Zella Foysal

Photo: Steve Woods

The Bull shark (Carcharhinus leucas) also known as the Zambezi shark in South Africa, can be found in warm shallow waters throughout the world. Unlike most shark species, bull sharks have the ability to swim and survive in fresh water and can be found thousands of miles up rivers. Bull sharks owe their name to the sturdy form of their body and their unpredictable behavior.

Bull sharks are not very long sharks, but they tend to be very thick and stocky. The average size of an adult Bull shark is about 2.3meters in length and 130kg in weight, but specimens have been found up to 3.5meters long and weighing about 300kg. Like most sharks, they have counter shading meaning that they are grey on top and white on the bottom. Bull sharks have a broad, flat snout which is not very long. They have two triangular shaped dorsal fins, but no inter-dorsal ridge.

A key feature that separates bull sharks from most shark species is their rectal gland. The rectal gland is used for storing and excreting salt from the body, which allows them to control their salinity levels even when they are in freshwater environments.

Bull sharks are generally found in warm, shallow waters with temperatures around 32 degrees Celsius. They are found along the coasts of southern North America, Central America, South America, Africa, the Indian Ocean, as well as the Indo-Pacific near Southeast Asia. Specimens have been reported being seen nearly 2,000 miles up the Amazon and Mississippi rivers as well as being in golf course lakes after floods.

Due to their ability to feed in both freshwater and salt-water environments, bull sharks feed on a vast array of prey species. They feed on numerous bony fish, stingrays, other sharks, birds, turtles, crustaceans, and some mammals. They tend to hunt in murky waters because it allows them to sneak up on their prey. They’ve developed a unique hunting method; bull sharks first bump into their prey and then they bite. Pound for pound, Bull sharks have the strongest bite force compared to all shark species.

Bull sharks are viviparous, meaning that they give birth to free-swimming young. They have a gestation period of about one year and can give birth to one to twelve young per birthing. When they are born, adolescent bull sharks are around 65 to 75 centimeters long. They reach sexual maturity after around fifteen years and are about 270 centimeters long at this age.

Bull sharks are listed as Near Threatened by the International Union for Conservation of Nature (IUCN Red List). Bull sharks have long gestation periods, reach sexual maturity at a late age, and give birth to few young making them vulnerable to intense fishing and hunting pressures. They are harvested for their fins and meat, which are used to make the prized Chinese dish shark fin soup. Due to their role as apex predators, Bull sharks are very important to the environments they inhabit and are a necessity for a healthy reef and ecosystem.

Bull sharks are often found in shallow waters along coastal areas and rivers therefore it’s likely that there will be an encounter between these sharks and humans. There are many registered attacks on humans by this shark - according to the international Shark Attack file the bull shark is the third species with most attacks on humans. Only great white sharks and tiger sharks have more registered attacks on humans.

Originally written by Elizabeth Ward-Sing and edited by Isabelle Walter

#BullShark #Shark #CarcharhinusLeucas #FreshwaterShark #NearThreatened #IUCN #Conservation #SharkEducation

Now, let’s try to imagine a scenario. Suppose we have a stack of three disks. Our job is to move this stack from source A to destination C. How do we do this?

Before we can get there, let’s imagine there is an intermediate point B.

We can use B as a helper to finish this job. We are now ready to move on. Let’s go through each of the steps:

Boom! We have solved our problem.

You can see the animated image above for a better understanding.

Now, let’s try to build the algorithm to solve the problem. Wait, we have a new word here: “Algorithm”. What is that? Any idea? No problem, let’s see.

An algorithm is one of the most important concepts for a software developer. In fact, I think it’s not only important for software development or programming, but for everyone. Algorithms affect us in our everyday life. Let’s see how.

Suppose you work in an office. So every morning you do a series of tasks in a sequence: first you wake up, then you go to the washroom, eat breakfast, get prepared for the office, leave home, then you may take a taxi or bus or start walking towards the office and, after a certain time, you reach your office. You can say all those steps form an algorithm.

In simple terms, an algorithm is a set of tasks. I hope you haven’t forgotten those steps we did to move three disk stack from A to C. You can also say that those steps are the algorithm to solve the Tower of Hanoi problem.

If you take a look at those steps you can see that we were doing the same task multiple times — moving disks from one stack to another. We can call these steps inside steps recursion.

Recursion is calling the same action from that action. Just like the above picture.

So there is one rule for doing any recursive work: there must be a condition to stop that action executing. I hope you understand the basics about recursion.

Now, let’s try to build a procedure which helps us to solve the Tower of Hanoi problem. We are trying to build the solution using pseudocode. Pseudocode is a method of writing out computer code using the English language.

This is the skeleton of our solution. We take the total disks number as an argument. Then we need to pass source, intermediate place, and the destination so that we can understand the map which we will use to complete the job.

Now we need to find a terminal state. The terminal state is the state where we are not going to call this function anymore.

In our case, this would be our terminal state. Because when there will be one disk in our stack then it is easy to just do that final step and after that our task will be done. Don’t worry if it’s not clear to you. When we reach the end, this concept will be clearer.

Alright, we have found our terminal state point where we move our disk to the destination like this:

Now we call our function again by passing these arguments. In that case, we divide the stack of disks in two parts. The largest disk (nth disk) is in one part and all other (n-1) disks are in the second part. There we call the method two times for -(n-1).

