Experience-driven plasticity of visual cortex limited by myelin and Nogo receptor

Monocular deprivation normally alters ocular dominance in the visual cortex only during a postnatal critical period (20 to 32 days postnatal in mice). We find that mutations in the Nogo-66 receptor (NgR) affect cessation of ocular dominance plasticity. In NgR-/- mice, plasticity during the critical period is normal, but it continues abnormally such that ocular dominance at 45 or 120 days postnatal is subject to the same plasticity as at juvenile ages. Thus, physiological NgR signaling from myelin-derived Nogo, MAG, and OMgp consolidates the neural circuitry established during experience-dependent plasticity. After pathological trauma, similar NgR signaling limits functional recovery and axonal regeneration.     

Using herd records to monitor transition cow survival, productivity, and health.

There is no single monitor that can fully characterize the success of a transition cow management program in a herd. Rather we must rely on a group of key monitors. Table 5 outlines the key indices and targets that we use in herd investigations. By using these monitors, effective transition cow programs can be differentiated from problematic ones, and many of the problems can be resolved for the good of the herd owners, dairy laborers, and most of all, the cows. Development of more sophisticated monitors and software with stronger epidemiologic structure will allow for better analysis of programs in the future.     

Molecular epidemiology of Cryptosporidium subtypes in cattle in England

Samples of Cryptosporidium spp., collected in a cross-sectional study of calves (median age 26 days) from 41 farms in Cheshire, UK, underwent molecular typing. The aim was to determine naturally occurring species/genotypes and to investigate transmission pathways within a local area. Of 60 positive samples, 54 were sequenced at an 18S rRNA locus and 51 were typed at a GP60 locus. C. parvum was identified in 50 samples, three cases were C. bovis and one was Cryptosporidium deer-like genotype. Six GP60 subgenotypes were identified. One subgenotype (IIaA15G2R1) was highly prevalent throughout the study area. A single subgenotype was identified on 20/22 farms. Two subgenotypes were found on 2/22 farms. The spatial scan statistic detected a cluster of subgenotype IIaA15G2R1 comprising seven farms. This suggests local transmission of the parasite between farms. As most of the isolates detected were the potentially zoonotic C. parvum allele IIa, intervention strategies should be considered to reduce the threat to public health. Biosecurity measures may reduce transmission between farms and result in lower levels of environmental contamination.     

Advanced process control of irrigation: the current state and an analysis to aid future development

Control engineering approaches may be applied to irrigation management to make better use of available irrigation water. These methods of irrigation decision-making are being developed to deal with spatial and temporal variability in field properties, data availability and hardware constraints. One type of control system is advanced process control which, in an irrigation context, refers to the incorporation of multiple aspects of optimisation and control. Hence, advanced process control is particularly suited to the management of site-specific irrigation. This paper reviews applications of advanced process control in irrigation: mathematical programming, linear quadratic control, artificial intelligence, iterative learning control and model predictive control. From the literature review, it is argued that model-based control strategies are more realistic in the soil–plant–atmosphere system using process simulation models rather than using ‘black-box’ crop production models. It is also argued that model-based control strategies can aim for specific end of season characteristics and hence may achieve optimality. Three control systems are identified that are robust to data gaps and deficiencies and account for spatial and temporal variability in field characteristics, namely iterative learning control, iterative hill climbing control and model predictive control: from consideration of these three systems it is concluded that the most appropriate control strategy depends on factors including sensor data availability and grower’s specific performance requirements. It is further argued that control strategy development will be driven by the available sensor technology and irrigation hardware, but also that control strategy options should also drive future plant and soil moisture sensor development.     

Attempts to determine the effects of forest cover on stream flow by direct hydrological measurements in Los Negros,Bolivia

Underlying many payments for watershed services (PWS) schemes in tropical montane forest contexts is the assumption of a direct positive relationship between forest cover and dry season stream flow. We developed a low cost research program to assess the forest cover-stream flow relationship in the Los Negros watershed in eastern Bolivia. We asked three questions: (1) can watersheds that are similar enough to undertake paired catchment studies be identified using only simple parameters such as size, aspect and geographic proximity; (2) can a functioning locally based hydrological monitoring system be set up for less than $10 000 by training local farmers to collect hydrological data, and (3) can such data be used to improve the functioning of a PWS initiative? A land use map of the upper Los Negros valley was created from a 2005 Landsat image and a digital elevation model used to calculate physical and hydrological properties of 10 sub-watersheds. Farmers measured stream flow rates in these sub-watersheds from 2005 to 2008 and maintained 10 automatic rain gauges. We found no relationship between forest cover and stream flow. This may indicate that no such relationship exists, but could also reflect the short period of the study, the low quality of the data, and the fact that the sub-watersheds had relatively similar forest coverage (54–76%). We conclude that (1) watersheds can be identified as “similar-enough-for-analysis” using the criteria of size, aspect and proximity without undertaking further research, (2) a useful hydrological monitoring system can be developed for <$10,000 and (3) although our local farmers did not collect sufficiently high quality data to fully explore the forest/water relationship in Los Negros, with improvements in methodologies, low cost, locally based monitoring has the potential to be an important component of future PWS initiatives. We recommend that stream discharge should be calculated directly; only the most locally relevant hydrological criteria, rather than scientifically complete criteria, should be monitored; locally based monitoring must be institutionalized to reduce staff turnover and hydrological monitoring must be embedded within a context that makes it socially acceptable.