Constructing infinitely many smooth structures on small 4-manifolds

The purpose of this article is twofold. First we outline a general construction scheme for producing simply-connected minimal symplectic 4-manifolds with small Euler characteristics. Using this scheme, we illustrate how to obtain irreducible symplectic 4-manifolds homeomorphic but not diffeomorphic to \CP#(2k+1)\CPb for $k = 1,...,4$, or to 3\CP# (2l+3)\CPb for $l =1,...,6$. Secondly, for each of these homeomorphism types, we show how to produce an infinite family of pairwise nondiffeomorphic nonsymplectic 4-manifolds belonging to it. In particular, we prove that there are infinitely many exotic irreducible nonsymplectic smooth structures on \CP#3\CPb, 3\CP#5\CPb and 3\CP#7\CPb.Comment: 23 pages, 3 figure

Direct Evidence for Multiferroic Magnetoelectric Coupling in 0.9BiFeO(3)-0.1BaTiO(3)

Magnetic, dielectric and calorimetric studies on 0.9BiFeO(3)-0.1BaTiO(3) indicate strong magnetoelectric coupling. XRD studies reveal a very remarkable change in the rhombohedral distortion angle and a significant shift in the atomic positions at the magnetic T-c due to an isostructural phase transition. The calculated polarization using Rietveld refined atomic positions scales linearly with magnetization. Our results provide the first unambiguous, atomic level evidence for magnetoelectric coupling of intrinsic multiferroic origin in a BiFeO3-based system

Simply connected minimal symplectic 4-manifolds with signature less than - 1

For each pair (e,σ) of integers satisfying 2e + 3σ ≥ 0, σ ≤ - 2, and e + σ ≡0 (mod 4), with four exceptions, we construct a minimal, simply connected symplectic 4-manifold with Euler characteristic e and signature σ. We also produce simply connected, minimal symplectic 4-manifolds with signature zero (resp. signature-1) with Euler characteristic 4k (resp. 4k + 1) for all k ≥ 46 (resp. k ≥ 49). © European Mathematical Society 2010

Prediction and Inhibition of Inorganic Salt Formation under Static and Dynamic Conditions – Effect of Pressure, Temperature, and Mixing Ratio

As a result of waterflooding, inorganic salt precipitation occurs in the different parts of an oil production system, thereby leading to damage of production equipment. Different parameters affect the kinetics of salt precipitation. Scale inhibitors are widely used to prevent inorganic salt formation. In this study, the effect of reservoir pressure, temperature, and mixing ratio of injection to formation water on calcium sulfate and barium sulfate precipitation was investigated. For this purpose, two different formation waters and one injection water were used. In addition, the effect of temperature and mixing ratio on inhibition performance was studied. Four different existing industrial scale inhibitors and one new scale inhibitor were used. The performance of the scale inhibitors was determined under static and dynamic conditions. Results of the study showed that calcium sulfate precipitation increased with an increase in temperature and a decrease in pressure. Barium sulfate precipitation was found to increase with a decrease in the temperature. The effect of pressure on barium sulfate formation was negligible. The developed scale inhibitor showed the highest performance for the prevention of calcium sulfate and barium sulfate formation. A change in temperature from 60°C to 120°C reduced the inhibitor performance by 3%. In the cases of calcium sulfate and barium sulfate, the minimum performance of the scale inhibitor was observed when the mixing ratios of injection to formation waters were 60:40 and 50:50, respectively

Exotic Smooth Structures on Small 4-Manifolds

Let M be either CP^2#3CP^2bar or 3CP^2#5CP^2bar. We construct the first example of a simply-connected symplectic 4-manifold that is homeomorphic but not diffeomorphic to M.Comment: 11 page

Insulin Resistance and Contrainsular Response in Type 2 Diabetes Mellitus Patients with Acute Coronary Syndrome

BACKGROUND: The number of patients with diabetes mellitus (DM) is progressively increasing all over the world. Over the past three decades, the global burden of diabetes has increased from 30 million in 1985 to 382 million in 2015, and current trends indicate that the prevalence of diabetes grows progressively. The phenomenon of insulin resistance established in the majority of type 2 DM (T2DM) patients. T2DM is associated with β-cell deficiency, α-cell resistance to insulin, and reduced effects of incretin. However, the role of insulin and glucagon in the process of cardiovascular complications in diabetic patients is a matter of debate. AIM: Our study aims to estimate insulin resistance and the contrainsular response in patients with T2DM and acute coronary syndrome (ACS). METHODS: The 104 T2DM patients aged 18–70 years participated in the observational study carried out in the Karaganda regional cardiosurgery hospital and ambulatory. The first group included 37 patients hospitalized for ACS in the first 24 h of admission. The second group included 67 patients without ACS. Determination of insulin resistance and contrainsular response was provided using a multiplex immunological assay with XMap technology on Bioplex 3D. RESULTS: During the research, we have discovered a decreased level of glucagon and increased homeostasis model assessment of insulin resistance (HOMA-IR) in patients with T2DM diabetes and ACS. Evaluation of traditional correlation interactions of HOMA-IR and indicators of carbohydrate metabolism showed a positive correlation with fasting plasma glucose in both study groups (Group 1: R = 0.47, p = 0.003; Group 2: R = 0.41, p = 0.024). Glucagon-like peptide (GLP)-1 has a weak positive correlation with HOMA-IR only in the first group (R = 0.32, p = 0.006). Increased insulin resistance was associated with high GLP-1 levels and low glucagon. The logistic regression model established that an increased HOMA-IR index rises the chance of ACS by 10.6% (OR = 1.106 [95% CI 1.105–1.206], p = 0,021). The logistic regression model, reflecting the relation between glucagon and ACS, shows that increased glucagon reduces the ACS odds (OR = 0.989 [95% CI 0.979–0.999], p = 0.026). The adjusted regression model showed no significant influence of early presented factors on the probability of ACS. CONCLUSION: There is a trend toward elevated HOMA-IR insulin resistance index and decreased level of glucagon in diabetic patients with ACS

