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International audience; This study aims to reconstruct the hydro-climatic variations over the last 1000 years in Haiti using mineralogical and geochemical composition of well dated lacustrine sediment core retrieved from Lake Azuei. The results show changes in sedimentological processes linked to environmental and climatic variations. The general pattern suggests a wetter Medieval Climate Anomaly (MCA), drier Little Ice Age (LIA), high climate variability during the MCA-LIA transition and more anthropogenic impacts that dominate natural climate during the Current Warm Period (CWP). The MCA period (~1000–1100 CE) thus appears marked by increase sedimentation rate supported by higher terrigenous input linked to erosive events particularly increases in precipitation. During the LIA, particularly from ~1450 to 1600 CE, there is a great variation toward a decrease of terrigenous input, which is related to a decrease on sedimentation rate and increase Mg-calcite precipitation, suggesting less precipitation and high evaporation respectively during dry climate conditions. The MCA-LIA transition (~1200–1400 CE) is characterized by variations between terrigenous input, Mg-calcite formation and organic matter deposition, which indicate succession of dry and humid conditions. The CWP (1800–2000 CE) shows a progressive increase on sedimentation rate and decrease of gray level, which indicate more organic matter sedimentation as consequence of anthropogenic activities in the surrounding basin of the lake. High-resolution gray level analysis, which reflects principally variations in terrigenous input, carbonate mineral formation and organic matter deposition, shows that the AMO, NAO, PDO and ENSO are the principal modes affecting the hydro-climatic changes in Haiti during the last millennium. In addition, temporal correlation of other Caribbean paleoclimate records with our geochemical and mineralogical data, suggests that trends observed in Lake Azuei were controlled by regional climate, likely associated with shifts in the position of the ITCZ.

Supplementary Materials and Methods. Supplementary Figure S1: Cell viability in various concentrations of DNA-damaging agents and novel ATR pathway inhibitors. Supplementary Figure S2: Effects of novel and established ATR pathway inhibitors on Chk1 phosphorylation induced by hydroxyurea or cisplatin as assessed by flow cytometry.

Objective Acupuncture is a complex multicomponent treatment that has shown promise in the treatment of fibromyalgia (FM). However, clinical trials have shown mixed results, possibly due to heterogeneous methodology and lack of understanding of the underlying mechanism of action. The present study was undertaken to understand the specific contribution of somatosensory afference to improvements in clinical pain, and the specific brain circuits involved. Methods Seventy-six patients with FM were randomized to receive either electroacupuncture (EA), with somatosensory afference, or mock laser acupuncture (ML), with no somatosensory afference, twice a week over 8 treatments. Patients with FM in each treatment group were assessed for pain severity levels, measured using Brief Pain Inventory (BPI) scores, and for levels of functional brain network connectivity, assessed using resting state functional magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy in the right anterior insula, before and after treatment. Results Fibromyalgia patients who received EA therapy experienced a greater reduction in pain severity, as measured by the BPI, compared to patients who received ML therapy (mean difference in BPI from pre- to posttreatment was -1.14 in the EA group versus -0.46 in the ML group; P for group × time interaction = 0.036). Participants receiving EA treatment, as compared to ML treatment, also exhibited resting functional connectivity between the primary somatosensory cortical representation of the leg (S1leg ; i.e. primary somatosensory subregion activated by EA) and the anterior insula. Increased S1leg -anterior insula connectivity was associated with both reduced levels of pain severity as measured by the BPI (r = -0.44, P = 0.01) and increased levels of γ-aminobutyric acid (GABA+) in the anterior insula (r = 0.48, P = 0.046) following EA therapy. Moreover, increased levels of GABA+ in the anterior insula were associated with reduced levels of pain severity as measured by the BPI (r = -0.59, P = 0.01). Finally, post-EA treatment changes in levels of GABA+ in the anterior insula mediated the relationship between changes in S1leg -anterior insula connectivity and pain severity on the BPI (bootstrap confidence interval -0.533, -0.037). Conclusion The somatosensory component of acupuncture modulates primary somatosensory functional connectivity associated with insular neurochemistry to reduce pain severity in FM.

To a first order, the Caribbean plate converges obliquely at ~2 cm/yr toward the North American plate. This transpression is partly accommodated across the island of Hispaniola by the partitioning ...

he boundary between the North American and Caribbean plates cuts EW across the island of Hispaniola. Relative motion on this part of the plate boundary is transpressional and tectonic deformation i...

