439 research outputs found
Catch-up growth strategies differ between body structures: interactions between age and structure-specific growth in wild nestling Alpine swifts
1. Little is known on the occurrence and magnitude of faster than normal (catch-up) growth in response to periods of undernutrition in the wild, and the extent to which different body structures compensate and over what timescales is poorly understood.
2. We investigated catch-up growth in nestling Alpine Swifts, Apus melba, by comparing nestling growth trajectories in response to a naturally occurring 1-week period of inclement weather and undernutrition with growth of nestlings reared in a good year.
3. In response to undernutrition, nestlings exhibited a hierarchy of tissues preservation and compensation, with body mass being restored quickly after the end of the period of undernutrition, acceleration of skeletal growth occurring later in development, and compensation in wing length occurring mostly due to a prolongation of growth and delayed fledging.
4. The effect of undernutrition and subsequent catch-up growth was age-dependent, with older nestlings being more resilient to undernutrition, and in turn having less need to compensate later in the development.
5. This shows that young in a free-living bird population can compensate in body mass and body size for a naturally occurring period of undernutrition, and that the timing and extent of compensation varies with age and between body structures
Programme cantonal diabète dans le canton de Vaud indicateurs pour le suivi et le baromètre : rapport final
Le Programme cantonal Diabète souhaite collecter des indicateurs afin d'objectiver son suivi et produire un Baromètre Diabète Vaud qui serait publié et distribué périodiquement à un public large. Ce rapport présente les indicateurs suggérés par l'IUMSP, mandaté afin d'établir une liste raisonnée d'indicateurs sur le diabète pour le canton de Vaud. La sélection d'indicateurs s'est faite d'après plusieurs critères, parmi lesquels la disponibilité des indicateurs actuelle et à long terme, ainsi que leur pertinence avérée par la littérature. Ce rapport décrit les résultats pour les indicateurs sélectionnés, ainsi que les informations nécessaires à leur compréhension : source, fréquence de mise à disposition, méthode de calcul, limites, références éventuelles. Parmi les indicateurs décrits dans ce rapport, certains sont proposés comme spécialement pertinents à inclure dans le futur Baromètre Diabète Vaud. Aussi, une suggestion de présentation de ces indicateurs (fiches descriptives) est articulée pour ce dernier
Tests of relativity using a microwave resonator
The frequencies of a cryogenic sapphire oscillator and a hydrogen maser are
compared to set new constraints on a possible violation of Lorentz invariance.
We determine the variation of the oscillator frequency as a function of its
orientation (Michelson-Morley test) and of its velocity (Kennedy-Thorndike
test) with respect to a preferred frame candidate. We constrain the
corresponding parameters of the Mansouri and Sexl test theory to and which is equivalent to the best previous result for the
former and represents a 30 fold improvement for the latter.Comment: 8 pages, 2 figures, submitted to Physical Review Letters (October 3,
2002
Redistribution of gastric blood flow by embolization of gastric arteries before esophagectomy.
Background. Anastomotic leak remains a common and potentially deleterious complication after esophagectomy. Preoperative embolization of the left gastric artery and splenic artery (PAE) has been suggested to lower anastomotic leak rates. We present the results of our 5-year experience with this technique.Methods. All patients undergoing PAE before esophagectomy since introduction of this technique in 2004 were compared in a 1: 2 matched-pair analysis with patients without PAE. Matching criteria were type of anastomosis, neoadjuvant treatment, comorbidity, and age. Data were derived from a retrospective chart review from 2000 to 2006 that was perpetuated as a prospective database up to date. Outcome measures were anastomotic leak, overall complications, and hospital stay.Results. Between 2000 and 2009, 102 patients underwent esophagectomy for cancer in our institution with an overall leak rate of 19% and a mortality of 8%. All 19 patients having PAE since 2004 were successfully matched 1: 2 to 38 control patients without PAE; both groups were similar regarding demographics and operation characteristics. Two PAE (11%) and 8 control patients (21%) had an anastomotic leak, but the difference was statistically not significant (p = 0.469). Overall and major complication rates for PAE and control group were 89% versus 79% (p = 0.469) and 37% versus 34% (p = 1.000), respectively. Median intensive care unit and hospital stay were 3 versus 3 days (p = 1.000) and 22 versus 17 days (p = 0.321), respectively.Conclusions. In our experience, PAE has no significant impact on complications and anastomotic leak in particular after esophagectomy. (Ann Thorac Surg 2011;91:1556-61) (C) 2011 by The Society of Thoracic Surgeon
Tumor response and outcome after reverse treatment for patients with synchronous colorectal liver metastasis: a cohort study.
The reverse treatment of patients with synchronous colorectal liver metastases (CRLM) is a sequential approach with systemic chemotherapy first, followed by liver resection, and finally, primary tumor resection. The aim of this study was to assess the feasibility, the radiological and pathological tumor response to neoadjuvant therapy, recurrence rates and long-term survival after reverse treatment in a cohort study.
