List decoding of noisy Reed-Muller-like codes

First- and second-order Reed-Muller (RM(1) and RM(2), respectively) codes are two fundamental error-correcting codes which arise in communication as well as in probabilistically-checkable proofs and learning. In this paper, we take the first steps toward extending the quick randomized decoding tools of RM(1) into the realm of quadratic binary and, equivalently, Z_4 codes. Our main algorithmic result is an extension of the RM(1) techniques from Goldreich-Levin and Kushilevitz-Mansour algorithms to the Hankel code, a code between RM(1) and RM(2). That is, given signal s of length N, we find a list that is a superset of all Hankel codewords phi with dot product to s at least (1/sqrt(k)) times the norm of s, in time polynomial in k and log(N). We also give a new and simple formulation of a known Kerdock code as a subcode of the Hankel code. As a corollary, we can list-decode Kerdock, too. Also, we get a quick algorithm for finding a sparse Kerdock approximation. That is, for k small compared with 1/sqrt{N} and for epsilon > 0, we find, in time polynomial in (k log(N)/epsilon), a k-Kerdock-term approximation s~ to s with Euclidean error at most the factor (1+epsilon+O(k^2/sqrt{N})) times that of the best such approximation

The Degradation of Acetaminophen in Water using Bleach

Acetaminophen is a very common antipyretic, mainly found in Tylenol. Because of climate change, there will be a time when climate change related weather events such as heavy rainfall, will cause the destruction of water supply infrastructure, lower the water resource availability, and reduce the quality of consumable water. As of 2020, only 30% of rural populations in the poorest countries have water that is clean of fecal and priority chemical contaminants, showing how important the removal of acetaminophen from water is. The main way acetaminophen gets into ground water is though excretion after consumption, and when flushing unwanted medication that contains acetaminophen. Up to 9% of initial acetaminophen is excreted after being metabolized through the body. The use of a bleach tablet in the toilet bowl will degrade the acetaminophen before being flushed. Even small concentrations of acetaminophen influence fish populations including disturbing normal development of the embryos. Solutions of 5 and 10 ppm acetaminophen were made to convey the concentration of acetaminophen that may be found in the environment. Both were inserted into a UV-Vis spectrophotometer. The λmax was found to be 242.5 nm for both solutions which was needed for the UV detector on the HPLC. The 10 ppm acetaminophen and water solution was run in the HPLC. A good mobile phase is important for the resolution and separation of peaks of the chromatogram. The solvent composition was 94.5:5.5 water:acetonitrile solution, which produced a sharp peak at 3.5 minutes. All trials had a flow rate of 1.5 mL/min and ran for 10 minutes. After seeing inconsistency in retention times, the solvent was improved to take 0.4% of the HPLC grade water, to make room for 0.2% triethylamine and 0.2% acetic acid. All solvents (water, acetonitrile, triethylamine and acetic acid) were combined into the same container to improve the difference in viscosity between water and acetonitrile, which was adding pulses in the chromatograms at a consistent time (every 0.5 minutes). A rerun of all samples (1, 2, 3, 4. 5 and 10 ppm) with all siphons in the one solvent, were done to find a peak at about 6.5 minutes. From this data, a calibration curve was made based on concentration of acetaminophen. The line of best fit equation is y=495327x+570950 with an R2 value of 0.8732. Preliminary kinetic experiments measuring the effect of bleach an acetaminophen degradation are ongoing

