We present the power spectrum of the reconstructed halo density field derived from a sample of luminous red galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS) Seventh Data Release (DR7). The ...halo power spectrum has a direct connection to the underlying dark matter power for k≤ 0.2 h Mpc−1, well into the quasi-linear regime. This enables us to use a factor of ∼8 more modes in the cosmological analysis than an analysis with kmax= 0.1 h Mpc−1, as was adopted in the SDSS team analysis of the DR4 LRG sample. The observed halo power spectrum for 0.02 < k < 0.2 h Mpc−1 is well fitted by our model: χ2= 39.6 for 40 degrees of freedom for the best-fitting Λ cold dark matter (ΛCDM) model. We find Ωmh2(ns/0.96)1.2= 0.141+0.010−0.012 for a power-law primordial power spectrum with spectral index ns and Ωbh2= 0.022 65 fixed, consistent with cosmic microwave background measurements. The halo power spectrum also constrains the ratio of the comoving sound horizon at the baryon-drag epoch to an effective distance to z= 0.35: rs/DV(0.35) = 0.1097+0.0039−0.0042. Combining the halo power spectrum measurement with the Wilkinson Microwave Anisotropy Probe (WMAP) 5 year results, for the flat ΛCDM model we find Ωm= 0.289 ± 0.019 and H0= 69.4 ± 1.6 km s−1 Mpc−1. Allowing for massive neutrinos in ΛCDM, we find eV at the 95 per cent confidence level. If we instead consider the effective number of relativistic species Neff as a free parameter, we find Neff= 4.8+1.8−1.7. Combining also with the Kowalski et al. supernova sample, we find Ωtot= 1.011 ± 0.009 and w=−0.99 ± 0.11 for an open cosmology with constant dark energy equation of state w. The power spectrum and a module to calculate the likelihoods are publicly available at http://lambda.gsfc.nasa.gov/toolbox/lrgdr/.
Household food insecurity is associated with poor dietary intake in the general population, but little is known about this association in persons with diabetes.
We examined the degree of adherence to ...the dietary reference intakes and 2020-2025 Dietary Guidelines for Americans overall and according to food security status and diabetes type among youth and young adults (YYA) with youth-onset diabetes.
The SEARCH for Diabetes in Youth study includes 1,197 YYA with type 1 diabetes (mean age = 21 ± 5 years) and 319 YYA with type 2 diabetes (25 ± 4 years). Participants (or parents if younger than age 18 years) completed the US Department of Agriculture Household Food Security Survey Module, wherein ≥3 affirmations indicate food insecurity.
Diet was assessed via food frequency questionnaire and compared with age- and sex-specific dietary reference intakes for 10 nutrients and dietary components (calcium; fiber; magnesium; potassium; sodium; vitamins C, D, and E; added sugar; and saturated fat).
Median regression models controlled for sex- and type-specific means for age, diabetes duration, and daily energy intake.
Prevalence of guideline adherence was overarchingly poor, with <40% of participants meeting recommendations for eight of 10 nutrients and dietary components; however, higher adherence (>47%) was observed for vitamin C and added sugars. YYA with type 1 diabetes who were food insecure were more likely to meet recommendations for calcium, magnesium, and vitamin E (P < 0.05), and less likely for sodium (P < 0.05) than those with food security. In adjusted models, YYA with type 1 diabetes who were food secure had closer median adherence to sodium (P = 0.002) and fiber (P = 0.042) guidelines than those food insecure. No associations were observed in YYA with type 2 diabetes.
Food insecurity is associated with lesser adherence to fiber and sodium guidelines in YYA with type 1 diabetes, which may lead to diabetes complications and other chronic diseases.
