Molecular mechanics of cardiac myosin-binding protein C in native thick filaments

The heart's pumping capacity results from highly regulated interactions of actomyosin molecular motors. Mutations in the gene for a potential regulator of these motors, cardiac myosin-binding protein C (cMyBP-C), cause hypertrophic cardiomyopathy. However, cMyBP-C's ability to modulate cardiac contractility is not well understood. Using single-particle fluorescence imaging techniques, transgenic protein expression, proteomics, and modeling, we found that cMyBP-C slowed actomyosin motion generation in native cardiac thick filaments. This mechanical effect was localized to where cMyBP-C resides within the thick filament (i.e., the C-zones) and was modulated by phosphorylation and site-specific proteolytic degradation. These results provide molecular insight into why cMyBP-C should be considered a member of a tripartite complex with actin and myosin that allows fine tuning of cardiac muscle contraction.     

Kepler detected gravity-mode period spacings in a red giant star

Stellar interiors are inaccessible through direct observations. For this reason, helioseismologists made use of the Sun's acoustic oscillation modes to tune models of its structure. The quest to detect modes that probe the solar core has been ongoing for decades. We report the detection of mixed modes penetrating all the way to the core of an evolved star from 320 days of observations with the Kepler satellite. The period spacings of these mixed modes are directly dependent on the density gradient between the core region and the convective envelope.     

Effectiveness of copper sulphate,potassium permanganate and peracetic acid to reduce mortality and infestation of Ichthyobodo necator in channel catfish Ictalurus punctatus (Rafinesque 1818)

Ichthyobodo necator is a single‐celled biflagellate parasite, which in high density can cause significant mortality in young fish. Copper sulphate (CuSO₄), potassium permanganate (KMnO₄) and peracetic acid (PAA) were evaluated for effectiveness against ichthyobodosis. Treatments were: untreated control, 2.1 mg L^?1CuSO₄, 3.0 mg L^?1 KMnO₄, 1.5 mg L^?1 PAA and 3.0 mg L^?1 PAA, and were applied to flow‐through tanks on three consecutive days. The study was designed to simulate the flow‐through systems utilized in the commercial rearing of juvenile channel catfish (Ictalurus punctatus). Mortality was monitored daily to compare survival rate among treatments. Parasite intensity was assessed pre chemical exposure and 20–24 h after the third application to determine effectiveness of the treatment. An assessment was also done 7 days post application to investigate possible reoccurrence. Copper sulphate, KMnO₄ and PAA (3.0 mg L^?1) significantly reduced the infestation rate of I. necator. Copper sulphate significantly improved the survival of I. necator infested channel catfish after three flow‐through applications compared with the untreated control. The 3.0 mg L^?1 PAA resulted in significantly lower survival than the untreated control, the 1.5 mg L^?1 PAA and the KMnO₄ were not statistically different from the untreated control.     

Rheological properties and baking performance of rye dough as affected by transglutaminase

Since protein aggregation and formation of a continuous protein matrix in rye dough is very limited, an enzyme-induced protein aggregation method to improve the baking properties was investigated. The effects of microbial transglutaminase (TG) on the properties of rye dough were studied by rheological tests, confocal laser scanning microscopy (CSLM), standard-scale baking tests and crumb texture profile analysis. Addition of TG in the range of 0-4000 Ukg⁻¹ rye flour modified the rheological properties of rye flour dough, resulting in a progressive increase of the complex shear modulus (|G∗|) and in a decrease of the loss factor (tan δ) due to protein cross-linking or aggregation. CLSM image analysis illustrated a TG-induced increase of the size of rye protein complexes. Standard baking tests showed positive effects on loaf volume and crumb texture of rye bread with TG applied up to 500 Ukg⁻¹ rye flour. Higher levels of TG (500 U ≤ TG ≤ 4000 U) had detrimental effects on loaf volume. Increasing TG concentration resulted in an increase of crumb springiness and hardness. In conclusion, the results of this work demonstrated that TG can be used to improve the bread making performance of rye dough by creating a continuous protein network.     

耐旱和低氮胁迫玉米种质筛选技术

耐旱和低氮胁迫玉米种质的筛选是提高产量、保护自然资源及实现农业可持续发展的重要手段.本文总结了国际玉米小麦研究中心在此方面的经验,便于我们借鉴.     

Seed from the upper devonian

We present evidence proving the existence of seeds in the Upper Devonian and extending the known age of seed plants from the Lower Carboniferous (Mississippian) into the Upper Devonian.     

Attenuation and persistence of fecal indicator bacteria in vegetated buffer strips in Southern Illinois, USA

Enteric microbial pathogens originating from agricultural practices pose a serious threat to surface water quality and human health. A two-phase study was conducted in southern Illinois that examined the ability of various riparian buffer species to attenuate fecal coliform bacteria and Escherichia coli (E. coli) in overland flow, while also assessing E. coli persistence in associated buffer soils. Plots established with giant cane (Arundinaria gigantea (Walt.) Muhl.), Kentucky Bluegrass (Poa pratensis), Orchardgrass (Dactylis glomerata L.), and non-vegetated control buffers were subjected to artificial flooding with cattle (Bos taurus) manure-laden water. Mean bacteria concentrations in overland flow exiting all plots were significantly higher than concentrations found in the source slurry. To assess E. coli persistence in plots, overland flow was collected from a simulated rainfall event 4 days following slurry application, and from natural rainfall events 22, 46, 94, 97, and 111 days after the application. Overland flow exiting all plots (including non-vegetated controls) exhibited mean E. coli concentrations significantly higher than those found in the initial slurry applied. The observed concentrations may have been the result of overland flow characteristics and high levels of ambient fecal indicator bacteria (FIB) present with plots. The moist, shaded conditions created by plot vegetation may have produced prime habitat to harbor FIB. Vegetated buffer strips (VBS) may have been effective at attenuating FIB, however, performance may have been masked by the exceptionally high ambient FIB populations that were present in adjacent soils. The young age of the VBS (<1 year) may have also influenced their seemingly poor FIB attenuation. As the VBS age, increases in above and below ground vegetative material may act to increase VBS attenuation capabilities.     

How to define green adjuvants

The concept 'green adjuvants' is difficult to define. This paper formulates an answer based on two approaches. Starting from the Organisation for Economic Cooperation and Development (OECD) definition for green chemistry, production-based and environmental-impact-based definitions for green adjuvants are proposed. According to the production-based approach, adjuvants are defined as green if they are manufactured using renewable raw materials as much as possible while making efficient use of energy, preferably renewable energy. According to the environmental impact approach, adjuvants are defined as green (1) if they have a low human and environmental impact, (2) if they do not increase active ingredient environmental mobility and/or toxicity to humans and non-target organisms, (3) if they do not increase the exposure to these active substances and (4) if they lower the impact of formulated pesticides by enhancing the performance of active ingredients, thus potentially lowering the required dosage of active ingredients. Based on both approaches, a tentative definition for 'green adjuvants' is given, and future research and legislation directions are set out.