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During the last quarter of 2019, the beaches, mangroves, and estuaries of Northeast Brazil received an unprecedented volume of crude oil from the sea, which became the worst environmental disaster ever to reach the Brazilian coast. The oil, having reached the shores completely unnoticed, left both society and government agents completely clueless on (i) where the oil was coming from; (ii) how much oil was still in the ocean to reach the shorelines; and (iii) which beaches were going to be affected next! By exploring remote sensing data and ocean numerical modeling, along with oil dispersion chemistry on sea water, this study investigates the possible origin and path of the spill and whether it could have been detected from space. The oil dispersion modeling simulations performed for this investigation revealed a possible region and timing of the oil spill, also indicating the likelihood of it being advected toward the shoreline under the ocean surface.

Takotsubo syndrome is found in about 5%–6% of patients presenting with suspected ST-elevation myocardial infarction. Coronary angiography with left ventriculography is currently considered the modality of choice for the diagnosis. However, improvements of noninvasive diagnostic techniques have been allowing for definite assessment of ventricular function and anatomy. In this setting, the combined use of coronary computed tomography angiography and cardiac magnetic resonance may play a pivotal role for a complete noninvasive diagnosis and management of these patients. We present a case of a 52-year-old woman who presented to our department complaining chest pain and showing left ventricular systolic dysfunction, electrocardiography abnormalities, and mild elevation of cardiac-specific serum enzymes.

The world’s forests are highly fragmented by linear disturbances, and many forests have failed to recover decades after abandonment. Lack of recovery is common in unproductive forests, such as treed peatlands, because of conditions that limit tree growth, including simplification of microtopography (loss of microsites). The persistence of these features affects biodiversity, but of particular concern in Canada is the detrimental effects on threatened woodland caribou. Although natural regeneration of trees in peatlands occurs in some places, it is not an effective recovery strategy for restoring the habitat of woodland caribou. This has led to restoration activities with costs exceeding CAD$12 500/km. However, current restoration does not consider wildfires, which can destroy planted trees but also initiate early seral conditions that favor natural regeneration. Here we compared tree regeneration on seismic lines and adjacent forest controls for burnt (75 sites) and unburnt (68 sites) treed peatlands in northeast Alberta, Canada. Tree regeneration (stems with a DBH < 1 cm/ha) varied from 28 500 in burnt lines, 11 440 in unburnt lines, and 18 210 in burnt forest, to 9520 in unburnt forest. Wildfires promoted denser regeneration in sites with a greater proportion of serotinous species and water table depth. Microtopography and terrain wetness explained regeneration on burnt lines, but not unburnt lines. In burnt and unburnt lines, sunlight, microtopography, and depth of water table most affected tree regeneration patterns.

The Covid-19 pandemic brought unprecedented challenges in the sector of Philippine education. The Department of Education Basic Education Learning Continuity Plan (BE-LCP) aims to ensure the continuity of learning thus, Pangasinan Division II implemented the Printed Modular Distance Learning (MDL) for the school year 2020-2021. The primary objective of this study is to understand the lived experiences of Science Teachers of Pangasinan Division II in the new normal setting of education. Using phenomenology, this study explored the challenges in adapting the new learning modality, the implementation of Most Essential Learning Competencies (MELCs), the production, distribution, and retrieval of self-learning modules (SLMs), the implementation of the interim guidelines in the grading system in the new normal education and the priority developmental plans and needs of Science teachers. From the data gathered through interview and analysis of the documents among twenty (20) Science teachers, it revealed that emerging themes capped into the acronym SURVIVORS which unfolds the Science teachers characteristics and experiences in the new face of education. The results showed that Science teachers are service-oriented, and the stakeholders showed unwavering support of stakeholders in the new learning modality. However, majority of the teachers exclaimed that distribution and retrieval of modules is the primary problem that arise from the different schools. Science teachers cope with these challenges through community partnerships and extending linkages that help them facilitate the distribution and retrieval of modules. In addition to that, Science teachers also acknowledged that printed modular learning should be shifted to blended learning as a modality in delivering education in the succeeding years. Integrating ICT through E-learning or online asynchronous learning could supplement the learners competencies alongside with the printed modules. Also, Science teachers have common priority development needs in terms of functional and core competencies. Lastly, it is notable that Science teachers should always be flexible and adaptive in their roles of as facilitators of education. &nbsp

