Senescence and protein degradation in leaf segments of young winter wheat: influence of leaf age

Leaf senescence in intact wheat plants can be strongly influenced by altered source/sink relations. Interactions with other plant parts are no longer possible in detached leaves and therefore differences in their senescence behaviour reflect the physiological status of the leaf before cutting. The net degradation of chlorophylls and of selected enzyme proteins (detected by SDS-PAGE and immunoblotting) was delayed in detached young leaves as compared to senescing or mature leaves excised from the same field-grown wheat plants. The physiological leaf age was therefore decisive for the velocity of artificial senescence. Net degradation rates of the enzymes investigated varied in detached leaves. The protein quantities of plastidial glutamine synthetase, phosphoribulokinase and phosphoglycolate phosphatase decreased more rapidly than those of ferredoxin-dependent glutamate synthase and nitrite reductase. Differences were also detected between two enzymes involved in the same metabolic pathway (photorespiratory carbon cycle) but located in different subcellular compartments: the plastidial enzyme phosphoglycolate phosphatase was lost more rapidly than glycolate oxidase (peroxisomal enzyme

Glacial/interglacial changes in mineral dust and sea-salt records in polar ice cores: sources, transport, and deposition

Sea salt and mineral dust records as represented by Na+ and Ca2+ concentrations, respectively, in Greenland and Antarctic ice cores show pronounced glacial/interglacial variations. For the Last Glacial Maximum (LGM) mineral dust (sea salt) concentrations in Greenland show an increase of a factor of approximately 80 (15) compared to the Holocene and significant shifts by a factor of 15 (5) during Dansgaard Oeschger events. In Antarctica, the dust (sea salt) flux is enhanced by a factor of 15 (3) during the LGM compared to the Holocene and variations by approximately a factor of 8 (1-2) exist in parallel to Antarctic warm events. Primary glacial dust sources are the Asian deserts for Greenland and Patagonia for Antarctica. Ice core evidence and model results show that both changes in source strength as well as atmospheric transport and lifetime contributed to the observed changes in Greenland ice cores. In Antarctica changes in ice core fluxes are in large parts related to source variations both for sea salt and dust, where the formation of sea salt aerosol from sea ice may play a pivotal role. Summarizing our latest estimates on changes in sources, transport and deposition these processes are roughly able to explain the glacial increase in sea salt in both polar regions while they fall short by at least a factor of 4-7 for mineral dust. Future improvements in model resolution and in the formulation of source and transport processes together with new ice core records, e.g. on dust size distributions, will eventually allow to converge models and observations

Uncrossed cortico-muscular projections in humans are abundant to facial muscles of the upper and lower face, but may differ between sexes

Abstract : It is a popular concept in clinical neurology that muscles of the lower face receive predominantly crossed cortico-bulbar motor input, whereas muscles of the upper face receive additional ipsilateral, uncrossed input. To test this notion, we used focal transcranial magnetic brain stimulation to quantify crossed and uncrossed cortico-muscular projections to 6 different facial muscles (right and left Mm. frontalis, nasalis, and orbicularis oris) in 36 healthy right-handed volunteers (15 men, 21 women, mean age 25 years). Uncrossed input was present in 78% to 92% of the 6 examined muscles. The mean uncrossed: crossed response amplitude ratios were 0.74/0.65 in right/left frontalis, 0.73/0.59 in nasalis, and 0.54/0.71 in orbicularis oris; ANOVA p>0.05). Judged by the sizes of motor evoked potentials, the cortical representation of the 3 muscles was similar. The amount of uncrossed projections was different between men and women, since men had stronger left-to-left projections and women stronger right-to-right projections. We conclude that the amount of uncrossed pyramidal projections is not different for muscles of the upper from those of the lower face. The clinical observation that frontal muscles are often spared in central facial palsies must, therefore, be explained differently. Moreover, gender specific lateralization phenomena may not only be present for higher level behavioural functions, but may also affect simple systems on a lower level of motor hierarch

The PIP peptide of INFLORESCENCE DEFICIENT IN ABSCISSION enhances Populus leaf and Elaeis guineensis fruit abscission

The programmed loss of a plant organ is called abscission, which is an important cell separation process that occurs with different organs throughout the life of a plant. The use of floral organ abscission in Arabidopsis thaliana as a model has allowed greater understanding of the complexities of organ abscission, but whether the regulatory pathways are conserved throughout the plant kingdom and for all organ abscission types is unknown. One important pathway that has attracted much attention involves a peptide ligand-receptor signalling system that consists of the secreted peptide IDA (INFLORESCENCE DEFICIENT IN ABSCISSION) and at least two leucine-rich repeat (LRR) receptor-like kinases (RLK), HAESA (HAE) and HAESA-LIKE2 (HSL2). In the current study we examine the bioactive potential of IDA peptides in two different abscission processes, leaf abscission in Populus and ripe fruit abscission in oil palm, and find in both cases treatment with IDA peptides enhances cell separation and abscission of both organ types. Our results provide evidence to suggest that the IDA–HAE–HSL2 pathway is conserved and functions in these phylogenetically divergent dicot and monocot species during both leaf and fruit abscission, respectively

Central corneal thickness in spectral-domain OCT and associations with ocular and systemic parameters

