 Mg C ha(-1) year(-1).A sensitivity analysis revealed the following processes to be both uncertain and critical: the fraction of total woody biomass in branches and roots; litter and soil organic matter decomposition rates; and rates of fine root turnover. Other variables, including the time to canopy closure and the possibility of accelerated decomposition after harvest, were less critical. The lifetime of wood products was not critical to total carbon storage because wood products formed only a modest fraction of the total.The average increase in total carbon storage in the tree-soil-product system per unit increase in Yield Class (m(3) ha(-1) year(-1)) for unthinned Picea sitchensis (Bong.) Carr. plantations was 5.6 Mg C ha(-1). Increasing the Yield Class from 6 to 24 m(3) ha(-1) year(-1) increased the rate of carbon storage in the first rotation from 2.5 to 5.6 Mg C ha(-1) year(-1) in unthinned plantations. Thinning reduced total carbon storage in P. sitchensis plantations by about 15%, and is likely to reduce carbon storage in all plantation types.If the objective is to store carbon rapidly in the short term and achieve high carbon storage in the long term, Populus plantations growing on fertile land (2.7 m spacing, 26-year rotations, Yield Class 12) were the best option examined. If the objective is to achieve high carbon storage in the medium term (50 years) without regard to the initial rate of storage, then plantations of conifers of any species with above-average Yield Classes would suffice. In the long term (100 years), broadleaved plantations of oak and beech store as much carbon as conifer plantations. Mini-rotations (10 years) do not achieve a high carbon storage.     

The diving behaviour of little penguins in Western Australia predisposes them to risk of injury by watercraft

1. The most western little penguin colony globally, and the most northern in Western Australia (WA) is found on Penguin Island, WA. The penguins use coastal bays that are also used extensively by recreational watercraft. These penguins have been found to either dive predominantly to shallow depths of 1–5 m or to depths >8 m. It is thus hypothesized that (a) both the shallow and deeper diving penguins can potentially be disturbed or injured by these watercraft but that the risk will differ between the two diving strategies, and (b) that risk of injury for both is greater during the summer and autumn, when people are more likely to use watercraft.
2. This was tested by attaching data loggers to little penguins during chick rearing and by investigating necropsy records. Diving activity was studied for the very shallow and relatively deeper diving penguins separately, and we considered the penguins were vulnerable to interactions with watercraft when they were within the top 2 m of the water column or at the surface.
3. Shallow‐diving penguins executed >1,200 dives per day, 64% of dives occurred within the top 2 m, and they were vulnerable for approximately two‐thirds of their time at sea. The deeper diving penguins executed fewer dives. Almost half of dives were to ≥10 m, yet they were vulnerable for almost one‐third of their time at sea. Their post‐dive recovery was also longer. Thus, the risk of interaction from watercraft differs depending on the diving behaviour.
4. This study highlights the potential impact to little penguins throughout Australia and New Zealand.

     

Imaging crystals, polymers, and processes in water with the atomic force microscope

The atomic force microscope (AFM) can be used to image the surface of both conductors and nonconductors even if they are covered with water or aqueous solutions. An AFM was used that combines microfabricated cantilevers with a previously described optical lever system to monitor deflection. Images of mica demonstrate that atomic resolution is possible on rigid materials, thus opening the possibility of atomic-scale corrosion experiments on nonconductors. Images of polyalanine, an amino acid polymer, show the potential of the AFM for revealing the structure of molecules important in biology and medicine. Finally, a series of ten images of the polymerization of fibrin, the basic component of blood clots, illustrate the potential of the AFM for revealing subtle details of biological processes as they occur in real time.     

Cellular and subcellular heterogeneity of [Ca2+]i in single heart cells revealed by fura-2

Digital imaging of calcium indicator signals (fura-2 fluorescence) from single cardiac cells has revealed different subcellular patterns of cytoplasmic calcium ion concentration ([Ca2+]i) that are associated with different types of cellular appearance and behavior. In any population of enzymatically isolated rat heart cells, there are mechanically quiescent cells in which [Ca2+]i is spatially uniform, constant over time, and relatively low; spontaneously contracting cells, which have an increased [Ca2+]i, but in which the spatial uniformity of [Ca2+]i is interrupted periodically by spontaneous propagating waves of high [Ca2+]i; and cells that are hypercontracted (rounded up) and that have higher levels of [Ca2+]i than the other two types. The observed cellular and subcellular heterogeneity of [Ca2+]i in isolated cells indicates that experiments performed on suspensions of cells should be interpreted with caution. The spontaneous [Ca2+]i fluctuations previously observed without spatial resolution in multicellular preparations may actually be inhomogeneous at the subcellular level.     

Purkinje cell degeneration (pcd) phenotypes caused by mutations in the axotomy-induced gene, Nna1

The classical recessive mouse mutant, Purkinje cell degeneration (pcd), exhibits adult-onset degeneration of cerebellar Purkinje neurons, retinal photoreceptors, olfactory bulb mitral neurons, and selected thalamic neurons, and has defective spermatogenesis. Here we identify Nna1 as the gene mutated in the original pcd and two additional pcd alleles (pcd2J and pcd3J). Nna1 encodes a putative nuclear protein containing a zinc carboxypeptidase domain initially identified by its induction in spinal motor neurons during axonal regeneration. The present study suggests an unexpected molecular link between neuronal degeneration and regeneration, and its results have potential implications for neurodegenerative diseases and male infertility.