Centrifugal pumps are used to transport fluids by the conversion of rotational kinetic energy to the hydrodynamic energy of the fluid flow. Since it is the most used pump in the world, then it must be improved now and then. The rotational energy typically comes from an engine or electric motor. This study was performed to investigate the effects of changing the number of impeller blades in the Head and the Efficiency of the pump running at constant and varying speeds. The researchers were able to provide a pump performance curve for 4, 5, 6, and 7 blades running at 2300 RPM, 2800 RPM, and 3300 RPM. It is shown in the results that utilizing the researcher’s centrifugal pump model with 7 impeller blades running at 3300 RPM is the most ideal and suitable operation.

Antimicrobial resistance is a challenging health problem that demands alternative treatments. Nanoplatforms with antimicrobial properties, associated with photodynamic and photothermal therapies, are potential candidates for this task due to characteristics such as non-invasive, antibiotic-free, dual selectivity, and low adverse effects in therapeutic procedures. Graphene quantum dots are a possible substitute for other nanoparticles, especially by presenting low toxicity and low cost. However, graphene quantum dot properties are highly dependent on the synthesis methods, which makes it difficult to compare and improve methods using different studies. In this work, we apply spectroscopic and photothermal methods to investigate a commercially available green fluorescent graphene quantum dot (GQD) as a potential antimicrobial agent and to determine its theranostics properties. The results showed that the photoactivation of the GQD in phosphate-buffered saline solution by light sources with wavelengths shorter than the emission band can generate singlet oxygen and a heat yield of [Formula: see text] under excitation at 532 nm, showing the potential of this GQD as a photodynamic and photothermal agent.

Networks of narrow linear (∼3–12 m wide) forest disturbances used for petroleum exploration (seismic lines) are common throughout Alberta’s boreal forest. These ‘seismic’ lines have often failed to recover trees decades after their initial disturbance, especially within treed peatland and jack pine (Pinus banksiana) forests. This has led to regional increases in forest fragmentation contributing to declines in threatened woodland caribou. Restoration of seismic lines to forests is now a top priority for conservation and recovery of woodland caribou, but are expensive and often ignore the occurrence of wildfires that may destroy restoration investments (planted trees), yet also recruit trees. This is especially relevant to jack pine forests that burn more frequently than other forests and depend on moderate to high intensity fires to release seeds en masse from their serotinous cones. Although much is known about jack pine tree recruitment following fire, little is known about patterns of tree recovery on seismic lines and how this varies with fire severity, line width (forest gap size), and line orientation. Here we examine natural tree recovery across a gradient in fire severity (defined as percent overstory tree mortality) with different seismic line characteristics (forest gap width and orientation), as compared to adjacent forest stands, in jack pine forests 5-years post-fire in northeast Alberta, Canada. Overall, jack pine regeneration was consistently 2-fold higher on seismic lines compared to adjacent burned forests with stem density increasing with fire severity in both sites, especially when fire severity was greater than 40%. We suggest that the observed increases in tree regeneration on seismic lines may be due to (1) removal of biomass and exposure of mineral soils on seismic lines creating more favorable conditions for jack pine seeds and seedlings; and/or (2) increases in available light resulting in better growing conditions and survival for this shade-intolerant species. Finally, we suggest that natural recovery (passive restoration) of seismic lines should be expected post-fire in jack pine stands and thus active restoration of these sites through silviculture and tree planting may not be the wisest use of limited restoration dollars if fires are locally common.

