Compensatory saccades benefit from prediction during head impulse testing in early recovery from vestibular deafferentation

The head impulse test (HIT) can identify a deficient vestibulo-ocular reflex (VOR) by the compensatory saccade (CS) generated once the head stops moving. The inward HIT is considered safer than the outward HIT, yet might have an oculomotor advantage given that the subject would presumably know the direction of head rotation. Here, we compare CS latencies following inward (presumed predictable) and outward (more unpredictable) HITs after acute unilateral vestibular nerve deafferentation. Seven patients received inward and outward HITs delivered at six consecutive postoperative days (POD) and again at POD 30. All head impulses were recorded by portable video-oculography. CS included those occurring during (covert) or after (overt) head rotation. Inward HITs included mean CS latencies (183.48 ms ± 4.47 SE) that were consistently shorter than those generated during outward HITs in the first 6 POD (p = 0.0033). Inward HITs induced more covert saccades compared to outward HITs, acutely. However, by POD 30 there were no longer any differences in latencies or proportions of CS and direction of head rotation. Patients with acute unilateral vestibular loss likely use predictive cues of head direction to elicit early CS to keep the image centered on the fovea. In acute vestibular hypofunction, inwardly applied HITs may risk a preponderance of covert saccades, yet this difference largely disappears within 30 days. Advantages of inwardly applied HITs are discussed and must be balanced against the risk of a false-negative HIT interpretation.

Thrombosis during pregnancy: Risks, prevention, and treatment for mother and fetus--harvesting the power of omic technology, biomarkers and in vitro or in vivo models to facilitate the treatment of thrombosis

Maternal thromboembolism and a spectrum of placenta-mediated complications including the pre-eclampsia syndromes, fetal growth restriction, fetal loss, and abruption manifest a shared etiopathogenesis and predisposing risk factors. Furthermore, these maternal and fetal complications are often linked to subsequent maternal health consequences that comprise the metabolic syndrome, namely, thromboembolism, chronic hypertension, and type II diabetes. Traditionally, several lines of evidence have linked vasoconstriction, excessive thrombosis and inflammation, and impaired trophoblast invasion at the uteroplacental interface as hallmark features of the placental complications. "Omic" technologies and biomarker development have been largely based upon advances in vascular biology, improved understanding of the molecular basis and biochemical pathways responsible for the clinically relevant diseases, and increasingly robust large cohort and/or registry based studies. Advances in understanding of innate and adaptive immunity appear to play an important role in several pregnancy complications. Strategies aimed at improving prediction of these pregnancy complications are often incorporating hemodynamic blood flow data using non-invasive imaging technologies of the utero-placental and maternal circulations early in pregnancy. Some evidence suggests that a multiple marker approach will yield the best performing prediction tools, which may then in turn offer the possibility of early intervention to prevent or ameliorate these pregnancy complications. Prediction of maternal cardiovascular and non-cardiovascular consequences following pregnancy represents an important area of future research, which may have significant public health consequences not only for cardiovascular disease, but also for a variety of other disorders, such as autoimmune and neurodegenerative diseases.

In Utero Exposure to Antiretroviral Drugs: Effect on Birth Weight and Growth Among HIV-exposed Uninfected Children in Brazil.

BACKGROUND There are concerns about the effects of in utero exposure to antiretroviral drugs (ARVs) on the development of HIV-exposed but uninfected (HEU) children. The aim of this study was to evaluate whether in utero exposure to ARVs is associated with lower birth weight/height and reduced growth during the first 2 years of life. METHODS This cohort study was conducted among HEU infants born between 1996 and 2010 in Tertiary children's hospital in Rio de Janeiro, Brazil. Weight was measured by mechanical scale, and height was measured by measuring board. Z-scores for weight-for-age (WAZ), length-for-age (LAZ) and weight-for-length were calculated. We modeled trajectories by mixed-effects models and adjusted for mother's age, CD4 cell count, viral load, year of birth and family income. RESULTS A total of 588 HEU infants were included of whom 155 (26%) were not exposed to ARVs, 114 (19%) were exposed early (first trimester) and 319 (54%) later. WAZ were lower among infants exposed early compared with infants exposed later: adjusted differences were -0.52 (95% confidence interval [CI]: -0.99 to -0.04, P = 0.02) at birth and -0.22 (95% CI: -0.47 to 0.04, P = 0.10) during follow-up. LAZ were lower during follow-up: -0.35 (95% CI: -0.63 to -0.08, P = 0.01). There were no differences in weight-for-length scores. Z-scores of infants exposed late during pregnancy were similar to unexposed infants. CONCLUSIONS In HEU children, early exposure to ARVs was associated with lower WAZ at birth and lower LAZ up to 2 years of life. Growth of HEU children needs to be monitored closely.

