How does SolrCloud ensure that replicated data remains consistent? How does Solr avoid data loss when hardware inevitably fails? In this talk, we will cover how Solr addresses failures and what recovery steps the cluster can automatically perform.
Lambda Architecture with Spark, Spark Streaming, Kafka, Cassandra, Akka and S...Helena Edelson
Regardless of the meaning we are searching for over our vast amounts of data, whether we are in science, finance, technology, energy, health care…, we all share the same problems that must be solved: How do we achieve that? What technologies best support the requirements? This talk is about how to leverage fast access to historical data with real time streaming data for predictive modeling for lambda architecture with Spark Streaming, Kafka, Cassandra, Akka and Scala. Efficient Stream Computation, Composable Data Pipelines, Data Locality, Cassandra data model and low latency, Kafka producers and HTTP endpoints as akka actors...
ProxySQL - High Performance and HA Proxy for MySQLRené Cannaò
High Availability proxy designed to solve real issues of MySQL setups from small to very large production environments.
Presentation at Percona Live Amsterdam 2015
Lambda Architecture with Spark, Spark Streaming, Kafka, Cassandra, Akka and S...Helena Edelson
Regardless of the meaning we are searching for over our vast amounts of data, whether we are in science, finance, technology, energy, health care…, we all share the same problems that must be solved: How do we achieve that? What technologies best support the requirements? This talk is about how to leverage fast access to historical data with real time streaming data for predictive modeling for lambda architecture with Spark Streaming, Kafka, Cassandra, Akka and Scala. Efficient Stream Computation, Composable Data Pipelines, Data Locality, Cassandra data model and low latency, Kafka producers and HTTP endpoints as akka actors...
ProxySQL - High Performance and HA Proxy for MySQLRené Cannaò
High Availability proxy designed to solve real issues of MySQL setups from small to very large production environments.
Presentation at Percona Live Amsterdam 2015
Staying Ahead of the Curve with Spring and Cassandra 4VMware Tanzu
SpringOne 2020
Staying Ahead of the Curve with Spring and Cassandra 4
Mark Paluch, Spring Data Project Lead at VMware
Alexandre Dutra, Technical Manager at DataStax
MySQL Group Replication - HandsOn TutorialKenny Gryp
During this tutorial, attendees have their hands on virtual machines and migrate standard Master - Slave architecture to the new MySQL native Group Replication.
After explaining briefly what is group replication and how this is important for MySQL HA architecture. We will cover how to verify the workload and the scheme to how GR can be used and configured.
Then we will go trough the migration steps with minimal impact on the live system.
Basic administration tasks are covered such as add/remove a node from the cluster. We also play with performance_schema to monitor our Group Replication cluster and understand how to control it.
Apache Phoenix’s relational database view over Apache HBase delivers a powerful tool which enables users and developers to quickly and efficiently access their data using SQL. However, Phoenix only provides a Java client, in the form of a JDBC driver, which limits Phoenix access to JVM-based applications. The Phoenix QueryServer is a standalone service which provides the building blocks to use Phoenix from any language, not just those running in a JVM. This talk will serve as a general purpose introduction to the Phoenix QueryServer and how it complements existing Apache Phoenix applications. Topics covered will range from design and architecture of the technology to deployment strategies of the QueryServer in production environments. We will also include explorations of the new use cases enabled by this technology like integrations with non-JVM based languages (Ruby, Python or .NET) and the high-level abstractions made possible by these basic language integrations.
When does InnoDB lock a row? Multiple rows? Why would it lock a gap? How do transactions affect these scenarios? Locking is one of the more opaque features of MySQL, but it’s very important for both developers and DBA’s to understand if they want their applications to work with high performance and concurrency. This is a creative presentation to illustrate the scenarios for locking in InnoDB and make these scenarios easier to visualize. I'll cover: key locks, table locks, gap locks, shared locks, exclusive locks, intention locks, insert locks, auto-inc locks, and also conditions for deadlocks.