Restoring anthropogenic footprints to pre-disturbance conditions or minimizing their long-term impacts is an important goal in conservation. Many footprints, particularly if left alone, have wide-ranging effects on biodiversity. In Canada, energy exploration footprints result in forest dissection and fragmentation contributing to declines in woodland caribou. Developing cost effective strategies to restore forests and thus conserving the woodland caribou habitat is a conservation priority. In this study, we compared the effects of wildfire and local variation in the amount of residual woody debris on natural regeneration in jack pine on exploratory well pads in Alberta’s boreal forest. Specifically, we investigated how footprint size, fire severity (overstory tree mortality), ground cover of fine and coarse woody debris, and adjacent stand characteristics (i.e., height, age, and cover), affected tree regeneration densities and height using negative binomial count and linear models (Gaussian), respectively. Regeneration density was 30% higher on exploratory well pads than adjacent forests, increased linearly with fire severity on the exploratory well pads (2.2% per 1% increase in fire severity), but non-linearly in adjacent forests (peaking at 51,000 stems/ha at 72% fire severity), and decreased with amount of woody debris on exploratory well pads (2.7% per 1% increase in woody debris cover). The height of regenerating trees on exploratory well pads decreased with fire severity (0.56 cm per 1% increase in fire severity) and was non-linearly related to coarse woody debris (peaking at 286 cm at 9.4% coarse woody debris cover). Heights of 3 and 5 m on exploratory well pads were predicted by 13- and 21-years post-fire, respectively. Our results demonstrate that wildfires can stimulate natural recovery of fire-adapted species, such as jack pine, on disturbances as large as exploratory well pads (500–1330 m2) and that the type and amount of woody debris affects these patterns.

Ecological impacts of linear anthropogenic disturbances may be underestimated due to edge effects extending into adjacent forests. Seismic lines are the most pervasive linear disturbance associated with oil and gas development in the boreal forests of western North America. The width and orientation of seismic lines may influence microclimatic edge effects that could alter biotic responses, including tree recruitment. We examined light intensity, air temperature, relative humidity, and tree regeneration within seismic lines and adjacent forests to: (1) compare abiotic conditions between wide (6–8 m) and narrow (3–4 m) seismic lines; (2) quantify microclimatic edge effects of seismic lines of different widths and orientations; and (3) relate patterns in tree regeneration density to local patterns in the abiotic environment. We sampled interior forests and 24 seismic lines that were wide or narrow and orientated east-west or north-south in poor mesic ecosites of northeast Alberta, Canada. Microclimatic conditions in seismic line centres were generally intermediate between interior forest and well pads, with narrow seismic lines more similar to interior forest and wide seismic lines more similar to well pads. Light intensity on wide seismic line centres was at least 1.5 times higher than on narrow seismic line centres and up to 3.8 times higher than interior forest. Edge effects on light intensity extended up to 10 m into the forest adjacent to wide lines, but were restricted to the forest edge (at the interface) of narrow lines. Compared to interior forest, day temperature was up to 2.8 °C and 0.8 °C higher at edges of wide and narrow seismic lines, respectively. Relative humidity during the day was up to 7.3% and 3% lower at the edges of wide and narrow seismic lines, respectively, as compared to interior forest. At night, wide seismic line centres were up to 1.7 °C cooler and up to 8.2% more humid than narrow seismic line centres. Tree regeneration was highest where light intensity was highest (the centre of wide north-south seismic lines) and a 10-fold increase in light intensity resulted in 5.8 times more regenerating trees. This study reveals that seismic line width and orientation affect abiotic factors within the linear disturbance and up to 10 m into the adjacent forest. Edge effects on the microclimate of seismic lines were most pronounced in wider seismic lines and along north (south-facing) forest edges. These findings provide a better understanding of the abiotic factors influencing biotic responses to linear anthropogenic disturbances.

Seismic lines are linear forest clearings used for oil and gas exploration. The mechanical opening of forests for these narrow (3&ndash, 10 meter) lines is believed to simplify microtopographic complexity and depress local topographic elevation. In treed peatlands, simplified microtopography limits tree regeneration by removing favourable microsites (hummocks) for tree recruitment and increasing the occurrence of flooding that reduces survival of tree seedlings. Little, however, has been done to quantify the microtopography of seismic lines and specifically the degree of alteration. Here, we measured microtopography at 102 treed peatland sites in northeast Alberta, Canada using a high precision hydrostatic altimeter (ZIPLEVEL PRO-2000) that measured variation in local topography of seismic lines and adjacent paired undisturbed forests. Sites were separated into four peatland ecosite types and the presence or absence of recent (&lt, 22 years) wildfires. Paired t-tests were used to compare microtopographic complexity and depression depth of seismic lines compared with adjacent forests. Microtopographic complexity on seismic lines was simplified by 20% compared to adjacent stands with no significant change between recently burned and unburned sites, nor between ecosites. Not only were seismic lines simplified, but they were also depressed in elevation by an average of 8 cm compared to adjacent forests with some minor variation between ecosites observed, but again not with recent wildfires. Thus, simplification of microtopographic complexity and the creation of depressions can persist decades after initial disturbance with some differences between peatland ecosites, implying the need for ecosite-specific restoration of topographic complexity. The importance of microtopography for tree regeneration on seismic lines remains an important question for reforestation of these disturbances and thus long-term recovery of habitat for species dependent on undisturbed peatlands, including woodland caribou.

