Data Assimilation for a Geological Process Model Using the Ensemble Kalman Filter

We consider the problem of conditioning a geological process-based computer simulation, which produces basin models by simulating transport and deposition of sediments, to data. Emphasising uncertainty quantification, we frame this as a Bayesian inverse problem, and propose to characterize the posterior probability distribution of the geological quantities of interest by using a variant of the ensemble Kalman filter, an estimation method which linearly and sequentially conditions realisations of the system state to data. A test case involving synthetic data is used to assess the performance of the proposed estimation method, and to compare it with similar approaches. We further apply the method to a more realistic test case, involving real well data from the Colville foreland basin, North Slope, Alaska.Comment: 34 pages, 10 figures, 4 table

IDENTIFICATION OF PROBLEMATIC BEHAVIORS AMONG LEARNERS IN CLASSROOMS BY TEACHERS IN PRIMARY SCHOOLS SOUTH AFRICA

The study explored the identification of problematic behaviors of learners in the classroom by teachers in Midrand in the Gauteng province of South Africa. This study was informed by Bandura’s Social Cognitive theory. The multiple case study design was chosen for this study. The participants comprised fifteen teachers (15) who teach grade four in the three public primary schools in Midrand. This study employed semi-structured interviews for data collection. Thematic analysis was adopted to analyze the qualitative data.  The results of the study indicated that teachers identified the problem behaviors by observing learners in and out of class, observing disruptive behaviors, observing uncooperative learners, observing disobedience behaviors, and assessing learning difficulties. The study recommends that Life orientation teachers should teach learners to be aware of the practical skills that are required in times of crisis, when they are experiencing emotional stress, instead of acting out by displaying problem behavior

Diagnostic value of MRI of the sacroiliac joints in juvenile spondyloarthritis

Early diagnosis of spondyloarthritis (SpA) is becoming more important as new medical treatment options have become available to treat inflammation and delay progression of the disease. Increasingly, magnetic resonance imaging (MRI) of the sacroiliac joints is obtained for early detection of inflammatory changes, as it shows active inflammatory and structural lesions of sacroiliitis long before radiographic changes become evident. MRI of the sacroiliac joints in children is a useful tool for suspected juvenile spondyloarthritis (JSpA), even though it is not yet included in the current pediatric classification systems. Recognizing MRI features of pediatric sacroiliitis is a challenge. As most radiologists are not familiar with the normal MRI appearance of the pediatric sacroiliac joint, clear definitions are mandatory. Actually, the adult Assessment of Spondyloarthritis International Society (ASAS) definition for sacroiliitis needs some adaptations for children. A proposal for a possible pediatric-specific definition for active sacroiliitis on MRI is presented in this review. Furthermore, MRI without contrast administration is sufficient to identify bone marrow edema (BME), capsulitis, and retroarticular enthesitis as features of active sacroiliitis in JSpA. In selected cases, when high short tau inversion recovery (STIR) signal in the joint is the only finding, gadolinium-enhanced images may help to confirm the presence of synovitis. Lastly, we found a high correlation between pelvic enthesitis and sacroiliitis on MRI of the sacroiliac joints in children. As pelvic enthesitis indicates active inflammation, it may play a role in assessment of the inflammatory status. Therefore, it should be carefully sought and noted when examining MRI of the sacroiliac joints in children

Evolving morphotropic phase boundary in lead-free (Bi1/2Na1/2)TiO3–BaTiO3 piezoceramics

The correlation between structure and electrical properties of lead-free (1-x)(Bi(1/2)Na(1/2))TiO(3)-xBaTiO(3) (BNT-100xBT) polycrystalline piezoceramics was investigated systematically by in situ synchrotron diffraction technique, combined with electrical property characterization. It was found that the morphotropic phase boundary (MPB) between a rhombohedral and a tetragonal phase evolved into a morphotropic phase region with electric field. In the unpoled material, the MPB was positioned at the transition from space group R3m to P4mm (BNT-11BT) with optimized permittivity throughout a broad single-phase R3m composition regime. Upon poling, a range of compositions from BNT-6BT to BNT-11BT became two-phase mixture, and maximum piezoelectric coefficient was observed in BNT-7BT. It was shown that optimized electrical properties are related primarily to the capacity for domain texturing and not to phase coexistence

Intensive Archaeological Survey of the Proposed Casa Bella Estates Land Development Project and Data Recovery at Site 41BX2131, San Antonio, Bexar County, Texas

