Course of psychological variables in whiplash injury--a 2-year follow-up with age, gender and education pair-matched patients

This study evaluated the course of psychological variables during a 2-year follow-up in patients after common whiplash of the cervical spine. From a sample of 117 non-selected patients with common whiplash (investigated on average 7.2 +/- 4.2 days after trauma) a total of 21 suffered trauma-related symptoms over 2 years following initial injury. These patients (symptomatic group) were compared with 21 age, gender and education pair-matched patients, who showed complete recovery from trauma-related symptoms during the 2-year follow-up (asymptomatic group). Both groups underwent standardised testing procedures (i.e., Freiburg Personality Inventory and Well-Being Scale) at referral, and at 3, 6 and 24 months. In the symptomatic group during follow-up no significant changes in rating of neck pain or headache were found. Significant differences between the groups and significant deviation of scores over time were found on the Well-Being and Nervousness Scales. There was a lack of significant difference between the groups on the Depression Scale, indicating a possible somatic basis for changes in psychological functioning in the investigated sample. With regard to scales of Extraversion or Neuroticism, there were neither significant differences between the groups nor significant deviation over time. These results highlight that patients' psychological problems are rather a consequence than a cause of somatic symptoms in whiplash.

Segregation of species-specific male attractiveness in f(2) hybrid lake Malawi cichlid fish

Among the huge radiations of haplochromine cichlid fish in Lakes Malawi and Victoria, closely related species are often reproductively isolated via female mate choice although viable fertile hybrids can be produced when females are confined only with heterospecific males. We generated F(2) hybrid males from a cross between a pair of closely related sympatric cichlid fish from Lake Malawi. Laboratory mate choice experiments using microsatellite paternity analysis demonstrated that F(2) hybrid males differed significantly in their attractiveness to females of the two parental species, indicating heritable variation in traits involved in mate choice that may contribute to reproductive isolation between these species. We found no significant correlation between male mating success and any measurement of male colour pattern. A simple quantitative genetic model of reproductive isolation suggests that there may be as few as two chromosomal regions controlling species-specific attractiveness. We propose that adaptive radiation of Lake Malawi cichlids could be facilitated by the presence of genes with major effects on mate choice and reproductive isolation.

Analysis of genetic parentage in the tawny owl (Strix aluco) reveals extra-pair paternity is low

We have investigated genetic parentage in a Swiss population of tawny owls (Strix aluco). To this end, we performed genetic analysis for six polymorphic loci of 49 avian microsatellite loci tested for cross-species amplification. We found one extra-pair young out of 137 (0.7%) nestlings in 37 families (2.7%). There was no intra-specific brood parasitism. Our results are in accordance with previous findings for other raptors and owls that genetic monogamy is the rule. Female tawny owls cannot raise offspring without a substantial contribution by their mates. Hence one favoured hypothesis is that high paternal investment in reproduction selects for behaviour that prevents cuckoldry.

Effect of echo time pair selection on quantitative analysis for adrenal tumor characterization with in-phase and opposed-phase MR imaging: initial experience

PURPOSE: To determine the effect of two pairs of echo times (TEs) for in-phase (IP) and opposed-phase (OP) 3.0-T magnetic resonance (MR) imaging on (a) quantitative analysis prospectively in a phantom study and (b) diagnostic accuracy retrospectively in a clinical study of adrenal tumors, with use of various reference standards in the clinical study. MATERIALS AND METHODS: A fat-saline phantom was used to perform IP and OP 3.0-T MR imaging for various fat fractions. The institutional review board approved this HIPAA-compliant study, with waiver of informed consent. Single-breath-hold IP and OP 3.0-T MR images in 21 patients (14 women, seven men; mean age, 63 years) with 23 adrenal tumors (16 adenomas, six metastases, one adrenocortical carcinoma) were reviewed. The MR protocol involved two acquisition schemes: In scheme A, the first OP echo (approximately 1.5-msec TE) and the second IP echo (approximately 4.9-msec TE) were acquired. In scheme B, the first IP echo (approximately 2.4-msec TE) and the third OP echo (approximately 5.8-msec TE) were acquired. Quantitative analysis was performed, and analysis of variance was used to test for differences between adenomas and nonadenomas. RESULTS: In the phantom study, scheme B did not enable discrimination among voxels that had small amounts of fat. In the clinical study, no overlap in signal intensity (SI) index values between adenomas and nonadenomas was seen (P < .05) with scheme A. However, with scheme B, no overlap in the adrenal gland SI-to-liver SI ratio between adenomas and nonadenomas was seen (P < .05). With scheme B, no overlap in adrenal gland SI index-to-liver SI index ratio between adenomas and nonadenomas was seen (P < .05). CONCLUSION: This initial experience indicates SI index is the most reliable parameter for characterization of adrenal tumors with 3.0-T MR imaging when obtaining OP echo before IP echo. When acquiring IP echo before OP echo, however, nonadenomas can be mistaken as adenomas with use of the SI index value.

