Stomatal control of leaf fluxes of carbonyl sulfide and CO₂ in a <i>Typha</i> freshwater marsh

Carbonyl sulfide (COS) is an emerging tracer to constrain land photosynthesis at canopy to global scales, because leaf COS and CO2 uptake processes are linked through stomatal diffusion. The COS tracer approach requires knowledge of the concentration normalized ratio of COS uptake to photosynthesis, commonly known as the leaf relative uptake (LRU). LRU is known to increase under low light, but the environmental controls over LRU variability in the field are poorly understood due to scant leaf scale observations.Here we present the first direct observations of LRU responses to environmental variables in the field. We measured leaf COS and CO2 fluxes at a freshwater marsh in summer 2013. Daytime leaf COS and CO2 uptake showed similar peaks in the mid-morning and late afternoon separated by a prolonged midday depression, highlighting the common stomatal control on diffusion. At night, in contrast to CO2, COS uptake continued, indicating partially open stomata. LRU ratios showed a clear relationship with photosynthetically active radiation (PAR), converging to 1.0 at high PAR, while increasing sharply at low PAR. Daytime integrated LRU (calculated from daytime mean COS and CO2 uptake) ranged from 1 to 1.5, with a mean of 1.2 across the campaign, significantly lower than the previously reported laboratory mean value (∼ 1.6). Our results indicate two major determinants of LRU – light and vapor deficit. Light is the primary driver of LRU because CO2 assimilation capacity increases with light, while COS consumption capacity does not. Superimposed upon the light response is a secondary effect that high vapor deficit further reduces LRU, causing LRU minima to occur in the afternoon, not at noon. The partial stomatal closure induced by high vapor deficit suppresses COS uptake more strongly than CO2 uptake because stomatal resistance is a more dominant component in the total resistance of COS. Using stomatal conductance estimates, we show that LRU variability can be explained in terms of different patterns of stomatal vs. internal limitations on COS and CO2 uptake. Our findings illustrate the stomata-driven coupling of COS and CO2 uptake during the most photosynthetically active period in the field and provide an in situ characterization of LRU – a key parameter required for the use of COS as a photosynthetic tracer

Intuitiver und rationaler kognitiver Stil bei der Personalauswahl

Personnel selection has been criticised by scientific researchers for its intuitive interpersonal perception (e.g. Guion, 1998, Obermann, 2002 etc.). Despite extensive scientific research in organizational setting (Mell, 1988; Schuler, 2001 etc.), Human Resource practitioners attribute their successful decisions to intuition (Nowicki & Rosse, 2002). In the Studies 1 to 4, personnel decisions made by the participants with different cognitive styles were tested. Participants were asked to select the best candidate based on his resume and recommendations (Study 1). The candidates had to be evaluated after the structured interview (Study 2) or after the group discussion during the Assessment Center (Study 4). Participants also had the possibility to decide using the scores of the candidates achieved during the Assessment Center (Study 3). The results of the first four studies revealed that the intuitive cognitive style was very successful in situations when working with information (e.g. scores, resumes). This finding supports opinions of the organizational practitioners (Agor, 1989 etc.). At the same time, intuitive interpersonal judgment (e.g. observation) was significantly worse than rational. This finding supports the recommendations of organizational psychologists to use standardized methods (e.g. personality tests and structured interviews). One explanation of these findings is that intuitive participants have a higher confirmation-bias than rational participants, which was found to influence negatively successful decision making (e.g. Kray & Galinski, 2003). Intuitive participants showed higher confirmation bias than rational participants, especially in the step-by-step procedure. Rational articipants were interested in the controversial information, but not when asked to decide spontaneously. Alternative explanation of these considers the learning style preferences of the intuitive and rational participants. Rational participants tend to use Realistic Observation, which might explain their good observer qualities. Intuitive participants tend to use Active Experimentation and might handle data with ease, in comparison to the rational participants. Studies 3 and 4 continued investigation on the intuitive and rational decision making in different stages of the personnel selection. Intuitive decision makers were found to be better when handling with big amounts of partially missing, irrelevant information or handling scores of the standardized procedures. They also had higher preferences for cognitive bias and selecting the recommendations supporting their opinion then opposite to it. This could be explained by their learning style preferences – active and pragmatic. Looking for new things and implementing findings. Rational decision makers were more theoretical and looking for controversial information, except for the situations when under stress or forced to make a decision. In this case, similar to the intuitive participants, they also tend to search for consistent information. In the Study 5, we have measured the performance evaluation of groups with rational and intuitive cognitive styles, as well as heterogeneous groups. The findings supported the results of the previous studies (e.g. Armstrong & Priola, 2001) that intuitive groups are more successful when working in the natural conditions. Intuitive members come along with each other and don’t report difficulties even when working in the virtual environment. Heterogeneous groups reported no difficulties in the mutual work or communication with each other. In sum, we have studied the influence of the intuitive and rational style on the personnel decisions made when using different personnel selection methods (application screening, employment interview, Assessment Center, recommendations). We have also studied the mutual work of the participants with different cognitive styles

