cssi/SciSciGPT-SciSciNet huggingface dataset:
The duplex DNA is very underwound in the three-stranded RecA protein-mediated synaptic complex

Background: The RecA protein is a central player in bacterial homologous recombination. It promotes two key events: the search for homology between two DNA molecules and the subsequent formation of the synaptic complex composed of RecA and three DNA strands (two from one duplex and one single strand). In spite of numerous studies, the architecture of the synaptic complex is still far from clear. Results: We have exploited two approaches to study the structure of Escherichia coli RecA protein-mediated DNA synapsis: chemical modification with potassium permanganate and treatment of synaptic complexes of different lengths with topoisomerase I. The linking number difference values, obtained after separation of the individual sets of topoisomers in an agarose gel, were used to determine the number of bases per helical turn. We were able to show that the topology of the three-stranded complexes containing RecA is quite different from that expected for deproteinized D-loops. The original duplex in the synaptic complex is unwound, but not necessarily unpaired, to a structure topologically equivalent to DNA with approximately 27 bp per turn. Despite the fact that the patterns of reactivity towards potassium permanganate cannot be interpreted unambiguously, the results of chemical footprinting can be explained in terms of a synaptic complex as an extended and unwound three-stranded helical structure. Conclusions: This work provides the first quantitative topological parameters for the RecA protein-mediated three-stranded synaptic complex. Furthermore, the structure of synaptic complexes is different from that of a simple D-loop.
Chemical and ultrastructural identification of 5-hydroxytryptamine in an identified neuron.

The two largest cells in a typical ganglion of the leech (Hirudo medicinalis) nervous system are the colossal cells of Retzius. These cells show a positive chromaffin reaction, and it has been suggested that they contain 5-hydroxytryptamine (5-HT). In this study, the presence of 5-HT in the colossal cells was confirmed by microspectrofluorometry and by thin-layer chromatography and spectrofluorometry of extracts of individually dissected and pooled colossal cell bodies. A single colossal cell body was found to contain, on the average, 3.8 x 10-10 g (6mM) 5-HT. Electron microscopy shows that the colossal cells are distinguished by the presence of 1000 A granules with irregular, electron-opaque cores. Since the granules are distributed in the same pattern as the 5-HT fluorescence, we have suggested that they contain 5-HT. Furthermore, a chromaffin reaction modified for the electron microscope provides evidence that 5-HT is present in the granule cores. These data can now serve as a basis for further studies on the metabolism, distribution, and function of 5-HT in these identified neurons.
Finite Element Analysis of Alternating Phase-Shift Masks Subjected to Dynamic Pressure Loading Due to Megasonic Cleaning

The mechanical response of alternating phase-shift mask (APSM) microstructures to dynamic pressure loading during megasonic cleaning was analyzed with the finite element method (FEM). A parametric study of the effects of microstructure dimensions, pressure amplitude, and loading frequency on the mask structural integrity was performed for two typical chromium/quartz APSM patterns. Damage due to microfracture and plastic deformation processes encountered during megasonic cleaning was examined for frequencies of 1, 5, and 10 MHz. FEM results provide insight into possible damage modes and critical microstructure dimensions for catastrophic failure. Damage scenarios revealed by FEM results are in qualitative agreement with experimental observations. The results of this study have direct implications in the design of extreme ultraviolet lithography masks and the optimization of the megasonic cleaning process.
Effects of regional hypercalcemia on gastric acid secretion.

Abstract The effect of regional hypercalcemia on histamine-induced gastric acid secretion from chambered fundic segments was studied in five anesthetized mongrel dogs. This preparation allowed direct infusion of calcium into the nutrient artery of the gastric segment whereby venous effluent calcium levels were maintained in excess of 14 mg%, while systemic calcium levels were within a normal range. Blood flow, as measured by a venous effluent technique, did not change. Acid secretion decreased from 43.03 ± 7.13 to 12.20 ± 5.72 μEq/min during calcium infusion and rose to 37.04 ± 3.83 μEq/min when the infusion was terminated. These results provide clear evidence that calcium has a direct and reversible inhibitory effect on histamine-induced parietal cell secretion from exteriorized fundic segments of dog stomach.
Pigmented villonodular synovitis: MR imaging in pediatric patients.

Objectives: To describe the usefulness of gradient-echo imaging and contrast-enhanced MR imaging in diagnosing and assessing the extent of pigmented villonodular synovitis (PVNS) in pediatric patients. Patients and methods : Retrospective analysis of five pediatric patients (median age 14 years) with PVNS of the knee examined with a 1.5-T unit. Signal characteristics were obtained comparing T1- and proton-density (PD)-weighted imaging with gradient-echo imaging and enhanced imaging. The extent of the disease was assessed using the arthroscopic approach. Signal intensity ratios were statistically analyzed. Results: Compared to PD- and T1-weighted imaging sequences, gradient-echo imaging provides superior depiction of the extent of the disease due to signal decay (T2*-effect) of hemosiderin-laden thickened synovium and masses. Inflamed synovium with low hemosiderin deposition was identified on enhanced imaging. Beside the suprapatellar bursa and Hoffa’s fat pad, the area posterior to the cruciate ligaments is commonly involved. No bony abnormalities were present. Conclusion: Gradient-echo imaging together with enhanced imaging is useful in diagnosing and assessing the extent of PVNS in pediatric patients. A low signal mass behind the cruciate ligaments may represent an important diagnostic feature. Bony abnormalities were always absent.
Haematopoietic stem cells retain long-term repopulating activity and multipotency in the absence of stem-cell leukaemia SCL/ tal-1 gene

