A
bstract
We construct a noncommutative kappa-Minkowski deformation of U(1) gauge theory, following a general approach, recently proposed in JHEP 08 (2020) 041. We obtain an exact (all orders in the ...non-commutativity parameter) expression for both the deformed gauge transformations and the deformed field strength, which is covariant under these transformations. The corresponding Yang-Mills Lagrangian is gauge covariant and reproduces the Maxwell Lagrangian in the commutative limit. Gauge invariance of the action functional requires a non-trivial integration measure which, in the commutative limit, does not reduce to the trivial one. We discuss the physical meaning of such a nontrivial commutative limit, relating it to a nontrivial space-time curvature of the undeformed theory. Moreover, we propose a rescaled kappa-Minkowski noncommutative structure, which exhibits a standard flat commutative limit.
A
bstract
We consider gauge theories on Poisson manifolds emerging as semiclassical approximations of noncommutative spacetime with Lie algebra type noncommutativity. We prove an important identity, ...which allows to obtain simple and manifestly gauge-covariant expressions for the Euler-Lagrange equations of motion, the Bianchi and the Noether identities. We discuss the non-Lagrangian equations of motion, and apply our findings to the
κ
-Minkowski case. We construct a family of exact solutions of the deformed Maxwell equations in the vacuum. In the classical limit, these solutions recover plane waves with left-handed and right-handed circular polarization, being classical counterparts of photons. The deformed dispersion relation appears to be nontrivial.
Poisson gauge models and Seiberg-Witten map Kupriyanov, V. G.; Kurkov, M. A.; Vitale, P.
The journal of high energy physics,
11/2022, Volume:
2022, Issue:
11
Journal Article
Peer reviewed
Open access
A
bstract
The semiclassical limit of full non-commutative gauge theory is known as Poisson gauge theory. In this work we revise the construction of Poisson gauge theory paying attention to the ...geometric meaning of the structures involved and advance in the direction of a further development of the proposed formalism, including the derivation of Noether identities and conservation of currents. For any linear non-commutativity, Θ
ab
(
x
) =
f
c
ab
x
c
, with
f
c
ab
being structure constants of a Lie algebra, an explicit form of the gauge Lagrangian is proposed. In particular a universal solution for the matrix
ρ
defining the field strength and the covariant derivative is found. The previously known examples of
κ
-Minkowski,
λ
-Minkowski and rotationally invariant non-commutativity are recovered from the general formula. The arbitrariness in the construction of Poisson gauge models is addressed in terms of Seiberg-Witten maps, i.e., invertible field redefinitions mapping gauge orbits onto gauge orbits.
Since cyclooxygenase (COX) isozymes discovery, many papers and reviews have been published to describe the structural bases of COX inhibition, and to debate on the therapeutic and adverse effects of ...worldwide clinically used nonsteroidal anti-inflammatory drugs (NSAIDs), included COX-2 selective inhibitors (well known as Coxibs). COX-2 inhibition has been widely investigated, whereas the role of COX-1 in human pathophysiology is mostly not yet well ascertained. As time goes on, the cliché that the constitutively expressed isoform COX-1 is only involved in normal physiological functions, such as platelet aggregation, gastric mucosa protection and renal electrolyte homeostasis is going to be shattered. Low-dose aspirin, behaving as a preferential inhibitor of platelet COX-1, allowed to enlighten the role exerted by this isoenzyme in many mammalian cell types. This review would elucidate the most recent findings on selective COX-1 inhibition and their relevance to human pathology such as cancer, neuro-inflammation, cardioprotection, fever and pain. It would also focus on the design and development of new highly selective COX-1 inhibitors, useful tools in pharmacological studies aimed at gaining a deeper insight of the role of COX-1 in human health and disease. Among the traditional NSAIDs, other then aspirin and indomethacin, only few examples of selective COX-1 inhibitors (SC-560, FR122047, mofezolac, P6 and TFAP) have been so far identified. This review has also the scope to stimulate the development of novel drugs, which activity is COX-1 mediated.
Technical efficiency (TE) is an important measure of farm performance. This study measured the TE of wheat farms across six states in the U.S. Western Great Plains based on production and farm ...management-specific variables. Significant factors positively influencing efficiency were insecticide use, farm size, and tillage. Alternatively, government payments, crop insurance, off-farm income, and crop share rates had negative effects on efficiency. Kansas and Oklahoma farms were more efficient than Nebraska and Wyoming farms in the sample. Average TE score of 0.56 indicates a substantial gap between average producers and the most efficient ones located near the TE frontier. Benchmarking the highly efficient farms provides best-management practices enabling less-efficient farms move closer to the efficient frontier. Extension specialists and collaboration among farms could transfer the skills and techniques through workshops, webinars, fact sheets, and social media pages.
