The role of metal ions in the electron transport through azurin-based junctions

We studied the coherent electron transport through metal–protein–metal junctions based on a blue copper azurin, in which the copper ion was replaced by three different metal ions (Co, Ni and Zn). Our results show that neither the protein structure nor the transmission at the Fermi level change significantly upon metal replacement. The discrepancy with previous experimental observations suggests that the transport mechanism taking place in these types of junctions is probably not fully coherent

IK-FA, a new heuristic inverse kinematics solver using firefly algorithm

In this paper, a heuristic method based on Firefly Algorithm is proposed for inverse kinematics problems in articulated robotics. The proposal is called, IK-FA. Solving inverse kinematics, IK, consists in finding a set of joint-positions allowing a specific point of the system to achieve a target position. In IK-FA, the Fireflies positions are assumed to be a possible solution for joints elementary motions. For a robotic system with a known forward kinematic model, IK-Fireflies, is used to generate iteratively a set of joint motions, then the forward kinematic model of the system is used to compute the relative Cartesian positions of a specific end-segment, and to compare it to the needed target position. This is a heuristic approach for solving inverse kinematics without computing the inverse model. IK-FA tends to minimize the distance to a target position, the fitness function could be established as the distance between the obtained forward positions and the desired one, it is subject to minimization. In this paper IK-FA is tested over a 3 links articulated planar system, the evaluation is based on statistical analysis of the convergence and the solution quality for 100 tests. The impact of key FA parameters is also investigated with a focus on the impact of the number of fireflies, the impact of the maximum iteration number and also the impact of (a, ß, ¿, d) parameters. For a given set of valuable parameters, the heuristic converges to a static fitness value within a fix maximum number of iterations. IK-FA has a fair convergence time, for the tested configuration, the average was about 2.3394 × 10-3 seconds with a position error fitness around 3.116 × 10-8 for 100 tests. The algorithm showed also evidence of robustness over the target position, since for all conducted tests with a random target position IK-FA achieved a solution with a position error lower or equal to 5.4722 × 10-9.Peer ReviewedPostprint (author's final draft

Effects of different culture conditions (photoautotrophic, photomixotrophic) and the auxin indole-butyric acid on the in vitro acclimatization of papaya (Carica papaya L. var. Red Maradol) plants using zeolite as support

Plant regeneration of papaya via organogenesis and somatic embryogenesis has been successful;  however, the biggest problem of in vitro culture of this species is the acclimatization of regenerated  plants, where over 70% of the plants are lost before being planted in the field. Decreasing the relative humidity inside the culture vessel and thus increasing the ventilation, appears to have a greater effect on  the adaptation of papaya plants, strengthening the function of the stomata and with this, allowing better  control of water loss from the leaves. The aim of this study was to determine the effects of different  concentrations of sucrose and indole-butyric acid (IBA) on rooting and in vitro acclimatization of plants  using sterile zeolite as support and culture vessels with increased ventilation. Three concentrations of  sucrose (0, 10 and 20 g L-1) were studied with and without auxin and as the control treatment, the  rooting culture medium with agar during 17, 27 and 37 culture days. The highest percentage of rooting  was recorded at 37 culture days in the treatment without sucrose and IBA with 80.0% and zeolite as  support. The best photosynthetic values were achieved when in vitro shoots were grown in culture  medium with auxin and different concentrations of sucrose, even though they were also high in the  treatment without the presence of IBA and without sucrose at 17 days of culture. The combined effect of the zeolite, auxin (IBA), without sucrose in the culture medium and increased ventilation allowed   photoautotrophic culture conditions which had effect of the increasing plant survival under ex vitro  acclimatization conditions.Key words: Carica papaya, photosynthesis, roots formation

Response of the photosynthetic apparatus to a flowering-inductive period by water stress in Citrus

The photosynthetic responses to a flowering-inductive water-stress period and recovery were studied and compared in two Citrus species. Under greenhouse conditions, Fino lemon and Owari satsuma trees were subjected to moderate (-2 MPa at predawn) and severe (-3 MPa) water stress levels and were re-watered after 60 days. Vegetative growth was inhibited during the stress assays, and strong defoliation levels were reported, especially in Fino lemon. In both species, bud sprouting was induced after re-watering. Flowers and vegetative shoots developed in Owari satsuma after a drought period, and the development was independent of the stress level. In Fino lemon, vegetative shoots and flowers were primarily formed after moderate and severe stress, respectively. The photosynthetic rate and stomatal conductance were reduced by water stress, and a marked increase in water-use efficiency at the moderate water deficit level was observed. Nevertheless, the photosynthetic apparatus was not damaged, since the maximum quantum yield, photosynthetic pigment concentrations and Rubisco level and activity did not change. Furthermore, the measured malonyldialdehyde (MDA) and peroxidase activity indicated that oxidative stress was not specifically triggered by water stress in our study. Therefore, the gas exchange, fluorescence and biochemical parameters suggested that diffusional limitations to photosynthesis predominated in both of the studied Citrus species, and explained the rapid recovery of the photosynthetic parameters after rehydration. The net CO 2 fixation rate and stomatal conductance were recovered within 24 h in Fino lemon, whereas 3 days were required in Owari satsuma. This suggests the presence of some metabolic limitations in the latter species. Furthermore, the sensibility of the defoliation rates, the accumulation of proline and the stomatal behaviour in response to water stress indicated a higher drought tolerance of Fino lemon, according to its better acclimation to hot climates. © 2011 Springer-Verlag.The authors thank Dr. J. Moreno and co-workers from the Departamento de Bioquimica of the Universidad de Valencia for his help and support in the Rubisco assays, and Dr. F. Fornes, Dr. A. Calatayud and Dr. E. Primo-Millo for the critical review of the manuscript. This work was funded by the Universitat Politecnica de Valencia, Spain (Ayudas para primeros proyectos de investigacion PAID06-06).Ávila Reséndiz, C.; Guardiola Barcena, JL.; González Nebauer, S. (2012). Response of the photosynthetic apparatus to a flowering-inductive period by water stress in Citrus. Trees - Structure and Function. 26(3):833-840. https://doi.org/10.1007/s00468-011-0657-4S833840263Addicott FT (1982) Abscission. 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Best Practices in Dengue Surveillance: A Report from the Asia-Pacific and Americas Dengue Prevention Boards