The Enriquillo-Plantain Garden Fault (EPGF), one of two left-lateral transforms that define the Caribbean-North American plate boundary in Haiti, plunges beneath Lake Azuei in the eastern part of t...

The left-lateral Enriquillo-Plantain Garden Fault (EPGF) is one of two transform systems that define the Northern Caribbean plate boundary zone. Relative motion across its trace (~ 10 mm/yr) evolve...

Abyssal hills and abyssal plains makeup the majority of the seafloor, and thus cover vast amount of the Earth’s surface. Abyssal hills form in the young oceanic lithosphere near mid-ocean ridges. These elongate, ridge-parallel hills and intervening valleys provide the characteristic fabric of the recently accreted and sparsely sedimented seafloor. Near-bottom investigations document that abyssal hills owe most of their morphology to extensional faulting. Their tectonically-driven growth continues as far as ~35 km from the spreading axis, thus defining a broader plate boundary zone within which the parting plates acquire their steady-state motion. Abyssal hill morphology is sensitive to key aspects of seafloor accretion, and thus preserves accurate records of changing spreading rate, lithospheric thermal structure, and plate boundary geometry. In general, the slower the spreading rate, the larger their dimensions are. This relationship is modulated by regional variations in the thermal structure of the lithosphere, such as may be produced by proximity to hot spots, cold spots, or transform faults and non-transform ridge offsets. As divergent plate motion rafts the aging, subsiding oceanic lithosphere away from the mid-ocean ridge, abyssal hills are generally slowly buried beneath layers of sediments. However, extreme variability in sedimentation rates means that the burial of abyssal hills by sediments is not predictably related to the age of the lithosphere. In fact, the rugged fabric of the abyssal hills is transformed into the remarkably flat surface of the abyssal plains only where oceanic basins are within reach of the fast-moving turbidity currents that originate along the continental margins.

This work explores the institutional impacts at Lehman College, City University of New York, of the Teacher Renewal for Urban Science Teaching (TRUST) Project, a partnership between the American Museum of Natural History and Brooklyn and Lehman Colleges funded by the National Science Foundation. We examine the impact that TRUST had and continues to have at Lehman College through its external partnerships, the evolving natural sciences-education cultural changes within the college, changes within the departments involved, and student outcomes and reflections.

TRUST, or Teacher Renewal for Urban Science Teaching, is a National Science Foundation funded Earth science teacher preparation partnership between the American Museum of Natural History and Brooklyn and Lehman Colleges of the City University of New York. Our research and practice form a promising and replicable model for formal-informal partnership between teacher education programs and science-rich institutions such as museums, zoos, and botanical gardens. The model takes a problem-based approach to urban teacher shortages by focusing on the knowledge required for Earth science teacher certification. The initiative included two types of participants, teachers seeking Earth science certification and teacher leaders/school administrators seeking to improve science instruction in their schools. Key features of the model included new college-based courses that focus on Earth systems science and urban Earth science investigation and a two week museum-based summer institute emphasizing essential questions, in...

We analyse TOBI side-scan sonar images collected during Charles Darwin cruise CD76 in the axial valley of the Mid-Atlantic Ridge (MAR) between 27° N and 30° N (Atlantis Transform Fault). Mosaics of the two side-scan sonar swaths provide a continuous image of the axial valley and the inner valley walls along more than six second-order segments of the MAR. Tectonic and volcanic analyses reveal a high-degree intra-segment and inter-segment variability. We distinguish three types of volcanic morphologies: hummocky volcanoes or volcanic ridges, smooth, flat-topped volcanoes, and lava flows. We observe that the variations in the tectonics from one segment to another are associated with variations in the distribution of the volcanic morphologies. Some segments have more smooth volcanoes near their ends and in the discontinuities than near their mid-point, and large, hummocky axial volcanic ridges. Their tectonic deformation is usually limited to the edges of the axial valley near the inner valley walls. Other segments have smooth volcanoes distributed along their length, small axial volcanic ridges, and their axial valley floor is affected by numerous faults and fissures. We propose a model of volcano-tectonic cycles in which smooth volcanoes and lava flows are built during phases of high magmatic flux. Hummocky volcanic ridges are constructed more progressively, by extraction of magma from pockets located preferentially beneath the centre of the segments, during phases of low magma input. These cycles might result from pulses in melt migration from the mantle. Melt arrival would lead to the rapid emplacement of smooth-textured volcanic terrains, and would leave magma pockets, mostly beneath the centre of the segments where most melt is produced. During the end of the volcanic cycle magma would be extracted from these reservoirs through dikes with a low magma pressure, building hummocky volcanic ridges at low effusion rates. In extreme cases, this volcanic phase would be followed by amagmatic extension until a new magma pulse arrives from the mantle.

