Connect with us

Science

Gregor Johan Mendel

Gregor Johan Mendel Biography
Google

Gregor Johan Mendel Biography

Gregor Mendel was an Augustinian monk, naturalist, and Catholic who formulated the laws of biological inheritance which bear his name, through work with various types of peas. The experiments that he carried out on the inheritance in plants are part of the point of origin of modern genetics.

He was born on July 20, 1822, in the town of Heinzendorf located north of Moravia, the Czech Republic, son of Gregor Mendel, his father, who was a veteran of the Napoleonic wars and his mother Rosine Mendel, daughter of a humble gardener. He was baptized as Johann Mendel. However, on October 9, 1843, he took the name of his father (Gregor) when he became an Augustinian friar in the convent of Augustinians of Brno. After almost 4 years of preparation in the monastery, Mendel was appointed priest on August 6, 1847.

Mendel was always interested in being a teacher, so in 1851 he traveled to Vienna where he did a Ph.D. in mathematics and science. A year later, Mendel began his teaching career as substitute professor at the Royal School of Brünn. However, in 1868, he would definitively abandon his work as professor and scientific researcher since he was appointed Abbot of the convent of Augustinians.

Mendel began his work on genetic experiments in 1856 when he made crosses with pea seeds, which resulted in different styles to the crusaders and some identical to them. He managed to find characters that expressed themselves in different ways according to the allele, whether recessive or dominant. He named dominant alleles to those that determine the effect of a gene and to the recessive ones by the characteristic of having no genetic effect on a heterozygous phenotype. The result of these experiments allowed him to discover in 1865 the 3 laws of inheritance, with which it is possible to discover the mechanisms of inheritance. The three laws that he established, state the following:

First law or principle of uniformity: “When two species of pure race cross, the descendants are all equal.”

Second law or principle of segregation: “Some individuals have the ability to transmit a character, even if they do not manifest themselves in them.” This explains that the individuals of a second generation, the descendants are divided into 4 and of which 3 inherit the dominant character and one inherits the recessive character.

Third law or principle of the independent combination: This law indicates everything related to the poly hybrid crossing, which indicates that, if the two varieties from which they split, differ from each other in 2 or more characters, each character is transmitted independently from the others.

On February 8 and March 8 of the year 1865, Mendel made two respective presentations of his work at the meetings of the Natural History Society of Brünn and subsequently published them as experiments on the hybridization of plants in 1866, results that were ignored and could not be understood and explained until 30 years later.

Gregor Mendel also carried out work in beekeeping with the aim of investigating the biological interest that bees have with flowers, which he carried out in the last 10 years of his life and with which he obtained several recognitions:

In 1871 he was an active member of the beekeeping society of Brünn and for what he was appointed president sometime later.

Between September 12 and 14, 1871, he was delegated by the beekeeping association of Brünn to attend, together with his friend Ziwansky, the German Beekeeping Congress held in Kiel.

Gregor Johan Mendel died on January 6, 1884, at the age of 62 due to chronic nephritis. Mendel will always be recognized by the broad legacy he left and by his magnificent discovery that today allows us to understand the transmission of genetic characteristics from parents to children.

Advertisement

Science

The history of the atom

The history of the atom
Public domain

The history of the atom

The history of the atom begins 450 years before Christ with the assertions postulated by the Greek philosopher Democritus of Abdera. The philosopher was interested in the discovery of essential substances that contain all substances. He claimed that matter could be indefinitely divided into increasingly smaller particles until reaching the most indivisible point of that matter, which Democritus called atoms, a word that in Greek means inseparable. So, matter was composed of atoms and these were inseparable, so Democritus made a distinction between previous thinkers, who named atomic elements to elements such as water, air, and fire. Democritus claimed that these were not atoms in themselves, but were composed of thousands of them.

