232 research outputs found
Balanced Biochemical Reactions: A New Approach to Unify Chemical and Biochemical Thermodynamics
A novel procedure is presented which, by balancing elements and electric charge of biochemical reactions which occur at constant pH and pMg, allows assessing the thermodynamics properties of reaction ΔrG′0, ΔrH′0, ΔrS′0 and the change in binding of hydrogen and magnesium ions of these reactions. This procedure of general applicability avoids the complex calculations required by the use of the Legendre transformed thermodynamic properties of formation ΔfG′0, ΔfH′0 and ΔfS′0 hitherto considered an obligatory prerequisite to deal with the thermodynamics of biochemical reactions. As a consequence, the term “conditional” is proposed in substitution of “Legendre transformed” to indicate these thermodynamics properties. It is also shown that the thermodynamic potential G is fully adequate to give a criterion of spontaneous chemical change for all biochemical reactions and then that the use of the Legendre transformed G′ is unnecessary. The procedure proposed can be applied to any biochemical reaction, making possible to re-unify the two worlds of chemical and biochemical thermodynamics, which so far have been treated separately
Hard times for catadromous fish: the case of the European eel (Anguilla anguilla, L. 1758)
Catadromous fish species can be defined important organisms for their ecological, economical, and cultural value. Because of
a complex life cycle, catadromous fish species are exhibited to the cumulative effect of multiple anthropogenic threats that resulted
in worldwide decline since the beginning of the 20th century. Among the most iconic catadromous species, the European eel
Anguilla anguilla has aroused considerable interest, and to date, many aspects of its life cycle remain relatively unknown. Although
conspicuous efforts by the research to ensure the perpetuation of the species were conducted, the identification of the best tools to
reduce the threats that affect eels remains challenging. In this narrative review, the state of the knowledge and main threats about
the life cycle, the habitat occupancy, the recruitment, and migration patterns of the European eel have been reported
Chemical and biochemical thermodynamics reunification (IUPAC Technical Report)
Abstract
According to the 1994 IUBMB-IUPAC Joint Commission on Biochemical Nomenclature (JCBN) on chemical and biochemical reactions, two categories of thermodynamics, based on different concepts and different formalisms, are established: (i) chemical thermodynamics, which employ conventional thermodynamic potentials to deal with chemical reactions [1], [2], [3]; and (ii) biochemical thermodynamics, which employ transformed thermodynamic quantities to deal with biochemical reactions based on the formalism proposed by Alberty [4], [5], [6], [7]. We showed that the two worlds of chemical and biochemical thermodynamics, which so far have been treated separately, can be reunified within the same thermodynamic framework. The thermodynamics of chemical reactions, in which all species are explicitly considered with their atoms and charge balanced, are compared with the transformed thermodynamics generally used to treat biochemical reactions where atoms and charges are not balanced. The transformed thermodynamic quantities suggested by Alberty are obtained by a mathematical transformation of the usual thermodynamic quantities. The present analysis demonstrates that the transformed values for Δr
G′0 and Δr
H′0 can be obtained directly, without performing any transformation, by simply writing the chemical reactions with all the pseudoisomers explicitly included and the elements and charges balanced. The appropriate procedures for computing the stoichiometric coefficients for the pseudoisomers are fully explained by means of an example calculation for the biochemical ATP hydrolysis reaction. It is concluded that the analysis reunifies the "two separate worlds" of conventional thermodynamics and transformed thermodynamics
A pequena polĂtica em Nietzsche
Often, the petty politics is associated with Nietzsche‟s critique of nationalism, parliamentarism and anti-Semitism, and opposed to great politics. Because it appears only in three published passages and in two posthumous fragments, it seems devoid of a proper and complex conceptual development. We argue, however, that such aphorisms enable us a more robust argument. Related to the weakening of the will, modern petty politics derives, more refined and intensified, from the millennial project of domestication of human forces originated in the Platonic-Socratic philosophy and Christianity. Our hypothesis is that it establishes a human type based on gregarious instincts (fear, comfort, security and happiness) in order to preserve itself. Consequently, its political rationality mobilizes the human forces so that they concentrate on superfluous subjects, ideals and objectives and are unable to overcome the existential limits established by the petty people of modernity. Institutions (State, family, church, educational and labor establishments) constantly forge and educate their individuals so that they turn their attention to themselves and, therefore, become physiologically exhausted, consuming and squandering their strength through mediocrity. In other words, the modern individuals establish subjects and means in order to weaken themselves. “Powerful” is, in this gregarious sense, who can best conserve one‟s own political and moral structures. Therefore, to have more “power” one must be physiologically weaker and more cunning, causing an intensification in the processes of domestication and conservation. It creates a paradox in which the less fear and more comfort, security and happiness are desired, the more fear and less comfort, security and happiness one