Spatial mode detection by frequency upconversion

The efficient creation and detection of spatial modes of light has become topical of late, driven by the need to increase photon-bit-rates in classical and quantum communications. Such mode creation/detection is traditionally achieved with tools based on linear optics. Here we put forward a new spatial mode detection technique based on the nonlinear optical process of sum-frequency generation. We outline the concept theoretically and demonstrate it experimentally with intense laser beams carrying orbital angular momentum and Hermite-Gaussian modes. Finally, we show that the method can be used to transfer an image from the infrared band to the visible, which implies the efficient conversion of many spatial modes.Comment: Published version, 4 pages, 5 figure

Altimetry-Based Diagnosis of Deep-Reaching Sub-Mesoscale Ocean Fronts

Recent studies demonstrate that energetic sub-mesoscale fronts (10–50 km width) extend in the ocean interior, driving large vertical velocities and associated fluxes. However, diagnosing the dynamics of these deep-reaching fronts from in situ observations remains challenging because of the lack of information on the 3-D structure of the horizontal velocity. Here, a realistic numerical simulation in the Antarctic Circumpolar Current (ACC) is used to study the dynamics of submesocale fronts in relation to velocity gradients, responsible for the formation of these fronts. Results highlight that the stirring properties of the flow at depth, which are related to the velocity gradients, can be inferred from finite-size Lyapunov exponent (FSLE) at the surface. Satellite altimetry observations of FSLE and velocity gradients are then used in combination with recent in situ observations collected by an elephant seal in the ACC to reconstruct frontal dynamics and their associated vertical velocities down to 500 m. The approach proposed here is well suited for the analysis of sub-mesoscale-resolving datasets and the design of future sub-mesoscale field campaigns

Role of the Fractalkine Receptor in CNS Autoimmune Inflammation: New Approach Utilizing a Mouse Model Expressing the Human CX3CR1

Multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system (CNS) is the leading cause of non-traumatic neurological disability in young adults. Immune mediated destruction of myelin and oligodendrocytes is considered the primary pathology of MS, but progressive axonal loss is the major cause of neurological disability. In an effort to understand microglia function during CNS inflammation, our laboratory focuses on the fractalkine/CX3CR1 signaling as a regulator of microglia neurotoxicity in various models of neurodegeneration. Fractalkine (FKN) is a transmembrane chemokine expressed in the CNS by neurons and signals through its unique receptor CX3CR1 present in microglia. During experimental autoimmune encephalomyelitis (EAE), CX3CR1 deficiency confers exacerbated disease defined by severe inflammation and neuronal loss. The CX3CR1 human polymorphism I249/M280 present in ∼20% of the population exhibits reduced adhesion for FKN conferring defective signaling whose role in microglia function and influence on neurons during MS remains unsolved. The aim of this study is to assess the effect of weaker signaling through hCX3CR1I249/M280 during EAE. We hypothesize that dysregulated microglial responses due to impaired CX3CR1 signaling enhance neuronal/axonal damage. We generated an animal model replacing the mouse CX3CR1 locus for the hCX3CR1I249/M280 variant. Upon EAE induction, these mice exhibited exacerbated EAE correlating with severe inflammation and neuronal loss. We also observed that mice with aberrant CX3CR1 signaling are unable to produce FKN and ciliary neurotrophic factor during EAE in contrast to wild type mice. Our results provide validation of defective function of the hCX3CR1I249/M280 variant and the foundation to broaden the understanding of microglia dysfunction during neuroinflammation. © 2018 Cardona et al

Association between Total Body Composition and VO2max in Individuals with Mid-Spectrum Chronic Kidney Disease

Total body composition (TBC), a measure of body fat percentage (%BF), lean body mass (LBM), and bone mineral content (BMC), can be used as a predictor of cardiovascular fitness. Prior studies have established a relationship between TBC and VO2max in healthy individuals over 35 years of age. However, this relationship is poorly understood in chronic disease populations. PURPOSE: To assess the relationship between TBC and cardiovascular fitness in a clinical population of adults with mid-spectrum (stages G2, G3a, and G3b) chronic kidney disease (CKD). METHODS: A cross-sectional analysis was conducted among 24 subjects diagnosed with mid-spectrum CKD. Nine males and 15 females with an average age of 62.25±9.2 years and a glomerular filtration rate (GFR) of 54.38±9.04 ml/min/1.73m2 completed the study. Subjects completed a health screening, dual-energy x-ray absorptiometry (DEXA) scan, and underwent VO2max testing on a treadmill using a modified Bruce protocol. Normality tests, descriptive statistics, Pearson’s correlations, t-tests, and ANOVAs were conducted in SAS v.9.4. RESULTS: The average %BF was 36.28±8.47%, LBM was 117.16±31.32lbs., BMC was 2308.74±735.19g., and VO2max was 20.13±5.04ml/kg/min. VO2max was positively correlated with BMC and LBM (r=0.65, p=0.001 and r=0.75, p\u3c0.001, respectively) and negatively correlated with %BF (r= -0.80, p\u3c0.001). Individuals in later stages of CKD had lower LBM, BMC, and VO2max (p=0.017, p=0.001, and p=0.007, respectively), yet there was no association of CKD stage with %BF or age (p=0.210 and p=0.107). CONCLUSION: TBC was found to be significantly associated with cardiovascular fitness in the study sample. Higher BMD and LBM values were associated with higher VO2max whereas higher %BF was associated with a lower VO2max in individuals with mid-spectrum CKD. Progression of CKD stage was associated with lower LBM, BMC, and VO2max values, indicating a graded effect of CKD stage on cardiovascular fitness

