mode Ultrasim does not converge with BSIMBULK model By feedproxy.google.com Published On :: Tue, 05 May 2020 09:16:51 GMT Hello, I am using ultrasim Version 18.1.0.314.isr5 64bit 03/26/2019 06:33 (csvcm20c-2). When I run my netlist, ultrasim is blocked in the first DC stage and takes forever. Then it will fail or never progress. I am using a 22nm BSIMBULK model. I tried to tune different accuracy and convergence aids options but noting works. When I run the same netlist with spectre it works fine with no problem. Also, If I use another model (not BULKSIM), ultrasim will work and converge with no problem. My first feeling is that ultrasim has a problem with using BSIMBULK model. Could you please advice, Thank you, Kotb Full Article
mode Is there a simple way of converting a schematic to an s-parameter model? By feedproxy.google.com Published On :: Fri, 08 May 2020 20:06:07 GMT Before I ask this, I am aware that I can output an s-parameter file from an SP analysis. I'm wondering if there is a simple way of creating an s-parameter model of a component. As an example, if I have an S-parameter model that has 200 ports and 150 of those ports are to be connected to passive components and the remaining 50 ports are to be connected to active components, I can simplify the model by connecting the 150 passive components, running an SP analysis, and generating a 50 port S-parameter file. The problem is that this is cumbersome. You've got to wire up 50 PORT components and then after generating the s50p file, create a new cellview with an nport component and connect the 50 ports with 50 new pins. Wiring up all of those port components takes quite a lot of time to do, especially as the "choosing analyses" form adds arrays in reverse (e.g. if you click on an array of PORT components called X<0:2> it will add X<2>, X<1>, X<0> instead of in ascending order) so you have to add all of them to the analyses form manually. Is any way of taking a schematic and running some magic "generate S-Parameter cellview from schematic cellview" function that automates the whole process? Full Article
mode The Elephant in the Room: Mixed-Signal Models By feedproxy.google.com Published On :: Wed, 05 Nov 2014 11:45:00 GMT Key Findings: Nearly 100% of SoCs are mixed-signal to some extent. Every one of these could benefit from the use of a metrics-driven unified verification methodology for mixed-signal (MD-UVM-MS), but the modeling step is the biggest hurdle to overcome. Without the magical models, the process breaks down for lack of performance, or holes in the chip verification. In the last installment of The Low Road, we were at the mixed-signal verification party. While no one talked about it, we all saw it: The party was raging and everyone was having a great time, but they were all dancing around that big elephant right in the middle of the room. For mixed-signal verification, that elephant is named Modeling. To get to a fully verified SoC, the analog portions of the design have to run orders of magnitude faster than the speediest SPICE engine available. That means an abstraction of the behavior must be created. It puts a lot of people off when you tell them they have to do something extra to get done with something sooner. Guess what, it couldn’t be more true. If you want to keep dancing around like the elephant isn’t there, then enjoy your day. If you want to see about clearing the pachyderm from the dance floor, you’ll want to read on a little more…. Figure 1: The elephant in the room: who’s going to create the model? Whose job is it? Modeling analog/mixed-signal behavior for use in SoC verification seems like the ultimate hot potato. The analog team that creates the IP blocks says it doesn't have the expertise in digital verification to create a high-performance model. The digital designers say they don’t understand anything but ones and zeroes. The verification team, usually digitally-centric by background, are stuck in the middle (and have historically said “I just use the collateral from the design teams to do my job; I don’t create it”). If there is an SoC verification team, then ensuring that the entire chip is verified ultimately rests upon their shoulders, whether or not they get all of the models they need from the various design teams for the project. That means that if a chip does not work because of a modeling error, it ought to point back to the verification team. If not, is it just a “systemic error” not accounted for in the methodology? That seems like a bad answer. That all makes the most valuable guy in the room the engineer, whose knowledge spans the three worlds of analog, digital, and verification. There are a growing number of “mixed-signal verification engineers” found on SoC verification teams. Having a specialist appears to be the best approach to getting the job done, and done right. So, my vote is for the verification team to step up and incorporate the expertise required to do a complete job of SoC verification, analog included. (I know my popularity probably did not soar with the attendees of DVCON with that statement, but the job has to get done). It’s a game of trade-offs The difference in computations required for continuous time versus discrete time behavior is orders of magnitude (as seen in Figure 2 below). The essential detail versus runtime tradeoff is a key enabler of verification techniques like software-driven testbenches. Abstraction is a lossy process, so care must be taken to fully understand