How much sex a person has is the result of many factors… but are there any that seem more important? To find out, these researchers collected data from 254 women in their thirties, asking them about their personal and physical lives. It turns out that over 40% of the women sampled had sex at least twice a week, and that obese women were more likely to have sex at least three times a week. I guess they really don’t call it the “dirty thirties” for nothing!
“This cross-sectional study aimed to identify factors related to coital frequency (CF) among 254 women in their 30s using a semistructured interview to collect sociodemographic, anthropometric, reproductive, clinical, and relationship data. CF was characterized as (a) never, (b) rarely (≤1 times/month), (c) occasionally (≤1 times /week), (d) regularly (2-3 times/week), or (e) frequently (>3 times/week). Read More
At first glance, this may seem like a completely moronic question. I mean, wet stuff feels wet because… well, it’s wet. Duh! But when you stop to think more deeply about it it, it quickly becomes a very profound question. That’s because, unlike heat or touch, we don’t have any sensors in our skin capable of directly detecting wetness. Therefore, scientists believe that we rely on other senses, like temperature or touch, to indirectly sense when something is wet. To test this idea, scientists wet subjects’ forearms while interfering with their senses of touch and temperature. Without being able to see their arms, the participants rated how wet they thought they were. In the end, interfering with their senses of touch and temperature did reduce the participants’ ability to sense wetness, providing support for the hypothesis. Taking a bath will never feel quite the same again…
Why wet feels wet? A neurophysiological model of human cutaneous wetness sensitivity.
“Although the ability to sense skin wetness and humidity is critical for behavioral and autonomic adaptations, humans are not provided with specific skin receptors for sensing wetness. Read More
“Tasmanian devil joeys, like other marsupials, are born at a very early stage of development, prior to the development of their adaptive immune system, yet survive in a pathogen-laden pouch and burrow. Antimicrobial peptides, called cathelicidins, which provide innate immune protection during early life, are expressed in the pouch lining, skin and milk of devil dams. These peptides are active against pathogens identified in the pouch microbiome. Of the six characterised cathelicidins, Saha-CATH5 and 6 have broad-spectrum antibacterial activity and are capable of killing problematic human pathogens including methicillin-resistant S. aureus and vancomycin-resistant E. faecalis, while Saha-CATH3 is active against fungi. Read More
Ever want to make a whirpool-like vortex out of your semen? Well, according to this published study, it’s not too difficult:
Step 1: Concentrate the sperm in your semen.
Step 2: Put it into a annular-shaped container (a ring formed by two concentric circles).
Step 3: Stand back to admire the beauty that is your very own semen vortex.
Apparently, concentrating the sperm induces them to align and swim in the same direction around the ring, creating a vortex… a vortex of semen!
Note: anyone attempting to make their own sperm vortex at home should definitely read the materials and methods of the full text for tips.
“New experimental evidence of self-motion of a confined active suspension is presented. Depositing fresh semen sample in an annular shaped microfluidic chip leads to a spontaneous vortex state of the fluid at sufficiently large sperm concentration. Read More
If you are looking for a (fun) way to pass a painful kidney stone, look no further! This study focused on whether having regular sex helps pass kidney stones lodged in the lower end of the ureter (the tube that connects the kidney to the bladder). Over 80% of patients who were asked to have sex 3-4 times a week passed their stones, compared to about 35% of control patients. So it looks like urine luck!
“OBJECTIVE: To investigate the effect of sexual intercourse on spontaneous passage of distal ureteral stones.
MATERIAL AND METHODS: The patients were randomly divided into 3 groups with random number table envelope method. Patients in group 1 were asked to have sexual intercourse at least 3-4 times a week. Patients in group 2 were administered tamsulosin 0.4 mg/d. Patients in group 3 received standard medical therapy alone and acted as the controls. The expulsion rate was controlled after 2 and 4 weeks. Differences in the expulsion rate between groups were compared with the chi-square test for 3 × 2 tables. P
RESULTS: The mean stone size was 4.7 ± 0.8 mm in group 1, 5 ± 1 mm group 2, and 4.9 ± 0.8 mm group 3 (P = .4). Two weeks later, 26 of 31 patients (83.9%) in the sexual intercourse group, and 10 of 21 patients (47.6%) in tamsulosin group passed their stones, whereas 8 of 23 patients (34.8%) in the control group passed their stones (P = .001). The mean stone expulsion time was 10 ± 5.8 days in group 1, 16.6 ± 8.5 days in group 2, and 18 ± 5.5 days in group 3 (P = .0001).
CONCLUSION: Our results have indicated that patients who have distal ureteral stones ≤6 mm and a sexual partner may be advised to have sexual intercourse 3-4 times a week to increase the probability of spontaneous passage of the stones.”
