415 research outputs found

    Communication-aware information gathering with dynamic information flow

    Full text link
    © The Author(s) 2014. We are interested in the problem of how to improve estimation in multi-robot information gathering systems by actively controlling the rate of communication between robots. Communication is essential in such systems for decentralized data fusion and decision-making, but wireless networks impose capacity constraints that are frequently overlooked. In order to make efficient use of available capacity, it is necessary to consider a fundamental trade-off between communication cost, computation cost and information value. We introduce a new problem, dynamic information flow, that formalizes this trade-off in terms of decentralized constrained optimization. We propose algorithms that dynamically adjust the data rate of each communication link to maximize an information gain metric subject to constraints on communication and computation resources. The metric is balanced against the communication resources required to transmit data and the computation cost of processing sensor data to form observations. The optimization process selectively routes raw sensor data or processed observation data to zero, one or many robots. Our algorithms therefore allow large systems with many different types of sensors and computational resources to maximize information gain performance while satisfying realistic communication constraints. We also present experimental results with multiple ground robots and multiple sensor types that demonstrate the benefit of dynamic information flow in comparison to simpler bandwidth-limiting methods

    Treatment of Slaughterhouse Waste Water Mixed with Serum from Lacteal Industry of Extremadura in Spain to Produce Clean Energy

    Get PDF
    The problem of slaughterhouse waste water can be resolved by mixing it with serum from lacteal industry to produce a biogas. The effect of serum addition on the anaerobic co-digestion of solid and liquid slaughterhouse waste has been studied. The experimental device consisted of a continuous digester by recirculation of biogas produced in the anaerobic digestion. The input effluent was a mixture of slaughterhouse waste from Badajoz city (Spain) and animal serum in a proportion of 20%. The anaerobic digestion was developed in a complete mixing continuous digester with a capacity of 6.2 L at 37 °C and a feed rate of 350 mL/day. From the results obtained for the co-digestion of the feeding effluent of the slaughterhouse waste, without and with serum added, in the same operating conditions, comparative data about the biological depuration and biogas production have been obtained. A 10 L biogas production was obtained with the slaughterhouse waste and 18 L with the slaughterhouse waste with serum added. In conclusion, the highest energetic yield (97.52% higher) was obtained in the second case, due to the positive action of catalytic enzymes present in the animal serum

    Computing Cutting Time in Turning Operation Based on AutoCAD Drawings.

    Get PDF
    In view of importance the cutting time, it is considered one of the most important factors in different machining processes where it affects production time, cycle time, and product cost consequently. This research aims to build up a system for computing cutting time in turning operations from AutoCAD drawings. The proposed system has been built using Visual Basic programming language and interfacing it with AutoCAD by Visual Basic for Application (VBA) Technique. The system is able to compute cutting time from the drawings according to the color of each solid entity; these colors were defined previously in the system. They are related to the type of turning operation (external, internal, and facing turning operations) as well as the rough and finish machining operations. The system was examined with two models, and it was accurate and efficient. It is possible consideration the proposed system step toward the integration between CAPP/CAM system

    Light-based devices for the treatment of facial erythema and telangiectasia

    Get PDF
    Facial erythema is one of the most common outpatient complaints in dermatology. There are various causes of facial erythema and several devices are available for its treatment. Pulsed dye laser (PDL) and intense pulsed light (IPL) are the two common light devices used for these conditions. In this review, we evaluated the literature to assess efficacy of IPL versus PDL in facial erythema and telangiectasia. We searched published articles including clinical trials or reviews articles, case series, and case reports. Electronic databases (MEDLINE and PubMed) were searched to retrieve the articles. Reference lists of selected articles were also considered for the review. Articles published in English language until June 2021 were considered for this review

    The first survey addressing patients with BMI over 50: a survey of 789 bariatric surgeons

