Phase compensated optical fiber links enable high accuracy atomic clocks separated by thousands of kilometers to be compared with unprecedented statistical resolution. By searching for a daily ...variation of the frequency difference between four strontium optical lattice clocks in different locations throughout Europe connected by such links, we improve upon previous tests of time dilation predicted by special relativity. We obtain a constraint on the Robertson-Mansouri-Sexl parameter |α|≲1.1×10^{-8}, quantifying a violation of time dilation, thus improving by a factor of around 2 the best known constraint obtained with Ives-Stilwell type experiments, and by 2 orders of magnitude the best constraint obtained by comparing atomic clocks. This work is the first of a new generation of tests of fundamental physics using optical clocks and fiber links. As clocks improve, and as fiber links are routinely operated, we expect that the tests initiated in this Letter will improve by orders of magnitude in the near future.
EU agricultural reform fails on biodiversity Pe'er, G; Dicks, LV; Visconti, P ...
Science (American Association for the Advancement of Science),
06/2014, Letnik:
344, Številka:
6188
Journal Article
Recenzirano
In December 2013, the European Union (EU) enacted the reformed Common Agricultural Policy (CAP) for 2014-2020, allocating almost 40% of the EU's budget and influencing management of half of its ...terrestrial area. Many EU politicians are announcing the new CAP as "greener," but the new environmental prescriptions are so diluted that they are unlikely to benefit biodiversity. Individual Member States (MSs), however, can still use flexibility granted by the new CAP to design national plans to protect farmland habitats and species and to ensure long-term provision of ecosystem services.
We search for transient variations of the fine structure constant using data from a European network of fiber-linked optical atomic clocks. By searching for coherent variations in the recorded clock ...frequency comparisons across the network, we significantly improve the constraints on transient variations of the fine structure constant. For example, we constrain the variation to |δα/α| < 5 × 10−17 for transients of duration 103 s. This analysis also presents a possibility to search for dark matter, the mysterious substance hypothesised to explain galaxy dynamics and other astrophysical phenomena that is thought to dominate the matter density of the universe. At the current sensitivity level, we find no evidence for dark matter in the form of topological defects (or, more generally, any macroscopic objects), and we thus place constraints on certain potential couplings between the dark matter and standard model particles, substantially improving upon the existing constraints, particularly for large (≳104 km) objects.
We outline the experimental concept and key scientific capabilities of AION (Atom Interferometer Observatory and Network), a proposed experimental programme using cold strontium atoms to search for ...ultra-light dark matter, to explore gravitational waves in the mid-frequency range between the peak sensitivities of the LISA and LIGO/Virgo/ KAGRA/INDIGO/Einstein Telescope/Cosmic Explorer experiments, and to probe other frontiers in fundamental physics. AION would complement other planned searches for dark matter, as well as probe mergers involving intermediate-mass black holes and explore early-universe cosmology. AION would share many technical features with the MAGIS experimental programme, and synergies would flow from operating AION in a network with this experiment, as well as with other atom interferometer experiments such as MIGA, ZAIGA and ELGAR. Operating AION in a network with other gravitational wave detectors such as LIGO, Virgo and LISA would also offer many synergies.
Imitation and Identification in Autism Hobson, R. Peter; Lee, Anthony
Journal of child psychology and psychiatry,
19/May , Letnik:
40, Številka:
4
Journal Article
Recenzirano
This study was designed to test the prediction that adolescents with autism would have
specific limitations in imitating the “style” of another person's actions. In a series of original
tasks that ...tested the delayed imitation of novel nonsymbolic actions, 16 participants with
autism and 16 nonautistic participants group-matched for age and verbal ability were
proficient in copying goal-directed actions, but in 3 out of 4 tasks, strikingly fewer
participants with autism imitated with style with which the demonstrator executed the
actions. An additional finding was that on 2 conditions that involved copying self-orientated
actions, only 5 of the participants with autism but 15 of the 16 nonautistic participants
spontaneously adopted the orientation-to-self on at least 1 occasion. The results are
discussed with reference to theories concerning imitation deficits in autism, and with regard
to the proposal that autism involves an impairment in intersubjective contact between
affected individuals and others (Hobson, 1989, 1993; Rogers & Pennington, 1991).
Women with borderline personality disorder have conflictual interpersonal relations that may extend to disrupted patterns of interaction with their infants.