At the request of Matiraan, Ltd., Pape‐Dawson conducted an intensive archaeological survey with shovel testing and backhoe trenching of the proposed 37‐acre (15‐hectare [ha]) Casa Bella Estates residential development in compliance with the Historic Preservation and Design Section (Article 6 35‐360 to 35‐ 634) of the City of San Antonio (COSA) Unified Development Code (UDC). Based on the results of those investigations, the COSA Office of Historic Preservation (SA‐OHP) requested further work to mitigate the effects of the proposed development on a potentially significant archaeological site (41BX2131). Subsequently, data recovery investigations were accomplished at site 41BX2131. This report documents all phases of fieldwork. The Casa Bella Estates residential development is within the COSA city limits at the confluence of Mud and Elm Waterhole Creeks in northern Bexar County, about 1.40 miles (2.25 kilometers [km]) southwest of the intersection of Bulverde Road and Loop 1604. The irregularly shaped project area straddles an existing driveway that provides access to Jones Maltsberger Road. The development would be maximally about 1,739 feet (ft) (530 meters [m]) north to south, and 2,264 ft (690 m) east to west. The vertical impacts for the proposed development have not yet been determined. Compliance with the Antiquities Code of Texas or Section 106 of the National Historic Preservation Act is not required because the project is on private property and does not involve federal funding or permitting. However, based on the Archaeological Report Guidelines of the SA‐OHP, any observed cultural resources were to be evaluated according to the criteria in Title 36 Code of Federal Regulations Part 60.4 (36 CFR 60.4) and in Title 13 Texas Administrative Code Chapter 26.10 (13 TAC 26.10). The purpose of the investigations was to identify all historic or prehistoric cultural resources located within the project area and to evaluate the significance and eligibility of identified resources for inclusion to the National Register of Historic Places (NRHP) or for designation as a State Antiquities Landmark (SAL). All work was done in accordance with the archaeological survey standards and guidelines as developed by the Council of Texas Archaeologists (CTA) and adopted by the Texas Historical Commission (THC). The investigations included a cultural resources background literature and records review and an intensive survey with mechanical trenching, followed by data recovery mitigation. Fieldwork for the initial survey took place between October 9, and November 12, 2015. The entirety of the project area was subject to visual inspection supplemented by systematically placed shovel tests in order to evaluate the impact of the proposed project on cultural resources. A second phase of survey with backhoe trenching followed on November 11 and 12, 2015. Archaeologists excavated a total of 28 shovel tests and 6 backhoe trenches, exceeding the minimum CTA/THC archaeological survey standards, which require a ratio of 1 shovel test per 2 acres for a 37‐acre (15‐ha) project area. Pape‐Dawson archaeologists encountered cultural material in 23 shovel tests and 5 trenches throughout the project area as part of their survey efforts. Site 41BX2131 was evaluated according to the criteria in 36 CFR 60.4 and 13 TAC 26.10, and determined to be potentially eligible for inclusion to the NRHP and for designation as an SAL. Based on the results of the survey and subsequent coordination with COSA. Archaeologist Kay Hindes, Pape‐Dawson conducted data recovery mitigation for 41BX2131 because it could not be avoided by development. Data recovery took place on January 6 to 8, 2016, and involved the excavation of three additional backhoe trenches and two 1‐by‐1‐meter, hand‐excavated units. One diagnostic projectile point, a Frio, was encountered in an excavation unit, and radiocarbon dated to 903±37 B.P. (D‐AMS 016005) (2‐sigma calibrated age estimate of A.D. 1035 to 1211, with a median probability of A.D. 1119). The generally accepted time range for Frio points is within the Transitional Archaic period at 200 B.C. to A.D. 600 or later (Turner and Hester 1999:122); in this case, more than 500 years later. One other radiocarbon date from the same unit, but 12 inches (30 centimeters [cm]) below the projectile point, was 1090±32 B.P. (D‐AMS 016006) (2‐sigma calibrated age estimate of A.D. 892 to 1015, with a median probability of A.D. 953), demonstrating that the preserved occupation at site 41BX2131 is limited to a 166‐ to 319‐year interval during the transition between the Transitional Archaic and Late Prehistoric periods. No pottery or arrow points typical of the Late Prehistoric period were encountered at site 41BX2131; however, the radiocarbon results situate the site within the early portion of the Late Prehistoric period. The many tested cobbles and large flakes present on the surface indicate that initial reduction took place here. Several preforms and bifaces noted on the surface, and the small size of many tertiary flakes from the data recovery also suggest more detailed work occurred. The actual borders of the site were not discovered, as they extend beyond the project area. The site has likely been destroyed by the surrounding urban development and associated infrastructure construction. Disturbances within the project area include vehicle trails, a sewage line, artifacts taken from the surface by prior owners, and erosion near the drainages. Project records and photographs will be curated at the Center for Archaeological Studies (CAS) at Texas State University in San Marcos, while artifacts will be returned to the landowner. Based on the results of the investigations, intact archaeological deposits that maximally span than about 300 years of occupation were documented at the site, including faunal bone and charcoal in the assemblage. Pape‐ Dawson archaeologists recommend that site 41BX2131 is eligible for inclusion to the NRHP and for designation as an SAL. No further work is recommended, as site 41BX2131 was mitigated through detailed hand‐excavations. If human remains are encountered during construction, Pape‐Dawson recommends that all work in the immediate area should cease and the appropriate agencies be contacted for guidance

