The Interstellar Neutral He haze in the heliosphere: what can we learn?

Neutral interstellar helium has been observed by the Interstellar Boundary Explorer (IBEX) since 2009, with a signal-to-noise ratio well above 1000. Because of the geometry of the observations, the signal observed from January to March each year is the easiest to identify. However, as we show via simulations, the portion of the signal in the range of intensities from 10(-3) to 10(-2) of the peak value, previously mostly left out from the analysis, may provide important information about the details of the distribution function of interstellar He gas in front of the heliosphere. In particular, these observations may inform us about possible departures of the parent interstellar He population from equilibrium. We compare the expected distribution of the signal for the canonical assumption of a single Maxwell-Boltzmann population with the distributions for a superposition of the Maxwell-Boltzmann primary population and the recently discovered Warm Breeze, and for a single primary population given by a kappa function. We identify the regions on the sky where the differences between those cases are expected to be the most visible against the background. We discuss the diagnostic potential of the fall peak of the interstellar signal, reduced by a factor of 50 due to the Compton-Getting effect but still above the detection limit of IBEX. We point out the strong energy dependence of the fall signal and suggest that searching for this signal in the data could bring an independent assessment of the low-energy measurement threshold of the IBEX-Lo sensor.

Ms. Praed. 12 (Ausst. 42) - Niederländisches Gebetbuch

Vorbesitzer: Dominikanerkloster Frankfurt am Main

Fragm. lat. I 38 - Kalendarium (Juli - Oktober), wohl mittelrheinisch

Trägerband: 'Registrum. altare S.Agnetis 1510. N.18. Latula A'; Vorbesitzer: Stadtarchiv Frankfurt am Main

Isotopic composition of foraminifera from sediments of DSDP Legs 3, 6-9, 17

Oxygen isotopic compositions of the tests of planktonic foraminifera from several Deep Sea Drilling Project sites provide a general picture of low-latitude marine temperatures from Maastrichtian time to the present. Bottom temperatures determined from the isotopic compositions of benthonic foraminifera are interpreted as being indicative of high-latitude surface temperatures. Prior to the beginning of middle Miocene time, high- and low-latitude temperatures changed in parallel fashion. Following an apparently small and short-lived drop in temperature near the Tertiary-Cretaceous boundary, temperatures remained warm and relatively constant through Paleocene and early and middle Eocene time; bottom temperatures then were on the order of 12°C. A sharp temperature drop in late Eocene time was followed by a more gradual lowering of temperature, culminating in a late Oligocene high-latitude temperature minimum of about 4°C. A temperature rise through early Miocene time was followed in middle Miocene time by a sudden divergence of high- and low-latitude temperatures: high-latitude temperatures dropped dramatically, perhaps corresponding to the onset of major glaciation in Antarctica, but low-latitude temperatures remained constant or perhaps increased. This uncoupling of high-and low-latitude temperatures is postulated to be related to the establishment of a circum-Antarctic circulation similar to that of today. A further drop in high-latitude temperatures in late Pliocene time probably signaled the onset of a major increase in polar glaciation, including extensive sea-ice formation. Early Miocene, small-amplitude (1 per mil) sympathetic fluctuations in isotopic compositions of planktonic and benthonic foraminifera have been identified. These have a period of several hundred thousand years. Superimposed upon these are much more rapid and smaller fluctuations (0.2 to 0.5 per mil) with a period of about 80000 to 90000 yr. This is similar to the period observed for Pleistocene isotopic temperature fluctuations. In low latitudes, much smaller vertical temperature gradients seem to have existed during Maastrichtian and Paleogene time than exist at present. The absence of a sharply defined thermocline during early Tertiary time is also suggested.