Static Membership: Rebalance Strategy Designed for the Cloud (Boyang Chen,Con...confluent
In this presentation, we introduce static membership (KIP-345) and share the story of adopting it at Pinterest. The static membership aims to improve the availability of stream applications, consumer groups and other applications built on top of it. The original rebalance protocol relies on the group coordinator to allocate entity ids to group members. These generated ids are ephemeral and will change when members restart and rejoin. For consumer based apps, this "dynamic membership" can cause a large percentage of tasks re-assigned to different instances during administrative operations such as code deploys, configuration updates and periodic restarts. For large state applications, shuffled tasks need a long time to recover their local states before processing and cause applications to be partially or entirely unavailable. At Pinterest, the group membership is stable between administrative operations. Motivated by this observation, we modified the Kafka's group management protocol allowing group members to provide persistent entity ids. Group membership remains unchanged based on those ids, thus no rebalance will be triggered. We can conveniently leverage Kubernetes or other cloud management frameworks to provide entity ids. By adopting static membership to the realtime infrastructure at Pinterest, applications resume processing only a few seconds after administrative operations finish. Previously with dynamic membership, it can take more than 30 minutes before applications resume. The talk is organized as follows: we first review Kafka's group management protocol and demonstrate high availability use cases that dynamic membership is unable to support. Then we share the design and adoption story of static membership. At the end, we do a live demo to show the impact of static membership.
Understanding SQL Trace, TKPROF and Execution Plan for beginnersCarlos Sierra
The three fundamental steps of SQL Tuning are: 1) Diagnostics Collection; 2) Root Cause Analysis (RCA); and 3) Remediation. This introductory session on SQL Tuning is for novice DBAs and Developers that are required to investigate a piece of an application performing poorly.
On this session participants will learn about producing a SQL Trace then a summary TKPROF report. A sample TKPROF is navigated with the audience, where the trivial and the no so trivial is exposed and explain. Execution Plans are also navigated and explained, so participants can later untangle complex Execution Plans and start diagnosing SQL performing badly.
This session encourages participants to ask all kind of questions that could be potential road-blocks for deeper understanding of how to address a SQL performing poorly.
This presentation is designed to provide a comprehensive overview of the top 10 features of MySQL 8.0, explaining why they are advantageous and how they will improve the MySQL experience for users. Furthermore, this presentation will provide a timeline for users to plan for and upgrade from MySQL 5.7, which will reach its end of life by October 2023.
Recording available YouTube Channel: https://www.youtube.com/c/Mydbops?app=desktop
PostgreSQL worst practices, version PGConf.US 2017 by Ilya KosmodemianskyPostgreSQL-Consulting
This talk is prepared as a bunch of slides, where each slide describes a really bad way people can screw up their PostgreSQL database and provides a weight - how frequently I saw that kind of problem. Right before the talk I will reshuffle the deck to draw twenty random slides and explain you why such practices are bad and how to avoid running into them.
Staying Ahead of the Curve with Spring and Cassandra 4VMware Tanzu
SpringOne 2020
Staying Ahead of the Curve with Spring and Cassandra 4
Mark Paluch, Spring Data Project Lead at VMware
Alexandre Dutra, Technical Manager at DataStax
MySQL Group Replication - HandsOn TutorialKenny Gryp
During this tutorial, attendees have their hands on virtual machines and migrate standard Master - Slave architecture to the new MySQL native Group Replication.
After explaining briefly what is group replication and how this is important for MySQL HA architecture. We will cover how to verify the workload and the scheme to how GR can be used and configured.
Then we will go trough the migration steps with minimal impact on the live system.
Basic administration tasks are covered such as add/remove a node from the cluster. We also play with performance_schema to monitor our Group Replication cluster and understand how to control it.
Apache Phoenix’s relational database view over Apache HBase delivers a powerful tool which enables users and developers to quickly and efficiently access their data using SQL. However, Phoenix only provides a Java client, in the form of a JDBC driver, which limits Phoenix access to JVM-based applications. The Phoenix QueryServer is a standalone service which provides the building blocks to use Phoenix from any language, not just those running in a JVM. This talk will serve as a general purpose introduction to the Phoenix QueryServer and how it complements existing Apache Phoenix applications. Topics covered will range from design and architecture of the technology to deployment strategies of the QueryServer in production environments. We will also include explorations of the new use cases enabled by this technology like integrations with non-JVM based languages (Ruby, Python or .NET) and the high-level abstractions made possible by these basic language integrations.