To assess how women with borderline ...personality disorder engage with their 12 to 18-month-old infants in separation-reunion episodes.
We videotaped mother-infant interactions in separation-reunion episodes of the Strange Situation test. The mothers were women with borderline personality disorder, with depression, or without psychopathological disorder. Masked ratings of maternal behaviour were made with the Atypical Maternal Behavior Instrument for Assessment and Classification.
As predicted, a higher proportion (85%) of women with borderline personality disorder than women in the comparison groups showed disrupted affective communication with their infants. They were also distinguished by the prevalence of frightened/disoriented behaviour.
Maternal borderline personality disorder is associated with dysregulated mother-infant communication.
Summary Background Clostridium difficile infection (CDI) remains an infection control challenge, especially when environmental spore contamination and suboptimal cleaning may increase transmission ...risk. Aim To substantiate the long-term effectiveness throughout a stroke rehabilitation unit (SRU) of deep cleaning and hydrogen peroxide decontamination (HPD), following a high incidence of CDI. Methods Extensive environmental sampling (342 sites on each occasion) for C. difficile using sponge wipes was performed: before and after deep cleaning with detergent/chlorine agent; immediately following HPD; and on two further occasions, 19 days and 20 weeks following HPD. C. difficile isolates underwent polymerase chain reaction ribotyping and multi-locus variable repeat analysis (MLVA). Findings C. difficile was recovered from 10.8%, 6.1%, 0.9%, 0% and 3.5% of sites at baseline, following deep cleaning, immediately after HPD, and 19 days and 20 weeks after HPD, respectively. C. difficile ribotypes recovered after deep cleaning matched those from CDI cases in the SRU during the previous 10 months. Similarly, 10/12 of the positive sites identified at 20 weeks post-HPD harboured the same C. difficile ribotype (002) and MLVA pattern as the isolate from the first post-HPD CDI case. CDI incidence number of cases on SRU per 10 months (January–October 2011) declined from 20 before to seven after the intervention. Conclusion HPD, after deep cleaning with a detergent/chlorine agent, was highly effective for removing environmental C. difficile contamination. Long-term follow-up demonstrated that a CDI symptomatic patient can rapidly recontaminate the immediate environment. Determining a role for HPD should include long-term cost-effectiveness evaluations.
We report the repeated isolation of the fungus Geosmithia argillacea from sputum samples of people with cystic fibrosis. Identification was based on morphology and DNA sequence analysis. Isolation of ...G. argillacea did not appear to be associated with clinical deterioration. The pathogenic potential of G. argillacea is discussed.
We carried out a 26-day comparison of five simultaneously operated optical clocks and six atomic fountain clocks located at INRIM, LNE-SYRTE, NPL and PTB by using two satellite-based frequency ...comparison techniques: broadband Two-Way Satellite Time and Frequency Transfer (TWSTFT) and Global Positioning System Precise Point Positioning (GPS PPP). With an enhanced statistical analysis procedure taking into account correlations and gaps in the measurement data, combined overall uncertainties in the range of 1.8 × 10−16 to 3.5 × 10−16 for the optical clock comparisons were found. The comparison of the fountain clocks yields results with a maximum relative frequency difference of 6.9 × 10−16, and combined overall uncertainties in the range of 4.8 × 10−16 to 7.7 × 10−16.
Invasive candidiasis is a condition of major medical importance. Its incidence has increased dramatically over the last 50 years, reflecting increasingly interventional standards of medical care.
...Candida spp. are regularly reported to be the fourth commonest cause of bloodstream infection, and it is perceived that the incidence of invasive
Candida spp. infections continues to increase. The global disease burden of invasive
Candida spp. infections is difficult to quantify because of wide geographic variation. Data originating from the United States indicate that mortality from candidiasis has been falling since 1989. Data from several locations have shown that the dramatic increases in
Candida spp. bloodstream infections seen during the 1980s were not sustained through the 1990s. Some authors have reported a decreasing incidence. The contribution of non-
albicans Candida spp. to invasive infection is rising. Invasive infections with
Candida spp. continue to represent a major economic burden, increasing both mortality and morbidity in an already expensive group of hospital patients. There remains much scope for ongoing and future research into the epidemiology and basic disease processes underlying these infections.
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