Are there age-, strain-, and sex-differences in the prolonged exposure to methylphenidate?

Repeated treatment with psychostimulants produces behavioral sensitization that results in increased locomotor responses so that lower drug doses are required to obtain the same effect and cross-sensitization with other stimulants. Methylphenidate (MPD; Ritalin) is most frequently prescribed to treat children having attention deficit hyperactivity disorder (ADHD), a syndrome with onset in childhood characterized by high levels of inattention, hyperactivity, and impulsivity. Little is known of the consequences involving the long-term use of MPD as treatment for ADHD. This study investigates if there are age, genetic/strain, and sex differences in the prolonged exposure to MPD and cross-sensitization with amphetamine. The objective is to determine whether (a) early exposure to MPD in adolescent rats increases their sensitivity to the drug when they are adult rats, (b) there are strain and sex differences in the response to MPD, and (c) treatment with MPD in adolescent and adult Wistar-Kyoto (WKY), spontaneously hyperactive/hypertensive rat (SHR), and Sprague-Dawley (SD) rat results in cross-sensitization with amphetamine. The hypotheses are that (1) early exposure to MPD in adolescent rats increases their sensitivity to the drug when they reach adulthood, and that this hypersensitivity is dose-, strain-, and sex-dependent and (2) adult rats treated with MPD as adolescents will show a greater cross-sensitization to amphetamine than those adult rats treated with saline as adolescents, and that this cross-sensitization is dose-, strain-, and sex-dependent. The study consists of recording and evaluating locomotor activity of female and male WKY, SHR, and SD rats before and after acute and repeated MPD administration when these rats are young and as adults follows by an amphetamine treatment. Results showed that repeated treatment with MPD elicited behavioral sensitization and cross-sensitization with amphetamine in these animals. The study also found that strain and sex play a crucial role in the differentiated sensitivity to the acute and chronic effects of MPD. The development of behavioral sensitization and cross-sensitization are also dependent on the dose of MPD and the age of the rat. ^

Dengue transmission risk maps of the continental United States

Dengue fever is a strictly human and non-human primate disease characterized by a high fever, thrombocytopenia, retro-orbital pain, and severe joint and muscle pain. Over 40% of the world population is at risk. Recent re-emergence of dengue outbreaks in Texas and Florida following the re-introduction of competent Aedes mosquito vectors in the United States have raised growing concerns about the potential for increased occurrences of dengue fever outbreaks throughout the southern United States. Current deficiencies in vector control, active surveillance and awareness among medical practitioners may contribute to a delay in recognizing and controlling a dengue virus outbreak. Previous studies have shown links between low-income census tracts, high population density, and dengue fever within the United States. Areas of low-income and high population density that correlate with the distribution of Aedes mosquitoes result in higher potential for outbreaks. In this retrospective ecologic study, nine maps were generated to model U.S. census tracts’ potential to sustain dengue virus transmission if the virus was introduced into the area. Variables in the model included presence of a competent vector in the county and census tract percent poverty and population density. Thirty states, 1,188 counties, and 34,705 census tracts were included in the analysis. Among counties with Aedes mosquito infestation, the census tracts were ranked high, medium, and low risk potential for sustained transmission of the virus. High risk census tracts were identified as areas having the vector, ≥20% poverty, and ≥500 persons per square mile. Census tracts with either ≥20% poverty or ≥500 persons per square mile and have the vector present are considered moderate risk. Census tracts that have the vector present but have <20% poverty and <500 persons per square mile are considered low risk. Furthermore, counties were characterized as moderate risk if 50% or more of the census tracts in that county were rated high or moderate risk, and high risk if 25% or greater were rated high risk. Extreme risk counties, which were primarily concentrated in Texas and Mississippi, were considered having 50% or greater of the census tracts ranked as high risk. Mapping of geographic areas with potential to sustain dengue virus transmission will support surveillance efforts and assist medical personnel in recognizing potential cases. ^

Geological and geochemical characteristics of the Tersang gold deposit, Malaysia: implications for genesis and gold exploration

