A Remark on Lorentz Violation at Finite Temperature

We investigate the radiatively induced Chern-Simons-like term in four-dimensional field theory at finite temperature. The Chern-Simons-like term is temperature dependent and breaks the Lorentz and CPT symmetries. We find that this term remains undetermined although it can be found unambiguously in different regularization schemes at finite temperature.Comment: To appear in JHEP, 8 pages, 1 eps figure, minor changes and references adde

Lorentz-CPT violation, radiative corrections and finite temperature

In this work we investigate the radiatively induced Chern-Simons-like terms in four-dimensions at zero and finite temperature. We use the approach of rationalizing the fermion propagator up to the leading order in the CPT-violating coupling $b_\mu$. In this approach, we have shown that although the coefficient of Chern-Simons term can be found unambiguously in different regularization schemes at zero or finite temperature, it remains undetermined. We observe a correspondence among results obtained at finite and zero temperature.Comment: To appear in JHEP, 10 pages, 1 eps figure, minor changes and references adde

Phytohemagglutinin improves the development and ultrastructure of in vitro-cultured goat (Capra hircus) preantral follicles

The objective this study was to determine the effect of phytohemagglutinin (PHA) on survival, growth and gene expression in caprine secondary follicles cultured in vitro. Secondary follicles (&#8764;0.2&#8197;mm) were isolated from the cortex of caprine ovaries and cultured individually for 6 days in &#945;-MEM+ supplemented with PHA (0, 1, 10, 50, 100, or 200&#8197;&#181;g/mL). After 6 days of culture, follicle diameter and survival, antrum formation, ultrastructure and expression of mRNA for FSH receptors (FSH-R), proliferating cell nuclear antigen (PCNA), and neuronal nitric oxide synthase were determined. All treatments maintained follicular survival [&#945;-MEM+ (94.59%); 1&#8197;&#181;g/mL PHA (96.43%); 10&#8197;&#181;g/mL PHA (84.85%); 50&#8197;&#181;g/mL PHA (85.29%); 100&#8197;&#181;g/mL PHA (88.57%), and 200&#8197;&#181;g/mL PHA (87.50)], but the presence of 10&#8197;&#181;g/mL PHA in the culture medium increased the antrum formation rate (21.21%) when compared with control (5.41%, P < 0.05) and ensured the maintenance of oocyte and granulosa cell ultrastructures after 6 days of culture. The expression of mRNA for FSH-R (2.7 &#177; 0.1) and PCNA (4.4 &#177; 0.2) was also significantly increased in follicles cultured with 10&#8197;&#181;g/mL PHA in relation to those cultured in &#945;-MEM+ (1.0 &#177; 0.1). In conclusion, supplementation of culture medium with 10&#8197;&#181;g/mL PHA maintains the follicular viability and ultrastructure, and promotes the formation of antral cavity after 6 days of culture in vitro