Open Letter to Science Teachers

A wise choice of emphasis was made in 1932 when the Junior Academy of Science was organized and supported by the Iowa Academy of Science. All activities involved secondary teachers and students. Activities included science club, community-service projects, individual and group science projects, essays, and an annual meeting in conjunction with the Iowa Academy of Science

The Iowa Junior Academy of Science

The Iowa Junior Academy of Science was organized in 1931 as a group of 15 high school science clubs of state to promote and reward student scientific endeavors. The Junior Academy offered the opportunity communications between students and teacher-sponsors from different localities

Linkages between soil carbon, soil fertility and nitrogen fixation in Acacia senegal plantations of varying age in Sudan

Background: Over the last decades sub-Saharan Africa has experienced severe land degradation and food security challenges linked to loss of soil fertility and soil organic matter (SOM), recurrent drought and increasing population. Although primary production in drylands is strictly limited by water availability, nutrient deficiencies, particularly of nitrogen (N) and phosphorus (P), are also considered limiting factors for plant growth. It is known that SOM (often measured as soil organic carbon (SOC)) is a key indicator of soil fertility, therefore, management practices that increase SOM contents, such as increasing tree cover, can be expected to improve soil fertility. The objectives of this study were to investigate the effect of Acacia senegal (Senegalia senegal) trees on soil nitrogen, phosphorus and potassium (K) in relation to SOC, the potential of A. senegal for N-2 fixation, and to identify possible N and P ecosystem limitations. Methods: Soil nutrient (total N, P, K and available P and exchangeable K) concentrations and stocks were determined for the 0-10,10-20,20-30 and 30-50 cm layers of A. senegal plantations of varying age (ranging from 7 to 24-years-old) and adjacent grasslands (reference) at two sites in semi-arid areas of Sudan. At both sites, three plots were established in each grassland and plantation. The potential of A. senegal for N-2 fixation in relation to plantations age was assessed using delta N-15 isotopic abundances and nutrient limitations assessed using C:N:P stoichiometry. Results: Soil concentrations of all studied nutrients were relatively low but were significantly and directly correlated to SOC concentrations. SOC and nutrient concentrations were the highest in the topsoil (0-10 cm) and increased with plantations age. Acacia foliage delta N-15 values were >6%o and varied little with plantations age. Soil C:N and C:P ratios did not differ between grassland and plantations and only 0-10 cm layer N:P ratios showed significant differences between grassland and plantations. Discussion: The results indicated that soil fertility in the Sahel region is strongly related to SOM contents and therefore highlighting the importance of trees in the landscape. The higher mineral nutrient concentrations in the topsoil of the plantations may be an indication of 'nutrient uplift' by the deeper roots. The high foliar delta N-15 values indicated that N(2 )fixation was not an important contributor to soil N contents in the plantations. The accretion of soil N cannot be explained by deposition but may be related to inputs of excreted N brought into the area annually by grazing and browsing animals. The soil C:N:P stoichiometry indicated that the plantations may be limited by P and the grasslands limited by N.Peer reviewe

Effect of Carbon Dioxide on the Twinkling Artifact in Ultrasound Imaging of Kidney Stones: A Pilot Study

Bone demineralization, dehydration and stasis put astronauts at increased risk of forming kidney stones in space. The color-Doppler ultrasound "twinkling artifact," which highlights kidney stones with color, can make stones readily detectable with ultrasound; however, our previous results suggest twinkling is caused by microbubbles on the stone surface which could be affected by the elevated levels of carbon dioxide found on space vehicles. Four pigs were implanted with kidney stones and imaged with ultrasound while the anesthetic carrier gas oscillated between oxygen and air containing 0.8% carbon dioxide. On exposure of the pigs to 0.8% carbon dioxide, twinkling was significantly reduced after 9-25 min and recovered when the carrier gas returned to oxygen. These trends repeated when pigs were again exposed to 0.8% carbon dioxide followed by oxygen. The reduction of twinkling caused by exposure to elevated carbon dioxide may make kidney stone detection with twinkling difficult in current space vehicles

Help! Help Your Substitute Teach Science

The science teacher often finds that to miss a day of school most frequently means to have lost a day of instruction. School administrators are experiencing serious difficulty in finding substitutes for teachers of the new B.S.C.S., C.B.A., CHEMS and P.S.S.C., programs

Collaborative SCA Survival Project: Cardiac Arrest Survival is a Mess

Systems diagnoses have been effectively used to understand many complex organizational systems within healthcare, government, military, and global corporate enterprises. Systems methodologies have been effectively used to change the direction and improve the outcomes of complex organizational systems. We feel that framing cardiac arrest survival as a systems problem and applying a systems methodology is innovative, practical, and essential if we are to make significant and sustainable impact

Test of cold denaturation mechanism for proteins as a function of water's structure

In a recent paper [PRL 91, 138103 (2003)] a new mechanism to explain the cold denaturation of proteins, based on the loss of local low-density water structure, has been proposed. In the present paper this mechanism is tested by means of full atom numerical simulations. In good agreement with this proposal, cold denaturation resulting in the unfolded state was found at the High Density Liquid (HDL) state of water, at which the amount of open tetragonal hydrogen bonds decreases at cooling.Comment: 5 pages, 5 figure

Making the great transformation, November 13, 14, and 15, 2003

This repository item contains a single issue of the Pardee Conference Series, a publication series that began publishing in 2006 by the Boston University Frederick S. Pardee Center for the Study of the Longer-Range Future. This Conference took place during November 13, 14, and 15, 2003. Co-organized by Cutler Cleveland and Adil Najam.The conference discussants and participants analyze why transitions happen, and why they matter. Transitions are those wide-ranging changes in human organization and well being that can be convincingly attributed to a concerted set of choices that make the world that was significantly and recognizably different from the world that becomes. Transition scholars argue that that history does not just stumble along a pre-determined path, but that human ingenuity and entrepreneurship have the ability to fundamentally alter its direction. However, our ability to ‘will’ such transitions remains in doubt. These doubts cannot be removed until we have a better understanding of how transitions work