3,121 research outputs found
Gardons Notre Amour Pour Le Retour Des Vainqueurs : Keep The Home Fires Burning
https://digitalcommons.library.umaine.edu/mmb-vp/1490/thumbnail.jp
Mon soldat = (My soldier lad)
https://digitalcommons.library.umaine.edu/mmb-vp/2132/thumbnail.jp
Comparison of the wing polyphenic response of pea aphids (\u3ci\u3eAcyrthosiphon pisum\u3c/i\u3e) to crowding and predator cues
1. Pea aphids (Acyrthosiphon pisum Harris; Hemiptera: Aphididae) exhibit transgenerational wing polyphenism, in which unwinged females produce genetically identical winged offspring in response to environmental cues such as overcrowding and predation risk that indicate poor habitat quality.
2. Laboratory experiments were carried out to explore the intensity of the wing polyphenic response of pea aphids exposed to cues from ladybird predators and crowding, and their response was compared to pea aphids that were not exposed to any cues (control).
3. The study used cues from two different ladybird species: Coccinella septempunctata L. (Coleoptera: Coccinellidae) and Hippodamia convergens Guérin-Méneville (Coleoptera: Coccinellidae) to investigate whether the wing polyphenic response of pea aphids to predator cues can be generalized
4. The intensity of the wing polyphenic response of pea aphids to crowding was found to be much stronger than their response to predator cues. There was no response to H. convergens cues and the response to C. septempunctata cues was mixed
Functional muscle hypertrophy by increased insulin-like growth factor 1 does not require dysferlin.
IntroductionDysferlin loss-of-function mutations cause muscular dystrophy, accompanied by impaired membrane repair and muscle weakness. Growth promoting strategies including insulin-like growth factor 1 (IGF-1) could provide benefit but may cause strength loss or be ineffective. The objective of this study was to determine whether locally increased IGF-1 promotes functional muscle hypertrophy in dysferlin-null (Dysf-/- ) mice.MethodsMuscle-specific transgenic expression and postnatal viral delivery of Igf1 were used in Dysf-/- and control mice. Increased IGF-1 levels were confirmed by enzyme-linked immunosorbent assay. Testing for skeletal muscle mass and function was performed in male and female mice.ResultsMuscle hypertrophy occurred in response to increased IGF-1 in mice with and without dysferlin. Male mice showed a more robust response compared with females. Increased IGF-1 did not cause loss of force per cross-sectional area in Dysf-/- muscles.DiscussionWe conclude that increased local IGF-1 promotes functional hypertrophy when dysferlin is absent and reestablishes IGF-1 as a potential therapeutic for dysferlinopathies
Benzoylamidoacetonitrile is bound as a thioimidate in the active site of papain.
13C NMR spectroscopy has been used to demonstrate that 13CN-labeled benzoylamidoacetonitrile forms a covalent adduct with the thiol group of cysteine 25 in the active site of papain. Spectral comparison with model compounds indicates that the adduct is a thioimidate. On the basis of a proposed mechanism for the formation of the thioimidate, it is concluded that the -CH2C(= NH)S--imino nitrogen does not sit in the active site in the same manner as the thiol ester carbonyl oxygen of the thiol acyl enzyme (or the oxyanion of the tetrahedral intermediate). Thus, in this sense the stabilization of the thioimidate does not reflect a similarity in structure between the bound thioimidate and the transition state
The cellular interactions of PEGylated gold nanoparticles : effect of PEGylation on cellular uptake and cytotoxicity
Poly(ethylene glycol) (PEG) is frequently used to coat various medical nanoparticles (NPs). As PEG is known to minimize NP interactions with biological specimens, the question remains whether PEGylated NPs are intrinsically less toxic or whether this is caused by reduced NP uptake. In the present work, the effect of gold NP PEGylation on uptake by three cell types is compared and evaluated the effect on cell viability, oxidative stress, cell morphology, and functionality using a multiparametric methodology. The data reveal that PEGylation affects cellular NP uptake in a cell-type-dependent manner and influences toxicity by different mechanisms. At similar intracellular NP numbers, PEGylated NPs are found to yield higher levels of cell death, mostly by induction of oxidative stress. These findings reveal that PEGylation significantly reduces NP uptake, but that at similar functional (= cell-associated) NP levels, non-PEGylated NPs are better tolerated by the cells
Reconstruction of source location in a network of gravitational wave interferometric detectors
This paper deals with the reconstruction of the direction of a gravitational
wave source using the detection made by a network of interferometric detectors,
mainly the LIGO and Virgo detectors. We suppose that an event has been seen in
coincidence using a filter applied on the three detector data streams. Using
the arrival time (and its associated error) of the gravitational signal in each
detector, the direction of the source in the sky is computed using a chi^2
minimization technique. For reasonably large signals (SNR>4.5 in all
detectors), the mean angular error between the real location and the
reconstructed one is about 1 degree. We also investigate the effect of the
network geometry assuming the same angular response for all interferometric
detectors. It appears that the reconstruction quality is not uniform over the
sky and is degraded when the source approaches the plane defined by the three
detectors. Adding at least one other detector to the LIGO-Virgo network reduces
the blind regions and in the case of 6 detectors, a precision less than 1
degree on the source direction can be reached for 99% of the sky.Comment: Accepted in Phys. Rev.
Association of Machine Learning–Based Predictions of Medial Knee Contact Force With Cartilage Loss Over 2.5 Years in Knee Osteoarthritis
Objective: The relationship between in vivo knee load predictions and longitudinal cartilage changes has not been investigated. We undertook this study to develop an equation to predict the medial tibiofemoral contact force (MCF) peak during walking in persons with instrumented knee implants, and to apply this equation to determine the relationship between the predicted MCF peak and cartilage loss in patients with knee osteoarthritis (OA).
Methods: In adults with knee OA (39 women, 8 men; mean ± SD age 61.1 ± 6.8 years), baseline biomechanical gait analyses were performed, and annualized change in medial tibial cartilage volume (mm3 /year) over 2.5 years was determined using magnetic resonance imaging. In a separate sample of patients with force-measuring tibial prostheses (3 women, 6 men; mean ± SD age 70.3 ± 5.2 years), gait data plus in vivo knee loads were used to develop an equation to predict the MCF peak using machine learning. This equation was then applied to the knee OA group, and the relationship between the predicted MCF peak and annualized cartilage volume change was determined.
Results: The MCF peak was best predicted using gait speed, the knee adduction moment peak, and the vertical knee reaction force peak (root mean square error 132.88N; R2 = 0.81, P < 0.001). In participants with knee OA, the predicted MCF peak was related to cartilage volume change (R2 = 0.35, β = -0.119, P < 0.001).
Conclusion: Machine learning was used to develop a novel equation for predicting the MCF peak from external biomechanical parameters. The predicted MCF peak was positively related to medial tibial cartilage volume loss in patients with knee OA
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