the loss and test those elements in the appropriate domain (continuous time, frequency, etc.). Figure 2: Modeling is required for performance AFE for instance The traditional separation of baseband and analog front-end (AFE) chips has shifted for the past several years. Advances in process technology, analog-to-digital converters, and the desire for cost reduction have driven both a re-architecting and re-partitioning of the long-standing baseband/AFE solution. By moving more digital processing to the AFE, lower cost architectures can be created, as well as reducing those 130 or so PCB traces between the chips. There is lots of good scholarly work from a few years back on this subject, such as Digital Compensation of Dynamic Acquisition Errors at the Front-End of ADCS and Digital Compensation for Analog Front-Ends: A New Approach to Wireless Transceiver Design. Figure 3: AFE evolution from first reference (Parastoo) The digital calibration and compensation can be achieved by the introduction of a programmable solution. This is in fact the most popular approach amongst the mobile crowd today. By using a microcontroller, the software algorithms become adaptable to process-related issues and modifications to protocol standards. However, for the SoC verification team, their job just got a whole lot harder. To determine if the interplay of the digital control and the analog function is working correctly, the software algorithms must be simulated on the combination of the two. That is, here is a classic case of inseparable mixed-signal verification. So, what needs to be in the model is the big question. And the answer is, a lot. For this example, the main sources of dynamic error at the front-end of ADCs are critical for the non-linear digital filtering that is highly frequency dependent. The correction scheme must be verified to show that the nonlinearities are cancelled across the entire bandwidth of the ADC. This all means lots of simulation. It means that the right level of detail must be retained to ensure the integrity of the verification process. This means that domain experience must be added to the list of expertise of that mixed-signal verification engineer. Back to the pachyderm There is a lot more to say on this subject, and lots will be said in future posts. The important starting point is the recognition that the potential flaw in the system needs to be examined. It needs to be examined by a specialist. Maybe a second opinion from the application domain is needed too. So, put that cute little elephant on your desk as a reminder that the beast can be tamed. Steve Carlson Related stories - It’s Late, But the Party is Just Getting Started Full Article metrics-driven methodology real number modeling uvm CPF RNM UPF mixed signal MDV verification
mode Take Advantage of Advancements in Real Number Modeling and Simulation By feedproxy.google.com Published On :: Mon, 26 Feb 2018 23:00:00 GMT Verification is the top challenge in mixed-signal design. Bringing analog and digital domains together into unified verification planning, simulating, and debugging is a challenging task for rapidly increasing size and complexity of mixed-signal designs. To more completely verify functionality and performance of a mixed-signal SoC and its AMS IP blocks used to build it, verification teams use simulations at transistor, analog behavioral and real-number model (RNM) and RTL levels, and combination of these. In recent years, RNM and simulation is being adopted for functional verification by many, due to advantages it offers including simpler modeling requirements and much faster simulation speed (compared to a traditional analog behavioral models like Verilog-A or VHDL-AMS). Verilog-AMS with its wreal continue to be popular choice. Standardization of real number extensions in SystemVerilog (SV) made SV-RNM an even more attractive choice for MS SoC verification. Verilog-AMS/wreal is scalar real type. SV-RNM offers a powerful ability to define complex data types, providing a user-defined structure (record) to describe the net value. In a typical design, most analog nodes can be modeled using a single value for passing a voltage (or current) from one module to another. The ability to pass multiple values over a net can be very powerful when, for example, the impedance load impact on an analog signal needs to be modeled. Here is an example of a user-defined net (UDN) structure that holds voltage, current, and resistance values: When there are multiple drives on a single net, the simulator will need a resolution function to determine the final net value. When the net is just defined as a single real value, common resolution functions such as min, max, average, and sum are built into the simulator. But definition of more complex structures for the net also requires the user to provide appropriate resolution functions for them. Here is an example of a net with three drivers modeled using the above defined structural elements (a voltage source with series resistance, a resistive load, and a current source): To properly solve for the resulting output voltage, the resolution function for this net needs to perform Norton conversion of the elements, sum their currents and conductances, and then calculate the resolved output voltage as the sum of currents divided by sum of conductances. With some basic understanding of circuit theory, engineers can use SV-RNM UDN capability to model electrical behavior of many different