Idealness of k-wise intersecting families.

A clutter is k-wise intersecting if every k members have a common element, yet no element belongs to all members. We conjecture that, for some integer k ≥ 4 , every k-wise intersecting clutter is non-ideal. As evidence for our conjecture, we prove it for k = 4 for the class of binary clutters. Two key ingredients for our proof are Jaeger's 8-flow theorem for graphs, and Seymour's characterization of the binary matroids with the sums of circuits property. As further evidence for our conjecture, we also note that it follows from an unpublished conjecture of Seymour from 1975. We also discuss connections to the chromatic number of a clutter, projective geometries over the two-element field, uniform cycle covers in graphs, and quarter-integral packings of value two in ideal clutters.

Effects of concurrent training on irisin and fibronectin type-III domain containing 5 (FNDC5) expression in visceral adipose tissue in type-2 diabetic rats.

CONTEXT: Evidence suggests that myokines could have clinical implications for metabolic diseases such as type-2 diabetes. OBJECTIVE: We investigated the effects of concurrent training (CT) on irisin and fibronectin type-III domain containing five (FNDC5) expressions in visceral adipose tissue (VAT) in type-2 diabetic rats. MATERIALS AND METHODS: Eighteen male Wistar rats (ages four to eight weeks) became diabetic using nicotinamide and streptozotocin and were assigned to either a control (CON) or a CT group using a randomised block design. The CT group exercised on a motor-driven treadmill at 60 to 75 per cent of VO2max (0% grade) for 10-40 min/day (aerobic training) and performed 10 climbs on a 1-meter ladder utilising weighted resistance of 30-100% of body mass (resistance exercise) for 5 days/week over 8 weeks. Forty-eight hours after the last training session, the VAT of rats was removed and washed. FNDC5-relative gene expression and irisin were measured by the reverse transcription polymerase chain reaction (RT-PCR) method and enzyme-linked immunosorbent assay (ELISA) kit. Additionally, insulin resistance and plasma insulin and glucose levels were determined. RESULTS: Our findings revealed that CT significantly increased FNDC5-relative gene expression in the VAT of type-2 diabetic rats compared to controls. Furthermore, eight weeks of CT improved insulin resistance and insulin and glucose levels but did not significantly alter irisin levels in type-2 diabetic rats. DISCUSSION AND CONCLUSION: The results of this study demonstrated that CT increased FNDC5 mRNA and improved insulin resistance, insulin, and glucose levels. Also observed were increased trends (non-significant, p = .051) in irisin levels. Hence, CT may play a role in attenuating metabolic disorders such as obesity and type-2 diabetes.

Dynamics of the nanoneedle probe in trolling mode AFM.

Atomic force microscopy (AFM), as an indispensable tool for nanoscale characterization, presents major drawbacks for operation in a liquid environment arising from the large hydrodynamic drag on the vibrating cantilever. The newly introduced 'Trolling mode' (TR-mode) AFM resolves this complication by using a specialized nanoneedle cantilever that keeps the cantilever outside of the liquid. Herein, a mechanical model with a lumped mass was developed to capture the dynamics of such a cantilever with a nanoneedle tip. This new developed model was applied to investigate the effects of the needle-liquid interface on the performance of the AFM, including the imaging capability in liquid.

Overgeneral autobiographical memory recollection in Iranian combat veterans with posttraumatic stress disorder.

This study examined the recollection of autobiographical material in memory among Iranian military veterans with and without posttraumatic stress disorder (PTSD), and healthy non-trauma-exposed control subjects. Participants completed the Autobiographical Memory Test, Autobiographical Memory Interview (counterbalanced), Impact of Event Scale-Revised, Beck Depression Inventory-II, Wechsler Memory Scale-III and Wechsler Adult Intelligence Scale-Revised. The PTSD group generated fewer specific episodic and semantic details of autobiographical memory compared to the non-PTSD and control groups. Working memory did not significantly moderate the relationship between PTSD diagnosis and reduced autobiographical memory specificity but did moderate the relationship between PTSD diagnosis and semantic recall; semantic memory recall was not significantly related to working memory ability for those with PTSD but was related to working memory ability for trauma survivors without PTSD. While the data provide some support for the expectation that higher working memory ability is associated with an increased ability to retrieve specific memories (i.e. semantic memory recall in those without PTSD), the findings are also consistent with the view that for those with PTSD the demands on working memory required for affect regulation cancel out this influence of working memory in augmenting access to specific memories.