Does acclimation in distinct light conditions determine differences in the photosynthetic heat tolerance of coffee plants?

Worldwide coffee production is threatened by climate change, which highlights the importance of heat tolerance studies. Here we tested the hypothesis that photosynthetic heat tolerance in coffee varieties changes according to acclimation to distinct light conditions. Furthermore, we tested if heat tolerance is associated with the habitat of origin of the coffee species. We evaluated heat tolerance using chlorophyll fluorescence in varieties of Coffea arabica (Mundo Novo and Catuai Amarelo) and C. canephora (Conilon) grown in a common garden under two conditions: high (HS) and low (LS) sunlight. Leaf traits associated with leaf cooling were evaluated in plants grown in LS and HS and associations of heat tolerance with these traits were determined. The varieties tested had high photosynthetic heat tolerance, with temperatures above 54 °C leading to a 50% reduction in Fv /Fm (T50 ). The heat tolerance of each Coffea variety was unaffected by growth in distinct light conditions. Leaves of plants grown in LS were larger and had a lower fraction of the leaf area occupied by stomata (nast ). Heat tolerance was positively associated with leaf size and negatively with nast . C. canephora exhibited higher heat tolerance than C. arabica. The limited plasticity of heat tolerance in response to acclimation under distinct light conditions contradicts the prediction that plants acclimated to HS would have higher photosynthetic heat tolerance than those acclimated to LS. Our results on heat tolerance among Coffea species/varieties in HS and LS indicate the possibility of selection of varieties for better acclimation to ongoing climate changes.

Study of in situ adsorption kinetics of polyelectrolytes and liposomes using quartz crystal microbalance: Influence of experimental layout.

Quartz Crystal Microbalance (QCM) is a widely used technique to characterize adsorption/desorption phenomena at the solid/liquid interface. However, the obtained adsorption/desorption kinetics curves are often not reproducible and present some noise and long term fluctuations. In this work, the accuracy of a commercial QCM to measure the adsorbed amount of polyelectrolytes and biological molecules was evaluated in terms of experimental QCM configurations with respect to quality, stability, and reproducibility of the measured data. Evaluation consisted in comparing the adsorption kinetics curves of the cationic polyelectrolyte poly(ethyleneimine) and the anionic 1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (sodium salt) liposomes, when setting the quartz crystal surface in stationary horizontal open, stationary horizontal closed, stationary vertical open, continuous vertical closed, and stationary vertical closed measuring configuration. For this last configuration, a new cell was designed and implemented. The analysis of the kinetics curves revealed that horizontal modes are more unstable when subjected to fostering noise due to the mechanical vibrations and lead to resonance frequency shift. This shift is caused by the measurement of non-adsorbed molecules which are deposited on the quartz crystal due to gravity force. The vertical modes proved to be more reproducible and reliable.

Domestic water uses: characterization of daily cycles in the north region of Portugal.

Nowadays, there is an increasing discussion among specialists about water use efficiency and the best measures to improve it. In Portugal, there have been a few attempts to expand the implementation of in situ water reuse projects. However, there is a lack of information about indoor water uses and how they are influenced by sociodemographic characteristics. There are several studies that investigate per capita global water usage, but the partitioning of this volume per domestic device and daily cycles is yet unknown. Identified as one of the key questions in sustainable building design, the water end-use is of primary importance to the design of hydraulic networks in buildings. In order to overcome this lack, a quantitative characterization of daily water uses for each domestic device was performed, based on a weekly monitoring program in fifty-two different dwellings in the northern region of Portugal (Vila Real, Valpaços and Oporto). For forty of them, each water usage of different domestic devices of each dwelling was recorded. At the same time, the remaining twelve dwellings were also monitored in order to register the volume of water consumed in each utilization of each domestic device. This paper presents the results of this complete monitoring program, using collected data to establish indoor water use patterns for each domestic device, aiming to support a more realistic approach to residential water use. The daily cycles in the different cities, where the monitoring program was performed, are also presented, in order to evaluate possible influences of sociodemographic characteristics.

Impact of liver ex situ transection on pediatric liver transplantation.

UNLABELLED: Ex situ hepatic transection (ESHT) has allowed transplantation of younger and smaller patients than whole liver grafts. Liver transection is a technical challenge due to the prolonged back table time, possible graft lesions, and increased surgical bleeding from the cut surface. We compare the outcomes of whole versus transected liver grafts in pediatric liver transplantation. METHODS: We retrospectively studied 41 pediatric patients who underwent 42 consecutive liver transplants (1 retransplant) from cadaveric donors. The study included all patients <18 years old who were transplanted at our institution from December 2001 to September 2009. Patients were distributed into 2 groups: whole organ (WO; n = 20) and transected liver grafts (TLG; n = 21). The ESHT grafts included 17 splits and 5 reduced size livers. We evaluated the age, weight, blood component transfusions, 1-year survival, laboratory tests at 2nd and 7th days postoperatively, surgical complications, reoperations, rejection episodes, cold ischemia time, biliary reconstruction type, and donor laboratory tests. Data were analyzed using Fisher and Student's t-tests. RESULTS: The mean age was 115 months (range, 7 months to 17.6 years) in the WO group and 43.3 months (range, 5 months to 16.25 years) in the TLG group (P = .0003). Mean weight was 19.8 kg (range, 5.8-67) and 9.7 Kg (range, 5.2-57) in the WO and TLG groups, respectively (P = .0079). Red blood cell transfusion was higher in the TLG group (P = .0479). Laboratory tests showed no difference between the 2 groups considering hepatic lesions or function markers. One-year patient survivals were 90% and 85.8% among the WO and LTG, respectively (P = .588). The overall 1-year survival rate was 88.8%. CONCLUSION: ESHT allowed smaller and younger children to be transplanted. There was an increased necessity of red blood cell transfusions after hepatic transection. There was no impact on liver function or 1-year patient or graft survival after ESHT.

Preparo do 99mTc - DTPA para estudos de cintilografia renal / 99mTc DTPA for renal scintilography studies

O objetivo deste trabalho foi preparar, em condiçöes adequadas, o fármaco (DTPA) marcado com isótopo radioativo para estudos de cinrilografia renal. Além de avaliar a funçäo renal, este fármaco permite diagnosticar, precocemente, alteraçöes que indicam rejeiçäo de tecido, em casos de transplante de rins. Inicialmente, foram realizados experimentos com camundongos para investigar a distribuiçäo biológica do radiofármaco. Os resultados mostraram que, alguns minutos após a administraçäo, os rins apresentavam uma captaçäo de radioatividade. Estes dados e os resultados dos testes de esterilidade, apirogenicidade e pureza radioquímica confirmaram a qualidade do radiofármaco, permitindo o seu emprego em cintilografias de pacientes com comprometimento renal