Preferential flow pathways in a deforming granular material: self-organization into functional groups for optimized global transport

Existing definitions of where and why preferential flow in porous media occurs, or will occur, assume a priori knowledge of the fluid flow and do not fully account for the connectivity of available flow paths in the system. Here we propose a method for identifying preferential pathways through a flow network, given its topology and finite link capacities. Using data from a deforming granular medium, we show that the preferential pathways form a set of percolating pathways that is optimized for global transport of interstitial pore fluid in alignment with the applied pressure gradient. Two functional subgroups emerge. The primary subgroup comprises the main arterial paths that transmit the greatest flow through shortest possible routes. The secondary subgroup comprises inter- and intra-connecting bridges that connect the primary paths, provide alternative flow routes, and distribute flow through the system to maximize throughput. We examine the multiscale relationship between functionality and subgroup structure as the sample dilates in the lead up to the failure regime where the global volume then remains constant. Preferential flow pathways chain together large, well-connected pores, reminiscent of force chain structures that transmit the majority of the load in the solid grain phase.

Finite groups with σ-Frobenius condition for non-normal σ-primary subgroups

Let [Formula: see text] be a partition of the set [Formula: see text] of all primes and [Formula: see text] a finite group. A group is said to be [Formula: see text]-primary if it is a finite [Formula: see text]-group for some [Formula: see text]. We say that a [Formula: see text]-subgroup [Formula: see text] of [Formula: see text] satisfies the [Formula: see text]-Frobenius condition in [Formula: see text] if [Formula: see text] is a [Formula: see text]-group. In this paper, we determine the structure of finite groups in which every non-normal [Formula: see text]-primary subgroup satisfies the [Formula: see text]-Frobenius condition.

Everolimus in Neuroendocrine Tumors of the Gastrointestinal Tract and Unknown Primary

Purpose: The RADIANT-4 randomized phase 3 study demonstrated significant prolongation of median progression-free survival (PFS) with everolimus compared to placebo (11.0 [95% CI 9.2-13.3] vs. 3.9 [95% CI 3.6-7.4] months) in patients with advanced, progressive, nonfunctional gastrointestinal (GI) and lung neuroendocrine tumors (NET). This analysis specifically evaluated NET patients with GI and unknown primary origin. Methods: Patients in the RADIANT-4 trial were randomized 2:1 to everolimus 10 mg/day or placebo. The effect of everolimus on PFS was evaluated in patients with NET of the GI tract or unknown primary site. Results: Of the 302 patients enrolled, 175 had GI NET (everolimus, 118; placebo, 57) and 36 had unknown primary (everolimus, 23; placebo, 13). In the GI subset, the median PFS by central review was 13.1 months (95% CI 9.2-17.3) in the everolimus arm versus 5.4 months (95% CI 3.6-9.3) in the placebo arm; the hazard ratio (HR) was 0.56 (95% CI 0.37-0.84). In the unknown primary patients, the median PFS was 13.6 months (95% CI 4.1-not evaluable) for everolimus versus 7.5 months (95% CI 1.9-18.5) for placebo; the HR was 0.60 (95% CI 0.24-1.51). Everolimus efficacy was also demonstrated in both midgut and non-midgut populations; a 40-46% reduction in the risk of progression or death was reported for patients in the combined GI and unknown primary subgroup. Everolimus had a benefit regardless of prior somatostatin analog therapy. Conclusions: Everolimus showed a clinically meaningful PFS benefit in patients with advanced progressive nonfunctional NET of GI and unknown primary, consistent with the overall RADIANT-4 results, providing an effective new standard treatment option in this patient population and filling an unmet treatment need for these patients.

Occurrence of the European Subgroup of Subtype I BK Polyomavirus in Japanese-Americans Suggests Transmission outside the Family

ABSTRACT To examine the mode of transmission of BK polyomavirus (BKV), urine samples were collected from Japanese-Americans in Los Angeles and from other southern Californians. Subtype I was the main subtype found in samples from both groups. The subtype I subgroup Ib-2, which is predominant in Europe, was the primary subgroup detected in second-generation Japanese-Americans and in southern Californians; however, the Ic subgroup prevalent in native Japanese was rare in these populations. Since the European subgroup (Ib-2) predominated in the studied geographic area, the findings demonstrate that transmission outside the family is common in the spread of BKV, unlike previous findings for JC polyomavirus.

GEOMETRIC REALIZATION AND K-THEORETIC DECOMPOSITION OF C*-ALGEBRAS

Suppose that A is a separable C*-algebra and that G* is a (graded) subgroup of the ℤ/2-graded group K*(A). Then there is a natural short exact sequence [Formula: see text] In this note we demonstrate how to geometrically realize this sequence at the level of C*-algebras. We KK-theoretically decompose A as [Formula: see text] where K*(At) is the torsion subgroup of K*(A) and K*(Af) is its torsionfree quotient. Then we further decompose At: it is KK-equivalent to ⊕p Ap where K*(Ap) is the p-primary subgroup of the torsion subgroup of K*(A). We then apply this realization to study the Kasparov group K*(A) and related objects.