The Use of Monograms on Byzantine Seals in the Early Middle-Ages (6th to 9th Centuries)

The paper deals especially with monograms on Byzantine lead seals. The early form was the block monogram, a type used already in Classical times, which came into fashion in the Byzantine world in the 6th or already in the 5th century and remained important till the early 7th century. Such monograms hide normally a name, a title or an office, the Greek ones in genitive, the Latin ones in nominative or genitive. Many of them can be read in different ways. For the double using of parts of letters for other ones the well-known Latin monogram of Theoderich is explained in detail. But the “typical Byzantine monogram” became the cross monogram, with letters more or less affixed on the arms of a Greek cross. The earliest example stems from a coin of Justinus I, starting 522, quite earlier than Theodora’s monograms on capitals in the Hagia Sophia. These cruciform monograms presented in the beginning also a name, a title or an office, but in the 8th century already often a combination of them; these monograms with prosopographical information stopped in Byzantium at the end of the 8th century. On the other hand invocative monograms (like Θεοτόκε βοήθει), often with the tetragram τῷ σῷ δούλῳ in the free quarters of the monogram, started around the middle of the 7th century and can be found till the earlier 11th century. The most common ones were collected by V. Laurent – we use this system till today, though there are much more types documented. An important problem is that sometimes single letters are “hidden” in another letter, e. g. Lambda in Alpha or Delta, Epsilon in a Kappa on the left bar of a cross monogram, Sigma in Epsilon, Sigma in Kappa, Omikron in Rho, etc.In Vienna we developed a special program to solve many monograms. If we bring all the readable letters of a monogram (including the possibly additional ones) in an alphabetical order, and do the same with the letters of names, titles and offices which were used in this time, both categories can be combined without problems. Sometimes even modest combinations of letters can be interpreted in many ways – e.g. with usual and very rare names; but who could forbid someone with a rare name to produce a monogram for himself

Force sensing glove for quantification of joint torques during stretching after spinal cord injury in the rat model.

An increasing amount of healthcare resources is used for the treatment and prevention of contractures in patients with spinal cord injury (SCI), with stretch and passive movements remaining the most prominent intervention methods. The results of both clinical trials and animal studies in recent years have shown traditional stretch therapies to be ineffective at preventing contracture and joint immobility, and have encouraged further emphasis on evidence-based practices. However, these studies only analyzed one aspect of stretching, dosage, and failed to look at the characteristic of joint torque. Recent clinical trials have unearthed the fact that the joint torque application of therapeutic stretches in the clinic not only vary by therapist, but also can be well beyond the range of torques tolerated by able-bodied individuals. A glove device utilizing force sensing resistors (FSRs) was developed to gauge joint torques. Coupled with a custom National Instruments’ LabVIEW program, the device was able to accurately measure forces, and eventually torques, applied during stretching. This study sought to explain what range of torques were being applied during stretching after SCI in the rat model in the hopes of understanding how to administer safe, effective therapeutic stretches. Six adult female Sprague-Dawley rats were mildly contused at T9 using the NYU impactor device with a 12.5 g-cm weight drop. n=2 rats were stretched 2 days per week and n=2 rats were stretched once per week using an eight minute protocol, for the first 5 weeks post-injury while controls (n=2) received no stretch therapy. Briefly, the tibialis anterior (TA) and triceps surae (TS) muscle groups were stretched by two therapists bilaterally for a minute each, totaling 4 minutes of stretch per rat per day. Kinematic assessments of stretching were accompanied by force measurement data and were used to generate comparisons between therapeutic torque and end range of motion (ROM) of the ankle. The data suggests that both once and twice per week stretching regimens were not enough to inhibit locomotor recovery or elicit a noticeable change in end ROM in such a mild injury model. There were noticeable differences in torques applied during stretching by different therapists, confirming the findings of previous studies. More importantly, the data showed that immediately after injury the normal end ROM can be achieved by applying less torque. The torque necessary to reach the end ROM increases to baseline values by week 5, potentially due to a return of the stretch reflex during spinal shock. This study urges other aspects of stretching therapy to be considered and suggests a tool for therapists to quantitatively apply safe and consistent stretching therapies to patients