The Central gold belt of peninsular Malaysia comprises a number of gold deposits located in the east of the N-S striking Bentong-Raub Suture Zone. The Tersang gold deposit is one of the gold deposits in the gold belt and hosted in sandstone, rhyolite and breccia units. The deposit has an inferred resource of 528,000 ounces of gold. The geochronology of the Tersang deposit has been newly constrained by LA ICP-MS U-Pb zircon dating. The maximum depositional age of the host sedimentary rocks ranges from Early Carboniferous to Early Permian (261.5 ± 4.9 Ma to 333.5 ± 2.5 Ma) for the host sandstone and Late Triassic for the rhyolite intrusion (218.8 ± 1.7 Ma). Textural characteristics of pyrite have revealed five types including (1) Euhedral to subhedral pyrite with internal fracturing and porous cores located in the sandstone layers (pyrite 1); (2) Anhedral pyrite overgrowths on pyrite 1 and disseminated in stage 1 vein (pyrite 2); (3) Fracture-filled or vein pyrite located in stages 1 and 2 vein (pyrite 3); (4) Euhedral pyrite with internal fractures also located in stage 2 vein (pyrite 4); and (5) Subhedral clean pyrite located in the rhyolite intrusion (pyrite 5). Based on pyrite mapping and spot analyses, two main stages of gold enrichment are documented from the Tersang gold deposit. Gold in sandstone-hosted pyrite 1 (mean 4.3 ppm) shows best correlation with Bi and Pb (as evidenced on pyrite maps). In addition, gold in pyrite 3 (mean 8 ppm) located in stage 2 vein shows a good correlation with As, Ag, Sb, Cu, Tl, and Pb. In terms of gold exploration, we suggest that elements such as As, Ag, Sb, Cu, Tl, Bi, and Pb associated with Au may serve as vectoring tools in gold exploration. Our new geological, structural, geochemical and isotopic data together with mineral paragenesis, pyrite chemistry and ore fluid characteristics indicate that the Tersang gold deposit is comparable to a sediment-hosted gold deposit. Our new genetic model suggests deposition of the Permo-Carboniferous sediments followed by intrusion of rhyolitic magma in the Late Triassic. At a later stage, gold mineralisation overprinted the rhyolite intrusion and the sandstone.

Mid-Wisconsin to Holocene permafrost and landscape dynamics based on a drained lake basin core from the northern Seward Peninsula, Northwest Alaska

Permafrost-related processes drive regional landscape dynamics in the Arctic terrestrial system. A better understanding of past periods indicative of permafrost degradation and aggradation is important for predicting the future response of Arctic landscapes to climate change. Here, we used a multi-proxy approach to analyze a ~4 m long sediment core from a drained thermokarst lake basin on the northern Seward Peninsula in western Arctic Alaska (USA). Sedimentological, biogeochemistical, geochronological, micropaleontological (ostracoda, testate amoeba) and tephra analyses were used to determine the long-term environmental Early-Wisconsin to Holocene history preserved in our core for Central Beringia. Yedoma accumulation dominated throughout the Early to Late-Wisconsin but was interrupted by wetland formation from 44.5 to 41.5 ka BP. The latter was terminated by deposition of 1 m of volcanic tephra, most likely originating from the South Killeak Maar eruption at about 42 ka BP. Yedoma deposition continued until 22.5 ka BP and was followed by a depositional hiatus in the sediment core between 22.5 and 0.23 ka BP. We interpret this hiatus as due to intense thermokarst activity in the areas surrounding the site, which served as a sediment source during the Late-Wisconsin to Holocene climate transition. The lake forming the modern basin on the upland initiated around 0.23 ka BP, which drained catastrophically in spring 2005. The present study emphasizes that Arctic lake systems and periglacial landscapes are highly dynamic and permafrost formation as well as degradation in Central Beringia was controlled by regional to global climate patterns and as well as by local disturbances.

(Table 1) Sea ice and snow characteristics and heat fluxes observed during R/V Aurora Australis cruise to East Antarctica in September/October 2007

The properties of snow on East Antarctic sea ice off Wilkes Land were examined during the Sea Ice Physics and Ecosystem Experiment (SIPEX) in late winter of 2007, focusing on the interaction with sea ice. This observation includes 11 transect lines for the measurement of ice thickness, freeboard, and snow depth, 50 snow pits on 13 ice floes, and diurnal variation of surface heat flux on three ice floes. The detailed profiling of topography along the transects and the d18O, salinity, and density datasets of snow made it possible to examine the snow-sea-ice interaction quantitatively for the first time in this area. In general, the snow displayed significant heterogeneity in types, thickness (mean: 0.14 +- 0.13 m), and density (325 +- 38 kg/m**3), as reported in other East Antarctic regions. High salinity was confined to the lowest 0.1 m. Salinity and d18O data within this layer revealed that saline water originated from the surface brine of sea ice in 20% of the total sites and from seawater in 80%. From the vertical profiles of snow density, bulk thermal conductivity of snow was estimated as 0.15 W/K/m on average, only half of the value used for numerical sea-ice models. Although the upward heat flux within snow estimated with this value was significantly lower than that within ice, it turned out that a higher value of thermal conductivity (0.3 to 0.4 W/K/m) is preferable for estimating ice growth amount in current numerical models. Diurnal measurements showed that upward conductive heat flux within the snow and net long-wave radiation at the surface seem to play important roles in the formation of snow ice from slush. The detailed surface topography allowed us to compare the air-ice drag coefficients of ice and snow surfaces under neutral conditions, and to examine the possibility of the retrieval of ice thickness distribution from satellite remote sensing. It was found that overall snow cover works to enhance the surface roughness of sea ice rather than moderate it, and increases the drag coefficient by about 10%. As for thickness retrieval, mean ice thickness had a higher correlation with ice surface roughness than mean freeboard or surface elevation, which indicates the potential usefulness of satellite L-band SAR in estimating the ice thickness distribution in the seasonal sea-ice zone.

