Low-noise 0.8-0.96- and 0.96-1.12-THz superconductor-insulator-superconductor mixers for the Herschel Space Observatory

Heterodyne mixers incorporating Nb SIS junctions and NbTiN-SiO/sub 2/-Al microstrip tuning circuits offer the lowest reported receiver noise temperatures to date in the 0.8-0.96- and 0.96-1.12-THz frequency bands. In particular, improvements in the quality of the NbTiN ground plane of the SIS devices' on-chip microstrip tuning circuits have yielded significant improvements in the sensitivity of the 0.96-1.12-THz mixers relative to previously presented results. Additionally, an optimized RF design incorporating a reduced-height waveguide and suspended stripline RF choke filter offers significantly larger operating bandwidths than were obtained with mixers that incorporated full-height waveguides near 1 THz. Finally, the impact of junction current density and quality on the performance of the 0.8-0.96-THz mixers is discussed and compared with measured mixer sensitivities, as are the relative sensitivities of the 0.8-0.96- and 0.96-1.12-THz mixers

Prebiotics in human digestion

Analysis of the bacterial flora is important for the characterization of fermentation events. They help the further validation of the “prebiotic index“ as fast and cost-effective screening of prebotic action within individuals or selected populations

Bromine counts from XRF scanning as an estimate of the marine organic carbon content of sediment cores

XRF sediment core scanning technology is increasingly used to quantify sediment composition. The overall good correlation between biophilic halogen bromine (Br) and sedimentary total organic carbon (TOC) potentially allows the fast estimation of down core TOC profiles by XRF scanning. In order to test this approach we present data from the Arabian Sea and a Mediterranean brine basin, comparing XRF core scanning Br data with discrete sample TOC analyses. Overall, Br counts and TOC show a clear correlation, except when stable carbon isotope and C/N data indicate intervals characterized by enhanced input of terrestrial organic matter. Hence, solid phase Br is exclusively associated with marine organic matter (MOC) and can be used as a direct estimate of this parameter after a calibration is established. High pore water Br in the brine core steepens the Br/TOC correlation but after salt correction shows a nearly identical gradient to that of the Arabian Sea cor

The Father Role as Seen by a Group of College Student Fathers

Some literature implies the modern father has abdicated his place as head of the family, but little research has been done to examine the role of the father in the modern American family. Intensive interviews of 18 college student men who each had at least two children showed that these men are very much concerned with fatherhood and participate actively in the rearing of their children. They feel the father has at least as much responsibility for the rearing of their children as the mother, possibly more. They are involved more in some dimensions of parenthood than others. Those fathers who have demanding responsibilities outside the home participate less in child care but are no less interested or concerned. These families are quite democratic; most work out child care in an equalitarian manner. For the majority, however, the father remains the final authority

Перший Всеукраїнський лінгвістичний форум молодих учених (21–23 квітня 2010 року, м. Київ)

Всеукраїнський лінгвістичний форум молодих учених «Українська мова у ХХІ столітті: традиції і новаторство» відбувся в Києві 21–23 квітня 2010 року. Його організували Інститут української мови НАН України та Рада молодих учених ІУМ НАНУ

Redox geochemical signatures in Mediterranean sapropels: Implications to constrain deoxygenation dynamics in deep-marine settings

