Functional traits of individual varieties as determinants of growth and nitrogen use patterns in mixed stands of willow (Salix spp.)

Short rotation plantations of willows (Salix spp.) have high biomass production potential in many parts of the world, and may frequently support ecosystem services related to nutrient cycling. A plantation management enhancing favorable environmental impacts that are conducive to maintaining ecosystem services is a main challenge in establishing sustainable biomass production systems. There is evidence supporting the hypothesis that biomass production and nutrient cycling can be increased by supporting ecosystem niche differentiation (complementarity) through enhancing the number of plant species or varieties grown in the stand. However, the specific trait values of the individual components (e.g., varieties) in a mixed community could also be more important than the community diversity per se. We assessed, at community level, the plant trait profiles related to growth and nitrogen (N) use for four different Salix varieties that were taxonomically distinct at species or genotype level ('Bjorn', 'Jorr', 'Loden', 'Tora') and field-grown in unfertilized plots of pure and mixed commu-nities during one cutting cycle in Central Sweden. The aims were to use elements of functional growth analysis for exploring the mechanistic relationships between various traits related to growth and N use at stand level in our pure and mixed willow communities; and to address two hypotheses related to (i) the effect of diversity level on above-ground traits linked to growth, N uptake efficiency, N productivity and N conservation; and (ii) the influence of individual variety identities on the growth and N use traits observed in a mixture. Diversity level had no significant effect on the traits assessed here, and we thus found no evidence in support of our hypothesis that traits linked to growth, N uptake and use are significantly affected by the diversity level per se. In most but not all cases, the admixing effects on trait values were explained by the effects of the individual variety characteristics assessed in monocultures in combination with their relative share in the respective mixtures. The absence or presence of individual varieties strongly affected community-averaged (stand level) trait values. Therefore, the design of desirable variety mixtures is suggested that combine, for example, the high nutrient conversion efficiency that certain varieties achieve in mixed stands with the specific nutrient acquisition characteristics of other varieties

Deep Brain Stimulation of Caudal Zona Incerta and Subthalamic Nucleus in Patients with Parkinson's Disease: Effects on Diadochokinetic Rate

The hypokinetic dysarthria observed in Parkinson's disease (PD) affects the range, speed, and accuracy of articulatory gestures in patients, reducing the perceived quality of speech acoustic output in continuous speech. Deep brain stimulation (DBS) of the subthalamic nucleus (STN-DBS) and of the caudal zona incerta (cZi-DBS) are current surgical treatment options for PD. This study aimed at investigating the outcome of STN-DBS (7 patients) and cZi-DBS (7 patients) in two articulatory diadochokinesis tasks (AMR and SMR) using measurements of articulation rate and quality of the plosive consonants (using the percent measurable VOT metric). The results indicate that patients receiving STN-DBS increased in articulation rate in the Stim-ON condition in the AMR task only, with no effect on production quality. Patients receiving cZi-DBS decreased in articulation rate in the Stim-ON condition and further showed a reduction in production quality. The data therefore suggest that cZi-DBS is more detrimental for extended articulatory movements than STN-DBS

Optimized utilization of Salix-Perspectives for the genetic improvement toward sustainable biofuel value chains

Bioenergy will be one of the most important renewable energy sources in the conversion from fossil fuels to bio-based products. Short rotation coppice Salix could be a key player in this conversion since Salix has rapid growth, positive energy balance, easy to manage cultivation system with vegetative propagation of plant material and multiple harvests from the same plantation. The aim of the present paper is to provide an overview of the main challenges and key issues in willow genetic improvement toward sustainable biofuel value chains. Primarily based on results from the research project "Optimized Utilization of Salix" (OPTUS), the influence of Salix wood quality on the potential for biofuel use is discussed, followed by issues related to the conversion of Salix biomass into liquid and gaseous transportation fuels. Thereafter, the studies address genotypic influence on soil carbon sequestration in Salix plantations, as well as on soil carbon dynamics and climate change impacts. Finally, the opportunities for plant breeding are discussed using willow as a resource for sustainable biofuel production. Substantial phenotypic and genotypic variation was reported for different wood quality traits important in biological (i.e., enzymatic and anaerobic) and thermochemical conversion processes, which is a prerequisite for plant breeding. Furthermore, different Salix genotypes can affect soil carbon sequestration variably, and life cycle assessment illustrates that these differences can result in different climate mitigation potential depending on genotype. Thus, the potential of Salix plantations for sustainable biomass production and its conversion into biofuels is shown. Large genetic variation in various wood and biomass traits, important for different conversion processes and carbon sequestration, provides opportunities to enhance the sustainability of the production system via plant breeding. This includes new breeding targets in addition to traditional targets for high yield to improve biomass quality and carbon sequestration potential

Long term changes in stand structure and biomass production in short rotation willow coppice

