Amidst the battle for supremacy, our army of immune cells relentlessly wages war against various pathogens, especially superbug bacteria. Despite the pool of ample winnings, our body still experiences defeat from time to time. We succumb to diseases as the war reels its favor towards the tenacious pathogens. Of course, we cannot allow our immune defense to be utterly defeated. Otherwise, we’d be dead. As bacteria advance by taking over much space and nutrients inside our body, we get external help through antimicrobial chemicals that scientists continue to contrive. Unfortunately, antibiotic resistance has surfaced and turned certain strains of bacteria into a superbug – one that has become resistant to the effects of antibiotics.
Chemical warfare prior to the rise of a superbug
Antimicrobial chemicals, particularly antibiotics, came into existence as chemicals that were strategically designed and produced with the intent of killing pesky bacteria. In 1928, penicillin was discovered, which led to its use as the first natural antibiotic capable of undermining a spectrum of bacteria, if not by killing, by inhibiting their growth. Its role as a wonder drug against various bacteria caused Alexander Fleming to receive a duly recognition by winning a Nobel prize award for its discovery. Soon, more antibacterial agents came up to our defense. Antibiotics, such as penicillin and cephalosporin, destroy bacterial cell wall whereas polymyxins target bacterial cell membrane. Rifamycin, quinolones, sulfonamides, and the likes interfere with the enzymes essential to bacteria. Once again, we gained an upper hand.
Bacteria resisting: the rise of a superbug
While we thought we finally came up with a powerful weapon, the bacteria conjured up an amazing strategy to work in their favour — antibiotic resistance. Some of them started to morph. They evolved and mutated into new strains referred to as superbug. They became capable of resisting the drugs’ antimicrobial effects. One of their strategies is to produce β-lactamases that destroy the structure of β-lactam antibiotics (e.g. penicillin and cephalosporin). The bacteria that evolved into superbug organisms did not just live; they thrived. They multiplied and passed on to the next generation the features that could withstand a number of antibiotics.
DNA uptake by superbug bacteria
Apart from the vertical gene transfer of genes, antibiotic resistance could also be transferred through horizontal gene transfer. It is a mechanism whereby genes are taken up or transposed from one species to another, and one of the possible explanations for the rise of superbug bacteria. DNA uptake by a bacterial cell was captured for the first time in a video by a team of scientists from Indiana University. In the video1, it shows how a bacterial cell takes up DNA fragments from dead bacterial cells through its pilus. Like a harpoon, the pilus was used by the bacterium, Vibrio cholera, to catch and reel a stray DNA fragment, and then bring it inside the bacterial cell via the same pore on its cell wall. It, then, incorporates the DNA into its own genome. Accordingly, this is probably one of the mechanisms for a bacterium to turn into a superbug.
First video evidence of DNA uptake by Vibrio cholera.
(Video credit: Ankur Dalia, Indiana University, uploaded on YouTube by Group IU Biology News)
A researcher from the team, Courtney Ellison, recounted, “The size of the hole in the outer membrane is almost the exact width of a DNA helix bent in half… If there weren’t a pilus to guide it, the chance the DNA would hit the pore at just the right angle to pass into the cell is basically zero.” It appears that the pilus takes a crucial role in horizontal gene transfer. If left to chance the DNA fragment would not easily get inside the cell since the pore was too small for it to fit. Through horizontal gene transfer, those that were once sensitive to the antibiotic could later become superbug bacteria as well. As Ankur Dalia, another researcher from the same team, pointed out, “Horizontal gene transfer is an important way that antibiotic resistance moves between bacterial species….” The video that the research team captured for the first time could explain how antibiotic resistance can be acquired from one superbug bacterial species to another.
The battle is far from over. The antibiotic resistance already raised global concerns as it has rendered certain antibiotics ineffective. Pathogenic superbug bacteria have successfully armed themselves with genes that could neutralize antibiotic effects. Fortunately, scientists do not waver in determining the strategies that superbug bacteria exploit. The recent discovery of the way by which bacteria employ to make them antibiotic-resistant superbug strains could lead to better therapeutic strikes that could counter them, hopefully, with ample success.
— written by Maria Victoria Gonzaga
1 Indiana University. (2018). IU scientists watch bacteria ‘harpoon’ DNA to speed their evolution. Retrieved from https://news.iu.edu/stories/2018/06/iub/releases/11-scientists-watch-bacteria-harpoon-dna-to-speed-their-evolution.html
The ability to focus one’s attention on a specific point of interest for a given time is referred to as selective attention. Imagine a scenario wherein you can pay attention to everything. That would lead to information overload. Selective attention enables an individual to react to certain stimuli from among those occurring simultaneously. This ability is crucial particularly when you need to focus on a task you need to finish before the time is up. You tend to put much of your attention to your target and then ignore potential distractions.