When does InnoDB lock a row? Multiple rows? Why would it lock a gap? How do transactions affect these scenarios? Locking is one of the more opaque features of MySQL, but it’s very important for both developers and DBA’s to understand if they want their applications to work with high performance and concurrency. This is a creative presentation to illustrate the scenarios for locking in InnoDB and make these scenarios easier to visualize. I'll cover: key locks, table locks, gap locks, shared locks, exclusive locks, intention locks, insert locks, auto-inc locks, and also conditions for deadlocks.
Static Membership: Rebalance Strategy Designed for the Cloud (Boyang Chen,Con...confluent
In this presentation, we introduce static membership (KIP-345) and share the story of adopting it at Pinterest. The static membership aims to improve the availability of stream applications, consumer groups and other applications built on top of it. The original rebalance protocol relies on the group coordinator to allocate entity ids to group members. These generated ids are ephemeral and will change when members restart and rejoin. For consumer based apps, this "dynamic membership" can cause a large percentage of tasks re-assigned to different instances during administrative operations such as code deploys, configuration updates and periodic restarts. For large state applications, shuffled tasks need a long time to recover their local states before processing and cause applications to be partially or entirely unavailable. At Pinterest, the group membership is stable between administrative operations. Motivated by this observation, we modified the Kafka's group management protocol allowing group members to provide persistent entity ids. Group membership remains unchanged based on those ids, thus no rebalance will be triggered. We can conveniently leverage Kubernetes or other cloud management frameworks to provide entity ids. By adopting static membership to the realtime infrastructure at Pinterest, applications resume processing only a few seconds after administrative operations finish. Previously with dynamic membership, it can take more than 30 minutes before applications resume. The talk is organized as follows: we first review Kafka's group management protocol and demonstrate high availability use cases that dynamic membership is unable to support. Then we share the design and adoption story of static membership. At the end, we do a live demo to show the impact of static membership.
Understanding SQL Trace, TKPROF and Execution Plan for beginnersCarlos Sierra
The three fundamental steps of SQL Tuning are: 1) Diagnostics Collection; 2) Root Cause Analysis (RCA); and 3) Remediation. This introductory session on SQL Tuning is for novice DBAs and Developers that are required to investigate a piece of an application performing poorly.
On this session participants will learn about producing a SQL Trace then a summary TKPROF report. A sample TKPROF is navigated with the audience, where the trivial and the no so trivial is exposed and explain. Execution Plans are also navigated and explained, so participants can later untangle complex Execution Plans and start diagnosing SQL performing badly.
This session encourages participants to ask all kind of questions that could be potential road-blocks for deeper understanding of how to address a SQL performing poorly.
This presentation is designed to provide a comprehensive overview of the top 10 features of MySQL 8.0, explaining why they are advantageous and how they will improve the MySQL experience for users. Furthermore, this presentation will provide a timeline for users to plan for and upgrade from MySQL 5.7, which will reach its end of life by October 2023.
Recording available YouTube Channel: https://www.youtube.com/c/Mydbops?app=desktop
PostgreSQL worst practices, version PGConf.US 2017 by Ilya KosmodemianskyPostgreSQL-Consulting
This talk is prepared as a bunch of slides, where each slide describes a really bad way people can screw up their PostgreSQL database and provides a weight - how frequently I saw that kind of problem. Right before the talk I will reshuffle the deck to draw twenty random slides and explain you why such practices are bad and how to avoid running into them.
Securing the Data Hub--Protecting your Customer IP (Technical Workshop)Cloudera, Inc.