The production of blood cells is sustained throughout the lifetime of an individual by haematopoietic stem cells (HSCs). Specification of HSCs from mesoderm during embryonic development requires the stem cell leukaemia SCL/tal-1 gene product. Forced expression of SCL/tal-1 strongly induces blood formation in embryos, indicating that this gene has a dominant role in commitment to haematopoiesis. In the adult haematopoietic system, expression of SCL/tal-1 is enriched in HSCs and multipotent progenitors, and in erythroid and megakaryocytic lineages, consistent with roles for this factor in adult haematopoiesis. Here we assess by conditional gene targeting whether SCL/tal-1 is required continuously for the identity and function of HSCs. We find that SCL/tal-1 is dispensable for HSC engraftment, self-renewal and differentiation into myeloid and lymphoid lineages; however, the proper differentiation of erythroid and megakaryocytic precursors is dependent on SCL/tal-1. Thus, SCL/tal-1 is essential for the genesis of HSCs, but its continued expression is not essential for HSC functions. These findings contrast with lineage choice mechanisms, in which the identity of haematopoietic lineages requires continuous transcription factor expression.
Origin of Pennsylvanian Underclays in the Illinois Basin

Experimental evidence suggests the detrital origin of underclays of the Illinois Basin. Flocculated clay materials were deposited in glass tubes and the resulting clay-mineral orientation determined by X-ray techniques. Random orientation in the flocculated clay was preserved in the dried clay, which had dewatered slowly under minimal overburden pressure. Samples were compressed to study the influence of water content and pressure on the preservation of random orientation. Clay with lower water content showed less reorientation due to compression than clay with a higher content, suggesting that the amount of liquid water in proportion to adsorbed water in the system may influence clay-flake orientation. The soil concept in explaining the origin of underclay is discussed. Evidence indicates that the nonbedded character of underclays is due to the random orientation of clay flakes, which could be a primary feature resulting from the slow deposition of flocculated clay during which the clay dewaters under minimal overburden pressure. Observations by the author and others do not support the concept that most underclays in the Illinois Basin are soils subjected to subaerial weathering and reworking by plant rootlets.
Problems in the “Evidence” of “Evidence-Based Medicine”

The proposed practice of "evidence-based medicine," which calls for careful clinical judgment in evaluating the "best available evidence," should be differentiated from the special collection of data regarded as suitable evidence. Although the proposed practice does not seem new, the new collection of "best available" information has major constraints for the care of individual patients. Derived almost exclusively from randomized trials and meta-analyses, the data do not include many types of treatments or patients seen in clinical practice; and the results show comparative efficacy of treatment for an "average" randomized patient, not for pertinent subgroups formed by such cogent clinical features as severity of symptoms, illness, co-morbidity, and other clinical nuances. The intention-to-treat analyses do not reflect important post-randomization events leading to altered treatment; and the results seldom provide suitable background data when therapy is given prophylactically rather than remedially, or when therapeutic advantages are equivocal. Randomized trial information is also seldom available for issues in etiology, diagnosis, and prognosis, and for clinical decisions that depend on pathophysiologic changes, psychosocial factors and support, personal preferences of patients, and strategies for giving comfort and reassurance. The laudable goal of making clinical decisions based on evidence can be impaired by the restricted quality and scope of what is collected as "best available evidence." The authoritative aura given to the collection, however, may lead to major abuses that produce inappropriate guidelines or doctrinaire dogmas for clinical practice.
EFFECT OF SUBCOOLING ON CONVECTIVE MELTING OF A PARTICLE

We consider convective melting of a spherical particle. The study is intended to provide understanding of how both subcooling and convection of heat and mass affect the melting process. Since part of heat transferred to the particle is used to increase its sensible energy during melting by internal heat conduction, the heat transfer rate across the melting interface determines the melting rate. Subcooling of a particle affects the melting rate; therefore, if the effect of subcooling can be neglected during melting in calculating the melting rate, the Stefan number and heating rate must satisfy certain criteria that are described in this contribution. In addition, the effect of mass convection is also discussed
Kinetics of inorganic arsenopyrite oxidation in acidic aqueous solutions