Seismic lines are narrow linear (~3&ndash, 8 m wide) forest clearings that are used for petroleum exploration in Alberta&rsquo, s boreal forest. Many seismic lines have experienced poor tree regeneration since initial disturbance, with most failures occurring in treed peatlands that are used by the threatened woodland caribou (Rangifer tarandus caribou). Extensive networks of seismic lines, which often reach densities of 40 km/km2, are thought to have contributed to declines in caribou. The reforestation of seismic lines is therefore a focus of conservation. Methods to reforest seismic lines are expensive (averaging $12,500 per km) with uncertainty of which seismic lines need which treatments, if any, resulting in inefficiencies in restoration actions. Here, we monitored the effectiveness of treatments on seismic lines as compared to untreated seismic lines and adjacent undisturbed reference stands for treed peatlands in northeast Alberta, Canada. Mechanical site preparation (mounding and ripping) increased tree density when compared to untreated lines, despite averaging 3.8-years since treatment (vs. 22 years since disturbance for untreated). Specifically, treated lines had, on average, 12,290 regenerating tree stems/ha, which is 1.6-times more than untreated lines (7680 stems/ha) and 1.5-times more than the adjacent undisturbed forest (8240 stems/ha). Using only mechanical site preparation, treated seismic lines consistently have more regenerating trees across all four ecosites, although the higher amounts of stems that were observed on treated poor fens are not significant when compared to untreated or adjacent undisturbed reference stands.

Actinorhizal plants form a symbiotic association with the nitrogen-fixing actinobacteria Frankia. These plants have important economic and ecological benefits including land reclamation, soil stabilization, and reforestation. Recently, many non-Frankia actinobacteria have been isolated from actinorhizal root nodules suggesting that they might contribute to nodulation. Two Nocardia strains, BMG51109 and BMG111209, were isolated from Casuarina glauca nodules, and they induced root nodule-like structures in original host plant promoting seedling growth. The formed root nodule-like structures lacked a nodular root at the apex, were not capable of reducing nitrogen and had their cortical cells occupied with rod-shaped Nocardiae cells. Both Nocardia strains induced root hair deformation on the host plant. BMG111209 strain induced the expression of the ProCgNin:Gus gene, a plant gene involved in the early steps of the infection process and nodulation development. Nocardia strain BMG51109 produced three types of auxins (Indole-3-acetic acid [IAA], Indole-3-Byturic Acid [IBA] and Phenyl Acetic Acid [PAA]), while Nocardia BMG111209 only produced IAA. Analysis of the Nocardia genomes identified several important predicted biosynthetic gene clusters for plant phytohormones, secondary metabolites, and novel natural products. Co-infection studies showed that Nocardia strain BMG51109 plays a role as a helper bacteria promoting an earlier onset of nodulation. This study raises many questions on the ecological significance and functionality of Nocardia bacteria in actinorhizal symbioses.

The unimpeded growth of urban population has unfortunately paved way to spreading multiple infectious diseases that greatly puts a population the risk of incurring an outbreak had the spread of disease not been managed well. Dengue is a major contagious disease that has been plaguing the world ever since, and epidemic outbreaks trying to be mitigated and minimized by researchers. One way to predict the pattern of the disease on a macro scale is to use mathematical models to understand the dynamics of the epidemics caused by the disease. This study uses the SIR, SEIR, and SIR with Vertical Transmission to model the spread of dengue in NCR, Philippines within the year 2010. Afterwards, each model was then used to simulate two disease control methods: Constant Vaccination Strategy (CVS) and Quarantine, which controls the infection and recovery rate parameters with SIR with linear parameters having the highest accuracy among all the models the R 2 value being 0.99683. The created models are accurate hence can be used to simulate dengue dynamics in NCR. CVS and Quarantine substantially decreased the peak of the epidemic for all models, confirming those methods as effective deterrents dengue incidence