Short rotation willow coppice (SRWC) is a recently commercialised agricultural crop in Sweden, producing biomass for energy. The expected lifespan of a SRWC plantation is more than 20 years, or at least 5 harvests. Consequently, understanding of long term stand development in relation to management, plant material and site characteristics is of great importance. The focus of this thesis is on SRWC biomass production during later cutting cycles. Long term development and dynamics have been studied during three cutting cycles by means of annual census of individual stools, scaled up to stand level. Methods for non-destructive biomass assessment, by means of allometric relations, have been developed and validated for different clones. A method for predicting willow shoot growth in field trials, under different nutrient and water conditions, based on characteristics found in pot-grown plants under corresponding conditions, has also been investigated. The best non-destructive method for assessing shoot weight of clones with bow-shaped and branching stems was found to be shoot dry weight related to the sum of the cross sectional areas of all shoots. In straight, un-branched clones, the measuring height could be elevated to 105 cm above stem base without loosing precision. A comparison of a destructive and a non-destructive method, applied on 12 different clones, showed a mean deviation of 2.5%. Stool mortality during the 1st cutting cycle was non-density dependent. Biomass production increased in the 2nd cutting cycle but high density dependent stool mortality at the end of the 2nd cutting cycle negatively influenced the production in the 3rd cutting cycle, which was lower than both the 1st and 2nd cutting cycle. A stool size hierarchy was established early and prevailed through all cutting cycles. Stool mortality occurred mainly among small stools. In the beginning of the 4th cutting cycle, biomass production stabilised due to compensatory growth of the remaining stools. Total leaf area and total nitrogen pool of pot-grown plants were good clone-specific characters for predicting shoot biomass growth in the field during the first cutting cycle and may be used for shortening the time needed to characterise new clones. The results suggest that sustainability in SRWC systems is enhanced by matching clone and site and adapting fertilisation and harvest timing to actual stand development

Method-of-limits : Cold and warm perception thresholds at proximal and distal body regions

Objective: Thermal quantitative sensory testing with the 'Method-of-Limits' is an established rationale for detection of small nerve fiber dysfunction, but adequate reference values are crucial for such evaluations, regardless of the underlying cause. This study assessed reference data for cold- (CPT) and warm- (WPT) perception thresholds at both proximal and distal sites in eight body regions of the lower and upper extremities, all determined within the same test session for each subject. Methods: Seventy-five healthy subjects (aged 16-72 years) were tested according to the method-of-limit for CPT and WPT at the dorsum of the foot, the medial and lateral lower leg, the ventral thigh, the thenar eminence, the radial and ulnar part of the lower arm, and the anterior deltoid part of the upper arm. Results: Overall, thermal perception thresholds (TPT) varied with test location, but were higher in the lower than in the upper part of the body, also WPT were generally higher than CPT. TPT at the dorsum foot highly correlated with age, while inconsistent correlations were noted between TPT and age or height at other tested locations. Conclusion: This study describes for the first time reference values at eight defined body regions, at both proximal and distal sites. Significance: The report enables refined evaluations of general small nerve fiber function, as assessed by quantitative thermal sensory testing with the Method-of-Limits

Co-digestion of salix and manure for biogas: importance of clone choice, coppicing frequency and reactor setup

Animal manure represents a major source of renewable energy that can be converted into biogas using anaerobic digestion. In order to most efficiently utilize this resource, it can be co-digested with energy dense, high biomethanation potential feedstocks such as energy crops. However, such feedstocks typically require pretreatments which are not feasible for small-scale facilities. We investigated the use of single-stage and the sequential co-digestion of comminuted but otherwise non-pretreated Salix with animal manure, and further investigated the effects of coppicing frequency and clone choice on biomethanation potential and the area requirements for a typical Swedish farm-scale anaerobic digester using Salix and manure as feedstock. In comparison with conventional single-stage digestion, sequential digestion increased the volumetric and specific methane production by 57% to 577 NmL L-1 d-1 and 192 NmL (g volatile solids (VS))−1, respectively. Biomethanation potential was the highest for the two-year-old shoots, although gains in biomass productivity suggest that every-third-year coppicing maybe a better strategy for supplying Salix feedstock for anaerobic digestion. The biomethane production performance of the sequential digestion of minimally pretreated Salix mirrors that of hydrothermally pretreated hardwoods and may provide an option where such pretreatments are not feasible

A video-based system for recording speech movements in three dimensions.

An examination of speech articulator movement used a video-based system for tracking & recording movement in three dimensions - the MacReflex(R). The system is noninvasive with no hazardous radiation or electromagnetic field, & no wires to impede movement. The facility is currently used at the Depts of Clinical Neurophysiology & Clinical Oral Physiology, U of Umea, to study strategies for motor control of precise movement in the hand, neck, & mandible, & in various neurological disabilities

Weed community trajectories in cereal and willow cultivations after termination of a willow short rotation coppice

According to guidelines for willow short rotation coppice (SRC), weeding is needed during establishment, while weed populations which develop later under a well-established willow canopy do not require control. However, farmers are concerned that weeds which develop in SRC may result in long-lasting weed infestations in succeeding crops after SRC termination. We assessed the effects of two SRC-termination methods (with shallow and deep soil cultivation) on the development of the weed flora in a cereal system (CS) and in SRC during six seasons. Richness, ground cover, life-cycle strategy and composition of the weed species, and their environmental requirements (inferred from Ellenberg index) were evaluated. SRC-termination method had no effect on the weed community trajectories in the succeeding SRC and CS. However, cropping system and growing season had significant impacts on species richness, ground cover and composition of the weed flora. Differences in weed communities over time and between cropping systems were related to the impact of cropping systems on factors such as light, soil moisture, nitrogen level, and soil reaction, as inferred from the Ellenberg index. After termination of the old willow cultivation, the weed flora of the SRC and CS rapidly diverged and approached the weed flora characteristic for old willow stands and non-weeded old cereal plot, respectively. We conclude that willow stands can be converted, regardless of termination method, either into willow or cereal cultivations without additional risk of weed infestations other than those specific for their respective cropping systems. Furthermore, willow cultivations in agriculture contribute to floristic diversity at the landscape scale