Starobinsky-like two-field inflation

We consider an extension of the Starobinsky model, whose parameters are functions of an extra scalar field. Our motivation is to test the robustness (or sensitivity) of the Starobinsky inflation against mixing scalaron with another (matter) scalar field. We find that the extended Starobinsky model is (classically) equivalent to the two-field inflation, with the scalar potential having a flat direction. For the sake of fully explicit calculations, we perform a numerical scan of the parameter space. Our numerical calculations support the viability of the Starobinsky-like two-field inflation for the certain range of its parameters, which are characterized by the scalar index $n_s=0.96\pm 0.01$, the tensor-to-scalar ratio $r<0.06$, and small running of the scalar index at $|\alpha_s|<0.05$.Comment: 25 pages, 8 figures; LaTeX; minor revision: short comments and references added, most of Sec.3 moved to Appendi

Fourth-order gravity as the inflationary model revisited

We revisit the old (fourth-order or quadratically generated) gravity model of Starobinsky in four space-time dimensions, and derive the (inflaton) scalar potential in the equivalent scalar-tensor gravity model via a Legendre-Weyl transform. The inflaton scalar potential is used to compute the (CMB) observables of inflation associated with curvature perturbations (namely, the scalar and tensor spectral indices, and the tensor-to-scalar ratio), including the new next-to-leading-order terms with respect to the inverse number of e-foldings. The results are compared to the recent (WMAP5) experimental bounds. We confirm both mathematical and physical equivalence between f(R) gravity theories and the corresponding scalar-tensor gravity theories.Comment: 10 pages, 1 figure, 1 table, LaTeX; few comments added, style improved, references added and update

Slow-roll inflation in (R+R*4) gravity

We reconsider the toy-model of topological inflation, based on the R*4-modified gravity. By using its equivalence to the certain scalar-tensor gravity model in four space-time dimensions, we compute the inflaton scalar potential and investigate a possibility of inflation. We confirm the existence of the slow-roll inflation with an exit. However, the model suffers from the eta-problem that gives rise to the unacceptable value of the spectral index n_s of scalar perturbations.Comment: 12 pages, 3 figures, LaTeX, misprints corrected and references update

Effect of Devised Simultaneous Physical Function Improvement Training and Posture Learning Exercises on Posture

Poor posture in young adults and middle-aged people is associated with neck and back pain which are among the leading causes of disability worldwide. Training posture maintenance muscles and learning about ideal posture are important for improving poor posture. However, the effect of using both approaches simultaneously has not been verified, and it is unclear how long the effects persist after the intervention. Forty female university students were randomly and evenly assigned to four groups: physical function improvement training, posture learning, combination, and control groups. Four weeks of intervention training was conducted. Postural alignment parameters were obtained, including trunk anteroposterior inclination, pelvic anteroposterior inclination, and vertebral kyphosis angle. Physical function improvement training for improving crossed syndrome included two types of exercises: “wall-side squatting” and “wall-side stretching”. The posture learning intervention consisted of two types of interventions: “standing upright with their back against the wall” and “rolled towel”. A multiple comparison test was performed after analysis of covariance to evaluate the effect of each group’s postural change intervention on postural alignment. Only the combination group showed an effective improvement in all posture alignments. However, it was found that a week after the 4-week intervention, the subjects’ postures returned to their original state

Breast Cancer Brain Metastasis—Overview of Disease State, Treatment Options and Future Perspectives

Breast cancer is the second most common origin of brain metastasis after lung cancer. Brain metastasis in breast cancer is commonly found in patients with advanced course disease and has a poor prognosis because the blood–brain barrier is thought to be a major obstacle to the delivery of many drugs in the central nervous system. Therefore, local treatments including surgery, stereotactic radiation therapy, and whole-brain radiation therapy are currently considered the gold standard treatments. Meanwhile, new targeted therapies based on subtype have recently been developed. Some drugs can exceed the blood–brain barrier and enter the central nervous system. New technology for early detection and personalized medicine for metastasis are warranted. In this review, we summarize the historical overview of treatment with a focus on local treatment, the latest drug treatment strategies, and future perspectives using novel therapeutic agents for breast cancer patients with brain metastasis, including ongoing clinical trials