29 research outputs found
Fractal Scales in a Schwarzschild Atmosphere
Recently, Glass and Krisch have extended the Vaidya radiating metric to
include both a radiation fluid and a string fluid [1999 Class. Quantum Grav.
vol 16, 1175]. Mass diffusion in the extended Schwarzschild atmosphere was
studied. The continuous solutions of classical diffusive transport are believed
to describe the envelope of underlying fractal behavior. In this work we
examine the classical picture at scales on which fractal behavior might be
evident.Comment: to appear in Class. Quantum Gra
BRE modulates granulosa cell death to affect ovarian follicle development and atresia in the mouse
The BRE (brain and reproductive expression) gene, highly expressed in nervous and reproductive system organs, plays an important role in modulating DNA damage repair under stress response and pathological conditions. Folliculogenesis, a process that ovarian follicle develops into maturation, is closely associated with the interaction between somatic granulosa cell and oocyte. However, the regulatory role of BRE in follicular development remains undetermined. In this context, we found that BRE is normally expressed in the oocytes and granulosa cells from the primordial follicle stage. There was a reduction in follicles number of BRE mutant (BRE(−/−)) mice. It was attributed to increase the follicular atresia in ovaries, as a result of retarded follicular development. We established that cell proliferation was inhibited, while apoptosis was markedly increased in the granulosa cells in the absence of BRE. In addition, expressions of γ-H2AX (marker for showing DNA double-strand breaks) and DNA damage-relevant genes are both upregulated in BRE(−/−) mice. In sum, these results suggest that the absence of BRE, deficiency in DNA damage repair, causes increased apoptosis in granulosa cells, which in turn induces follicular atresia in BRE(−/−) mice
Cover Cropping and Conservation Tillage in California Processing Tomatoes
By using cover cropping and conservation tillage, processing tomato growers can reduce their costs and improve their soil at the same time, while still producing an economical crop
Conservation tillage systems for cotton advance in the San Joaquin Valley
Cotton production in the San Joaquin Valley has traditionally relied heavily on tillage for its presumed benefits to plant establishment, yields and insect management. Research in the 1960s and 1970s demonstrated the potential of precision or zone tillage, which foreshadowed the introduction of a variety of minimum tillage implements in the early 1990s. During a 3-year comparison study from 2001 to 2003, cotton yields in strip tillage plots matched or exceeded yields of standard tillage plots in all 3 years. In a 12-year study from 1999 to 2011, tillage costs were lowered an average of $70 per acre in 2011 dollars using no-tillage compared to standard tillage while achieving statistically comparable yields, provided that adequate crop stands were achieved. If bottom-line profitability can be maintained, conservation tillage may become increasingly attractive to cotton producers in the San Joaquin Valley
An Irreversible Constitutive Law for Modeling the Delamination Process Using Interface Elements
An irreversible constitutive law is postulated for the formulation of..