The protective surfaces of bacteria are comprised of polysaccharides and are involved in host invasion and colonization, host immune system evasion, and antibacterial resistance. A major barrier to ...our fundamental understanding of these complex surface polysaccharides lies in the tremendous diversity in glycan composition among bacterial species. The polyisoprenoid bactoprenyl phosphate (or undecaprenyl phosphate) is an essential lipid carrier necessary for early stages of glycopolymer assembly. Because of the ubiquity of bactoprenyl phosphate in these critical processes, molecular probes appended to this lipid carrier simplify identification of enzymatic roles during polysaccharide bioassembly. A limited number of these probes exist in the literature or have been assessed with such pathways, and the limits of their use are not currently known. Herein, we devise an efficient method for producing fluorescently modified bactoprenyl probes. We further expand our previous efforts utilizing 2-nitrileaniline and additionally prepare nitrobenzoxadizol-tagged bactoprenyl phosphate for the first time. We then assess the enzyme promiscuity of these two probes utilizing four well-characterized initiating phosphoglycosyltransferases: CPS2E (Streptococcus pneumoniae), WbaP (Salmonella enterica), WecA (Escherichia coli), and WecP (Aeromonas hydrophilia). Both probes serve as substrates for these enzymes and could be readily used to investigate a wide range of bacterial glycoassembly pathways. Interestingly, we have also identified unique solubility requirements for the nitrobenzoxadizol moiety for efficient enzymatic utilization that was not observed for the 2-nitrileaniline.
To examine, among youth and young adults (YYA) with type 1 diabetes (T1D), the association of household food insecurity (HFI) with: 1) HbA1c and 2) episodes of diabetic ketoacidosis (DKA) and severe ...hypoglycemia.
HFI was assessed using the U.S. Household Food Security Survey Module in SEARCH for Diabetes in Youth participants with T1D between 2016 and 2019. Linear and logistic regression models adjusted for age, diabetes duration, sex, race, ethnicity, clinic site, parent/participant education, household income, health insurance, and diabetes technology use.
Of 1830 participants (mean age 20.8 ± 5.0 years, 70.0 % non-Hispanic White), HbA1c was collected for 1060 individuals (mean HbA1c 9.2 % ± 2.0 %). The prevalence of HFI was 16.4 %. In the past 12 months, 18.2 % and 9.9 % reported an episode of DKA or severe hypoglycemia, respectively. Compared to participants who were food secure, HFI was associated with a 0.33 % (95 % CI 0.003, 0.657) higher HbA1c level. Those with HFI had 1.58 (95 % CI 1.13, 2.21) times the adjusted odds of an episode of DKA and 1.53 (95 % CI 0.99, 2.37) times the adjusted odds of an episode of severe hypoglycemia as those without HFI.
HFI is associated with higher HbA1c levels and increased odds of DKA in YYA with T1D.
To evaluate the relation between household food insecurity (HFI) and fear of hypoglycemia among young adults with type 1 and type 2 diabetes and adolescents with type 1 diabetes and their parents.
We ...analyzed cross-sectional data of 1,676 young adults with youth-onset diabetes (84% type 1, 16% type 2) and 568 adolescents (<18 years old; mean age 15.1 years) with type 1 diabetes from the SEARCH for Diabetes in Youth study. Adult participants and parents of adolescent participants completed the U.S. Household Food Security Survey Module. Adults, adolescents, and parents of adolescents completed the Hypoglycemia Fear Survey, where answers range from 1 to 4. The outcomes were mean score for fear of hypoglycemia and the behavior and worry subscale scores. Linear regression models identified associations between HFI and fear of hypoglycemia scores.
Adults with type 1 diabetes experiencing HFI had higher fear of hypoglycemia scores (0.22 units higher for behavior, 0.55 units for worry, 0.40 units for total; all P < 0.0001) than those without HFI. No differences by HFI status were found for adolescents with type 1 diabetes. Parents of adolescents reporting HFI had a 0.18 unit higher worry score than those not reporting HFI (P < 0.05). Adults with type 2 diabetes experiencing HFI had higher fear of hypoglycemia scores (0.19 units higher for behavior, 0.35 units for worry, 0.28 units for total; all P < 0.05) than those in food secure households.
Screening for HFI and fear of hypoglycemia among people with diabetes can help providers tailor diabetes education for those who have HFI and therefore fear hypoglycemia.