Neurobiology of selective attention
Selective attention is one of the neural functions of the brain. The neurons relay the information from one neuron to the next by releasing neurotransmitters, such as acetylcholine, at the synapse. The neurons responsible for our capacity to focus are found in the lateral prefrontal cortex.1 They are also responsible for suppressing potential distractions in the background. For more neurobiological aspect and potential therapeutic targets, read Selective Attention – neurobiology and potential therapeutics.
Selective attention and inattentional blindness
While we can choose which of the things to focus on and which ones to ignore, there are also instances wherein we tend to overlook things beyond our will. One of the possible consequences of selective attention is inattentional blindness, which is the phenomenon of not being able to perceive things although they are just right in front of our eyes. Because we are focused on one thing, there is a tendency that other things escape us. For instance, you might not notice the tiniest details on your essay (e.g. misspelled words) or missed key information from a reference book.
Inattentional blindness can be perfectly demonstrated through Daniel Simons and Christopher Chabris’ invisible gorilla test. The test is a video of two basketball teams in which the viewer has to count how many times the ball is tossed around to the team members. The viewer would likely be so busy counting that the person in a gorilla suit walking back and forth on the background would easily go unnoticed. Because of selective attention, we are inclined to filter things out. We might even think that we saw everything but, in fact, we only see what we want to see. Thus, letting other salient details to slip out while on selective attention is not unusual.
Brief diversions improve selective attention
Imposing short and momentary breaks helps to rest mentally from sustained stimulations, and thereby, possibly keep up excellent selective attention.
One could easily surmise that selective attention and distractions should never go together when one wants to complete a highly demanding task. However, this seems to be the opposite based on what Atsunori Ariga and Alejandro Lleras from University of Illinois at Urbana-Champaign found in their study.2 Repetitive tasks that required prolonged selective attention could wind up to diminished quality in performance. The researchers presumed that diminishing attention per se was not the culprit to a poor performance but the constant stimulation happening in the brain. Lleras explained: “Constant stimulation is registered by our brains as unimportant, to the point that the brain erases it from our awareness.” What their study implicates is to impose short and momentary breaks to rest mentally from sustained stimulations. Brief breaks, as they proposed, will help to stay focused while doing long, arduous tasks, such as studying before an exam.2
Perhaps, we can all agree that there are times when selective attention can be a cinch and then there are also times when it is simply impossible. We can get easily distracted. There are just so many factors that prevent us from focusing on a daunting task. An emotional turmoil, for instance, is one such distraction that can be difficult to overcome. Nevertheless, these studies open up to possibilities how diversions and distractions can be put to use to uphold selective attention to tasks that need to be done over prolonged periods of time.
— written by Maria Victoria Gonzaga
1 McGill University. (2015, January 7). Having a hard time focusing? Research identifies complex of neurons crucial to controlling attention. ScienceDaily. Retrieved from www.sciencedaily.com/releases/2015/01/150107081701.htm
2 University of Illinois at Urbana-Champaign. (2011, February 8). Brief diversions vastly improve focus, researchers find. ScienceDaily. Retrieved June 5, 2018, from www.sciencedaily.com/releases/2011/02/110208131529.htm
Common bottlenose dolphins are the largest species of the beaked dolphins that inhabits in temperate and tropical oceans worldwide. These species are large that mostly found in groups and known to mixed with other species like whales and cetaceans. Common bottlenose dolphin diet mainly squid, eel, shrimp and wide variety of fishes by swallowing a whole than chewing it. Dolphins usually search prey using echolocation in a form of sonar. And uses sounds for communication like squeaks emitted from blowhole, whistles from nasal sacs and body language. The coastal of United States Pacific is known to have around 450 individuals while the offshore population about 3,495 individuals. In Canadian west coast no common bottlenose dolphin has been documented. However, on July 29, 2017 a sighting of this species mixed with cetaceans and killer whales has been observed.
Common bottlenose dolphins observed in Canadian waters
For the first time common bottlenose dolphins have been observed on July 29, 2017 in Canadian water. Each individual shows particular characteristics like short to moderate beak. A curved mouth line that dips downward resembling like a smile and tall falcate dorsal fin at the central back. Moreover, the body colors were usually light grey to black on the back and side while light to white color around the belly.
The sighting of the large group of common bottlenose dolphins is the first confirmed occurrence in Canadian Pacific waters. The location of sighting is approximately 1000 km northwest coast of America which signifies the first northernmost record of the species. About 200 dolphins were seen in the group in an unusual large aggregation. On the other hand it was also observed that this dolphins traveling closely with false killer whales, a typically offshore species.