    Get PDF
    Background: Bariatric surgery in patients with BMI over 50 kg/m2 is a challenging task. The aim of this study was to address main issues regarding perioperative management of these patients by using a worldwide survey. Methods: An online 48-item questionnaire-based survey on perioperative management of patients with a BMI superior to 50 kg/m2 was ideated by 15 bariatric surgeons from 9 different countries. The questionnaire was emailed to all members of the International Federation of Surgery for Obesity (IFSO). Responses were collected and analyzed by the authors. Results: 789 bariatric surgeons from 73 countries participated in the survey. Most surgeons (89.9%) believed that metabolic/bariatric surgery (MBS) on patients with BMI over 50 kg/m2 should only be performed by expert bariatric surgeons. Half of the participants (55.3%) believed that weight loss must be encouraged before surgery and 42.6% of surgeons recommended an excess weight loss of at least 10%. However, only 3.6% of surgeons recommended the insertion of an Intragastric Balloon as bridge therapy before surgery. Sleeve Gastrectomy (SG) was considered the best choice for patients younger than 18 or older than 65 years old. SG and One Anastomosis Gastric Bypass were the most common procedures for individuals between 18 and 65 years. Half of the surgeons believed that a 2-stage approach should be offered to patients with BMI > 50 kg/m2, with SG being the first step. Postoperative thromboprophylaxis was recommended for 2 and 4 weeks by 37.8% and 37.7% of participants, respectively. Conclusion: This survey demonstrated worldwide variations in bariatric surgery practice regarding patients with a BMI superior to 50 kg/m2. Careful analysis of these results is useful for identifying several areas for future research and consensus building

    A Switch from a Gradient to a Threshold Mode in the Regulation of a Transcriptional Cascade Promotes Robust Execution of Meiosis in Budding Yeast

    Get PDF
    Tight regulation of developmental pathways is of critical importance to all organisms, and is achieved by a transcriptional cascade ensuring the coordinated expression of sets of genes. We aimed to explore whether a strong signal is required to enter and complete a developmental pathway, by using meiosis in budding yeast as a model. We demonstrate that meiosis in budding yeast is insensitive to drastic changes in the levels of its consecutive positive regulators (Ime1, Ime2, and Ndt80). Entry into DNA replication is not correlated with the time of transcription of the early genes that regulate this event. Entry into nuclear division is directly regulated by the time of transcription of the middle genes, as premature transcription of their activator NDT80, leads to a premature entry into the first meiotic division, and loss of coordination between DNA replication and nuclear division. We demonstrate that Cdk1/Cln3 functions as a negative regulator of Ime2, and that ectopic expression of Cln3 delays entry into nuclear division as well as NDT80 transcription. Because Ime2 functions as a positive regulator for premeiotic DNA replication and NDT80 transcription, as well as a negative regulator of Cdk/Cln, we suggest that a double negative feedback loop between Ime2 and Cdk1/Cln3 promotes a bistable switch from the cell cycle to meiosis. Moreover, our results suggest a regulatory mode switch that ensures robust meiosis as the transcription of the early meiosis-specific genes responds in a graded mode to Ime1 levels, whereas that of the middle and late genes as well as initiation of DNA replication, are regulated in a threshold mode

    The Rho GDI Rdi1 regulates Rho GTPases by distinct mechanisms

    Get PDF
    © 2008 by The American Society for Cell Biology. Under the License and Publishing Agreement, authors grant to the general public, effective two months after publication of (i.e.,. the appearance of) the edited manuscript in an online issue of MBoC, the nonexclusive right to copy, distribute, or display the manuscript subject to the terms of the Creative Commons–Noncommercial–Share Alike 3.0 Unported license (http://creativecommons.org/licenses/by-nc-sa/3.0).The small guanosine triphosphate (GTP)-binding proteins of the Rho family are implicated in various cell functions, including establishment and maintenance of cell polarity. Activity of Rho guanosine triphosphatases (GTPases) is not only regulated by guanine nucleotide exchange factors and GTPase-activating proteins but also by guanine nucleotide dissociation inhibitors (GDIs). These proteins have the ability to extract Rho proteins from membranes and keep them in an inactive cytosolic complex. Here, we show that Rdi1, the sole Rho GDI of the yeast Saccharomyces cerevisiae, contributes to pseudohyphal growth and mitotic exit. Rdi1 interacts only with Cdc42, Rho1, and Rho4, and it regulates these Rho GTPases by distinct mechanisms. Binding between Rdi1 and Cdc42 as well as Rho1 is modulated by the Cdc42 effector and p21-activated kinase Cla4. After membrane extraction mediated by Rdi1, Rho4 is degraded by a novel mechanism, which includes the glycogen synthase kinase 3β homologue Ygk3, vacuolar proteases, and the proteasome. Together, these results indicate that Rdi1 uses distinct modes of regulation for different Rho GTPases.Deutsche Forschungsgemeinschaf