circuits. While it is primarily defined to describe source/load impedance interactions, its use can be extended to include systems including capacitors, switching circuits, RC interconnect, charge pumps, power regulators, and others. Although this approach extends the scope of functional verification, it is not a replacement for transistor-level simulation when accuracy, performance verification, or silicon correlation are required: It simply provides an efficient solution for discretely modeling small analog networks (one to several nodes). Mixed-signal simulation with an analog solver is still the best solution when large nonlinear networks must be evaluated. Cadence provides a tutorial on EEnet usage as well as the package (EEnet.pkg) with UDN definitions and resolution functions and modeling examples. To learn more, please login to your Cadence account to access the tutorial. Full Article real number modeling analog Mixed-Signal RNM mixed-signal verification
mode Amnesty Slams Facebook, Google Over Business Models By packetstormsecurity.com Published On :: Thu, 21 Nov 2019 15:02:04 GMT Full Article headline privacy data loss google spyware facebook social
mode Foreshadow And Intel SGX Software Attestation: The Whole Trust Model Collapses By packetstormsecurity.com Published On :: Wed, 15 Aug 2018 14:35:56 GMT Full Article headline flaw cryptography intel
mode Leaks Expose Peculiar Facebook Moderation Policy By packetstormsecurity.com Published On :: Mon, 22 May 2017 16:54:30 GMT Full Article headline privacy data loss facebook social censorship
mode Social Media Giants Warn Of AI Moderation Errors As Coronavirus Empties Offices By packetstormsecurity.com Published On :: Tue, 17 Mar 2020 13:06:52 GMT Full Article headline virus google facebook twitter
mode modern11.zip By packetstormsecurity.com Published On :: Mon, 26 Aug 2002 16:21:13 GMT Modernz #11. VMS / VAX Full Article
mode Louisiana’s military families to benefit from ground-source geothermal and modern energy-saving devices By feedproxy.google.com Published On :: 2019-07-29T15:21:36Z Last week, Corvias announced that it had entered the final phase of its geothermal installation and energy upgrades effort at the U.S. Army’s Fort Polk in West-Central Louisiana, a milestone that once complete will not only modernize the aging infrastructure but save the Army significant money and benefit military families. Full Article Energy Efficiency News Geothermal
mode A modern Cinderella story: California’s record on wholesale distributed generation leaves much room for improvement By feedproxy.google.com Published On :: 2019-08-07T09:23:06Z California, long a progressive leader on renewable energy and climate change mitigation, has neglected a key market segment for renewable energy: the “community-scale,” or “wholesale distributed generation” (DG), market. This market segment is defined as projects below 20 megawatts that connect to the distribution grid and export power to the grid for sale. Full Article DER Microgrids C&I Opinion & Commentary
mode August the ‘Cleanest Energy Month of the Year in Modern Times’ in UK By feedproxy.google.com Published On :: 2018-09-07T08:26:00Z Full Article Wind Power DER Energy Efficiency
mode 10 Options and 5 Case Studies Show How to Reform Utility Business Models By feedproxy.google.com Published On :: 2018-11-12T16:18:07Z Experts from Rocky Mountain Institute, the Advanced Energy Economy Institute and America’s Power Plan have released a new report that shows why new utility business models are key to the energy transition. Full Article Microgrids Microgrids News DER Energy Efficiency Utility Integration Infrastructure
mode Louisiana’s military families to benefit from ground-source geothermal and modern energy-saving devices By feedproxy.google.com Published On :: 2019-07-29T15:21:36Z Last week, Corvias announced that it had entered the final phase of its geothermal installation and energy upgrades effort at the U.S. Army’s Fort Polk in West-Central Louisiana, a milestone that once complete will not only modernize the aging infrastructure but save the Army significant money and benefit military families. Full Article Energy Efficiency News Geothermal
mode New York Seeks to Reform the Energy Vision: Shift from Monopoly Model to "Utility 2.0" By feedproxy.google.com Published On :: 2014-05-12T14:52:00Z New York State is pushing its utility industry to shift away from a century-old business model into a system that can accommodate more power from solar and wind. Full Article Microgrids Energy Efficiency Hydropower Baseload Storage Energy Efficiency Rooftop Bioenergy Policy Wind Power Solar
mode Engineering Possibilities Versus Practical Implementation: Utility Portfolios and Business Models By feedproxy.google.com Published On :: 2015-04-30T11:40:00Z Europe’s utilities are re-evaluating their business models due to the energy transition. Members of POWER-GEN Europe’s Advisory Board consider how a reliance on fossil fuels is no longer politically desirable, forcing utilities to transform their portfolios to adapt to radical change. Full Article Microgrids Energy Efficiency Hydropower Baseload Storage Energy Efficiency Bioenergy Wind Power Solar Project Development Geothermal
mode The Perfect Model of a Spirit-Empowered Life (Galatians 5:16–26) By feeds.gty.org Published On :: Sun, 15 Apr 2018 00:00:00 Check here each week to keep up with the latest from John MacArthur's pulpit at Grace Community Church. Full Article Galatians
