503 research outputs found
Control of Vulval Cell Division Number in the Nematode Oscheius/Dolichorhabditis sp. CEW1
Spatial patterning of vulval precursor cell fates is achieved through a different two-stage induction mechanism in the nematode Oscheius/Dolichorhabditis sp. CEW1 compared with Caenorhabditis elegans. We therefore performed a genetic screen for vulva mutants in Oscheius sp. CEW1. Most mutants display phenotypes unknown in C. elegans. Here we present the largest mutant category, which affects division number of the vulva precursors P(4-8).p without changing their fate. Among these mutations, some reduce the number of divisions of P4.p and P8.p specifically. Two mutants omit the second cell cycle of all vulval lineages. A large subset of mutants undergo additional rounds of vulval divisions. We also found precocious and retarded heterochronic mutants. Whereas the C. elegans vulval lineage mutants can be interpreted as overall (homeotic) changes in precursor cell fates with concomitant cell cycle changes, the mutants described in Oscheius sp. CEW1 do not affect overall precursor fate and thereby dissociate the genetic mechanisms controlling vulval cell cycle and fate. Laser ablation experiments in these mutants reveal that the two first vulval divisions in Oscheius sp. CEW1 appear to be redundantly controlled by a gonad-independent mechanism and by a gonadal signal that operates partially independently of vulval fate induction
Surveying activated sludge changes during acclimation with artificial wastewater
Many processes in the chemical and pharmaceutical industries generate wastewater containing organic
toxic compounds and other kinds of xenobiotics. Usually, biological treatments are used to degrade a
great quantity of these substances. However, most of the time, the microorganisms are not adapted and
the treatment can be blocked. Therefore, the first step to make a continuous reactor operative is the
acclimation, i.e., the adaptation of the microorganisms to a specific substrate. During this particular step
of the process there is a selection and a multiplication of specialized microorganisms and physiological
transformations can occur in their metabolic system. Furthermore, combining image processing
techniques have already been successfully used to elucidate the activated sludge morphological changes
for both aggregated and filamentous bacteria contents, during such processes.
The experimental set-up is composed of an aerated reactor and a clarifier. The sludge is recycled from the
clarifier by a peristaltic pump. The complete mixing inside the reactor is guaranteed by the diffusion of
air from its bottom. The reactor was inoculated with biomass collected from a wastewater treatment plant
and fed with an artificial wastewater based on meat extract. During acclimation, chemical parameters
were measured in the influent, reactor and effluent, in order to verify the stability of the process. To
complete the evaluation of the process, microscopy acquisition and image processing and analysis
techniques were performed for aggregates and filamentous bacteria characterization for bright field, Gram
and poly-ÎČ-hydroxybutyrate (PHB) staining images. The information extracted from those images
allowed for aggregates and filamentous bacteria contents inspection, identification of PHB storing
microorganisms and, gram-positive and gram-negative filamentous bacteria recognition. Figure 1 presents
activated sludge samples at the beginning and at the end of the acclimation phase. It was found in this
study that biomass changes during the acclimation phase could be effectively monitored, combining
image analysis information and chemical parameters
Gemcitabine and oxaliplatin (GEMOX) in gemcitabine refractory advanced pancreatic adenocarcinoma: a phase II study
Gemcitabine and oxaliplatin (GEMOX) are active as first-line therapy against advanced pancreatic cancer. This study aims to evaluate the activity and tolerability of this combination in patients refractory to standard gemcitabine (GEM). A total of 33 patients (median age of 57) were included with locally advanced and metastatic evaluable diseases, who had progressed during or following GEM therapy. The GEMOX regimen consisted of 1000âmgâmâ2 of GEM at a 100-min infusion on day 1, followed on day 2 by 100âmgâmâ2 of oxaliplatin at a 2-h infusion; a cycle that was given every 2 weeks. All patients received at least one cycle of GEMOX (median 5; range 1â29). Response by 31 evaluable patients was as follows: PR: 7/31(22.6%), s.d. â©Ÿ8 weeks: 11/31(35.5%), s.d. <8 weeks: 1/31(3.2%), PD: 12/31(38.7%). Median duration of response and TTP were 4.5 and 4.2 months, respectively. Median survival was 6 months (range 0.5â21). Clinical benefit response was observed in 17/31 patients (54.8%). Grade III/IV non-neurologic toxicities occurred in 12/33 patients (36.3%), and grade I, II, and III neuropathy in 17(51%), 3(9%), and 4(12%) patients, respectively. GEMOX is a well-tolerated, active regimen that may provide a benefit to patients with advanced pancreatic cancer after progression following standard gemcitabine treatment
Embryonic development of pleuropodia of the cicada, Magicicada cassini
