GeoLearn: Multi-media Resources

This paper examines the potential of pedagogically designed video demonstrations in supporting the learning requirements of students in the Spatial Information Sciences (DSIS). Currently, over three hundred full and part-time students in the College of Engineering and Built Environment undertake a module in Land Surveying each semester and although these students range in discipline and academic level (NQAI 6-8), they all share a need for basic information and instruction in the area of practical land-surveying techniques. To accommodate this highly practical subject area, 50% of contact time is normally dedicated to group-based field exercises, the results of which are formally assessed. To enhance the students’ practical learning experience in Land Surveying modules and provide a mobile (m)learning resource a number of short videos with voice-over instruction have been developed. These YouTube clips, of approximately three minutes in duration each, show the correct use of automatic levels and digital theodolites and can be directly accessed in the field via a web and video enabled mobile platform. This study highlight the effectiveness of designing high quality mlearning resource material for use in a wide range of disciplines by undergraduate students during their basic Land Surveying modules. Furthermore, it evaluates the effectiveness of this student-centric approach to practical learning in terms of learners’ potential for mlearning, learner motivation and also perceptions of understanding and retention with regard to course content for both full-time students and professional learners. Outcomes of this study indicate that the use of videos hosted on YouTube is very positive as it presents few barriers to learners in terms of access and usability

A Bayesian Approach to Directed Acyclic Graphs with a Candidate Graph

Directed acyclic graphs represent the dependence structure among variables. When learning these graphs from data, different amounts of information may be available for different edges. Although many methods have been developed to learn the topology of these graphs, most of them do not provide a measure of uncertainty in the inference. We propose a Bayesian method, baycn (BAYesian Causal Network), to estimate the posterior probability of three states for each edge: present with one direction ($X \rightarrow Y$), present with the opposite direction ($X \leftarrow Y$), and absent. Unlike existing Bayesian methods, our method requires that the prior probabilities of these states be specified, and therefore provides a benchmark for interpreting the posterior probabilities. We develop a fast Metropolis-Hastings Markov chain Monte Carlo algorithm for the inference. Our algorithm takes as input the edges of a candidate graph, which may be the output of another graph inference method and may contain false edges. In simulation studies our method achieves high accuracy with small variation across different scenarios and is comparable or better than existing Bayesian methods. We apply baycn to genomic data to distinguish the direct and indirect targets of genetic variants.Comment: Included analyses for data from GEUVADIS and GTE

Age-related differences in corticospinal excitability during observation and motor imagery of balance tasks

Postural control declines across adult lifespan. Non-physical balance training has been suggested as an alternative to improve postural control in frail/immobilized elderly people. Previous studies showed that this kind of training can improve balance control in young and older adults. However, it is unclear whether the brain of young and older adults is activated differently during mental simulations of balance tasks. For this purpose, soleus (SOL) and tibialis motor evoked potentials (MEPs) and SOL H- reflexes were elicited while 15 elderly (mean ± SD = 71 ± 4.6 years) and 15 young participants (mean ± SD = 27 ± 4.6 years) mentally simulated static and dynamic balance tasks using motor imagery (MI), action observation (AO) or the combination of AO and MI (AO + MI). Young subjects displayed significant modulations of MEPs that depended on the kind of mental simulation and the postural task. Elderly adults also revealed differences between tasks, but not between mental simulation conditions. Furthermore, the elderly displayed larger MEP facilitation during mental simulation (AGE-GROUP; F(1,28) = 5.9; p = 0.02) in the SOL muscle compared to the young and a task-dependent modulation of the tibialis background electromyography (bEMG) activity. H-reflex amplitudes and bEMG in the SOL showed neither task- nor age- dependent modulation. As neither mental simulation nor balance tasks modulated H- reflexes and bEMG in the SOL muscle, despite large variations in the MEP-amplitudes, there seems to be an age-related change in the internal cortical representation of balance tasks. Moreover, the modulation of the tibialis bEMG in the elderly suggests that aging partially affects the ability to inhibit motor output

Control strategies for late blight in organic potato production

This report was presented at the UK Organic Research 2002 Conference. Protective copper fungicides are currently used to control late blight in most organic production systems, but approval for their use in organic farming will be revoked in 2002. Evidence suggests that organic potato production will not be reliably economic in the absence of Cu. Current controls for late blight are reviewed including: variety selection/breeding for blight resistance, diversification strategies, agronomic strategies for the management of late blight, and alternative treatments to Cu-fungicides

