Little African fish join forces to get food
Lake Tanganyika, the second largest in the world in volume and the second deepest, borders four countries, but it is at its southern end, in Zambia, where the species Neolamprologus obscurus lives, small freshwater fish with rays that They feed mostly on prawns and other invertebrates that they find in the depths.
At night, the crustaceans move towards the water column but sink back into the bottom of the lake at dawn to hide in wells and pits, including the shelters that the fish have excavated under the rocks. In these hollows, the prawns become trapped and become the prey of N. obscurus.
“The function of these excavated cavities is very similar to that of social spider webs, which live in groups and share the prey caught between the different members of the group,” stresses Hirokazu Tanaka, lead author of the study published in Behavioral Ecology and Sociobiology and researcher at the University of Bern in Switzerland and at the University of Osaka City in Japan.
The work has allowed determining how the digging of these holes is done, which serve as a trap to capture the shrimps. According to the scientists, excavation is always done in a group, as well as its subsequent maintenance. Breeding females do not leave the safe shelter and have family support or helpers to protect the young and extract the sand that enters the holes.
To confirm this behavior, Tanaka’s team checked whether the size of the cavities at the bottom of the lake was related to the abundance of food available in the area and whether the presence of the helpers influenced the size. After spending several hours diving, the scientists created artificial cavities and analyzed the stomach contents of the fish.
In another experiment, the biologists removed the aides who were assisting the females. After a week, so much sand had entered the cavities that their size had been reduced, especially in the case of holes with larger helpers.
The results confirmed that the size of the refuge of the fish in the rocks influences the amount of shrimp that hide and become trapped in it. With a larger number of helpers, the space that can be created is larger and therefore more crustaceans can be captured.
“The assistants enlarge and maintain the excavated cavities, and in doing so, contribute to an increase in the abundance of food within the territory of the breeding females,” says Tanaka, for whom the group life of this species increases the number of prey, as well as the corporal conditions and the reproductive success of all the individuals.
Endometriosis, the disease of the modern woman
Displacement of the endometrium, which affects 6 million Brazilians, can cause sterility and intense cramps
The cramps and pains in the body that suffer most women during the menstrual period may not simply be natural reflexes of the reproductive cycle. On this National Endometriosis Fight Day (8), the alert is for women to watch for signs of their body that may indicate the problem of endometriosis.
Known as the ” modern woman’s disease “, endometriosis is characterized by the presence of the endometrium, tissue that lines the uterus and fixes the embryo, outside the organ itself. The illness is usually related to the woman of the last decade due to overwork in the society of contemporary society, which can cause the famous lack of time to take care of one’s own body and to perceive signs of illness.
According to data from the Brazilian Association of Endometriosis (ABEND), the disease affects around six million Brazilians, which is equivalent to approximately 15% of the female population in the reproductive phase. Of these, 30% have a chance of becoming sterile.
Endometriosis does not have fixed and unanimous causes, however, the most accepted by the medical community is that of retrograde menstruation.
“In most women, the menstrual flow does not just go out through the vagina but also through the tubes into the body, such as in the belly, the ovary and the bladder,” explains Dr. Ivan Penna, a human reproduction specialist and professor of medicine of the Federal Fluminense University (UFF).
From this internal flow, the tissue is fixed in places where it should not, and there is a change in its structure, after healing. This way, women menstruate every month in these regions of the body, which increases and repeats the disorder, causing endometriosis.
Endometriosis causes various maladies, such as bowel obstruction and decreased bladder capacity, which may culminate in sterility. However, what plagues women most with the disease is the pain it causes.
“The cramps and pains of women with endometriosis during menstruation become so intense that they become incapacitating, an impediment to well-being,” says Penna. “Feeling pains in the menstrual period is not normal, although many see this way, and should be observed if they are progressive, increasing in frequency or intensity over time.”
The best procedure for the disease depends on the symptoms presented. In some cases, temporary clinical, contraceptive-based treatment is sufficient, for example.
However, when more active intervention is required, surgery is recommended, which consists of removal of the endometrium from sites other than the uterus.
Still, as the menstrual cycle continues, a woman can return to developing endometriosis even after surgery. “The only cure for endometriosis is menopause,” says Penna.
For women who know they have endometriosis and wish to become pregnant, it is advisable to freeze the eggs for later in vitro fertilization. As the treatment is surgical, the ovary can be lost, which would prevent a natural fertilization.
They look for ways to control maize diseases through genetics
Within the Center for Bioinvestigations of UNNOBA (CeBio) (Argentina), Dr. Inés Catalano directs the project funded by the Commission of Scientific Investigations of the Province of Buenos Aires (CIC), in which two species are studied of “leafhoppers”: Delphacodes kuscheli, vector of the agent that causes the “Evil of Río Cuarto”; and Dalbulus maidis, which causes corn stunting. “While the evil of Río Cuarto affects the core zone, what is known as ‘achaparramiento’ occurs more towards the north of the country. With a different scope, the entire maize area was affected in one or another campaign by these diseases, “said Catalano. The model they use takes some axes of the advances achieved by research developed at the University for the study of the kissing bugs.
