Non-genomic regulation of intermediate conductance potassium channels by aldosterone in human colonic crypt cells

BACKGROUND: Aldosterone has a rapid, non-genomic, inhibitory effect on macroscopic basolateral K+ conductance in the human colon, reducing its capacity for Cl− secretion. The molecular identity of the K+ channels constituting this aldosterone inhibitable K+ conductance is unclear. AIM: To characterise the K+ channel inhibited by aldosterone present in the basolateral membrane of human colonic crypt cells. METHODS: Crypts were isolated from biopsies of healthy sigmoid colon obtained during colonoscopy. The effect of aldosterone on basolateral K+ channels, and the possible involvement of Na+:H+ exchange, were studied by patch clamp techniques. Total RNA from isolated crypts was subjected to reverse transcriptase-polymerase chain reaction (RT-PCR) using primers specific to intermediate conductance K+ channels (KCNN4) previously identified in other human tissues. RESULTS: In cell attached patches, 1 nmol/l aldosterone significantly decreased the activity of intermediate conductance (27 pS) K+ channels by 31%, 53%, and 54% after 1, 5 and 10, minutes, respectively. Increasing aldosterone concentration to 10 nmol/l produced a further 56% decrease in channel activity after five minutes. Aldosterone 1–10 nmol/l had no effect on channel activity in the presence of 20 µmol/l ethylisopropylamiloride, an inhibitor of Na+:H+ exchange. RT-PCR identified KCNN4 mRNA, which is likely to encode the 27 pS K+ channel inhibited by aldosterone. CONCLUSION: Intermediate conductance K+ channels (KCNN4) present in the basolateral membranes of human colonic crypt cells are a target for the non-genomic inhibitory effect of aldosterone, which involves stimulation of Na+:H+ exchange, thereby reducing the capacity of the colon for Cl− secretion

The Committee on Lands of the Conservation Commission, Canada, 1909-1921: Romantic Agrarianism in Ontario in an Age of Agricultural Realism

The Conservation Commission of Canada (CCC) was formed in 1909 as an advisory body to Liberal Prime Minister Wilfrid Laurier. It was divided into eight committees, each of which dealt with the management of a specific natural resource. The Committee on Lands (CL) was composed of members who were unable to accept or understand the changes in contemporary agriculture as it moved into the twentieth century. Dr. James Robertson, chair of the CL, was a staunch agrarian romantic, who believed that the most important attribute of agriculture was the moral, individual and spiritual benefit which it conveyed to the individual. The recommendations and projects of the CL were inappropriate and often outdated and redundant. Their endeavours were noted and appreciated by farmers, but their work had no lasting effect on agriculture in Ontario. The official concept of 'conservation', defined by the CCC, was based on efficient management of Canadian natural resources, including the soil. In reality, the CL interpreted conservation to mean the preservation of a vanishing rural lifestyle.La Commission de Conservation du Canada (CCC) a été créée en 1909 pour agir comme organe aviseur auprès du premier ministre libéral Wilfrid Laurier. Au nombre de ses huit comités chargés chacun de la gestion d’une ressource naturelle spécifique, le Comité sur les terres (CT) était composé de membres incapables d’accepter ou de comprendre les changements auxquels était confrontée l’agriculture à l’aube du vingtième siècle. Le Dr. James Robertson, président du CT, était un romantique fidèle aux valeurs de la terre, convaincu des bénéfices moraux, individuels et spirituels qu’elle apportait. Les recommandations et projets du CT étaient souvent inappropriés, mal adaptés à leur époque ou redondants. Les efforts de ses membres furent appréciés par les fermiers, mais leur travail n’a eu aucun effet durable sur l’agriculture ontarienne. Le concept officiel de « conservation », tel que défini par la CCC, se fondait sur la gestion efficace des ressources naturelles canadiennes, incluant la terre, mais fut en fait interprété par le CT comme un moyen de préserver le mode de vie agricole en voie de disparition

A study to develop improved spacecraft show survey methods using Skylab/EREP data: Demonstration of the utility of the S190 and S192 data

The author has identified the following significant results. This interim report provides a demonstration of the utility of spacecraft acquired Skylab S190A and S190B photography and S192 imagery for mapping areal extent of snow cover in western United States test site areas. The data sample is from the SL-2 mission flown in June 1973. Results of the investigation indicate that areal snow cover extent can be mapped more accurately from the S190A and S190B photography than from any other spacecraft system, including ERTS. The results of a qualitative analysis of the S192 imagery indicate considerable potential for the utility of multispectral snow cover analysis; the potential for distinguishing snow from clouds automatically is particularly significant

The application of Heat Capacity Mapping Mission (HCMM) thermal data to snow hydrology

The application of HCMM thermal infrared data to snow hydrology and the prediction of snowmelt runoff was evaluated. Data for the Salt Verde watershed in central Arizona and the southern Sierra Nevada in California were analyzed and compared to LANDSAT and NOAA satellite data, U-2 thermal data, and other correlative data. It was determined that HCMM thermal imagery provides data as accurate for snow mapping as does visible imagery, and that in comparison with the reslution of other satellite imagery, it may be the most useful. Data from the HCMM thermal channel, with careful calibration, provides useful snow surface temperature data for hydrological purposes. An approach to an automated method of analysis is presented

〔研究ノート〕Curriculum, Collaboration, and Coaching: A Multi-Faceted Approach to Study Abroad Preparation

The American College Readiness Track was created as part of an intensive English study abroad program in order to prepare female Japanese students for matriculation at universities that use English as the medium of instruction. This paper describes the specific goals of this academic track and the development of its curriculum using a backward design approach. The paper also explains the process used in selecting faculty to teach in the track, the professional development activities organized to prepare those faculty members for their assignments, and the ways in which the faculty collaborated to further develop and improve the track. In addition, the paper discusses the introduction of coaching into the American College Readiness Track. Coaching is defined, and its benefits are described. Cultural considerations, for example, the reinforcement of hierarchy inherent in the Japanese language and Japanese students' relative reticence in the classroom environment are also discussed in relation to their impact on the coaching process.departmental bulletin pape

Investigation of mesoscale cloud features viewed by LANDSAT

The author has identified the following significant results. Some 50 LANDSAT images displaying mesoscale cloud features were analyzed. This analysis was based on the Rayleigh-Kuettner model describing the formation of that type of mesoscale cloud feature. This model lends itself to computation of the average wind speed in northerly flow from the dimensions of the cloud band configurations measured from a LANDSAT image. In nearly every case, necessary conditions of a curved wind profile and orientation of the cloud streets within 20 degrees of the direction of the mean wind in the convective layer were met. Verification of the results by direct observation was hampered, however, by the incompatibility of the resolution of conventional rawinsonde observations with the scale of the banded cloud patterns measured from LANDSAT data. Comparison seems to be somewhat better in northerly flows than in southerly flows, with the largest discrepancies in wind speed being within 8m/sec, or a factor of two

The application of ERTS imagery to monitoring arctic sea ice: Supplemental report

There are no author-identified significant results in this report

The use of LANDSAT data to study mesoscale cloud features

There are no author-identified significant results in this report

Ideal Bose gas in fractal dimensions and superfluid 4^4He in porous media

Physical properties of ideal Bose gas with the fractal dimensionality between D=2 and D=3 are theoretically investigated. Calculation shows that the characteristic features of the specific heat and the superfluid density of ideal Bose gas in fractal dimensions are strikingly similar to those of superfluid Helium-4 in porous media. This result indicates that the geometrical factor is dominant over mutual interactions in determining physical properties of Helium-4 in porous media.Comment: 13 pages, 6 figure