No Adverse Effect of Genetically Modified Antifungal Wheat on Decomposition Dynamics and the Soil Fauna Community – A Field Study

The cultivation of genetically modified (GM) plants has raised several environmental concerns. One of these concerns regards non-target soil fauna organisms, which play an important role in the decomposition of organic matter and hence are largely exposed to GM plant residues. Soil fauna may be directly affected by transgene products or indirectly by pleiotropic effects such as a modified plant metabolism. Thus, ecosystem services and functioning might be affected negatively. In a litterbag experiment in the field we analysed the decomposition process and the soil fauna community involved. Therefore, we used four experimental GM wheat varieties, two with a race-specific antifungal resistance against powdery mildew (Pm3b) and two with an unspecific antifungal resistance based on the expression of chitinase and glucanase. We compared them with two non-GM isolines and six conventional cereal varieties. To elucidate the mechanisms that cause differences in plant decomposition, structural plant components (i.e. C∶N ratio, lignin, cellulose, hemicellulose) were examined and soil properties, temperature and precipitation were monitored. The most frequent taxa extracted from decaying plant material were mites (Cryptostigmata, Gamasina and Uropodina), springtails (Isotomidae), annelids (Enchytraeidae) and Diptera (Cecidomyiidae larvae). Despite a single significant transgenic/month interaction for Cecidomyiidae larvae, which is probably random, we detected no impact of the GM wheat on the soil fauna community. However, soil fauna differences among conventional cereal varieties were more pronounced than between GM and non-GM wheat. While leaf residue decomposition in GM and non-GM wheat was similar, differences among conventional cereals were evident. Furthermore, sampling date and location were found to greatly influence soil fauna community and decomposition processes. The results give no indication of ecologically relevant adverse effects of antifungal GM wheat on the composition and the activity of the soil fauna community

Short-Term Visual Deprivation Does Not Enhance Passive Tactile Spatial Acuity

An important unresolved question in sensory neuroscience is whether, and if so with what time course, tactile perception is enhanced by visual deprivation. In three experiments involving 158 normally sighted human participants, we assessed whether tactile spatial acuity improves with short-term visual deprivation over periods ranging from under 10 to over 110 minutes. We used an automated, precisely controlled two-interval forced-choice grating orientation task to assess each participant's ability to discern the orientation of square-wave gratings pressed against the stationary index finger pad of the dominant hand. A two-down one-up staircase (Experiment 1) or a Bayesian adaptive procedure (Experiments 2 and 3) was used to determine the groove width of the grating whose orientation each participant could reliably discriminate. The experiments consistently showed that tactile grating orientation discrimination does not improve with short-term visual deprivation. In fact, we found that tactile performance degraded slightly but significantly upon a brief period of visual deprivation (Experiment 1) and did not improve over periods of up to 110 minutes of deprivation (Experiments 2 and 3). The results additionally showed that grating orientation discrimination tends to improve upon repeated testing, and confirmed that women significantly outperform men on the grating orientation task. We conclude that, contrary to two recent reports but consistent with an earlier literature, passive tactile spatial acuity is not enhanced by short-term visual deprivation. Our findings have important theoretical and practical implications. On the theoretical side, the findings set limits on the time course over which neural mechanisms such as crossmodal plasticity may operate to drive sensory changes; on the practical side, the findings suggest that researchers who compare tactile acuity of blind and sighted participants should not blindfold the sighted participants

New predictive value of optical coherence tomography analysis in the diagnosis of idiopathic intracranial hypertension

Objective Idiopathic Intracranial Hypertension (IIH) was first reported in 1897 as “Pseudo tumor Cerebri” when lumbar puncture was initiated in medicine. However, it is still a challenging diagnosis for many neurologists and ophthalmologists. Likewise, the sequela of IIH can be debilitating overall health and quality of life in most patients. This report presents the evolving diagnostic modalities that are different from mainstream IIH reports on gender, obesity and headaches ratios. We believe, using standard optical coherence tomography (OCT) can allow for a much earlier and more accurate diagnosis of IIH, with marked reduction in visual loss morbidity. Methods Retrospective, observational method was used to review 171 patients’ charts with suspected IIH over the past 12 years. The OCT of optic nerve and Macula was conducted by considering a list of signs and symptoms. Brain MRI, lumbar puncture, and our standard laboratory workups for optic neuropathies and visual fields were done. Visual Evoked Potentials were performed by neurologists. For purpose of this paper all IIH diagnosis fit Dandy diagnosis criteria of pseudo tumor cerebri as having a normal MRI. Results We evaluated 164 cases that had LPs done due to our proposed OCT Patterns to rule out IIH with no bio-microscopic evidence of overt papilledema. The majority of LP positive patients had some degree of visual field damage. Twenty out of 164 cases had false positive OCTs (with negative LPs) 88% accuracy in OCT diagnosis of IIH. No false positive OCT in Pattern-I. Conclusion Four different OCT diagnostic Patterns presented for IIH cases. The demographics of the patients considered having IIH by OCT Patterns I-IV and proven by positive LP; do not fit the classic demographic patterns. Classically, IIH has been reported to be observed in obese females with headaches and visible papilledema. Our findings put this classic set of presenting signs into question

Behavioural adaptation of Coquillettidia (Coquillettidia) richiardii larvae to underwater life: environmental cues governing plant-insect interaction

International audienceDensely overgrown pre-alpine permanent aquatic habitats are overrun by the mosquito Coquillettidia (Coquillettidia) richiardii (Ficalbi) (Diptera: Culicidae). The invasive potential of this insect depends on the ability of its larvae to survive on the roots of emergent aquatic macrophytes. In order to characterize this particular ecological niche, which is out of reach for a direct investigation, environmental factors likely to influence the interaction between larvae and host plant roots were investigated using a simplified laboratory microcosm. Environmental light and oxygen concentrations appeared to be the main factors influencing larval attachment, a dark anoxic environment being significantly more favourable. Carbon dioxide produced by the root system of the host plant appeared to be an attractive cue for larval attachment. Knowledge of the hierarchy of these environmental factors may enable us to better understand the ecological traits of larval C. richiardii in deep water. With regard to their management, new ecological data are required to develop a long-term control strategy against Coquillettidia mosquitoes