The effect of slope steepness and antecedent moisture content on interrill erosion, runoff and sediment size distribution in the highlands of Ethiopia

Soil erosion is a two-phase process consisting of the detachment of individual particles and their transport by the flowing water. This study discusses the results of laboratory experiments in which for three soils, the runoff depth, sediment yield, splash erosion and sediment size were measured. Rainfall intensity, slope and antecedent moisture contents were varied in the experiment. The soil types ranged from clay to sandy clay loam (Alemaya Black soil, Regosols and Cambisols). Rainfall was applied for six sequential 15-min periods with rainfall intensities varying between 55 and 120 mm h<sup>−1</sup>. The three slopes tested were 9, 25, and 45 %. Results show that as slope increased from 9 to 25 %, splash erosion and sediment yield increased. An increase in slope from 25 to 45 % generally decreases in splash erosion. Sediment yield for one soil increased and one soil decreased with slope and for the third soil the trend was different between the two initial moisture contents. Sediment yield was correlated (<i>r</i> = 0.66) with runoff amounts but not with splash erosion. Interrill erosion models that were based on the flowing water and rainfall intensity fitted the data better than when based on rainfall intensity solely. Models that assume a positive linear relationship between erosion and slope may overestimate sediment yield

Coherent Error Suppression in Multi-Qubit Entangling Gates

We demonstrate a simple pulse shaping technique designed to improve the fidelity of spin-dependent force operations commonly used to implement entangling gates in trapped-ion systems. This extension of the M{\o}lmer-S{\o}rensen gate can theoretically suppress the effects of certain frequency and timing errors to any desired order and is demonstrated through Walsh modulation of a two-qubit entangling gate on trapped atomic ions. The technique is applicable to any system of qubits coupled through collective harmonic oscillator modes

Entanglement of Atomic Qubits using an Optical Frequency Comb

We demonstrate the use of an optical frequency comb to coherently control and entangle atomic qubits. A train of off-resonant ultrafast laser pulses is used to efficiently and coherently transfer population between electronic and vibrational states of trapped atomic ions and implement an entangling quantum logic gate with high fidelity. This technique can be extended to the high field regime where operations can be performed faster than the trap frequency. This general approach can be applied to more complex quantum systems, such as large collections of interacting atoms or molecules.Comment: 4 pages, 5 figure

ISOLATION AND IDENTIFICATION OF BIOFILM PRODUCING ENTEROCOCCUS FAECALIS FROM ROOT CANAL

This study was aimed to one of the most prevalent causes for endodontic treatment failure is the presence of Enterococcus faecalis bacterium within teeth root canals. To achieve successful treatment, it is so important to study E. faecalis behavior. The aim of study was to investigate biofilm production and antibiotic sensitivity of E. faecalis isolated from root canals. Results showed isolation of E. feacalis (65%) of samples, identified by specific gene by PCR technique. Most isolates were sensitive to Imipenem and resistant to Erythromycin, Clindamycin, Tetracycline and Trimethoprim. Strong biofilm production was detected among 29.5% of highest antibiotic resistant isolates. The results may indicate that infected root canals with E. feacalis may lead to serious complication for patients

Prostate Cancer Incidence Rates in Africa

African American men have among the highest prostate cancer incidence rates in the world yet rates among their African counterparts are unclear. In this paper, we compared reported rates among black men of Sub-Saharan African descent using data from the International Agency for Research on Cancer (IARC) and the National Cancer Institute Surveillance, Epidemiology, and End Results Program for 1973–2007. Although population-based data in Africa are quite limited, the available data from IARC showed that rates among blacks were highest in the East (10.7–38.1 per 100,000 man-years, age-adjusted world standard) and lowest in the West (4.7–19.8). These rates were considerably lower than those of 80.0–195.3 observed among African Americans. Rates in Africa increased over time (1987–2002) and have been comparable to those for distant stage in African Americans. These patterns are likely due to differences between African and African American men in medical care access, screening, registry quality, genetic diversity, and Westernization. Incidence rates in Africa will likely continue to rise with improving economies and increasing Westernization, warranting the need for more high-quality population-based registration to monitor cancer incidence in Africa

