cssi/SciSciGPT-SciSciNet huggingface dataset:
Comparison of calcium effect on in vitro calcitonin and parathyroid hormone release by young and aged thyroparathyroid glands.

Abstract Serum immunoreactive parathyroid hormone (iPTH) and calcitonin (iCT) levels are higher in young than aged rats. However, serum calcium concentration does not change with age suggesting that the calcium regulation of PTH and CT secretion may be affected by aging. We compared iPTH and iCT secretion in vitro at low and high calcium concentrations using thyroparathyroid glands removed from young (2–3 months), adult (12–13 months), and old (24–27 months) F-344 male rats fed regular rat chow. Glands from each animal were incubated for 3 h in serum-free culture media containing 1.0 mM calcium and then transfered to media containing 2.5 mM calcium for another 3 h. Immunoreactive PTH and iCT concentrations of the media after each incubation period were determined by radioimmunoassay. Immunoreactive PTH and iCT secretion per pair of glands was significantly higher in glands from older animals regardless of calcium concentrations. The decrease in iPTH, and increment in iCT, secretion in response to 2.5 mM calcium by glands from old rats was smaller than that observed for glands from young animals. These age-related related changes in regulation of secretion bu calcium may contribute to the increased iPTH and iCT secretion and serum levels seen in older animals.
Incarcerated Morgagni hernia mimicking acute cholecystitis

A 64-year-old man presented with sharp, constant right upper quadrant pain, nausea, and constipation for 2 days. The patient reported intermittent right upper quadrant pain for the prior 6 years, which was exacerbated by eating, but noted that over the past 2 days the pain had become more severe. The patient had previously undergone three right upper quadrant ultrasound studies that were all negative for acute cholecystitis. On presentation, examination was notable for focal tenderness to palpation over the xiphoid process. A right upper quadrant ultrasound study was completed, and demonstrated a single hepatic cyst and gallbladder sludge without evidence of gallstones, gallbladder wall thickening, pericholecystic fluid, or a sonographic Murphy’s sign (Fig. 1). A chest radiograph was obtained, and demonstrated elevation of the right hemidiaphragm with colonic interposition in the right upper quadrant (Fig. 2). Computed tomography of the abdomen and pelvis with intravenous and oral contrast was performed, and demonstrated a large right-sided anterior diaphragmatic hernia containing distended loops of colon with short segment narrowing at the entrance as well as soft tissue stranding and simple fluid within the herniation sac, consistent with an incarcerated Morgagni hernia (Fig. 3). The patient underwent laparoscopic diaphragmatic hernia repair with mesh, which was complicated by postoperative development of a right pneumothorax, but with eventual normalization of the chest radiograph (Fig. 4) and resolution of the right upper quadrant pain.
Functional coordination of microtubule-based and actin-based motility in melanophores

Abstract The fish melanophore has been considered the exemplar of microtubule-based organelle transport. In this system, a radial array of uniformly polarized microtubules [1] provides a framework on which dynein-related and kinesin-related motors drive pigment granules toward the minus or plus ends, respectively [2–4]. Stimulation of minus-end motors accounts satisfactorily for aggregation of granules at the cell center. Rapid dispersion is clearly microtubule-dependent; however, the uniform distribution of granules throughout the cytoplasm is paradoxical because stimulation of plus-end motors is predicted to drive the granules to the cell margin. This paradox suggested that the transport system was incompletely understood. Here, we report the discovery of a microtubule-independent motility system in fish melanophores. The system is based on actin filaments and is required for achieving uniform distribution of pigment granules. When it is abrogated, granules accumulate at the cell's margin as predicted for microtubule plus-end motors acting alone. The results presented here demonstrate the functional coordination of microtubule and actin filament systems, a finding that may be of general significance for organelle motility in cytoplasm.
Toward stochastic anatomy of inter-meeting time distribution under general mobility models