Abstract In an effort to help evaluate the significance of common primary As-bearing minerals in releasing As into surface and ground waters, experiments were performed to determine rate laws for the irreversible inorganic aqueous oxidation of arsenopyrite by dissolved O2, Fe3+ and NO 3 - in low temperature acidic solutions. Batch reactor run conditions varied from pH 2–4.5 and 10–40 °C at ionic strength 0.01 M. A major constraint on defining and measuring the rate of arsenopyrite oxidation is the non-stoichiometry (incongruency) of the reaction in acidic solutions; As and S are not released completely into solution, apparently remaining behind as more slowly-dissolving solids in an Fe-depleted lattice. Therefore the rate of mineral oxidation (destruction) at low pH is best defined and measured by rates of change in total dissolved Fe concentrations, not by changes in dissolved As or S concentrations or Eh. The measured mineral dissolution rate therefore places an upper limit on actual inorganic As-release rates, providing a conservative basis for geochemical modeling that may over-predict, but not underestimate, As concentrations observed in natural settings. The molal specific rate laws for the oxidation of arsenopyrite by dissolved Fe3+ (pH 2) and O2 (pH 2–4.5), respectively, are: R sp,Fe 3 + ( moles mineral m - 2 s - 1 ) = - 10 - 5.00 ( M Fe 3 + ) 1.06 ± 0.11 R sp,O 2 aq ( moles mineral m - 2 s - 1 ) = - 10 - 6.11 ( M O 2 aq ) 0.33 ± 0.18 ( M H + ) 0.27 ± 0.09 The results indicate that Fe3+ oxidizes arsenopyrite at least 10 times faster than dissolved O2. Nitrate does not oxidize arsenopyrite. At low pH arsenopyrite oxidizes 3–4 orders of magnitude faster than (arsenical) pyrite and 4–5 orders of magnitude faster than realgar and orpiment. Therefore in rocks with low ratios of arsenopyrite to other As-bearing sulfides, including coals and ores, arsenopyrite oxidation can still be the dominant source of As-release from sulfide minerals. In natural settings undergoing long-term arsenopyrite oxidation at low pH (in the absence of secondary phases such as scorodite and Fe hydroxides), the rate of As-release may ultimately be controlled by the rate of dissolution of As–S compounds that form on the Fe-depleted arsenopyrite mineral surface. Rate data are therefore needed on native As, realgar and orpiment at low pH, as proxies for these compounds.
Enantioselective synthesis of alkyne-substituted quaternary carbon stereogenic centers through NHC-Cu-catalyzed allylic substitution reactions with (i-Bu)2(alkynyl)aluminum reagents.

A catalytic enantioselective method for the formation of alkyne-substituted all-carbon quaternary stereogenic centers is reported. Additions of alkynylaluminums to alkyl-, aryl-, carboxylic ester-, or silyl-substituted allylic phosphates are promoted by 1.0−5.0 mol % loadings of NHC−Cu complexes derived from air-stable and commercially available CuCl2·2H2O. The requisite Al-based reagents are prepared through treatment of the corresponding aryl-, heteroaryl-, alkyl-, or alkenyl-substituted terminal alkynes with diisobutylaluminum hydride in the presence of 5.0 mol % Et3N at ambient temperature. The desired 1,4-enynes are obtained in up to 98% yield and >99:1 enantiomeric ratio. Selected Au-catalyzed cyclizations involving the alkyne unit of the enantiomerically enriched products are presented as a demonstration of the method’s utility in chemical synthesis.
Why do some people with panic disorders become avoidant?: A review

Abstract The literature bearing on the issue of why some individuals with panic disorder develop avoidance of various degrees of severity while others do not was examined. The data were organized around seven hypotheses. The evidence linking measures of panic disorder severity and avoidance was contradictory. Clearer evidence was found for the relationship of several cognitive-expectational measures and avoidance, including expectations for panic attacks in specific situations, expectations for negative outcomes, and expectations for inability to utilize adequate coping strategies. Additional relationships were found between gender, with females more likely to develop avoidance than males, and depression, with avoiders more likely to be depressed. The results were examined from the guiding hypotheses. A critique of current methodology was offered as well as suggestions for future research directions.
Observed Hazards to Aircraft in Deep Summertime Convective Clouds from 4–7 km

Data from flights by the South Dakota School of Mines and Technology’s North American T-28 storm-penetrating aircraft during nine different research projects conducted between 1991 and 2003 are analyzed. These flights, usually flown during the summer months in the central and high plains in the United States, targeted regions of convective storms containing vigorous updrafts, downdrafts, and precipitation, including hail. Observations indicate that three of the most hazardous components of flying in summertime deep convective clouds are aircraft icing, turbulence from strong vertical wind gradients, and hail. There is also a smaller, but still important, threat from lightning. Statistics of the observations show that at any given time there is approximately a 10% probability of encountering severe icing conditions, approximately a 0.1% probability of encountering extreme turbulence, and approximately a 0.2% probability of encountering hail with mean diameter 2.5 cm or greater within convective clouds in t...
Periocular squamous cell carcinoma.