Your data is your IP and its security is paramount. The last thing you want is for your data to become a target for threats. This workshop will focus on the realities of protecting your customer’s IP from external and internal threats with battle hardened technologies and methodologies. Another key concept that will be examined is the connection of people, processes and technology. In addition, the session will take a look at authentication and authorisation, auditing and data lineage as well as the different groups required to play a part in the modern data hub. We will also look at how to produce high impact operation reports from Cloudera’s RecordService a new core security layer that centrally enforces fine-grained access control policy, which helps close the feedback loop to ensure awareness of security as a living entity within your organisation.
Hadoop Operations for Production Systems (Strata NYC)Kathleen Ting
Hadoop is emerging as the standard for big data processing and analytics. However, as usage of the Hadoop clusters grow, so do the demands of managing and monitoring these systems.
In this full-day Strata Hadoop World tutorial, attendees will get an overview of all phases for successfully managing Hadoop clusters, with an emphasis on production systems — from installation, to configuration management, service monitoring, troubleshooting and support integration.
We will review tooling capabilities and highlight the ones that have been most helpful to users, and share some of the lessons learned and best practices from users who depend on Hadoop as a business-critical system.
Introduction to Apache ZooKeeper | Big Data Hadoop Spark Tutorial | CloudxLabCloudxLab
Big Data with Hadoop & Spark Training: http://bit.ly/2kvXlPd
This CloudxLab Introduction to Apache ZooKeeper tutorial helps you to understand ZooKeeper in detail. Below are the topics covered in this tutorial:
1) Data Model
2) Znode Types
3) Persistent Znode
4) Sequential Znode
5) Architecture
6) Election & Majority Demo
7) Why Do We Need Majority?
8) Guarantees - Sequential consistency, Atomicity, Single system image, Durability, Timeliness
9) ZooKeeper APIs
10) Watches & Triggers
11) ACLs - Access Control Lists
12) Usecases
13) When Not to Use ZooKeeper
So we're running Apache ZooKeeper. Now What? By Camille Fournier Hakka Labs
The ZooKeeper framework was originally built at Yahoo! to make it easy for the company’s applications to access configuration information in a robust and easy-to-understand way, but it has since grown to offer a lot of features that help coordinate work across distributed clusters. Apache Zookeeper became a de-facto standard for coordination service and used by Storm, Hadoop, HBase, ElasticSearch and other distributed computing frameworks.
Sqoop Meetup in NYC 11/7/11 - process from finding a Sqoop bug, filing a
jira, coding a patch, submitting it for review, revising accordingly,
and finally to ship it '+1' approval
February 2016 HUG: Apache Kudu (incubating): New Apache Hadoop Storage for Fa...Yahoo Developer Network
Over the past several years, the Hadoop ecosystem has made great strides in its real-time access capabilities, narrowing the gap compared to traditional database technologies. With systems such as Impala and Apache Spark, analysts can now run complex queries or jobs over large datasets within a matter of seconds. With systems such as Apache HBase and Apache Phoenix, applications can achieve millisecond-scale random access to arbitrarily-sized datasets. Despite these advances, some important gaps remain that prevent many applications from transitioning to Hadoop-based architectures. Users are often caught between a rock and a hard place: columnar formats such as Apache Parquet offer extremely fast scan rates for analytics, but little to no ability for real-time modification or row-by-row indexed access. Online systems such as HBase offer very fast random access, but scan rates that are too slow for large scale data warehousing workloads. This talk will investigate the trade-offs between real-time transactional access and fast analytic performance from the perspective of storage engine internals. It will also describe Kudu, the new addition to the open source Hadoop ecosystem with out-of-the-box integration with Apache Spark, that fills the gap described above to provide a new option to achieve fast scans and fast random access from a single API.
Speakers:
David Alves. Software engineer at Cloudera working on the Kudu team, and a PhD student at UT Austin. David is a committer at the Apache Software Foundation and has contributed to several open source projects, including Apache Cassandra and Apache Drill.
The popular R package dplyr provides a consistent grammar for data manipulation that can abstract over diverse data sources. Ian Cook shows how you can use dplyr to query large-scale data using different processing engines including Spark and Impala. He demonstrates the R package sparklyr (from RStudio) and the new R package implyr (from Cloudera) and shares tips for making dplyr code portable.