NCBI ROFL: The odors of the human vagina.
NCBI ROFL: What’s happening in your brain while you pee?
NCBI ROFL: Semen collection in rhinoceroses by electroejaculation with a uniquely designed probe.
When you have an itch, you should scratch it. But what if you have a disease like eczema, where scratching can make everything worse? Enter these scientists, who set out to determine whether your brain can be tricked into thinking an itch has been scratched when it hasn’t. First, they “experimentally induced” itching by injecting histamine (eek!) into a subject’s right arm. Then, they scratched the subject’s left arm while holding up a mirror, which made it appear that the right arm was being scratched. And it worked! “Scratching the non-itching limb attenuated perceived itch intensity significantly and selectively in the mirror condition, i.e., when the non-itching forearm was visually perceived as the itching limb.” So the next time you scratch an itchy mosquito bite until it bleeds, stop — and try a mirror instead!
The goal of this study was to test whether central mechanisms of scratching-induced itch attenuation can be activated by scratching the limb contralateral to the itching limb when the participant is made to visually perceive the non-itching limb as the itching limb by means of mirror images.
Healthy participants were asked to assess the intensity of an experimentally induced itch at their right forearm while they observed externally guided scratch movements either at their right (itching) or left (non-itching) forearm which were either mirrored or not mirrored. In the first experiment, a mirror placed between the participant’s forearms was used to create the visual illusion that the participant’s itching (right) forearm was being scratched while in fact the non-itching (left) forearm was scratched. To control visibility of the left (non-mirrored) forearm, a second experiment was performed in which unflipped and flipped real-time video displays of the participant’s forearms were used to create experimental conditions in which the participant visually perceived scratching either on one forearm only, on both forearms, or no scratching at all. Read More
The previously innocent–if slightly narcissistic–“selfie” has now been adapted for a morbid purpose. Here, a group of Brazilian researchers report on the successful identification of a burn victim by analyzing teeth from selfies. Although not as informative as dental records, the ubiquity of selfies will likely prove to be an invaluable resource for forensic scientists of the future. Say cheese!
“As with other methods of identification, in forensic odontology, antemortem data are compared with postmortem findings. In the absence of dental documentation, photographs of the smile play an important role in this comparison. As yet, there are no reports of the use of the selfie photograph for identification purposes. Owing to advancements in technology, electronic devices, and social networks, this type of photograph has become increasingly common. This paper describes a case in which selfie photographs were used to identify a carbonized body, by using the smile line and image superimposition. Read More
If you’re watching your waistline, you probably already know that taking the stairs can help you burn calories. But not everyone climbs stairs the same way. For example, there are those pesky over-achievers who take the stairs two at a time–they must be burning more calories for all that extra effort, right? Well, not so fast. These scientists set out to test whether taking the stairs two at a time really does burn more calories. And while we won’t spoil the punchline entirely for you, let’s just say that total calorie burn isn’t only related to the intensity of the exercise.
“Stairway climbing provides a ubiquitous and inconspicuous method of burning calories. While typically two strategies are employed for climbing stairs, climbing one stair step per stride or two steps per stride, research to date has not clarified if there are any differences in energy expenditure between them. Read More
Here’s a new result from the field of Chasmology that may or may not make you yawn: according to this study, yawning duration is correlated with brain size in mammals. How did these researchers uncover this correlation? Why, by watching YouTube videos of animals yawning, of course! The authors suggest that animals with bigger or more complex brains require longer yawns to get the full effects of the yawn, which (while still somewhat mysterious) may be related to brain cooling. And if you made it through all this talk of yawning without yawning yourself, then you’re definitely stronger than I am!
“Research indicates that the motor action pattern of yawning functions to promote cortical arousal and state change through enhanced intracranial circulation and brain cooling. Because the magnitude of this response likely corresponds to the degree of neurophysiological change, we hypothesized that interspecies variation in yawn duration would correlate with underlying neurological differences. Using openly accessible data, we show that both the mean and variance in yawn duration are robust predictors of mammalian brain weight and cortical neuron number (ρ-values > 0.9). Read More
When it comes to premier veterinary care, the first image that often springs to mind is surgery performed on a beloved dog or cat. But dogs and cats are not the only pets to receive this level of care: fish can undergo surgery, too! Such procedures require specialized treatments, including waterborne anesthesia. And if you are wondering what sorts of procedures are most common, wonder no more! This paper outlines the surgeries most often performed on fish, many of which are familiar to all pet owners, including removal of tumors, retrieval of swallowed items, and fertility treatments. There are also procedures that more fish-specific, such as the insertion of radio transmitters for tracking wild fish. We just hope they don’t try to slap on a band-aid after all that!
“Fish surgical procedures are commonplace in aquaria, zoos, laboratory facilities, and pet clinical practice. Read More