Exotic smooth structures on 4-manifolds with zero signature

For every integer $k\geq 2$, we construct infinite families of mutually nondiffeomorphic irreducible smooth structures on the topological $4$-manifolds $(2k-1)(S^2\times S^2)$ and (2k-1)(\CP#\CPb), the connected sums of $2k-1$ copies of $S^2\times S^2$ and \CP#\CPb.Comment: 6 page

Regulation of cell migration and survival by focal adhesion targeting of Lasp-1

Large-scale proteomic and functional analysis of isolated pseudopodia revealed the Lim, actin, and SH3 domain protein (Lasp-1) as a novel protein necessary for cell migration, but not adhesion to, the extracellular matrix (ECM). Lasp-1 is a ubiquitously expressed actin-binding protein with a unique domain configuration containing SH3 and LIM domains, and is overexpressed in 8–12% of human breast cancers. We find that stimulation of nonmotile and quiescent cells with growth factors or ECM proteins facilitates Lasp-1 relocalization from the cell periphery to the leading edge of the pseudopodium, where it associates with nascent focal complexes and areas of actin polymerization. Interestingly, although Lasp-1 dynamics in migratory cells occur independently of c-Abl kinase activity and tyrosine phosphorylation, c-Abl activation by apoptotic agents specifically promotes phosphorylation of Lasp-1 at tyrosine 171, which is associated with the loss of Lasp-1 localization to focal adhesions and induction of cell death. Thus, Lasp-1 is a dynamic focal adhesion protein necessary for cell migration and survival in response to growth factors and ECM proteins

Comparison of embryologist stress, somatization and burnout reported by embryologists working in UK HFEA-licensed ART/IVF clinics and US ART/IVF clinics

STUDY QUESTION What is the prevalence of occupational stress, somatization, and burnout reported by UK and US, embryologists and the impact of work conditions on these well-being outcomes? SUMMARY ANSWER Surveyed UK and US embryologists reported moderate perceived stress, low somatic symptom severity, high levels of burnout, and overall stressful work conditions, but with differences that could be due to country-specific occupational and employment characteristics. WHAT IS KNOWN ALREADY? Spanish, UK, US, and international surveys have identified high levels of occupational stress, somatization, burnout, and occupational health issues among embryologists. These issues have been attributed to embryologists’ occupational challenges and work conditions. STUDY DESIGN, SIZE, DURATION A cross-sectional web-based survey was sent to 253 embryologists working in UK ART/IVF clinics and 487 embryologists working in US ART/IVF clinics. PARTICIPANTS/MATERIALS, SETTING, METHODS Participants self-reported their stress levels, somatization, burnout, and work conditions. Proportions across the Perceived Stress Scale (PSS), Patient Health Questionnaire (PHQ-15), Maslach Burnout Inventory-General Survey (MBI-GS), a single-item work unit grade (A–F), and customized occupational and sociodemographic questionnaires were calculated using descriptive statistics. Welch’s t-test was utilized to compare PSS and PHQ-15 scores between groups. Risk ratios were calculated using log-binomial regression for all models except for levels of anxiety related to performing cryostorage tasks, for which Poisson models were used. MAIN RESULTS AND THE ROLE OF CHANCE In total, 50.6% (128) of the embryologists in the UK and 50.1% (244) in the US completed the survey. Both groups self-reported moderate PSS and low PHQ-15 scores, although fewer UK embryologists scored high on the MBI cynicism dimension than their US colleagues (43% UK vs 60% US embryologists, P < 0.05). The UK and US embryologists did not differ on the MBI exhaustion dimension with both scoring high for exhaustion (59% UK vs 62% US). Although 81% and 80% of UK and US embryologists, respectively, reported working overtime, more embryologists in the UK reported being adequately compensated. Increasing levels of anxiety-related to cryostorage showed a dose-dependent increased risk of burnout on at least two MBI-GS dimensions only in the UK group, and, a dose-dependent likelihood of higher PSS and PHQ-15 scores in both groups. LIMITATIONS, REASONS FOR CAUTION Since the two groups were surveyed 9 months apart and were self-reporting, the study is limited by the differences in responsibilities, scheduling, and workload specific to the time of year. WIDER IMPLICATIONS OF THE FINDINGS Work-related health issues and occupational challenges shared by UK and US embryologists could be addressed by organizational enhancements and technology. Lower levels of stress and burnout among UK embryologists might be due to the HFEA-provided structure/certainty. STUDY FUNDING/COMPETING INTEREST(S) This study was supported without any external funding by TMRW Life Sciences Inc., which is developing and commercializing an automated platform for embryology. M.G.C. and M.S.L. are full-time employees and stockholders/shareholders with TMRW Life Sciences, and A.M. of Novavax, Inc. was an employee of TMRW Life Sciences. G.P. is a consultant for TMRW Life Sciences. The remaining authors declare no conflict of interest. TRIAL REGISTRATION NUMBER NCT05326802; NCT05708963