Whether you are developing a greenfield data project or migrating a legacy system,
there are many critical design decisions to be made. Often, it is advantageous to not only
consider immediate requirements, but also the future requirements and technologies you may
want to support. Your project may start out supporting batch analytics with the vision of adding
realtime support. Or your data pipeline may feed data to one technology today, but tomorrow
an entirely new system needs to be integrated. Apache Kafka can help decouple these
decisions and provide a flexible core to your data architecture. This talk will show how building
Kafka into your pipeline can provide the flexibility to experiment, evolve and grow. It will also
cover a brief overview of Kafka, its architecture, and terminology.
Transitioning From SQL Server to MySQL - Presentation from Percona Live 2016Dylan Butler
What if you were asked to support a database platform that you had never worked with before? First you would probably say no, but after you lost that fight, then what? That is exactly how I came to support MySQL. Over the last year my team has worked to learn MySQL, architect a production environment, and figure out how to support it alongside our other platforms (Microsoft SQL Server and Oracle). Along the way, I have also come to appreciate the unique offering of this platform and see it as an important part of our environment going forward.
To make things even more challenging, our first MySQL databases were the backend for a critical, web based application that needed to be highly available across multiple data centers. This meant that we did not have the luxury of standing up a simpler environment to start with and building confidence there. Our final architecture ended up using a five node Percona XtraDB Cluster spread across three data centers.
This session will focus on lessons learned along the way, as well as challenges related to supporting more than one database platforms. It should be interesting to anyone who is new to MySQL, anyone who is being asked to support more than one database platform, or anyone who wants to see how an outsider views the platform.
Ingest and Stream Processing - What will you choose?Pat Patterson
Pat Patterson and Ted Malaska talk about current and emerging technologies. They evaluate each and understand how they are useful in solving problems related to large scale data processing, joining and combining streams. They also talk about the various ways of achieving "at least once" and "exactly once" processing and how we can make sure that data is processed in a timely fashion.
Similar to Solr consistency and recovery internals (20)
Cloudera Data Impact Awards 2021 - Finalists Cloudera, Inc.
This annual program recognizes organizations who are moving swiftly towards the future and building innovative solutions by making what was impossible yesterday, possible today.
The winning organizations' implementations demonstrate outstanding achievements in fulfilling their mission, technical advancement, and overall impact.
The 2021 Data Impact Awards recognize organizations' achievements with the Cloudera Data Platform in seven categories:
Data Lifecycle Connection
Data for Enterprise AI
Cloud Innovation
Security & Governance Leadership
People First
Data for Good
Industry Transformation
2020 Cloudera Data Impact Awards FinalistsCloudera, Inc.
Cloudera is proud to present the 2020 Data Impact Awards Finalists. This annual program recognizes organizations running the Cloudera platform for the applications they've built and the impact their data projects have on their organizations, their industries, and the world. Nominations were evaluated by a panel of independent thought-leaders and expert industry analysts, who then selected the finalists and winners. Winners exemplify the most-cutting edge data projects and represent innovation and leadership in their respective industries.
Machine Learning with Limited Labeled Data 4/3/19Cloudera, Inc.
Cloudera Fast Forward Labs’ latest research report and prototype explore learning with limited labeled data. This capability relaxes the stringent labeled data requirement in supervised machine learning and opens up new product possibilities. It is industry invariant, addresses the labeling pain point and enables applications to be built faster and more efficiently.
Data Driven With the Cloudera Modern Data Warehouse 3.19.19Cloudera, Inc.
In this session, we will cover how to move beyond structured, curated reports based on known questions on known data, to an ad-hoc exploration of all data to optimize business processes and into the unknown questions on unknown data, where machine learning and statistically motivated predictive analytics are shaping business strategy.
Introducing Cloudera DataFlow (CDF) 2.13.19Cloudera, Inc.