We have carried out high contrast imaging of 70 young, nearby B and A stars to search for brown dwarf and planetary companions as part of the Gemini NICI Planet-Finding Campaign. Our survey ...represents the largest, deepest survey for planets around high-mass stars (approx =1.5-2.5 M sub(middot in circle)) conducted to date and includes the planet hosts beta Pic and Fomalhaut. We obtained follow-up astrometry of all candidate companions within 400 AU projected separation for stars in uncrowded fields and identified new low-mass companions to HD 1160 and HIP 79797. We have found that the previously known young brown dwarf companion to HIP 79797 is itself a tight (3 AU) binary, composed of brown dwarfs with masses 58 super(+21) sub(-20) M sub(Jup) and 55 super(+20) sub(-19) M sub(Jup), making this system one of the rare substellar binaries in orbit around a star. Considering the contrast limits of our NICI data and the fact that we did not detect any planets, we use high-fidelity Monte Carlo simulations to show that fewer than 20% of 2 M sub(middot in circle) stars can have giant planets greater than 4 M sub(Jup) between 59 and 460 AU at 95% confidence, and fewer than 10% of these stars can have a planet more massive than 10 M sub(Jup) between 38 and 650 AU. Overall, we find that large-separation giant planets are not common around B and A stars: fewer than 10% of B and A stars can have an analog to the HR 8799 b (7 M sub(Jup), 68 AU) planet at 95% confidence. We also describe a new Bayesian technique for determining the ages of field B and A stars from photometry and theoretical isochrones. Our method produces more plausible ages for high-mass stars than previous age-dating techniques, which tend to underestimate stellar ages and their uncertainties.
Group A Streptococcus (GAS) is a human-specific pathogen responsible for a number of diseases characterized by a wide range of clinical manifestations. During host colonization GAS-cell aggregates or ...microcolonies are observed in tissues. GAS biofilm, which is an in vitro equivalent of tissue microcolony, has only recently been studied and little is known about the specific surface determinants that aid biofilm formation. In this study, we demonstrate that surface-associated streptococcal collagen-like protein-1 (Scl1) plays an important role in GAS biofilm formation.
Biofilm formation by M1-, M3-, M28-, and M41-type GAS strains, representing an intraspecies breadth, were analyzed spectrophotometrically following crystal violet staining, and characterized using confocal and field emission scanning electron microscopy. The M41-type strain formed the most robust biofilm under static conditions, followed by M28- and M1-type strains, while the M3-type strains analyzed here did not form biofilm under the same experimental conditions. Differences in architecture and cell-surface morphology were observed in biofilms formed by the M1- and M41-wild-type strains, accompanied by varying amounts of deposited extracellular matrix and differences in cell-to-cell junctions within each biofilm. Importantly, all Scl1-negative mutants examined showed significantly decreased ability to form biofilm in vitro. Furthermore, the Scl1 protein expressed on the surface of a heterologous host, Lactococcus lactis, was sufficient to induce biofilm formation by this organism.