There is limited information on how velvet leaf blueberry (Vaccinium myrtilloides Michx.) responds to fires and existing small forest gaps associated with narrow linear disturbances. We measured the effects of narrow forest linear gaps from seismic lines used for oil and gas exploration versus adjacent (control) forests across a fire severity (% tree mortality) gradient on the presence, abundance (cover), vigor (height), and berry production of Vaccinium myrtilloides in recently (five-year) burned jack pine (Pinus banksiana Lamb.) forests near Fort McMurray, Alberta. Presence was greatest in forests that experienced low to moderately-high fire severities with declines at high fire severity. Abundance did not differ among seismic lines or adjacent forest, nor did it differ along a fire severity gradient. In contrast, vigor and berry production were greater on seismic lines compared to adjacent forests with fire severity positively affecting berry production, but not plant vigor. After controlling for changes in plant cover and vigor, berry production still increased with fire severity and within seismic lines compared with adjacent forests. Our findings suggest that narrow gaps from linear disturbances and fire severity interact to affect the fecundity (berry production) and growth (height) of Vaccinium myrtilloides. This has important implications for assessing the ecological effects of fire on linear disturbances associated with energy exploration in the western boreal forest.

Fall events are common to elderly people due to their deteriorating muscle structures caused by old age. Their relatively weaker bodies make them prone to accidents such as falls even when performing daily tasks. These fall events may leave physical or psychological consequences among them. Commonly, these events are associated with one or more identifiable risk factors such as weakness, unsteady gait, confusion, environment, and certain medications. Previous researches have shown that these events can be prevented using fall detection mechanisms. In this study, we investigate whether the analysis of muscle fatigue degree may enhance the performance of existing fall detection systems that utilize both surface electromyography (SEMG) and accelerometer (ACC) sensors. SEMG and ACC signals were measured and recorded from 20 healthy study volunteers. A series of pre-defined activities that mimic fall events were performed by the study volunteers. These activities were conducted in a controlled environment. Acquired SEMG signals were pre-processed to eliminate unwanted signals and distortion. Discriminative features were then extracted from the clean signals, and these extracted features were combined with the accelerometer data for classification using an Artificial Neural Network (ANN) classifier. Results showed that the combination of SEMG and ACC data have relatively increased the accuracy of fall detection systems.

Worldwide, human respiratory syncytial virus (RSV) is the most common etiological agent for acute lower respiratory tract infections (ALRI). RSV-ALRI is the major cause of hospital admissions in young children, and it can cause in-hospital deaths in children younger than six months old. Therefore, RSV remains one of the pathogens deemed most important for the generation of a vaccine. On the other hand, the effectiveness of a vaccine depends on the development of immunological memory against the pathogenic agent of interest. This memory is achieved by long-lived memory T cells, based on the establishment of an effective immune response to viral infections when subsequent exposures to the pathogen take place. Memory T cells can be classified into three subsets according to their expression of lymphoid homing receptors: central memory cells (TCM), effector memory cells (TEM) and resident memory T cells (TRM). The latter subset consists of cells that are permanently found in non-lymphoid tissues and are capable of recognizing antigens and mounting an effective immune response at those sites. TRM cells activate both innate and adaptive immune responses, thus establishing a robust and rapid response characterized by the production of large amounts of effector molecules. TRM cells can also recognize antigenically unrelated pathogens and trigger an innate-like alarm with the recruitment of other immune cells. It is noteworthy that this rapid and effective immune response induced by TRM cells make these cells an interesting aim in the design of vaccination strategies in order to establish TRM cell populations to prevent respiratory infectious diseases. Here, we discuss the biogenesis of TRM cells, their contribution to the resolution of respiratory viral infections and the induction of TRM cells, which should be considered for the rational design of new vaccines against RSV.

