A new method for restoring ditches in peatlands: ditch filling with fiber bales

Ditching is a common practice to dewater wetlands, including peatlands, and ditch blocking is a common method for restoring wetlands because substrate is often unavailable for filling the ditches. However, filling has many advantages compared to blocking ditches. Our goal was to test whether ditches could be filled in a Colorado sloping fen (Chattanooga Fen) using bales created from shredded aspen (Populus tremuloides) tree‐fiber. We monitored water table levels before and after we filled two ditches (combined length of approximately 165 m × 3 m wide) as well as an undisturbed reference portion of Chattanooga fen. The reference site had stable water tables that rarely dropped more than 20 cm below the soil surface. The ditches had been dewatering large areas of the fen for at least 100 years. Filling the ditches with fiber bales resulted in a water table increase between 2 and 22 cm in an area up to 150 m below the ditch. Native sedges now cover the area where we filled the ditches, with no erosion or compression/settling of the ground observed and no water backing up behind the filled ditches. Filling the ditches with shredded fiber bales is a good option for restoration in wilderness areas, or areas lacking peat or mineral soil fill because it is a natural material that is easily transported and placed in the ditches.     

Tastants evoke cAMP signal in taste buds that is independent of calcium signaling

We previously showed that rat taste buds express several adenylyl cyclases (ACs) of which only AC8 is known to be stimulated by Ca²⁺. Here we demonstrate by direct measurements of cAMP levels that AC activity in taste buds is stimulated by treatments that elevate intracellular Ca²⁺. Specifically, 5 µM thapsigargin or 3 µM A-23187 (calcium ionophore), both of which increase intracellular Ca²⁺ concentration ([Ca²⁺]_i), lead to a significant elevation of cAMP levels. This calcium stimulation of AC activity requires extracellular Ca²⁺, suggesting that it is dependent on Ca²⁺ entry rather than release from stores. With immunofluorescence microscopy, we show that the calcium-stimulated AC8 is principally expressed in taste cells that also express phospholipase C₂ (i.e., cells that elevate [Ca²⁺]_i in response to sweet, bitter, or umami stimuli). Taste transduction for sucrose is known to result in an elevation of both cAMP and calcium in taste buds. Thus we tested whether the cAMP increase in response to sucrose is a downstream consequence of calcium elevation. Even under conditions of depletion of stored and extracellular calcium, the cAMP response to sucrose stimulation persists in taste cells. The cAMP signal in response to monosodium glutamate stimulation is similarly unperturbed by calcium depletion. Our results suggest that tastant-evoked cAMP signals are not simply a secondary consequence of calcium modulation. Instead, cAMP and released Ca²⁺ may represent independent second messenger signals downstream of taste receptors. calcium-sensitive adenylyl cyclase; capacitative entry; cross talk; taste transduction     

An anatomical model to determine step height in step testing for estimating aerobic capacity

Physical fitness has been reported to be inversely related to coronary heart disease and other health related problems. One of the most valid means of assessing physical fitness is the test of aerobic capacity. Aerobic capacity is the greatest rate at which the body can consume oxygen and represents the most efficient integration of the various physiological processes which make up the oxygen transport system. However, direct measurement of aerobic capacity requires sophisticated laboratory equipment, and is adversive to subjects. Step tests are widely used to estimate aerobic capacity. Because the biomechanical efficiency and work rate is determined by step height, accommodation of step height to the subject's statute height should provide a better estimation of aerobic capacity. A hip angle of 73.3 degrees, when stepping, was found to give the best relationship of recovery heart rate of a step test to direct measurement of aerobic capacity. Using 73.3 degrees, the following equations were developed for determining the stepping height when using the step test: Hf = 0.189 Ih and Hf = 0.192 Ih for females and males respectively, where hf is the step height and Ih is the statute height of the subject. A correlation coefficient (r) of 0.93 was calculated between various hip angles and calculated foot height of 182 observations of 47 females while a correlation coefficient (r) of 0.96 was calculated from 208 observations of 53 males. Using these equations to determine step height, measurement of 30 females showed a mean hip angle of 73.3 degrees +/- 2.2 and measurement of 30 males showed a mean hip angle of 73.3 degrees +/- 2.1.(ABSTRACT TRUNCATED AT 250 WORDS)     

Identification of Dirofilaria immitis larval antigens with immunoprophylactic potential using sera from immune dogs.

Previous research has demonstrated that dogs that received chemically abbreviated Dirofilaria immitis larval infections were significantly immune to challenge infections. Sera from those immune animals have been effective in passively transferring larval killing and stunting. In the present study, sera from immune and control animals were used to screen various Ag subsets for unique Ag. Through Western blot analysis of larval extracts and excretory-secretory products, and immunoprecipitation of metabolically labeled proteins and larval surface Ag, it was determined that as many as 12 molecules were uniquely recognized by protective immune sera. A 39-kDa molecule was present in both soluble lysates of third- and fourth-stage larvae and larval excretory-secretory products; it was recognized by each of the immune dogs and by none of the infected or uninfected control animals. The 39-kDa molecule appeared to be absent from adults and microfilariae of the parasite. In addition to the unique recognition by immune dog sera, larval stage specificity of this molecule suggests that it may be useful as a vaccine candidate.     

Diagnosis and antibiotic treatment of acute otitis media: report from International Primary Care Network.

STUDY OBJECTIVE--The relation between a history of disorders suggestive of acute otitis media, symptoms, and findings of an examination of the tympanic membrane and doctors'' certainty of diagnosis. Also, to examine differences in prescribing habits for acute otitis media among doctors from different countries. DESIGN--Questionnaires were completed by participating doctors for a maximum of 15 consecutive patients presenting with presumed acute otitis media. SETTING--General practices in Australia, Belgium, Great Britain, Israel, The Netherlands, New Zealand, Canada, Switzerland, and the United States. PATIENTS--3660 Children divided into the three age groups 0-12 months, 13-30 months, and greater than or equal to 31 months. MAIN OUTCOME MEASURES--General practitioners'' responses to questions on their diagnostic certainty and resolution of patients'' symptoms after two months. RESULTS--The diagnostic certainty in patients aged 0-12 months was 58.0%. This increased to 66.0% in those aged 13-30 months and 73.3% in those aged greater than or equal to 31 months. In all age groups diagnostic certainty was positively associated with the finding of a tympanic membrane that was discharging pus or bulging. Redness of the membrane and pain were also associated with certainty in patients aged 13-30 months, and a history of decreased hearing or recent upper respiratory infection was positively associated in patients aged greater than or equal to 31 months. The proportion of patients prescribed antibiotics varied greatly among the countries, from 31.2% in The Netherlands to 98.2% in both Australia and New Zealand, as did the duration of treatment. Patients who did not take antibiotics had a higher rate of recovery than those who did; the rate of recovery did not differ between different types of antibiotic. CONCLUSIONS--Doctors'' certainty of diagnosis of acute otitis media was linked to patient''s age. Improved criteria or techniques for diagnosing acute otitis media, especially in very young children, need to be developed. Antibiotic treatment did not improve the rate of recovery of patients in this study.