Molecular and cellular mechanisms underlying the evolution of form and function in the amniote jaw.

The amniote jaw complex is a remarkable amalgamation of derivatives from distinct embryonic cell lineages. During development, the cells in these lineages experience concerted movements, migrations, and signaling interactions that take them from their initial origins to their final destinations and imbue their derivatives with aspects of form including their axial orientation, anatomical identity, size, and shape. Perturbations along the way can produce defects and disease, but also generate the variation necessary for jaw evolution and adaptation. We focus on molecular and cellular mechanisms that regulate form in the amniote jaw complex, and that enable structural and functional integration. Special emphasis is placed on the role of cranial neural crest mesenchyme (NCM) during the species-specific patterning of bone, cartilage, tendon, muscle, and other jaw tissues. We also address the effects of biomechanical forces during jaw development and discuss ways in which certain molecular and cellular responses add adaptive and evolutionary plasticity to jaw morphology. Overall, we highlight how variation in molecular and cellular programs can promote the phenomenal diversity and functional morphology achieved during amniote jaw evolution or lead to the range of jaw defects and disease that affect the human condition

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Role of arterial hypertension in comorbidity of chronic headaches

INTRODUCTION: The literature concerning the association between headache and arterial hypertension is very scarce, mostly prior to the actual IHS classification and based on very diverse methods, being therefore difficult to interpret. OBJECTIVES: To analyse the association between arterial hypertension and two types of chronic headache and to determine, if and how arterial hypertension may affect the outcome of prophylactic therapy for chronic headaches. PATIENTS AND METHODS: Sixty four files of our headache outpatient clinic, chosen randomly among patients suffering from migraine or tensional type headache (TTH), were analysed retrospectively. Patients were considered hypertensive, if blood pressure was higher than normal several times without an acute crisis present. Resistance to treatment was defined as lack of benefit concerning number and/or intensity of crisis. RESULTS: Age varied between 18 and 80 years, the mean age being 42,9 (SD 13,86) years. Eighty six percent were females. Twenty nine patients suffered from TTH and 35 from migraine. Prevalence of hypertension was 35,9% among all patients, 28,5% among migraine patients, 44,8% among patients with TTH. The prevalence of resistance to treatment was 39,8%, 34,3% and 41,3%, respectively. Of the patients resistant to treatment 60% were hypertensive and 62,5% of the hypertensive patients showed resistance to therapy. CONCLUSIONS: Arterial hypertension was more prevalent in the study sample than would be expected in an equivalent sample of the general population. Hypertension was significantly more prevalent among patients resistant to therapy, as was resistance to treatment among hypertensive patients. We therefore conclude that there is a relevant comorbidity between chronic headache and hypertension and that arterial hypertension complicates the control of chronic headaches

INTERMOLECULAR FORCES IN SOLUTION AND LATTICE ENERGIES OF IONIC-CRYSTALS - CALORIMETRIC EXPERIMENTS FOR THE PHYSICAL-CHEMISTRY UNDERGRADUATE LABORATORY

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