Background Management of inflammatory bowel disease (IBD) patients requires a multidisciplinary approach. Among the working team, the role of IBD nurse is expected to be particularly relevant when managing patients receiving biological therapies. We performed a survey to assess the presence of IBD nurse in centers where patients were receiving biologics. Methods For this Italian nationwide survey a specific questionnaire was prepared. IBD nurse was defined as a nurse directly involved in all phases of biological therapy, from pre-therapy screening, administration and monitoring during therapy, to follow up performed by a dedicated helpline, completed a specific training on biological therapy therapy, and observed international guidelines. Results A total of 53 Italian IBD centers participated in the survey, and 91 valid questionnaires were collected. Overall, 34 (37.4%) nurses could be classified as IBD specialists. IBD nurses had a significantly higher educational level than other nurses, they were more frequently operating in Central or Southern than in Northern Italy, they were working in an Academic center rather than in a General hospital, and in IBD centers with >25 patients on biological therapy. On the contrary, mean age, gender distribution, years of nursing, and years working in the IBD unit did not significantly differ between IBD and other nurses. Conclusions Our nationwide survey showed that the presence of an IBD nurse is still lacking in the majority of Italian IBD centers where patients receive biological therapies, suggesting a prompt implementation. Keywords Inflammatory bowel disease, biological therapy, management, nursing Ann Gastroenterol 2016; 29 (4): 492-496

Pneumoccal infection of a total knee replacement is rare. We present a case of hematogeous pneumoccocal infection of a revision total knee arthroplasty as a complication of disseminated pneumoccocal sepsis. The patient was successfully treated with two stage reimplantation in addition to 8 weeks of intravenous moxifloxacin and penicillin, and remains infection free and functions well over 3 years postoperatively.

Flags snap in the breeze and smoke hangs menacingly above the ground. Men clash, yield, and die in a desperate battle on the crest of a hill. These images merge to form John Trumbull's painting, The Death of General Warren at the Battle of Bunker's Hill, 17 June 1775 (Figure 1). It is a dramatic image that appears frequently in print as illustration and cover art. Art historians comment positively on its technical merits, offering a variety of intriguing interpretations. These interpretations, though, frequently overlook the historical context of the original painting. Historical applications pair the painting with an appropriate historical text, but rarely take the opportunity to interpret the painting as a source in its own right. Historian Louis Masur makes this point when he criticizes the use of images in textbooks. Pictures, Masur argues, have become necessary but are not as a general rule presented in a way that asks or even allows for a complete reading of those same images. The loss is not merely in textbooks and other publications. It also occurs in the classroom, where pictures have become necessary backdrops for computer-supported lectures, and on Web site applications, where images dress but seldom add to the text.This essay argues for a more complete use of images outside and inside the classroom. In doing so, it applies techniques from two disciplines — history and art history — to offer a more complete reading of John Trumbull's The Death of General Warren at Bunker's Hill. This reading is presented from multiple perspectives, including the historical context in which the image was created, the artist's connection to the subject, and his interpretive and technical choices.

On April 20, 1778, Reverend Jacob Cushing, a Congregationalist minister from nearby Waltham, stepped onto the green at Lexington, Massachusetts, to deliver a sermon marking the third anniversary of the Battle of Lexington. As battles go, Lexington had actually been a minor skirmish. But its symbolic importance as the first military conflict of the American Revolution had grown over the prior three years. Accordingly, Cushing called on the public memory of the battle to praise the sacrifice of every soldier who had fallen in combat since that first fatal day. But Cushing, mindful of the sacrifice that still lay ahead, also used the intensity of the moment to exhort his audience for a renewed commitment to the cause. "To arms," he shouted midway through his sermon! "To action, and the battle of the warrior!" "The honour and glory of GOD," Cushing continued, "and the salvation of your country under GOD, call aloud upon all."1 Cushing was not innovating. By 1778, religious symbolism, nascent nationalism, and hope born out of sacrifice infused sermons, orations, editorials, and private correspondence. John Adams had touched on these same themes two years earlier in a report to his wife Abigail concerning ratification of the Declaration of Independence. "I am well aware of the Toil and Blood and Treasure, that it will cost Us to maintain this declaration, and support and defend these States," Adams wrote from Congress. "Yet, through all the Gloom ... I can see that the End is more than worth all the Means. And that