BACKGROUND We present a case report of periocular squamous cell carcinoma and a review of the literature with emphasis on early diagnosis, proper follow-up and management, reconstructive options, and new immunomodulatory therapies. OBJECTIVE The objective is to guide the dermatologist and the dermatologic surgeon in proper management and continued care of patients with periocular squamous cell carcinoma in light of its propensity for perineural involvement and regional lymphatic metastases. MATERIALS AND METHODS A MEDLINE, Ovid, and PubMed search was conducted for recent relevant articles pertaining to “periocular,”“periorbital,”“squamous cell” carcinoma, and their “surgery”“treatment” modalities. CONCLUSIONS Periocular squamous cell carcinoma is an aggressive tumor, characterized by perineural involvement and an overall rate of regional lymph node metastases reported to range from 10% to as high as 20% to 25%. Increased vigilance must be undertaken when treating these high-risk tumors. Mohs micrographic surgery or excision with frozen section analysis is the standard of care for periocular squamous cell carcinoma. Multiple options exist for the reconstruction of the postoperative defect that allow for excellent function and cosmesis. Finally, research into new immunomodulators will hopefully lead to an increased understanding of the aggressive nature of periocular squamous cell carcinoma and potential aid in the treatment of the tumor.
Proteomic identification of new biomarkers and application in thyroid cytology.

Objective To validate proteins identified by proteomics as potentially usable markers in thyroid pathology. Study design Frozen sections of thyroid tumors were manually micro-dissected and proteins extracted. Two-dimensional (2D) gel electrophoresis and subsequent liquid chromatography/mass spectroscopy were performed, and differentially expressed proteins were identified. Validation of candidates for tumor markers (galectin-1, galectin-3, S100C and voltage-dependent anion channel 1 [VDAC1]) was done by immunohistochemistry in 21 cell blocks from fine needle aspiration biopsies (FNAB) and corresponding histology specimens (13 cases). Results Galectin-3 was negative in benign lesions and positive in FNAB from papillary carcinoma (5 of 5), follicular variant of papillary carcinoma (1 of 4) and follicular carcinoma (1 of 2). S100C was positive in some benign lesions: hyperplasia (2 of 4), goiter (1 of 3) and follicular adenoma (1 of 3), with predominantly nuclear pattern of staining. S100C was positive in malignant lesions, showing cytoplasmic location. Galectin-1 was negative in benign lesions and positive in follicular carcinoma (1 of 2), papillary carcinoma (2 of 5) and follicular variant of papillary carcinoma (1 of 4). VDAC1 was detected in benign and malignant lesions, showing a strong positivity in follicular carcinomas. Conclusion Immunohistochemical validation of potential markers is a crucial step before clinical application in diagnosis. Galectin-3, galectin-1 and S100C can be used to help in discriminating benign and malignant thyroid lesions.
Comparison of the In Vitro Activities of HR756 with Cephalothin, Cefoxitin, and Cefamandole

The in vitro activity of HR756, a new semisynthetic cephalosporin, was compared with the activities of cephalothin, cefoxitin, and cefamandole against 1,535 isolates of gram-positive and gram-negative bacteria. HR756 was less active than cephalothin and cefamandole and twofold more active than cefoxitin against Staphylococcus. All four of the antibiotics were inactive against the enterococcus group of Streptococcus; however, HR756 was the most active antibiotic against the other isolates of Streptococcus. HR756 was also more active against isolates of Enterobacteriaceae, including 84 to 95% of the isolates resistant to one or more of the other three antibiotics. HR756, at a concentration of 12.5 mug/ml, inhibited 86, 75, and 100% of the isolates of Pseudomonas aeruginosa, other Pseudomonas species, and Acinetobacter, respectively. The minimal inhibitory concentrations and minimal bactericidal concentrations of HR756 were within one twofold dilution for 11 of 21 gram-positive cocci and 119 of 125 gram-negative bacilli tested.
Beta-catenin and E-cadherin expression patterns in high-grade endometrial carcinoma are associated with histological subtype.

Both beta-catenin and E-cadherin are epithelial cell adhesion molecules. In addition, beta-catenin is an important element of the Wnt signal transduction pathway, which has been implicated in embryogenesis and carcinogenesis, including the development of endometrial and ovarian endometrioid carcinomas. We hypothesized that the expression pattern of these two adhesion molecules may depend upon the histological subtype of endometrial carcinomas. Therefore, we compared the immunohistochemical expression of beta-catenin and E-cadherin in a set of uterine adenocarcinomas matched for high histologic grade, that is, poorly differentiated (International Federation of Gynecology and Obstetrics [FIGO] Grade III) uterine endometrioid carcinomas and uterine serous carcinomas. Seventeen FIGO Grade III endometrioid adenocarcinomas and 17 serous carcinomas were evaluated histologically and immunohistochemically with commercially available monoclonal antibodies against beta-catenin and E-cadherin. Nuclear expression of beta-catenin was observed in 8 of 17 (47%) endometrioid adenocarcinomas but in none of the serous carcinomas (P = .003). Moderate or strong E-cadherin expression was identified in 7 of 17 (41%) serous carcinomas as opposed to in only 1 of 17 (6%) endometrioid adenocarcinomas (P = .02). The majority of endometrioid adenocarcinomas showed strong beta-catenin expression coupled with weak E-cadherin expression; serous carcinomas did not exhibit a comparable trend. Our results indicate that the expression of beta-catenin and E-cadherin in high-grade endometrial cancers is strongly associated with histological subtype. These data provide further support for the distinct molecular profiles of endometrioid adenocarcinoma and serous carcinoma. Notably, differences in cell adhesion molecule expression could account for variations in patterns of tumor dissemination. The immunohistochemical staining pattern may also be useful for diagnostic purposes.
Interview: André Dosé, CEO of Swiss international airlines