[1] The morphology of the flanks of the Southwest Indian Ridge holds a record of seafloor formation and abyssal hill generation at an ultraslow spreading rate. Statistical analysis of compiled bathymetry and gravity data from the flanks of the Southwest Indian Ridge from 54°E to 67°E provides estimates of abyssal hill morphologic character and inferred crustal thickness. The extent of the compiled data encompasses a spreading rate change from slow to ultraslow at ∼24 Ma, a significant inferred variation in sub-axis mantle temperature, and a patchwork of volcanic and non-volcanic seafloor, making the Southwest Indian Ridge an ideal and unique location to characterize abyssal hills generated by ultraslow spreading and to examine the effect of dramatic spreading rate change on seafloor morphology. Root mean square abyssal hill height in ultraslow spreading seafloor ranges from ∼280 m to ∼320 m and is on average ∼80 m greater than found for slow-spreading seafloor. Ultraslow spreading abyssal hill width ranges from ∼4 km to ∼12 km, averaging ∼8 km. Abyssal hill height and width increases west-to-east in both slow and ultraslow spreading seafloor, corresponding to decreasing inferred mantle temperature. Abyssal hills persist in non-volcanic seafloor and extend continuously from volcanic to non-volcanic terrains. We attribute the increase of abyssal hill height and width to strengthening of the mantle portion of the lithosphere as the result of cooler sub-axial mantle temperature and conclude that abyssal hill height is primarily controlled by the strength of the mantle component of the lithosphere rather than spreading rate.

We examine the relationship of seafloor roughness and gravity-derived crustal thickness to both spreading rate and inferred mantle temperature using statistical analysis of a multibeam bathymetry and gravity data compilation of the axis and flanks between 54°E and 67°E at the Southwest Indian Ridge (southwest Indian Ocean). Our findings indicate that root mean square values of abyssal hill heights increase from 220 ± 20 m to 300 ± 20 m along flow line corridors that transition a well-constrained full spreading rate change from slow (30 mm/yr) to ultra-slow (15 mm/yr). Mantle Bouguer gravity anomalies, however, indicate no significant change in inferred crustal thickness at the spreading rate transition. In the axis-parallel direction, roughness of both slow and ultra-slow seafloor increases from 54°E to 63°E while inferred crustal thickness and/or mantle temperature decrease. These findings have implications for the relationship between spreading rate and melt production: they suggest that mantle temperature at slow and ultra-slow ridges may play a more important role than spreading rate in determining seafloor morphology. The lack of evidence for significant crustal thinning accompanying a change from slow to ultra-slow spreading rate lends support to focused subaxial mantle upwelling models.

Continental rifts and passive continental margins show fundamental along-axis segmentation patterns that have been attributed to one or a number of different processes: extensional fault geometry, variable stretching along strike, preexisting lithospheric compositional and structural heterogeneities, oblique rifting, and the presence or absence of eruptive volcanic centers. The length and width scales of the rift stage fault-bounded basin systems change during the late evolution of the new plate boundary, and the role of magmatism may increase as rifting progresses to continental rupture. Along obliquely spreading ridges, first-order mid-ocean ridge geometries originate during the synrift stage, indicating an intimate relationship between magma production and transform fault spacing and location. The Gulf of Aden rift is a young ocean basin in which the earliest synrift to breakup structures are well exposed onshore and covered by thin sediment layers offshore. This obliquely spreading rift is considered magma-poor and has several large-offset transforms that originated during late stage rifting and control the first-order axial segmentation of the spreading ridge. Widely spaced geophysical transects of passive margins that produce only isolated 2-D images of crust and uppermost mantle structure are inadequate for evaluation of competing rift evolution models. Using closely spaced new geophysical and geological observations from the Gulf of Aden we show that rift sectors between transforms have a large internal variability over short distances (∼10 km): the ocean-continent transition (OCT) evolves from a narrow magmatic transition to wider zones where continental mantle is probably exhumed. We suggest that this small-scale variability may be explained (1) by the distribution of volcanism and (2) by the along-strike differences in time-averaged extension rate of the oblique rift system. The volcanism may be associated with (1) the long-offset Alula-Fartak Fracture Zone, which may enhance magma production on its younger side, or (2) channeled flow from the Afar plume material along the newly formed OCT and the spreading ridge. Oblique extension and/or hot spot interactions may thereby have a significant control on the styles of rifting and continental breakup and on the evolution of many magma-poor margins.