Le Goff : Balance crítico de un legado

Los primeros trabajos de Jacques Le Goff, sobre mercaderes, banqueros e intelectuales de la Edad Media, presentan cualidades que anuncian su desarrollo posterior: débil teoría económica y mayor desarrollo sobre historia de las ideas. A partir de 1964, con la publicación de La civilización del occidente medieval, se produce un cambio. Ese cambio se inscribe en una nueva orientación general de la escuela de Annales: el estudio de las mentalidades. Le Goff pretende realizar un análisis de la mentalidad del hombre medieval. Su estudio se basa principalmente en textos eruditos eclesiásticos. Se demuestra en este artículo que ese tipo de fuentes permiten acceder a la mentalidad de la parte sacerdotal de la clase de poder. De manera secundaria, Le Goff estudió fuentes literarias que permiten acercarse a la mentalidad de los caballeros. Para el análisis de los campesinos y de distintos sectores subalternos se necesitarían otro tipo de fuentes que nunca fueron utilizadas por Le Goff. Este análisis mantiene algunas semejanzas con el materialismo histórico, pero también tiene profundas diferencias con la doctrina de Marx. En base a esto se determina el alcance del legado de Le Goff

Pliocene to Pleistocene planktonic foraminiferal datum levels in the North Pacific

Continuous late Neogene planktonic foraminiferal records have been studied in the deep-sea cores of DSDP Sites 173, 310, and 296 across mid-latitudes of the North Pacific. These three sites have been correlated on the basis of planktonic foraminiferal events and major paleoclimatic/paleoceanographic intervals and tied to diatom, radiolarian, and nannofossil datum levels, and paleomagnetic and isotopic stratigraphy. Ten planktonic foraminiferal datum levels have been recognized within these Pliocene to Pleistocene sections; two of these are recognizable within the Pleistocene and eight within the Pliocene. Six planktonic foraminiferal zones are proposed which combined with the foraminiferal datum levels provide a high resolution biostratigraphic correlation for the mid-latitudes of the North Pacific.

Le Goff : Balance crítico de un legado

Los primeros trabajos de Jacques Le Goff, sobre mercaderes, banqueros e intelectuales de la Edad Media, presentan cualidades que anuncian su desarrollo posterior: débil teoría económica y mayor desarrollo sobre historia de las ideas. A partir de 1964, con la publicación de La civilización del occidente medieval, se produce un cambio. Ese cambio se inscribe en una nueva orientación general de la escuela de Annales: el estudio de las mentalidades. Le Goff pretende realizar un análisis de la mentalidad del hombre medieval. Su estudio se basa principalmente en textos eruditos eclesiásticos. Se demuestra en este artículo que ese tipo de fuentes permiten acceder a la mentalidad de la parte sacerdotal de la clase de poder. De manera secundaria, Le Goff estudió fuentes literarias que permiten acercarse a la mentalidad de los caballeros. Para el análisis de los campesinos y de distintos sectores subalternos se necesitarían otro tipo de fuentes que nunca fueron utilizadas por Le Goff. Este análisis mantiene algunas semejanzas con el materialismo histórico, pero también tiene profundas diferencias con la doctrina de Marx. En base a esto se determina el alcance del legado de Le Goff