Watch this webinar to understand how Hortonworks DataFlow (HDF) has evolved into the new Cloudera DataFlow (CDF). Learn about key capabilities that CDF delivers such as -
-Powerful data ingestion powered by Apache NiFi
-Edge data collection by Apache MiNiFi
-IoT-scale streaming data processing with Apache Kafka
-Enterprise services to offer unified security and governance from edge-to-enterprise
Introducing Cloudera Data Science Workbench for HDP 2.12.19Cloudera, Inc.
Cloudera’s Data Science Workbench (CDSW) is available for Hortonworks Data Platform (HDP) clusters for secure, collaborative data science at scale. During this webinar, we provide an introductory tour of CDSW and a demonstration of a machine learning workflow using CDSW on HDP.
Shortening the Sales Cycle with a Modern Data Warehouse 1.30.19Cloudera, Inc.
Join Cloudera as we outline how we use Cloudera technology to strengthen sales engagement, minimize marketing waste, and empower line of business leaders to drive successful outcomes.
Leveraging the cloud for analytics and machine learning 1.29.19Cloudera, Inc.
Learn how organizations are deriving unique customer insights, improving product and services efficiency, and reducing business risk with a modern big data architecture powered by Cloudera on Azure. In this webinar, you see how fast and easy it is to deploy a modern data management platform—in your cloud, on your terms.
Modernizing the Legacy Data Warehouse – What, Why, and How 1.23.19Cloudera, Inc.
Join us to learn about the challenges of legacy data warehousing, the goals of modern data warehousing, and the design patterns and frameworks that help to accelerate modernization efforts.
Leveraging the Cloud for Big Data Analytics 12.11.18Cloudera, Inc.
Learn how organizations are deriving unique customer insights, improving product and services efficiency, and reducing business risk with a modern big data architecture powered by Cloudera on AWS. In this webinar, you see how fast and easy it is to deploy a modern data management platform—in your cloud, on your terms.
Explore new trends and use cases in data warehousing including exploration and discovery, self-service ad-hoc analysis, predictive analytics and more ways to get deeper business insight. Modern Data Warehousing Fundamentals will show how to modernize your data warehouse architecture and infrastructure for benefits to both traditional analytics practitioners and data scientists and engineers.
Explore new trends and use cases in data warehousing including exploration and discovery, self-service ad-hoc analysis, predictive analytics and more ways to get deeper business insight. Modern Data Warehousing Fundamentals will show how to modernize your data warehouse architecture and infrastructure for benefits to both traditional analytics practitioners and data scientists and engineers.
Explore new trends and use cases in data warehousing including exploration and discovery, self-service ad-hoc analysis, predictive analytics and more ways to get deeper business insight. Modern Data Warehousing Fundamentals will show how to modernize your data warehouse architecture and infrastructure for benefits to both traditional analytics practitioners and data scientists and engineers.
Extending Cloudera SDX beyond the PlatformCloudera, Inc.
Cloudera SDX is by no means no restricted to just the platform; it extends well beyond. In this webinar, we show you how Bardess Group’s Zero2Hero solution leverages the shared data experience to coordinate Cloudera, Trifacta, and Qlik to deliver complete customer insight.
Federated Learning: ML with Privacy on the Edge 11.15.18Cloudera, Inc.
Join Cloudera Fast Forward Labs Research Engineer, Mike Lee Williams, to hear about their latest research report and prototype on Federated Learning. Learn more about what it is, when it’s applicable, how it works, and the current landscape of tools and libraries.
Analyst Webinar: Doing a 180 on Customer 360Cloudera, Inc.
451 Research Analyst Sheryl Kingstone, and Cloudera’s Steve Totman recently discussed how a growing number of organizations are replacing legacy Customer 360 systems with Customer Insights Platforms.
Build a modern platform for anti-money laundering 9.19.18Cloudera, Inc.
In this webinar, you will learn how Cloudera and BAH riskCanvas can help you build a modern AML platform that reduces false positive rates, investigation costs, technology sprawl, and regulatory risk.
Introducing the data science sandbox as a service 8.30.18Cloudera, Inc.
How can companies integrate data science into their businesses more effectively? Watch this recorded webinar and demonstration to hear more about operationalizing data science with Cloudera Data Science Workbench on Cazena’s fully-managed cloud platform.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.