Tracheid length prediction in Pinus palustris by means of near infrared spectroscopy: the influence of age

The prediction of tracheid length using near infrared (NIR) wavelengths can provide either useful or misleading calibrations depending on the context. This can happen since tracheid length is not directly related to the absorbance at any wavelength but is instead the result of a secondary correlation with some unknown chemical constituent. In this work, the effect of tree age and height on NIR predictability was investigated since tracheid length and chemistry may vary as a function of location within the tree. It was found that tracheid length predictability did not change with height but decreased with age. As a result, predicting tracheid length regardless of age was good (R² = 0.72) while predictability holding age and height constant was mostly low to moderate with the exception of rings 1 and 4 which was quite strong.

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Vorhersage der Tracheidenlänge in Pinus palustris mittels NIR-Spektroskopie: Einfluss des Alters

Zusammenfassung Das Abschätzen der Tracheidenlänge mittels NIR-Spektroskopie kann je nach Sachlage zu brauchbaren oder auch irreführenden Kalibrierungen führen. Das kommt daher, dass die Tracheidenlänge nicht unmittelbar mit der Extinktion bei irgendeiner Wellenlänge in Beziehung steht, sondern über eine indirekte Korrelation mit unbekannten Inhaltsstoffen. In dieser Arbeit wird der Einfluss des Baumalters und der Höhe auf die Verlässlichkeit der NIR-Messung untersucht, da sowohl die Tracheidenlänge als auch die chemischen Bestandteile je nach Position im Baum varieren können. Es zeigte sich, dass die Vorhersagbarkeit der Tracheidenlänge sich nicht mit der Baumhöhe ändert, jedoch mit dem Alter abnimmt. Insgesamt war die Vorhersagbarkeit der Tracheidenlänge unabhängig vom Alter recht gut (R²=0,72); bei konstantem Baumalter und -höhe war sie jedoch mäßig bis niedrig außer für die Jahrringe 1 und 4, wo die Korrelation sehr streng war.

     

Analyzing the influence of median cross-section design on highway safety using vehicle dynamics simulations

Although vehicle dynamics simulations have long been used in vehicle design and crash reconstruction, their use for highway design is rare. This paper investigates the safety of highway medians through iterative simulations of off-road median encroachments. The commercially available software CarSim was used to simulate over one hundred thousand encroachments, representing the entire passenger vehicle fleet and a wide range of encroachment angles, departure speeds, steering inputs, and braking inputs. Each individual simulation output was then weighted using data from previous studies to reflect the probability of each specific accident scenario occurring in a real-life median encroachment. Results of this analysis illustrate the relative influence of median cross-section geometry on the resulting accident outcomes. The simulations indicate that the overall safety of a highway median depends on the occurrence of both vehicle rollover and median crossover events, and the cross-section shape, slope, and width are all shown to greatly affect each of these incidents. An evaluation of the simulation results was conducted with vehicle trajectories from previous experimental crash tests. Further assessment of the aggregate simulation results to actual crash data was achieved through comparison with several databases of crash statistics. Both efforts showed a strong agreement between the simulations and the real-life crash data.     

Comparison of glycosphingolipids and antibodies as receptor molecules for ricin detection

Glycosphingolipids (GSLs) have been shown to undergo strong interactions with a number of protein toxins, including potential bioterrorism agents such as ricin and botulinum neurotoxin. Characterization of this interaction in recent years has led to a number of studies where GSLs were used as the recognition molecules for biosensing applications. Here, we offer a comparison of quartz crystal microbalance (QCM) sensors for the detection of ricin using antibodies and the GSLs GM1 and asialoGM1, which have been shown to undergo strong interactions with ricin. The presence, orientation, and activity of the GSL and antibody films were confirmed using ellipsometry, Fourier transform infrared spectroscopy (FT-IR), and QCM. It was found that the GSLs offered more sensitive detection limits when directly compared with antibodies. Both GSLs had lower detection limits at 5 microg/mL, approximately 5 times lower than were found for antibodies (25 microg/mL), and their linear detection range extended to the highest concentrations tested (100 microg/mL), almost an order of magnitude beyond the saturation point for the antibody sensors. Potential sites for nonspecific adsorption were blocked using serum albumin without sacrificing toxin specificity.     

