Contamination of groundwater by petroleum hydrocarbons: Impact of fuel stations in residential areas

Anthropogenic factors such as leakages from fuel storage facilities contribute to the release of petroleum hydrocarbons into groundwater. Following the proliferation of fuel stations in residential areas, this research assessed physicochemical parameters, salinity, and levels of total petroleum hydrocarbons (TPH) in groundwater sources within selected residential areas. From the study, mean values of temperature (30.5 °C), pH (5.8), EC (181.5 μs/cm), TDS (90.7 mg/L), and salinity (0.1 ppm) were recorded. The highest mean concentration of TPH (9.5 mg/L) was recorded at location A, while three sampling points (J, L, and M) exhibited 0.0 mg/L. Notably, TPH concentrations exceeding permissible limits were observed at three sampling points (A, B, and R). Strong positive correlations were observed between EC and TDS (r = 0.9), as well as salinity and EC (r = 0.9) and TDS (r = 0.9). Matrix plots demonstrated non-linear relationships, except for TDS and EC, although TPH and temperature exhibited a slightly linear pattern. The distance from USTs to the groundwater sources varied in the area. At location H, this distance (25 m) was measured as the shortest, where the mean TPH concentration was 3.71 mg/L. However, site Q exhibited the longest distance of 535 m, accompanied by a mean TPH concentration of 1.1 mg/L. Though the proximity of USTs to groundwater sources exerted some level of influence on the groundwater system, multiple linear regression, ANOVA, and cluster analysis showed that this did not pose direct and major impacts on the concentrations of TPH. However, approaches are needed to remediate the affected groundwater sources.

Outside the limit: questioning the distance restrictions for cooperative miRNA binding sites

Among the concepts in biology that are widely taken granted is a potentiated cooperative effect of multiple miRNAs on the same target. This strong hypothesis contrasts insufficient experimental evidence. The quantity as well as the quality of required side constraints of cooperative binding remain largely hidden. For miR-21-5p and miR-155-5p, two commonly investigated regulators across diseases, we selected 15 joint target genes. These were chosen to represent various neighboring 3'UTR binding site constellations, partially exceeding the distance rules that have been established for over a decade. We identified different cooperative scenarios with the binding of one miRNA enhancing the binding effects of the other miRNA and vice versa. Using both, reporter assays and whole proteome analyses, we observed these cooperative miRNA effects for genes that bear 3'UTR binding sites at distances greater than the previously defined limits. Astonishingly, the experiments provide even stronger evidence for cooperative miRNA effects than originally postulated. In the light of these findings the definition of targetomes specified for single miRNAs need to be refined by a concept that acknowledges the cooperative effects of miRNAs.

Evaluating metrics in link streams

We seek to understand the topological and temporal nature of temporal networks by computing the distances, latencies and lengths of shortest fastest paths. Shortest fastest paths offer interesting insights about connectivity that were unknowable until recently. Moreover, distances and latencies tend to be computed by separate algorithms. We developed four algorithms that each compute all those values efficiently as a contribution to the literature. Two of those methods compute metrics from a fixed source temporal node. The other two, as a significant contribution to the literature, compute the metrics between all pairs of source and destination temporal nodes. The methods are also grouped by whether they work on paths with delays or not. Proofs of correctness for our algorithms are presented as well as bounds on their temporal complexities as functions of temporal network parameters. Experimental results show the algorithms presented perform well against the state of the art and terminate in decent time on real-world datasets. One purpose of this study is to help develop algorithms to compute centrality functions on temporal networks such as the betweenness centrality and the closeness centrality.

Review of Riemannian Distances and Divergences, Applied to SSVEP-based BCI

The firstgeneration of brain-computer interfaces (BCI) classifies multi-channel electroencephalographic (EEG) signals, enhanced by optimized spatial filters.The second generation directly classifies covariance matrices estimated on EEG signals, based on straightforward algorithms such as the minimum-distance-to-Riemannian-mean (MDRM). Classification results vary greatly depending on the chosen Riemannian distance or divergence, whose definitions and reference implementations are spread across a wide mathematical literature. This paper reviews all the Riemannian distances and divergences to process covariance matrices, with an implementation compatible with BCI constraints. The impact of using different metrics is assessed on a steady-state visually evoked potentials (SSVEP) dataset, evaluating centers of classes and classification accuracy. Riemannian approaches embed crucial properties to process EEG data. The Riemannian centers of classes outperform Euclidean ones both in offline and online setups. Some Riemannian distances and divergences have better performances in terms of classification accuracy, while others have appealing computational efficiency.