In short, Democritus supposed that all matter is composed of solid, indivisible and invisible to the human eye particles, the famous atoms. Although this philosopher interested in physical and chemical processes never had a true proof that proved the existence of the atom. We can affirm that he was the first person to talk about this and consolidate an atomist conception, known today as the Discontinuity of Matter, generating a long debate with the passing of the centuries.

The philosopher Leucippus of Miletus based his idea of the rational origin of the universe on the atom, claiming that the universe was made up of thousands of indivisible particles that came together after an event similar to a whirlwind. Epicurus of Samos, a philosopher from Athens, with his doctrine of nature, claimed, reworking Democritus’s version, that the formation of the universe could have responded to a process of chance, in other words, the probability that atoms would suffer deviations in their trajectory, colliding with each other.

It took several centuries for John Dalton, known as the father of atomic theory, to be born in 1776. He was born in the United Kingdom, specifically in Cumbria. From the age of 12, he showed his intelligence. As a young man, he was interested in meteorology and from there his attraction to certain chemical phenomena exploded. Dalton’s postulates marked a major change in knowledge about atoms and their behavior.

In that sense, the scientist claimed that matter is composed of indivisible atoms, this statement was not very new. But, in addition, he added that atoms have an immutable character, that is, they can never be transformed into each other, what has variable value are chemical combinations because they are made up of identical molecules and these in turn by atoms. Thanks to an endless number of experiments carried out by Dalton, the Dalton Atomic Theory was established.

The mentioned theory helped to calculate the atomic weight of the elements, such as the gaseous elements. He discovered the atomic masses of several elements by relating them to the mass of hydrogen. These discoveries were presented on October 21, 1803 during a conference at the Manchester Literary and Philosophical Society. Later, the disquisitions were reflected in his famous book A New System of Chemical Philosophy, published in 1808.

In this text, the following general statements can be highlighted: matter is composed of atomic particles, indivisible and indestructible, atoms of the same element are equal, as well as their weight and qualities, atoms do not divide even when they combine through chemical reactions, atoms of different elements can combine and form compound atoms, finally, chemical compounds are born from the union of atoms of two or more different elements. Many of Dalton’s statements were challenged or reaffirmed.

In the future, Michael Faraday reformulated several of Dalton’s proposals. In 1883, he discovered that the flow of electric current from one substance to another produces certain chemical changes, indicating the existence of a relationship between electricity and matter, ensuring that atoms must have an electric structure that supplies the appropriate amount of electric current to the weight of the decomposed chemical substance.

En el año de 1906 sale a la luz el Modelo Atómico de Thomson, que claramente invalidaba el anterior Modelo Atómico de Dalton ya que este no reflexionaba sobre la estructura interna del átomo. El físico británico Joseph John Thomson se valió del uso de los rayos catódicos dispuestos en un tubo de vacío que eran desviados al aplicar un campo magnético para obtener las pruebas para dar a luz este modelo.

The Thomson atomic model postulates that: The atom has negatively charged electrons embedded in a sphere of positive charge, these electrons are uniformly distributed throughout the atom, the atom is neutral so that the negative charges of the electrons are offset by the positive charge, the electrons can be extracted from the atom of any substance. Thus, Thomson represented the atom with a static model, in which the electrons were fixed within the positive mass, this model was approved by the scientific community because it allowed to explain qualitatively phenomena such as the emission of light by atoms, although later facts modified this hypothesis.

Ernest Rutherford was the one who modified Thomson’s model, who in 1911 considered that in the central nucleus of the atom there is the positive charge and mass; while around there are electrons spinning at high speed. On the other hand, he discovered that the nucleus has a crust and a nucleus, the electrons that spin do so in the crust of the atom around the nucleus; this region is small and is located in the center of the atom that has the positive charge.

