Insights into dike nucleation and eruption dynamics from high-resolution seismic imaging of magmatic system at the East Pacific Rise.

Models of magmatic systems suggest that the architecture of crustal magma bodies plays an important role in where volcanic eruptions occur, but detailed field observations are needed to evaluate them. We present ultrahigh-resolution reflection images of magma bodies beneath a region of multiple eruptions along the East Pacific Rise derived from three-dimensional seismic surveying. The observations reveal magma bodies with elongate ridges and troughs vertically aligned with seafloor eruptive fissures that we interpret as remnant dike root zones where repeat dikes nucleate. We document a triangular feeder zone to the axially centered magma body from the off-axis source for a newly forming seamount of the Lamont chain and infer bottom-up eruption triggering due to recharge from this deeper source. The findings indicate that magma bodies are sculpted by both processes of magma recharge from below and magma extraction to the surface, leaving a morphological imprint that contributes to localization of dike nucleation and eruption sites at the East Pacific Rise.

The Alternatives to Traditional Materials for Subsoil Stabilization and Embankments.

Major infrastructure projects require significant amount of natural materials, often followed by the soft soil stabilization using hydraulic binders. This paper presents the results of a laboratory study of alternative waste materials (fly ash and slag) that can be used for earthworks. Results of high plasticity clay stabilization using fly ash from Serbian power plants are presented in the first part. In the second part of the paper, engineering properties of ash and ash-slag mixtures are discussed with the emphasis on the application in road subgrade and embankment construction. Physical and mechanical properties were determined via following laboratory tests: Specific gravity, grain size distribution, the moisture-density relationship (Proctor compaction test), unconfined compressive strength (UCS), oedometer and swell tests, direct shear and the California bearing ratio (CBR). The results indicate the positive effects of the clay stabilization using fly ash, in terms of increasing strength and stiffness and reducing expansivity. Fly ashes and ash-slag mixtures have also comparable mechanical properties with sands, which in combination with multiple other benefits (lower energy consumption and CO2 emission, saving of natural materials and smaller waste landfill areas), make them suitable fill materials for embankments, especially considering the necessity for sustainable development.

CONTINUOUS NON-INVASIVE ARTERIAL PRESSURE DEVICE AS AN ADJUNCT TO RECOGNIZE FLUCTUATING BLOOD PRESSURES DURING ELECTIVE CESAREAN SECTION UNDER SUBARACHNOID BLOCKADE (SAB).

BACKGROUND: Measuring non-invasive blood pressure (NIBP) in less than one minute intervals (STAT NIBP measurements) is not always feasible. Therefore, large number of undetectable hypotension episodes can only be recognized with continuous beat to beat monitoring of blood pressure, for example, by continuous non-invasive arterial pressure monitor (CNAP). OBJECTIVE: The purpose of the current study was to investigate whether CNAP correlates well with conventional intermittent oscillometric NIBP during elective cesarean sections under subarachnoid blockade (SAB) and whether CNAP based patient management results in improved immediate maternal vasopressor requirements and improved immediate fetal/neonatal outcomes compared with NIBP based patient management. MATERIALS AND METHODS: The CNAP finger cuff together with the CNAP arm cuff were placed on the same arm which also had the peripheral intravenous access.. On the contralateral arm the conventional NIBP arm cuff was placed. Study Group: The patients were managed by the anesthesia provider based on the CNAP monitor readings. Control Group: The patients were managed by the anesthesia provider based on the NIBP monitor readings. Results: The CNAP-based treatment (study) group had a statistically significant lower use of oxytocin and lower estimated blood loss than the NIBP-based treatment (control) group. The differences in incidences of vasopressors use and peri-operative nausea vomiting between study group and control group did not reach statistical significance. CNAP readings were more likely to be in systolic hypotensive phases (80mmHg) as compared to NIBP readings. CONCLUSION: Continuous non-invasive arterial pressure (CNAP) device may ONLY act as an adjunct to recognize fluctuating blood pressures during elective cesarean section under subarachnoid blockade (SAB).

Post-partum anaphylaxis: universal but successful management protocol should not deter appreciation of underlying etio-pathogenesis plethora.

Post-partum Anaphylaxis in mothers is extremely rare and has been reported secondary to initiation of the breast-feeding. However, we hereby report the occurrence of post-partum anaphylaxis in a post-partum patient in the absence of the initiated breast-feeding.

Multiple mechanisms of rhabdom shedding in the lateral eye of Limulus polyphemus.

Rhabdom shedding in horseshoe crab lateral eye photoreceptors was studied with anti-opsin and anti-arrestin immunocytochemistry. Two, possibly three, distinct shedding mechanisms were revealed in animals maintained in natural lighting. Transient rhabdom shedding, triggered by dawn, is a brief, synchronous event that removes up to 10% of the rhabdom membrane. Whorls of rhabdomeral membrane break into vesicles and form compact multivesicular bodies. These debris particles are immunoreactive for opsin and are of a relatively uniform size, averaging approximately 2 microm(2) in area. Transient shedding requires that input from circadian efferent fibers to the retina precedes the light trigger, and cutting the optic nerve blocks efferent input and transient shedding. Light-driven rhabdom shedding is a progressive process. Rhabdomeral membrane is removed by coated vesicles that accumulate into loosely packed multivesicular bodies. These debris particles label with antibodies directed against opsin, arrestin, and adaptin, and they have a large distribution of sizes, averaging almost 6 microm(2) in area and ranging up to 25 microm(2) or more. The amount of rhabdomeral membrane removed by light-driven shedding has seasonal variation and depends on latitude. Light-driven shedding does not require circadian efferent input. A possible third shedding mechanism, light-independent shedding, is observed when transient shedding is blocked either by 48 hours of darkness or by cutting the optic nerve. Small particles, averaging 1.8 microm(2) in area, exhibiting opsin but not arrestin immunoreactivity can then be found in the cytoplasm surrounding the rhabdom. The nature of light-independent shedding is not yet clear.