BATCH REVERSE OSMOSIS: EXPERIMENTAL RESULTS, MODEL VALIDATION, AND DESIGN IMPLICATIONS

In theory, batch reverse osmosis (RO) systems can achieve the lowest practical energy consumption by varying feed pressure over time. However, few batch RO syste ms have been built and operated. We have tested a bench-scale prototype of a true batch RO system using a bladder and a 2.5” (6.35 cm) spiral wound membrane element. Some practical issues in implementing batch RO include system start-up time, system depressurization, osmotic backwash during the reset phases, and lower permeate quality. This study is the first to validate batch models by measuring the hydraulic work of both the high pressure pump and the circulation pump. The experimental measurements agree well with the model (error ≤ 3 %) after accounting for concentration polarization. We used the validated model to calculate the energy savings of true batch systems at higher salinities and recovery ratios. We find that the energy savings achievable by true batch systems are less than previously thought, but still significant at relatively high recoveries. At 50% recovery of seawater feed, a batch RO plant could save 15% of the energy consumed by a continuous RO plant while still maintaining the same effective flux. Further studies should identify the additional costs associated with batch RO in order to identify the operating conditions where batch RO will be an economically favorable option compared to conventional continuous RO

Moderate-vigorous physical activity and health-related quality of life among Hispanic/Latino adults in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL).

BackgroundPhysical activity is a modifiable healthy behavior that has been shown to positively influence health-related quality of life. However, research examining the link between physical activity and health-related quality of life among Hispanic/Latino adults is limited and inconsistent. The purpose of this study is to assess whether accelerometer-measured moderate-vigorous physical activity (MVPA) is associated with self-reported (a) mental health-related quality of life, and (b) physical health-related quality of life among diverse Hispanic/Latino adults in the US.MethodsCross-sectional data from 12,379 adults ages 18-74 years in 2008-2011, who participated in HCHS/SOL and had complete data were analyzed using complex survey design methods. Accelerometer data were categorized into no MVPA, low, moderate, and high MVPA. Health-related quality of life was assessed with the Short-Form 12 and we used the mental and physical component subscales where higher scores indicate better health-related quality of life. Multivariate linear regression models were used to derive adjusted means with 95% confidence intervals and linear trends.ResultsWe observed no significant linear trend between accelerometer-measured MVPA and mental health-related quality of life (ptrend = 0.73). There was a significant positive association between MVPA and physical health-related quality of life (ptrend < 0.001) where higher MVPA corresponded with higher scores in physical health-related quality of life. The adjusted means were 46.67 (44.85-48.48) for no MVPA, 49.33 (49.03-49.63) for low MVPA, 50.61 (50.09-51.13) for moderate MVPA, and 51.36 (50.86-51.86) for high MVPA.ConclusionsAmong diverse Hispanic/Latino adults in the US, accelerometer-measured MVPA was associated with physical health-related quality of life, but not mental health-related quality of life. Future interventions should evaluate if increases in MVPA lead to improvements in health-related quality of life

The impact of histopathology and NAB2-STAT6 fusion subtype in classification and grading of meningeal solitary fibrous tumor/hemangiopericytoma.

Meningeal solitary fibrous tumor (SFT)/hemangiopericytoma (HPC) is a rare tumor with propensity for recurrence and metastasis. Although multiple classification schemes have been proposed, optimal risk stratification remains unclear, and the prognostic impact of fusion status is uncertain. We compared the 2016 WHO CNS tumor grading scheme (CNS-G), a three-tier system based on histopathologic phenotype and mitotic count, to the 2013 WHO soft-tissue counterpart (ST-G), a two-tier system based on mitotic count alone, in a cohort of 133 patients [59 female, 74 male; mean age 54 years (range 20-87)] with meningeal SFT/HPC. Tumors were pathologically confirmed through review of the first tumor resection (n = 97), local recurrence (n = 35), or distant metastasis (n = 1). A STAT6 immunostain showed nuclear expression in 132 cases. NAB2-STAT6 fusion was detected in 99 of 111 successfully tested tumors (89%) including the single STAT6 immunonegative tumor. Tumors were classified by CNS-G as grade 1 (n = 43), 2 (n = 41), or 3 (n = 49), and by ST-G as SFT (n = 84) or malignant SFT (n = 49). Necrosis was present in 16 cases (12%). On follow-up, 42 patients had at least one subsequent recurrence or metastasis (7 metastasis only, 33 recurrence only, 2 patients had both). Twenty-nine patients died. On univariate analysis, necrosis (p = 0.002), CNS-G (p = 0.01), and ST-G (p = 0.004) were associated with recurrence-free (RFS) but not overall survival (OS). NAB2-STAT6 fusion type was not significantly associated with RFS or OS, but was associated with phenotype. A modified ST-G incorporating necrosis showed higher correlation with RFS (p = 0.0006) and remained significant (p = 0.02) when considering only the primary tumors. From our data, mitotic rate and necrosis appear to stratify this family of tumors most accurately and could be incorporated in a future grading scheme

Bergmann Glia and the Recognition Molecule CHL1 Organize GABAergic Axons and Direct Innervation of Purkinje Cell Dendrites

The geometric and subcellular organization of axon arbors distributes and regulates electrical signaling in neurons and networks, but the underlying mechanisms have remained elusive. In rodent cerebellar cortex, stellate interneurons elaborate characteristic axon arbors that selectively innervate Purkinje cell dendrites and likely regulate dendritic integration. We used GFP BAC transgenic reporter mice to examine the cellular processes and molecular mechanisms underlying the development of stellate cell axons and their innervation pattern. We show that stellate axons are organized and guided towards Purkinje cell dendrites by an intermediate scaffold of Bergmann glial (BG) fibers. The L1 family immunoglobulin protein Close Homologue of L1 (CHL1) is localized to apical BG fibers and stellate cells during the development of stellate axon arbors. In the absence of CHL1, stellate axons deviate from BG fibers and show aberrant branching and orientation. Furthermore, synapse formation between aberrant stellate axons and Purkinje dendrites is reduced and cannot be maintained, leading to progressive atrophy of axon terminals. These results establish BG fibers as a guiding scaffold and CHL1 a molecular signal in the organization of stellate axon arbors and in directing their dendritic innervation