An interdomain sector mediating allostery in Hsp70 molecular chaperones

The Hsp70 family of molecular chaperones provides a well defined and experimentally powerful model system for understanding allosteric coupling between different protein domains.New extensions to the statistical coupling analysis (SCA) method permit identification of a group of co-evolving amino-acid positions—a sector—in the Hsp70 that is associated with allosteric function.Literature-based and new experimental studies support the notion that the protein sector identified through SCA underlies the allosteric mechanism of Hsp70.This work extends the concept of protein sectors by showing that two non-homologous protein domains can share a single sector when the underlying biological function is defined by the coupled activity of the two domains

In vitro rooting of regenerants of blue poplar

The article presents the research results of the influence of hormonal composition of the culture medium and cultivation duration on regenerants of Populus pruinosa at the stage of rooting in vitro. 98,3±1,7 % of regenerants rooted on MS culture medium with 1,0 mg L−1 IMА during 8 weeks of cultivation.Приведены результаты исследований влияния гормонального состава питательной среды и длительности культивирования на растения-регенеранты тополя сизолистного на этапе укоренения in vitro; 98,3±1,7 % регенерантов укоренялись на питательной среде МС, дополненной 1,0 мг/л ИМК, в течение 8 недель культивирования

Improved Functional Outcome After Peripheral Nerve Stimulation of the Impaired Forelimb Post-stroke

Lack of blood flow to the brain, i.e., ischemic stroke, results in loss of nerve cells and therefore loss of function in the effected brain regions. There is no effective treatment to improve lost function except restoring blood flow within the first several hours. Rehabilitation strategies are widely used with limited success. The purpose of this study was to examine the effect of electrical stimulation on the impaired upper extremity to improve functional recovery after stroke. We developed a rodent model using an electrode cuff implant onto a single peripheral nerve (median nerve) of the paretic forelimb and applied daily electrical stimulation. The skilled forelimb reaching test was used to evaluate functional outcome after stroke and electrical stimulation. Anterograde axonal tracing from layer V pyramidal neurons with biotinylated dextran amine was done to evaluate the formation of new neuronal connections from the contralesional cortex to the deafferented spinal cord. Rats receiving electrical stimulation on the median nerve showed significant improvement in the skilled forelimb reaching test in comparison with stroke only and stroke with sham stimulation. Rats that received electrical stimulation also exhibited significant improvement in the latency to initiate adhesive removal from the impaired forelimb, indicating better sensory recovery. Furthermore, axonal tracing analysis showed a significant higher midline fiber crossing index in the cervical spinal cord of rats receiving electrical stimulation. Our results indicate that direct peripheral nerve stimulation leads to improved sensorimotor recovery in the stroke-impaired forelimb, and may be a useful approach to improve post-stroke deficits in human patients

Comparison of structural MRI brain measures between 1.5 and 3T: Data from the Lothian Birth Cohort 1936

Multi‐scanner MRI studies are reliant on understanding the apparent differences in imaging measures between different scanners. We provide a comprehensive analysis of T(1)‐weighted and diffusion MRI (dMRI) structural brain measures between a 1.5 T GE Signa Horizon HDx and a 3 T Siemens Magnetom Prisma using 91 community‐dwelling older participants (aged 82 years). Although we found considerable differences in absolute measurements (global tissue volumes were measured as ~6–11% higher and fractional anisotropy [FA] was 33% higher at 3 T than at 1.5 T), between‐scanner consistency was good to excellent for global volumetric and dMRI measures (intraclass correlation coefficient [ICC] range: .612–.993) and fair to good for 68 cortical regions (FreeSurfer) and cortical surface measures (mean ICC: .504–.763). Between‐scanner consistency was fair for dMRI measures of 12 major white matter tracts (mean ICC: .475–.564), and the general factors of these tracts provided excellent consistency (ICC ≥ .769). Whole‐brain structural networks provided good to excellent consistency for global metrics (ICC ≥ .612). Although consistency was poor for individual network connections (mean ICCs: .275−.280), this was driven by a large difference in network sparsity (.599 vs. .334), and consistency was improved when comparing only the connections present in every participant (mean ICCs: .533–.647). Regression‐based k‐fold cross‐validation showed that, particularly for global volumes, between‐scanner differences could be largely eliminated (R (2) range .615–.991). We conclude that low granularity measures of brain structure can be reliably matched between the scanners tested, but caution is warranted when combining high granularity information from different scanners

The ethics of characterizing difference: guiding principles on using racial categories in human genetics

We are a multidisciplinary group of Stanford faculty who propose ten principles to guide the use of racial and ethnic categories when characterizing group differences in research into human genetic variation