The Effects of Peripheral Canopy on DGPS Performance on Forest Roads

The purpose of this study was to evaluate differential global positioning system (DGPS) positional accuracy on Irish forest roads with typical peripheral canopies. The peripheral canopy obstruction at 20 forest road sites in Roundwood State Forest, was determined using a hand-held clinometer and magnetic compass. This simple field technique permitted quantification of the canopy obstruction using graphical means and resulted in a graphical skyplot of each site. The equipment, one Trimble ProXRS DGPS unit and two Trimble 4000SSi units permitted determination of the DGPS accuracy (average of 2.9 m) and precision (average of 2.1 m) with a range of peripheral canopies. DGPS performance was quantified in terms of the average absolute error in positional dilution of precision (PDOP) (DPDOP = 1.6). The relationship between DPDOP and percentage of open sky was found to be statistically significant (r = 0.706, r = 0.001). Statistical analysis also indicated a strong relationship between relative precision and DPDOP (r = 0.796, r = 0.000). Satellite constellation in the measurement period was not the sole factor affecting DGPS useability. Three distinct classes of peripheral obstruction at road sites were defined (Class I: 100-66 %; Class II: 65-33 %; Class III: 32-0 % obstruction) and it was found that both DGPS accuracy (3.70 m, 3.23 m, 1.91 m, respectively) and precision (4.10 m, 2.43 m, 0.83 m, respectively) improved with decreasing peripheral obstruction. These classes may be used as a means of predicting signal attenuation which might be expected under particular forest canopy conditions elsewhere

All You Need to Know and More about the Diagnosis and Management of Rare Mold Infections

Invasive mold infections caused by molds other than Aspergillus spp. or Mucorales are emerging. The reported prevalences of infection due to these rare fungal pathogens vary among geographic regions, driven by differences in climatic conditions, susceptible hosts, and diagnostic capabilities. These rare molds-Fusarium, Lomentospora, and Scedosporium species and others-are difficult to detect and often show intrinsic antifungal resistance. Now, international societies of medical mycology and microbiology have joined forces and created the Global guideline for the diagnosis and management of rare mould infections: an initiative of the European Confederation of Medical Mycology in cooperation with the International Society for Human and Animal Mycology and the American Society for Microbiology (published in Lancet Infect Dis, https://doi.org/10.1016/S1473-3099(20)30784-2), with the goal of improving the diagnosis, treatment, prevention, and survival of persons with rare mold infections. The guideline provides cutting-edge guidance for the correct utilization and application of established and new diagnostic and therapeutic options

Ziram, a pesticide associated with increased risk for Parkinson's disease, differentially affects the presynaptic function of aminergic and glutamatergic nerve terminals at the Drosophila neuromuscular junction

Multiple populations of aminergic neurons are affected in Parkinson's disease (PD), with serotonergic and noradrenergic loci responsible for some non-motor symptoms. Environmental toxins, such as the dithiocarbamate fungicide ziram, significantly increase the risk of developing PD and the attendant spectrum of both motor and non-motor symptoms. The mechanisms by which ziram and other environmental toxins increase the risk of PD, and the potential effects of these toxins on aminergic neurons, remain unclear. To determine the relative effects of ziram on the synaptic function of aminergic versus non-aminergic neurons, we used live-imaging at the Drosophila melanogaster larval neuromuscular junction (NMJ). In contrast to nearly all other studies of this model synapse, we imaged presynaptic function at both glutamatergic Type Ib and aminergic Type II boutons, the latter responsible for storage and release of octopamine, the invertebrate equivalent of noradrenalin. To quantify the kinetics of exo- and endo- cytosis, we employed an acid-sensitive form of GFP fused to the Drosophila vesicular monoamine transporter (DVMAT-pHluorin). Additional genetic probes were used to visualize intracellular calcium flux (GCaMP) and voltage changes (ArcLight). We find that at glutamatergic Type Ib terminals, exposure to ziram increases exocytosis and inhibits endocytosis. By contrast, at octopaminergic Type II terminals, ziram has no detectable effect on exocytosis and dramatically inhibits endocytosis. In contrast to other reports on the neuronal effects of ziram, these effects do not appear to result from perturbation of the UPS or calcium homeostasis. Unexpectedly, ziram also caused spontaneous and synchronized bursts of calcium influx (measured by GCaMP) and electrical activity (measured by ArcLight) at aminergic Type II, but not glutamatergic Type Ib, nerve terminals. These events are sensitive to both tetrodotoxin and cadmium chloride, and thus appear to represent spontaneous depolarizations followed by calcium influx into Type II terminals. We speculate that the differential effects of ziram on Type II versus Type Ib terminals may be relevant to the specific sensitivity of aminergic neurons in PD, and suggest that changes neuronal excitability could contribute to the increased risk for PD caused by exposure to ziram. We also suggest that the fly NMJ will be useful to explore the synaptic effects of other pesticides associated with an increased risk of PD