In many insects the first abdominal segment possesses embryonic appendages called pleuropodia. Here we show the embryogenesis of pleuropodial cells of the periodical cicada, Magicicada cassini (Fisher 1851) (Insecta, Homoptera, Cicadidae). An antibody, anti-horseradish perioxidase (HRP), that is usually neuron-specific strongly marked the pleuropodial anlagen and revealed their ectodermal origin shortly after limb bud formation. Thereafter the cells sank into the epidermis and their apical parts enlarged. A globular part protruded from the body wall. Filamentous structures were marked at the stem region and into the apical dilation. In later embryonic stages the pleuropodia degenerated. Despite the binding of anti-HRP the cells had no morphological neuronal characters and cannot be regarded as neurons. The binding indicates that glycosylated cell surface molecules contribute to the adhesion between the presumably glandular pleuropodial cells. In comparison, anti-HRP does not mark the pleuropodia of Orthoptera
Cetuximab plus gemcitabine/oxaliplatin (GEMOXCET) in first-line metastatic pancreatic cancer: a multicentre phase II study
Targeting the epidermal growth factor receptor pathway in pancreatic cancer seems to be an attractive therapeutic approach. This study assessed the efficacy of cetuximab plus the combination of gemcitabine/oxaliplatin in metastatic pancreatic cancer. Eligible subjects had histological or cytological diagnosis of metastatic pancreatic adenocarcinoma. The primary end point was response according to RECIST. Patients received cetuximab 400âmgâmâ2 at first infusion followed by weekly 250âmgâmâ2 combined with gemcitabine 1000âmgâmâ2 as a 100âmin infusion on day 1 and oxaliplatin 100âmgâmâ2 as a 2-h infusion on day 2 every 2 weeks. Between January 2005 and August 2006, a total of 64 patients (22 women (34%), 42 men (66%); median age 64 years (range 31â78)) were enrolled at seven study centres. On October 2007, a total of 17 patients were alive. Sixty-two patients were evaluable for baseline and 61 for assessment of response to treatment in an intention-to-treat analysis. Six patients had an incomplete drug combination within the first cycle of the treatment plan (n=4 hypersensitivity reactions to the first cetuximab infusion, n=2 refused to continue therapy). Reported grade 3/4 toxicities (% of patients) were leukopaenia 15%, anaemia 8%, thrombocytopaenia 10%, diarrhoea 7%, nausea 18%, infection 18% and allergy 7%. Cetuximab-attributable skin reactions occurred as follows: grade 0: 20%, grade 1: 41%, grade 2: 30% and grade 3: 10%. The intention-to-treat analysis of 61 evaluable patients showed an overall response rate of 33%, including 1 (2%) complete and 19 (31%) partial remissions. There were 31% patients with stable and 36% with progressive disease or discontinuation of the therapy before re-staging. The presence of a grade 2 or higher skin rash was associated with a higher likelihood of achieving objective response. Median time to progression was 118 days, with a median overall survival of 213 days. A clinical benefit response was noted in 24 of the evaluable 61 patients (39%). The addition of cetuximab to the combination of gemcitabine and oxaliplatin is well tolerated but does not increase response or survival in patients with metastatic pancreatic cancer
ComPASS : a tool for distributed parallel finite volume discretizations on general unstructured polyhedral meshes
Characterizing Magnetic Field Morphologies in Three Serpens Protostellar Cores with ALMA
With the aim of characterizing the dynamical processes involved in the formation of young protostars, we present high-angular-resolution ALMA dust polarization observations of the Class 0 protostellar cores Serpens SMM1, Emb 8(N), and Emb 8. With spatial resolutions ranging from 150 to 40 au at 870 ÎŒm, we find unexpectedly high values of the polarization fraction along the outflow cavity walls in Serpens Emb 8(N). We use 3 mm and 1 mm molecular tracers to investigate outflow and dense-gas properties and their correlation with the polarization. These observations allow us to investigate the physical processes involved in the radiative alignment torques (RATs) acting on dust grains along the outflow cavity walls, which experience irradiation from accretion processes and outflow shocks. The inner core of SMM1-a presents a polarization pattern with a poloidal magnetic field at the bases of the two lobes of the bipolar outflow. To the south of SMM1-a we see two polarized filaments, one of which seems to trace the redshifted outflow cavity wall. The other may be an accretion streamer of material infalling onto the central protostar. We propose that the polarized emission we see at millimeter wavelengths along the irradiated cavity walls can be reconciled with the expectations of RAT theory if the aligned grains present at <500 au scales in Class 0 envelopes have grown larger than the 0.1 ÎŒm size of dust grains in the interstellar medium. Our observations allow us to constrain the magnetic field morphologies of star-forming sources within the central cores, along the outflow cavity walls, and in possible accretion streamers
A bayesian meta-analysis of multiple treatment comparisons of systemic regimens for advanced pancreatic cancer
© 2014 Chan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: For advanced pancreatic cancer, many regimens have been compared with gemcitabine (G) as the standard arm in randomized controlled trials. Few regimens have been directly compared with each other in randomized controlled trials and the relative efficacy and safety among them remains unclear
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