Tadpole density changes the relationship of red-eyed treefrog morphology and jumping performance [poster]

As organisms develop, increased body size is often accompanied by shape changes that alter the morphology–performance relationship. Animals with different growth histories may also have different shapes at similar body sizes. To investigate how larval growth history affects the morphology–performance relationship, we raised red-eyed treefrog tadpoles (Agalychnis callidryas) at three densities (5, 25 and 50 tadpoles per 400 L tank) and measured jump distance during metamorphosis. We predicted that tadpoles grown at low density would metamorphose into larger frogs with relatively longer legs than those grown at higher densities. We also expected low density frogs to jump further – both absolutely, because of their larger body size and relative to their size if they had longer legs. Frogs from low density had longer snout-vent lengths (SVL) than those from medium and high densities and longer tibiafibula lengths and greater masses relative to their SVL. Jump distance was strongly correlated with tibiafibula length; however, there was a significant density*tibiafibula interaction. While longer tibiafibulas in high and medium density frogs were correlated with longer jump distances, there was no such correlation in the frogs from low density tanks. We interpret these results as a consequence of the greater relative mass of the frogs from low density tanks. The relatively long legs of these frogs may not fully compensate for their disproportionately higher mass. This study demonstrates that different larval densities can change not only red-eyed treefrog morphology, but also the morphology–performance relationship. It suggests a trade-off where low larval density can increase body size and presumably fat reserves, but the latter may decrease jumping performance

Effects of hatching timing on red-eyed treefrog tadpoles: relative vulnerability varies among predators but not with hatchling age-structure, growth varies with the presence of more vulnerable tadpoles [poster]

In Gamboa, Panama, undisturbed red-eyed treefrog embryos typically hatch at age 6 days, but they can hatch as early as 4 days if attacked by egg predators. Early hatchlings are less developed and more vulnerable to predatory shrimp and fish. Here we assess the effect of hatching timing on risk of predation by three common insects, with different foraging styles, that prey on red-eyed treefrog larvae. Further, we examine whether the consequences of hatching early vary with the presence of later-hatched tadpoles. We induced hatching at 4 and 6 days and exposed tadpoles to giant water bugs or aeshnid or libellulid dragonfly larvae over 24 hrs, quantifying tadpole behavior and mortality. We used substitutive designs with three treatments: early hatched, late hatched and mixed hatching ages. In no case did presence of the other age class alter mortality. Hatching age did not affect libelullid predation, which was low in both cases. Early-hatched tadpoles had higher mortality than late hatchlings with water bugs, which move throughout the water column. In contrast, early hatchlings had lower mortality than late hatchlings with aeshnids, which cue strongly on movement. Late-hatched tadpoles were more active than early hatchlings, and movement was reduced in the presence of aeshnids. Combining across this and previously published studies, early hatchlings are more vulnerable than late hatchlings to most (3/5) predators. Variation in relative, age-specific hatchling vulnerability to predators with different foraging styles is consistent with developmental changes in tadpole behavior

The Cost of Hatching Early: Vulnerability and Exposure to Predators [poster]

Arboreal red-eyed treefrog embryos can hatch prematurely in response to egg predators. Induced early hatchlings face aquatic predators when less developed and for longer than do later hatchlings; both factors may alter survival through the high-risk early larval period. Prior work focused on developmental effects of induced hatching. In 24 h trials, less developed hatchlings were more vulnerable to three aquatic predators (shrimp, fish, water bugs) but had similar or better survival than full-term hatchlings with libellulid and aeschnid dragonfly nymphs. However, it is unknown how developmental effects and duration of exposure to predators combine to create the net effect of early hatching. Here we measured costs of early hatching over a 72 h period, from first hatching competence past peak spontaneous hatching. Embryos hatched at age 4 or 6 days were exposed to water bugs, aeshnids, or libellulids. Early-hatched tadpoles suffered higher mortality than late hatchlings with all three predators. The longer exposure of early hatchlings to aquatic predators reversed their initial phenotypic advantage with aeshnids and revealed a cost of early hatching with libellulids where none was apparent from phenotypes alone. In other experiments, early-hatched tadpoles reared without predators grew more quickly than those reared with predators cues, which grew more quickly than age-matched embryos, revealing phenotypic effects of both predator cues and the egg vs. aquatic environment. Nonetheless, any potential benefits of predator-induced phenotypes on tadpole survival were insufficient to compensate for the increased duration of predator exposure that is a consequence of hatching early. From the Conference Program at http://www.sicb.org/meetings/2011/schedule/abstractdetails.php3?id=23