Le Goff : Balance crítico de un legado

Los primeros trabajos de Jacques Le Goff, sobre mercaderes, banqueros e intelectuales de la Edad Media, presentan cualidades que anuncian su desarrollo posterior: débil teoría económica y mayor desarrollo sobre historia de las ideas. A partir de 1964, con la publicación de La civilización del occidente medieval, se produce un cambio. Ese cambio se inscribe en una nueva orientación general de la escuela de Annales: el estudio de las mentalidades. Le Goff pretende realizar un análisis de la mentalidad del hombre medieval. Su estudio se basa principalmente en textos eruditos eclesiásticos. Se demuestra en este artículo que ese tipo de fuentes permiten acceder a la mentalidad de la parte sacerdotal de la clase de poder. De manera secundaria, Le Goff estudió fuentes literarias que permiten acercarse a la mentalidad de los caballeros. Para el análisis de los campesinos y de distintos sectores subalternos se necesitarían otro tipo de fuentes que nunca fueron utilizadas por Le Goff. Este análisis mantiene algunas semejanzas con el materialismo histórico, pero también tiene profundas diferencias con la doctrina de Marx. En base a esto se determina el alcance del legado de Le Goff

Seagrass time-series analysis products, in Moreton Bay, Australia, with links to GeoTIFFs

The spatial and temporal dynamics of seagrasses have been well studied at the leaf to patch scales, however, the link to large spatial extent landscape and population dynamics is still unresolved in seagrass ecology. Traditional remote sensing approaches have lacked the temporal resolution and consistency to appropriately address this issue. This study uses two high temporal resolution time-series of thematic seagrass cover maps to examine the spatial and temporal dynamics of seagrass at both an inter- and intra-annual time scales, one of the first globally to do so at this scale. Previous work by the authors developed an object-based approach to map seagrass cover level distribution from a long term archive of Landsat TM and ETM+ images on the Eastern Banks (~200 km**2), Moreton Bay, Australia. In this work a range of trend and time-series analysis methods are demonstrated for a time-series of 23 annual maps from 1988 to 2010 and a time-series of 16 monthly maps during 2008-2010. Significant new insight was presented regarding the inter- and intra-annual dynamics of seagrass persistence over time, seagrass cover level variability, seagrass cover level trajectory, and change in area of seagrass and cover levels over time. Overall we found that there was no significant decline in total seagrass area on the Eastern Banks, but there was a significant decline in seagrass cover level condition. A case study of two smaller communities within the Eastern Banks that experienced a decline in both overall seagrass area and condition are examined in detail, highlighting possible differences in environmental and process drivers. We demonstrate how trend and time-series analysis enabled seagrass distribution to be appropriately assessed in context of its spatial and temporal history and provides the ability to not only quantify change, but also describe the type of change. We also demonstrate the potential use of time-series analysis products to investigate seagrass growth and decline as well as the processes that drive it. This study demonstrates clear benefits over traditional seagrass mapping and monitoring approaches, and provides a proof of concept for the use of trend and time-series analysis of remotely sensed seagrass products to benefit current endeavours in seagrass ecology.

Late Miocene to Holocene calcareous nannofossils from ODP sites of Leg 125

During Leg 125 of the Ocean Drilling Program, nine sites were drilled in the Mariana and Izu-Bonin areas. The sediments recovered range in age from early Pliocene to late Pleistocene in the Mariana Region and from middle Eocene to late Pleistocene in the Izu-Bonin region. This contribution concerns the biostratigraphic study of the latest Miocene (CN9b Subzone) to late Pleistocene interval. Aquantitative analysis of all calcareous nannofossil associations was conducted for the interval encompassing late Miocene to the top of the early Pliocene. Moreover, the genera Discoaster, Amaurolithus, and Ceratolithus were quantitatively investigated from the late Miocene to late Pliocene interval. Some bioevents were identified, and variations in the composition of assemblages were linked to climatic changes.

Early Cretaceous palynomorphes from ODP Hole 113-692B

Detailed descriptions of in situ ?Valanginian to Albian Antarctic palynofloras are presented from Weddell Sea claystones with high percentages of organic matter ("black shales") and intercalated volcanic ash layers. The claystones were recovered from two sites (ODP Leg 113, Sites 692 and 693) on the continental margin of Dronning Maud Land. Palynological investigations of these Cretaceous sediments revealed a ?Valanginian-Hauterivian age for the Site 692 sediments and an Aptian-Albian age for Site 693. This paper is focused on the palynomorphs of Site 692. Miospores, dinoflagellate cysts, and acritarchs are listed and compared with early Cretaceous microfloras from the Antarctic Peninsula, Australia, and South America. The dinocyst assemblage of Site 692 seems to be very similar in composition to an assemblage from the South Shetlands (?Valanginian-Hauterivian-Barremian). It also agrees well with associations described from early Early Cretaceous sequences from the Perth Basin, southwestern Australia. According to the Australian miospore zonation schemes, the sporomorph flora from Site 692 belongs to the South Australian Foraminisporis wonthaggiensis Zone (early Valanginian to Hauterivian) or the lower part of the dinocyst Muderongia Superzone (Valanginian to Hauterivian).