ndre Dose may very well be the unknown dark horse in the airline industry, but what he lacks in international recognition, he makes up in drive and determination. Appointed CEO of Crossair in late 2000, Andre took over the top job at Crossair so that Crossair’s previous CEO and Founder Moritz Suter could leave the company to become president of Swissair. Suter left his job as Swissair CEO a few weeks into the post convinced that he was unable to fulfill his mission, followed rapidly thereafter by a mass resignation of most of the Swissair board. Mario Corti, previously CFO of Nestle was given the top job at Swissair, and immediately tapped Andre Dose into Swissair’s management committee. The next year was critical for Swissair, and Dose, sitting as one of the top management officers for Swissair as well as CEO of Crossair, was well placed to experience firsthand the events leading up to Swissair’s demise.
Structure of Dipalmitoylphosphatidylcholine/Cholesterol Bilayer at Low and High Cholesterol Concentrations: Molecular Dynamics Simulation

By using molecular dynamics simulation technique we studied the changes occurring in membranes constructed of dipalmitoylphosphatidylcholine (DPPC) and cholesterol at 8:1 and 1:1 ratios. We tested two different initial arrangements of cholesterol molecules for a 1:1 ratio. The main difference between two initial structures is the average number of nearest-neighbor DPPC molecules around the cholesterol molecule. Our simulations were performed at constant temperature (T = 50 degrees C) and pressure (P = 0 atm). Durations of the runs were 2 ns. The structure of the DPPC/cholesterol membrane was characterized by calculating the order parameter profiles for the hydrocarbon chains, atom distributions, average number of gauche defects, and membrane dipole potentials. We found that adding cholesterol to membranes results in a condensing effect: the average area of membrane becomes smaller, hydrocarbon chains of DPPC have higher order, and the probability of gauche defects in DPPC tails is lower. Our results are in agreement with the data available from experiments.
Practical formal correctness checking of million-core problem solving environments for HPC

While formal correctness checking methods have been deployed at scale in a number of important practical domains, we believe that such an experiment has yet to occur in the domain of high performance computing at the scale of a million CPU cores. This paper presents preliminary results from the Uintah Runtime Verification (URV) project that has been launched with this objective. Uintah is an asynchronous task-graph based problem-solving environment that has shown promising results on problems as diverse as fluid-structure interaction and turbulent combustion at well over 200K cores to date. Uintah has been tested on leading platforms such as Kraken, Keenland, and Titan consisting of multicore CPUs and GPUs, incorporates several innovative design features, and is following a roadmap for development well into the million core regime. The main results from the URV project to date are crystallized in two observations: (1) A diverse array of well-known ideas from light-weight formal methods and testing/observing HPC systems at scale have an excellent chance of succeeding. The real challenges are in finding out exactly which combinations of ideas to deploy, and where. (2) Large-scale problem solving environments for HPC must be designed such that they can be "crashed early" (at smaller scales of deployment) and "crashed often" (have effective ways of input generation and schedule perturbation that cause vulnerabilities to be attacked with higher probability). Furthermore, following each crash, one must "explain well" (given the extremely obscure ways in which an error finally manifests itself, we must develop ways to record information leading up to the crash in informative ways, to minimize off-site debugging burden). Our plans to achieve these goals and to measure our success are described. We also highlight some of the broadly applicable concepts and approaches.
Does Dexamethasone with Preemptive Analgesia Improve Pediatric Tonsillectomy Pain

Abstract Objective: The study goal was to determine whether the combination of dexamethasone with preemptive analgesia has an additive effect in further improving recovery. Study Design: We conducted a prospective, randomized, double-blinded trial of 50 children undergoing tonsillectomy at a university ambulatory surgery center. One study group received 1 intravenous dose of dexamethasone, and another group received 1 dose of saline solution. All patients received tonsillar fossa injections of ropivacaine plus clonidine before tonsil excision. Results: The 2 study groups were similar in main outcome measurements. Pain intensity and quality of life were not statistically different between the groups. There was a small trend to less trismus and less cumulative codeine use in the steroid group. Overall, there was a very low incidence of nausea and vomiting in both groups, which may have been due to the preemptive analgesia. Conclusion: Dexamethasone does not significantly improve the morbidity of pediatric tonsillectomy when preemptive analgesia with ropivacaine and clonidine is used concurrently. (Otolaryngol Head Neck Surg 2002;126:307-15.)
Second-order derivatives in a local frame developed in spheroidal and spherical coordinates

