Declining Rotation Curve and Brown Dwarf MACHOs

If the Galactic rotation speed at the Solar circle is $\sim 200$ km s$^{-1}$ or smaller, which is supported by several recent studies, the rotation curve of the Galaxy could be declining in the outermost region. Motivated by this, we investigate the effect of such declining rotation curve on the estimate of the MACHO mass and the fractional contribution of the MACHOs to the Galactic dark halo. Using Hernquist and Plummer halo models instead of the standard halo model, we find that the MACHO mass could be significantly smaller than that for the standard halo case. In particular, there exists a certain set of halo parameters for which the MACHO mass is 0.1$M_\odot$ or less and at the same time the MACHO contribution to the total mass of the halo is almost 100 %. This result indicates that a halo which consists solely of brown dwarfs can be consistent with both of the observed microlensing properties and the constraints from the rotation curve, provided the outer rotation curve is indeed declining.Comment: 8 pages and 4 figures, accepted for publication in ApJ Letter

Kondo Effect in Fermi Systems with a Gap: A Renormalization Group Study

We present the results of a Wilson Renormalization Group study of the single-impurity Kondo and Anderson models in a system with a gap in the conduction electron spectrum. The behavior of the impurity susceptibility and the zero-frequency response function, $T>$ are discussed in the cases with and without particle-hole symmetry. In addition, for the asymmetric Anderson model the correlation functions, $<\vec S \cdot\vec \sigma (0)>$,$$, and$$ are computed.Comment: 10 pages, 10 figure

The emerging roles and therapeutic potential of cyclin-dependent kinase 11 (CDK11) in human cancer.

Overexpression and/or hyperactivation of cyclin-dependent kinases (CDKs) are common features of most cancer types. CDKs have been shown to play important roles in tumor cell proliferation and growth by controlling cell cycle, transcription, and RNA splicing. CDK4/6 inhibitor palbociclib has been recently approved by the FDA for the treatment of breast cancer. CDK11 is a serine/threonine protein kinase in the CDK family and recent studies have shown that CDK11 also plays critical roles in cancer cell growth and proliferation. A variety of genetic and epigenetic events may cause universal overexpression of CDK11 in human cancers. Inhibition of CDK11 has been shown to lead to cancer cell death and apoptosis. Significant evidence has suggested that CDK11 may be a novel and promising therapeutic target for the treatment of cancers. This review will focus on the emerging roles of CDK11 in human cancers, and provide a proof-of-principle for continued efforts toward targeting CDK11 for effective cancer treatment

A New Computer Approach to Mixed Feature Classification for Forestry Application

A new computer approach for mapping mixed forest features (i.e., classes, types) from computes classification maps is presented in both theory and application. This approach is particularly useful and applicable to forestry stand mapping, where small areas are required to be absorbed into the surrounding to form homogeneous stands, and where mixed stands contain mixed proportions of different species of trees. Previous studies involving LANDSAT data show that mixed pine-hardwood stands are often erroneously classified as either pine or hardwood. The present work utilizes a modification and an iterative application of a previously developed computer program called CLEAN . The program CLEAN was tested on binary (2 classes, labeled 0 or 1) classification images. The modification called GETMIX operates on a multi-class image and works on one prespecified class in any one application. In any iteration, small sets of pixels with labels other than the prespecified class are eliminated, while small sets of pixels of the prespecified class are retained and have their labels temporarily changed to a new unique class. This new iterative approach was tested on LANDSAT-1 data over Sam Houston National Forest, and proved to be successful in mapping those mixed softwood/hardwood stands which were unidentifiable previously. Also due to the cleaning effect of the program GETMIX, the spotty appearance on computer classification maps was smoothed, resulting in postprocessed maps that more closely resembled resource maps

Absence of evidence is not evidence of absence:On the limited use of regression discontinuity analysis in higher education

When higher education students are assessed multiple times, teachers need to consider how these assessments can be combined into a single pass or fail decision. A common question that arises is whether students should be allowed to take a resit. Previous research has found little to no clear learning benefits of resits and therefore suggested they might not be advantangeous as they are costly for both students and institutions. However, we conducted a simulation study that shows such a conclusion to be presumptuous. Absence of evidence is not evidence of absence; our results illustrate that if a resit effect were to exist, the analysis used in these studies (i.e. regression discontinuity analysis; RDA) lacked the power to detect such an effect. Power of RDA was only sufficient under extremely implausible conditions (i.e. large sample, large effect size, high correlation between examinations). To adequately compare the effect of assessment policies, researchers are recommended to use other methods than RDA

The Dutch version of the Behavior Rating Inventory of Executive Function-2 (BRIEF-2)

The BRIEF-2 (Gioia et al., 2015) is a widely used questionnaire to measure daily behavior related to executive function behaviors in the home and school environment of children between 5 and 18 years old. The current study was conducted to investigate the psychometric properties of the Dutch version of the BRIEF-2 in a representative Dutch-speaking norm sample. Using methods from classical test theory and network theory, we examined the reliability and validity of the BRIEF-2. The results indicated that the BRIEF-2 can be considered as a valid and reliable questionnaire that provides information on the role of executive function in the child’s and adolescent’s functioning in the home and school environment.</p