Parametric survival models for interval-censored data with time-dependent covariates

We present a parametric family of regression models for interval-censored event-time (survival) data that accomodates both fixed (e.g. baseline) and time-dependent covariates. The model employs a three-parameter family of survival distributions that includes the Weibull, negative binomial, and log-logistic distributions as special cases, and can be applied to data with left, right, interval, or non-censored event times. Standard methods, such as Newton-Raphson, can be employed to estimate the model and the resulting estimates have an asymptotically normal distribution about the true values with a covariance matrix that is consistently estimated by the information function. The deviance function is described to assess model fit and a robust sandwich estimate of the covariance may also be employed to provide asymptotically robust inferences when the model assumptions do not apply. Spline functions may also be employed to allow for non-linear covariates. The model is applied to data from a long-term study of type 1 diabetes to describe the effects of longitudinal measures of glycemia (HbA1c) over time (the time-dependent covariate) on the risk of progression of diabetic retinopathy (eye disease), an interval-censored event-time outcome.     

Recurrent laryngeal nerve activity exhibits a 5-HT-mediated long-term facilitation and enhanced response to hypoxia following acute intermittent hypoxia in rat

A progressive and sustained increase in inspiratory-related motor output ("long-term facilitation") and an augmented ventilatory response to hypoxia occur following acute intermittent hypoxia (AIH). To date, acute plasticity in respiratory motor outputs active in the postinspiratory and expiratory phases has not been studied. The recurrent laryngeal nerve (RLN) innervates laryngeal abductor muscles that widen the glottic aperture during inspiration. Other efferent fibers in the RLN innervate adductor muscles that partially narrow the glottic aperture during postinspiration. The aim of this study was to investigate whether or not AIH elicits a serotonin-mediated long-term facilitation of laryngeal abductor muscles, and if recruitment of adductor muscle activity occurs following AIH. Urethane anesthetized, paralyzed, unilaterally vagotomized, and artificially ventilated adult male Sprague-Dawley rats were subjected to 10 exposures of hypoxia (10% O(2) in N(2), 45 s, separated by 5 min, n = 7). At 60 min post-AIH, phrenic nerve activity and inspiratory RLN activity were elevated (39 ± 11 and 23 ± 6% above baseline, respectively). These responses were abolished by pretreatment with the serotonin-receptor antagonist, methysergide (n = 4). No increase occurred in time control animals (n = 7). Animals that did not exhibit postinspiratory RLN activity at baseline did not show recruitment of this activity post-AIH (n = 6). A repeat hypoxia 60 min after AIH produced a significantly greater peak response in both phrenic and RLN activity, accompanied by a prolonged recovery time that was also prevented by pretreatment with methysergide. We conclude that AIH induces neural plasticity in laryngeal motoneurons, via serotonin-mediated mechanisms similar to that observed in phrenic motoneurons: the so-called "Q-pathway". We also provide evidence that the augmented responsiveness to repeat hypoxia following AIH also involves a serotonergic mechanism.     

Evolutionary history of the genus Trisopterus

The group of small poor cods and pouts from the genus Trisopterus, belonging to the Gadidae family, comprises four described benthopelagic species that occur across the North-eastern Atlantic, from the Baltic Sea to the coast of Morocco, and the Mediterranean. Here, we combined molecular data from mitochondrial (cytochrome b) and nuclear (rhodopsin) genes to confirm the taxonomic status of the described species and to disentangle the evolutionary history of the genus. Our analyses supported the monophyly of the genus Trisopterus and confirmed the recently described species Trisopterus capelanus. A relaxed molecular clock analysis estimated an Oligocene origin for the group (∼30 million years ago; mya) indicating this genus as one of the most ancestral within the Gadidae family. The closure and re-opening of the Strait of Gibraltar after the Messinian Salinity Crisis (MSC) probably triggered the speciation process that resulted in the recently described T. capelanus.     

Extraction, purification and characterization of the plant-produced HPV16 subunit vaccine candidate E7 GGG

Several studies indicated that biopharmaceuticals based on the recombinant protein E7 of human papillomavirus (HPV) can serve as therapeutic vaccines preventing the development of cancer in women infected with high-risk types of HPV such as HPV16. Here, we report effective extraction and purification of a plant-produced E7GGG-lichenase fusion protein, an HPV16 subunit vaccine candidate, from Nicotiana benthamiana plants, to a high yield. The target contains the modified HPV16 E7 protein internally fused to the surface loop of a truncated, hexa-His- and KDEL-tagged variant of bacterial lichenase, and has been previously shown to possess anti-cancer activity in an animal model. We purified the protein using a combination of immobilized metal-ion affinity chromatography and gel filtration. The achieved purity of the final product was 99% as confirmed by Coomassie or SYPRO Ruby staining after sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by analytical size exclusion chromatography coupled with multi-angle laser light scattering. The overall yield was 50% corresponding to 0.1g of protein per 1 kg plant biomass. Only slight changes in these parameters were observed during the process scale-up from 50 g to 1 kg of processed leaf biomass.     