Computational techniques to segment and classify lumbar compression fractures

Vertebral fractures are important indicators of osteoporosis. Fractures with partial collapse of vertebral bodies are referred to as vertebral compression fractures (VCFs) that are usually non-traumatic in nature. Some common causes of VCFs are trauma, bone failure related to osteoporosis (benign) and metastatic cancer (malignant). This paper aims at developing a system for computer-aided diagnosis to help in the detection, labeling and segmentation of lumbar vertebral body (VB) and to further classify each VB into normal, malignant and benign VCFs. After the initial preprocessing, morphological, shape and angular features are used in the detection, labeling and segmentation steps. Various shape and statistical texture features are extracted from the segmented VB and are fed to the classifier for the final decision. The segmentation and classification results obtained were compared with the ground truth manual segmentation of the lumbar VB and the decision labels of the fractures provided by the experts. The dice similarity coefficient (DSC) for segmentation reached up to 94.27%, and the classification results show that shape and texture features together are able to correctly classify with an accuracy rate of 95.34%. The final outcomes are expected to be useful in the analysis of vertebral compression fractures.

EPR Techniques to Probe Insertion and Conformation of Spin-Labeled Proteins in Lipid Bilayers

Electron paramagnetic resonance (EPR) spectroscopy of spin-labeled membrane proteins is a valuable biophysical technique to study structural details and conformational transitions of proteins close to their physiological environment, for example, in liposomes, membrane bilayers, and nanodiscs. Unlike in nuclear magnetic resonance (NMR) spectroscopy, having only one or few specific side chains labeled at a time with paramagnetic probes makes the size of the object under investigation irrelevant in terms of technique sensitivity. As a drawback, extensive site-directed mutagenesis is required in order to analyze the properties of the protein under investigation. EPR can provide detailed information on side chain dynamics of large membrane proteins or protein complexes embedded in membranes with an exquisite sensitivity for flexible regions and on water accessibility profiles across the membrane bilayer. Moreover, distances between the two spin-labeled side chains in membrane proteins can be detected with high precision at cryogenic temperatures. The application of EPR to membrane proteins still presents some challenges in terms of sample preparation, sensitivity and data interpretation, thus it is difficult to give ready-to-go methodological recipes. However, new technological developments (arbitrary waveform generators) and new spin labels spectroscopically orthogonal to nitroxides increased the range of applicability from in vitro toward in-cell EPR experiments. This chapter is an updated version of the one published in the first edition of the book and describes the state of the art in the application of nitroxide-based site-directed spin labeling EPR to membrane proteins, addressing new tools such as arbitrary waveform generators and spectroscopically orthogonal labels, such as Gd(III)-based labels. We will present challenges in sample preparation and data analysis for functional and structural membrane protein studies using site-directed spin labeling techniques and give experimental details on EPR techniques providing information on side chain dynamics and water accessibility using nitroxide probes. An updated optimal Q-band DEER setup for nitroxide probes will be described, and its extension to gadolinium-containing samples will be addressed.

Injuries sustained in falling fatalities in relation to different distances of falls

BACKGROUND

Falling from a distance is an important issue worldwide, which happens in different ages, genders and circumstances. It is usually not considered a medicolegal case in many countries hence no autopsy is performed. This study focused on analyzing injuries sustained in victims of falling in relation to different distances of fall.

METHODS

Retrospective study of 352 autopsy reports of falling victims brought to the forensic pathology department at Jordan University Hospital during the period from January 1990 to March 2016.

RESULTS

Among 352 cases, 256 (72.7%) were males and 96 (27.3%) were females. 303 (86.1%) cases showed accidental fall, 31 (8.8%) were suicidal, 2 (0.6%) were homicidal and un-clarified death in 16 (4.5%). Time of death was directly proportionate with the distance of fall. Victims fell from distances less than 3 m were 123 (35%), most of them were children less than 7 years 50 (40.5%) and unemployed adults more than 45 years were 48 (39.1%). They showed multiple abrasions (62.6%), few contusions (64.2%) and absent laceration of the skin (84.5%). Victims fell from distances of 3-9 m were 123 (35%), most of them were male workers 56 (60.2%). They showed multiple abrasions (63.5%), few contusions (71%) and few lacerations of skin (50.5%). Victims fell from distances more than 9 m were 136 (38.6%), most of them were male workers 71 (52.2%) and female servants 23 (17%). They showed few abrasions (80.9%), multiple contusions (64.7%) and few lacerations of skin (48.5%). The number of fractured limbs increases obviously with distances more than 3 m. Skull vault fractures were found in all distances, while skull base fractures showed in distances of 3-9 m and more than 9 m. Head injury was the most common fatal injury in all distances. Chest injuries were prominent mainly in distances more than 3 m. While abdominal injuries were mainly prominent in distances more than 9 m.