mode FCA consultation paper on discretionary commission models and commission disclosure By www.eversheds.com Published On :: 2019-10-24 1. FCA Final Report on Motor Finance In March 2019, the FCA published its Final Report on motor finance. Our briefing note on the Final Report can be found Full Article
mode Konexo launches hourly resourcing model By www.eversheds.com Published On :: 2020-04-23 New Resourcing+ service gives clients ultimate flexibility with interim support Konexo, a division of Eversheds Sutherland, has launched Resourcing+ an evolution of its existing resourcing service to be rolled out across its global network. Full Article
mode New Technologies and New Modes of Production Disrupt China's Automotive Industry By feedproxy.google.com Published On :: Thu, 02 Apr 2020 20:25:21 +0000 By Boy Lüthje HONOLULU (6 April 2020)—The development of electric and self-driving vehicles is bringing on a massive restructuring of the global automotive industry. Emerging forms of new and shared mobility undermine the very model of private car ownership that has underpinned the automotive industry since the days of Henry Ford. This is a summary only. Click the title for the full article, or visit www.EastWestCenter.org/Research-Wire for more. Full Article
mode Un modelo para dar gracias By feeds.gracia.org Published On :: Tue, 26 Nov 2019 00:00:00 PST La enseñanza bíblica en profundidad de John MacArthur lleva la verdad transformadora de la Palabra de Dios a millones de personas cada día. Full Article
mode InMode Ltd. (INMD) CEO Moshe Mizrahy On Q1 2020 Results - Earnings Call Transcript By seekingalpha.com Published On :: Wed, 06 May 2020 16:20:52 -0400 Full Article INMD SA Transcripts
mode Hyundai Motor Set to Develop Pickup Truck Model Aiming at U.S. Market By english.hankyung.com Published On :: 2017-08-24 07:55 Hyundai Motor is currently in the works to develop a pickup truck model for the U.S. market. Michael O'Brien, vice president in charge of product planning for Hyundai Motor America, said on August 22 in a press conference, "The top management approved a project to develop a pickup truck model." Pickup trucks are highly popular in the United States. There is only one pickup truck model available in Korea, which is Ssangyong Motor's Korando Sports.Hyundai Motor unveiled a pickup truck concept mode... Full Article
mode Ghana’s Abedi, Nigeria’s Okocha and Liberia’s Weah picked as ultimate role models By article.wn.com Published On :: Sat, 09 May 2020 15:36 GMT The African football legends provided inspiration for many during their playing days ...... Full Article
mode Local Government Briefing Note 6 of 2013 - State Aid Modernisation: proposed amendments to the Enabling and the Procedural Regulations By www.eversheds.com Published On :: 2013-01-23 The European Commission (the "EC") presented two proposals on 5 December 2012, as part of its State Aid Modernisation initiative. The proposals will include amendments to two key State aid instruments, the Enabling Regulation and... Full Article
mode French Competition Authority puts model agencies price-fixing practices in the spotlight By www.eversheds.com Published On :: 2016-12-07 On 29 September 2016, the French Competition Authority (l’Autorité de la concurrence - the “Autorité”) imposed a fine of EUR 2.4 million on 37 model agencies and their main trade association, the SYNAM, in relation to... Full Article
mode German data protection authorities agree on calculation model for GDPR fines By www.eversheds.com Published On :: 2019-10-14 While fines recently imposed by the French and UK data protection supervisory authorities have been high, the supervisory authorities in Germany have so far imposed rather moderate penalties. This could now be changed by a new model for calculating ... Full Article
mode Tyra Banks Admits Some America’s Next Top Model Moments Were Over the Line By article.wn.com Published On :: Sat, 09 May 2020 06:12 GMT Earlier this week, the Internet revisited clips of America’s Next Top Model, which premiered in 2003 on UPN and has aged pretty badly ever since, in which host ... More » ...... Full Article
mode Kerala Covid-19 Response Model for Emulation By www.ipsnews.net Published On :: Thu, 09 Apr 2020 11:30:24 +0000 Within weeks, the Covid-19 epidemic was classified by the World Health Organization (WHO) as an epidemic of international significance, triggering a pre-agreed WHO response. By the end of the first week of April, more than 1.3 million people had been confirmed as infected, with over 65,000 deaths across the world. Many governments of developing, especially […] The post Kerala Covid-19 Response Model for Emulation appeared first on Inter Press Service. Full Article Asia-Pacific Civil Society Development & Aid Economy & Trade Featured Global Headlines Health Humanitarian Emergencies TerraViva United Nations Jomo Kwame Sundaram & Anis Chowdhury
mode No, Sweden isn’t a miracle coronavirus model By www.japantimes.co.jp Published On :: Wed, 06 May 2020 04:18:18 +0900 The country's lockdown model is being lauded by the WHO, but it's a unique case whose death rate is much worse than its neighbors. Full Article Opinion lockdowns covid-19 Sweden model
mode ‘The Dutch East India Company in Early Modern Japan’: Water buffaloes, cassowaries and Arabian horses By www.japantimes.co.jp Published On :: Sun, 26 Apr 2020 06:20:01 +0900 From exotic animals to spectacles and chandeliers, Michael Laver’s “The Dutch East India Company in Early Modern Japan” shows how well-placed gifts were essential in ... Full Article Culture Nagasaki Dejima Dutch East India Company
