90 research outputs found
Biological activity of Bacillus spp. evaluated on eggs and larvae of red palm weevil Rhynchophorus ferrugineus
This study was conducted to characterize the Bacillus populations associated with dead Rhynchophorus ferrugineus, to develop a biological control for the red palm weevil. Dead adult beetles, collected throughout Sicily, were used for isolating internal and external spore forming bacteria (SFB) microbiota. The isolates, preliminarily allotted to the Bacillaceae family, were tested at 4 concentrations (103 to 106 CFU/mL) for their ability to inhibit hatching of eggs of R. ferrugineus and were used at 106 CFU/mL to monitor their insecticidal activity against 10 day-old larvae. Total amounts of SFB measured outside the skeleton and in the inners part of the beetles were 5.59-6.94 and 5.17-7.05 Log CFU/g, respectively. Hatching was inhibited markedly by 9 isolates, representing 9 distinct strains of 7 species (Bacillus amyloliquefaciens, Bacillus cereus, Bacillus licheniformis, Bacillus megaterium, Bacillus pumilus, Bacillus subtilis, and Lysinibacillus sphaericus), especially by the strains B. pumilus GC43 and GC51, which exhibited lethal concentrations 50 (LC50) values of 1.60 × 103 and 9.84 × 103 CFU/mL, respectively. Among all the strains tested, only B. licheniformis CG62 exhibited significant insecticidal activity against red palm weevil larvae. The Bacillus isolates characterized and tested in this study inhibited the hatching of red palm weevils in a contact-dependent manner. Thus, these isolates can be used as a preventive rather than as a curative treatment.
Keywords Bacillus, Rhynchophorus ferrugineus, hatching assays, larvae, Pal
Thermal energy storage in a confined aquifer: Experimental results
This is the published version. Copyright 1979 American Geophysical UnionTo aid in testing the idea of storing thermal energy in aquifers, an experiment was performed by Auburn University in which 54,784 m3 of water was pumped from a shallow supply aquifer, heated to an average temperature of 55°C, and injected into a deeper confined aquifer where the ambient temperature was 20°C. After a storage period of 51 days, 55,345 m3 of water were produced from the confined aquifer. Throughout the experiment, which lasted approximately 6 months, groundwater temperatures were recorded at six depths in each of 10 observation wells, and hydraulic heads were recorded in five observation wells. In order to prevent errors due to thermal convection, most of the observation wells recording temperature had to be backfilled with sand. During the 41-day production period, the temperature of the produced water varied from 55° to 33°C, and 65% of the injected thermal energy was recovered. At no time was an appreciable amount of free thermal convection observed in the storage formation. The dominant heat dissipation mechanisms appeared to be hydrodynamic thermal dispersion and possible mixing of cold and hot water induced by clogging and unclogging of the injection-production well. On the basis of laboratory and field studies, it was concluded that clogging of the injection well, which constituted the major technical problem during the experiment, was caused by the freshwater-sensitive nature of the storage aquifer. Due to the relatively low concentration of cations in the supply water, clay particles would swell, disperse, and migrate until they became trapped in the relatively small pores connecting the larger pores. Surging the pump and back washing the injection well would dislodge the clogging particles and temporarily improve the storage formation permeability. The phenomenon seems largely independent of temperature because it was reproduced in the laboratory with unheated water. It may, however, depend on pore velocity. Future research should be directed toward procedures for selecting storage aquifers that will have minimal susceptibility to clogging and other geochemical problems. Procedures for overcoming such difficulties are needed also because clogging and related phenomena will be more the rule than the exception. Designing an aquifer thermal storage system for maximum energy recovery would involve selecting an appropriate aquifer, analyzing the effects of hydrodynamic thermal dispersion and thermal convection if it is predicted to occur, anticipating geochemical problems, designing the optimum supply-injection-production well configuration and injecting a sufficiently large volume of heated water to realize economies of scale related to increasing volume-surface area ratio
Spinach, a cyclops, and the search for a cure for prostate cancer
Abstract only availableOther than skin cancer, prostate cancer is the most prevalent form of cancer in men. The likelihood of developing prostate cancer increases with age; so that nearly every male will die with some form of prostate cancer though most likely not from the cancer itself. Prostate cancer is regulated by endocrine and dietary factors, as well as genetic predisposition. In the male reproductive tract, Sonic Hedgehog (Shh) signaling is necessary for the development of the prostate. It has also been found to be extremely important in the growth of a number of tumor types including prostate cancer, basal cell carcinoma (skin cancer), medulloblastoma, glioma, sarcoma, tumors of the digestive tract, small cell lung cancer and pancreatic carcinoma. The Lubahn lab has been studying the roles of Estrogen Receptors and estrogenic compounds on prostate cancer, and has recently used a series of phytoestrogens, natural estrogens found in plants, to inhibit the hedgehog-signaling pathway. One natural product, cyclopamine, is able to inhibit the pathway and has been shown to inhibit prostate cancer cell growth both in vitro and in vivo xenograft models. Additionally, some flavanoid compounds in spinach have been found to have a similar chemical structure to several other phytoestrogens that have been shown to have preventative effects on prostate cancer. A competitive binding assay was performed using various doses of cyclopamine and an unpurified spinach extract to determine Kd for both compounds to ER alpha and ER beta. The compounds were also tested in the NIH-3T3 Shh Light II cells, which have a stably transfected Gli-Luciferase reporter, to see if they downregulated the hedgehog signaling pathway.Food for the 21st Century Undergraduate Research Program in Nutritional Science
