The Case of the Unidentified Energy Companies

This case provides detailed financial information for 14 firms in the energy sector across different fields. The student is put in the position of a potential job candidate tasked with identifying the field in which a firm’s major operations lie. The student’s objective is to use existing knowledge of the energy sector or financial statements to differentiate between the firms by examining the financial statements and common financial ratios for each of the firms

Forearm arterial distensibility in systolic hypertension

It is unclear whether the stiffened arterial tree in systolic hypertension is the cause or the effect of the disease. In this study, brachial and radial arterial pulses were sensed by external Pixie transducers and measurements of pulse wave velocity converted to volume distensibility using the Bramwell-Hill equation. Blood pressure was controlled as a variable by repeating the measurements at a variety of transmural arterial pressures. This was accomplished by encasing the forearm in a rigid plastic cylinder within which pressures were varied.Twenty-nine patients with systolic hypertension were compared with 22 age-matched control subjects. At ambient pressures the volume distensibility of patients was lower than that of control subjects (0.10 versus 0.18% Δ volume/mm Hg, p < 0.001) but there was no difference in volume distensibility between the two groups at any comparable transmural pressure. Nineteen patients were treated for 1 month with a thiazide diuretic agent and the studies were then repeated. Systolic and diastolic blood pressure decreased significantly and volume distensibility increased (0.10 to 0.15% Δ volume/mm Hg, p < 0.001) at ambient pressures. But at comparable transmural pressures, volume distensibility was unchanged.It is concluded that, in the forearm, increased arterial stiffness is the result and not the cause of systolic hypertension, but these data cannot exclude increased aortic stiffness as a significant factor. Thiazide diuretic drugs increase forearm arterial compliance by lowering blood pressure without a demonstrable drug effect on this arterial wall

Alterations in the mechanism of haemostasis in the post-surgical patient associated with the development of a hypercoagulable state

Sequential testing, using a wide spectrum of clotting tests, most of which were designed for this study, was performed on dilute whole blood samples obtained from a series of 25 patients who underwent a variety of major elective surgical procedures. Testing commenced prior to surgery and thereafter at intervals during the first 7 to 10 days postoperatively. Clotting test results were compared to the pre-operative mean values so that each patient acted as his own control. -- Very shortly after surgery, increased in vitro coagulability was demonstrated in almost all patients by the use of the phase 1, phase 2, heparin resistance, autocoagulography and autocoagulography control tests. A peak increase in coagulability was found between days 3 to 5, with a smaller peak occurring on or around the eight day postoperative. The results of the phase 3 test showed marked dispersion in some patients, while others gave results consistent with increased coagulability. -- Plasma fibrinogen concentration and the platelet count both increased early in the postoperative period and thereafter increased progressively. The results of the two universally used tests of haemostasis, namely the prothrombin time and the kaolin-cephalin clotting time were comparatively poor indicators of the postoperative increase in coagulability demonstrated by the phase 1, phase 2, heparin resistance, autocoagulography and autocoagulography control tests, although the results of the phase 3 test were somewhat similar to those found using the prothrombin time. -- This study has demonstrated that in the majority of patients a postoperative increase in the concentration of serum fibrin(ogen) degradation products is found at some time during the first 7 days following surgery. -- Clot retraction, studied with an original technique, was found to increase in approximately 50% of patients during the first 3 postoperative days. -- During the first 7 days following major elective surgery, the rise in the fibrinogen concentration and in the platelet count, and the increase in the concentration of serum fibrin(ogen) degradation products indicates that, in attempting to detect haemostatic failure in the postoperative patient, evaluation of haemostatic tests should not be made using the so-called "normal values". The author suggests that postoperative evaluation of haemostasis be compared to values obtained prior to surgery

Allometry of sodium requirements and mineral lick use among herbivorous mammals

Sodium (Na) plays a critical role in the functioning of terrestrial ecosystems. In Na-poor regions, plant consumers may experience Na deficiency and adapt by seeking supplementary Na resources. This can markedly impact animal behavior, space-use, and co-existence, with concomitant impacts on ecosystems. Many studies have noted that Na-seeking behaviors, such as soil consumption from mineral licks, are predominately observed for larger-bodied herbivores. However, the mechanisms that drive interspecific variation in Na deficiency and mineral lick use remain poorly understood. Here, we examine whether allometric scaling of Na requirements can explain variation in mineral lick use by herbivorous and omnivorous mammals. We 1) collated data from published literature to derive an allometric scaling of Na requirements in mammals, 2) compared predicted Na requirements to estimated Na intake of mammal communities in three globally distant sites: the Peruvian Amazon, Kalahari Desert, and Malaysian Borneo and 3) examined the relationship between predicted Na deficiency and mineral lick use utilizing camera-trap and mammal abundance data at each site. We found that minimum daily Na maintenance requirements in mammals scaled allometrically at a higher factor (BM0.91 (CI: 0.80–1.0)) than that of food and water Na intake (BM0.71–0.79), indicating that larger species may be more susceptible to Na limitation. This aligned with a positive association between mineral lick use and body mass (BM), as well as Na deficiency, by species at all sites, and increased artificial salt and mineral lick consumption by larger-bodied mammals in the Kalahari. Our results suggest that larger herbivores may be more sensitive to anthropogenic impacts to Na availability, which may alter their functional roles in ecosystems, particularly in Na-poor regions. Further research is needed to explore the consequences of changing Na availability on animals and ecosystems, as well as advance our understanding of Na physiology in mammals