Removal of surfactant dodecylbenzenesulfonate by consecutive use of ozonation and biodegradation

Successful surfactant removal from wastewater is often limited by the high concentration of the surfactant. The use of advanced oxidation processes can be the key to aid biological treatment of water containing high amounts of surfactants. The present study analyzes the biodegradation of the anionic surfactant sodium dodecylbenzenesulfonate (SDBS) and the effects of its combination with ozonation. SDBS pre‐ozonation favors the metabolism by microorganisms. Experimental results indicate that the application of a concentration of up to 60 μM of ozone for 60 min, prior to contact with microorganisms, increases the percentage of SDBS removed by biodegradation alone. These results demonstrate that the removal of SDBS and of the total organic carbon is increased by the consecutive use of ozonation and biodegradation.     

Taste difference thresholds for monosodium glutamate and sodium chloride in pigtail macaques (Macaca nemestrina) and spider monkeys (Ateles geoffroyi)

The purpose of this study was to determine taste difference thresholds for monosodium glutamate (MSG) and sodium chloride (NaCl) in pigtail macaques (Macaca nemestrina) and spider monkeys (Ateles geoffroyi). Using a two-bottle preference test of brief duration, three animals of each species were presented with four different reference concentrations of 50, 100, 200, and 400 mM of a tastant and tested for their ability to discriminate these from lower concentrations of the same tastant. The just noticeable differences (JNDs), expressed as Weber ratios (DeltaI/I), were found to range from 0.1 to 0.5 for MSG and 0.2 to 0.45 for NaCl in the pigtail macaques, with a significant tendency for higher Weber ratios with higher reference concentrations. In the spider monkeys, JNDs ranged from 0.15 to 0.4 for MSG and 0.1 to 0.25 for NaCl, with Weber ratios staying fairly constant across the reference concentrations tested. Thus, the JNDs were found to be generally similar in both species and to be at least as low as those found in humans for MSG and NaCl, as well as those found in spider monkeys for sucrose. The results support the assumption that both pigtail macaques and spider monkeys may use differences in perceived intensity of MSG and NaCl as a criterion for food selection.     

Role of hepatic macrophages during the viral haemorrhagic fever induced by African Swine Fever Virus

To ascertain the role played by the various liver monocyte-macrophage populations in the course of a viral hemorrhagic fever, fifteen pigs were inoculated intramuscularly with the highly virulent isolate of African Swine Fever Virus (ASFV) Espa?a-70 and slaughtered at 1-7 days post-inoculation (dpi). Samples of liver were fixed in different solutions and routinely processed for morphological, immunohistochemical and ultrastructural studies. Viral antigen (vp73) was detected from 3 dpi onward, mainly in circulating monocytes of sinusoid and Kupffer's cells (KC), as well as in portal macrophages and hepatocytes from 5 dpi. Anti-SWC3 immunolabelled cells were increased from 1 dpi, peaking between 3 and 5 dpi, thereafter declining until the end of the experiment. The significant increase in the number of sinusoidal circulating monocytes and KC expressing IL-1alpha, TNFalpha and IL-6 from 1 dpi, confirmed the secretory activation of these cells. The results show that in the course of an ASFV-induced hemorrhagic syndrome, hepatic macrophage populations undergo major quantitative and biosynthetic changes prior to virus detection, suggesting the existence of a mechanism by which the virus concentrates infectable cells, which subsequently spread the virus around the body.     

Pines and oaks in the restoration of Mediterranean landscapes of Spain: New perspectives for an old practice — a review

Pines have been extensively used for land restoration in the Mediterranean basin and in other parts of the world, since the late 19^th century. The theoretical basis supporting pine utilisation was its stress-tolerant and pioneer features, and their attributed role of facilitating the development of late-successional hardwoods in the long-term. In the present work, the use of pines and hardwoods in forest restoration is discussed in the frame of the current disturbance regime and social demands for Mediterranean forests. Large pine plantations have recently disappeared because of their sensitivity to fire (e.g., Pinus nigra) or because of the short fire-intervals (e.g., Pinus halepensis). Combined pine and oak plantations are proposed for degraded land restoration on the basis of the complementary features of both groups of species. Seeding and containerised seedling plantation, soil amendments and plantation techniques to reduce transplant shock are evaluated for reforestation under water-stressing conditions, on the basis of several experiments performed in eastern Spain. Both P. halepensis and Quercus ilex are tested.