has. Nationalism, anti-Semitism and parliamentarism are mere consequences of this logic (similar to fanaticism, the hypocrisy of rulers and modern philosophies); but quickly become the foundation of modernity which, in its turn, is elevated constantly to new intensities of domestication and gregarism.Com frequĂŞncia, a pequena polĂtica Ă© associada Ă crĂtica de Nietzsche ao nacionalismo, ao parlamentarismo e ao antissemitismo e contraposta Ă grande polĂtica. Por constar somente em trĂŞs passagens publicadas e em dois fragmentos pĂłstumos, ela parece desprovida de um desenvolvimento conceitual prĂłprio e complexo. Sustentamos, no entanto, que tais aforismos nos possibilitam uma argumentação mais robusta. Relacionada ao enfraquecimento da vontade, a pequena polĂtica moderna se deriva, de modo mais refinado e intensificado, do projeto milenar de domesticação das forças humanas advindo da filosofia socrático-platĂ´nica e do cristianismo. Nossa hipĂłtese Ă© que ela institui um tipo humano baseado nos instintos gregários (medo, conforto, segurança e felicidade) a fim de se conservar. Para isso, sua racionalidade polĂtica mobiliza as forças humanas para que elas se concentrem em assuntos, ideais e objetivos supĂ©rfluos e se impossibilitem de superar os limites existenciais estabelecidos pelas pequenas pessoas da modernidade. As instituições (Estado, famĂlia, igreja, estabelecimentos de ensino e laborais) forjam e educam cotidianamente seus indivĂduos para que eles voltem sua atenção para elas mesmas e, desse modo, se esgotem fisiologicamente, consumindo e esbanjando suas forças por meio da mediocridade. Ou seja, os indivĂduos modernos estabelecem assuntos e meios para que eles enfraqueçam a si. “Poderoso” Ă©, nesse sentido gregário, aquele que mais pode conservar suas estruturas polĂticas e morais. Por conseguinte, para se ter mais “poder” Ă© preciso ser fisiologicamente mais fraco e mais astuto, causando uma intensificação nos processos de domesticação e conservação. Cria-se um paradoxo em que, quanto menos medo e mais conforto, segurança e felicidade se almeja, mais medo e menos conforto, segurança e felicidade se tem. O nacionalismo, o antissemitismo e o parlamentarismo sĂŁo, assim, apenas consequĂŞncias dessa lĂłgica (semelhante ao fanatismo, Ă hipocrisia dos governantes e Ă s filosofias modernas); mas que, rapidamente, se tornam o fundamento da modernidade que, por sua vez, eleva-se constantemente a novas intensidades de domesticação e de gregarismo.Dados abertos - Sucupira - Teses e dissertações (2019
Sonographic-detected joint effusion compared with physical examination in the assessment of sacroiliac joints in spondyloarthritis
When the Eel Meets Dams: Larger Dams’ Long-Term Impacts on Anguilla anguilla (L., 1758)
Diadromous fish, like the European eel Anguilla anguilla (L., 1758), are highly threatened by dams that disrupt river connectivity, consequently impeding fish movements to reach feeding and spawning habitats. In this study, variation in eel occurrence between a historical period (1940–1970) and recent data (2016–2020) was assessed throughout the Sardinian rivers’ network (more than 450 sites). Using Boosted Regression Trees (BRT) we investigated relationships between eel’s occurrence and a set of spatial and temporal environmental variables including a set of dams’ construction features for each period. An overall decrease by 65% of eel’s occurrence was noticed during the ca. 80-years period under scrutiny. Considering a subset (105 and 88 sites for the historical and the recent period, respectively) characterized by the presence of larger dams (height >15 m), eel’s occurrence dropped by 85%. Conversely, eel’s occurrence dropped only by ca. 44% in dam-free sites. During the historical period, eel’s occurrence was mostly affected by time since the initial habitat fragmentation, flow, distance to dams, connectivity, and dams’ height. In the most recent period, eel’s occurrence is mostly affected by dams’ building year, dam-to-sea distance, and, again, dams’ height. Results pinpoint that dams’ construction features and the time from their construction have significant negative effects on eel’s occurrence. Addition of future effective eel restoration practices, apart any other adverse environmental stressor, must consider dams’ removal, wherever socially sustainable or alternatively, the modification of construction features of dams (like excessive height) and the addition of fish ladders
Spring honey bee losses in Italy
Honey bee poisoning incidents and monitoring schemes Background: During last years several cases of bee losses have been reported during the period of corn sowing in different European countries. In Italy an institutional system for bee losses survey does not exist and therefore some Italian regions decided to organise an official network to collect data and analyse dead bee samples. Results: Collected data indicate that the higher number of bee losses events occurred in intensively cultivated flat areas, located in the North of Italy, mainly during or after corn sowing. The chemical analyses of dead bees revealed the presence of three neonicotinoid residues: imidacloprid was found in 25.7% of the sample, thiamethoxam in 2.8%, clothianidin in 25.7%, both imidacloprid and thiamethoxam in 4.7%. The visual examination and the virological analyses excluded pathological causes. Conclusion: The spatial and temporal correlation between hive damages and corn sowing and the presence of residues of active ingredients used for seed dressing (imidacloprid, thiamethoxam and clothianidin) in almost half of the samples confirms the connection between spring mortality and the sowing of corn seed dressed with neonicotinoids. Keywords: honeybee mortality, neonicotinoids, seed dressing, corn sowing, dust dispersion.     Â
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