The Pediatric Dengue Vaccine Initiative organized Dengue Prevention Boards in the Asia-Pacific and the Americas regions consisting of dengue experts from endemic countries. Both Boards convened meetings to review issues in surveillance. Through presentations, facilitated discussions, and surveys, the Boards identified best practices in dengue surveillance including: (1) Dengue should be a notifiable disease in endemic countries; (2) World Health Organization regional case definitions should be consistently applied; (3) electronic reporting systems should be developed and used broadly to speed delivery of data to stakeholders; (4) minimum reporting should include incidence rates of dengue fever, dengue hemorrhagic fever, dengue shock syndrome, and dengue deaths, and hospitalization and mortality rates should be reported by age group; (5) periodic additional studies (e.g., capture/recapture) should be conducted to assess under-detection, under-reporting, and the quality of surveillance; (6) laboratory methods and protocols should be standardized; (7) national authorities should encourage laboratories to develop networks to share expertise and data; and (8) RT-PCR and virus isolation (and possibly detection of the NS1 protein) are the recommended methods for confirmation of an acute dengue infection, but are recommended only for the four days after onset of fever—after day 4, IgM-capture enzyme-linked immunosorbent assay is recommended

Clinical Impact of the COVID-19 Pandemic in Mexican Patients with Thoracic Malignancies

BACKGROUND: Accumulated evidence indicates that patients with lung cancer are a vulnerable population throughout the pandemic. Limited information is available in Latin America regarding the impact of the pandemic on medical care. The goal of this study was to describe the clinical and social effect of COVID-19 on patients with thoracic cancer and to ascertain outcomes in those with a confirmed diagnosis. MATERIALS AND METHODS: This cohort study included patients with thoracic neoplasms within a single institution between March 1, 2020, and February 28, 2021. All variables of interest were extracted from electronic medical records. During this period, the Depression Anxiety and Stress Scale 21 (DASS-2) was applied to evaluate and identify more common psychological disorders. RESULTS: The mean age for the total cohort (n = 548) was 61.5 ± 12.9 years; non-small cell lung cancer was the most frequent neoplasm (86.9%), advanced stages predominated (80%), and most patients were under active therapy (82.8%). Any change in treatment was reported in 23.9% of patients, of which 78.6% were due to the COVID-19 pandemic. Treatment delays (≥7 days) were the most frequent modifications in 41.9% of cases, followed by treatment suspension at 37.4%. Patients without treatment changes had a more prolonged progression-free survival and overall survival (hazard ratio [HR] 0.21, p < .001 and HR 0.28, p < .001, respectively). The mean DASS-21 score was 10.45 in 144 evaluated patients, with women being more affected than men (11.41 vs. 9.08, p < .001). Anxiety was reported in 30.5% of cases, followed by depression and distress in equal proportions (18%). Depressed and stressed patients had higher odds of experiencing delays in treatment than patients without depression (odds ratio [OR] 4.5, 95% confidence interval [CI] 1.53–13.23, p = .006 and OR 3.18, 95% CI 1.2–10.06, p = .006, respectively). CONCLUSION: Treatment adjustments in patients with thoracic malignancies often occurred to avoid COVID-19 contagion with detrimental effects on survival. Psychological disorders could have a role in adherence to the original treatment regimen

Uncoupling human and climate drivers of late Holocene vegetation change in southern Brazil

In the highlands of southern Brazil an anthropogenitcally driven expansion of forest occurred at the expense of grasslands between 1410 and 900cal BP, coincident with a period of demographic and cultural change in the region. Previous studies have debated the relative contributions of increasing wetter and warmer climate conditions and human landscape modifcations to forest expansion, but generally lacked high resoltiuon proxies to measure these efects, or have relied on single proxies to reconstruct both climate and vegetation. Here, we develop and test a model of natural ecosystem distribution against vegetation histories, paleoclimate proxies, and the archaeological record to distinguish human from temperature and precipitation impacts on the distribution and expansion of Araucaria forests during the late Holocene. Carbon isotopes from soil profles confrm that in spite of climatic fuctuations, vegetation was stable and forests were spatially limited to south-facing slopes in the absence of human inputs. In contrast, forest management strategies for the past 1400 years expanded this economically important forest beyond its natural geographic boundaries in areas of dense pre-Columbian occupation, suggesting that landscape modifcations were linked to demographic changes, the efects of which are still visible today