Horizontal profiles of longwave and shortwave radiation components over sea ice near Barrow, Alaska during the 2011 melt

An integrated instrument package for measuring and understanding the surface radiation budget of sea ice is presented, along with results from its first deployment. The setup simultaneously measures broadband fluxes of upwelling and downwelling terrestrial and solar radiation (four components separately), spectral fluxes of incident and reflected solar radiation, and supporting data such as air temperature and humidity, surface temperature, and location (GPS), in addition to photographing the sky and observed surface during each measurement. The instruments are mounted on a small sled, allowing measurements of the radiation budget to be made at many locations in the study area to see the effect of small-scale surface processes on the large-scale radiation budget. Such observations have many applications, from calibration and validation of remote sensing products to improving our understanding of surface processes that affect atmosphere-snow-ice interactions and drive feedbacks, ultimately leading to the potential to improve climate modelling of ice-covered regions of the ocean. The photographs, spectral data, and other observations allow for improved analysis of the broadband data. An example of this is shown by using the observations made during a partly cloudy day, which show erratic variations due to passing clouds, and creating a careful estimate of what the radiation budget along the observed line would have been under uniform sky conditions, clear or overcast. Other data from the setup's first deployment, in June 2011 on fast ice near Point Barrow, Alaska, are also shown; these illustrate the rapid changes of the radiation budget during a cold period that led to refreezing and new snow well into the melt season.

Pobreza y desarrollo cognitivo infantil : Posibles modalidades de abordaje

El efecto de la pobreza sobre el desarrollo cognitivo infantil, ha sido documentado por numerosos estudios científicos durante más de ocho décadas. Ambos fenómenos son complejos y multidimensionales y, por consiguiente, su relación ha sido investigada desde múltiples enfoques. En el presente trabajo se distinguen dos modalidades principales de abordaje de la relación entre pobreza y desarrollo cognitivo. En primer lugar, se consideran ciertos trabajos que realizan un abordaje directo de dicha relación, estudiando dos grupos de niños pertenecientes a diferentes niveles socioeconómicos y comparando su rendimiento cognitivo. En segundo lugar, se examinan algunas investigaciones que llevan adelante un abordaje mediado de la misma, considerando uno o más factores mediadores, a través de las cuales la pobreza influiría de modo indirecto sobre el desarrollo cognitivo infantil. Con el objetivo de examinar los aportes diferenciales de ambos enfoques (directo y mediado), se consideran algunas investigaciones contemporáneas correspondientes a los mismos, describiendo los resultados a los que arriban y algunas de sus posibles consecuencias prácticas. La revisión realizada, evidenció que en todas las investigaciones se encontró una influencia negativa significativa de la pobreza sobre el desempeño cognitivo de los niños. Específicamente, en relación al grupo de investigaciones que realizan abordajes indirectos o mediados, los resultados de la presente revisión sugirieron que la pobreza no tendría un efecto directo sobre el desarrollo cognitivo, sino que su influencia estaría mediada por los mecanismos intervinientes considerados en los diferentes estudios. Entre ellos, la estimulación cognitiva en el hogar, ejercería la influencia más importante sobre el desempeño cognitivo de los niños, seguida por la asistencia al preescolar y los estilos parentales. Asimismo, dichos estudios evidenciarían una correlación positiva entre el nivel de escolaridad materna y la estimulación que recibe el niño en el hogar. Finalmente, dada la complejidad del fenómeno de la pobreza, en el presente estudio se concluye destacando la importancia de la realización de abordajes de tipo mediado, de la relación entre pobreza y desarrollo cognitivo. La relevancia de investigaciones llevadas adelante desde este enfoque, residiría en el hecho de que el conocimiento de los mecanismos mediadores, a través de los cuales la pobreza actíoa sobre el desarrollo cognitivo, permitiría planificar el tipo de intervenciones que podrían realizarse. Es decir, la identificación de dichos mecanismos, posibilitaría hallar las vías de intervención que resulten más efectivas. Los resultados de algunas de las investigaciones revisadas, sugerirían que intervenir en el entorno del niño en lo concerniente a la estimulación cognitiva y a los estilos parentales de los adultos, resultaría más efectivo y menos costoso que hacerlo sobre el entorno físico. Por otra parte, el vínculo hallado entre la escolaridad materna y la estimulación cognitiva que recibe el niño, estaría indicando el perfil de sujetos hacia quienes deberían orientarse prioritariamente las intervenciones destinadas a mejorar la calidad de la estimulación. De este modo, el conocimiento de los factores mediadores de la pobreza sobre el desarrollo cognitivo y la identificación de poblaciones en riesgo, posibilitaría el diseño de intervenciones especificas, orientadas a potenciar el desarrollo cognitivo de dichos niños