Just two years later, Niels Bohr, studying Rutherford’s model disciplinely, deepened the way in which electrons were kept under a stable orbit around the nucleus without radiating energy, also thanks to the quantum number n, he was able to assure that first: there is a distance between the orbit and the nucleus; second that not all electrons circulate through all orbits and third he calculated the radius of the orbit. Bohr also explained why atoms showed characteristic emission spectra and how electrons can emit or absorb energy during jumps from one orbit to another. Shortly thereafter, the Sommerfeld model came out, based on Bohr’s, formulating contributions to relativistic mechanics indicating that electrons travel at speeds close to that of light. It can also be highlighted that for Sommerfeld, the electron is basically an electric current. In 1924, the Schrödinger model, formulated by Erwin Schrödinger, came to light, which as an innovation takes into account the four quantum numbers: n, i, m, s. to affirm that in an atom there are no electrons with the four quantum numbers equal.

In the 60s American physicists Murray Gell-Mann and Georg Zweig detected a subatomic particle called a quark. In the 21st century a team of scientists carried out experiments in the Large Hadron Collider found the pentaquarks. This discovery of the subatomic particle helps to better understand the constitution of ordinary matter, neutrons and protons.

Continue Reading

Science

The history of biology

history of biology
CC BY-NC 4.0, Midjourney

The history of biology

The origin of biology dates back to Greek philosophy, when the natural sciences were introduced. Hippocrates was the first to give a biological concept of life, and Aristotle is recognized as the first to classify animals. Aristotle was one of the greatest naturalists of ancient times and his greatest interest was living nature. He was the first great biologist of Europe and formulated the principle that all organisms are adapted to the environment in which they live. In addition, he stated that nature does not release energy unnecessarily, that is, it is parsimonious.

Aristotle, a biologist two thousand years ahead of his time: Some biological observations made by Aristotle took centuries to be confirmed by naturalists, especially those referring to the habits of aquatic animals. Aristotle pointed out that the male of the catfish guarded the eggs laid by the female until the fry were born. For a long time, Aristotle’s assertions, fruit of his observations, were considered to be fables.

 

The origin and evolution of Biology

Biology can be defined in a seemingly simple but precise way as the science that studies life. The historical discussion revolves around what life is.

victorian_biologicalThe etymology of the word Biology is formed by the combination of the Greek terms: “bios” which means life and “logia” which means science.

The first samples of biology go back to the study of living beings and their vital manifestations from ancient times to our time. In this sense, the first classifications of living beings were made according to practical criteria considering usefulness and risk. It was not until the work of Linné (Carlos Linneo) saw the light, in the seventeenth century (Species Plantarum), when a “nature” classification was found.

Although the concept of Biology as a science was born in the 19th century, it studies all aspects or characteristics of living beings such as their chemical composition, reproduction, growth, metabolism, cellular organization and movement.

During the 18th and 19th centuries, biological sciences, such as botany and zoology, became scientific disciplines. It was during these centuries that Lavoisier and other physical scientists began to unite the animate and inanimate worlds through physics and chemistry. Explorer-naturalists, such as Alexander von Humboldt, expanded the fields of science by investigating the interaction between organisms and their environment, initiating biogeography, ethology, and ecology. Later, the cell theory provided a new appearance on the foundations of life.

 

The history of biology is divided into three major stages:

Ancient: theories and discoveries made from prehistory to the Middle Ages. In this sedentary stage of life, man began to observe phenomena of nature such as changes in seasons, tides, rainfall, all this attributed to the action of different gods; this way of explaining natural phenomena through religion and mythology lasted until the 6th century BC. Period in which several Greek philosophers called naturalists appeared, among them were Tales of Mileto, Anaximander, Pythagoras, Jenofanes of Colophon and Parmenides of Elea. Then the first documents of biology appeared, many of them attributed to Hippocrates and he is remembered for the Oath. Aristotle was considered the Father of Zoology; and Galen, last doctor of antiquity, as father of Anatomy.

Modern: With the Renaissance, this era of Biology began that lasted until just before the second decade of the 20th century. Here great biological changes were defined and some apparatuses and tools were invented that made research more optimal. Among the most important advances made in this stage is the invention of the microscope, with which biological structures that were not possible to see at first sight began to be observed.

