In-phase millennial-scale glacier changes in the tropics and North Atlantic regions during the Holocene.

Based on new and published cosmic-ray exposure chronologies, we show that glacier extent in the tropical Andes and the north Atlantic regions (TANAR) varied in-phase on millennial timescales during the Holocene, distinct from other regions. Glaciers experienced an early Holocene maximum extent, followed by a strong mid-Holocene retreat and a re-advance in the late Holocene. We further explore the potential forcing of TANAR glacier variations using transient climate simulations. Since the Atlantic Meridional Overturning Circulation (AMOC) evolution is poorly represented in these transient simulations, we develop a semi-empirical model to estimate the "AMOC-corrected" temperature and precipitation footprint at regional scales. We show that variations in the AMOC strength during the Holocene are consistent with the observed glacier changes. Our findings highlight the need to better constrain past AMOC behavior, as it may be an important driver of TANAR glacier variations during the Holocene, superimposed on other forcing mechanisms.

Presence of 236U and 239,240Pu in soils from Southern Hemisphere.

236U, 239Pu and 240Pu are present in soils mainly as a result of the local- and global-fallout from the atmospheric nuclear weapons tests carried out mainly in the 1950's and 1960's. In this work we provide new data on the presence of 236U and 239,240Pu in surface soils (i.e. up to 5 cm depth) from Chile and Africa. The results were obtained by low-energy Accelerator Mass Spectrometry (AMS). In the case of the Chilean samples, 236U/239Pu atom ratios show a high variability and are in general higher than the reported value for the global fallout in the Northern Hemisphere, ranging from 0.2 to 1.5. The 236U atomic concentrations range from 3.5 × 106 to 9.1 × 106 atoms/g, and are at least two orders of magnitude lower than the reported values in the Northern Hemisphere. The measured 240Pu/239Pu atom ratio in soils from South-Africa and Mozambique are of about 0.17, in agreement with the expected one for global-fallout at those coordinates. To best knowledge of the authors the present work is the first publication on 236U concentrations and 236U/239Pu atom ratios in soils from South-America and Africa.

Marine radioecology after the Fukushima Dai-ichi nuclear accident: Are we better positioned to understand the impact of radionuclides in marine ecosystems?

This paper focuses on how a community of researchers under the COMET (CO-ordination and iMplementation of a pan European projecT for radioecology) project has improved the capacity of marine radioecology to understand at the process level the behaviour of radionuclides in the marine environment, uptake by organisms and the resulting doses after the Fukushima Dai-ichi nuclear accident occurred in 2011. We present new radioecological understanding of the processes involved, such as the interaction of waterborne radionuclides with suspended particles and sediments or the biological uptake and turnover of radionuclides, which have been better quantified and mathematically described. We demonstrate that biokinetic models can better represent radionuclide transfer to biota in non-equilibrium situations, bringing more realism to predictions, especially when combining physical, chemical and biological interactions that occur in such an open and dynamic environment as the ocean. As a result, we are readier now than we were before the FDNPP accident in terms of having models that can be applied to dynamic situations. The paper concludes with our vision for marine radioecology as a fundamental research discipline and we present a strategy for our discipline at the European and international levels. The lessons learned are presented along with their possible applicability to assess/reduce the environmental consequences of future accidents to the marine environment and guidance for future research, as well as to assure the sustainability of marine radioecology. This guidance necessarily reflects on why and where further research funding is needed, signalling the way for future investigations.

Anthropogenic 236U and 129I in the Mediterranean Sea: First comprehensive distribution and constrain of their sources.

The first basin-wide distribution of 236U/238U atom ratios and 129I concentrations is presented for the Mediterranean Sea. During the GEOTRACES GA04S-MedSeA expedition in 2013 seawater was collected from 10 vertical profiles covering the principal sub-basins of the Mediterranean Sea. The main objective was to understand the distributions of 236U and 129I in relation to the water masses, and to constrain their sources in this region. The 236U/238U atom ratios and the 129I concentrations ranged from (710±40)×10-12 to (2220±60)×10-12 and from (4.0±0.1)×107 to (13.8±0.3)×107at·kg-1, respectively. The results show that radionuclide-poor Atlantic Water is entering at the surface through the Strait of Gibraltar whereas comparably radionuclide-enriched Levantine Intermediate Water is sinking in the Eastern Basin and flowing westward at intermediate depths. Low radionuclide levels were found in the oldest water masses at about 1000-2000m depth in the Eastern Basin. At greater depths, waters were relatively enriched in 236U and 129I due to dense water formation occurring in both, the Eastern and Western Basins. The inventories of 236U and 129I cannot be explained only by global fallout from atmospheric nuclear bomb testings carried out in the 1950s and 1960s. We estimate that the liquid input of 236U from the nuclear reprocessing facility of Marcoule (France), via the Rhône river, was of the same order of magnitude than the contribution from global fallout, whereas liquid and gaseous releases of 129I from Marcoule were up to two orders of magnitude higher than global fallout. For both radionuclides, the contribution from the Chernobyl accident is found to be minor.

Rapid Holocene thinning of an East Antarctic outlet glacier driven by marine ice sheet instability.