International audience; Evidence of anomalous volcanism is readily observed in the Gulf of Aden, although, much of this oceanic basin remains as yet unmapped. In this paper, we investigate the possible connection of the Afar hotspot with a major off-axis volcanic structure and its interpretation as a consequence of a the anomalous presence of melt by integrating several data sets, both published and unpublished, from the Encens-Sheba cruise, the Aden New Century (ANC) cruise and several other onshore and marine surveys. These include bathymetric, gravity, magnetic, magneto-telluric data, and rock samples. Based upon these observations, interpretations were made of seafloor morphology, gravity and magnetic models, seafloor age, geochemical analyses and tectonic setting. We discuss the possible existence of a regional melting anomaly in the Gulf of Aden area and of the probability of its connection to the Afar plume. Several models that might explain the anomalous volcanism are taken into account, such as a local melting anomaly unrelated to the Afar plume, an anomalously large volume of melt associated with seafloor spreading, and interaction of the ridge with the Afar plume. A local melting anomaly and atypical seafloor spreading prove inconsistent with our observations. Two previously proposed models of plume-ridge interactions are examined: the diffuse plume dispersion called pancaked flow and channelized along-axis flow. We conclude that the configuration and structure of this young ocean basin may have the effect of channeling material away from the Afar plume along the Aden and Sheba Ridges to produce the off-axis volcanism observed on the ridge flanks. This interpretation implies that the influence of the Afar hotspot may extend much farther eastwards into the Gulf of Aden than previously believed. The segmentation of the Gulf of Aden and the configuration of the Aden-Sheba system may provide a potential opportunity to study channeled flow of solid plume mantle from the plume along a segmented ridge and nearby continental margins.

Combinations of anesthetic agents are frequently employed to produce the desired clinical effect. No systematic study has been conducted on the effect of the combination of nitrous oxide with a potent inhalational agent such as isoflurane on sensory evoked responses.Median nerve somatosensory evoked responses from the cervical and cortical regions (SSEP), auditory brainstem responses (ABR) and flash visual evoked responses (VEP) were tested in baboons. The latency and amplitude of the major response peaks were recorded at five proportionate mixtures of isoflurane (I) and nitrous oxide (N(2)O) (0.8% I only, 0.6% I/20% N(2)O, 0.4% I/40% N(2)O, 0.2% I/60% N(2)O, and 79% N(2)O only). A similar set of experiments were also conducted with 0.8% isoflurane and 0.6% halothane. All data were normalized to 0.8% isoflurane only and Dunnett's method of analysis used to determine which mixtures deviated from the reference values with 0.8% isoflurane.Several combinations of isoflurane with nitrous oxide produced increases in latency (ABR: wave V, VEP, SSEP cervical and cortical) and decreases in amplitude (ABR: amplitude ratio V/I, VEP, cortical SSEP) from that expected if the effects were additive. No deviations were observed with combinations of isoflurane and halothane.These studies are consistent with drug synergy when isoflurane is mixed with nitrous oxide. This suggests that if these agents are considered for anesthesia when sensory evoked responses are to be monitored that the combination of these agents may produce more amplitude and latency changes than expected from a proportionate mixture of the individual agents.