mode Is Scripture Sufficient to Meet Modern Cultural Challenges? By feeds.gty.org Published On :: Wed, 09 Oct 2019 00:00:00 PST Twenty-first century evangelists and missionaries are confronted with a vastly different world to that of the early church. In the realms of communication and technology, the changes are immense. And in the eyes of many church growth proponents, a lot of modern advancements have left the Bible looking older than ever.READ MORE Full Article
mode Coronavirus spares China’s armed forces but disrupts PLA modernisation plans By www.scmp.com Published On :: Sat, 09 May 2020 12:00:11 +0800 China’s military may have been spared any coronavirus infections, but the global health crisis has slowed the progress of Chinese President Xi Jinping’s plan to transform the People’s Liberation Army into a modern fighting force capable of long-range power-projecting operations, experts say.According to China’s defence ministry, the world’s largest armed force – with about 2.3 million personnel – has had zero confirmed cases of Covid-19. In contrast, the US and Russian militaries, ranked second… Full Article
mode Rethinking Kenya’s industrial model post-Covid-19 crisis By www.nation.co.ke Published On :: 2020-05-08T19:54:00Z The government needs to encourage innovative technology that resonates with our requirements. Full Article
mode The revival mode By www.indianrealtynews.com Published On :: Wed, 12 Feb 2014 16:58:11 +0000 TNS Property market in the tricity and its periphery is coming back to life with fresh transactions and possessions being handed over in the existing projects Though the chill in the air has shown no signs of slackening so far in 2014, there are signs of a thaw in the realty scene in the tricity and its periphery areas in the new year. While 2013 had been tagged as one of the most dismal years for the property market in the Chandigarh, Panchkula and Mohali area by market watchers, no miracles were foreseen for 2014 in view of the soaring inflation figures, low GDP growth and impending general elections. But […] Full Article Chandigarh Other City
mode ADB, Mongolia Sign Loans to Modernize Vegetable Production, Irrigation By feedproxy.google.com Published On :: 2020-05-05 00:00:00 ADB and the Government of Mongolia today signed $40 million in loans and a $2 million Japan Fund for Poverty Reduction grant to support the modernization of government-owned irrigation networks and vegetable production in Mongolia. Full Article
mode Two Decade Partnership Helping Bring Kolkata’s Urban Services into Modern Age By www.adb.org Published On :: 2019-08-30 00:00:00 Kolkata and ADB are working systematically to update the city’s ancient urban systems after years of piecemeal approaches Full Article
mode SEZs: In standstill mode By www.indianrealtynews.com Published On :: Thu, 05 Sep 2013 13:04:34 +0000 On Monday, the government rolled out the promised “package of reforms” to boost the country’s exports. The commerce ministry notified the Amended Rules, 2013, for special economic zones (SEZs) launched with much fanfare over seven years ago. However, real estate developers are not very enthused by the amended policy. The reason, they say, is not just policy, but several other factors that have stifled the growth of a sector, which posted growth of over 121 per cent in exports in 2009-10. As per the amended policy, the minimum land requirement norms have been eased, graded scale for minimum land criteria has been introduced, an exit policy for SEZ units has […] Full Article Sez India Sezs India
mode AKG Lyra Ultra-HD, Multimode USB Microphone Make 2020 NAMM and CES Show Debut By news.harman.com Published On :: Tue, 07 Jan 2020 13:00:00 GMT NORTHRIDGE, Calif.—HARMAN Professional Solutions, the global leader in audio, video, lighting and control systems, today announced the AKG Lyra ultra-HD, multi-mode USB microphone will be making its 2020 tradeshow season debut at the 2020 NAMM show in... Full Article
mode London's Tate Modern to open new wing By feeds.reuters.com Published On :: Tue, 14 Jun 2016 17:09:00 -0400 Britain's Tate Modern gallery in London reveals additional building called the 'Switch House' which will open to the public on June 17. Full Article
mode Even Moderate Drinking Puts Many Older Adults at Risk By www.medicinenet.com Published On :: Sat, 9 May 2020 00:00:00 PDT Title: Even Moderate Drinking Puts Many Older Adults at RiskCategory: Health NewsCreated: 4/28/2010 6:10:00 PMLast Editorial Review: 4/29/2010 12:00:00 AM Full Article
mode Eating Fish in Moderation During Pregnancy Benefits Fetus: Study By www.medicinenet.com Published On :: Mon, 23 Mar 2020 00:00:00 PDT Title: Eating Fish in Moderation During Pregnancy Benefits Fetus: StudyCategory: Health NewsCreated: 3/20/2020 12:00:00 AMLast Editorial Review: 3/23/2020 12:00:00 AM Full Article
mode Modern Livestock Farming Can Pose Public Health Risk By www.medicinenet.com Published On :: Fri, 8 May 2020 00:00:00 PDT Title: Modern Livestock Farming Can Pose Public Health RiskCategory: Health NewsCreated: 5/7/2020 12:00:00 AMLast Editorial Review: 5/8/2020 12:00:00 AM Full Article
