Nonlinear rotations on a lattice

We consider a prototypical two-parameter family of invertible maps of $\mathbb{Z}^2$, representing rotations with decreasing rotation number. These maps describe the dynamics inside the island chains of a piecewise affine discrete twist map of the torus, in the limit of fine discretisation. We prove that there is a set of full density of points which, depending of the parameter values, are either periodic or escape to infinity. The proof is based on the analysis of an interval-exchange map over the integers, with infinitely many intervals.Comment: LaTeX, 34 pages with 4 figure

Middle Cranial Fossa Repair of Temporal Bone Spontaneous CSF Leaks With Hydroxyapatite Bone Cement

Objectives To determine the safety and effectiveness of the middle cranial fossa (MCF) approach in repairing spontaneous cerebrospinal fluid (sCSF) leaks. Study Design Retrospective cohort study. Methods Patient with sCSF leaks repaired by MCF approach between January 1, 2014 and August 31, 2019 were included. Demographic information, clinical and surgical findings, and postoperative outcomes were recorded. Results The cohort (n = 45) included 24 tegmen repairs by multilayer reconstruction using hydroxyapatite cement and 21 cases of multilayer repair without hydroxyapatite cement. Ten MCF repairs were performed on patients ≥65 years old. Twenty (53%) ears had multiple tegmen defects (range, 1–9 tegmen defects) and 78% of patients had ≥1 encephaloceles. All sCSF leaks were resolved with one surgical intervention. There were no major intracranial complications. Transient expressive aphasia occurred in 2 patients. Medical complications occurred in four patients. There were no short-term postoperative CSF leaks with bone cement reconstruction and two postoperative leaks without bone cement. One resolved with lumbar drain (LD) and the other resolved without treatment. The average (SD) length of stay (LOS) with bone cement was shorter than in patients without bone cement (2.54 [0.83] days vs. 3.52 [1.99] days, P < .05). There have been no long-term CSF leak recurrences with an average (SD) follow-up of 13.5 (12.9) months (range 0.25–46 months). Conclusions MCF approach for sCSF repairs demonstrate efficacious outcomes, particularly with tegmen reconstruction using hydroxyapatite cement. The approach exhibited no serious adverse events and few complications requiring intervention. Therefore, MCF is a safe and effective approach to resolve sCSF leaks

Investigation of the properties of quantum-dimensional semiconductor particles A3B5 by scanning probe microscopy, obtained by liquid chemical etching

The study was carried out with the financial support of the Russian Foundation for Basic Research in the framework of scientific projects 17-07-00407-а and 17-07-00139

Application of zero-truncated count data regression models to air-pollution disease

Count data consist of non-negative integers that have many applications in various fields of studies. To handle count data, there are various statistical models that can be employed corresponding to the properties of the count data studied. Poisson regression model (PRM) is mostly used to model data with equidispersion, while negative binomial regression model (NBRM) is a model that is regularly employed to model over-dispersed count data. On the other hand, the usual count data regression models may not able to handle strictly positive counts. In this case, the appropriate model for the analysis of such data would be models truncated at zero. We are interested to study the relationship between pollution related disease with influential factors such as air pollution and climate variables in Johor Bahru, Malaysia, using these zero-truncated models, where the number of disease cases are strictly positive. In particular, the zero-truncated PRM and NBRM are used to determine the association between the number of dengue patients and their influential factors. From the study, zero-truncated NBRM is found to be the best model amongst the two models to model the relationship between the number dengue cases and air pollution and climate. Air pollution factors that significantly affect the number of cases for dengue are particulate matter (PM10) and sulfur dioxide. Also, humidity and temperature are the climate factors that significantly affect the number of dengue cases

Experimental Investigation of Environmentally Friendly Drilling Fluid Additives (Mandarin Peels Powder) to Substitute the Conventional Chemicals Used in Water-Based Drilling Fluid

The non-biodegradable additives used in controlling drilling fluid properties cause harm to the environment and personal safety. Thus, there is a need for alternative drilling fluid additives to reduce the amount of non-biodegradable waste disposed to the environment. This work investigates the potential of using mandarin peels powder (MPP), a food waste product, as a new environmentally friendly drilling fluid additive. A complete set of tests were conducted to recognize the impact of MPP on the drilling fluid properties. The results of MPP were compared to low viscosity polyanionic cellulose (PAC-LV), commonly used chemical additive for the drilling fluid. The results showed that MPP reduced the alkalinity by 20-32% and modified the rheological properties (plastic viscosity, yield point, and gel strength) of the drilling fluid. The fluid loss decreased by 44-68% at concentrations of MPP as less as 1-4%, and filter cake was enhanced as well when comparing to the reference mud. In addition, MPP had a negligible to minor impact on mud weight, and this effect was resulted due to foaming issues. Other properties such as salinity, calcium content, and resistivity were negligibly affected by MPP. This makes MPP an effective material to be used as pH reducer, a viscosity modifier, and an excellent fluid loss agent. This work also provides a practical guide for minimizing the cost of the drilling fluid through economic, environmental, and safety considerations, by comparing MPP with PAC-LV

Experimental Investigation of Bio-Enhancer Drilling Fluid Additive: Can Palm Tree Leaves Be Utilized as a Supportive Eco-Friendly Additive in Water-Based Drilling Fluid System?