Second-order derivatives of a general scalar function of position (F) with respect to the length elements along a family of local Cartesian axes are developed in the spheroidal and spherical coordinate systems. A link between the two kinds of formulations is established when the results in spherical coordinates are confirmed also indirectly, through a transformation from spheroidal coordinates. IfF becomesW (earth's potential) the six distinct second-order derivatives—which include one vertical and two horizontal gradients of gravity—relate the symmetric Marussi tensor to the curvature parameters of the field. The general formulas for the second-order derivatives ofF are specialized to yield the second-order derivatives ofU (standard potential) and ofT (disturbing potential), which allows the latter to be modeled by a suitable set of parameters. The second-order derivatives ofT in which the property ΔT=0 is explicitly incorporated are also given. According to the required precision, the spherical approximation may or may not be desirable; both kinds of results are presented. The derived formulas can be used for modeling of the second-order derivatives ofW orT at the ground level as well as at higher altitudes. They can be further applied in a rotating or a nonrotating field. The development in this paper is based on the tensor approach to theoretical geodesy, introduced by Marussi [1951] and further elaborated by Hotine [1969], which can lead to significantly shorter demonstrations when compared to conventional approaches.
MEDIATORS OF INFLAMMATION IN LEUKOCYTE LYSOSOMES VI. PARTIAL PURIFICATION AND CHARACTERIZATION OF A MAST CELL-RUPTURING COMPONENT

The mast cell-rupturing component present in the lysosomes of rabbit exudate PMN neutrophil leukocytes has been identified and some of its physical and chemical properties have been described. The active agent is a low molecular weight (1200 to 2400) polypeptide containing a relatively large proportion of the basic amino acid, arginine. It is thermostable and dialyzable, and does not cause contraction of the isolated guinea pig ileum. The mast cell-rupturing activity of the agent is destroyed by trypsin. A second permeability factor with a larger molecular weight is present in crude extracts of PMN granules. Although this substance does not lyse mast cells, it is capable of evoking delayed permeability responses in rabbit skin.
IL-4 production by PBMCs on stimulation with mite allergen is correlated with the level of serum IgE antibody against mite in children with bronchial asthma.

Abstract Background: Although IL-4, IL-13, and IFN-γ are known to affect IgE synthesis, it remains unclear which one plays the most important role in in vivo IgE synthesis in atopic patients. Objective: The aim of this study is to clarify the difference in importance among these cytokines in up-regulation of IgE synthesis in atopic patients. Methods: We measured IL-4, IL-13, and IFN-γ production by PBMCs on stimulation with house dust mite (HDM) in 23 children, 3 to 15 years old, with bronchial asthma (BA) and analyzed the correlation with HDM-specific IgE antibody levels expressed as HDM IgE radioallergosorbent test (RAST) results. Results: The production of IL-4 and IL-13 by PBMCs on stimulation with HDM was significantly higher in children with BA than in nonatopic control subjects (IL-4, 752.9 ± 365.9 vs 312.3 ± 230.0 fg/mL, P
Assessment of quality of life: a medical imperative.

In caring for patients with chronic illness, particularly those chronic illnesses for which there are a number of comparably effective therapies as regards biomedical outcomes, important additional considerations include the assessment of the quality of life by the measurement of physical symptoms, general well-being, and emotional, intellectual, and social functioning.
Wall-interference corrections for parachutes in a closed wind tunnel

An extensive test program was conducted to gather information on wall-interference effects for parachutes in closed wind tunnels. Drag area and base pressure measurements were made for a set of ribbon parachutes of 7%, 15% and 30% geometric porosity in six different wind tunnels, covering a range of geometric blockages from two to thirty-five percent. The resulting data have been used to formulate and validate approximate blockage correction equations based on the theory of Maskell. The corrections are applicable to single parachutes and clusters of two and three parachutes. 8 refs., 7 figs., 1 tab.
Annoyance and health reactions to odor from refineries and other industries in Carson, California 1972.

Several studies previously conducted in California and elsewhere on the effects of odor from industrial sources have domonstrated that annoyance reactions, as measured by personal interviews, are related both to presumptive exposure to odor, as estimated from geographic location with respect to sources, and to systematic measurements of exposure made by dynamic olfactometry. The sources of odors in the California studies were pulp and paper mills which represented point sources. The paper is a report of the effects of community exposure to multiple sources of odor associated with petroelum refineries and other components of the petrochemical industry. An estimate was made of the annoyance reactions and possible health effects of exposure to odor and to determine whether they are related to measurements made by dynamic olfactometry.
Air quality model performance evaluation

This paper reviews methods to evaluate the performance of air quality models, which are tools that predict the fate of gases and aerosols upon their release into the atmosphere. Because of the large economic, public health, and environmental impacts often associated with the use of air quality model results, it is important that these models be properly evaluated. A comprehensive model evaluation methodology makes use of scientific assessments of the model technical algorithms, statistical evaluations using field or laboratory data, and operational assessments by users in real-world applications. The focus of the current paper is on the statistical evaluation component. It is important that a statistical model evaluation exercise should start with clear definitions of the evaluation objectives and specification of hypotheses to be tested. A review is given of a set of model evaluation methodologies, including the BOOT and the ASTM evaluation software, Taylor’s nomogram, the figure of merit in space, and the CDF approach. Because there is not a single best performance measure or best evaluation methodology, it is recommended that a suite of different performance measures be applied. Suggestions are given concerning the magnitudes of the performance measures expected of “good” models. For example, a good model should have a relative mean bias less than about 30% and a relative scatter less than about a factor of two. In order to demonstrate some of the air quality model evaluation methodologies, two simple baseline urban dispersion models are evaluated using the Salt Lake City Urban 2000 field data. The importance of assumptions concerning details such as minimum concentration and pairing of data are shown. Typical plots and tables are presented, including determinations of whether the difference in the relative mean bias between the two models is statistically significant at the 95% confidence level.
Lignin abnormalities of "rubbery apple wood".