Amphiphilic copolymers have a wide variety of medical and biotechnological applications, including DNA transfection in eukaryotic cells. Still, no polymer-primed transfection of prokaryotic cells has ...been described. The reversible addition-fragmentation chain transfer (RAFT) polymer synthesis technique and the reversible deactivation radical polymerization variants allow the design of polymers with well-controlled molar mass, morphology, and hydrophilicity/hydrophobicity ratios. RAFT was used to synthesize two amphiphilic copolymers containing different ratios of the amphiphilic poly2-(dimethyl-amino) ethyl methacrylate and the hydrophobic poly methyl methacrylate. These copolymers bound to pUC-19 DNA and successfully transfected non-competent Escherichia coli DH5α, with transformation efficiency in the range of 103 colony-forming units per µg of plasmid DNA. These results demonstrate prokaryote transformation using polymers with controlled amphiphilic/hydrophobic ratios.
STUDY QUESTION
What is the impact of smoking behaviour on seminal, hormonal and male genital tract ultrasound parameters in subjects seeking medical care for couple infertility?
STUDY ANSWER
In males ...of infertile couples, current smokers (CS), when compared with non-smokers, show lower ejaculate and ultrasound-derived seminal vesicles (SV) volume, despite higher testosterone levels.
WHAT IS KNOWN ALREADY
Data on the effects of smoking on male fertility are conflicting. A correlation between smoking and reduced semen parameters has been reported, however, with a high heterogeneity among studies. An association between smoking behaviour and higher testosterone levels in men has been described in several, but not all, the previous studies. No study has systematically evaluated the impact of smoking on the male genital tract ultrasound characteristics.
STUDY DESIGN, SIZE AND DURATION
Retrospective cross-sectional analysis of a consecutive series of 426 subjects seeking medical care for couple infertility from January 2010 to July 2013.
PARTICIPANTS/MATERIALS, SETTING, METHODS
From the entire cohort, 394 men (age 36.0 ± 8.0 years) free of genetic abnormalities were selected. All subjects underwent a complete andrological and physical examination, biochemical and hormonal assessment, scrotal and transrectal colour-Doppler ultrasound and semen analysis (including seminal interleukin-8 levels, sIL-8) within the same day.
MAIN RESULTS AND THE ROLE OF CHANCE
Among the patients evaluated, 229 were never smokers (NS), 56 past smokers (PS) and 109 CS. When CS were compared with the rest of the sample (non-smokers, NS + PS), in a multivariate model (analysis of covariance, ANCOVA) adjusted for age, lifestyle (including alcohol, cannabis and physical activity), BMI and sex hormone-binding globulin, significantly higher androgen (total testosterone, P = 0.001; calculated free testosterone, P < 0.005) and lower FSH (P < 0.05) levels were observed in CS. However, when total testosterone was also included in the multivariate model as a further covariate, the difference in FSH levels was not confirmed. In a similar model, a lower ejaculate volume (P < 0.01) and a higher prevalence of normal sperm morphology (P < 0.02) were also detected in CS in comparison with the rest of the sample. However, when total testosterone was also included in the multivariate model as a further covariate, only the difference in ejaculate volume between CS and non-smokers was confirmed (−0.61 ± 0.23 ml, P < 0.01). Finally, CS showed lower total SV volume, before and after ejaculation, even after adjusting for confounders (P = 0.02 and <0.01, respectively). Similar results were observed when the reported number of cigarettes smoked or the number of pack-years was considered separately.
LIMITATIONS, REASONS FOR CAUTION
The present results are derived from patients consulting an Andrology Clinic for couple infertility, who could have different characteristics from the general male population or males consulting general practitioners for reasons other than couple infertility. In addition, we did not have a true control group composed of age-matched, apparently healthy, fertile men, and therefore true normative data of sonographic parameters cannot be inferred. Due to the cross-sectional nature of our study, neither a causality hypothesis nor mechanistic models can be drawn. Finally, this is a retrospective study, and further prospective studies are required.
WIDER IMPLICATIONS OF THE FINDINGS
We report an apparent paradox in CS: lower SV volume despite higher testosterone levels. Our data suggest that smoking may negatively affect SV volume in an independent manner, as the difference between CS and non-smokers retained significance after adjusting for confounders including testosterone. This is the first study reporting such ultrasound evidence. How this new smoking-related alteration, along with low semen volume, impacts male fertility needs to be addressed by further studies.
STUDY FUNDING/COMPETING INTEREST(S)
No funding was received for the study. None of the authors have any conflict of interest to declare.
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