Serious problems will be presented due to using conventional chemical additives to regulate the drilling mud properties, as they have health, safety, and environmental side effects. Thus, there is a considerable necessity for alternative multifunctional bio-enhancer drilling mud additives, which can assist in optimizing the drilling fluid specifications and enhance its effectiveness with the least effects on the environment and the drilling personnel safety. The effects of adding two concentrations of palm tree leaves powder (PTLP) to water-based mud were conducted under fresh and aged conditions using standard API drilling fluids testing methods such as rheometer/viscometer, pH meter and temperature, and filter press. All tests results were minutely recorded to understand the influence of PTLP additives on the drilling mud properties. The results indicated that PTLP as an effective material to be used as pH reducer, viscosity reducer, and as an excellent filtration loss control agent under the surface and sub-surface conditions. Thus, PTLP has excellent feasibility to be utilized as biodegradable drilling mud additive replacing or at least supporting other conventional chemical additives, which have usually been used for the same purposes such as lignosulphonate, chrome-lignite, and Resinex. Finally, this work can serve as a practical guide for minimizing the cost of the drilling fluid and reducing the amount of non-biodegradable waste disposed to the environment

Cerebrospinal Fluid Leaks From the Lateral Ventricle: A Case Series

OBJECTIVES: Describe the diagnosis and management of lateral skull base (LSB) cerebrospinal fluid (CSF) leaks originating from the lateral ventricle. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral academic center. PATIENTS: Patients with CSF leaks with direct communication to the lateral ventricle on preoperative imaging. INTERVENTION: Surgical repair via the middle cranial fossa (MCF) approach. MAIN OUTCOME MEASURES: CSF leak patient characteristics (age, sex, body mass index [BMI]) and postoperative course (complications and CSF leak resolution) were collected. RESULTS: Three patients had CSF leaks from the lateral ventricle and all patients demonstrated encephalomalacia of the temporal lobe on preoperative imaging. Encephalomalacia resulted from trauma in one case (age 5) and neurodegeneration in two cases (age 77 and 84). BMI ranged from 16.3 to 26.6 mg/kg2 and follow-up ranged from 4 to 21 months. Two patients presented with preoperative meningitis and all patients had resolution of CSF leaks after MCF repair. With the exception of the higher rate of meningitis, patient presentations did not differ from other spontaneous CSF leaks through middle fossa defects. There were no minor or major postoperative complications. CONCLUSIONS: CSF leaks from the lateral ventricle represent a rare subset of LSB CSF leaks and can occur in non-obese patients secondary to temporal lobe encephalomalacia. The MCF approach allows for repair of the dura and skull base in this cohort of patients with high-flow CSF leaks and loss of brain parenchyma

The Impact of Insulin Pump Therapy on Glycemic Profiles in Patients with Type 2 Diabetes: Data from the OpT2mise Study

Background: The OpT2mise randomized trial was designed to compare the effects of continuous subcutaneous insulin infusion (CSII) and multiple daily injections (MDI) on glucose profiles in patients with type 2 diabetes. Research Design and Methods: Patients with glycated hemoglobin (HbA1c) levels of ≥8% (64 mmol/mol) and ≤12% (108 mmol/mol) despite insulin doses of 0.7-1.8 U/kg/day via MDI were randomized to CSII (n=168) or continued MDI (n=163). Changes in glucose profiles were evaluated using continuous glucose monitoring data collected over 6-day periods before and 6 months after randomization. Results: After 6 months, reductions in HbA1c levels were significantly greater with CSII (-1.1±1.2% [-12.0±13.1 mmol/mol]) than with MDI (-0.4±1.1% [-4.4±12.0 mmol/mol]) (P&lt;0.001). Similarly, compared with patients receiving MDI, those receiving CSII showed significantly greater reductions in 24-h mean sensor glucose (SG) (treatment difference, -17.1 mg/dL; P=0.0023), less exposure to SG &gt;180 mg/dL (-12.4%; P=0.0004) and SG &gt;250 mg/dL (-5.5%; P=0.0153), and more time in the SG range of 70-180 mg/dL (12.3%; P=0.0002), with no differences in exposure to SG&lt;70 mg/dL or in glucose variability. Changes in postprandial (4-h) glucose area under the curve &gt;180 mg/dL were significantly greater with CSII than with MDI after breakfast (-775.9±1,441.2 mg/dL/min vs. -160.7±1,074.1 mg/dL/min; P=0.0015) and after dinner (-731.4±1,580.7 mg/dL/min vs. -71.1±1,083.5 mg/dL/min; P=0.0014). Conclusions: In patients with suboptimally controlled type 2 diabetes, CSII significantly improves selected glucometrics, compared with MDI, without increasing the risk of hypoglycemia

Diagnostic accuracy of a clinical diagnosis of idiopathic pulmonary fibrosis: An international case-cohort study

We conducted an international study of idiopathic pulmonary fibrosis (IPF) diagnosis among a large group of physicians and compared their diagnostic performance to a panel of IPF experts. A total of 1141 respiratory physicians and 34 IPF experts participated. Participants evaluated 60 cases of interstitial lung disease (ILD) without interdisciplinary consultation. Diagnostic agreement was measured using the weighted kappa coefficient (\u3baw). Prognostic discrimination between IPF and other ILDs was used to validate diagnostic accuracy for first-choice diagnoses of IPF and were compared using the Cindex. A total of 404 physicians completed the study. Agreement for IPF diagnosis was higher among expert physicians (\u3baw=0.65, IQR 0.53-0.72, p20 years of experience (C-index=0.72, IQR 0.0-0.73, p=0.229) and non-university hospital physicians with more than 20 years of experience, attending weekly MDT meetings (C-index=0.72, IQR 0.70-0.72, p=0.052), did not differ significantly (p=0.229 and p=0.052 respectively) from the expert panel (C-index=0.74 IQR 0.72-0.75). Experienced respiratory physicians at university-based institutions diagnose IPF with similar prognostic accuracy to IPF experts. Regular MDT meeting attendance improves the prognostic accuracy of experienced non-university practitioners to levels achieved by IPF experts