Global warming and anthropogenic activity are boosting marine deoxygenation in many regions around the globe. Deoxygenation is a critical ocean stressor with profound implications for marine ecosystems and biogeochemical cycles. Understanding the dynamics and evolution of past deoxygenation events can enhance our knowledge of present-day and future impacts of climate change and anthropogenic pressure on marine environments. Many studies have reconstructed the evolution redox conditions of past deoxygenation events using geochemical proxies. In this regard, the present work focuses on understanding the paleoenvironmental significance of geochemical redox signals derived from the onset, evolution and termination of regional-scale deoxygenations in deep-marine settings, with a specific focus on sapropels in the Eastern Mediterranean (EM). Sapropels, rhythmic organic-rich sediments deposited in EM, offer a unique opportunity to investigate recent deoxygenation events linked to past climate changes. Sapropels serve as paleo-archives of past deoxygenation events and can provide insights into the potential impacts of ongoing climate change on marine ecosystems and biogeochemical cycles. By integrating previous sapropel geochemical studies with a detailed analysis of new geochemical data from five Quaternary sapropels (S1, S5, S6, S7 and S8) in three different EM deep-marine settings, this study enhances our understanding of the paleoenvironmental significance of geochemical redox signals produced by deoxygenation dynamics and postdepositional processes in different deep-marine settings. The study supports that certain trace elements, such as Mo, V, U, Co, and Ni, are identified as more reliable redox proxies compared to Cr, Cu, Pb, and Zn. Four recurrent geochemical intervals attributed to specific redox conditions and postdepositional processes have been identified. Moreover, internal calibration of redox proxies thresholds has been performed and demonstrates how local environmental conditions (e.g., productivity rate) and hydrogeographic features (e.g., water-depth, particulate-shuttling intensity, deep-water renewal and fluvial input) play crucial roles in controlling the authigenic uptake rates of redox-sensitive trace metals, and subsequently, redox thresholds values of geochemical redox proxies. The results also emphasize the importance of postdepositional processes to accurately interpret geochemical signals in paleoenvironmental studies. This research enhances our overall understanding of geochemical signals associated with regional-scale deoxygenation events in deep-marine settings, offering new insights into predicting biogeochemical changes in marine environments undergoing a transition towards anoxia. By comprehending the dynamics of past and present deoxygenation, we acquire valuable knowledge regarding the potential effects of climate variability in marine ecosystems

Environmental shifts in and around Lake Pannon during the Tortonian Thermal Maximum based on a multi-proxy record from the Vienna Basin (Austria, Late Miocene, Tortonian)

The Neogene Lake Pannon was the largest lake that ever existed in Europe. It attained its greatest extent during the Tortonian Thermal Maximum. For the first time, results from a detailed lake record documenting about 85 kyr of Late Miocene time in a continuously recovered, 60-m-long, clay-rich core of Lake Pannon are reported. This record includes the transition from the lake's maximum transgression into its highstand at around 10.4 Ma. The environmental development of Lake Pannon during its maximum extent is interpreted based on integrated paleontological, sedimentological, mineralogical and geochemical data. The maximum extent coincided with stable sedimentation of clay, little influx from the hinterland, low surface productivity and severe bottom-water anoxia. The clay mineralogy of the lower part of the core points to prevailing chemical weathering based on the illite/smectite ratios. Distinct Fe, Mn and Ba enrichments are interpreted to have formed close to sulfate-methane transition zones during the maximum flooding. The highstand phase was marked by rapid environmental shifts with frequent phases of well‑oxygenated bottom waters. These phases are reflected by rich benthic communities including stenohaline tunicates. The increased input of detritic kaolinite suggests a shift towards physical weathering and higher precipitation coinciding with a shift in the provenance of clay minerals. Increasing amounts of nutrients stimulated surface water productivity and nannoplankton blooms. Despite the offshore position of the core at ∼8 km from the mountainous ranges of the Alps, strong fluvial input is reflected from 32.5 to 30.3 m by coarser sediment and the occurrence of terrestrial and freshwater molluscs. The Rhenodanubian Flysch Unit was the main source of the siliciclastics of the core and was drained by the Paleo-Wien river. Drainage from the Calcareous Alps was limited to an exceptionally strong fluvial event and related deposits, which documents the presence of a second river in the southwest, which might represent the Paleo-Liesing. The dominance of smectite throughout the core suggests a temperate climate with distinct seasonality during the Tortonian Thermal Maximum. In view of the autochthonous ascidian sclerites in three samples, and assuming generally similar ecological requirements for both Pannonian and modern tunicates, we conclude a polyhaline salinity for Lake Pannon around 10.4 Ma