Vitamin D Association with Renal Health and Filtration in Healthy Individuals Free of Cardiometabolic Diseases: A Pilot Study

The effect of vitamin D (VITD) on bone, muscle, and over health is well know in renal failure and chronic kidney disease (CKD). However, the influence of VITD on renal health and filtration (RHF) in healthy individuals is unclear. Currently, only serum creatinine concentration (sCr) methods are used to assess renal status in health individuals. However, newer biomarkers like serum Cystatin C (CyC) and urine epidermal growth factor (uEGF) show promise in evaluating baseline RHF. The impact of Vitamin D on filtration in healthy individuals of various ages is still unknown. PURPOSE: To determine the impact of VITD on RHF in healthy individuals of middle-aged status. METHODS: Thirty-six participants (n = 22 men; n = 14 women; age 37.6 + 12.4 yr; BF% 19.2 + 7.1%) agreed to participate in the research study. Blood and urine samples were obtained under standardized conditions for all individuals. VITD, CyC, uEGF, urine creatinine (uCr), uCr/uEGF ratio, sCR, and multiple estimates of glomerular filtration rate (eGFR) - modification of diet in renal disease (MDRD), CKD-EPI, CyC equations (CyC only and CyC combined with sCr) were assessed as a whole cohort and grouped (young = 20-39 yrs. (n = 22), older = 40-60 yrs. (n = 14)). Analysis was done using a paired sample t-tests, Pearson Correlation to compare VITD concentrations and markers of RHF. Linear regression analyses was performed to examine the relationship between VITD ability to predict RHF. All analyses were performed using SPSS (v. 28.0.1.1). RESULTS: There was no significant correlations found between VITD and markers of RHF in the entire cohort. Therefore, no predictive model was performed. The younger group showed strong negative correlation between VITD and MDRD (r = -0.575, p = 0.008), and that VITD was able to predict MDRD (R2 = 0.331, p = 0.008). No significant correlation observed in older group. CONCLUSIONS: VITD was correlated and able to predict a marker of RHF in healthy younger individuals, but not in older individuals. Based on the sample size and overall outcomes, continued research is needed to more accurately determine VITD effects on RHF in healthy populations

Adult Willingness to Use Email and Social Media for Peer-to-Peer Cancer Screening Communication: Quantitative Interview Study

BACKGROUND: Adults over age 40 are increasing their use of email and social media, raising interest in use of peer-to-peer Internet-based messaging to promote cancer screening. OBJECTIVE: The objective of our study was to assess current practices and attitudes toward use of email and other e-communication for peer-to-peer dialogues on cancer screening. METHODS: We conducted in-person interviews with 438 insured adults ages 42-73 in Georgia, Hawaii, and Massachusetts. Participants reported on use of email and other e-communication including social media to discuss with peers routine health topics including breast and colorectal cancer (CRC). We ascertained willingness to share personal CRC screening experiences via conversation, postcard, email, or other e-communication. Health literacy scores were measured. RESULTS: Email had been used by one-third (33.8%, 148/438) to discuss routine health topics, by 14.6% (64/438) to discuss breast cancer screening, and by 12.6% (55/438) to discuss CRC screening. Other e-communication was used to discuss routine health topics (11.6%, 51/438), screening for breast cancer (3.9%, 17/438), and CRC (2.3%, 10/438). In the preceding week, 84.5% (370/438) of participants had used email, 55.9% (245/438) had used e-communication of some type; 44.3% (194/438) text, 32.9% (144/438) Facebook, 12.3% (54/438) instant message, 7.1% (31/438) video chat, and 4.8% (21/438) Twitter. Many participants were willing to share their CRC screening experiences via email (32.4%, 142/438 might be willing; 36.3%, 159/438 very willing) and via other e-communication (15.8%, 69/438 might be willing; 14.4%, 63/438 very willing). Individuals willing to send CRC screening emails scored significantly higher on tests of health literacy compared to those willing to send only postcards (P\u3c.001). CONCLUSIONS: Many adults are willing to use email and e-communication to promote cancer screening to peers. Optimal approaches for encouraging peer-to-peer transmission of accurate and appropriate cancer screening messages must be studied

GJ 3236: a new bright, very low-mass eclipsing binary system discovered by the MEarth observatory

We report the detection of eclipses in GJ 3236, a bright (I = 11.6) very low mass binary system with an orbital period of 0.77 days. Analysis of light- and radial velocity curves of the system yielded component masses of 0.38 +/- 0.02 and 0.28 +/- 0.02 Msol. The central values for the stellar radii are larger than the theoretical models predict for these masses, in agreement with the results for existing eclipsing binaries, although the present 5% observational uncertainties limit the significance of the larger radii to approximately 1 sigma. Degeneracies in the light curve models resulting from the unknown configuration of surface spots on the components of GJ 3236 currently dominate the uncertainties in the radii, and could be reduced by obtaining precise, multi-band photometry covering the full orbital period. The system appears to be tidally synchronized and shows signs of high activity levels as expected for such a short orbital period, evidenced by strong Halpha emission lines in the spectra of both components. These observations probe an important region of mass-radius parameter space around the predicted transition to fully-convective stellar interiors, where there are a limited number of precise measurements available in the literature.Comment: 14 pages, 5 figures, 10 tables, emulateapj format. Accepted for publication in Ap