Recent discovery of the mixture (power-law and exponential) behavior of inter-meeting time distribution of mobile nodes presents new challenge to the problem of mobility modeling and its effect on the network performance. Existing studies on this problem via the average inter-meeting time become insufficient when the inter-meeting time distribution starts to deviate from exponential one. This insufficiency necessarily leads to the increasing difficulty in the performance analysis of forwarding algorithms in mobile ad-hoc networks (MANET). In this paper, we analyze the effect of mobility patterns on the inter-meeting time distribution. We first identify the critical timescale in the inter-meeting distribution, at which the transition from power-law to exponential takes place, in terms of the domain size and the statistics of the mobility pattern. We then prove that stronger correlations in mobility patterns lead to heavier (non-exponential) 'head' of the inter-meeting time distribution. We also prove that there exists an invariance property for several contact-based metrics such as inter-meeting, contact, inter-any-contact time under both distance-based (Boolean) and physical interference (SINR) based models, in that the averages of those contact-based metrics do not depend on the degree of correlations in the mobility patterns. Our results collectively suggest a convex ordering relationship among inter-meeting times of various mobility models indexed by their degrees of correlation, which is in good agreement with the ordering of network performance under a set of mobility patterns whose inter-meeting time distributions have power-law 'head' followed by exponential 'tail'.
CRiT walking race, place, and space in the academy

This article is a commentary on several issues relevant to critical race theory (CRT), education, and race‐related discourse. In this article, we hope to contribute to the dialogue on race and education, and raise a few thought‐provoking questions regarding ways of seeing and thinking about CRT as both a theoretical and practical tool when focused on issues of race, structural racism, and education.
Management issues in paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PNH) arises in the setting of bone marrow injury. Thus, management decisions must take into account whether symptoms are a consequence of the underlying marrow failure or of the expansion of the clone of thePIG-A mutant hematopoietic cells. The primary clinical manifestations of PNH are intravascular hemolysis and thrombophilia. Currently available options for treatment of the hemolysis of PNH are unsatisfactory, but the recent development of specific inhibitors of complement for use in treating human disease should make possible effective management of this pathology. The fundamental basis of the thrombophilia of PNH has not been elucidated. Currently, empiric anticoagulant therapy is the foundation for treating the thromboembolic complications of PNH. The role of warfarin prophylaxis, however, remains an area of active debate. Pregnancy in a patient with PNH presents special concerns about fetal/maternal well-being because of the high potential for thromboembolic complications. Bone marrow transplantation can be considered curative, but the decision to recommend this treatment must take into account factors related both to PNH and to comorbid conditions. Refining the technology for both gene therapy (by transducing stem cells with a functionalPIG-A gene) and autotransplantation (by using stem cells selected for the expression of glycosyl phosphatidylinositol-anchored proteins) remain challenges for the future.
Analysis of cytotoxicities of platinum compounds

Extent of DNA platination, loss of cell viability, DNA fragmentation, and impairment of cellular mitochondrial oxygen consumption are measures of drug cytotoxicity. We measured and compared these effects for cisplatin, oxaliplatin and carboplatin. Because reaction with intracellular thiols may be responsible for drug resistance, we also determined the rates of Pt drug reactions with metallothionein. Jurkat cells were exposed at 37 degrees C to 25 microM Pt drugs for 3 h. Pt-DNA adducts were determined at the end of the incubation period by atomic absorption spectroscopy. Viability, DNA fragmentation, and cellular respiration (microM O2/min/10(6) cells) were determined 24 h post drug exposure. The average amount of Pt-DNA adducts (Pt atoms/10(6) nucleotides) produced by cisplatin was 43.4, by oxaliplatin 4.8 and by carboplatin 1.5. Cisplatin decreased the rate of respiration by approximately 63% and oxaliplatin by approximately 37%. DNA fragmentation by cisplatin and oxaliplatin was very similar. Carboplatin produced an unnoticeable effect on cellular respiration, and only approximately 10% of the DNA fragmentation was produced by cisplatin or oxaliplatin. Although, for a given drug, all four measures of cytotoxicity were proportional, this did not hold for comparisons between the drugs. The rate constants (M-1 s-1) for reaction of cisplatin, oxaliplatin and carboplatin with Cd/Zn thionein were 0.75, 0.44 and 0.012, respectively. For comparison, the rate constants (M-1 s-1) for reaction of cisplatin, oxaliplatin and carboplatin with glutathione were 0.027, 0.038 and 0.0012, respectively. The low reactivity of carboplatin with metallothionein and glutathione suggests that its low cytotoxic activities are not due to reaction of Pt2+ with cellular thiols. Despite a tenfold difference in Pt-DNA adducts between cisplatin and oxaliplatin, the cytotoxicities of these compounds are very similar, suggesting that oxaliplatin lesions are more potent than cisplatin lesions. The results demonstrate a large influence of the ligands occupying Pt coordination spheres on the chemical and biologic activities of Pt drugs.
Late-Terminal Classic Maya Pottery in Northern Belize: A Petrographic Analysis of Sherd Samples from Colha and Kichpanha

