Hallan reptil más antiguo que los dinosaurios

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HISTORIA 23/01/15

Un reptil carnívoro de tres metros de longitud, dientes como cuchillos y placas óseas que vivió antes de la era de los dinosaurios ha sido descubierto por el Prof. Sterling Nesbitt y sus colegas del Instituto Politécnico y Universidad Estatal de Virginia, en Estados Unidos. 

La nueva especie ha sido nombrada Nundasuchus songeaensis, una mezcla de la palabra swahili nunda o “predador” y del griego suchus o “cocodrilo”. Songeaensis deriva de Songea, el pueblo donde fueron encontrados los restos fosilizados. 

El corpulento reptil era pesado, con las extremidades bajo su cuerpo como un dinosaurio o un pájaro, pero con placas óseas en la espalda como un cocodrilo. El esqueleto fue descubierto en 2007 en Tanzania, sin embargo, pasaron varios años antes de que el Prof. Nesbitt y su equipo pudieran semblar las miles de piezas encontradas.

El descubrimiento ayudará a los paleontólogos a entender mejor el árbol evolutivo reptiliano, pues existe una gran brecha de conocimiento en torno a la época en que vivió el ancestro común de las aves y los cocodrilos. Los investigadores continúan estudiando el espécimen para entender las implicaciones de su hallazgo. 

El Prof. Nesbitt, de 32 años, ha estado involucrado en el nombramiento de 17 especies reptilianas y dinosaurios diferentes durante los últimos 10 años, siete de los cuales descubrió él mismo. 

La investigación ha sido publicado en Journal of Vertebrate Paleontology.

Crédito de la imagen: UNED/ Wikimedia Commons

Fuente: http://www.muyinteresante.com.mx/historia/15/01/23/identifican-nuevo-reptil-carnivoro-prehistorico/

Capturan extraño tiburón anguila

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NATURALEZA 23/01/15

Un tiburón anguila, especie extremadamente rara, por desgracia fue capturado por un barco pesquero cerca de Lakes Entrance, en la región de Victoria Gippsland, Australia. La buena noticia es que ofrece una mejor oportunidad de estudiar a la fascinante criatura, siendo la primera vez que se observa en dicha región.

Científicos de la Agencia científica nacional de Australia, CISRO, han confirmado que el espécimen es un tiburón anguila (Chlamydoselachus anguineus), a menudo llamado un "fósil viviente". Exhibe varias características primitivas y su género existe desde tiempos prehistóricos, remontándose al menos 80 millones de años. 

El espécimen capturado mide tan sólo dos metros de longitud, aunque se sabe que el tiburón anguila puede llegar a alcanzar los cinco metros. Habitan los océanos Atlántico y Pacífico, incluyendo las costas de Marruecos, Escocia y Japón.

La especie posee seis pares de hendiduras branquiales, con apariencia de flecos, y aunque se asemeja una anguila, tiene las aletas y cola de un tiburón. Su boca contiene  300 dientes, tan filosos como agujas, acomodados en más de 26 hileras, lo cuales utiliza para tragar a sus presas enteras.

La pesca involuntaria del tiburón anguila no es algo común, pues normalmente se encuentran a profundidades de 1,200 metros. El espécimen que quedó atrapado en las redes pesqueras fue hallado a sólo 700 metros de profundidad. Al parecer, sólo tuvo mala suerte.

En el siguiente video podrás ver a un tiburón anguila filmado en Japón en 2007

Fuente: http://www.muyinteresante.com.mx/naturaleza/15/01/23/capturan-tiburon-anguila/

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Original: http://revista.asomigua.org/category/blog/
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Original: http://revista.asomigua.org/2014/11/
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Triclosan: The dirty side of the soap bar

20. January 2015

On account of its antibacterial effects triclosan is added to many wash lotions and detergents. Recent studies indicate that the substance could also promote liver cancer. Above all, hospital staff are at risk.

Triclosan has long since been no blank slate. For several years the synthetic antimicrobial substance has been regularly producing headlines. It was in 1972 that triclosan came onto the market as an additive in disinfectant hand wash lotions for hospital staff, since 1998 evidence has been mounting about its harmful effects. Nevertheless, the material has over the last twenty years increasingly found its way into many objects intended for daily use. Triclosan is present in cosmetics, toothpaste, household cleaners, detergents, sports clothing and kitchen utensils.
There are despite that already numerous indications that triclosan could be cause for serious concern for both human health and the environment: in face cleansers triclosan is thought to provide a path for the potentially pathogenic bacteria Staphylococcus aureus to be able to increasingly settle in the human nose. In cases involving surgery or a weak immune system this can increase the infection rate. In laboratory experiments triclosan enhanced the growth of breast cancer cells. Animal experiments have also shown that Triclosan can affect the function of muscles and the hormone system. This synthetic agent was detected in the blood, the urine and in the breast milk of many volunteers.