Development and validation of sensitive real-time RT-PCR assay for broad detection of rabies virus

Rabies virus (RABV) remains one of the most important global zoonotic pathogens. RABV causes rabies, an acute encephalomyelitis associated with a high rate of mortality in humans and animals and affecting different parts of the world, particularly in Asia and Africa. Confirmation of rabies diagnosis relies on laboratory diagnosis, in which molecular techniques such as detection of viral RNA by reverse transcription polymerase chain reaction (RT-PCR) are increasingly being used.  In this study, two real-time quantitative RT-PCR assays were developed for large-spectrum detection of RABV, with a focus on African isolates. The primer and probe sets were targeted highly conserved regions of the nucleoprotein (N) and polymerase (L) genes.  The results indicated the absence of non-specific amplification and cross-reaction with a range of other viruses belonging to the same taxonomic family, i.e Rhabdoviridae, as well as negative brain tissues from various host species. Analytical sensitivity ranged between 100 to 10 standard RNA copies detected per reaction for N-gene and L-gene assays, respectively. Effective detection and high sensitivity of these assays on African isolates showed that they can be successfully applied in general research and used in diagnostic process and epizootic surveillance in Africa using a double-check strategy

Terrain Features and Architecture of Wolverine (Gulo gulo) Resting Burrows and Reproductive Dens on Arctic Tundra

Burrowing species rely on subterranean and subnivean sites to fulfill important life-history and behavioral processes, including predator avoidance, thermoregulation, resting, and reproduction. For these species, burrow architecture can affect the quality and success of such processes, since characteristics like tunnel width and chamber depth influence access by predators, thermal insulation, and energy spent digging. Wolverines (Gulo gulo) living in Arctic tundra environments dig burrows in snow during winter for resting sites and reproductive dens, but there are few published descriptions of such burrows. We visited 114 resting burrows and describe associated architectural characteristics and non-snow structure. Additionally, we describe characteristics of 15 reproductive den sites that we visited during winter and summer. Although many resting burrows were solely excavated in snow, most incorporated terrain structures including cliffs, talus, river shelf ice, thermokarst caves, and stream cutbanks. Burrows typically consisted of a single tunnel leading to a single chamber, though some burrows had multiple entrances, branching tunnels, or both. Tunnels in resting burrows were shorter than those in reproductive dens, and resting chambers were typically located at the deepest part of the burrow. Reproductive dens were associated with snowdrift-forming terrain features such as streambeds, cutbanks on lake edges, thermokarst caves, and boulders. Understanding such characteristics of Arctic wolverine resting and reproductive structures is critical for assessing anthropogenic impacts as snowpack undergoes climate-driven shifts.Les espèces fouisseuses dépendent de lieux enfouis sous la terre et sous la neige pour satisfaire leurs importants processus de vie et de comportement, y compris l’évitement des prédateurs, la thermorégulation, le repos et la reproduction. Pour ces espèces, l’architecture des terriers peut avoir des effets sur la qualité et la réussite des processus, car des caractéristiques comme la largeur des tunnels et la profondeur des chambres influencent l’accès aux terriers par les prédateurs, l’isolation thermique et l’énergie dépensée pour creuser. L’hiver, les carcajous (Gulo gulo) qui vivent dans les environnements de la toundra de l’Arctique creusent des terriers dans la neige afin de s’en servir comme aires de repos et comme tanières de reproduction. Cependant, peu de descriptions de tels terriers ont été publiées. Nous avons visité 114 terriers de repos, puis nous avons décrit leurs caractéristiques architecturales et les structures connexes n’étant pas recouvertes de neige. Par ailleurs, nous décrivons les caractéristiques de 15 tanières de reproduction que nous avons visitées en hiver et en été. Même si de nombreux terriers de repos ont été uniquement creusés dans la neige, la plupart des terriers incorporaient des structures topographiques, dont des falaises, des talus, de la glace de banquise, des grottes thermokarstiques et des hautes berges de cours d’eau. En général, les terriers étaient composés d’un seul tunnel menant à une seule chambre, bien que certains avaient plusieurs entrées, des galeries, ou les deux. Les tunnels des aires de repos étaient moins longs que ceux des tanières de reproduction, et les chambres de repos étaient généralement situées dans la partie la plus profonde des terriers. Les tanières de reproduction étaient installées dans des caractéristiques topographiques où s’amoncelle la neige, comme les lits de cours d’eau, les hautes berges de lacs, les grottes thermokarstiques et les rochers. Il est essentiel de comprendre les caractéristiques des structures de repos et de reproduction des carcajous de l’Arctique afin d’être en mesure d’évaluer les incidences anthropiques au moment où le manteau neigeux subit des changements liés au climat