The discovery of common bottlenose dolphins and false killer whales signifies the warming trends in North Pacific waters. Both of the species typically inhabit warm temperate waters in lower latitudes. But this sighting indicates that British Columbia, Canada oceanic conditions gives suitable habitat for them. It is also recorded that the show-up happened after a prolonged warming period.
Source: Prepared by Joan Tura from Springer Nature BMC Marine Biodiversity
Vol. 11: 3, 20 April 2018
Waterbirds are very important indicators in the ecosystem particularly wetlands. Due to climate change and human activities such as pollution, over-hunting and habitat loss about 23% globally are declining. Some have been listed as threatened species by the International Union for Conservation of Nature (IUCN) for about 19% worldwide. In view of this severe condition, waterbirds diversity has been rapidly decreasing and its conservation status received attention. In China there are 53.6 million hectares of wetlands making it the first among Asia and fourth in the world. There were different wetland types in China including swamps, rivers, lakes, coastal wetlands and estuaries. Conservation of waterbirds in China has been implemented establishing nature reserves, designating key habitat and captive breeding to increase population.
Population Trends of Waterbirds in China
According to Wetlands International there were 871 waterbird species in 32 families and 8 orders in the world. In China, 260 waterbird species has been identified that belongs to 21 families. 84 species exhibited a declining trend, 35 species remained stable while 16 species showed increasing trends. Threatened species includes Critically Endangered, Endangered, Vulnerable, Near Threatened, Least Concern and Data Deficient. Moreover, the migratory and residents waterbirds suffered serious threats and a total of 38 species listed as threatened species. Also there were 6 species listed as Critically Endangered, 16 species Vulnerable, 16 species Endangered and 27 species as Near Threatened.
Threats to waterbirds include both direct and indirect human activities such as illegal hunting, disturbances, pollution and habitat loss. However, habitat loss is the most common threat because of large scale reclamation in both coastal and inland wetlands. According to the national surveys a decreased of 3.4 million hectares of wetlands wherein coastal losses more than inland wetlands. In recent years, continuous development and industrialization affects the natural habitats of waterbirds. In which foraging time have been reduced, vigilance behavior increased and recurrently being flushed away. As a consequence human disturbances forced the birds to abandon habitats and nest due to breeding failure.
Therefore, waterbirds in China might be in more serious situation than we thought that is why conservation must be implemented. Like restoration of degraded wetlands, public awareness, cracking down on illegal hunting and enforcement of Wildlife Protection Law. Additionally, restoration of highly threatened species through artificial intervention is needed. As well as promoting cooperation between international and regional information on conservation.
Source: Prepared by Joan Tura from Springer Nature BMC Avian Research
Published: 28 April 2018
Respiratory failure is an outcome from inadequate gas exchange wherein arterial oxygen and carbon dioxide not at normal levels. A drop of oxygen is called hypoxemia while the rise in arterial carbon dioxide is hypercapnia. Respiratory failure includes abnormal blood gases, increased of breathing and increased respiratory rate. In obstetric patients a complicated conditions occurs resulting to various complications and several physiological changes. That is why risk of complication in pregnancy with respiratory failure considered challenge for positive maternal and neonatal outcomes.
Causes in Maternal Respiratory failure
The main causes of respiratory failure were postpartum hemorrhage, peripartum period, preeclampsia and pneumonia during pregnancy. In which the oxygen reserve impairment during pregnancy causes fast desaturation leading to fetal hypoxia. Many of the patients showed improvement after delivery in partial pressure of arterial oxygen. But some exhibited high incidence of neonatal respiratory distress syndrome. Neonatal complications were commonly caused by sepsis and meconium aspiration syndrome as well as impairment in neurological development.
Acute respiratory distress syndrome is classified as mild to severe injuries from aspiration, trauma and multiple transfusions. It is also a condition of newborn having dyspnea with cyanosis that is often related to surfactant deficiency. However, preterm infant retinas showed incomplete retinal vascularization. On the other hand obstetric patients showed 74% having maternal respiratory failure complications while 25.4% to non-obstetric patients.
Indeed, early delivery might improve maternal oxygenation and reduce mortality rate. However maternal respiratory failure may not always improve after the delivery wherein deleterious sepsis and lung injury persist after delivery. Additionally a detailed examination is needed to follow up the neonates in the future. Using the risk categories whether normal, questionable and abnormal, if the mental developmental index is <70 then the neonates are suspected to have mental retardation.
Source: Prepared by Joan Tura from Journal of the Formosan Medical Association
Volume 117, Issue 5, May 2018, Pages 413-420
A very warm welcome to noted human performance expert and Mayo Clinic physician, Dr. Michael Joyner
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