An Expanded Multi-scale Monte Carlo Simulation Method for Personalized Radiobiological Effect Estimation in Radiotherapy: a feasibility study
A novel and versatile “bottom-up� approach is developed to estimate the radiobiological effect of clinic
radiotherapy. The model consists of multi-scale Monte Carlo simulations from organ to cell levels. At cellular level, accumulated damages are computed using a spectrum-based accumulation algorithm and predefined cellular damage database. The damage repair mechanism is modeled by an expanded reaction-rate two-lesion kinetic model, which were calibrated through replicating a radiobiological experiment. Multi-scale modeling is then performed on a lung cancer patient under conventional fractionated irradiation. The cell killing effects of two representative voxels (isocenter and peripheral voxel of the tumor) are computed and compared. At microscopic level, the nucleus dose and damage yields vary among all nucleuses within the voxels. Slightly larger percentage of cDSB yield is observed for the peripheral voxel (55.0%) compared to the isocenter one (52.5%). For isocenter voxel, survival fraction increase monotonically at reduced oxygen environment. Under an extreme anoxic condition (0.001%), survival fraction is calculated to be 80% and the hypoxia reduction factor reaches a maximum value of 2.24. In conclusion, with biological-related variations, the proposed multi-scale approach
is more versatile than the existing approaches for evaluating personalized radiobiological effects in
radiotherapy
Substrate Micropatterning as a New in Vitro Cell Culture System to Study Myelination
Artículo de publicación ISIMyelination is a highly regulated developmental
process whereby oligodendrocytes in the central nervous system
and Schwann cells in the peripheral nervous system ensheathe axons
with a multilayered concentric membrane. Axonal myelination
increases the velocity of nerve impulse propagation. In this work,
we present a novel in vitro system for coculturing primary dorsal root
ganglia neurons along with myelinating cells on a highly restrictive
and micropatterned substrate. In this new coculture system, neurons
survive for several weeks, extending long axons on defined Matrigel
tracks. On these axons, myelinating cells can achieve robust myelination, as demonstrated by the distribution of compact myelin
and nodal markers. Under these conditions, neurites and associated myelinating cells are easily accessible for studies on the
mechanisms of myelin formation and on the effects of axonal damage on the myelin sheath.Regenerative Medicine and Nanomedicine Initiative of the Canadian Institutes of Health Research (CIHR)
RMF-7028
FONDECYT
1080252
CIHR
Ministry of Industry of Canada
Rio Tinto Alcan
Molson Foundatio
Rapid and Long-Lasting Increase in Sites for Synapse Assembly during Late-Phase Potentiation in Rat Hippocampal Neurons
Long-term potentiation in hippocampal neurons has stages that correspond to the stages of learning and memory. Early-phase (10–30 min) potentiation is accompanied by rapid increases in clusters or puncta of presynaptic and postsynaptic proteins, which depend on actin polymerization but not on protein synthesis. We have now examined changes in pre- and postsynaptic puncta and structures during glutamate-induced late-phase (3 hr) potentiation in cultured hippocampal neurons. We find that (1) the potentiation is accompanied by long-lasting maintenance of the increases in puncta, which depends on protein synthesis, (2) most of the puncta and synaptic structures are very dynamic, continually assembling and disassembling at sites that are more stable than the puncta or structures themselves, (3) the increase in presynaptic puncta appears to be due to both rapid and more gradual increases in the number of sites where the puncta may form, and also to the stabilization of existing puncta, (4) under control conditions, puncta of postsynaptic proteins behave similarly to puncta of presynaptic proteins and share sites with them, and (5) the increase in presynaptic puncta is accompanied by a similar increase in presumably presynaptic structures, which may form at distinct as well as shared sites. The new sites could contribute to the transition between the early and late phase mechanisms of plasticity by serving as seeds for the formation and maintenance of new synapses, thus acting as local “tags” for protein synthesis-dependent synaptic growth during late-phase plasticity
Colpoisterectomia con colpocleisi per prolasso utero-vaginale completo nelle donne di età > 65 anni
Obiettivo: riportare l’outcome obiettivo e soggettivo a lungo termine dopo colpoisterectomia con colpocleisi nelle donne avanti negli anni. Materiali e metodo: abbiamo condotto uno studio retrospettivo su 32 pazienti di età > 65 anni. Le caratteristiche delle pazienti, i dati
dell’intervento e l’outcome obiettivo sono stati ottenuti dalla consultazione ambulatoriale delle cartelle cliniche delle pazienti. I dati soggettivi sono stati ottenuti mediante intervista telefonica standardizzata. Risultati: 32 pazienti di età compresa tra i 65 e gli 85 anni con
prolasso utero-vaginale di 3° grado, durante un tempo di 6 anni, sono state trattate con colpoisterectomia, colpocleisi, duplicatura sub-uretrale, accostamento alto degli elevatori, colporrafia anteriore e posteriore. La durata media dell’intervento è stata di 83 min. (range 55-130 min), il decremento medio dell’Hb è stato di 2,1 mg/dl (range 0,5-2,8 mg/dl) e la degenza media ospedaliera di 8,3 giorni (range 6-16 giorni). La recidiva del prolasso è stata osservata in 2 casi, i sintomi di incontinenza da sforzo persistono in 2 casi e si ripresentano in altri 2 casi. Non sono state osservate complicanze intraoperatorie, invece è stata osservata una complicanza postoperatoria (ematoma pelvico). Il follow-up va da un minimo di 6 mesi ad un massimo di 5 anni. All’intervista telefonica 18 pazienti si sono dichiarate molto soddisfatte, 10 soddisfatte e 4 insoddisfatte. Conclusioni: la colpoisterectomia con colpocleisi offre un trattamento efficace nel trattamento del prolasso utero-vaginale completo nelle donne avanti negli anni
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