Background. Optical coherence tomography (OCT) allows quantitative analysis of the anterior segment of the eye with a noncontact examination. The aim of this study is to analyze associations of central corneal thickness (CCT) as measured by OCT with ocular and systemic cardiovascular parameters. Methods. A cross-sectional study of 734 persons was performed in a working age population. Only healthy eyes were included. A comprehensive ophthalmological examination including refraction, noncontact tonometry, and imaging of the anterior segment by SD-OCT was performed. In parallel, a broad range of systemic cardiovascular parameters were measured. Associations were analyzed using a generalized estimating equations&#039; model. Results. CCT measurements showed a significant association with corneal curvature and intraocular pressure: a thinner CCT was associated with a flatter cornea and with lower intraocular pressure (p < 0.001). Age was positively associated with CCT (p < 0.001); all other cardiovascular parameters were not associated. Conclusion. A thinner cornea is associated with a flatter surface and with lower intraocular pressure readings, while there are no independent associations with refraction and systemic cardiovascular parameters. Our findings highlight the value of SD-OCT CCT measurements as a standard tool in anterior segment analysis

Semantically valid integration of development processes and toolchains

As an indispensable component of today’s world economy and an increasing success factor in production and other processes, as well as products, software needs to handle a growing number of specific requirements and influencing factors that are driven by globalization. Two common success factors in the domain of Software Systems Engineering are standardized software development processes and process-supported toolchains. Development processes should be formally integrated with toolchains. The sequence and the results of toolchains must also be validated with the specifications of the development process on several levels. The outcome of a conceptual deductive analysis is that there is neither a formal general mapping nor a generally accepted validation mechanism for the challenges that such an integrated concept faces. To close this research gap, this paper focuses on the core issue of the integration of development processes and toolchains in order to create benefits for modeling and automatization in the domain of systems engineering. Therefore, it describes a self-developed integration approach related to the recently introduced prototypical technical implementation TOPWATER. A unified metamodel specifies how processes and toolchains are linked by a general mapping mechanism that considers test options for the structural, content, and semantic levels

Leveraging lean in the office: Lean office needs a novel and differentiated approach

Lean Six Sigma tools have been increasingly employed also in the service industry, however with different success as field studies have shown. The reason not only has to be attributed to a poor Change Management, but can also be attributed to the intrinsic characteristics of the Lean techniques, which have been tailored to sustain a stable customer-takted pull-manufacturing principle. An office workplace shows significant differences to a procedural shop floor environment, as it comprises both, procedural and relational processes. The office environment, therefore, cannot be described by a purely transactional shop floor model—it necessitates a separate model, with a differenciated approach, which covers the procedural as well as the relational aspects of office tasks. Also the different characteristics of the transaction object as well as the operation transformation and process governance do not allow an un-adapted application of Toyota’s comprehensive Lean toolset. The approach of Lean for the office environment needs a reinterpretation of the Lean logic and TPS Lean tools for the procedural part as well. Therefore, different and adapted approaches and tools are clearly necessary. The paper shows the objectives and principles of Lean and why Lean manufacturing is also interesting to be applied in the office environment. The differences between office and production jobs are detailed and introduce the problem of lean application in the office. The particular characteristics of the office environment are discussed and enable to enter into the Relational Office Model. Furthermore, we explain the paradigm shift which is necessary to take full benefit of the Lean approach in the office environment, however without presenting the reinterpreted office Lean toolset due to space reasons. This will be the topic of a next paper.ISSN:1940-9893ISSN:1940-990

Low awareness of transient ischemic attacks and risk factors of stroke in a Swiss urban community

Background and purpose: Time delays from stroke onset to arrival at the hospital are the main obstacles for widespread use of thrombolysis. In order to decrease the delays, educational campaigns try to inform the general public how to act optimally in case of stroke. To determine the content of such a campaign, we assessed the stroke knowledge in our population. Methods: The stroke knowledge was studied by means of a closed-ended questionnaire. 422 randomly chosen inhabitants of Bern, Switzerland, were interviewed. Results: The knowledge of stroke warning signs (WS) was classified as good in 64.7%. A good knowledge of stroke risk factors (RF) was noted in 6.4%. 4.2% knew both the WS and the RF of stroke indicating a very good global knowledge of stroke. Only 8.3% recognized TIA as symptoms of stroke resolving within 24hours, and only 2.8% identified TIA as a disease requiring immediate medical help. In multivariate analysis being a woman, advancing age, and having an afflicted relative were associated with a good knowledge of WS (p=0.048, p<0.001 and p=0.043). Good knowledge of RF was related to university education (p<0.001). The good knowledge of TIA did not depend on age, sex, level of education or having an afflicted relative. Conclusions: The study brings to light relevant deficits of stroke knowledge in our population. A small number of participants could recognize TIA as stroke related symptoms resolving completely within 24hours. Only a third of the surveyed persons would seek immediate medical help in case of TIA. The information obtained will be used in the development of future educational campaign

Instruments and Methods: Direct measurement of sliding at the glacier bed

Sliding at the base of Trapridge Glacier, Yukon Territory, Canada, was measured using a “drag spool”. We describe this simple and inexpensive instrument as well as its installation and operation. From 1990 to 1992 seven sites were instrumented with drag spools. At six of the sites basal sliding, during the period of observation, accounted for 50-70% of the total flow observed at the glacier surface. The contribution from ice creep is known to be small, so most of the remaining surface motion must be attributed to subglacial sediment deformation. For the seventh site the observed sliding rate was ~ 90% of the total flow, an indication that the sliding contribution varies spatially across the bed. Diurnal variations in the response of one of our instruments appear to be correlated to subglacial water-pressure fluctuations and are interpreted in terms of changes in sliding velocity rather than the opening and closing of basal cavities