The role of phospholipids (PLs) in the signal transduction pathways that are activated by a mitogenic stimulus (foetal calf serum) in Trypanosoma cruzi epimastigotes (EPI) was investigated. Only phosphatidylinositol-bis-phosphate was significantly altered in this process. Other phosphoinositides, including major PLs such as phosphatidylcholine and phosphatidylethanolamine, were unaltered. Lysophosphatidic acid, reported to be the primary active substance in effects of serum in other systems, had no mitogenic activity when added to epimastigote cultures. Involvement of phosphoinositide-specific phospholipase C was established using the inhibitors ET-18-OCH3 and U73122, which prevented phosphatidylinositol-bis-phosphate hydrolysis; the latter compound decreased T. cruz proliferation. The intracellular signalling downstream to the phospholipase C was mediated by Ca2+/PL-dependent protein kinase and Ca2+/calmodulin-dependent protein kinase II, judging from the marked decrease in replication caused by the specific inhibitors staurosporine, derythro-sphingosine and KN-93. Previous reports have demonstrated a dual control of cell growth in EPI, whose proliferation is stimulated by the activation of a phospholipase C system and inhibited by activation of an adenylate cyclase system. Investigating this 'cross-talk' phenomenon, we observed that an increase in intracellular cAMP inhibited growth mediated by a cAMP-dependent protein kinase, but did not cause PL alterations, and also did not prevent the effect of serum on them.

Many physical processes have distributions of times between events that have non-normalizable, power law probability density functions ~PDF’s !. The moments of such distributions are not defined. We found that the PDF’s of the times between events of ventricular tachyarrhythmia ~rapid heart rate! and premature ventricular contractions have a power law form indicative of a non-normalizable distribution, and that the timing between these events cannot be meaningfully characterized by the mean frequency of such events. The Hurst analysis showed that there were self-similar correlations in the data. These results indicate that the physical processes that disrupt the normal rhythm of the heart produce a fractal pattern in the timing between these events. It also suggests that the mean and the variance of the frequency of these events may not be good measures to assess the status of patients with these arrhythmias and determine the effectiveness of therapeutic procedures. @S1063-651X~98!01209-4# PACS number~s!: 87.10.1e

Modern methods of encoding information into digital form include error check digits that are functions of the other information digits. When digital information is transmitted, the values of the error check digits can be computed from the information digits to determine whether the information has been received accurately. These error correcting codes make it possible to detect and correct common errors in transmission. The sequence of bases in DNA is also a digital code consisting of four symbols: A, C, G, and T. Does DNA also contain an error correcting code? Such a code would allow repair enzymes to protect the fidelity of nonreplicating DNA and increase the accuracy of replication. If a linear block error correcting code is present in DNA then some bases would be a linear function of the other bases in each set of bases. We developed an efficient procedure to determine whether such an error correcting code is present in the base sequence. We illustrate the use of this procedure by using it to analyze the lac operon and the gene for cytochrome c. These genes do not appear to contain such a simple error correcting code.

Three examples are given of how concepts from fractals and nonlinear dynamics have been used to analyze the voltages and currents recorded through ion channels in an attempt to determine the physical properties of ion channel proteins. (1) Early models had assumed that the switching of the ion channel protein from one conformational state to another can be represented by a Markov process that has no long-term correlations. However, one support for the existence of long-term correlations in channel function is that the currents recorded through individual ion channels have self-similar properties. These fractal properties can be characterized by a scaling function determined from the distribution of open and closed time intervals, which provides information on the distribution of activation energy barriers between the open and closed conformational substates of the ion channel protein and/or on how those energy barriers change in time. (2) Another support for such long-term correlations is that the whole-cell membrane voltage recorded across many channels at once may also have a fractal form. The Hurst rescaled range analysis of these fluctuations provides information on the type and degree of correlation in time of the functioning of ion channels. (3) The early models had also assumed that the switching from one state to another is an inherently random process driven by the energy from thermal fluctuations. More recently developed models have shown that deterministic dynamics may also produce the same distributions of open and closed times as those previously attributed to random events. This raises the possibility that the deterministic atomic and electrostatic forces play a role in switching the channel protein from one conformational shape to another. Debate exists about whether random, fractal, or deterministic models best represent the functioning of ion channels. However, fractal and deterministic dynamics provide a new approach to the study of ion channels that should be seriously considered by neuroscientists.