The lignin from healthy and from rubbery wood virus-infected apple trees has been examined. Although the Klason lignin from healthy specimen was found to be similar to that of other hardwood specie...
Relation of collagen synthesis to chondroitin sulfate synthesis in cartilage

Abstract The question of whether the formation of mucopolysaccharide and collagen are mutually dependent processes was studied in an in vitro system. Puppy epiphyseal cartilage was incubated in the presence of sodium salicylate or a , a ′-dipyridyl in an attempt to inhibit the biosynthesis of mucopolysaccharides or collagen, respectively. The incorporation of glucose- 14 C or glucosamine- 14 C into isolated chondroitin sulfate and the incorporation of proline-H 3 into collagen hydroxyproline and into noncollagen protein were used as measures of biosynthesis. Salicylate markedly reduced chondroitin sulfate synthesis, presumably by inhibition of the enzyme l -glutamine- d -fructose-6-phosphate amino transferase. Since it was not possible to overcome this inhibition by supplying glucosamine, it was concluded that other enzymes involved in cartilage chondroitin sulfate synthesis are also inhibited, as has been demonstrated for the gastric mucosal synthesis of mucoprotein. Salicylate did not affect the production of noncollagen protein but greatly reduced the incorporation of label into the 0.14 M NaCl extractable collagen fraction. The incorporation into the 0.45 M NaCl extractable and insoluble collagen fractions was relatively unaffected. It was shown that the transfer of activity from the 0.14 M NaCl to the 0.45 M NaCl fraction and then to the insoluble fraction was increased in the presence of salicylate, and this was felt to be indicative of accelerated aggregation of collagen molecules into a cross-linked fibrillar form. The inhibition of collagen synthesis by a , a ′-dipyridyl was initially accompanied by relatively little effect on the chondroitin sulfate, but at the later time points a large reduction of labeled glucose incorporation was seen. As with salicylate, the addition of dipyridyl did not affect noncollagen protein synthesis, suggesting that general inhibition of cell metabolism is not the reason for the effects seen. When chondroitin sulfate was isolated and fractionated by a procedure dependent upon molecular weight differences, it was found that the radioactivity was associated almost exclusively with the higher molecular weight material. It was concluded that some degree of interaction exists between the biosyntheses of collagen and chondroitin sulfate.
Social Media and Physicians’ Online Identity Crisis

Recognizing this challenge and given reports of physician misconduct online, institutions, medical boards, and physician organizations worldwide have promulgated recommendations for physician use of social media. A common theme among these recommendations—with a recent example from the American College of Physicians and Federation of State Medical Boards4—is that physicians should manage patient-physician boundaries online by separating their professional and personal identities. In this Viewpoint, we contend that this is operationally impossible, lacking in agreement among active physician social media users, inconsistent with the concept of professional identity, and potentially harmful to physicians and patients. A simpler approach that avoids these pitfalls asks physicians not whether potential social media content is personal or professional but whether it is appropriate for a public space.
Sampling rates and image reconstruction from scattered fields

Cepstral filtering is reviewed as a suitable and efficient method to solve the inverse scattering problem in the case of strongly scattering permittivity distributions. The number and distribution of measured scattered field data required is discussed, as is the effective number of degrees of freedom available to describe the scattering structure. The latter is identified as a key parameter determining the performance of the cepstral method. This is of particular importance for strong scattering and nonlinear image processing methods since many data sets are compiled based on the sampling requirements of weakly scattering objects. We find that the domain of the object support and the maximum permittivity contrast are important prior information for determining the minimum number of data samples necessary while maximizing use of the available degrees of freedom; examples are presented.
MODELING MEDIATION IN THE ETIOLOGY OF VIOLENT BEHAVIOR IN ADOLESCENCE: A TEST OF THE SOCIAL DEVELOPMENT MODEL*

The social development model seeks to explain human behavior through specification of predictive and mediating developmental relationships. It incorporates the effects of empirical predictors (“risk factors” and “protective factors”) for antisocial behavior and seeks to synthesize the most strongly supported propositions of control theory, social learning theory, and differential association theory. This article examines the fit of the social development model using constructs measured at ages 10, 13, 14, and 16 to predict violent behavior at age 18. The sample of 808 is from the longitudinal panel of the Seattle Social Development Project, which in 1985 surveyed fifth-grade students from schools serving high crime neighborhoods in Seattle, Washington. Structural equation modeling techniques were used to examine the fit of the model to the data. The model fit the data (CFI ≥.90, RMSEA ≤.05). We conclude that the social development model adequately predicts violence at age 18 and mediates much of the effect of prior violence. Implications for theory and for prevention are discussed.
Contaminant infiltration into a pressurized structure with fabric walls