Modern biology is based on several unifying themes, namely:

  • The Cell Theory.
  • The Theory of Evolution by Natural Selection of Darwin and Wallace.
  • Mendel’s Laws.
  • The Chromosomal Theory of Inheritance.
  • Crick’s Central Dogma on the flow of information.

This stage was also characterized by the use of an experimental work method and the attempt to relate cellular structures to their function. New fields of Biology emerged such as Microbiology and Genetics.

Within this period, some famous researchers stand out in the establishment of the importance of the cell as the fundamental anatomical unit of all living organisms. Among them are:

  • Robert Hooke: the first scientist to use the word “cell”.
  • Robert Brown: Established in 1831 that all cell types have a nucleus.
  • Matthias Schleiden and Theodor Schwann: In 1838, both biologists established that the cell was the fundamental anatomical and structural unit of all living beings. These would be two of the postulates of the Cell Theory.
  • Rudolf Virchow: Proposed the third postulate of the Cell Theory by ensuring in 1858 that the cell is the unit of origin.

Other important researchers of this time were Charles Darwin (theory of evolution); Louis Pasteur (founder of microbiology and creator of the rabies vaccine); Gregor Johann Mendel (Mendel’s laws) and Carlos Linneo (classification of organisms, system of nomenclature).

Molecular: This is the current moment, based on the basis of cellular constitution. Molecular life, which can be called biology of our time in a way, begins in 1920. The invention of the electron microscope, technological advances have made possible great achievements in the different fields of biology, highlighting in particular what has been achieved at the level of Genetic research.

At the beginning of the 20th century, the rediscovery of Mendel’s work led to the rapid development of genetics by Thomas Hunt Morgan and his students, the combination of population genetics and natural classification in modern evolutionary synthesis during 1930. New sciences developed rapidly, especially after James Watson (American biologist) and Francis Crick (British biologist) discovered the structure of DNA in 1953. At the end of the 20th century, new fields such as Genomics and Proteomics inverted this trend, with organic biologists using molecular techniques and investigating the interaction between genes and the environment.

 

Current

In the 21st century, biological sciences contributed as new and classic disciplines previously differentiated as physics in research fields such as biophysics. Advances were made in analytical chemistry and physical instrumentation, optical components, networks, satellites, and computing power for data collection, storage, visualization, and simulation. All of these technological advances allowed for the theoretical and experimental search for molecular biochemistry, biological systems, and ecosystem science. This made global entry possible for the improvement of measurements, complex simulations, analysis, observational content of data over the internet. New research fields in biological sciences emerged such as “bioinformatics” (application of computational technologies to the processing and observation of biological data). “Theoretical biology” (conceptual characterization of biological problems). “Computational genomics” (the use of computational analysis to interpret the biology of genome sequences). “Astrobiology” (combines biology and astronomy to study the origin, evolution, distribution, and future of life in the universe) and “Synthetic biology” (the synthesis of biomolecules, the belief that studies the chemical composition of living beings).

The current moment is that of biotechnology, genetic engineering, and genomics. Contributions from scientists, biochemists, physicists, and engineers are important within this stage, such as Max Perutz and John Kendrew, fundamental in the rapid development of structural biology; E. O. Wilson (biologist, father of biodiversity); Niels Kaj Jerne (immunologist, co-author with Frank Macfarlane Burnet of the clonal selection theory); Moto Kimura (author in 1968 of the neutralist theory of molecular evolution); Paul Berg (biochemist, obtained the first artificial DNA molecule, recombinant DNA, in 1972); Frederick Sanger (discoverer of the structure of insulin); Walter Gilbert (Nobel Prize in Chemistry for his studies on the structure and evolution of DNA sequences) and Carl Woese (creator of the new molecular taxonomy based on the comparison between species of the 16s and 18s mitochondrial RNA.

