1. During the most recent ice age, monsoons in northern africa may have brought enough rain to create three major river systems that ran north across the sahara to the mediterranean, creating a path for human migration out of africa. "This paper uses a novel palaeohydrological and hydraulic modelling approach to test the hypothesis that under wetter climates c.100,000 years ago major river systems ran north across the Sahara to the Mediterranean, creating viable migration routes. We confirm that three of these now buried palaeo river systems could have been active at the key time of human migration across the Sahara. Unexpectedly, it is the most western of these three rivers, the Irharhar river, that represents the most likely route for human migration. The Irharhar river flows directly south to north, uniquely linking the mountain areas experiencing monsoon climates at these times to temperate Mediterranean environments where food and resources would have been abundant." (PLoS One c/o Nature news)
2. In a big RCT (n=657) electronic cigarettes were associated with a 7.3% quitting rate at 6 mos compared to nicotine patches (5.8%) and placebo in the form of e-cigarettes with no nicotine (4.1%). (Lancet, c/o Hopkins podmed podcast) It'd be interesting to know what the baseline quitting rate is without any intervention.
3.Whale earwax-- like an ice core, but made of earwax, and for a whale. Whale earwax apparently accumulates over time, and can be extracted in one piece after its death and analyzed much like an ice core or a tree core. Concentrations of various substances can be measured and correlated with time-- from pollutants like mercury and pesticides to endogenous hormones like cortisol. A group from Baylor reported the findings on an earwax sample from a 12 year old blue whale, finding increased concentration of toxins in its first year of life (possibly from maternal transfer in milk), and increased cortisol levels corresponding with sexual maturity. (Nature news)
4. Surgical tool analyses smoke from electrocautery to provide real-time data on the content of tissues-- including the presence of cancer cells. The tool is an electrocautery knife (iKnife) connected to a mass spec that analyses lipid ratios in the vaporized tissue; it's able to identify the nature (neoplastic vs benign) and even the origin of the tissue if it was metastatic. Trials of the tool in live resections yielded promising findings-- "Tissue identification via intraoperative REIMS matched the postoperative histological diagnosis in 100% (all 81) of the cases studied. The mass spectra reflected lipidomic profiles that varied between distinct histological tumor types and also between primary and metastatic tumors." (Science trans med) This is pretty impressive, given that the tool does in 1-3 seconds what a surgical pathologist takes 30+ minutes to do. (c/o Science news blog)
5. Low risk ankle rule: currently about 95% of kids who present to an ER with an ankle injury will receive an x-ray, while only 12% of them actually have a fracture that requires treatment. This paper in the Lancet (prospective trial, n=607) found a 100% sensitivity, 100% NPV of the low-risk ankle rule in ruling out high-risk ankle injuries, and argue that in implementing this rule could lead to over 60% reduction in x-rays, vs only 12% reduction in the ottowa rules. However, another study in the Annals of Emergency Med (prospective, n=272) found only an 87% sensitivity of the low-risk ankle rule. Perhaps variation in examiner technique or patient population explains the discrepancy.
The low-risk ankle rule: if tenderness/swelling is limited to distal fibula or the 3 ligaments around it (distal to tibial anterior joint line)
High-risk injuries: fracture of the foot, distal tibia, and fibula proximal to the distal physis; tibiofibular syndesmosis injury; and ankle dislocations.
Low-risk ankle injuries: lateral ankle sprains; nondisplaced Salter-Harris types I and II fractures of the distal fibula; and avulsion fractures of the distal fibula or lateral talus. (c/o contemporary pediatrics)
6. Methylprednisone injections were able to reduce symptom severity in patients with carpel tunnel syndrome at 10 weeks but not at 1-year, according to a new double-blind randomized placebo-controlled trial published in the Annals of Internal Med. At 1-year, surgery rates were 73%, 81%, and 92% for patients who had received 80mg steroid, 40mg steroid, and placebo injections respectively. (c/o Hopkins PodMed)
7. Useful meta-analysis published in JAMA found a few simple clinical exam findings to be predictive of rotator cuff injury-- a great video narrates the findings of the paper and illustrates (literally) the relevant exams and findings. (c/o Hopkins PodMed)
Findings:
--1. Presence/absence of pain is NOT useful in identifying those with rotator cuff tears
--2. Infraspinatus atrophy made rotator cuff disease more likely
--3. Painful arc test was the only finding with a likelihood ratio>2 for positive rotator cuff injury; negative painful arc test had the lowest negative LR (0.36). To do this test, you have the patient start fully adducted, and abduct their arm 180 degrees. Pain between 60 and 120 degrees is considered a positive finding. Pain at 45 degrees suggests significant impingement (of rotator cuff tendons and subacromial bursa), pain at 60-70 degrees suggests moderate impingement.
Other pain tests were not found to be useful in detecting RC disease, notably: Hawkins test (pt flexes elbow and shoulder 90 degrees, examiner internally rotates arm) and Neer test (examiner fully flexes arm that is slightly abducted, internally rotated, and pronated)
--4. Positive external lag test (pt cannot maintain flexed elbow externally rotated to the side) or internal lag test (pt cannot maintain arm internally rotated behind back) were diagnostic of a full-thickness RC tear. Negative internal lag test excluded RC tear.
--5. Positive dropped arm sign (pt cannot resist downward pressure on an arm abducted 90 degrees, arm drops) increases likelihood for any RC injury.
--6. Positive external rotation resistance test (pain or weakness when trying to externally rotate arm against resistance) was accurate in diagnosing disease.
In sum: do the painful arc test, the internal and external lag test, dropped arm test, and external rotation resistance tests.
8. Catfact: Tibetan monks are better at protecting snow leopards than government agents hired to protect snow leopards. (Economist)
9. A team in japan is using GC-Mass spec to authenticate poop coffee (Economist) (J Ag Food Chem)
10. An immense shield volcano, of a size comparable to the largest known volcano in the solar system (olympus mons), discovered off the coast of Japan. (Nature c/o NPR). From the abstract: We show that the Tamu Massif is a single, immense volcano, constructed from massive lava flows that emanated from the volcano centre to form a broad, shield-like shape. The volcano has anomalously low slopes, probably due to the high effusion rates of the erupting lavas."