Dilepton production by bremsstrahlung of meson fields in nuclear collisions

We study the bremsstrahlung of virtual omega mesons due to the collective deceleration of nuclei at the initial stage of an ultrarelativistic heavy-ion collision. It is shown that electromagnetic decays of these mesons may give an important contribution to the observed yields of dileptons. Mass spectra of positron-electron and muon pairs produced in central Au+Au collisions are calculated under some simplifying assumptions on the space-time variation of the baryonic current in a nuclear collision process. Comparison with the CERES data for 160 AGev Pb+Au collisions shows that the proposed mechanism gives a noticeable fraction of the observed lepton pairs in the intermediate region of invariant masses. Sensitivity of the dilepton yield to the in-medium modification of masses and widths of vector mesons is demonstrated.Comment: 14 page

Whole-Grain Intake, Reflected by Dietary Records and Biomarkers, Is Inversely Associated with Circulating Insulin and Other Cardiometabolic Markers in 8- to 11-Year-Old Children

Background: Whole-grain consumption seems to be cardioprotective in adults, but evidence in children is limited.Objective: We investigated whether intakes of total whole grain and dietary fiber as well as specific whole grains were associated with fat mass and cardiometabolic risk profile in children.Methods: We collected cross-sectional data on parental education, puberty, diet by 7-d records, and physical activity by accelerometry and measured anthropometry, fat mass index by dual-energy X-ray absorptiometry, and blood pressure in 713 Danish children aged 8-11 y. Fasting blood samples were obtained and analyzed for alkylresorcinols, biomarkers of whole-grain wheat and rye intake, HDL and LDL cholesterol, triacylglycerols, insulin, and glucose. Linear mixed models included puberty, parental education, physical activity, and intakes of energy, fruit and vegetables, saturated fat, and n-3 (ω-3) polyunsaturated fatty acids.Results: Median (IQR) whole-grain and dietary fiber intakes were 52 g/d (35-72 g/d) and 17 g/d (14-22 g/d), respectively. Fourteen percent of children were overweight or obese and most had low-risk cardiometabolic profiles. Dietary whole-grain and fiber intakes were not associated with fat mass index but were inversely associated with serum insulin [both P < 0.01; e.g., with 0.68 pmol/L (95% CI: 0.26, 1.10 pmol/L) lower insulin · g whole grain(-1) · MJ(-1)]. Whole-grain oat intake was inversely associated with fat mass index, systolic blood pressure, and LDL cholesterol (all P < 0.05) as well as insulin (P = 0.003), which also tended to be inversely associated with whole-grain rye intake (P = 0.11). Adjustment for fat mass index did not change the associations. The C17-to-C21 alkylresorcinol ratio, reflecting whole-grain rye to wheat intake, was inversely associated with insulin (P < 0.001).Conclusions: Higher whole-grain intake was associated with lower serum insulin independently of fat mass in 8- to 11-y-old Danish children. Whole-grain oat intake was linked to an overall protective cardiometabolic profile, and whole-grain rye intake was marginally associated with lower serum insulin. This supports whole grains as healthy dietary components in childhood. This trial was registered at clinicaltrials.gov as NCT01577277

Multi-omics signatures in new-onset diabetes predict metabolic response to dietary inulin: findings from an observational study followed by an interventional trial

AIM: The metabolic performance of the gut microbiota contributes to the onset of type 2 diabetes. However, targeted dietary interventions are limited by the highly variable inter-individual response. We hypothesized (1) that the composition of the complex gut microbiome and metabolome (MIME) differ across metabolic spectra (lean-obese-diabetes); (2) that specific MIME patterns could explain the differential responses to dietary inulin; and (3) that the response can be predicted based on baseline MIME signature and clinical characteristics. METHOD: Forty-nine patients with newly diagnosed pre/diabetes (DM), 66 metabolically healthy overweight/obese (OB), and 32 healthy lean (LH) volunteers were compared in a cross-sectional case-control study integrating clinical variables, dietary intake, gut microbiome, and fecal/serum metabolomes (16 S rRNA sequencing, metabolomics profiling). Subsequently, 27 DM were recruited for a predictive study: 3 months of dietary inulin (10 g/day) intervention. RESULTS: MIME composition was different between groups. While the DM and LH groups represented opposite poles of the abundance spectrum, OB was closer to DM. Inulin supplementation was associated with an overall improvement in glycemic indices, though the response was very variable, with a shift in microbiome composition toward a more favorable profile and increased serum butyric and propionic acid concentrations. The improved glycemic outcomes of inulin treatment were dependent on better baseline glycemic status and variables related to the gut microbiota, including the abundance of certain bacterial taxa (i.e., Blautia, Eubacterium halii group, Lachnoclostridium, Ruminiclostridium, Dialister, or Phascolarctobacterium), serum concentrations of branched-chain amino acid derivatives and asparagine, and fecal concentrations of indole and several other volatile organic compounds. CONCLUSION: We demonstrated that obesity is a stronger determinant of different MIME patterns than impaired glucose metabolism. The large inter-individual variability in the metabolic effects of dietary inulin was explained by differences in baseline glycemic status and MIME signatures. These could be further validated to personalize nutritional interventions in patients with newly diagnosed diabetes

