Long-term water mass and redox potential dynamics in large weighable fen lysimeter

The water mass and redox potentials dynamics were intensively studied in peat soils. However, most of these studies were conducted either in the laboratory or in situ for the short-term period that does not reflect the actual long-term field conditions. Although sustainable management of peat soils needs to understand long-term water and redox potentials dynamics, there is little information on undisturbed peat soils. To address this problem, a large weighable fen lysimeter (LWFL) was installed at Lysimeter Station Falkenberg in 2003. The LWFL was filled with undisturbed 6 m3 (4 m length, 1 m width and 1.5 m depth) fen monolith. The lysimeter vessel had four electronic load cells at the four supporting points which are sensitive to detect and measure mass changes because of rain and evapotranspiration. Platinum redox electrodes were also horizontally installed in 20, 50 and 120 cm soil depth in three replications. The mass changes and redox potentials were automatically measured every hour interval for 13 years. The preliminary evaluation of the 13 years’ data showed that the mass change was strongly and positively associated with the rainfall distribution pattern. The lowest and highest annual masses were 7092 and 9768 kg that was recorded in 2009 and 2016, respectively. Both the average and individual years of monthly and daily mass changes were also the reflection of seasonal changes that affect the rainfall amount and distribution. However, the hourly mass change was not significant within a year, but among the most years. The change in redox potentials showed similar trends to that of the mass change but in the opposite directions. The redox potentials increased as mass decreased and vice versa. The results indicate that the lysimeter can be used to study long-term water and redox potentials dynamics to understand the biogeochemistry of peat soils

Knowledge, Attitude and Practice of Trained Traditional Birth Attendants on HIV/AIDS Prevention in Jimma Town, Southwest Ethiopia

Background: HIV/AIDS is a global pandemic with cases being reported from virtually every country in the world. There is a growing awareness in many African countries that trained traditional birth attendants have a major role to play in HIV/AIDS prevention. However, information on their knowledge, attitude and practice concerning prevention of the disease is scarce. Therefore, this study was designed to assess their knowledge, attitude and practice and document baseline data for the study area. Methods: A cross-sectional survey was conducted from October 25 to 30, 1999 on all the 30 trained traditional birth attendants serving in Jimma town in order to assess their knowledge, attitude and practice in the prevention of HIV/AIDS. A pre-tested, structured questionnaire was used to collect the data. Attitude was measured using a Likert scale. Results: All the 30 trained traditional birth attendants responded making a response rate of 100%. The study revealed that the majority, 17/30 (56.7%) were above the ages 50 years (mean +SD = 54 + 10), Christians, 19/30(63.3%), oromo, 11/36 (36.7%) and illiterate, 21/30(70%). It also showed that 70%, 80% and 70% of the study population had “good knowledge”, “favorable attitude” and “ safe practice”, respectively. However, 26.7% and 60% responded that shaking hands with AIDS patients and insect bite respectively were considered to be risky to transmit HIV infection by of the study population. Moreover, majority (60%) feels that AIDS patients should be isolated and 23.3 % reported to assist delivery bare handed. Health institutions and radio were reported to be the main sources of information on HIV/AIDS. Conclusion: Although majority of the study population does have good knowledge, favorable attitude and safe practice, there are some misconceptions on the modes of transmission of HIV/AIDS. Moreover, the majority is in favor of isolation of AIDS patients and some are practicing unsafely. Therefore, series of refreshment courses on the ways and means of HIV/AIDS transmission and prevention and safe delivery practices are recommended. Further large-scale study is also recommended.Ethiop J Health Sci Vol. 11, No. 2 July 200

Value chains, markets and economics: Africa RISING Science, Innovations and Technologies with Scaling Potential from the Ethiopian Highlands

United States Agency for International Developmen

Characterization of constricted fruit (ctf) Mutant Uncovers a Role for AtMYB117/LOF1 in Ovule and Fruit Development in Arabidopsis thaliana