Approximate Sparse Recovery: Optimizing Time and Measurements

An approximate sparse recovery system consists of parameters $k,N$, an $m$-by-$N$ measurement matrix, $\Phi$, and a decoding algorithm, $\mathcal{D}$. Given a vector, $x$, the system approximates $x$ by $\widehat x =\mathcal{D}(\Phi x)$, which must satisfy $\| \widehat x - x\|_2\le C \|x - x_k\|_2$, where $x_k$ denotes the optimal $k$-term approximation to $x$. For each vector $x$, the system must succeed with probability at least 3/4. Among the goals in designing such systems are minimizing the number $m$ of measurements and the runtime of the decoding algorithm, $\mathcal{D}$. In this paper, we give a system with $m=O(k \log(N/k))$ measurements--matching a lower bound, up to a constant factor--and decoding time $O(k\log^c N)$, matching a lower bound up to $\log(N)$ factors. We also consider the encode time (i.e., the time to multiply $\Phi$ by $x$), the time to update measurements (i.e., the time to multiply $\Phi$ by a 1-sparse $x$), and the robustness and stability of the algorithm (adding noise before and after the measurements). Our encode and update times are optimal up to $\log(N)$ factors

Amiloride reduces portal hypertension in rat liver cirrhosis

Objective This study aimed to investigate the effect of amiloride on portal hypertension. Amiloride is known to inhibit Na(+)/H(+) exchangers on activated hepatic stellate cells. Methods Liver cirrhosis in rats was induced by bile duct ligation (BDL) or thioacetamide (TAA) administration. The effects of zymosan for Kupffer cell (KC) activation or a thromboxane (TX) analogue (U46619) were tested in isolated perfused livers of cirrhotic rats and in vivo. Downstream mechanisms were investigated using Rho kinase inhibitor (Y-27632) or amiloride. Acute and chronic effects of amiloride and canrenoate on portal pressure were compared in perfused livers and in vivo. TXB(2) efflux was measured by ELISA. The phosphorylation state of moesin (p-moesin) as an indicator of Rho kinase activity and expression of the thromboxane synthase were assessed by western blot analyses. The activity of hepatic stellate cells was analysed by western blot and staining for alpha-smooth muscle actin (alpha-SMA). Results In BDL rats, KC activation via zymosan increased portal pressure. This was attenuated by the Rho kinase inhibitor Y-27632. Increased thromboxane efflux following zymosan infusion remained unaltered by Y-27632. The infusion of amiloride attenuated zymosan- and U46619-induced increases in portal perfusion pressure. In vivo, direct administration of amiloride, but not of canrenoate, lowered portal pressure. In TAA and BDL rats, treatment with amiloride for 3 days reduced basal portal pressure and KC-induced increases in portal pressure whereas canrenoate had no effect. In livers of amiloride-treated animals, the phosphorylation state of moesin and the number of alpha-SMA positive cells were reduced. Conclusions Amiloride lowers portal pressure in rat liver cirrhosis by inhibition of intrahepatic vasocontraction. Therefore, patients with cirrhosis and portal hypertension may benefit from amiloride therapy

Risk factors for anxiety and depression among pregnant women during the COVID-19 pandemic: Results of a web-based multinational cross-sectional study.

Objective To assess risk factors for anxiety and depression among pregnant women during the COVID-19 pandemic using Mind-COVID, a prospective cross-sectional study that compares outcomes in middle-income economies and high-income economies. Methods A total of 7102 pregnant women from 12 high-income economies and nine middle-income economies were included. The web-based survey used two standardized instruments, General Anxiety Disorder-7 (GAD-7) and Patient Health Questionnaire–9 (PHQ-9). Result Pregnant women in high-income economies reported higher PHQ-9 (0.18 standard deviation [SD], P < 0.001) and GAD-7 (0.08 SD, P = 0.005) scores than those living in middle-income economies. Multivariate regression analysis showed that increasing PHQ-9 and GAD-7 scales were associated with mental health problems during pregnancy and the need for psychiatric treatment before pregnancy. PHQ-9 was associated with a feeling of burden related to restrictions in social distancing, and access to leisure activities. GAD-7 scores were associated with a pregnancy-related complication, fear of adverse outcomes in children related to COVID-19, and feeling of burden related to finances. Conclusions According to this study, the imposed public health measures and hospital restrictions have left pregnant women more vulnerable during these difficult times. Adequate partner and family support during pregnancy and childbirth can be one of the most important protective factors against anxiety and depression, regardless of national economic status.pre-print2752 K

