Conventionally, evolution has always been described in terms of species. The Chemistry of Evolution takes a novel, not to say revolutionary, approach and examines the evolution of chemicals and the ...use and degradation of energy, coupled to the environment, as the drive behind it. The authors address the major changes of life from bacteria to man in a systematic and unavoidable sequence, reclassifying organisms as chemotypes. Written by the authors of the bestseller The Biological Chemistry of the Elements - The Inorganic Chemistry of Life (Oxford University Press, 1991), the clarity and precision of The Chemistry of Evolution plainly demonstrate that life is totally interactive with the environment. This exciting theory makes this work an essential addition to the academic and public library.* Provides a novel analysis of evolution in chemical terms * Stresses Systems Biology * Examines the connection between life and the environment, starting with the 'big bang' theory * Reorientates the chemistry of life by emphasising the need to analyse the functions of 20 chemical elements in all organisms
Low density sugarcane plantation (LDSP) has been implemented by some sugarcane producers in Brazil, aiming to save seeds and operational costs. The study was carried out in the municipality of Areia, ...Paraíba, Brazil. Five planting densities were used, varying from 5 to 25 m-2 of buds arranged in randomized blocks, with four replications. Data were measured annually over three cultivation cycles (2017 to 2020), during which the field was fertilized with NPK and the harvests were carried out manually without prior burning. The lower planting density presents higher productivity only in the cane plant (101.03 t ha-1) due to the higher plant height (2.37 m) and the higher number of stalks (11 stalks m-2), suggesting that these variables are due to the greater availability of light, water and photosynthate. However, there is a drastic reduction in sugarcane yield for this lower population in the 2nd ratoon by up to 65.62%, which is correlated with number of stalks per meter. We demonstrate the agronomic viability of LDSP in the population of 10 buds m-2 in relation to conventional planting of sugarcane until the 2nd ratoon. Data are important for future studies to present additional considerations for other production factors, such as the effects of mechanized harvesting and the management of nutrients and water, assessing the sustainability of this large-scale planting system.
Planting with higher density in sugarcane is one of the practices used to overcome low productivity. However, this planting material is equivalent to 25% of the total cost of production, being one of ...the main expenses for cultivation. In this sense, the present work aims to evaluate the productivity and economic viability of sugarcane as a function of planting density. The experiment was carried out at Usina Monte Alegre in the municipality of Mamanguape, Paraíba, Brazil, from March 2021 to January 2022 with the variety RB92579. Seven planting density were studied: T1: 7 gems m-1, T2: 10 gems m-1, T3: 12 gems m-1, T4: 11 gems m-1, T5: 15 gems m-1, T6: 17 gems m-1, T7: 24 gems m-1, in randomized blocks with four replications. Growth, productivity and economic viability were evaluated. The highest productivity of cane and sugar, 77.69 ton ha-1 and 10.390 ton ha-1, respectively, was with planting density of 17 and 24 gems-1. While the minimum productivity of cane (61.313 ton ha-1) and sugar (7.924 ton ha-1) was recorded at sowing density of 7 and 11 gems-1. However, cultivation density with 7 and 10 gems m-1 were the ones that provided the highest profitability around 50%, followed by density of 12, 15 and 17 gems m-1 with an average of 45% profit and 11 and 24 gems m-1 with the lowest proportion of profit on average 38%. The cultivation with 17 gems m-1 of cane provides in cane-plant, variety RB92579, greater productivity with a profit rate of 45%, being the most suitable.
Quantiles via moments Machado, José A.F.; Santos Silva, J.M.C.
Journal of econometrics,
11/2019, Letnik:
213, Številka:
1
Journal Article
Recenzirano
Odprti dostop
We study the conditions under which it is possible to estimate regression quantiles by estimating conditional means. The advantage of this approach is that it allows the use of methods that are only ...valid in the estimation of conditional means, while still providing information on how the regressors affect the entire conditional distribution. The methods we propose are not meant to replace the well-established quantile regression estimator, but provide an additional tool that can allow the estimation of regression quantiles in settings where otherwise that would be difficult or even impossible. We consider two settings in which our approach can be particularly useful: panel data models with individual effects and models with endogenous explanatory variables. Besides presenting the estimator and establishing the regularity conditions needed for valid inference, we perform a small simulation experiment, present two simple illustrative applications, and discuss possible extensions.
Objective
In current management paradigms of rheumatoid arthritis (RA), patient global assessment (PGA) is crucial to decide whether a patient has attained remission (target) or needs reinforced ...therapy. We investigated whether the clinical and psychological determinants of PGA are appropriate to support this important role.
Methods
This was a cross‐sectional, single‐center study including consecutive ambulatory RA patients. Data collection comprised swollen 28‐joint count (SJC28), tender 28‐joint count (TJC28), C‐reactive protein (CRP) level, PGA, pain, fatigue, function, anxiety, depression, happiness, personality traits, and comorbidities. Remission was categorized using American College of Rheumatology/European League Against Rheumatism Boolean‐based criteria: remission, near‐remission (only PGA >1), and nonremission. A binary definition without PGA (3v‐remission) was also studied. Univariable and multivariable analyses were used to identify explanatory variables of PGA in each remission state.