CONCLUSIONS

This study showed the effect of different distances of fall in causing different types of injuries in falling fatalities. Internal injuries were in a direct proportion with distances of fall, while external injuries showed a great importance in interpretation of the way of fall.

Distances between bony landmarks and adjacent nerves: anatomical factors that may influence retractor placement in total hip replacement surgery

Background

Retractor placement is a leading cause of intraoperative nerve injury during total hip replacement (THR) surgery. The sciatic nerve, femoral nerve, and superior gluteal nerve are most commonly affected. This study aimed to identify the distances from bony landmarks in the hip to the adjacent nerves on magnetic resonance imaging (MRI) and the associations between anatomical factors and these distances that would guide the placement of retractors during THR surgery, in order to minimize the risk of nerve injury.

Methods

We reviewed hip MRIs of 263 adults and recorded the distances from (1) the anterior acetabular rim to the femoral nerve; (2) the superior acetabular rim to the superior gluteal nerve; (3) the posterior acetabular rim to the sciatic nerve; and (4) the greater trochanter to the sciatic nerve. The effects of anatomical factors (i.e., gender, age, body height, body mass index (BMI), pelvic width, and acetabular version and morphology) on these distances were analyzed.

Results

Distances from bony landmarks to adjacent nerves (in cm) were 2.06 ± 0.44, 2.23 ± 0.28, 1.94 ± 0.81, and 4.83 ± 0.26 for the anterior acetabular rim, superior acetabular rim, posterior acetabular rim, and greater trochanter, respectively, and were shorter in women than in men (P < 0.001). Multivariate analysis identified body height as the most influential factor (P < 0.001). Linear regression demonstrated a strong positive linear correlation between body height and these distances (Pearson’s r = 0.808, 0.823, 0.818, and 0.792, respectively (P < 0.001)).

Conclusions

The distances from bony landmarks to adjacent nerves provide useful information for placing retractors without causing nerve injury during THR surgery. Shorter patients will have shorter distances from bony landmarks to adjacent nerves, prompting more careful placement of retractors.

Accurate NMR determination of C-H or N-H distances for unlabeled molecules

Cross-Polarization with Variable Contact-time (CP-VC) is very efficient at ultra-fast MAS (νR ≥ 60 kHz) to measure accurately the dipolar interactions corresponding to C-H or N-H short distances, which are very useful for resonance assignment and for analysis of dynamics. Here, we demonstrate the CP-VC experiment with (1)H detection. In the case of C-H distances, we compare the CP-VC signals with direct ((13)C) and indirect ((1)H) detection and find that the latter allows a S/N gain of ca. 2.5, which means a gain of ca. 6 in experimental time. The main powerful characteristics of CP-VC methods are related to the ultra-fast spinning speed and to the fact that most of the time only the value of the dipolar peak separation has to be used to obtain the information. As a result, CP-VC methods are: (i) easy to set up and to use, and robust with respect to (ii) rf-inhomogeneity thus allowing the use of full rotor samples, (iii) rf mismatch, and (iv) offsets and chemical shift anisotropies. It must be noted that the CP-VC 2D method with indirect (1)H detection requires the proton resolution and is thus mainly applicable to small or perdeuterated molecules. We also show that an analysis of the dynamics can even be performed, with a reasonable experimental time, on unlabeled samples with (13)C or even (15)N natural abundance.

Managing different forms of distances in Dutch healthcare organizations: The relation between managers and professionals as a dynamic continuum of distance and proximity

PURPOSE

Dichotomous "gap" thinking about professionals and managers has important limits. The purpose of this paper is to study the specific ontology of "the gap" in which different forms of distances are defined.

DESIGN/METHODOLOGY/APPROACH

In order to deepen the knowledge of the actual day-to-day tasks of Dutch healthcare executives an ethnographic study of the daily work of Dutch healthcare executives and an ontological exploration of the concept "gap" was provided. The study empirically investigates the meaning given to the concept of "distance" in healthcare governance practices.

FINDINGS

The study reveals that healthcare executives have to fulfil a dual role of maintaining distance and creating proximity. Coping with different forms of distances seems to be an integral part of their work. They make use of four potential mechanisms to cope with distance in their healthcare organization practices.

ORIGINALITY/VALUE

The relationship between managers and professionals is often defined as a dichotomous gap. The findings in this research suggest a more dynamic picture of the relationship between managers and professionals than is currently present in literature. This study moves "beyond" the gap and investigates processes of distancing in-depth.