mode Pharmacologic Inhibitor of DNA-PK, M3814, Potentiates Radiotherapy and Regresses Human Tumors in Mouse Models By mct.aacrjournals.org Published On :: 2020-05-04T05:39:42-07:00 Physical and chemical DNA-damaging agents are used widely in the treatment of cancer. Double-strand break (DSB) lesions in DNA are the most deleterious form of damage and, if left unrepaired, can effectively kill cancer cells. DNA-dependent protein kinase (DNA-PK) is a critical component of nonhomologous end joining (NHEJ), one of the two major pathways for DSB repair. Although DNA-PK has been considered an attractive target for cancer therapy, the development of pharmacologic DNA-PK inhibitors for clinical use has been lagging. Here, we report the discovery and characterization of a potent, selective, and orally bioavailable DNA-PK inhibitor, M3814 (peposertib), and provide in vivo proof of principle for DNA-PK inhibition as a novel approach to combination radiotherapy. M3814 potently inhibits DNA-PK catalytic activity and sensitizes multiple cancer cell lines to ionizing radiation (IR) and DSB-inducing agents. Inhibition of DNA-PK autophosphorylation in cancer cells or xenograft tumors led to an increased number of persistent DSBs. Oral administration of M3814 to two xenograft models of human cancer, using a clinically established 6-week fractionated radiation schedule, strongly potentiated the antitumor activity of IR and led to complete tumor regression at nontoxic doses. Our results strongly support DNA-PK inhibition as a novel approach for the combination radiotherapy of cancer. M3814 is currently under investigation in combination with radiotherapy in clinical trials. Full Article
mode Modeling of the Coral Microbiome: the Influence of Temperature and Microbial Network By mbio.asm.org Published On :: 2020-03-03T01:30:27-08:00 ABSTRACT Host-associated microbial communities are shaped by extrinsic and intrinsic factors to the holobiont organism. Environmental factors and microbe-microbe interactions act simultaneously on the microbial community structure, making the microbiome dynamics challenging to predict. The coral microbiome is essential to the health of coral reefs and sensitive to environmental changes. Here, we develop a dynamic model to determine the microbial community structure associated with the surface mucus layer (SML) of corals using temperature as an extrinsic factor and microbial network as an intrinsic factor. The model was validated by comparing the predicted relative abundances of microbial taxa to the relative abundances of microbial taxa from the sample data. The SML microbiome from Pseudodiploria strigosa was collected across reef zones in Bermuda, where inner and outer reefs are exposed to distinct thermal profiles. A shotgun metagenomics approach was used to describe the taxonomic composition and the microbial network of the coral SML microbiome. By simulating the annual temperature fluctuations at each reef zone, the model output is statistically identical to the observed data. The model was further applied to six scenarios that combined different profiles of temperature and microbial network to investigate the influence of each of these two factors on the model accuracy. The SML microbiome was best predicted by model scenarios with the temperature profile that was closest to the local thermal environment, regardless of the microbial network profile. Our model shows that the SML microbiome of P. strigosa in Bermuda is primarily structured by seasonal fluctuations in temperature at a reef scale, while the microbial network is a secondary driver. IMPORTANCE Coral microbiome dysbiosis (i.e., shifts in the microbial community structure or complete loss of microbial symbionts) caused by environmental changes is a key player in the decline of coral health worldwide. Multiple factors in the water column and the surrounding biological community influence the dynamics of the coral microbiome. However, by including only temperature as an external factor, our model proved to be successful in describing the microbial community associated with the surface mucus layer (SML) of the coral P. strigosa. The dynamic model developed and validated in this study is a potential tool to predict the coral microbiome under different temperature conditions. Full Article
mode Host and Symbiont Cell Cycle Coordination Is Mediated by Symbiotic State, Nutrition, and Partner Identity in a Model Cnidarian-Dinoflagellate Symbiosis By mbio.asm.org Published On :: 2020-03-10T01:30:41-07:00 ABSTRACT The cell cycle is a critical component of cellular proliferation, differentiation, and response to stress, yet its role in the regulation of intracellular symbioses is not well understood. To explore host-symbiont cell cycle coordination in a marine symbiosis, we employed a model for coral-dinoflagellate associations: the tropical sea anemone Aiptasia (Exaiptasia pallida) and its native microalgal photosymbionts (Breviolum minutum and Breviolum psygmophilum). Using fluorescent labeling and spatial point-pattern image analyses to characterize cell population distributions in both partners, we developed protocols that are tailored to the three-dimensional cellular landscape of a symbiotic sea anemone tentacle. Introducing cultured symbiont cells to symbiont-free adult hosts increased overall host cell proliferation rates. The acceleration occurred predominantly in the symbiont-containing gastrodermis near clusters of symbionts but was also observed in symbiont-free epidermal tissue layers, indicating that the presence of symbionts contributes to elevated proliferation rates in the entire host during colonization. Symbiont cell cycle progression