Background Preventative medicine has become increasingly important in efforts to reduce the burden of chronic disease in industrialised countries. However, interventions that fail to recruit socio-economically representative samples may widen existing health inequalities. This paper explores the barriers and facilitators to engaging a socio-economically disadvantaged (SED) population in primary prevention for coronary heart disease (CHD). Methods The primary prevention element of Have a Heart Paisley (HaHP) offered risk screening to all eligible individuals. The programme employed two approaches to engaging with the community: a) a social marketing campaign and b) a community development project adopting primarily face-to-face canvassing. Individuals living in areas of SED were under-recruited via the social marketing approach, but successfully recruited via face-to-face canvassing. This paper reports on focus group discussions with participants, exploring their perceptions about and experiences of both approaches. Results Various reasons were identified for low uptake of risk screening amongst individuals living in areas of high SED in response to the social marketing campaign and a number of ways in which the face-to-face canvassing approach overcame these barriers were identified. These have been categorised into four main themes: (1) processes of engagement; (2) issues of understanding; (3) design of the screening service and (4) the priority accorded to screening. The most immediate barriers to recruitment were the invitation letter, which often failed to reach its target, and the general distrust of postal correspondence. In contrast, participants were positive about the face-to-face canvassing approach. Participants expressed a lack of knowledge and understanding about CHD and their risk of developing it and felt there was a lack of clarity in the information provided in the mailing in terms of the process and value of screening. In contrast, direct face-to-face contact meant that outreach workers could explain what to expect. Participants felt that the procedure for uptake of screening was demanding and inflexible, but that the drop-in sessions employed by the community development project had a major impact on recruitment and retention. Conclusion Socio-economically disadvantaged individuals can be hard-to-reach; engagement requires strategies tailored to the needs of the target population rather than a population-wide approach.

[1] We reconstruct the flanks of the Mid-Atlantic Ridge (MAR) between 28° and 29°N from 1 to 10 Ma at intervals of 1 Myr for the purpose of investigating evolution of young oceanic lithosphere morphology and its variation through time using an innovative method that combines seafloor subsidence correction with interpolated isochrons and rotation poles. Reconstruction results are consistent with formation of abyssal hills every 1 to 2 Myr in 2–3 Myr old lithosphere at the outer edge of the ridge mountains as a result of transition from dynamic regime near the axis to isostatic regime of the flanks. The oblique passage of structures formed at the axial valley walls through this transition zone may play a role in the development of inside corner high bathymetry. Asymmetric juxtaposition of abyssal hill morphology in reconstruction is indicative of independent formation and evolution of the morphotectonic fabric on opposing flanks. The two major factors affecting asymmetric ridge flank morphology are found to be sense of axial offset and fluctuation of magmatic activity at the segment scale. Sense of axial offset determines the relative distribution of inside and outside corner bathymetry on the flanks. Enhanced magma supply and associated segment propagation may contribute to half-spreading rate asymmetry, accretion of thicker crust, and formation of larger abyssal hills on the faster spreading flank. Consistent alignment in reconstruction of the base of the steep walls bounding inside corner bathymetry confirms that they mark the boundaries between segments on the flanks and that the deep sediment-filled basins, typically identified as discordant zones, are attributable to outside corner bathymetry.

[1] High-resolution multibeam bathymetry is used to analyze the morphotectonic fabric of a 35,000-km2 zone of the Mid-Atlantic Ridge crest between 28° and 29°N. Interpolated isochrons at 1 Myr intervals derived from a kinematic reconstruction provide a temporal framework for the structural analysis. The axial valley within the survey area is offset by three non-transform discontinuities dividing the axis into en echelon segments. The flanks display a predominantly ridge-parallel fabric of elongate abyssal hills crosscut by several discordant zones. Throughout the zone faulting is the predominant factor in generating the morphotectonic fabric. Analysis of fault scarp distribution places the limit of active tectonic deformation between 2 and 3 Ma (25 to 35 km on either side of the spreading axis). Fault scarp relief on the ridge flanks varies with a period of approximately 2 Myr which corresponds to the wavelength of abyssal hills within the area. We propose an interpretation in which abyssal hill formation occurs periodically (∼2 Myr) within the ridge mountains as the lithosphere transitions from the dynamic supported regime near the axis to the isostatic regime of the flanks at ∼2–3 Ma (∼25–35 km from the axis).

Changes in plate motion are thought to be recorded in the trend of fracture zones, even though fracture zones provide no information about the spreading rate. Using newly compiled published and unpublished magnetic data from the Southwest Indian Ridge, we calculated fi nite rotation poles for A13, A8, and A6, from which we determined a 50% decrease in spreading rate from slow to ultraslow at ca. 24 Ma not accompanied by a signifi cant change in spreading direction. This spreading rate decrease is concurrent with changes in plate motions at only two of the four adjoining plate boundaries. Finally, we discuss the possible relationships of this event with other absolute or relative plate motion events that occurred at ca. 24 Ma at the global scale.