Prospects in the use of Ficus polita as a local ruminant feed

The proximate as well as the mineral compositions of Ficus polita and some anti nutritional factors were determined in order to justify the local use of this plant as a feedstuff especially for ruminant animals and to establish the possible wide scale utilization of this plant in the feed industry. The proximate, mineral and phytonutrient compositions of the plant were determined using standard methods of analysis. The plant was found to contain reasonable amounts of both macro and micro minerals required by farm animals for healthy growth. The caloric value of F. polita was also compatible with those of most tubers, roots and green leaves of many plant feeding stuffs. Also, the anti nutritional factors of the plant were found to be low. Thus, this plant, if well studied, could be used as an alternativeto the highly prized grains and legumes required in human nutrition

Caring for the older person with cognitive impairment in hospital: Qualitative analysis of nursing personnel reflections on fall events

Aims and objectives To explore nurse and nursing assistant reflections on the care of older patients with cognitive impairment who have experienced a fall. Background While there are evidence‐based clinical guidelines for the prevention and management of falls and for the care of older people with cognitive impairment, the falls rates for older people with cognitive impairment are three times as high as those without. Design Critical incident technique. Methods Eleven registered and two enrolled nurses and four assistants in nursing working in one subacute and two acute wards within two hospitals of a tertiary level health service in south‐east Queensland. Individual semistructured interviews focused on two past events when a patient with cognitive impairment had fallen in hospital: one when there was minimal harm and the second when there was significant harm. Thematic analysis was undertaken. The COREQ checklist was followed. Results Three themes emerged from 23 reflective accounts of fall events: “direct observation is confounded by multiple observers” and “knowing the person has cognitive impairment is not enough,” and “want to rely on the guideline but unsure how to enact it.” While participants were aware of the falls prevention policy and techniques available to prevent falls, the implementation of these was challenging due to the complexity of care required by the older person with cognitive impairment. Conclusions Falls prevention for older people with cognitive impairment is complex and belies the simple application of policy. Relevance to clinical practice To reduce falls, nurses can involve the family to support “knowing the patient” to enable prediction of impulsive actions; shift the focus of in‐service from lectures to specific case presentations, with collaborative analysis on person‐focused strategies to prevent falls in older people with cognitive impairment; and reconsider the sitter role from simple observer to assistant, focused on ambulation and supporting independence in activities of daily living.Full Tex

A revised implicit equal-weights particle filter

Particle filters are fully non-linear data assimilation methods and as such are highly relevant. While the standard particle filter degenerates for high-dimensional systems, recent developments have opened the way for new particle filters that can be used in such systems. The implicit equal-weights particle filter (IEWPF) is an efficient approach which avoids filter degeneracy because it gives equal particle weights by construction. The method uses implicit sampling whereby auxiliary vectors drawn from a proposal distribution undergo a transformation before they are added to each particle. In the original formulation of the IEWPF, the proposal distribution has a gap causing all but one particle to have an inaccessible region in state space. We show that this leads to a systematic bias in the predictions and we modify the proposal distribution to eliminate the gap. We achieved this by using a two-stage proposal method, where a single variance parameter is tuned to obtain adequate statistical coverage properties of the predictive distribution. We discuss properties of the implicit mapping from an auxiliary random vector to the state vector, keeping in mind the aim of avoiding particle resampling. The revised filter is tested on linear and weakly nonlinear dynamical models in low-dimensional and moderately high-dimensional settings, demonstrating the suiccess of the new methodology in removing the bias