Imagine the situation — you live in peace, nothing hurts and does not blush, wear glasses or lenses, or do not use anything and see perfectly — and you accidentally get an appointment with an ophthalmologist. For example, because of conscription into the army, because of pregnancy, or just for a dispensary examination. And suddenly you will find out that your retina is “full of holes” or stretched and is about to break.

And they recommend you to “sew it on”. And you doubt — and this is exactly what you need? And how safe is it? But nothing bothers — then why? Or maybe they want to earn money on me? And the first thing you start is to read posts on the Internet, what a “independent” expert like Google will say.

And in the future everything depends on your discipline and attention to your own health. You can get to the ophthalmologist-laser specialist, who will be the last resort, and he will do preventive laser coagulation.

Or «forget it» for everything and continue to live as before — nothing bothers you. What is the risk?

Why do you need a CRM system? Well, it’s at least more convenient than keeping your client database in Excel. Why do you need CRM with VoIP? If you have ever interacted offline, you know you cannot do it without telephony (orders, delivery, support etc.).

But what prevents 80% of companies from trying out a CRM tool? If prices is the matter, we are offering a free CRM system integrated with the phone system and free PBX.

To anticipate questions about installation difficulty, CRM setup and contact import doesn’t take more than 5 minutes.

Friends, after a break, we resume publications on vision and technology to restore it. The pause was connected with my workload of operations and participation in conferences: in the near future I will publish a review of the most interesting technical innovations in ophthalmology that were presented at them, and today we will talk about astigmatism.


Modern statistics depressing. More than half of the world's population suffers from visual impairment, the most common problems are myopia and hyperopia. But ophthalmologists often diagnose another disease, the name of which is unfamiliar to many. Astigmatism is a defect in the optical system of the eye when the sharpness of the image is asymmetric vertically and horizontally. And the parallel rays of light passing through the eye are focused not into a point, but into the “eight”. For a person, this means that the visibility of the image becomes unsharp, and this often applies to both distant and close objects. As a result, instead of a normal image, a person sees a distorted image, in which some lines are clear, others are blurred. An idea of ​​this can be obtained if you look at your distorted reflection in an oval teaspoon.

Ophthalmologists say that almost two thirds of the world's inhabitants face such a problem. But since the degree of astigmatism may be small, many people practically do not feel any discomfort. It is difficult for doctors to identify a clear list of common symptoms indicating that a patient has astigmatism. In each case, they will differ. In the very early stages, it is often confused with tired eyes.

However, quite a few people need special treatment or correction of this disorder with the help of glasses, contact lenses or even surgery.

We know that nobody is immune to glaucoma.

The number of patients with glaucoma worldwide more than 100 million (!) People. Nine out of ten blind people live in developing countries, and two thirds of them could be cured, they begin to be treated on time.

Glaucoma is the second cause of blindness after cataract — up to 20% of all cases of the disease end with it. Some people do not know about the disease. Glaucoma is often detected at stage 2–3 or at the last, 4th stage, when it is often impossible to help a person. In Russia, glaucoma has recently become the first cause of irreversible blindness, overtaking injury and vascular eye disease.

Despite a serious breakthrough in the understanding of many of the problems of glaucoma over the past few years, it must be admitted that so far no effective methods have been proposed to prevent the disease, its early (fairly cheap method!) Identification and treatment methods that are widely available.

The trouble is that the prevention of this disease, we have long ceased. Previously, after forty, all Soviet people were sure to measure eye pressure once a year. In clinics there were professional examination rooms, people with elevated intraocular pressure were referred to an ophthalmologist. And so revealed about half of patients with glaucoma. Now there is nothing like this. Saving patients was the work of the patients themselves (that is, drowning people).


Since the treatment of glaucoma is just as dangerous as caving — you climb into the dark, and when and what falls on your head, science is unknown. But if you don’t fall, you will drown or suffocate yourself — there are options. When you guess where you are, it will be too late. Let me start with a number of rules described below.

As a mathematician, it amazes me how much computing power fits on our mobile phones today. Like other «Gen Z» digital natives, I grew up watching people dream up and build technologies that have transformed our social lives, work lives and everything in between.

Yet in a time when humanity desperately needs innovation more than ever, the application of mobile technologies in the fight against COVID-19 has been weak and fragmented. We have technology literally at our fingertips that could be utilized to help us through this pandemic, but governments around the world have barely managed to develop even a contact tracing app.