Introducing a new ICRU report: Prescribing, recording and reporting electron beam therapy

The ICRU published several Reports about volumes and doses specifications for radiotherapy, such as the Report 29 (1978), devoted to photon and electron beam therapy. This report 29 becoming absolete, a new Report was published in 1993 for external photon beam radiotherapy, the Report 50, recommending new definitions and more accurate specifications. With electran beams specific problems are raised, and the ICRU considered suitable to prepare a special Report for them, to be published in the near future.The main features of the present draft are as follows:1.Volumes specifications in agreement with the ICRU Report 50,•Volumes to be determined before treatment planning: gross tumour volume (GTV), c1inical target volume (CTV), organs at risk volumes (OR).•Volume to be determined during treatment planning: Planning target volume (PTV).•Volumes resulting fram the treatment plan chosen: treatment volume (TV), irradiated volume (IV).In the future Report on electron beams, an additional volume is defined, the internal target volume (ITV) geometrical concept representing the volume en-compassing the c1inical target volume, taking into consideration margins due to the variations of the clinical target volume in position, shape an size. A similar concept has been extended to organs at risk, the planning organ at risk volume.2.Dose specificationThe general statements for photon beams apply:•dose at a reference point (ICRU point) situated at or near the center of the planning target volume and, when possible, near or on the central axis of the electron beam at the depth of the peak dose.•Minimal and maximal doses in the planning target volume•Dose delivered to the organs at risk•Additional information is recommended, when possible (e.g. DVH).With electron beams, the dose homogeneity expected within the PTV (± 5 to ± 10 %) requires an adaptation of the terapeutic range concept, such that the value of the isodose surface encompassing the PTV be situated between 85 % and 95 % of the reference dose. The peak absorbed dose on the beam axis should always been specified, even if it is different fram the reference dose.At last, as in Report 50, three levels of dose evaluation for reporting are considered, depending on the aim of the treatment and the data available

Is standard breast-conserving therapy (BCT) in elderly breast cancer patients justified? A prospective measurement of acute toxicity according CTC-classification

<p>Abstract</p> <p>Background</p> <p>Breast conserving therapy (BCT) is an accepted treatment for early-stage breast cancer. This study aimed to measure prospectively acute radiation-related toxicity and to create a comprehensive data base for long-term temporal analyses of 3D conformal adjuvant radiotherapy. The specific aspect of age has been neglected by traditional research. Therefore, the impact of age on acute BCT toxicity should be also specifically adressed.</p> <p>Methods</p> <p>Toxicity was measured in 109 patients at initiation (t1), during radiotherapy (t2-t7), and 6 weeks after treatment completion (t8) using a new topographic module. Organ systems were recorded in 15 scales and scored according to symptom intensity (grade 0-5) based on CTC (Common Toxicity Criteria) -classification. Radiotherapy was virtually CT-based planned and applied with 6-MeV-photons. Mean total dose was 60.1 Gy. Patients were stratified by age in 3 Groups: <50, 50-60, and >60 years.</p> <p>Results</p> <p>Registered toxicity was generally low. Mean overall-grade climbed from 0.29-0.40 (t1-t7), and dropped to 0.23 (t8). Univariate analyses revealed slightly higher toxicity in older (> 60 years) versus young patients (< 50 years) in 2 scales only: breast-symmetry (p = 0.033), and arm function (p = 0.007). However, in the scale "appetite" toxicity was higher in younger (< 50 years) versus older (> 60 years) patients (p = 0.039). Toxicity differences in all other scales were not significant. Between older (> 60 years) and midaged patients (50-60 years) no significant differences in toxicity were found. This was also true for the comparison between young (< 50 years) versus midaged patient groups (50-60 years).</p> <p>Conclusion</p> <p>The treatment concept of BCT for breast cancer is generally well tolerated. The toxicity-measurement with the new topographic module is feasible. Not modified standard treatment for BC should be performed in elderly women.</p