Matched-pair analysis of endovascular versus open surgical repair of abdominal aortic aneurysms in young patients at low risk

PURPOSE: To compare clinical outcomes of endovascular and open aortic repair of abdominal aortic aneurysms (AAAs) in young patients at low risk. It was hypothesized that endovascular aneurysm repair (EVAR) compares favorably with open aneurysm repair (OAR) in these patients. MATERIALS AND METHODS: Twenty-five patients aged 65 years or younger with a low perioperative surgical risk profile underwent EVAR at a single institution between April 1994 and May 2007 (23 men; mean age, 62 years+/-2.8). A sex- and risk-matched control group of 25 consecutive patients aged 65 years or younger who underwent OAR was used as a control group (23 men; mean age, 59 years+/-3.9). Patient outcomes and complications were classified according to Society of Vascular Surgery/International Society for Cardiovascular Surgery reporting standards. RESULTS: Mean follow-up times were 7.1 years+/-3.2 after EVAR and 5.9 years+/-1.8 after OAR (P=.1020). Total complication rates were 20% after EVAR and 52% after OAR (P=.0378), and all complications were mild or moderate. Mean intensive care unit times were 0.2 days+/-0.4 after EVAR and 1.1 days+/-0.4 after OAR (P<.0001) and mean lengths of hospital stay were 2.3 days+/-1.0 after EVAR and 5.0 days+/-2.1 after OAR (P<.0001). Cumulative rates of long-term patient survival did not differ between EVAR and OAR (P=.144). No AAA-related deaths or aortoiliac ruptures occurred during follow-up for EVAR and OAR. In addition, no surgical conversions were necessary in EVAR recipients. Cumulative rates of freedom from secondary procedures were not significantly different between the EVAR and OAR groups (P=.418). Within a multivariable Cox proportional-hazards analysis adjusted for patient age, maximum AAA diameter, and cardiac risk score, all-cause mortality rates (odds ratio [OR], 0.125; 95% CI, 0.010-1.493; P=.100) and need for secondary procedures (OR, 5.014; 95% CI, 0.325-77.410; P=.537) were not different between EVAR and OAR. CONCLUSIONS: Results from this observational study indicate that EVAR offers a favorable alternative to OAR in young patients at low risk.

Female preference for male color is necessary and sufficient for assortative mating in 2 cichlid sister species

A critical step for speciation in the face of gene flow is the origination of reproductive isolation. The evolution of assortative mating greatly facilitates this process. Assortative mating can be mediated by one or multiple cues across an array of sensory modalities. We here explore possible cues that may underlie female mate choice in a sympatric species pair of cichlid fish from Lake Victoria, Pundamilia pundamilia and Pundamilia nyererei. Previous studies identified species-specific female preferences for male coloration, but effects of other cues could not be ruled out. Therefore, we assessed female choice in a series of experiments in which we manipulated visual (color) and chemical cues. We show that the visibility of differences in nuptial hue (i.e., either blue or red) between males of the 2 species is necessary and sufficient for assortative mating by female mate choice. Such assortment mediated by a single cue may evolve relatively quickly, but could make reproductive isolation vulnerable to environmental changes. These findings confirm the important role of female mate choice for male nuptial hue in promoting the explosive speciation of African haplochromine cichlids.

