Joint Evolution of Kin Recognition and Cooperation in Spatially Structured Rhizobium Populations

In the face of costs, cooperative interactions maintained over evolutionary time present a central question in biology. What forces maintain this cooperation? Two potential ways to explain this problem are spatially structured environments (kin selection) and kin-recognition (directed benefits). In a two-locus population genetic model, we investigated the relative roles of spatial structure and kin recognition in the maintenance of cooperation among rhizobia within the rhizobia-legume mutualism. In the case where the cooperative and kin recognition loci are independently inherited, spatial structure alone maintains cooperation, while kin recognition decreases the equilibrium frequency of cooperators. In the case of coinheritance, spatial structure remains a stronger force, but kin recognition can transiently increase the frequency of cooperators. Our results suggest that spatial structure can be a dominant force in maintaining cooperation in rhizobium populations, providing a mechanism for maintaining the mutualistic nodulation trait. Further, our model generates unique and testable predictions that could be evaluated empirically within the legume-rhizobium mutualism

High beverage sugar as well as high animal protein intake at infancy may increase overweight risk at 8 years: a prospective longitudinal pilot study

<p>Abstract</p> <p>Background</p> <p>Combined effects of early exposure to beverage sugar and animal protein and later life overweight risk have not been studied.</p> <p>Methods</p> <p>A prospective longitudinal study was initiated in 2001 with 226 infants between 4 and 13 months of age. Dietary intake was assessed with a 2 day food record. Also information on infant body weight and socio-economic status was obtained at baseline. At 8 year follow-up in 2009, children were surveyed again. Main outcome measure was overweight at 8 years as defined by BMIsds > = +1.0. Also maternal BMI, present dietary intake and physical activity, were obtained by questionnaire and 2-day food record.</p> <p>Results</p> <p>At the 8 year follow up, 120 children (53%) were surveyed again. Of those, questionnaires and food records were completed for 63 children, for the other 57 children only weight and height at 8 years was available; 20 out of 120 children (17%) were self-reported overweight at 8 years of age. Unadjusted odds ratios (ORs; 95% CI) for overweight at 8 years were 1.10 (1.02, 1.18) for beverage sugar intake per one percent of energy intake and 4.06 (1.50, 11.00) for the highest tertile of animal protein intake at infancy compared to the lowest two tertiles. After adjustment for sex, age, infant weight, breastfed at intake assessment, and socio-economic status, odds ratios were 1.13 (1.03, 1.24) for beverage sugar, and 9.67 (2.56, 36.53) for highest tertile of animal protein intake. In the subgroup with completed questionnaire (n = 63) ORs were also adjusted for current maternal overweight, more than 2 months full breastfeeding, physical activity, and energy intake, but ORs remained significantly associated with overweight at 8 years.</p> <p>Conclusions</p> <p>A high intake of sugar containing beverages as well as animal protein in the first year of life may increase the risk of overweight at 8 years. The results of this pilot investigation should be confirmed in a larger cohort.</p

Markarian 421's Unusual Satellite Galaxy

We present Hubble Space Telescope (HST) imagery and photometry of the active galaxy Markarian 421 and its companion galaxy 14 arcsec to the ENE. The HST images indicate that the companion is a morphological spiral rather than elliptical as previous ground--based imaging has concluded. The companion has a bright, compact nucleus, appearing unresolved in the HST images. This is suggestive of Seyfert activity, or possibly a highly luminous compact star cluster. We also report the results of high dynamic range long-slit spectroscopy with the slit placed to extend across both galaxies and nuclei. We detect no emission lines in the companion nucleus, though there is evidence for recent star formation. Velocities derived from a number of absorption lines visible in both galaxies indicate that the two systems are probably tidally bound and thus in close physical proximity. Using the measured relative velocities, we derive a lower limit on the MKN 421 mass within the companion orbit (R \sim 10 kpc) of 5.9 \times 10^{11} solar masses, and a mass-to-light ratio of >= 17. Our spectroscopy also shows for the first time the presence of H\alpha and [NII] emission lines from the nucleus of MKN 421, providing another example of the appearance of new emission features in the previously featureless spectrum of a classical BL Lac object. We see both broad and narrow line emission, with a velocity dispersion of several thousand km s^{-1} evident in the broad lines.Comment: LaTeX (aaspp4 style), 28 pages, 8 figures, to appear in AJ. Revised text from ref. comments; new & modified figures; new photometry included; minor corrections of typos. Color version of Fig. 1 to appear in Feb. 2000 Sky & Telescop

Does disaster affect immigrant victims more than non-immigrant victims in Dutch general practice: a matched cohort study

Background: In the literature, immigrant victims appear to be more vulnerable to health effects of a disaster than indigenous victims. Most of these studies were performed without pre-disaster measurement and without using a control group. Aim: The objective of the study is to monitor differences between two groups of victims, Turkish immigrants and indigenous Dutch, in utilization and morbidity as presented in general practice after a man-made disaster. Methods: A matched cohort study was performed with pre-disaster (1 year) and post-disaster (4 years) measurements of patients from 30 general practices in Enschede. Turkish victims (N=303) and Dutch victims (N=606), matched on age, gender and socioeconomic status, were included. Main outcome measures were psychological problems and physical symptoms as recorded by the general practitioner, using the International Classification of Primary Care (ICPC). Results: The Turkish victims showed higher utilization than the Dutch victims prior to the disaster. In the 1st post-disaster year, both groups of victims showed an increase in utilization, but the increases did not differ significantly. The Turkish group showed no significantly greater increase than the Dutch group in the five most prevalent clusters of health problems (psychological, respiratory, skin, musculoskeletal, and digestive). Conclusion: The Turkish victims in general practice were as vulnerable as the Dutch victims for the effects on their health of this man-made disaster. Differences between Turkish and native Dutch victims of this man-made disaster can largely be explained by the differences that existed already before the disaster