The voltage across the cell membrane of human T-lymphocyte cell lines was recorded by the whole cell patch clamp technique. We studied how this voltage fluctuated in time and found that these fluctuations have fractal characteristics. We used the Hurst rescaled range analysis and the power spectrum of the increments of the voltage (sampled at 0.01-sec intervals) to characterize the time correlations in these voltage fluctuations. Although there was great variability in the shape of these fluctuations from different cells, they all could be represented by the same fractal form. This form displayed two different regimes. At short lags, the Hurst exponent H = 0.76 +/- 0.05 (SD) and, at long lags, H = 0.26 +/- 0.04 (SD). This finding indicated that, over short time intervals, the correlations were persistent (H0.5), that is, increases in the membrane voltage were more likely to be followed by additional increases. However, over long time intervals, the correlations were antipersistent (H0.5), that is, increases in the membrane voltage were more likely to be followed by voltage decreases. Within each time regime, the increments in the fluctuations had characteristics that were consistent with those of fractional Gaussian noise (fGn), and the membrane voltage as a function of time had characteristics that were consistent with those of fractional Brownian motion (fBm).

After their axons have been severed, nerve cells can achieve functional recovery either by regrowth of the injured cells or by direct repair of the injured cell at the site of injury. Direct repair of a severed axon promises the advantages of preserving the viability and existing connections of the axon distal to the injury. We report here the first successful axon reconnection in the earthworm (Lumbricus terrestris) medial giant axon (MGA) in vitro system (1) by the application of well-focused 15 nsec, 5 to 50 muJ/pulse, 308 nm laser pulses. Axon reconnection is documented by light and electron microscopy, as well as by transfer of the iontophoretically injected fluorescent dye, Lucifer Yellow, across the reconnected MGA segments.

The frequency of Bromeliaceae and other plant breeding places where Aedes aegypti can be found is reported during two consecutive operational cycles (focal treatment) in the city of Rio de Janeiro. These cycles took place from November 12 2000 to March 9 2001 and from March 12 2001 to June 15 2001. This study concentrates on the epidemiological implications resulting from the growing use of these plants as decorative living objects.

Relata-se a freqüência de vegetais Bromeliaceae e de outros criadouros com plantas positivos para Aedes aegypti durante dois ciclos operacionais (tratamento focal) consecutivos no Município do Rio de Janeiro, RJ, cujos períodos foram de 12 de novembro de 2000 a 9 de março de 2001 e 12 de março de 2001 a 15 de junho de 2001. O trabalho destaca as implicações epidemiológicas oriundas da crescente utilização dessas plantas para fins decorativos. The frequency of Bromeliaceae and other plant breeding places where Aedes aegypti can be found is reported during two consecutive operational cycles (focal treatment) in the city of Rio de Janeiro. These cycles took place from November 12 2000 to March 9 2001 and from March 12 2001 to June 15 2001. This study concentrates on the epidemiological implications resulting from the growing use of these plants as decorative living objects.

Relata-se a freqüência de vegetais Bromeliaceae e de outros criadouros com plantas positivos para Aedes aegypti durante dois ciclos operacionais (tratamento focal) consecutivos no Município do Rio de Janeiro, RJ, cujos períodos foram de 12 de novembro de 2000 a 9 de março de 2001 e 12 de março de 2001 a 15 de junho de 2001. O trabalho destaca as implicações epidemiológicas oriundas da crescente utilização dessas plantas para fins decorativos.

Background . Thromboembolism after Fontan's operation is attributed to low flow states, stasis in venous pathways, right to left shunts, blind cul-de-sacs, prosthetic materials, atrial arrhythmias, and hypercoagulable states. We assessed the efficacy of a strategy to reduce thromboembolic events including aspirin anticoagulation. Methods . From January 1996 through December 2000, 72 patients underwent Fontan procedures. Management included (1) avoidance of direct caval cannulation and central venous lines, (2) inotropic support for 48 to 72 hours to optimize cardiac output, (3) aortopulmonary anastomosis or suture closure of patent pulmonary valves, and (4) administration of aspirin (81 mg per day) beginning on postoperative day one. No other anticoagulation strategies were used. Surveillance included intraoperative and postoperative transesophageal echo, transthoracic echo at discharge, at first reevaluation, and at 6 month intervals, and catheterization 1 year after surgery. Results . There were no early or late deaths. Follow-up was completed with 2,882 patient-months and a mean of 40 months. There were no documented thromboembolic events; however, all suspicious occurrences were investigated by echo and brain imaging. There were no hemorrhagic events or aspirin-related complications. Conclusions . Low dose aspirin can be used safely in young patients with Fontan connections. At intermediate follow-up, the strategies described appear effective in preventing thromboembolic complications. Routine use of more aggressive anticoagulation regimens seems unwarranted.