Measurement of isolated-photon pair production in pp collisions at sqrts=7 TeV with the ATLAS detector

The ATLAS experiment at the LHC has measured the production cross section of events with two isolated photons in the final state, in proton-proton collisions at root s = 7 TeV. The full data set collected in 2011, corresponding to an integrated luminosity of 4.9 fb(-1), is used. The amount of background, from hadronic jets and isolated electrons, is estimated with data-driven techniques and subtracted. The total cross section, for two isolated photons with transverse energies above 25 GeV and 22 GeV respectively, in the acceptance of the electromagnetic calorimeter (vertical bar eta vertical bar < 1.37 and 1.52 < vertical bar eta vertical bar 2.37) and with an angular separation Delta R > 0.4, is 44.0(-4.2)(+3.2) pb. The differential cross sections as a function of the di-photon invariant mass, transverse momentum, azimuthal separation, and cosine of the polar angle of the largest transverse energy photon in the Collins-Soper di-photon rest frame are also measured. The results are compared to the prediction of leading-order parton-shower and next-to-leading-order and next-to-next-to-leading-order parton-level generators.

Search for light top squark pair production in final states with leptons and b⁻ jets with the ATLAS detector in sqrts=7 TeV proton-proton collisions

The results of a search for pair production of light top squarks are presented, using 4.7 fb(-1) of root s = 7 TeV proton-proton collisions collected with the ATLAS detector at the Large Hadron Collider. This search targets top squarks with masses similar to, or lighter than, the top quark mass. Final states containing exclusively one or two leptons (e, mu), large missing transverse momentum, light-flavour jets and b-jets are used to reconstruct the top squark pair system. Event-based mass scale variables are used to separate the signal from a large t (t) over bar background. No excess over the Standard Model expectations is found. The results are interpreted in the framework of the Minimal Supersymmetric Standard Model, assuming the top squark decays exclusively to a chargino and a b-quark, while requiring different mass relationships between the Supersymmetric particles in the decay chain. Light top squarks with masses between 123-167 GeV are excluded for neutralino masses around 55 GeV.

Measurements of top quark pair relative differential cross-sections with ATLAS in pp collisions at sqrts=7 TeV

Measurements are presented of differential cross-sections for top quark pair production in pp collisions at root s = 7 TeV relative to the total inclusive top quark pair production cross-section. A data sample of 2.05 fb(-1) recorded by the ATLAS detector at the Large Hadron Collider is used. Relative differential cross-sections are derived as a function of the invariant mass, the transverse momentum and the rapidity of the top quark pair system. Events are selected in the lepton (electron or muon) + jets channel. The background-subtracted differential distributions are corrected for detector effects, normalized to the total inclusive top quark pair production cross-section and compared to theoretical predictions. The measurement uncertainties range typically between 10 % and 20 % and are generally dominated by systematic effects. No significant deviations from the Standard Model expectations are observed.

Search for pair-produced massive coloured scalars in four-jet final states with the ATLAS detector in proton-proton collisions at sqrts=7 TeV

A search for pair-produced massive coloured scalar particles decaying to a four-jet final state is performed by the ATLAS experiment at the LHC in proton-proton collisions at root s = 7 TeV. The analysed data sample corresponds to an integrated luminosity of 4.6 fb(-1). No deviation from the Standard Model is observed in the invariant mass spectrum of the two-jet pairs. A limit on the scalar gluon pair production cross section of 70 pb (10 pb) is obtained at the 95 % confidence level for a scalar gluon mass of 150 GeV (350 GeV). Interpreting these results as mass limits on scalar gluons, masses ranging from 150 GeV to 287 GeV are excluded at the 95 % confidence level.

Measurement of the top quark pair production charge asymmetry in proton-proton collisions at s√ = 7 TeV using the ATLAS detector

This paper presents a measurement of the top quark pair () production charge asymmetry A (C) using 4.7 fb(-1) of proton-proton collisions at a centre-of-mass energy root s = 7 TeV collected by the ATLAS detector at the LHC. A -enriched sample of events with a single lepton (electron or muon), missing transverse momentum and at least four high transverse momentum jets, of which at least one is tagged as coming from a b-quark, is selected. A likelihood fit is used to reconstruct the event kinematics. A Bayesian unfolding procedure is employed to estimate A (C) at the parton-level. The measured value of the production charge asymmetry is A (C) = 0.006 +/- 0.010, where the uncertainty includes both the statistical and the systematic components. Differential A (C) measurements as a function of the invariant mass, the rapidity and the transverse momentum of the system are also presented. In addition, A (C) is measured for a subset of events with large velocity, where physics beyond the Standard Model could contribute. All measurements are consistent with the Standard Model predictions.