    The Politics of Pleasure: Promenading on the Corniche and Beachgoing

    Get PDF
    Can the pleasures of young Palestinian women from refugee camps in promenading on the Beirut seaside Corniche on a warm summer evening be political? Or days spent at women-only beaches? If so, how do we understand such pleasure as everyday practices, as a politics of the present moment, or conversely (or simultaneously) as mechanisms of being co-opted into a broader apparatus of consumerist ideology and capitalist complacency? Drawing on ethnographic research over 2 years I argue that these moments of pleasure are caesuras in the massive apparatus of power – welded from strands of work, neoliberal practice, nationalist certitudes and political exclusion – which binds these women. These acts of pleasure cannot easily be categorised as ‘resistance’ but I argue that they should not facilely be considered reinforcements of hegemonic control either. They are momentary and ephemeral recognitions of ordinary life lived in hard times, attempts at clawing back an instant of joy from the drudgery of the everyday, and a surrender to the enjoyment of conviviality in public and urban spaces. If they are at all political, they are so because such conviviality is ever harder to sustain in the calamity of hopelessness that characterises so much politics today

    The selective elimination of messenger RNA underlies the mitosis–meiosis switch in fission yeast

    Get PDF
    The cellular programs for meiosis and mitosis must be strictly distinguished but the mechanisms controlling the entry to meiosis remain largely elusive in higher organisms. In contrast, recent analyses in yeast have shed new light on the mechanisms underlying the mitosis–meiosis switch. In this review, the current understanding of these mechanisms in the fission yeast Schizosaccharomyces pombe is discussed. Meiosis-inducing signals in this microbe emanating from environmental conditions including the nutrient status converge on the activity of an RRM-type RNA-binding protein, Mei2. This protein plays pivotal roles in both the induction and progression of meiosis and has now been found to govern the meiotic program in a quite unexpected manner. Fission yeast contains an RNA degradation system that selectively eliminates meiosis-specific mRNAs during the mitotic cell cycle. Mmi1, a novel RNA-binding protein of the YTH-family, is essential for this process. Mei2 tethers Mmi1 and thereby stabilizes the transcripts necessary for the progression of meiosis

    Best practice approach for redo-surgeries after sleeve gastrectomy, an expert's modified Delphi consensus

    Get PDF
    Background: Sleeve gastrectomy (SG) is the most common metabolic and bariatric surgical (MBS) procedure worldwide. Despite the desired effect of SG on weight loss and remission of obesity-associated medical problems, there are some concerns regarding the need to do revisional/conversional surgeries after SG. This study aims to make an algorithmic clinical approach based on an expert-modified Delphi consensus regarding redo-surgeries after SG, to give bariatric and metabolic surgeons a guideline that might help for the best clinical decision. Methods: Forty-six recognized bariatric and metabolic surgeons from 25 different countries participated in this Delphi consensus study in two rounds to develop a consensus on redo-surgeries after SG. An agreement/disagreement ≥ 70.0% on statements was considered to indicate a consensus. Results: Consensus was reached for 62 of 72 statements and experts did not achieve consensus on 10 statements after two rounds of online voting. Most of the experts believed that multi-disciplinary team evaluation should be done in all redo-procedures after SG and there should be at least 12 months of medical and supportive management before performing redo-surgeries after SG for insufficient weight loss, weight regain, and gastroesophageal reflux disease (GERD). Also, experts agreed that in case of symptomatic GERD in the presence of adequate weight loss, medical treatment for at least 1 to 2 years is an acceptable option and agreed that Roux-en Y gastric bypass is an appropriate option in this situation. There was disagreement consensus on efficacy of omentopexy in rotation and efficacy of fundoplication in the presence of a dilated fundus and GERD. Conclusion: Redo-surgeries after SG is still an important issue among bariatric and metabolic surgeons. The proper time and procedure selection for redo-surgery need careful considerations. Although multi-disciplinary team evaluation plays a key role to evaluate best options in these situations, an algorithmic clinical approach based on the expert's consensus as a guideline can help for the best clinical decision-making.info:eu-repo/semantics/publishedVersio
    corecore