Label-free detection of DNA hybridization based on hydration-induced tension in nucleic acid films

The properties of water at the nanoscale are crucial in many areas of biology, but the confinement of water molecules in sub-nanometre channels in biological systems has received relatively little attention. Advances in nanotechnology make it possible to explore the role played by water molecules in living systems, potentially leading to the development of ultrasensitive biosensors. Here we show that the adsorption of water by a self-assembled monolayer of single-stranded DNA on a silicon microcantilever can be detected by measuring how the tension in the monolayer changes as a result of hydration. Our approach relies on the microcantilever bending by an amount that depends on the tension in the monolayer. In particular, we find that the tension changes dramatically when the monolayer interacts with either complementary or single mismatched single-stranded DNA targets. Our results suggest that the tension is mainly governed by hydration forces in the channels between the DNA molecules and could lead to the development of a label-free DNA biosensor that can detect single mutations. The technique provides sensitivity in the femtomolar range that is at least two orders of magnitude better than that obtained previously with label-free nanomechanical biosensors and with label-dependent microarrays.D.R. acknowledges the fellowship funded by the Autonomic Community of Madrid (CAM). J.T, M.C, J.M and D.R acknowledge financial support by Spanish Ministry of Science (MEC) under grant No. TEC2006-10316 and CAM under grant No. 200550M056. C.B. acknowledges funding provided by MEC under grant No. BIO2007-67523. Work at Centro de Astrobiología was supported by European Union (EU), Instituto Nacional de Técnica Aeroespacial (INTA), MEC and CAM. All the authors acknowledge A. Cebollada, J.M. García-Martín, J. García, J.L. Costa-Kramer, M. Arroyo-Hernández and J.V. Anguita for their assistance in the gold deposition on the cantilevers.Peer reviewe

Proteomic alterations in early stage cervical cancer

Laser capture microdissection (LCM) allows the capture of cell types or welldefined structures in tissue. We compared in a semi-quantitative way the proteomes from an equivalent of 8,000 tumor cells from patients with squamous cell cervical cancer (SCC, n = 22) with healthy epithelial and stromal cells obtained from normal cervical tissue (n = 13). Proteins were enzymatically digested into peptides which were measured by high-resolution mass spectrometry and analyzed by "all-ornothing" analysis, Bonferroni, and Benjamini-Hochberg correction for multiple testing. By comparing LCM cell type preparations, 31 proteins were exclusively found in early stage cervical cancer (n = 11) when compared with healthy epithelium and stroma, based on criteria that address specificity in a restrictive "all-or-nothing" way. By Bonferroni correction for multiple testing, 30 proteins were significantly up-regulated between early stage cervical cancer and healthy control, including six members of the MCM protein family. MCM proteins are involved in DNA repair and expected to be participating in the early stage of cancer. After a less stringent Benjamini-Hochberg correction for multiple testing, we found that the abundances of 319 proteins were significantly different between early stage cervical cancer and healthy controls. Four proteins were confirmed in digests of whole tissue lysates by Parallel Reaction

The need to promote sleep health in public health agendas across the globe.

Healthy sleep is essential for physical and mental health, and social wellbeing; however, across the globe, and particularly in developing countries, national public health agendas rarely consider sleep health. Sleep should be promoted as an essential pillar of health, equivalent to nutrition and physical activity. To improve sleep health across the globe, a focus on education and awareness, research, and targeted public health policies are needed. We recommend developing sleep health educational programmes and awareness campaigns; increasing, standardising, and centralising data on sleep quantity and quality in every country across the globe; and developing and implementing sleep health policies across sectors of society. Efforts are needed to ensure equity and inclusivity for all people, particularly those who are most socially and economically vulnerable, and historically excluded

Prolonged Antibiotic Treatment does not Prevent Intra-Abdominal Abscesses in Perforated Appendicitis

Contains fulltext : 89619.pdf (publisher's version ) (Open Access)BACKGROUND: Children with perforated appendicitis have a relatively high risk of intra-abdominal abscesses. There is no evidence that prolonged antibiotic treatment after surgery reduces intra-abdominal abscess formation. We compared two patient groups with perforated appendicitis with different postoperative antibiotic treatment protocols. METHODS: We retrospectively reviewed patients younger than age 18 years who underwent appendectomy for perforated appendicitis at two academic hospitals between January 1992 and December 2006. Perforation was diagnosed during surgery and confirmed during histopathological evaluation. Patients in hospital A received 5 days of antibiotics postoperatively, unless decided otherwise on clinical grounds. Patients in hospital B received antibiotics for 5 days, continued until serum C-reactive protein (CRP) was <20 mg/l. Univariate logistic regression analysis was performed on intention-to-treat basis. p < 0.05 was considered significant. RESULTS: A total of 149 children underwent appendectomy for perforated appendicitis: 68 in hospital A, and 81 in hospital B. As expected, the median (range) use of antibiotics was significantly different: 5 (range, 1-16) and 7 (range, 2-32) days, respectively (p < 0.0001). However, the incidence of postoperative intra-abdominal abscesses was similar (p = 0.95). Regression analysis demonstrated that sex (female) was a risk factor for abscess formation, whereas surgical technique and young age were not. CONCLUSIONS: Prolonged use of antibiotics after surgery for perforated appendicitis in children based on serum CRP does not reduce postoperative abscess formation.1 december 201