As we said we pass total_disks_on_stack — 1 as an argument. And then again we move our disk like this:

After that we again call our method like this:

Let’s see our full pseudocode:

This is the tree for three disks:

This is the full code in Ruby:

Call tower(3, 'source','aux','dest')

Output:

It took seven steps for three disks to reach the destination. We call this a recursive method.

When we run code or an application in our machine it takes time — CPU cycles. But it’s not the same for every computer. For example, the processing time for a core i7 and a dual core are not the same. To solve this problem there is a concept used in computer science called time complexity.

The time complexity of algorithms is most commonly expressed using big O notation. It’s an asymptotic notation to represent the time complexity.

Now, the time required to move n disks is T(n). There are two recursive calls for (n-1). There is one constant time operation to move a disk from source to the destination, let this be m1. Therefore:

And

From these patterns — eq(2) to the last one — we can say that the time complexity of this algorithm is O(2^n) or O(a^n) where a is a constant greater than 1. So it has exponential time complexity. For the single increase in problem size, the time required is double the previous one. This is computationally very expensive. Most of the recursive programs take exponential time, and that is why it is very hard to write them iteratively.

After the explanation of time complexity analysis, I think you can guess now what this is…This is the calculation of space required in ram for running a code or application.

In our case, the space for the parameter for each call is independent of n, meaning it is constant. Let it be J. When we do the second recursive call, the first one is over. That means that we can reuse the space after finishing the first one. Hence:

So the space complexity is O(n).

After these analyses, we can see that time complexity of this algorithm is exponential but space complexity is linear.

1. Pay Attention and Adjust as You Go.
2. Learn to Cook.
3. Slowly Scale Back Fat Intake.
4. Add Back Carbs Slowly.
5. Visit the Mediterranean.
6. Avoid Previous Bad Habits.
7. Select Less Processed Foods.

From the above illustration, SFP port on SFP switch is a port type to cater for high-capacity long-reach networks It can be either connected to Ethernet copper

Not only is MF Doom talking about how he's a great rhymer , he's showing rhyming in rap music has not only evolved, it's gotten better

Built by the Peverel family in the 12th century, the castle became Crown property when the family line died out The Peverels were also founders of Peveril

1 Trapping Squirrels in the Attic Traps are a popular method It's recommended to use repeating-type traps that allow you to catch multiple

1. public class Characters
2. {
3. public static void main(String[] args) {
4. String str = "grass is greener on the other side";
5. int[] freq = new int[strlength()];
6. char minChar = strcharAt(0), maxChar = strcharAt(0);
7. int i, j, min, max;
8. //Converts given string into character array

From the creators of the popular VLC comes VLMC ( VideoLAN Movie Creator ), a non-linear video editing program that you can use to edit your

The application is executed using the mainloop method, which launches the main loop, in charge of managing all the events that the application receives, after an object of this type has been created.

The main window of the application was used in this first example. The main window is the application itself, the main element of our development, and without surrendering to the Anglo-Saxon language, we can admit that. In most of the examples, the root main is called the app. The main window of the application has a different name in the examples.

You can save the three lines of code in a file named Tk0py, open the terminal, and run it.

Check the qualities of the application you have created.

The internal Python help function will be used to obtain documentation on this class. Write the following statements in the interactive Python console.

The Tk class is instantiated without arguments.

The main application window is where the top-level Widget is created. Each instance has a different Tcl interpreter. Its prototype is one.

There is a list of methods common to tkinter.

The main window and the top level windows share methods. Some window managers don't support icons, others don't support groups.

We will be testing the methods as we need to.

The following statements can be added to the Tk 0.py file.

You can save the file with the name Tk-1.py and run it from the terminal.

Check how the application responds when you click the main mouse button on any of the elements, even if it's just a small portion.

In the previous topic we learned how to add the tkinter and ttk to our application, but we don't know how to add them to the main window. The topics of each widget are dedicated to deepen its use. The aim of this topic is to show how to add labels and buttons without going into depth, and to show how to use more than one widget in the examples of these notes.

To add a visual object to an application, you have to create it, and then use a method that places it in the part of the window that you want. To create an object in Python, it is necessary to call its constructor. To place it in a window, you can use its pack method, which will cover the whole unit. The two actions can be done in a single line.

The object of the Label class is what we need to add a label to the main window.

The master window is the main window if you identify it. In a complex application, memory is reserved for all the objects it uses and it must be developed keeping in mind that all the defined objects must be destroyed correctly before finishing the execution of the application.

The button is supposed to be used to press it. It can be similar to a label, but it is not just informative. Before you create a button, you must define the function.

To modify the text of a button, you need to know the button's name, its configuration method, and the text of its dictionary. It's necessary to have a variable created when it's identified.

We have two options to modify its text.

Either way.

If you have this information, you can recreate the application that we used to check if tkinter is installed on your computer.

You have recreated the application using the information that you have. Check the buttons and label of your app against the tkinter demo to see if they are the same. Recreate the application using the tkinter.Label and tkinter.Button.

To confirm the closing of the application, we need to associate the protocol with the main window.

The application will ask the user if he wants to close it with a messagebox.

It might be helpful to keep the Financial Indemnity Company claims address on hand. You can also call the Financial Indemnity Company phone number at (972) 690-5500.

• Visit the VAHAN e-service website.
• Click on “Know Your Vehicle Details”
• You will be required to enter the vehicle registration number.
• Click on the “Search Vehicle” option.
• It will show you the expiry date of the vehicle's insurance as well as other details.