UK stroke incidence, mortality and cardiovascular risk management 1999–2008: time-trend analysis from the General Practice Research Database

Objectives Stroke is a major cause of morbidity and mortality. This study aimed to investigate secular trends in stroke across the UK. Design This study aimed to investigate recent trends in the epidemiology of stroke in the UK. The study was a time-trend analysis from 1999 to 2008 within the UK General Practice Research Database. Outcome measures were incidence and prevalence of stroke, stroke mortality, rate of secondary cardiovascular events, and prescribing of pharmacological therapy for primary and secondary prevention of cardiovascular disease. Results The study cohort included 32 151 patients with a first stroke. Stroke incidence fell by 30%, from 1.48/1000 person-years in 1999 to 1.04/1000 person-years in 2008 (p<0.001). Stroke prevalence increased by 12.5%, from 6.40/1000 in 1999 to 7.20/1000 in 2008 (p<0.001). 56-day mortality after first stroke reduced from 21% in 1999 to 12% in 2008 (p<0.0001). Prescribing of drugs to control cardiovascular risk factors increased consistently over the study period, particularly for lipid lowering agents and antihypertensive agents. In patients with atrial fibrillation, use of anticoagulants prior to first stroke did not increase with increasing stroke risk. Conclusion Stroke incidence in the UK has decreased and survival after stroke has improved in the past 10 years. Improved drug treatment in primary care is likely to be a major contributor to this, with better control of risk factors both before and after incident stroke. There is, however, scope for further improvement in risk factor reduction in high-risk patients with atrial fibrillation

The COMBS survey I : Chemical Origins of Metal-Poor Stars in the Galactic Bulge

19 pages, 5 tables, accepted to MNRASChemistry and kinematic studies can determine the origins of stellar population across the Milky Way. The metallicity distribution function of the bulge indicates that it comprises multiple populations, the more metal-poor end of which is particularly poorly understood. It is currently unknown if metal-poor bulge stars ([Fe/H] <−1 dex) are part of the stellar halo in the inner most region, or a distinct bulge population or a combination of these. Cosmological simulations also indicate that the metal-poor bulge stars may be the oldest stars in the Galaxy. In this study, we successfully target metal-poor bulge stars selected using SkyMapper photometry. We determine the stellar parameters of 26 stars and their elemental abundances for 22 elements using R∼ 47 000 VLT/UVES spectra and contrast their elemental properties with that of other Galactic stellar populations. We find that the elemental abundances we derive for our metal-poor bulge stars have lower overall scatter than typically found in the halo. This indicates that these stars may be a distinct population confined to the bulge. If these stars are, alternatively, part of the innermost distribution of the halo, this indicates that the halo is more chemically homogeneous at small Galactic radii than at large radii. We also find two stars whose chemistry is consistent with second-generation globular cluster stars. This paper is the first part of the Chemical Origins of Metal-poor Bulge Stars (COMBS) survey that will chemodynamically characterize the metal-poor bulge population.Peer reviewedFinal Published versio

Effects of Visual/Verbal Associations

Different effects of instructional strategies on recall and comprehension of terms frequently used in formal analysis of art were examined. The study looked at a synthesis of three theoretical positions: dual-coding theory; schema theory; and elaboration theory. Two-hundred and fifty sixth-grade students were randomly assigned to three groups: control subjects; graphic subjects; and transformational subjects. Instruments consisted of Raven\u27s Standard Progressive Matrices (RSPM) and the Art Vocabulary Test (AVT). The program consisted of three phases: (1) a 10-minute study session; (2) an interactive discussion; and (3) a drawing task. The results suggested that imagery strategies help students form and retain associations between verbal and visual information. Graphic organizers may promote more flexible applications of the associations for individuals who have already acquired good problem-solving skills. The concrete associations obtained from transformational imagery strategies improve student recall of specific associations. However; interview data suggested that the approach may constrain the associated meaning. Trends in the data are consistent with elaboration theory and could inform scholars and researchers who wish to analyze effects of visual and verbal associations. (KM