On-line processing of written text by younger and older adults.

Word-by-word reading times were measured for young and elderly adults who read single sentences for immediate recall. The reading strategies of young and old were similar in that both groups allocated time to process word-level and constituent-level features. Young and elderly readers differed mainly in how they allocated time for organizational processing: Whereas younger adults allocated extra processing time at sentence boundaries as well as at major and minor clause boundaries, older adults allocated extra time at major and minor clause boundaries only. Results were generally consistent with the notions that processes that are more microlevel (e.g., word access) become automatic with practice and that age deficits are minimal for such processes. Age differences in organization time allocated at clause boundaries, however, suggested age-related limitations in working memory processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exploiting smart antennas in wireless mesh networks using contention access

Smart antennas can increase the capacity of mesh networks and reduce the susceptibility of individual nodes to interception and jamming, but creating the conditions that allow them to be effective is difficult. In this article we provide a broad review of antenna technologies and identify their capabilities and limitations. We review mechanisms used by medium access control schemes to arbitrate access. These reviews let us identify a small set of conditions that are necessary for smart antenna exploitation. We then review the most common MAC approaches, carrier sense multiple access, slotted aloha, and time-division multiple access, and evaluate their suitability for exploiting smart antennas. We demonstrate that they are not capable of creating the complete set of antenna exploitation conditions while retaining a contention nature. We follow with a discussion of the synchronous collision resolution (SCR) MAC scheme and describe how it creates all the exploitation conditions. We conclude that SCR provides the best support for smart antenna exploitation with the added benefits that there is no requirement for all nodes to be equipped with the same antenna technologies and that smart antennas can be combined with channelization technologies to provide even higher capacities.     

Fast extraction of defect size distribution using a single layershort flow NEST structure

Defect inspection is required for process control and to enhance chip yield. Electrical measurements of test structures are commonly used to detect faults. To improve accuracy of electrically based determination of defect densities and defect size distributions, we present a novel NEST structure. There, many nested serpentine lines will be placed within a single layer only. This mask will be used as a short flow to guarantee a short turn around time for fast process data extraction. Data analysis procedures will provide densities and size distributions of killer defects that will have an impact on product chip yield     

Protein expression and enzymatic activities in normal and soft textured Atlantic salmon (Salmo salar) muscle

Soft textured Atlantic salmon is a sporadic and occasionally very severe problem for the farming and processing industries. The firm and soft fillets examined in this work differed in their gelatinase activities, cross-reactivity with anti-ubiquitin and anti-cathepsin L antibodies, as well as in the in-gel α-chymotryptic peptide maps of electrophoretically isolated myosin heavy chain (MHC) bands. The immunodetections of actin, α-actinin, MHC, and the MALDI TOF MS peptide mass fingerprinting of electrophoretically isolated MHCs only showed minor differences between samples. Other analyses revealed merely individual differences. These results seem to indicate a higher level of gelatinase activation, ubiquitination and cathepsin L cross-reacting material in softer muscle. These results would be consistent with a myopathy, but also with what could be expected in the skeletal muscle of healthy salmonid fish during a normal period of hyperplastic growth.     

Chemically isolated graphene nanoribbons reversibly formed in fluorographene using polymer nanowire masks

We demonstrated the fabrication of graphene nanoribbons (GNRs) as narrow as 35 nm created using scanning probe lithography to deposit a polymer mask(1-3) and then fluorinating the sample to isolate the masked graphene from the surrounding wide band gap fluorographene. The polymer protected the GNR from atmospheric adsorbates while the adjacent fluorographene stably p-doped the GNRs which had electron mobilities of ～2700 cm2/(V·s). Chemical isolation of the GNR enabled resetting the device to nearly pristine graphene.