Abstract Two petrographic studies of Late-Terminal Classic ( ad 680–850) Maya ceramic sherds from northern Belize provide evidence of significant inter- and intra-site technological variability. An initial study of Subin Red sherds from Colha and Kichpanha indicates the predominance of quartz inclusions in vessels of this type from both sites, but suggests inter-site differences as well. Moreover, the extensive use of quartzitic clays in ceramics, which had not been identified in previous petrographic studies of archaeological ceramics in northern Belize, appears to represent a departure, distinctive to this region, from an earlier, widespread ceramic tradition based on the exploitation of fine calcareous clays. A second study of sherds drawn from three of the most prevalent pottery types in the Late-Terminal Classic Masson Complex at Colha further confirms this pattern. Comparisons with local clay samples suggest this new technology represents less selective use of available clay resources during this period. Results also suggest significant intra-site variability in ceramic composition and appear to support other lines of evidence indicating the formation of a Late-Terminal Classic political sphere extending from San Estevan in the north to the Northern River Lagoon site in the south.
INNOVATIVE MANAGEMENT OF AGRICULTURAL PHOSPHORUS TO PROTECT SOIL AND WATER RESOURCES

Agriculture, particularly livestock agriculture, is receiving increasing public scrutiny due to non-point source phosphorus (P) pollution and eutrophication. Much of today's situation may be attributed to system level trends in specialization and intensification that result in excess P entering livestock farms. Balancing P at the farm gate represents a necessary step for long-term soil and water quality protection. Remedial P management combines source and transport control that confront critical areas of P export in surface and subsurface runoff from agricultural landscapes. Source management seeks to immobilize P in the environment through such strategies as reducing soluble P in manure, targeting P application to soils with high retention capacities, and managing soil P. Transport controls employ an understanding of loss or transfer mechanisms to avoid P application on areas with a high transport potential. Also, the potential for P transport can be reduced by implementation of conservation practices s...
Torque range of motion in the hand clinic

Abstract Goniometric measurement of passive range of motion is a classic evaluation tool of hand therapy, yet there is no objective quantification of the torques applied from one measurement to the next, or position of the proximal joints during measurement. This paper discusses a method of controlled torque and joint position that has been used experimentally and clinically as a tool for objective assessment of passive range of motion. Case illustrations demonstrate the usefulness of this technique in clinical case management.
Laparoscopic colorectal surgery--are we being honest with our patients?