Outlet glaciers grounded on a bed that deepens inland and extends below sea level are potentially vulnerable to 'marine ice sheet instability'. This instability, which may lead to runaway ice loss, has been simulated in models, but its consequences have not been directly observed in geological records. Here we provide new surface-exposure ages from an outlet of the East Antarctic Ice Sheet that reveal rapid glacier thinning occurred approximately 7,000 years ago, in the absence of large environmental changes. Glacier thinning persisted for more than two and a half centuries, resulting in hundreds of metres of ice loss. Numerical simulations indicate that ice surface drawdown accelerated when the otherwise steadily retreating glacier encountered a bedrock trough. Together, the geological reconstruction and numerical simulations suggest that centennial-scale glacier thinning arose from unstable grounding line retreat. Capturing these instability processes in ice sheet models is important for predicting Antarctica's future contribution to sea level change.

An excess of cosmic ray electrons at energies of 300-800 GeV.

Galactic cosmic rays consist of protons, electrons and ions, most of which are believed to be accelerated to relativistic speeds in supernova remnants. All components of the cosmic rays show an intensity that decreases as a power law with increasing energy (for example as E(-2.7)). Electrons in particular lose energy rapidly through synchrotron and inverse Compton processes, resulting in a relatively short lifetime (about 10(5) years) and a rapidly falling intensity, which raises the possibility of seeing the contribution from individual nearby sources (less than one kiloparsec away). Here we report an excess of galactic cosmic-ray electrons at energies of approximately 300-800 GeV, which indicates a nearby source of energetic electrons. Such a source could be an unseen astrophysical object (such as a pulsar or micro-quasar) that accelerates electrons to those energies, or the electrons could arise from the annihilation of dark matter particles (such as a Kaluza-Klein particle with a mass of about 620 GeV).

Hepatitis A infections in Wisconsin: trends in incidence and factors affecting surveillance, 1986-1995.

From January 1986 through December 1995, 4,143 cases of hepatitis A virus (HAV) infection were reported in Wisconsin. The annual hepatitis A incidence remained stable from 1986 through 1988, with a mean annual rate of 4.7 cases per 100,000 (endemic HAV incidence rate). During 1989-1993, the incidence of HAV infection increased with a peak in 1992 of 19 cases per 100,000 population. A large foodborne outbreak (1992) and community wide outbreaks among African American residents (1989-1993) and Native Americans residents (1991) were associated with these high rates of HAV infection. The community wide outbreaks affected different groups: among African Americans, incidence rates were highest in young adults 15-34 years old; among Native Americans rates were highest in children 5-14 years old. Approximately 2,343 (57%) patients had no apparent risk factor (e.g., international travel, contact with person with HAV infection) for acquiring HAV infection. Factors limiting control of HAV infection in Wisconsin included poor reporting by laboratories (only 19% of all reported cases were independently reported to the Wisconsin Division of Health by a laboratory and fewer than 50% of these reports were from private laboratories), incomplete reporting by Wisconsin physicians or designees (74% of cases confirmed in Wisconsin laboratories were reported in 1995), failure to submit follow-up case report forms (14% of cases), and a prolonged interval between diagnosis and follow-up (> or = 15 days for 610 cases). Efforts should be enhanced to improve the reporting of cases of HAV infection by private laboratories, particularly through the use of automated electronic reporting.

Correlation of electrical and contractile activities of the cricopharyngeus muscle in the cat.

We correlated the electrical and contractile activities of the cricopharyngeus (CP) to better understand the function of the CP and the upper esophageal sphincter (UES). In 40 decerebrate cats, we recorded resting and active tension of the CP and CP force and electromyographic (EMG) activity simultaneously during electrical stimulation of the pharyngoesophageal (PE) nerve, esophageal distension, or swallowing. In six intact cats, the change in diameter of the UES during food swallows was determined in two planes using videofluoroscopy. We found that resting tension of the CP developed quickly with stretch, and the strain-energy function, y = 6.5e3.4(z-1), fit (r = 0.94 +/- 0.06) this relationship. Active tension peaked at 1.68 +/- 0.03 times resting length, which is greater than the maximum distension during swallowing. Activation and relaxation of the CP occurred in approximately 50 and 120 ms, respectively. PE nerve stimulation bilaterally caused a force equal to approximately 90% of the summed force generated by separate stimulation of each PE nerve. The magnitude of the EMG response of the contralateral CP was approximately 18% of the ipsilateral response to unilateral PE nerve stimulation. We conclude that the CP exhibits tension throughout its physiological range of stretch. The CP functions more like a bilateral than a single contiguous muscle, and more like cardiac than striated muscle with regard to its passive elastic properties.

[Compliance with nCPAP therapy: is prediction possible?]. / Compliance bei nCPAP-Therapie: Prädiktion möglich?

Compliance of nCPAP therapy was investigated in many studies. In our study we were interested in the influence of early subjective reactions as predictive factors of nCPAP compliance. We present the first 14 patients treated with nCPAP for 4 months. Preliminary results show a significant correlation between positive early subjective statements and acceptance of nCPAP therapy after 4 months. Our data indicates that the early subjective assessment of treatment may be considered as a possible predictive factor of nCPAP compliance.