Holography with Schroedinger Potentials

We examine the analogue one-dimensional quantum mechanics problem associated with bulk scalars and fermions in a slice of AdS_5. The ``Schroedinger'' potential can take on different qualitative shapes depending on the values of the mass parameters in the bulk theory. Several interesting correlations between the shape of the Schroedinger potential and the holographic theory exist. We show that the quantum mechanical picture is a useful guide to the holographic theory by examining applications from phenomenology.Comment: 22 pages, 4 figure

Diversity in the structures and ligand binding sites of nematode fatty acid and retinol binding proteins revealed by Na-FAR-1 from Necator americanus

Fatty acid and retinol binding proteins (FARs) comprise a family of unusual α-helix rich lipid binding proteins found exclusively in nematodes. They are secreted into host tissues by parasites of plants, animals and humans. The structure of a FAR protein from the free-living nematode Caenorhabditis elegans is available, but this protein (Ce-FAR-7) is from a subfamily of FARs that does not appear to be important at the host-parasite interface. We have therefore examined Na-FAR-1 from the blood-feeding intestinal parasite of humans, Necator americanus . The three dimensional structure of Na-FAR-1 in its ligand-free and ligand-bound forms, determined by nuclear magnetic resonance spectroscopy (NMR) and X-ray crystallography, respectively, reveals an a-helical fold similar to Ce-FAR-7, but Na-FAR-1 possesses a larger and more complex internal ligand binding cavity and an additional C-terminal a-helix. Titration of apo -Na-FAR-1 with oleic acid, analysed by NMR chemical shift perturbation, reveals that at least four distinct protein:ligand complexes can be formed. Na-FAR-1, and possibly other FARs, may have a wider repertoire for hydrophobic ligand binding, as confirmed here by our finding that a range of neutral and polar lipids co-purify with the bacterial recombinant protein. Finally, we show by immunohistochemistry that Na-FAR-1 is present in adult worms with a tissue distribution indicative of possible roles in nutrient acquisition by the parasite and in reproduction in the male

On the Geometric Interpretation of N = 2 Superconformal Theories

We clarify certain important issues relevant for the geometric interpretation of a large class of N = 2 superconformal theories. By fully exploiting the phase structure of these theories (discovered in earlier works) we are able to clearly identify their geometric content. One application is to present a simple and natural resolution to the question of what constitutes the mirror of a rigid Calabi-Yau manifold. We also discuss some other models with unusual phase diagrams that highlight some subtle features regarding the geometric content of conformal theories.Comment: 25 pages, note adde

Expression of miR-200c corresponds with increased reactive oxygen species and hypoxia markers after transient focal ischemia in mice

Embolic stroke results in a necrotic core of cells destined to die, but also a peri-ischemic, watershed penumbral region of potentially salvageable brain tissue. Approaches to effectively differentiate between the ischemic and peri-ischemic zones is critical for novel therapeutic discovery to improve outcomes in survivors of stroke. MicroRNAs are a class of small non-coding RNAs regulating gene translation that have region- and cell-specific expression and responses to ischemia. We have previously reported that global inhibition of cerebral microRNA200c after experimental stroke in mice is protective, however delineating the post-stroke sub-regional and celltype specific patterns of post-stroke miR-200c expression are necessary to minimize off-target effects and advance translational application. Here, we detail a novel protocol to visualize regional miR-200c expression after experimental stroke, complexed with visualization of regional ischemia and markers of oxidative stress in an experimental stroke model in mice. In the present study we demonstrate that the fluorescent hypoxia indicator pimonidazole hydrochloride, the reactive-oxygen-species marker 8-hydroxy-deoxyguanosine, neuronal marker MAP2 and NeuN, and the reactive astrocyte marker GFAP can be effectively complexed to determine regional differences in ischemic injury as early as 30 min post-reperfusion after experimental stroke, and can be effectively used to distinguish ischemic core from surrounding penumbral and unaffected regions for targeted therapy. This multi-dimensional post-stroke immunofluorescent imaging protocol enables a greater degree of subregional mechanistic investigation, with the ultimate goal of developing more effective post-stroke pharmaceutical therapy.Peer reviewe

Lymphocyte Trafficking in Psoriasis: A New Perspective Emphasizing the Dermal Dendrocyte with Active Dermal Recruitment Mediated Via Endothelial Cells Followed by Intra-Epidermal T-Cell Activation

Prominent within the inflammatory infiltrate of psoriasis are HLA-DR positive T lymphocytes and factor XIIIa positive dermal dendrocytes. Many investigators studying psoriasis have assumed that the HLA-DR positive T cells are activated, and thereby capable of producing lymphokines such as gamma interferon. However, by immunohistochemical analysis, greater than 95% of the dermal T cells in psoriatic lesions are Ki-67 negative, which suggests that they are in a resting or non-cycling (Go) state. In contrast to the darmal T-cell population, the epidermal T-cell population contains a greater population of Ki-67 positive lymphocytes. The entry of the T cells into the epidermis is, therefore, apparently associated with an important activation event, which in all likelihood involves interaction with the keratinocyte. The presence of activated intraepidermal T cells has been substantiated by the ability to detect gamma interferon mRNA by polymerase chain reaction in epidermal sheets of psoriatic lesions. The pathophysiologic implication in psoriasis for these distinctions and compartmentalization involving dermal and epidermal T cells are placed into the context of a cascade of cellular trafficking events, which are further dissected into a specific network of molecular mediators of inflammation. This report suggests that more attention should be placed on the microenvironment of the skin, with specific emphasis on the mechanism by which T cells accumulate in the dermis and epidermis, and elucidation of the selective inductive and recruitment capabilities of endothelial cells, perivascular dermal dendrocytes, and keratinocytes