Data from patients with CRLM who underwent a reverse treatment from August 2008 to October 2016 were extracted from our prospective hepato-biliary database and retrospectively analyzed for response rates and survival outcomes. Radiological tumor response was assessed by RECIST (Response Evaluation Criteria In Solid Tumor) criteria and pathological response according to TRG (Tumor Regression Grade). Disease-free and overall survival were estimated with Kaplan-Meier survival curves.
There were 44 patients with 19 rectal and 25 colonic tumors. The reverse treatment was fully completed until primary tumor resection in 41 patients (93%). Radiological assessment after chemotherapy showed 61% of complete/partial response. Pathological tumor response was major or partial in 52% of patients (TRG 1-3). Median disease-free survival after primary tumor resection was 10 months (95% CI 5-15 months). Disease-free survival at 3 and 5 years was 25% and 25%, respectively. Median overall survival was 50 months (95% CI 42-58 months). Overall survival at 3 and 5 years was 59% and 39%, respectively.
The reverse treatment approach was feasible with a high rate of patients with complete treatment sequence and offers promising long-term survival for selected patients with advanced simultaneous colorectal liver metastases
New Limits to the Drift of Fundamental Constants from Laboratory Measurements
We have remeasured the absolute - transition frequency in atomic hydrogen. A comparison with the result of the previous
measurement performed in 1999 sets a limit of Hz for the drift of
with respect to the ground state hyperfine splitting in Cs. Combining this result with the recently published
optical transition frequency in Hg against and a
microwave Rb and Cs clock comparison, we deduce separate limits
on yr and the
fractional time variation of the ratio of Rb and Cs nuclear magnetic moments
equal to
yr. The latter provides information on the temporal behavior of the
constant of strong interaction.Comment: 4 pages, 3 figures, LaTe
Optical fibers with interferometric path length stability by controlled heating for transmission of optical signals and as components in frequency standards
We present a simple method to stabilize the optical path length of an optical
fiber to an accuracy of about 1/100 of the laser wavelength. We study the
dynamic response of the path length to modulation of an electrically conductive
heater layer of the fiber. The path length is measured against the laser
wavelength by use of the Pound-Drever-Hall method; negative feedback is applied
via the heater. We apply the method in the context of a cryogenic resonator
frequency standard.Comment: Expanded introduction and outlook. 9 pages, 5 figure
Proteomics of Syntrophomonas zehnderi and Methanobacterium formicicum growing on long-chain fatty acids
Background: Conversion of long-chain fatty acids (LCFA) in anaerobic digesters relies on syntrophic relationship between acetogenic bacteria and methanogenic archaea. Conversion of unsaturated- and saturated-LCFA has been previously shown by a coculture of Syntrophomonas zehnderi and Methanobacterium formicium. Degradation of unsaturated-LCFA is rare among Syntrophomonas species; the best studied fatty acid oxidizer, S. wolfei, can only grow on saturated-LCFA.
Objectives: Major differences are expected in the pathways and enzymes involved in the degradation of unsaturated-LCFA. In this work we used proteogenomic approach to study these differences.
Methods: A draft genome of S. zehnderi was obtained by Illumina HiSeq sequencing. Genomes of S. zehnderi and S. wolfei (available at NCBI) were compared. S. zehnderi and M. formicicum co-cultures grown on oleate (unsaturated LCFA, C18:1) and on stearate (saturated LCFA, C18:0) were further studied using a proteomics approach.
Conclusions: Genomic comparison of S. zehnderi and S. wolfei revealed approximately 900 different proteins and 1200 common proteins. In the genome of S. zehnderi, two replicates of the unsaturated acyl-CoA dehydrogenase genes were identified, one of which differs considerably from the acyl-CoA gene found in S. wolfei. Proteomic analysis of S. zehnderi and M. formicium co-cultures revealed high expression levels of proteins related to the -oxidation of LCFA (up to 30% of total proteins identified). Different protein expression levels were observed during the degradation of oleate (44% unique proteins) and stearate (23% unique proteins). In addition, proteins involved in electron transfer were highly expressed, including electron transfer flavoproteins, ATP synthases and a number of hydrogenases and formate dehydrogenases
Long-distance frequency dissemination with a resolution of 10-17
We use a new technique to disseminate microwave reference signals along
ordinary optical fiber. The fractional frequency resolution of a link of 86 km
in length is 10-17 for a one day integration time, a resolution higher than the
stability of the best microwave or optical clocks. We use the link to compare
the microwave reference and a CO2/OsO4 frequency standard that stabilizes a
femtosecond laser frequency comb. This demonstrates a resolution of 3.10-14 at
1 s. An upper value of the instability introduced by the femtosecond
laser-based synthesizer is estimated as 1.10-14 at 1 s
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