Atividades Práticas Supervisionadas – Tradução de Texto Científico

Nome: Letícia Silva Belasco       R.A: C574ji9

Medicine

Breastfeeding, also known as nursing, is the feeding of babies and young children with milk from a woman's breast Health professionals recommend that breastfeeding begin within the first hour of a baby's life and continue as often and as much as the baby wants. During the first few weeks of life babies may nurse roughly every two to three hours and the duration of a feeding is usually ten to fifteen minutes on each breast. Older children feed less often. Mothers may pump milk so that it can be used later when breastfeeding is not possible. Breastfeeding has a number of benefits to both mother and baby, which infant formula lacks.

Deaths of an estimated 820,000 children under the age of five could be prevented globally every year with increased breastfeeding.  Breastfeeding decreases the risk of respiratory tract infections and diarrhea, both in developing and developed countries. Other benefits include lower risks of asthma, food allergies, type 1 diabetes, and leukemia. Breastfeeding may also improve cognitive development and decrease the risk of obesity in adulthood. Mothers may feel pressure to breastfeed, but in the developed world children generally grow up normally when bottle fed.

Benefits for the mother include less blood loss following delivery, better uterus shrinkage, and less postpartum depression. Breastfeeding delays the return of menstruation and fertility, a phenomenon known as lactational amenorrhea. Long term benefits for the mother include decreased risk of breast cancer, cardiovascular disease, and rheumatoid arthritis. Breastfeeding is less expensive than infant formula.

Health organizations, including the World Health Organization (WHO), recommend breastfeeding exclusively for six months. This means that no other foods or drinks other than possibly vitamin D are typically given. After the introduction of foods at six months of age, recommendations include continued breastfeeding until one to two years of age or more. Globally about 38% of infants are only breastfed during their first six months of life. In the United States, about 75% of women begin breastfeeding and about 13% only breastfeed until the age of six months. Medical conditions that do not allow breastfeeding are rare. Mothers who take certain recreational drugs and medications should not breastfeed Smoking, limited amounts of alcohol, or coffee are not reasons to avoid breastfeeding.

Lactation

Changes early in pregnancy prepare the breast for lactation. Before pregnancy the breast is largely composed of adipose (fat) tissue but under the influence of the hormones estrogen, progesterone, prolactin, and other hormones, the breasts prepare for production of milk for the baby. There is an increase in blood flow to the breasts. Pigmentation of the nipples and areola also increases. Size increases as well, but breast size is not related to the amount of milk that the mother will be able to produce after the baby is born. By the second trimester of pregnancy colostrum, a thick yellowish fluid, begins to be produced in the alveoli and continues to be produced for the first few days until the milk "comes in", around 30 to 40 hours after delivery. Oxytocin contracts the smooth muscle of the uterus during birth and following delivery, called the postpartum period, while breastfeeding. Oxytocin also contracts the smooth muscle layer of band-like cells surrounding the alveoli to squeeze the newly produced milk into the duct system. Oxytocin is necessary for the milk ejection reflex, or let-down, in response to suckling, to occur.

Breast milk

Not all of breast milk's properties are understood, but its nutrient content is relatively consistent. Breast milk is made from nutrients in the mother's bloodstream and bodily stores. It has an optimal balance of fat, sugar, water, and protein that is needed for a baby's growth and development.  Breastfeeding triggers biochemical reactions which allows for the enzymes, hormones, growth factors and immunologic substances to effectively defend against infectious diseases for the infant. The breast milk also has long-chain polyunsaturated fatty acids which help with normal retinal  and neural development.

The composition of breast milk changes depending on how long the baby nurses at each session, as well as on the child's age. The first type, produced during the first days after childbirth, is called colostrum. Colostrum is easy to digest although it is more concentrated than mature milk. It has a laxative effect that helps the infant to pass early stools, aiding in the excretion of excess bilirubin, which helps to prevent jaundice. It also helps to seal the infants gastrointestional tract from foreign substances, which may sensitize the baby to foods that the mother has eaten. Although the baby has received some antibodies through the placenta, colostrum contains a substance which is new to the newborn, secretory immunoglobulin A (IgA). IgA works to attack germs in the mucous membranes of the throat, lungs, and intestines, which are most likely to come under attack from germs.