differed between cultured algae and those residing within hosts; the endosymbiotic state resulted in increased S-phase but decreased G2/M-phase symbiont populations. These phenotypes and the deceleration of cell cycle progression varied with symbiont identity and host nutritional status. These results demonstrate that host and symbiont cells have substantial and species-specific effects on the proliferation rates of their mutualistic partners. This is the first empirical evidence to support species-specific regulation of the symbiont cell cycle within a single cnidarian-dinoflagellate association; similar regulatory mechanisms likely govern interpartner coordination in other coral-algal symbioses and shape their ecophysiological responses to a changing climate. IMPORTANCE Biomass regulation is critical to the overall health of cnidarian-dinoflagellate symbioses. Despite the central role of the cell cycle in the growth and proliferation of cnidarian host cells and dinoflagellate symbionts, there are few studies that have examined the potential for host-symbiont coregulation. This study provides evidence for the acceleration of host cell proliferation when in local proximity to clusters of symbionts within cnidarian tentacles. The findings suggest that symbionts augment the cell cycle of not only their enveloping host cells but also neighboring cells in the epidermis and gastrodermis. This provides a possible mechanism for rapid colonization of cnidarian tissues. In addition, the cell cycles of symbionts differed depending on nutritional regime, symbiotic state, and species identity. The responses of cell cycle profiles to these different factors implicate a role for species-specific regulation of symbiont cell cycles within host cnidarian tissues. Full Article
mode Pyocin S5 Import into Pseudomonas aeruginosa Reveals a Generic Mode of Bacteriocin Transport By mbio.asm.org Published On :: 2020-03-10T01:30:42-07:00 ABSTRACT Pyocin S5 (PyoS5) is a potent protein bacteriocin that eradicates the human pathogen Pseudomonas aeruginosa in animal infection models, but its import mechanism is poorly understood. Here, using crystallography, biophysical and biochemical analyses, and live-cell imaging, we define the entry process of PyoS5 and reveal links to the transport mechanisms of other bacteriocins. In addition to its C-terminal pore-forming domain, elongated PyoS5 comprises two novel tandemly repeated kinked 3-helix bundle domains that structure-based alignments identify as key import domains in other pyocins. The central domain binds the lipid-bound common polysaccharide antigen, allowing the pyocin to accumulate on the cell surface. The N-terminal domain binds the ferric pyochelin transporter FptA while its associated disordered region binds the inner membrane protein TonB1, which together drive import of the bacteriocin across the outer membrane. Finally, we identify the minimal requirements for sensitizing Escherichia coli toward PyoS5, as well as other pyocins, and suggest that a generic pathway likely underpins the import of all TonB-dependent bacteriocins across the outer membrane of Gram-negative bacteria. IMPORTANCE Bacteriocins are toxic polypeptides made by bacteria to kill their competitors, making them interesting as potential antibiotics. Here, we reveal unsuspected commonalities in bacteriocin uptake pathways, through molecular and cellular dissection of the import pathway for the pore-forming bacteriocin pyocin S5 (PyoS5), which targets Pseudomonas aeruginosa. In addition to its C-terminal pore-forming domain, PyoS5 is composed of two tandemly repeated helical domains that we also identify in other pyocins. Functional analyses demonstrate that they have distinct roles in the import process. One recognizes conserved sugars projected from the surface, while the other recognizes a specific outer membrane siderophore transporter, FptA, in the case of PyoS5. Through engineering of Escherichia coli cells, we show that pyocins can be readily repurposed to kill other species. This suggests basic ground rules for the outer membrane translocation step that likely apply to many bacteriocins targeting Gram-negative bacteria. Full Article
mode The Min System Disassembles FtsZ Foci and Inhibits Polar Peptidoglycan Remodeling in Bacillus subtilis By mbio.asm.org Published On :: 2020-03-17T01:30:15-07:00 ABSTRACT A microfluidic system coupled with fluorescence microscopy is a powerful approach for quantitative analysis of bacterial growth. Here, we measure parameters of growth and dynamic localization of the cell division initiation protein FtsZ in Bacillus subtilis. Consistent with previous reports, we found that after division, FtsZ rings remain at the cell poles, and polar FtsZ ring disassembly coincides with rapid Z-ring accumulation at the midcell. In cells mutated for minD, however, the polar FtsZ rings persist indefinitely, suggesting that the primary function of the Min system is in Z-ring disassembly. The inability to recycle FtsZ monomers in the minD mutant results in the simultaneous maintenance of multiple Z-rings that are restricted by competition for newly synthesized FtsZ. Although the parameters of FtsZ dynamics change in the minD mutant, the overall cell division time remains the same, albeit with elongated cells necessary to accumulate a critical threshold amount of FtsZ for promoting medial division. Finally, the minD mutant characteristically produces minicells composed of polar peptidoglycan