Larger liver, more cells happily dividing

A recent study involving experiments on mice provided evidence that, with long-term contact, triclosan damages the liver and could possibly favour the emergence of liver cancer. In order to examine how triclosan affects the liver, the researchers fed young mice for eight months with triclosan-containing feed, control animals received the same diet without triclosan. Next, the researchers examined the livers of the animals. The result: the livers of mice fed with triclosan were unusually large. At an intracellular level it was observed that genes that stimulate division of liver cells were active. This process could result in liver fibrosis, the researchers write. The liver fibrosis can in turn increase the risk of liver cancer. This is because, if during the course of liver fibrosis the tissue of the liver is increasingly converted to collagen, the liver function is affected, the researchers write. In order to test their assumption they gave both the triclosan-mice and control animals a carcinogenic medication. In the triclosan-mice more and larger tumours had grown than in the control animals.

Results are not simply transferable

Translating this in human terms, the corresponding dose of triclosan used in this experiment would be 0.05 mg per kg body weight. This corresponds to about one gram of toothpaste containing 0.3 percent triclosan. “Of this, the majority soon disappears down the drain”, write the researchers. The results of animal experiments do not lend themselves to being transferred 1:1 to humans. “Since triclosan is however almost ubiquitous, damage to the liver in humans cannot be excluded as a possibility”. Long-term studies will bring more clarity here, stipulate the scientists.

Long since in the food chain

In effluent water triclosan is able to be degraded to methyltriclosan,which has a much longer half-life in the environment. Methyltriclosan also has a very high accumulation potential in living organisms via the food chain, it says on the website of the German Federal Institute for Risk Assessment (BfR). In the USA triclosan occupies seventh place in the list of substances that are most often reported in America’s rivers. Triclosan is proven to be present In the body fluids of wildlife. With an annual worldwide production volume of around 1,500 tonnes this is hardly surprising.

Triclosan penetrates as far as the foetus

The good news: triclosan apparently does not accumulate in the body. “If the body is no longer exposed to the substance, triclosan is fairly quickly flushed out. Since the substance however occurs almost universally, the exposure to it is ubiquitous”, explains Dr. Rolf Halden from Arizona State University. Under his leadership a team of scientists examined the triclosan load in pregnant women and their foetuses. “We were able to detect triclosan in the urine of all pregnant women who participated in our study. Approximately half of the cord blood samples were positive as well. This means that triclosan most likely also manages to get into the foetus”, according to one scientist involved in the study, Dr. Benny Pycke.

Doctors, nurses and nursing carers at particular risk

In particular it’s hospital staff who regularly clean their hands with antibacterial wash lotions that end up accumulating a great deal of triclosan in the body. This was shown by a study of staff from two hospitals who washed their hands either using cleaning agent with a triclosan component of 0.3 per cent, or simply soap and water. The employees who regularly used triclosan-containing wash lotion had significantly more triclosan in the urine than the soap-using group.
All the same: triclosan has since 2010 in Europe not been permitted for use in food and materials that come into direct contact with food. In 2012, a German-Slovak research team placed the substance at number six among the most problematic substances in Europe. Germany’s BfR has been warning for several years about the use of the substance in detergents and textiles and the US Food and Drug Administration is currently again reviewing the risk-benefit ratio of the substance. Whether this leads to stricter guidelines remains to be seen.

Fuente:  http://news.doccheck.com/en/newsletter/1523/10282/?utm_source=DC-Newsletter&utm_medium=E-Mail&utm_campaign=Newsletter-EN-DocCheck+News-2015-01-16&user=1479eb13b686c9c528b8911e6b9e012b&n=1523&d=28&chk=69f1318c3fb0c15c84bc248761959c89

Jajaja

lobeglitazona

Lobeglitazone and pioglitazone as add-ons to metformin for patients with type 2 diabetes: a 24-week, multi-centre, randomized, double-blind, parallel-group, active-controlled, phase III clinical trial with a 28-week extension 
Diabetes, Obesity and Metabolism, 01/12/2015  Clinical Article

Jin SM, et al. – The authors aimed to compare the efficacy and safety of lobeglitazone and pioglitazone as add–ons to metformin in patients with type 2 diabetes. Lobeglitazone was not inferior to pioglitazone as an add–on to metformin in terms of the efficacy and safety.

Methods

• Patients who were inadequately controlled by metformin were randomized and treated once daily with either lobeglitazone (0.5 mg, n = 128) or pioglitazone (15 mg, n=125) for 24 weeks, with a 28-week extension of lobeglitazone treatment in patients who consented.

Results

• The primary endpoint was the change in HbA1c level between baseline and week 24.
• At week 24, the mean change from baseline HbA1c was -0.74% for the lobeglitazone group and -0.74% for the pioglitazone group, with a mean difference of 0.01% [95% confidence interval (CI) of difference, -0.16 to 0.18].