Dominance of autochthonous autotrophic carbon in food webs of heterotrophic rivers

This paper addresses the river heterotrophy paradox, “How can animal biomass within riverine food webs be fueled primarily by autochthonous autotrophic production if the ecosystem as a whole is heterotrophic?”. Reviewed, stable isotope data from tropical, temperate, and arctic rivers provide evidence consistent with the revised riverine productivity model (RPM): “The primary, annual energy source supporting overall metazoan production and species diversity in mid‐ to higher‐trophic levels of most rivers (≥4th order) is autochthonous primary production entering food webs via algal‐grazer and decomposer pathways”. The revised RPM does not conflict with the heterotrophy paradox because: (a) the decomposer (microbial loop) food pathway processes most of the transported, allochthonous and autochthonous carbon and, with algal respiration in some cases, is primarily responsible for a river's heterotrophic state (P/R<1); but (b) biomass production of mid‐ to higher‐trophic levels is principally supported by an algal‐grazer (phytoplankton and benthic microalgae) pathway that is only weakly linked to the decomposer pathway. The reason the algal‐grazer pathway supports the majority of metazoan biomass is that allochthonous carbon is mostly recalcitrant, whereas carbon from autochthonous primary production, though much less plentiful, is commonly more labile (easier to assimilate), contains more energy per unit mass, and is typically preferred by metazoa.     

ACUTE EFFECTS OF MOVEMENT VELOCITY ON BLOOD LACTATE AND GROWTH HORMONE RESPONSES AFTER ECCENTRIC BENCH PRESS EXERCISE IN RESISTANCE-TRAINED MEN

This study aimed to compare the effects of different velocities of eccentric muscle actions on acute blood lactate and serum growth hormone (GH) concentrations following free weight bench press exercises performed by resistance-trained men. Sixteen healthy men were divided into two groups: slow eccentric velocity (SEV; n = 8) and fast eccentric velocity (FEV; n = 8). Both groups performed four sets of eight eccentric repetitions at an intensity of 70% of their one repetition maximum eccentric (1RMecc) test, with 2-minute rest intervals between sets. The eccentric velocity was controlled to 3 seconds per range of motion for SEV and 0.5 seconds for the FEV group. There was a significant difference (P < 0.001) in the kinetics of blood lactate removal (at 3, 6, 9, 15, and 20 min) and higher mean values for peak blood lactate (P = 0.001) for the SEV group (9.1 ± 0.5 mM) compared to the FEV group (6.1 ± 0.4 mM). Additionally, serum GH concentrations were significantly higher (P < 0.001) at 15 minutes after bench press exercise in the SEV group (1.7 ± 0.6 ng · mL⁻¹) relative to the FEV group (0.1 ± 0.0 ng · mL⁻¹). In conclusion, the velocity of eccentric muscle action influences acute responses following bench press exercises performed by resistance-trained men using a slow velocity resulting in a greater metabolic stress and hormone response.     

Phase analysis of circadian-related genes in two tissues

Background  

Recent circadian clock studies using gene expression microarray in two different tissues of mouse have revealed not all circadian-related genes are synchronized in phase or peak expression times across tissues in vivo. Instead, some circadian-related genes may be delayed by 4–8 hrs in peak expression in one tissue relative to the other. These interesting biological observations prompt a statistical question regarding how to distinguish the synchronized genes from genes that are systematically lagged in phase/peak expression time across two tissues.     

Proteomic analysis of pulmonary tissue in tail-suspended rats under simulated weightlessness

Weightlessness affects lung function and even causes certain damages to pulmonary tissue. This study used rat tail-suspension model to simulate the physiological effects of weightlessness and investigate the alterations of lung proteome, to reveal the mechanism of lung injury under weightlessness condition. Twenty male Sprague-Dawley rats were randomly divided into two groups: tail-suspended and control. Protein samples from pulmonary tissue of tail-suspended and control groups were separated by two-dimensional (2D) gel electrophoresis and analyzed with ImageMaster 2D elite software. Differentially expressed proteins were identified by high definition mass spectrometry (HDMS) in combination with database searching. Seventeen differentially expressed proteins were identified, among which 13 proteins were upregulated, and four proteins downregulated. The functions of these identified proteins can be classified into six classes related to: metabolism, oxidative stress, cellular functions, cytoskeletal proteins, signal tranduction, and protein degradation. They are mainly related to cellular energy metabolism, stress and inflammatory response, cell injury and repair, intracellular signal transduction, and other cellular functions, playing important roles in weightlessness-induced lung injury.     

陆地棉萌发至三叶期不同生育阶段耐盐特性

摘要：土壤盐渍化是一个世界性的资源问题和生态问题,盐分胁迫几乎会影响棉花所有重要的生命活动, 造成棉花的减产或其他不利影响。本试验通过对14个品棉花种（系）的萌发期耐盐性、芽期耐盐性以及两个耐盐性不同的品种（系）三叶期的耐盐性,对棉花不同时期的耐盐特性进行了研究,结果表明：棉花在不同生育阶段耐盐能力是不同的,棉花盐敏感时间是在萌发出苗期。随着生育期的延长,棉花的耐盐性是逐步提高的,进行耐盐性鉴定的最佳时期在是萌发出苗期。在三叶期,随着盐分浓度的提高,棉花苗受伤害程度逐渐增加,盐敏感性品种受伤害大于耐盐品种,在同样盐浓度胁迫条件下,耐盐性不同的品种各部分受到的伤害不同,耐盐品种（系）中棉所35受伤害程度由高到低依次为：真叶>上胚轴>子叶;盐敏感品种（系）Tamcot CAB-CS受伤害程度由高到低依次为：真叶> 子叶>上胚轴。     

On the etiology of aging

Amino acid racemization is presented as an hypothesis for the cause of aging. Effects on important biomolecules resulting from changes in their three-dimensional conformations and resulting changes in activities and specificities are discussed. Aging is viewed as a natural process associated with attaining thermodynamic equilibrium.     

Character state‐based taxa erected to accommodate fossil and extant needle stoneflies (Leuctridae – Leuctrida tax.n.) and close relatives

In order to accommodate a newly discovered fossil specimen related to a subset of extant needle stoneflies (Leuctridae sensu Zwick, 2000), we provide a comparative analysis of the wing venation of these insects, and of their close relatives, primarily based on extant material. A number of character states potentially supporting monophyletic taxa are identified, and are used to erect taxon names under the cladotypic nomenclatural procedure. We introduce a new standard definition in which the mention of the antonym of the defining character state is applied. The proposed taxa, and taxa inclusiveness, are as follows: Nemouromorpha > Capniida/Leuctrida/‘Nemouridae s.l.’, and Leuctrida > Exeleuctrida > Mioleuctrida & Eleuctrida > Collaleuctrida. This scheme allowed us to tentatively accommodate several fossil species described earlier and the new specimen, left undetermined at the genus and species levels, but assigned to Collaleuctrida. To optimize retrieval of hierarchical information, we introduce the use of ‘nec’ (Latin for ‘but not’) into the taxonomic address to indicate exclusion from a taxon. For example, Mioleuctrida nec Collaleuctrida ?yehae indicates that ?yehae can be assigned to Mioleuctrida but can also be conclusively excluded from Collaleuctrida. Based on the investigated case, it is finally argued that the cladotypic nomenclatural procedure is optimal regarding name use and numbers, and allows adequate treatment of homoplasy.