 

Some branches of Biology are:

  • Anatomy
  • Anthropology
  • Bacteriology
  • Biophysics
  • Marine biology
  • Biomedicine
  • Biochemistry
  • Biotechnology
  • Botany
  • Cytogenetics
  • Cytochemistry
  • Ecology
  • Entomology
  • Ethology
  • Evolution
  • Physiology
  • Genetics
  • Molecular genetics
  • Histology
  • Immunology
  • Microbiology
  • Parasitology
  • Paleontology
  • Taxonomy
  • Virology
  • Zoology
Continue Reading

Doctor

Willem Einthoven

Willem Einthoven Biography
https://www.instagram.com/p/BxvDpxTpjke/

Willem Einthoven Biography

Willem Einthoven (May 21, 1860 – September 28, 1927) Physiologist and physician. Nobel Prize in Medicine in 1924. He was born in Semarang, Indonesia. He is well known for his contributions to the development of the electrocardiograph and its clinical application. His father died when they lived in Java, so Willem moved to the University of Utrecht to study medicine.

After finishing his studies he obtained the position of professor at the University of Leiden to deal with the positions of physiology and histology. He took the opportunity to advance an important work in the field of research. He quickly showed himself as a reputable scientist, participated in numerous international scientific forums and the best thing is that by managing several languages ​​he could communicate his ideas faithfully without the need for translators.

For several years he experimented with the rope galvanometer and its utility for the registration of cardiac potentials, and the results obtained were published in an article in the year 1901. Five years later, he masterfully described the clinical applications of the electrocardiogram in Telecardiogramme (1906). After that, he published another article that laid the foundations for the development of this important tool in cardiology analysis. His investigative work was carried out simultaneously with his work as a professor.

Thanks to his work, the galvanometer was used to measure the differences in electrical potential during systolic and diastolic heart contractions and reproduce them graphically. This procedure is known as an electrocardiogram.

Later, he was interested in analyzing how healthy hearts worked and then defining a reference frame, through which attention was paid to the deviations caused by the disease. To sum up, he revolutionized the study, diagnosis, and treatment of cardiac pathologies. In his honor, the lunar crater Einthoven bears his name.

 

Continue Reading

Doctor

Lucy Wills

Lucy Wills Biography
https://www.instagram.com/p/BxR94Oknc_g/

Lucy Wills Biography

Lucy Wills (May 10, 1888 – 1964) hematologist and botany. She was born in Sutton Coldfield, United Kingdom. Her family enjoyed a good social and economic position. Therefore, she was able to study at Cheltenham Ladies ’College, an educational institute that offered high educational standards in teaching. Then, she studied Botany and Geology in 1911 but did not receive a Cambridge graduate degree until 1928, when Cambridge began granting degrees to women.

By that time, Wills had admirably managed to graduate as a doctor at the London Royal Free Hospital School of Medicine for Women. From the beginning, he knew that he would devote her knowledge to research and teaching in the Department of Pathological Chemistry of the same center in London. For the year 1928 Margaret Balfour contacted her. For several years she served as chief of pathology until her retirement in 1947.

After her retirement, she worked in South Africa and Fiji studying the effects of nutrition on health. During the last ten years of her life, she was a member of the local government for Chelsea. She started working on macrocytic anemia of pregnancy that primarily affects pregnant women in the tropics, with inadequate diets, this work was developed in several areas of India.

This woman is owed several contributions, such as discovering a nutritional factor in yeast that prevents and cures this disorder: the Wills factor or folate, the natural form of folic acid. In that sense, in the year 1930, she showed that anemia could be reversed with brewer’s yeast, which contains folate.

As part of a recognition of her work and the advancement of medicine, on May 10, 2019, the 131st anniversary of her birth, the Google search engine commemorated Wills with a Doodle available for North America, parts of South America and Europe, Israel, India, and New Zealand. Her knowledge changed the face of prenatal preventive care for women around the world.