Pistil and fruit morphogenesis is the result of a complex gene network that is not yet fully understood. A search for novel genes is needed to make a more comprehensive model of pistil and fruit development. Screening for mutants with alterations in fruit morphology generated by an activation tagging strategy resulted in the isolation of the ctf (constricted fruit) mutant. It is characterized by a) small and wrinkled fruits, with an enlarged replum, an amorphous structure of the septum and an irregular distribution of ovules and seeds; b) ectopic carpelloid structures in sepals bearing ovule-like structures and c) dwarf plants with curled rosette leaves. The overexpressed gene in ctf was AtMYB117, also named LOF1 (LATERAL ORGAN FUSION1). AtMYB117/LOF1 transcripts were localized in boundary regions of the vegetative shoot apical meristem and leaf primordia and in a group of cells in the adaxial base of petioles and bracts. Transcripts were also detected in the boundaries between each of the four floral whorls and during pistil development in the inner of the medial ridges, the placenta, the base of the ovule primordia, the epidermis of the developing septum and the outer cell layers of the ovule funiculi. Analysis of changes of expression of pistil-related genes in the ctf mutant showed an enhancement of SHATTERPROOF1 (SHP1) and SHP2 expression. All these results suggest that AtMYB117/LOF1 is recruited by a variety of developmental programs for the establishment of boundary regions, including the development of floral organs and the initiation of ovule outgrowth

Phosphorus dynamics in a tropical forest soil restored after strip mining

Background and aims We hypothesized that successful early ecosystem and soil development in these P-deficient soil materials will initially depend on effective re-establishment of P storage and cycling through organic matter. This hypothesis was tested in a 26-year chronosequence of seven lightly fertilized, oxidic soil materials restored to eucalypt forest communities after bauxite mining. Methods Total P (Pt) status, Hedley P fractions and partial chemical speciation (NaOH-EDTA extraction and analysed using solution 31P NMR spectroscopy) were determined in the restored soils. Results Concentrations of Pt and most Hedley fractions changed with restoration period, declined with depth and were strongly positively correlated with C and N concentrations. Biological P dominated the Labile and Intermediate P fractions while Long-term P was dominantly inorganic. Organic P concentrations in NaOH-EDTA extracts and their chemical natures were similar in restored and unburned native forest sites. Phosphomonoesters were the dominant class of organic P. Conclusions Surprisingly rapid P accretion and fractional changes occurred over 26 years, largely in the surface soils and closely associated with organic matter status. Alkaline hydrolysis products of phosphodiesters and pyrophosphate indicated the importance of microbial P cycling. The important consequences for long-term ecosystem development and biological diversity require further study

Subgroup Analysis via Recursive Partitioning

Subgroup analysis is an integral part of comparative analysis where assessing the treatment effect on a response is of central interest. Its goal is to determine the heterogeneity of the treatment effect across subpopulations. In this paper, we adapt the idea of recursive partitioning and introduce an interaction tree (IT) procedure to conduct subgroup analysis. The IT procedure automatically facilitates a number of objectively defined subgroups, in some of which the treatment effect is found prominent while in others the treatment has a negligible or even negative effect. The standard CART (Breiman et al., 1984) methodology is inherited to construct the tree structure. Also, in order to extract factors that contribute to the heterogeneity of the treatment effect, variable importance measure is made available via random forests of the interaction trees. Both simulated experiments and analysis of census wage data are presented for illustration.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000270824200001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Automation & Control SystemsComputer Science, Artificial IntelligenceSCI(E)EI38ARTICLE141-1581

Carbono do solo e atributos de fertilidade em resposta à calagem superficial em plantio direto

O objetivo deste trabalho foi avaliar o efeito da aplicação de calagem superficial sobre o conteúdo de carbono orgânico total (COT) do solo, em plantio direto, e identificar a relação entre esse conteúdo e outros atributos de fertilidade. O experimento foi realizado em Latossolo Vermelho de textura média, em Ponta Grossa, PR. Os tratamentos consistiram da aplicação de calcário dolomítico na superfície do solo, nas doses 0 e 6 Mg ha-1, em 1993, e da reaplicação de 0 e 3 Mg ha-1, em 2000, nas parcelas com e sem calcário. O solo foi coletado em 2008, e foram analisados os conteúdos de COT e os atributos de fertilidade. A calagem produziu aumento do conteúdo de COT e da saturação por bases, e diminuição da saturação por alumínio. O conteúdo de COT apresentou relação linear com a capacidade de troca catiônica (CTC) efetiva e correlação com os teores de P e K. A CTC potencial apresentou correlação com o COT, e a CTC efetiva com o pH. A calagem superficial em sistema plantio direto, em longo período, proporciona aumento no conteúdo de COT e de N total