STRESS SENSITIVITY OF SATURATION AND END-POINT RELATIVE PERMEABILITIES

ABSTRACT Production induced changes in stress due to reductions in pore pressure have the potential to alter the flow properties of reservoir rocks. There are a large number of experimental results, which show that single-phase permeability is a function of applied stress. In hydrocarbon reservoirs two or even three phases may flow simultaneously through the pore network, however very little data exists on the stress sensitivity of multiphase flow. To measure the stress sensitivity of two-phase flow, the relative permeability of a sandstone was measured as a function of applied stress. The sandstone was an aeolean sandstone from a surface deposit. The sandstone was strongly water wet with an AmottHarvey index of 0.91. The porosity of the samples were between 25.4 and 28.0% and the Klinkenberg corrected gas permeability between 1051 and 1644mD. Samples were saturated with brine under high pressure, flooded with oil at different stresses to an equilibrium initial water saturation, then waterflooded to residual oil saturation. The average water saturation or oil saturation in the sample was calculated from the volume of brine or oil produced. The initial water saturation was stress sensitive in all cores tested. During the dynamic desaturation of a sample at a given stress equilibrium water saturation was reached between 2 and 8 pore volumes of injected oil. The stress was then increased and a new equilibrium water saturation reached. At an injection rate of 40ml/hr water saturations of approximately 0.400 were achieved at 400psi, this dropped to 0.385 at 3000psi and 0.377 at 8000psi. The variation of water saturation with stress can be qualitatively explained in terms of the changing pore volume and the balance between capillary and viscous forces. At a given stress and injection rate there is a balance between the capillary and viscous forces in the pores. The flowing oil is excluded from pores below a certain size by capillary forces. When the stress is increased the entire pore network deforms. Brine is squeezed out of small brine filled pores into the larger pores, where it is swept out of the sample. The effective permeability end points k o (S wi ) and k w (S or ) were stress sensitive, more so than the single phase permeability. A 15% drop in k o (S wi ) was noted from 400-3000psi. This compares to an 8% drop in the single-phase permeability of this material. This shows that the end point relative permeabilities were also stress sensitive

Does surgical site infection influence neurological outcome and survival in patients undergoing surgery for metastatic spinal cord compression?

Purpose: Most of the literature on infection after surgery for spinal metastases focuses on incidence and risk factors for surgical site infection (SSI). To the best of our knowledge, there is no report on the influence of infection on neurological outcome and survival in patients undergoing emergent surgery for metastatic spinal cord compression (MSCC).Methods: Our aim was to establish if SSIs adversely affected the neurological outcome and survival in patients with MSCC. We reviewed 318 consecutive patients admitted for surgical intervention for MSCC from October 2005 to October 2012. Morbidity (neurological outcome, length of hospital stay and additional procedures) and survival rates were analysed.Results: During this study period, the incidence of infection was 29/318 (9.1%). The median length of stay in hospital in the infected group was 25 days compared to 13 days in the non-infected group (p = 0.001). Twenty out of the 29 (69%) infected patients underwent an additional procedure (29 procedures in total) compared to 9/289 (3%) non-infected patients (p = 0.001). There was no statistical difference between the two groups with regard to neurological outcome (p = 0.37) but the survival rate was statistically different between the two groups [infected group: median survival 131 days (19–1558) vs. non-infected group: 258 days (5–2696; p = 0.03)].Conclusion: Surgical site infection increased the morbidity with considerably longer hospital stay and requirement for additionalprocedures. Although there was no difference in neurological outcome, the infected group of patients had a significantlyshorter survival

Study of the Acute Stress Effects on Decision Making Using Electroencephalography and Functional Near-Infrared Spectroscopy: A Systematic Review

This systematic review provides a comprehensive analysis of studies that use electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) to investigate how acute stress affects decision-making processes. The primary goal of this systematic review was to examine the influence of acute stress on decision making in challenging or stressful situations. Furthermore, we aimed to identify the specific brain regions affected by acute stress and explore the feature extraction and classification methods employed to enhance the detection of decision making under pressure. Five academic databases were carefully searched and 27 papers that satisfied the inclusion criteria were found. Overall, the results indicate the potential utility of EEG and fNIRS as techniques for identifying acute stress during decision-making and for gaining knowledge about the brain mechanisms underlying stress reactions. However, the varied methods employed in these studies and the small sample sizes highlight the need for additional studies to develop more standardized approaches for acute stress effects in decision-making tasks. The implications of the findings for the development of stress induction and technology in the decision-making process are also explained

Effect of Interruptions and Cognitive Demand on Mental Workload: A Critical Review

Worker safety and productivity are crucial for effective job management. Interruptions to an individual’s work environment and their impact on mental health can have adverse effects. One prospective instrument for assessing and calculating an individual’s mental state in an interrupted scenario and cognitive demand levels is the use of physiological computing devices in conjunction with behavioral and subjective measurements. This study sought to address how to gather and compute data on individuals’ cognitive states in interrupted work settings through critical analysis. Thirty-three papers were considered after the literature search and selection procedure. This descriptive study is conducted from three perspectives: parameter measurement, research design, and data analysis. The variables evaluated were working memory, stress, emotional state, performance, and resumption lag. The subject recruitment, experimental task design, and measurement techniques were examined from the standpoint of the experimental design. Data analysis included computing and cognitive pre-processing. Four future research directions are suggested to address the shortcomings of the present studies. This study offers suggestions for researchers on experiment planning and using computing to analyze individuals’ cognitive states during interrupted work scenarios. Additionally, it offers helpful recommendations for organizing and conducting future research