63 research outputs found
Using the dendro-climatological signal of urban trees as a measure of urbanization and urban heat island
Using dendroclimatological techniques this study investigates whether inner city tree-ring width (TRW) chronologies from eight tree species (ash, beech, fir, larch, lime, sessile and pedunculate oak, and pine) are suitable to examine the urban heat island of Berlin, Germany. Climate-growth relationships were analyzed for 18 sites along a gradient of increasing urbanization covering Berlin and surrounding rural areas. As a proxy for defining urban heat island intensities at each site, we applied urbanization parameters such as building fraction, impervious surfaces, and green areas. The response of TRW to monthly and seasonal air temperature, precipitation, aridity, and daily air-temperature ranges were used to identify climate-growth relationships. Trees from urban sites were found to be more sensitive to climate compared to trees in the surrounding hinterland. Ring width of the deciduous species, especially ash, beech, and oak, showed a high sensitivity to summer heat and drought at urban locations (summer signal), whereas conifer species were found suitable for the analysis of the urban heat island in late winter and early spring (winter signal).
The summer and winter signals were strongest in tree-ring chronologies when the urban heat island intensities were based on an area of about 200Â m to 3000Â m centered over the tree locations, and thus reflect the urban climate at the scale of city quarters. For the summer signal, the sensitivity of deciduous tree species to climate increased with urbanity.
These results indicate that urban trees can be used for climate response analyses and open new pathways to trace the evolution of urban climate change and more specifically the urban heat island, both in time and space
A novel SOD1 splice site mutation associated with familial ALS revealed by SOD activity analysis
More than 145 mutations have been found in the gene CuZn-Superoxide dismutase (SOD1) in patients with amyotrophic lateral sclerosis (ALS). The vast majority are easily detected nucleotide mutations in the coding region. In a patient from a Swiss ALS family with half-normal erythrocyte SOD1 activity, exon flanking sequence analysis revealed a novel thymine to guanine mutation 7 bp upstream of exon 4 (c.240-7T>G). The results of splicing algorithm analyses were ambiguous, but five out of seven analysis tools suggested a potential novel splice site that would add six new base pairs to the mRNA. If translated, this mRNA would insert Ser and Ile between Glu78 and Arg79 in the SOD1 protein. In fibroblasts from the patient, the predicted mutant transcript and the mutant protein were both highly expressed, and despite the location of the insertion into the metal ion-binding loop IV, the SOD1 activity appeared high. In erythrocytes, which lack protein synthesis and are old compared with cultured fibroblasts, both SOD1 protein and enzymic activity was 50% of controls. Thus, the usage of the novel splice site is near 100%, and the mutant SOD1 shows the reduced stability typical of ALS-associated mutant SOD1s. The findings suggests that this novel intronic mutation is causing the disease and highlights the importance of wide exon-flanking sequencing and transcript analysis combined with erythrocyte SOD1 activity analysis in comprehensive search for SOD1 mutations in ALS. We find that there are potentially more SOD1 mutations than previously reporte
Nine hole peg test and transcranial magnetic stimulation: useful to evaluate dexterity of the hand and disease progression in amyotrophic lateral sclerosis
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with involvement of the upper and lower motor neurons. Since the loss of fine motor skills is one of the earliest signs of ALS, the hypothesis was tested if the nine hole PEG test (NHPT) and transcranial magnet stimulation (TMS) with resting-motor threshold (RMT) could be useful in monitoring disease progression. Methods. We examined 28 ALS patients and 27 age-matched healthy controls. ALS patients and healthy controls underwent the nine hole peg test (NHPT) and TMS with RMT. Measurements in patients were repeated after three and six months. Results. At baseline, the median NHPT durations were 1,4-fold longer (p < 0.001), and TMS scores showed a significant 0.8-fold smaller score in ALS patients compared with healthy controls (p < 0.001). The comparison of three and six months versus baseline revealed significant differences for NHPT durations and ALSFRS-R in patients, whereas TMS scores did not significantly differ in the patients. Conclusion. NHPT seems to be a good tool to evaluate dexterity of the hand and the progression of the disease in ALS patients. TMS RMT to the hand muscles seems to be poorly qualified to evaluate the dexterity of the hand function and the course of the disease
Quality Control of Motor Unit Number Index (MUNIX) Measurements in 6 Muscles in a Single-Subject “Round-Robin” Setup
Background
Motor Unit Number Index (MUNIX) is a neurophysiological measure that provides an index
of the number of lower motor neurons in a muscle. Its performance across centres in healthy
subjects and patients with Amyotrophic Lateral Sclerosis (ALS) has been established, but
inter-rater variability between multiple raters in one single subject has not been
investigated.
Objective
To assess reliability in a set of 6 muscles in a single subject among 12 examiners (6 experienced
with MUNIX, 6 less experienced) and to determine variables associated with variability
of measurements.
Methods
Twelve raters applied MUNIX in six different muscles (abductor pollicis brevis (APB),
abductor digiti minimi (ADM), biceps brachii (BB), tibialis anterior (TA), extensor dig. brevis
(EDB), abductor hallucis (AH)) twice in one single volunteer on consecutive days. All raters
visited at least one training course prior to measurements. Intra- and inter-rater variability as
determined by the coefficient of variation (COV) between different raters and their levels of
experience with MUNIX were compared.