Among the eye diseases are those that are especially dangerous. At first they are asymptomatic — nothing hurts, there are no complaints, they can “disguise” as other “mild” diseases and, most importantly, appear at any age and irrevocably “destroy” their eyesight.

Imagine if you left your left eye accidentally, but with your right, everything is “like a fog”! Read on the Internet how to help yourself or call your friends, and they — do not worry, blink. While they were waiting, it seemed that the fog was really over. This is how periods of anxiety recur, but at first there is little concern. And he (the murderer) began his insidious business. And as a rule, in both eyes, even if the second does not bother! And age is not an obstacle — children are also susceptible to this disease — 10% of children are blind from glaucoma.

Glaucoma is quite common in all countries — in 15% of cases of blindness, it is she who is the cause. This puts her in second place to the causes of incurable blindness!

And all is why — because the human brain very well «replaces» the dips in the field of view, if they arise gradually, adapt, and only when 30-40% of the optic nerve the feeling of «fog» begins. And all — hello, lost non-renewable!

This is a fourth article in the series of works (see also first one, second one, and third one) describing Machine Learning system based on Lattice Theory named 'VKF-system'. The program uses Markov chain algorithms to generate causes of the target property through computing random subset of similarities between some subsets of training objects. This article describes bitset representations of objects to compute these similarities as bit-wise multiplications of corresponding encodings. Objects with discrete attributes require some technique from Formal Concept Analysis. The case of objects with continuous attributes asks for logistic regression, entropy-based separation of their ranges into subintervals, and a presentation corresponding to the convex envelope for subintervals those similarity is computed.

Blockchain possesses incredible potential, that's why blockchain systems are considered as a paradise for data. In all these years, the discovery of Blockchain has been enjoyed for the introduction of distributed systems to secure data by cryptography.

From the creation of cryptocurrency to distributed ledger systems and mobile applications, this technology is being welcomed by every business vertical, and its adoption has become complimentary for companies. Moreover, its adoption can majorly be cherished by the healthcare industry.

A number of IT institutions are engaged in finding the most promising usage of blockchain technology in healthcare. Let's take a brief look at Blockchain adoption in 2020.

The Global Blockchain Adoption

In 2020, the worldwide spending on blockchain systems is USD 4.3 billion. As per Statista, the market of Blockchain will be worth 20 billion USD by the year 2025. Its most critical adoption can be seen in the healthcare industry, where this technology is being considered as the biggest game-changer.



The truth is that this technology has shown a path to distributed systems coupled with unmatched security measures That secure data in a chain of blocks infused with cryptographic locks. Top-notch level security and quality of not being tempered by any external entity boost its adoption in several instances.

What do you think, how many operations can be done on one eye? A clinical case of one of my patients confirms that more than 20 operations of various kinds are not the limit. Although, no doubt, this case is a record for Russia and the world of ophthalmology.

In 1978, everything was trivial — there was an 18 year old boy (let's call him “A”) who wanted to become a test pilot like his father. This was hampered by weak myopia of the right eye — only minus 1, it did not interfere with life, but the future pilot needed good vision. He decided to correct the optics of one eye by keratotomy — the old “manual” correction method at the Fedorov Institute (of course, through an acquaintance), but something went wrong. This was the first operation. Then four more in Russia, then seven more — in Switzerland. He did not become a pilot, but he became an oligarch, a man who manages serious business projects, but does not control the situation with his vision.

To me, «A» got completely disappointed in the world of ophthalmology, with 10% vision, the impossibility of correction by standard methods and high intraocular pressure. And it was a young 50-year-old businessman, successful in life (this is important — because not everything went further «like that» either). So — the next eight operations are mine. And although we expected that one or two would be enough — we had to go through almost total ophthalmic surgery — all possible types of operations.

By the way, instead of keratotomy, there would be a correction of SMILE (ReLEX SMILE) or, at least, Femto-LASIK — there wouldn’t be anything to write about — it’s impossible to do anything like that!

We understand that accountability starts with us,” says Sachin Kansal, the senior director of product management at Uber. With the vaccine for the Coronavirus still in the making, there is a need for collective responsibility to ensure global safety. Nations across the world are gradually lifting lockdowns, owing to the economic downfall. On the other hand, people are adapting to the ‘new’ normal. 