Breasts begin producing mature milk around the third or fourth day after birth. Early in a nursing session, the breasts produce foremilk, a thinner milk containing many proteins and vitamins. If the baby keeps nursing, then hindmilk is produced. Hindmilk has a creamier color and texture because it contains more fat.

Atividades Práticas Supervisionadas – Texto Jornalístico

Nome: Anderson Germano                           R.A. T6798E-6

Nome: Diego Figueiredo Aguilar                   R.A. C74EFH-8

Nome: Fábio Augusto Farias Monção           R.A. C1338G-5

NEWS

Britain needs to go on a diet, says top health official.

By Nick Triggle

Health correspondent

6 March 2018

The portion sizes of some of Britain's most popular foods are to be cut, with health officials telling the public it is time "to get on a diet".

Public  Health  England  is  targeting  pizzas, ready meals processed meat and takeaways, in a new obesity drive.

The government agency has also urged the food industry to start using healthier ingredients and encourage the public to opt for lower calorie foods.

It is all part of a drive to cut calorie consumption by 20% by 2024.

The target will apply to 13 different food groups, responsible for a fifth of the calorie intake of children.

It comes on top of: the sugar reduction programme, launched last year, which is targeting nine different food groups; the sugar drinks Ievy, which comes into force next month.

Combined, these three measures mean health officials are taking direct action to influence the consumption of foods responsible for half of children's calories.  Public 'tricked' into buying unhealthy food; Third of adults ‘underestimate calories’; Sugar targets set for cakes and chocolate.

But PHE chief executive Duncan Selbie said the steps were as much about influencing the diets of adults.

”Britain needs to go on a diet. Children and adults routinely eat too many calories, and it’s why so many are overweight or obese."

The popular foods being targeted

Food manufacturers, supermarkets, takeaways and fast-food outlets have been told to reduce the calories in the following foods: savoury biscuits and crackers; speciality breads such as ciabatta with olives; cooking sauces and dressings; crisps and savoury snacks; egg products; potato products; meat products, such as pies, pastries, sausages and burgers; pasta, rice and noodles; ready meals and takeaways; dips; pizza; food-to-go, such as sandwiches; soups.

If action is not taken, PHE said, it would be prepared to ask the government to legislate. It would be strictly monitoring progress by looking at which products people were buying and would be prepared to "name and shame" individual companies not pulling their weight.

Targets for breakfast, lunch and dinner

The agency is also launching a campaign encouraging adults to consume 400 calories at breakfast and 600 each at lunch and dinner. It is being seen as a rough guide for consumers to follow when they buy meals away from home. A quarter of food is now bought from cafes, restaurants, takeaways or as food-to-go from shops.

Sophie said: "Before that app I didn't care how many calories I ate a day"

PHE said major groups such as McDonald's, Subway and Greggs would be promoting foods that kept people within these guidelines.

Currently adults consume between 200 and 300 calories more than they should each day.

PHE chief nutritionist Dr Alison Tedstone said the 400-600-600 tip would make it easier for "people to make healthier choices" by being able to judge what they should be eating in each sitting. "To get traction on this, the big-selling things need to change," she said. "A few healthy options on the end of a menu won't help solve the nation's obesity problem - we need the regular, everyday products to change."

How many calories should we eat?

It is recommended that women should eat no more than 2,000 calories a day, while men should limit their intake to 2,500.For children, it varies depending on age. A four-year-old should consume no more than 1,300, while for males aged 17 and 18 it is about 3,000, but overweight and obese children are consuming up to 500 calories more than that.

The move has been backed by experts. Prof Russell Viner, of the Royal College of Paediatrics and Child Health, said it was a "bold and necessary" move. He said over the past 40 years there had been a "creep" in portion sizes, with pizzas and hamburgers "simply much bigger than they were in our parents' time".

"The availability of fast food at pocket money prices and the advertising of unhealthy food and drinks to children add to the problem," he added.