Results
Mean intra-rater COV of MUNIX was 14.0% (±6.4) ranging from 5.8 (APB) to 30.3% (EDB).
Mean inter-rater COV was 18.1 (±5.4) ranging from 8.0 (BB) to 31.7 (AH). No significant differences
of variability between experienced and less experienced raters were detected.
Conclusion
We provide evidence that quality control for neurophysiological methods can be performed
with similar standards as in laboratory medicine. Intra- and inter-rater variability of MUNIX is
muscle-dependent and mainly below 20%. Experienced neurophysiologists can easily
adopt MUNIX and adequate teaching ensures reliable utilization of this method
Evaluation of real-life outcome data of patients with spinal muscular atrophy treated with nusinersen in Switzerland.
Spinal muscular atrophy (SMA) is an autosomal recessive disorder causing progressive proximal muscular, respiratory, and bulbar weakness. We present outcome data on motor function, ventilation, nutrition, and language development of SMA patients treated with nusinersen in Switzerland. This multicenter, observational study included 44 patients. At treatment initiation, after 2 months and then every 4 months we assessed motor function with the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND), Hammersmith Functional Motor Scale expanded (HFMSE) and 6-Minute Walk Test (6MWT). At treatment initiation, patients were 0.1-44.6 years old, treatment duration ranged from 6 to 41 months. All 11 SMA type 1 children achieved higher CHOP-INTEND scores at the last assessment compared to treatment initiation, 4 acquired stable sitting. Six type 1 children were <18 months-old at treatment initiation. Two of them did not need ventilation or nutritional support at the last assessment; three had delayed language development and 3 articulation difficulties. 5/21 SMA type 2 patients achieved higher HFMSE scores. All ambulant type 3 patients showed a gain in the 6MWT. Nusinersen is an effective treatment, with gains in motor function occurring particularly in children and SMA type 1, but also in type 2 and 3, adolescents and adults
Evaluation of real-life outcome data of patients with spinal muscular atrophy treated with nusinersen in Switzerland
Spinal muscular atrophy (SMA) is an autosomal recessive disorder causing progressive proximal muscular, respiratory, and bulbar weakness. We present outcome data on motor function, ventilation, nutrition, and language development of SMA patients treated with nusinersen in Switzerland. This multicenter, observational study included 44 patients. At treatment initiation, after 2 months and then every 4 months we assessed motor function with the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND), Hammersmith Functional Motor Scale expanded (HFMSE) and 6-Minute Walk Test (6MWT). At treatment initiation, patients were 0.1-44.6 years old, treatment duration ranged from 6 to 41 months. All 11 SMA type 1 children achieved higher CHOP-INTEND scores at the last assessment compared to treatment initiation, 4 acquired stable sitting. Six type 1 children were <18 months-old at treatment initiation. Two of them did not need ventilation or nutritional support at the last assessment; three had delayed language development and 3 articulation difficulties. 5/21 SMA type 2 patients achieved higher HFMSE scores. All ambulant type 3 patients showed a gain in the 6MWT. Nusinersen is an effective treatment, with gains in motor function occurring particularly in children and SMA type 1, but also in type 2 and 3, adolescents and adults
Old World megadroughts and pluvials during the Common Era
Climate model projections suggest widespread drying in the Mediterranean Basin and wetting in Fennoscandia in the coming decades largely as a consequence of greenhouse gas forcing of climate. To place these and other “Old World” climate projections into historical perspective based on more complete estimates of natural hydroclimatic variability, we have developed the “Old World Drought Atlas” (OWDA), a set of year-to-year maps of tree-ring reconstructed summer wetness and dryness over Europe and the Mediterranean Basin during the Common Era. The OWDA matches historical accounts of severe drought and wetness with a spatial completeness not previously available. In addition, megadroughts reconstructed over north-central Europe in the 11th and mid-15th centuries reinforce other evidence from North America and Asia that droughts were more severe, extensive, and prolonged over Northern Hemisphere land areas before the 20th century, with an inadequate understanding of their causes. The OWDA provides new data to determine the causes of Old World drought and wetness and attribute past climate variability to forced and/or internal variability
Improvements in walking distance during nusinersen treatment: a prospective 3-year SMArtCARE Registry Study
A source of entangled photons based on a cavity-enhanced and strain-tuned GaAs quantum dot
A quantum-light source that delivers photons with a high brightness and a
high degree of entanglement is fundamental for the development of efficient
entanglement-based quantum-key distribution systems. Among all possible
candidates, epitaxial quantum dots are currently emerging as one of the
brightest sources of highly entangled photons. However, the optimization of
both brightness and entanglement currently requires different technologies that
are difficult to combine in a scalable manner. In this work, we overcome this
challenge by developing a novel device consisting of a quantum dot embedded in
a circular Bragg resonator, in turn, integrated onto a micromachined
piezoelectric actuator. The resonator engineers the light-matter interaction to
empower extraction efficiencies up to 0.69(4). Simultaneously, the actuator
manipulates strain fields that tune the quantum dot for the generation of
entangled photons with fidelities up to 0.96(1). This hybrid technology has the
potential to overcome the limitations of the key rates that plague current
approaches to entanglement-based quantum key distribution and
entanglement-based quantum networks. Introductio
Reply: Adult-onset distal spinal muscular atrophy: a new phenotype associated with KIF5A mutations
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