Using the TIMS to estimate evapotranspiration from a forest

The main goals were: (1) to characterize the evapotranspiration (Et) of two forested watersheds using direct measurement techniques, and (2) to evaluate if remotely sensed surface temperatures could be used to estimate Et from the same watersheds. Two independent approaches for estimating the Et from watersheds were used. The first was derived using the Penman-Monteith Equation. This model requires the direct measurement of the microclimate of the site as well as biological measurements, i.e., stomatal conductance to water vapor and the leaf area of the stand. The primary limitation of this approach is that the measurement of stomatal conductance is time consuming, and in large trees, access to the foliage is difficult so the sample must be limited to the small number of trees. In the study, the sample was limited to the trees which could be measured from a single tower in each stand

A Mariotte-based verification system for heat-based sap flow sensors

Determination of the accuracy of commonly used techniques for measuring sap flux density in trees often presents a challenge. We therefore designed and built a verification system for heat-based sap flow sensors typically used at stem level. In the laboratory, a Mariotte's bottle device was used to maintain a constant flow rate of water through freshly cut stem segments of American beech (Fagus grandifolia Ehrh.). This verification system was used to determine the accuracy of three heat-based sap flux density techniques: heat pulse velocity, thermal dissipation and heat field deformation. All three techniques substantially underestimated sap flux density when compared against gravimetric measurements. On average the actual sap flux density was underestimated by 35% using heat pulse velocity, 46% using heat field deformation and 60% using thermal dissipation. These differences were consistent across sap flux densities ranging from 5 to 80 cm(3) cm(-2) h(-1). Field measurements supported the relative sensor performance observed in the laboratory. Applying a sensor-specific correction factor based on the laboratory test to the field data produced similar estimates of sap flux density from all three techniques. We concluded that a species-specific calibration is therefore necessary when using any of these techniques to insure that accurate estimates of sap flux density are obtained, at least until a physical basis for error correction can be proposed

Expression Of The Proto-oncogene C-fos Following Electrical Kindling In The Rat

Kindling is an example of permanent change in brain function that results from repeated elicitation of epileptiform neural activity. The molecular/genetic mechanisms by which kindling is produced and maintained are just beginning to be addressed. Recently two proto-oncogenes, c-fos and c-Ha-ras, have been identified as possible mediators of intracellular signal transduction and may mediate the kindling process. Additionally, c-fos, has been proposed as the gene responsible for turning on molecular events that might underlie the long-term neural changes that occur during kindling. The objective of the present study was to: (i) further investigate the enhancement of c-fos and c-Ha-ras levels following kindled seizures and (ii) investigate the role of c-fos in the plastic changes underlying kindling.;In this study, male hooded rats, were electrically kindled and the resulting c-fos and c-Ha-ras gene expression was quantified using Northern blot analysis. The results indicated that: (i) c-fos was constitutively expressed in forebrain and cerebellum, (ii) basal levels of c-fos were equivalent in naive and in fully kindled rats that has been seizure free for 3 weeks, (iii) an amygdala-pyriform kindled seizure massively and transiently increased c-fos levels, (iv) kindled seizure enhancement of c-fos was observed throughout forebrain and cerebellum, (v) enhancement of AD duration corresponded to enhanced c-fos levels, (vi) enhanced c-fos levels were observed in the amygdala-pyriform contralateral to the kindled site, and the enhancement did not depend on the occurrence of Ad in the contralateral amygdala-pyriform, (vii) electrical stimulations not resulting in AD increased c-fos levels, (viii) c-fos levels were increased by control stimulation, (ix) c-fos induction was partially refractory, (x) PTZ caused c-fos induction independent of a motor convulsion, and (xi) kindled seizures did not alter the expression of c-Ha-ras.;The most parsimonious explanation that accounts for the observations made in this study is that c-fos was expressed simply as a consequence of neural activity and not exclusively due to the specific neural activity (afterdischarge) required for kindling

Combining stressors that individually impede long-term memory blocks all memory processes

The effects of stress on memory are typically assessed individually; however, in reality different stressors are often experienced simultaneously. Here we determined the effect that two environmentally relevant stressors, crowding and low calcium availability, have on memory and neural activity following operant conditioning of aerial respiration in the pond snail, Lymnaea stagnalis. We measured aerial breathing behaviour and activity of a neuron necessary for memory formation, right pedal dorsal 1 (RPeD1), in the central pattern generator (CPG) that drives aerial respiration in untrained animals, and assessed how these traits changed following training. In naïve animals both crowding and combined stressors significantly depressed burst activity in RPeD1 which correlated with a depression in aerial breathing behaviour, whereas low calcium availability had no effect on RPeD1 activity. Following training, changes in burst activity in RPeD1 correlated with behavioural changes, decreasing relative to their naïve state at 3 h and 24 h in control conditions when both intermediate-term memory (ITM: 3 h) and long-term memory (LTM: 24 h) are formed, at 3 h but not 24 h when exposed to individual stressors when only ITM is formed, and did not change in combined stressors (i.e. when no memory is formed). Additionally, we also found that Lymnaea formed short-term memory (STM: 10 min) in the presence of individual stressors or under control conditions, but failed to do so in the presence of combined stressors. Our data demonstrate that by combining stressors that individually block LTM only we can block all memory processes. Therefore the effects of two stressors with similar individual affects on memory phenotype may be additive when experienced in combination

ANNOTATIONS AND PERFORMANCE SUGGESTIONS FOR SELECTED EXCERPTS FROM MARCEL MOYSE'S TONE DEVELOPMENT THROUGH INTERPRETATION

In 1919 Marcel Moyse secured the position of Principle Flutist of the Opera Comiqueorchestra in Paris. It was during his stay with the orchestra that he was inspired to compile a collection of operatic and other melodies to aid flutists in their quest for a "good tone." The result is Tone Development Through Interpretation for the Flute (and other wind instruments): The study of expression, vibrao, color, suppleness and their application to different styles (published by McGinnis and Marx publishers in 1962, with a corrected edition appearing in 1978). Tone Development Through Interpretation (TDTI) contains 90 excerpts (transcribed for flute) from works by 28 composers. Ten excerpts are from instrumental works by composers such as Handel, Mozart, Beethoven, and Wagner. Two excerpts are from folk songs (one French and one Japanese). Seventy-eight excerpts are from opera arias by Bellini, Bizet, Delibes, Donizetti, Gounod, Massenet, Messager, Offenbach, Rossini, &middot;Saint-Saens, Verdi and Weber. Also included with the work are piano accompaniments for nine of the excerpts. These were added to the corrected edition of 1978.</p

Environmentally relevant stressors alter memory formation in the pond snail Lymnaea

Stress alters adaptive behaviours such as learning and memory. Stressors can either enhance or diminish learning, memory formation and/or memory recall. We focus attention here on how environmentally relevant stressors alter learning, memory and forgetting in the pond snail, Lymnaea stagnalis. Operant conditioning of aerial respiration causes associative learning that may lead to long-term memory (LTM) formation. However, individual ecologically relevant stressors, combinations of stressors, and bio-active substances can alter whether or not learning occurs or memory forms. While the behavioural memory phenotype may be similar as a result of exposure to different stressors, how each stressor alters memory formation may occur differently. In addition, when a combination of stressors are presented it is difficult to predict ahead of time what the outcome will be regarding memory formation. Thus, how combinations of stressors act is an emergent property of how the snail perceives the stressors.</jats:p