Results
A total of 309 patients were included (remission 9.4%, near‐remission 37.2%, and nonremission 53.4%). Patients in near‐remission were indistinguishable from remission regarding disease activity, but described a disease impact similar to those in nonremission. In multivariable analyses, PGA in near‐remission was explained (R2adjusted = 0.50) by fatigue, pain, anxiety, and function. Fatigue and pain had no relationship with disease activity measures.
Conclusion
In RA, a consensually acceptable level of disease activity (SJC28, TJC28, and CRP level ≤1) does not equate to low disease impact: a large proportion of these patients are considered in nonremission solely due to PGA. PGA mainly reflects fatigue, pain, function, and psychological domains, which are inadequate to define the target for immunosuppressive therapy. This consideration suggests that clinical practice should be guided by 2 separate remission targets: inflammation (3v‐remission) and disease impact.
Prime editing (PE) is a powerful genome engineering approach that enables the introduction of base substitutions, insertions and deletions into any given genomic locus. However, the efficiency of PE ...varies widely and depends not only on the genomic region targeted, but also on the genetic background of the edited cell. Here, to determine which cellular factors affect PE efficiency, we carry out a focused genetic screen targeting 32 DNA repair factors, spanning all reported repair pathways. We show that, depending on cell line and type of edit, ablation of mismatch repair (MMR) affords a 2-17 fold increase in PE efficiency, across several human cell lines, types of edits and genomic loci. The accumulation of the key MMR factors MLH1 and MSH2 at PE sites argues for direct involvement of MMR in PE control. Our results shed new light on the mechanism of PE and suggest how its efficiency might be optimised.
Agricultural soil erosion is thought to perturb the global carbon cycle, but estimates of its effect range from a source of 1 petagram per year⁻¹ to a sink of the same magnitude. By using caesium-137 ...and carbon inventory measurements from a large-scale survey, we found consistent evidence for an erosion-induced sink of atmospheric carbon equivalent to approximately 26% of the carbon transported by erosion. Based on this relationship, we estimated a global carbon sink of 0.12 (range 0.06 to 0.27) petagrams of carbon per year⁻¹ resulting from erosion in the world's agricultural landscapes. Our analysis directly challenges the view that agricultural erosion represents an important source or sink for atmospheric CO₂.
In this Letter, we study the structural and electronic properties of single-layer and bilayer phosphorene with graphene. We show that both the properties of graphene and phosphorene are preserved in ...the composed heterostructure. We also show that via the application of a perpendicular electric field, it is possible to tune the position of the band structure of phosphorene with respect to that of graphene. This leads to control of the Schottky barrier height and doping of phosphorene, which are important features in the design of new devices based on van der Waals heterostructures.
Fernando de Noronha is an archipelago of 21 islands and islets in the Atlantic Ocean, state of Pernambuco, Brazil, which has a varied biodiversity including alien species or sinantropic animals. The ...objective here was to determine the seroprevalence of Toxoplasma gondii in domestic and wild animals from Fernando de Noronha archipelago, Brazil. Between July 2007 and May 2010, blood samples were collected from 764 animals (533 domestic and 231 wild animals). Sera were tested by the indirect fluorescence antibody test (IFAT) or the modified agglutination test (MAT), or by both. Antibodies to T. gondii were found in 80 (80.0%) of 100 chickens (Gallus domesticus), 3 (3.0%) of 100 cattle (Bos taurus), 59 (60.8%) of 97 sheep (Ovis aries), 9 (81.8%) of 11 goats (Capra hircus), 7 (43.7%) of 16 horses (Equus caballus), 70 (59.3%) of 118 cats (Felis catus), 36 (39.6%) of 91 dogs (Canis familiaris), 13 (38.2%) of 34 black rats (Rattus rattus), and 157 (79.7%) of 197 cattle egrets (Bubulcus ibis). Results indicate endemic infection by this zoonotic parasite among the animal and avian fauna in this archipelago from Brazil.
Vibrio cholerae can switch between motile and biofilm lifestyles. The last decades have been marked by a remarkable increase in our knowledge of the structure, regulation, and function of biofilms ...formed under laboratory conditions. Evidence has grown suggesting that V. cholerae can form biofilm-like aggregates during infection that could play a critical role in pathogenesis and disease transmission. However, the structure and regulation of biofilms formed during infection, as well as their role in intestinal colonization and virulence, remains poorly understood. Here, we review (i) the evidence for biofilm formation during infection, (ii) the coordinate regulation of biofilm and virulence gene expression, and (iii) the host signals that favor V. cholerae transitions between alternative lifestyles during intestinal colonization, and (iv) we discuss a model for the role of V. cholerae biofilms in pathogenicity.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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