Atividades Práticas Supervisionadas – Texto Científico de Astronomia.

Nome: Patrícia Gomes                        T2811E1

Nome: Thadeu Theodoro de Sillos     C625DB1

Black Holes

Don't let the name fool you: a black hole is anything but empty space. Rather, it is a great amount of matter packed into a very small area - think of a star ten times more massive than the Sun squeezed into a sphere approximately the diameter of New York City. The result is a gravitational field so strong that nothing, not even light, can escape. In recent years, NASA instruments have painted a new picture of these strange objects that are, to many, the most fascinating objects in space.

Although the term was not coined until 1967 by Princeton physicist John Wheeler, the idea of an object in space so massive and dense that light could not escape it has been around for centuries. Most famously, black holes were predicted by Einstein's theory of general relativity, which showed that when a massive star dies, it leaves behind a small, dense remnant core. If the core's mass is more than about three times the mass of the Sun, the equations showed, the force of gravity overwhelms all other forces and produces a black hole.

Scientists can't directly observe black holes with telescopes that detect x-rays, light, or other forms of electromagnetic radiation. We can, however, infer the presence of black holes and study them by detecting their effect on other matter nearby. If a black hole passes through a cloud of interstellar matter, for example, it will draw matter inward in a process known as accretion. A similar process can occur if a normal star passes close to a black hole. In this case, the black hole can tear the star apart as it pulls it toward itself. As the attracted matter accelerates and heats up, it emits x-rays that radiate into space. Recent discoveries offer some tantalizing evidence that black holes have a dramatic influence on the neighborhoods around them - emitting powerful gamma ray bursts, devouring nearby stars, and spurring the growth of new stars in some areas while stalling it in others.

One Star's End is a Black Hole's Beginning

Most black holes form from the remnants of a large star that dies in a supernova explosion. (Smaller stars become dense neutron stars, which are not massive enough to trap light.) If the total mass of the star is large enough (about three times the mass of the Sun), it can be proven theoretically that no force can keep the star from collapsing under the influence of gravity. However, as the star collapses, a strange thing occurs. As the surface of the star nears an imaginary surface called the "event horizon," time on the star slows relative to the time kept by observers far away. When the surface reaches the event horizon, time stands still, and the star can collapse no more - it is a frozen collapsing object.

Even bigger black holes can result from stellar collisions. Soon after its launch in December 2004, NASA's Swift telescope observed the powerful, fleeting flashes of light known as gamma ray bursts. Chandra and NASA's Hubble Space Telescope later collected data from the event's "afterglow," and together the observations led astronomers to conclude that the powerful explosions can result when a black hole and a neutron star collide, producing another black hole.

Babies and Giants

Although the basic formation process is understood, one perennial mystery in the science of black holes is that they appear to exist on two radically different size scales. On the one end, there are the countless black holes that are the remnants of massive stars. Peppered throughout the Universe, these "stellar mass" black holes are generally 10 to 24 times as massive as the Sun. Astronomers spot them when another star draws near enough for some of the matter surrounding it to be snared by the black hole's gravity, churning out x-rays in the process. Most stellar black holes, however, lead isolated lives and are impossible to detect. Judging from the number of stars large enough to produce such black holes, however, scientists estimate that there are as many as ten million to a billion such black holes in the Milky Way alone.

On the other end of the size spectrum are the giants known as "supermassive" black holes, which are millions, if not billions, of times as massive as the Sun. Astronomers believe that supermassive black holes lie at the center of virtually all large galaxies, even our own Milky Way. Astronomers can detect them by watching for their effects on nearby stars and gas.

Historically, astronomers have long believed that no mid-sized black holes exist.  However, recent evidence from Chandra, XMM-Newton and Hubble strengthens the case that mid-size black holes do exist. One possible mechanism for the formation of supermassive black holes involves a chain reaction of collisions of stars in compact star clusters that results in the buildup of extremely massive stars, which then collapse to form intermediate-mass black holes. The star clusters then sink to the center of the galaxy, where the intermediate-mass black holes merge to form a supermassive black hole.