 

WORKS

  • Studies on blood and urinary chemistry during pregnancy: blood sugar curves.
  • Studies in pernicious anemia of pregnancy (1930). This research has 4 parts.
  • Treatment of “pernicious anemia” of pregnancy and “tropical anemia” with special reference to yeast extract as a healing agent.
  • The nature of the hemopoietic factor in Marmite.
  • A new factor in the production and cure of certain macrocytic anemias.
  • Tropical macrocytic anemia: its relationship with pernicious anemia.
Continue Reading

Science

Claude Bernard

Claude Bernard Biography
https://www.instagram.com/p/Bwc-BVRn3ys/

Claude Bernard Biography

Claude Bernard (July 12, 1813 – February 10, 1878) physiologist. He was born in Saint-Julien, France. The top representative of the French physiology of the 19th century. His life was dedicated to studying the nervous regulation of salivary secretion, pancreatic digestion, and glycogenic liver function. He is admired for having discovered vasomotor innervation and creating the concept of internal secretion. His contributions to experimental pharmacology are also salvageable.

Bernard at nineteen entered as a clerk in a pharmacy in Vaise, a suburb of Lyon. He liked literature so he wrote a drama entitled Arthur de Bretagne, he went to Paris; but then he started studying medicine, leaving literature aside. At first, he had the guidance of the physiologist François Magendie, who was a trainer, and soon gave proof of his genius. In 1843 he could already demonstrate the glycogenic function of the liver. He was an assistant to Magendie and professor of physiology at Collège de France. In the year of 1853, he obtained the title of doctor of science with the thesis Investigations about a new function of the liver, considered as a producing organ of sugary matter.

The following year he was a professor of experimental medicine at the Collège de France. Years later, and thanks to the knowledge acquired, he wrote Introduction to the study of experimental medicine (1865) allowed him to be part of the French Academy; this year he was entrusted with the chair of general physiology of the Sorbonne Natural History Museum, and in 1869 he was appointed member of the Imperial Senate of Napoleon III. In 1870 his intellectual vitality was affected by a kidney disease contracted because of the cold and humidity of his laboratory.

This French defended the determinism linked to neo-vitalism. He also studied, in addition to hepatic glycogenesis, the sympathetic nervous system and poisons. Among his works are Leçon sur la physiologie expérimentale appliquée a la médecine (1856), Les propriétés des tissus vivants (1866) and Leçon Sur Les phenomènes de la vie (1878).

In broad strokes, his works advocated naturalistic principles and thus generated a great influence that he exerted on the naturalist movement, mainly in Zola. Bernard establishes the rules of medicine that is true science and method, must have a solid foundation. For hi medicine must be like physics and chemistry, a science that undergoes an experimental method. But experience is not proven simply by the facts, without being guided by a precise conviction; rather, it must be rigorous and complete experimentation. So, the philosophical and theological yoke is excluded, admitting a personal scientific authority.

Thus, Bernard says, the hypotheses will encourage discoveries and experimentation serves as a guide. Émile Zola developed in his thinking of naturalist novelist Bernard’s famous scientific premises; his essay The experimental novel represents the attempt to apply the principles of physiology to a conception of art. Unfortunately, he died on February 10, 1878. He is remembered for being one of the referents of experimental physiology of the nineteenth century, and, at the same time, one of the most illustrious thinkers of the time in Europe. The medicine had many advances in an anomaly that affects the sympathetic nerves of the face, it was called Claude Bernard-Horner syndrome.

Similarly, he contributed to the development of therapeutics, diabetes, indications of bleeding, detoxification by carbon monoxide through mechanical ventilation, the treatment of anemia with iron lactate, the decrease in body temperature through physical means, treatment of alcohol intoxication, morphine applications, the effects of carbon dioxide, intravenous administration of physiological serum, cardiopulmonary resuscitation techniques, among others.

Continue Reading

Celebrities

Entrepreneurs

Most Popular

Our partners will collect data and use cookies to serve you personalized ads and measure performance.    More information
Privacidad