The control volume technique is used to model the two-dimensional transport of windborne contaminant and its infiltration through porous fabric walls to the interior of a chamber maintained at a slight overpressure. The flow characteristics for the fabric are modelled using a source term in the momentum equations that is analogous to the Ergun equation for packed columns. The diffusion coefficient in the concentration equation for the fabric is obtained using results from the mechanics of composite materials. It is shown that slight overpressures can keep the contaminant level within the chamber low.
Human rights violations and smoking status among South African adults enrolled in the South Africa Stress and Health (SASH) study.

Despite South Africa's history of violent political conflict, and the link between stressful experiences and smoking in the literature, no public health study has examined South Africans' experiences of human rights violations and smoking. Using data from participants in the nationally representative cross-sectional South Africa Stress and Health study (SASH), this analysis examined the association between respondent smoking status and both human rights violations experienced by the respondent and violations experienced by the respondents' close friends and family members. SAS-Callable SUDAAN was used to construct separate log-binomial models by political affiliation during apartheid (government or liberation supporters). In comparison to those who reported no violations, in adjusted analyses, government supporters who reported violations of themselves but not others (RR = 1.76, 95% CI: 1.25-2.46) had a significantly higher smoking prevalence. In comparison to liberation supporters who reported no violations, those who reported violations of self only (RR = 1.56, 95%CI: 1.07-2.29), close others only (RR = 1.97, 95%CI: 1.12-3.47), or violations of self and close others due to close others' political beliefs and the respondent's political beliefs (RR = 2.86, 95%CI: 1.70-4.82) had a significantly higher prevalence of smoking. The results of this analysis suggest that a relationship may exist between human rights violations and smoking among South Africa adults. Future research should use longitudinal data to assess causality, test the generalizability of these findings, and consider how to apply these findings to smoking cessation interventions. Language: en
Peak expiratory flow during a passive exhalation: an index of expiratory resistance during anesthesia.

During a passive exhalation performed between (FRC + VT) and FRC, peak expiratory flow (VmaxE) varies as a function of the respiratory system expiratory resistance, RT, with the following relationship: VmaxE = VT/(RT . CT), where Cr is the total respiratory system compliance (static). This expression assumes: (1) a laminar flow regimen during expiration, and (2) a constant CT value over the range of VT. Both these conditions are usually attained during controlled ventilation in the apneic patient. VmaxE can be monitored continuously with relative ease, and may represent a simple and useful index of the mechanical properties of the respiratory system in the anesthetized patient.
The Relationship between English Language Learner Status and Music Ensemble Participation.

Authors of previous research have reported that U.S. English language learner (ELL) students participate in school-sponsored music ensembles (band, orchestra, and choir) at a lower rate than their native-English-speaking peers (non-ELLs). The current study examined this phenomenon using a nationally representative sample of U.S. 10th graders (14- to 16-year-olds across 751 high schools, N = 15,011) to estimate school music ensemble participation rates for ELL and non-ELL students. Consistent with prior research, initial results indicated that individual ELL status was a significant, negative predictor of participation. However, when our analyses took into account student socioeconomic status and academic achievement, results provided no evidence that ELL students participate in ensembles at different rates than non-ELL students. Results also indicate that school membership accounted for different ensemble participation rates. It may be that lack of opportunity—not lack of interest—explains the gap between...
Explaining Gender-Based Selection Decisions: A Synthesis Of contextual and Cognitive Approaches

In this article we integrate contextual and cognitive explanations for gender-based selection in the workplace; we also consider the implications of this integration for understanding gender segregation. We argue that decision makers' propensity to use applicant gender as a basis for hiring and promotion decisions varies systematically across organizational contexts. We explore specific ways in which organizational context influences decision makers' development and use of gender-associated schemas of typical jobholders. We also argue that the interaction between context and cognition may be partially responsible for the persistence of gender segregation. Finally, we discuss the implications of our approach for the practice of personnel selection and research on selection and gender segregation.
CMB Polarization at Large Angular Scales: Data Analysis of the POLAR Experiment

The coming flood of cosmic microwave background (CMB) polarization experiments, spurred by the recent detection of CMB polarization by the DASI and WMAP instruments, will be confronted by many new analysis tasks specific to polarization. For the analysis of CMB polarization data sets, the devil is truly in the details. With this in mind, we present details of the data analysis for the POLAR experiment, which recently led to the tightest upper limits on the polarization of the cosmic microwave background radiation at large angular scales. We discuss the data selection process, map-making algorithms, offset removal, and likelihood analysis which were used to find upper limits on the polarization. Stated using the modern convention for reporting CMB Stokes parameters, these limits are 5.0 \ensuremath{\mu}K on both E- and B-type polarization at 95% confidence. Finally, we discuss simulations used to test our analysis techniques and to probe the fundamental limitations of the experiment.