shown to be inert for remodeling in the wild type. Polar peptidoglycan, however, loses its inert character in the minD mutant, suggesting that the Min system not only is important for recycling FtsZ but also may have a secondary role in the spatiotemporal regulation of peptidoglycan remodeling. IMPORTANCE Many bacteria grow and divide by binary fission in which a mother cell divides into two identical daughter cells. To produce two equally sized daughters, the division machinery, guided by FtsZ, must dynamically localize to the midcell each cell cycle. Here, we quantitatively analyzed FtsZ dynamics during growth and found that the Min system of Bacillus subtilis is essential to disassemble FtsZ rings after division. Moreover, a failure to efficiently recycle FtsZ results in an increase in cell size. Finally, we show that the Min system has an additional role in inhibiting cell wall turnover and contributes to the "inert" property of cell walls at the poles. Full Article
mode Neutralizing Monoclonal Antibodies against the Gn and the Gc of the Andes Virus Glycoprotein Spike Complex Protect from Virus Challenge in a Preclinical Hamster Model By mbio.asm.org Published On :: 2020-03-24T01:31:00-07:00 ABSTRACT Hantaviruses are the etiological agent of hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (HCPS). The latter is associated with case fatality rates ranging from 30% to 50%. HCPS cases are rare, with approximately 300 recorded annually in the Americas. Recently, an HCPS outbreak of unprecedented size has been occurring in and around Epuyén, in the southwestern Argentinian state of Chubut. Since November of 2018, at least 29 cases have been laboratory confirmed, and human-to-human transmission is suspected. Despite posing a significant threat to public health, no treatment or vaccine is available for hantaviral disease. Here, we describe an effort to identify, characterize, and develop neutralizing and protective antibodies against the glycoprotein complex (Gn and Gc) of Andes virus (ANDV), the causative agent of the Epuyén outbreak. Using murine hybridoma technology, we generated 19 distinct monoclonal antibodies (MAbs) against ANDV GnGc. When tested for neutralization against a recombinant vesicular stomatitis virus expressing the Andes glycoprotein (GP) (VSV-ANDV), 12 MAbs showed potent neutralization and 8 showed activity in an antibody-dependent cellular cytotoxicity reporter assay. Escape mutant analysis revealed that neutralizing MAbs targeted both the Gn and the Gc. Four MAbs that bound different epitopes were selected for preclinical studies and were found to be 100% protective against lethality in a Syrian hamster model of ANDV infection. These data suggest the existence of a wide array of neutralizing antibody epitopes on hantavirus GnGc with unique properties and mechanisms of action. IMPORTANCE Infections with New World hantaviruses are associated with high case fatality rates, and no specific vaccine or treatment options exist. Furthermore, the biology of the hantaviral GnGc complex, its antigenicity, and its fusion machinery are poorly understood. Protective monoclonal antibodies against GnGc have the potential to be developed into therapeutics against hantaviral disease and are also great tools to elucidate the biology of the glycoprotein complex. Full Article
mode Romo1-Derived Antimicrobial Peptide Is a New Antimicrobial Agent against Multidrug-Resistant Bacteria in a Murine Model of Sepsis By mbio.asm.org Published On :: 2020-04-14T01:31:22-07:00 ABSTRACT To overcome increasing bacterial resistance to conventional antibiotics, many antimicrobial peptides (AMPs) derived from host defense proteins have been developed. However, there are considerable obstacles to their application to systemic infections because of their low bioavailability. In the present study, we developed an AMP derived from Romo1 (AMPR-11) that exhibits a broad spectrum of antimicrobial activity. AMPR-11 showed remarkable efficacy against sepsis-causing bacteria, including multidrug-resistant strains, with low toxicity in a murine model of sepsis after intravenous administration. It seems that AMPR-11 disrupts bacterial membranes by interacting with cardiolipin and lipid A. From the results of this study, we suggest that AMPR-11 is a new class of agent for overcoming low efficacy in the intravenous application of AMPs and is a promising candidate to overcome multidrug resistance. IMPORTANCE Abuse of antibiotics often leads to increase of multidrug-resistant (MDR) bacteria, which threatens the life of human beings. To overcome threat of antibiotic resistance, scientists are developing a novel class of antibiotics, antimicrobial peptides, that can eradicate MDR bacteria. Unfortunately, these antibiotics have mainly been developed to cure bacterial skin infections rather than others, such as life-threatening sepsis. Major pharmaceutical companies have tried to develop antiseptic drugs; however, they have not been successful. Here, we report that AMPR-11, the antimicrobial peptide (AMP) derived from mitochondrial nonselective channel Romo1, has antimicrobial activity against Gram-positive and Gram-negative bacteria comprising many clinically isolated MDR strains. Moreover, AMPR-11 increased the survival rate in a murine model of sepsis caused by MDR bacteria. We propose that AMPR-11 could be a novel antiseptic drug candidate with a broad antimicrobial spectrum to overcome MDR bacterial infection. Full Article