15,118 research outputs found
Disruption of the developmental programme of Trypanosoma brucei by genetic ablation of TbZFP1, a differentiation-enriched CCCH protein
No full textThe regulation of differentiation is particularly important in microbial eukaryotes that inhabit multiple environments. The parasite Trypanosoma brucei is an extreme example of this, requiring exquisite gene regulation during transmission from mammals to the tsetse fly vector. Unusually, trypanosomes rely almost exclusively on post-transcriptional mechanisms for regulated gene expression. Hence, RNA binding proteins are potentially of great significance in controlling stage-regulated processes. We have previously identified TbZFP1 as a trypanosome molecule transiently enriched during differentiation to tsetse midgut procyclic forms. This small protein (101 amino acids) contains the unusual CCCH zinc finger, an RNA binding motif. Here, we show that genetic ablation of TbZFP1 compromises repositioning of the mitochondrial genome, a specific event in the strictly regulated differentiation programme. Despite this, other events that occur both before and after this remain intact. Significantly, this phenotype correlates with the TbZFP1 expression profile during differentiation. This is the first genetic disruption of a developmental regulator in T. brucei. It demonstrates that programmed events in parasite development can be uncoupled at the molecular level. It also further supports the importance of CCCH proteins in key aspects of trypanosome cell function
A finger mechanism for adaptive end effectors
No full textThis paper presents design and analysis of a rigid link finger, which may be suitable for a number of adaptive end effectors. The design has evolved from an industrial need for a tele-operated system to be used in nuclear environments. The end effector is designed to assist repair work in nuclear reactors during retrieval operation, particularly for the purpose of grasping objects of various shape, size and mass. The work is based on the University of Southampton's Whole Arm Manipulator, which has a special design consideration for safety and flexibility. The paper discusses kinematic issues associated with the finger design, and to the end of the paper specifies the limits of finger operating parameters for implementing control law
Risks of occupational exposures to hand-transmitted vibration: VIBRISKS
No full textVIBRISKS seeks to improve understanding of the risk of injury from hand-transmitted vibration and whole-body vibration by means of epidemiological studies supported by fundamental laboratory
research. VIBRISKS is a consortium of six partners from six European countries (France, Germany, Italy, Sweden, The Netherlands, UK). The four-year research project, which commenced in 2003, involves three work packages devoted to hand-transmitted vibration and three work packages devoted to whole-body vibration. This paper summarizes the hand-transmitted vibration research. Work package 1 defines methods to be used in studies of disorders caused by hand-transmitted
vibration in work package 2 and integrates the results of the epidemiological studies in work package 2 with the results of experimental and modeling studies in WP3 so as to define procedures that can be applied by occupational health workers for minimizing risk, screening exposed individuals and managing individuals with symptoms. Work package 2 involves longitudinal studies in workers
exposed to hand-transmitted vibration. Work package 3 involves experimental studies of the acute effects of hand-transmitted vibration on vascular and neurological function and the development of a finite element model of the biodynamic responses of the finger to vibration and force
Countries and the global rate of soil erosion
No full textSoil erosion is a major threat to food security and ecosystem viability, as current rates are orders of magnitude higher than natural soil formation. Governments around the world are trying to address the issue of soil erosion. However, we do not know whether countries have much actual control over their soil erosion. Here, we use a high-resolution, global dataset with over 35 million observations and a spatial regression discontinuity design to identify how much of the global rate of soil erosion is actually affected by countries and which country characteristics, including their policies, are associated with this. Overall, moving just across the border from one country to the next, the rate of soil erosion changes on average by ~1.4 t ha−1 yr−1, which reveals a surprisingly large country effect. The best explanation we find is countries’ agricultural characteristics
The architecture of zinc finger domains containing R proteins.
No full text<p>The scale (0–1300) represents the size of proteins and their domains. The position and number of zinc finger domains in each <i>R</i> genes are also represented in the scale. The black broken lines indicate the zinc finger domains in individual R-proteins.</p
R-Code: Generation of SPEI data and estimation of drought effects on feed prices in South Germany
No full textWe provide
here the R-code for the complete replication of
Schaub and Finger (2019a). The code allows to i) download weather data
from the German Meteorological Office, ii) extract weather information for the
agricultural area of Germany, iii) compute the Standardized Precipitation
Evapotranspiration Index (SPEI), iv) to estimate an SVAR model and v) to replicate
figures and tables presented in Schaub and Finger (2019a). The code is
structured into 1) a master file (‘r_master_script_feed_price_paper.R’), 2) a
file for weather data preparation (‘r_weather_script_feed_price_paper.R’) and
3) a file for data preparation, estimation and visualization of results
(‘r_estimation_script_feed_price_paper.R’). Please follow instructions in the
master file when executing the code. The data for the replication can be found
at Schaub and Finger (2019b).</p
Aliphatic index profile of identified zinc finger domain across cloned <i>R</i> gene.
No full text<p>The data of 26 zinc finger <i>R</i> genes with their zinc finger types were included in this analysis.</p
Instability index profile of identified zinc finger domain across cloned <i>R</i> gene.
No full text<p>The data of 26 zinc finger <i>R</i> genes with their zinc finger types were included in this analysis.</p
Summary of various Zinc finger domains present in cloned <i>R</i> genes.
No full text<p>Summary of various Zinc finger domains present in cloned <i>R</i> genes.</p
Quantifying the soil erosion legacy of the Soviet Union
No full textWe examine the historical legacy of the Soviet Union on the current rate of human-induced soil erosion in its successor countries. We use a spatial regression discontinuity design and high-resolution soil erosion data. Our results suggest strong discontinuities in current soil erosion rates along the former border of the Soviet Union. We find that soil erosion in countries that were part of the former Soviet Union is 26% lower than in neighboring countries (0.77 tons per hectare and year). In contrast, we do not find such discontinuity in potential soil erosion under natural vegetation, underlining that this effect is man-made. We show that the main mechanism is a sharp discontinuity in forest dynamics, whereas general economic and demographic differences are less important
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