The American company Electronic Arts Inc (EA) has opened the source code of the games Command & Conquer: Tiberian Dawn and Command & Conquer: Red Alert publicly available. Several dozen errors were detected in the source code using the PVS-Studio analyzer, so, please, welcome the continuation of found defects review.

This is a third article in the series of works (see also first one and second one) describing Machine Learning system based on Lattice Theory named 'VKF-system'. It uses structural (lattice theoretic) approach to representing training objects and their fragments considered to be causes of the target property. The system computes these fragments as similarities between some subsets of training objects. There exists the algebraic theory for such representations, called Formal Concept Analysis (FCA). However the system uses randomized algorithms to remove drawbacks of the unrestricted approach. The details follow…

We have all been there  —  having a nice idea for a hackathon, hobby or a side project and having a burning desire to start coding as soon as possible. And how many possibilities (Heroku, Glitch and others) are there now to bootstrap your app and deploy it immediately.

Previous article describes a web server for Machine Learning system 'VKF' based on Lattice Theory. This paper is an attempt to explain details of using the CPython library directly. We reproduce working sessions of experiments on datasets 'Mushroom' and 'Wine Quality' from UCI Machine Learning repository. The structures of input files are discussed too.

Hello, community!

It is time for another Yii news issue. Both Yii 2 and Yii 3 are doing well.

I've finally updated the team page on the website to reflect the current state of things.

Konstantin Sirotkin is back and actively taking care of ElasticSearch Yii 2 extension.

Yii 3 main team was formed (actually happened late 2019). Likely you know the names because most were mentioned in previous Yii news issues.

Also, we have partially moved to GitHub actions. Experience is great so far, so we can definitely recommend that. We're adding phan static analysis
and running tests with Infection to make code quality even better.

We all know how hard it is to build an email sales list from scratch, especially for small companies. There left no options due to limited resources. In fact, many companies even buy preset profiled lists from the third party and send identical mass emails. It can put your business in a vulnerable position ascribed into the low quality of the email lists. However, there is a better way to build a highly targeted email list with email scraping tools.

Email scraping can help you collect email addresses shown publicly using a bot. What makes this great is that you have control over where to get the email lists from, and who can opt-in. Moreover, you don’t have to rely on the second-hand source. I profiled a list of best 10 email scraping tools for sales prospecting. Let’s take a look.

1. Zoominfo

A full-featured email scraping platform with a comprehensive database. You can directly search for titles and companies within their platform. It is more like a directory system that covers professionals in all industries with contact information. Email lists are the assets. That said, it comes with a price tag. It is worth to invest if you are looking for accurate sales leads. Zoominfo is an excellent option for enterprise-level sales prospects.

This is a continuation of story about using Data Science for finding an English teacher. If you have not read it yet - there is an opportunity to become familiar with it

Briefly  -  we had information about language teachers and tried to apply some basic ideas using pandas and our expectations. Unfortunately we got stuck on the third step, because there is not enough information for resolving our the last requirements  -  we need not more 3 candidates at the end.

We have been working on our current QA process for about two years, and we still keep improving it. This process may seem obvious, but when we started to implement it in a new team that consisted entirely of new developers, we realized that it was difficult to do right away. Many people are used to working differently and need to make a lot of changes at once to switch, which is difficult. At the same time, it is ill-advised to implement this process in parts, because it can negatively affect the quality.

What do we do? We need to do preliminary preparation for each block of the development process: task decomposition, evaluation and planning, development itself, investigative testing, and release. This preparation does not consist of simply throwing old parts out of the process but of their adequate replacement, which increases quality.

In this article, I will talk in detail about our testing process at each stage of creating a new feature and also about the introduced changes that have increased the quality and speed of development.

Not so long ago, a landmark event has happened: PVS-Studio appeared in Compiler Explorer! Now you can quickly and easily analyze the code for errors right on the godbolt.org site (Compiler Explorer). This feature opens up a large number of new possibilities – from quenching curiosity about the analyzer's abilities to being able to quickly share check results with a friend. This article will cover the topic on how to use these features. Caution – large GIFs!

Nowadays most people identify Machine Learning with training of various kinds of neural networks. At the beginning there were fully connected networks, then convolutional and recurrent networks replace them, now there exist a quite exotic variants of networks such that GAN and LTSM networks.

Their training requires constantly increasing volume of samples, and they also do not be able to explain why a particular decision was made. Structural approaches to Machine Learning avoiding these drawbacks exist, the software implementation of one of which is described in the article. This is an English translation of original post by the author.