The research team is focused on studying different aspects of the vector that transmits the causal pathogen of these diseases. What they seek is to determine which genes affect the development or survival of these insects to try to find a control method that preserves the crop and does not affect its performance. “We have the transcriptome sequenced in all stages and we have an infected colony that we are maintaining to be able to work in the search for immunity genes,” he said. With both species try the same thing: discover genes that can be used to devise ways in which the plant itself can exercise some control over the plague. The Deputy Director of CeBio remarked that the relevance of the research is given by the impact that these insects and the diseases they transmit have on the cultivation of corn.
In fact, the “leafhoppers” have a buccal system similar to that of the kissing bugs. “The leafhoppers and the kissers are of the same order of insects, have the same buccal apparatus and have a similar behavior. The only difference is that the kissers feed on human blood and the leafhoppers of ‘the blood of the plant. According to Catalano, all the knowledge generated in this field will be novel because “there are no studies on leafhoppers that are so specific. The transcriptome and the genome are not studied, so any gene we discover will be an advance. ”
Currently, the management of these diseases is carried out through the use of insecticides. The purpose of this research is to have the knowledge to develop a plant that contains genes that may have the ability to inhibit others of the insect to make your life does not persist. “Our highest aspiration would be to achieve an insecticide method, provide knowledge for the development of a plant that carries with it certain characteristics that affect the development and survival of these pests,” concluded the project director.
The development of this project involves the participation of professionals from different disciplines. With anchoring in genetics, each of them deploys a task within the framework of this research.
Victorio Palacio, from the Bioinformatics, is devoted to the analysis of the transcriptome of the species studied.
Lucia Dalaison, who is doing her final thesis of the Degree in Genetics, managed to develop the entire life cycle of the leafhoppers artificially. It is also devoted to the study of the normal embryonic development of insects.
Hugo González is an agronomist, has a doctoral fellowship from CONICET and is responsible for the maintenance of infected insects in colonies. You will also have the task of comparing the transcriptome of healthy and infected.
Lucila Pérez has a CIN scholarship and is doing the final work of the degree in Genetics. It was inserted in the project to study neuropeptides in “chinches”, an insect that affects the soybean crop.
Elías Gazza has a degree in Genetics, a doctoral fellowship from CONICET and is putting genome editing techniques to the test.
WHO publishes new guidelines on childbirth with focus on individuality
The UN agency has presented a list of 56 recommendations based on scientific evidence and gathered in the new guidelines on childbirth.
The right to decide how to control pain during childbirth and to reject unnecessary medical interventions are two of the recommendations that are part of the new guidelines developed by the World Health Organization (WHO) on how to manage care for pregnant women.
The United Nations agency on Thursday unveiled a list of 56 recommendations based on scientific evidence and brought together in the new guidelines on childbirth. The goal is to highlight the importance of a mother being at the center of decisions and to discard unnecessary medical interventions.
“The guidelines propose a holistic approach to childbirth where the mother has a pre-eminence,” said Olufemi Oladapo, a specialist in maternal health research at the WHO Department of Reproductive Health.
It is estimated that annually 140 million births worldwide occur, the vast majority without complications. However, over the past two decades the use of medical interventions that were previously only made when there was a risk or some complication, such as the administration of oxytocin to help in dilation or a cesarean section, has been greatly increased.
According to WHO, on many occasions, these interventions are not only unnecessary but also cause the mother to have a negative experience in childbirth. It is estimated that a large number of healthy women, with a normal process, received some type of intervention, although the report does not give concrete data.
Because of this, the agency drew up rules that emphasize the importance of an unmedicalized delivery, which includes the possibility for the mother to decide how to manage her own pain, which involves deciding whether or not to use epidural anesthesia and, if want, at what time.
In addition, the new guidelines recognize that each delivery is a delivery and that rules implemented over the past 70 years should not be maintained. An example of this is the dilation of the neck of the uterus. Until now, it was believed to be “normal” for him to expand by one centimeter per hour. The new guidelines state that these limits are ” unrealistic ” and ” inadequate ” to determine if a child is progressing poorly or is simply slower than average.
“These rules were established in the 1950s and we have enormous scientific evidence that shows that in many cases this does not happen because each delivery is unique. In fact, the speed with which the uterus dilates does not have any importance in the chances of survival of the baby, as long as there is progress, “said Oladapo.
He stated that no other category of speed has been established for dilatation because they do not want to “restrict” delivery again to a rule since what should change in the mentality of doctors and midwives is that each case is different.
Another generalized intervention is the episiotomy, the surgical incision in the vulva made in certain deliveries to facilitate the exit of the fetus.
“It is almost barbaric and almost routine, although its advantages are a complete myth,” exclaimed Oladapo, explaining that the method should only be used in extreme cases, due to the multiple negative consequences for the mother in the future.
Another intervention used excessively is a cesarean section. According to the organization, the method is applied in many countries of average investment routinely, for the convenience of doctors, and because in many cases, the experts charge much more for a surgical delivery than for a natural one.
“The guidelines are intended for doctors and remind them of the risks in the short and medium term of cesareans, but also mothers, so that they know they are entitled to a birth as natural as possible and with their control.”