Overall, this work (i) identifies variations in biofilm formation capacity among pathogenically different GAS strains, (ii) identifies GAS surface properties that may aid in biofilm stability and, (iii) establishes that the Scl1 surface protein is an important determinant of GAS biofilm, which is sufficient to enable biofilm formation in the heterologous host Lactococcus. In summary, the GAS surface adhesin Scl1 may have an important role in biofilm-associated pathogenicity.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Cosmological analysis based on currently available observations are unable to rule out a sizeable coupling among the dark energy and dark matter fluids. We explore a variety of coupled dark ...matter-dark energy models, which satisfy cosmic microwave background constraints, in light of low redshift and near universe observations. We illustrate the phenomenology of different classes of dark coupling models, paying particular attention in distinguishing between effects that appear only on the expansion history and those that appear in the growth of structure. We find that while a broad class of dark coupling models are effectively models where general relativity (GR) is modified -- and thus can be probed by a combination of tests for the expansion history and the growth of structure --, there is a class of dark coupling models where gravity is still GR, but the growth of perturbations is, in principle modified. While this effect is small in the specific models we have considered, one should bear in mind that an inconsistency between reconstructed expansion history and growth may not uniquely indicate deviations from GR. Our low redshift constraints arise from cosmic velocities, redshift space distortions and dark matter abundance in galaxy voids. We find that current data constrain the dimensionless coupling to be
The enterobacterial common antigen (ECA), a three-sugar repeat unit polysaccharide produced by Enterobacteriaceae family members, impacts bacterial outer membrane permeability, and its biosynthesis ...affects the glycan landscape of the organism. ECA synthesis impacts the production of other polysaccharides by reducing the availability of shared substrates, the most notable of which is the 55-carbon polyisoprenoid bactoprenyl phosphate (BP), which serves as a carrier for the production of numerous bacterial glycans including ECA, peptidoglycan, O-antigen, and more. Here, using a combination of in vitro enzymatic synthesis and liquid chromatography–mass spectrometry (LC-MS) analysis of bacterial lysates, we provide biochemical evidence for the effect on endogenous polyisoprenoid pools from cell culture that arises from glycan pathway disruption. In this work, we have cloned and expressed each gene involved in ECA repeat unit biosynthesis and reconstituted the pathway in vitro, providing LC-MS characterized standards for the investigation of cellular glycan-linked intermediates and BP. We then generated ECA deficient mutants in genes associated with production of the polysaccharide, which we suspected would accumulate materials identical to our standards. We found that indeed accumulated products from these cells were indistinguishable from our enzymatically prepared standards, and moreover we observed a concomitant decrease in cellular BP levels with each mutant. This work provides the first direct biochemical evidence for the sequestration of BP upon the genetic disruption of glycan biosynthesis pathways in bacteria. This work also provides methods for the direct assessment of both the ECA glycan, and a new understanding of the dynamic interdependence of the bacterial polysaccharide repertoire.
Screening for household food insecurity (HFI) is recommended because of its impact on diabetes management. While HFI has been shown to be associated with poor glycemic control in adults with type 2 ...diabetes (T2D) and youth and young adults (YYA) with type 1, the association between HFI and glycemic control in YYA with T2D is not known.
This cross-sectional study included T2D YYA (n=395) from the 2015-2020 SEARCH for Diabetes in Youth Study (14-35 yrs; median age: 25.2 yrs). HFI was defined as affirming ≥3 items on the US Household Food Security Survey Module. HbA1c values were available for 271 participants. It was measured in a sample of whole blood and analyzed as a continuous variable. Glycemic control was dichotomized into optimal/suboptimal (≤9 %) vs. high risk (> 9.0%) based on HbA1c. Survey data on experiencing severe hypoglycemia or diabetic ketoacidosis (DKA) in the last 12 months was available for 292 participants. Logistic and linear regression were used for modeling the association of HFI with binary and continuous outcomes, respectively.
Approximately 34% of YYA with T2D reported HFI in the past 12 months. The mean HbA1c of the YYA with HFI was 9.2%, 54% had HbA1c >9.0%, and 19% reported experiencing DKA or hypoglycemia. YYA who were food secure had a mean HbA1c of 9.5%, 54% had HbA1c >9.0%, and 8% reported acute complications. No associations were observed between HFI and HbA1c or glycemic control. YYA with HFI had 2.3 (CI: 1.1-5.2) times the odds of experiencing DKA or hypoglycemia as those without HFI, after adjusting for age, gender, race, parent education, household income, insurance, clinic, diabetes duration, use of continuous glucose monitoring, and medication regimen. Our data suggests that HFI among YYA with T2D is a quite common, affecting more than a third of our sample and is associated with acute diabetes-related complications. These results warrant longitudinal studies in this particularly vulnerable group to establish if alleviating HFI reduces frequency of DKA and hypoglycemia episodes.
Disclosure
L. A. Reid: None. S. M. Marcovina: None. E. Lustigova: None. A. D. Liese: None. J. A. Mendoza: None. A. Merchant: None. M. Geraci: None. B. A. Reboussin: None. A. M. Ellyson: None. F. Malik: None. D. Dabelea: None. L. Merjaneh: None.
Funding
National Institutes of Health (R01DK117461, 1UC4DK108173)
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