PURPOSE: A survey was undertaken to assess the impact of laparoscopy on the practice of colorectal surgery. METHODS: A total of 1,520 questionnaires were mailed to all members of the American Society of Colon and Rectal Surgeons; 635 (42 percent) surgeons responded, 50 percent, and indicated that one questionnaire represented their entire group practice. RESULTS: Two hundred seventy-eight (47 percent) respondents currently perform laparoscopic colorectal surgery; 62 percent (171) use the laparoscope for ≤20 percent of their bowel resections. Conversely, only 6 percent (16) use the laparoscope in over 50 percent of resections. The percentage of surgeons who perform various procedures were right colectomy, 78 percent; left colectomy, 57 percent; stoma creations, 52 percent; anterior resection, 44 percent; Hartmann's closure, 42 percent; abdominoperineal resection, 27 percent; rectopexy, 18 percent; and total colectomy, 14 percent. If the preoperative diagnosis is known to be carcinoma, 196 (71 percent) surgeons attempted laparoscopic colorectal surgery, but 55 percent of surgeons (108) operated only for early lesions and 35 percent (68) only for palliation. To enable the procedure to be laparoscopically performed, 87 percent (243) of surgeons stated that they have changed their practice to include routine use of ureteral stents (23 percent), preoperative colonoscopic marking of small lesions (40 percent), or intraoperative colonoscopy. Despite increased use of endoscopy, there were 18 patients in whom the wrong segment of colon was removed. Moreover, nine patients had early local recurrence after resection of colon cancer, nine had early local recurrence after rectal cancer resection, and five had early port-site recurrence. Although 255 (40 percent) surgeons surveyed would themselves undergo laparoscopic colorectal surgery for a rectal villous adenoma, only 38 (6 percent) would have a laparoscopic anterior resection for cancer. CONCLUSIONS: Several important problems exist including early port-site recurrence and a dual surgical standard. Although many surgeons are eager to practice laparoscopic colorectal surgery on their patients with carcinoma, they are reluctant to have the new technique applied to themselves.
Continuous spectrophotometric assays for cytosolic epoxide hydrolase.

Two convenient and sensitive continuous spectrophotometric assays for cytosolic epoxide hydrolase are described. The assays are based on the differences in the ultraviolet spectra of the epoxide substrates and their diol products. The hydrolysis of 1,2-epoxy-1-(p-nitrophenyl)pentane (ENP5) is accompanied by a decrease in absorbance at 302 nm, while the hydration of 1,2-epoxy-1-(2-quinolyl)pentane (EQU5) produces an increase in absorbance at 315.5 nm. The Km, Vmax values for ENP5 and EQU5 with purified mouse liver cytosolic epoxide hydrolase were 1.7 μm, 11,700 nmol/min/mg and 25 μm, 8300 nmol/min/mg, respectively. Both substrates are hydrolyzed significantly faster than trans-stilbene oxide, which is currently the most commonly used substrate for measuring cytosolic epoxide hydrolase activity. No spontaneous hydrolysis of the substrates is detectable under normal assay conditions. The assays are applicable to whole tissue homogenates as well as purified enzyme preparations. p-Nitrostyrene oxide and p-nitrophenyl glycidyl ether were also examined and found to be very poor substrates for cytosolic epoxide hydrolase from mouse liver.
900 EFFECT OF EXOGENOUS GROWTH HORMONE IN PATIENTS WITH THALASSEMIA MAJOR

Exogenous growth hormone (GH) (0.1 U/kg/IM TIW) was administered to 4 female patients with Thalassemia Major (TM) and severe short stature to determine if their growth rate would improve. At the start of the study, all were < 1%ile in height, had a growth rate < 3 cm/yr, bone age < 12 yrs, nl TSH and T4 levels, nl GH response to L-Dopa/glucagon, and had no previous therapy with hormonal agents. After 6 months of GH treatment, Pt.l had an increase in growth rate from 3 to 4.8 cm/yr. Pt. 2 also had an increase in growth rate (5.1 cm/yr); however there was a concurrent advancement in puberty. Pts. 3 and 4 had no improvement in growth velocity. However, pt. 3 was found to have a mildly elevated TSH 3 months after GH was started. The data suggests that treatment with exogenous GH may be associated with an improvement in growth rate in some TM patients.
The Dictionary of Virology, 4th Edition

Rapidly expanding technologies in the field of virology, identification of novel viral agents, and the 2005 report (8th edition) of the International Congress of Taxonomy of Viruses (ICTV) addressing reclassification of several viruses generated the 20% new material in Mahy’s 4th edition of The Dictionary of Virology. The previous edition of this book was published in 2001; the 2009 edition includes recent advancements, such as newly described viruses (e.g., severe acute respiratory syndrome (SARS) human coronavirus, human metapneumoviruses, bocaviruses, and Rabensburg virus), reclassification schemes of viruses (for instance, the unassigned Anellovirus genus), and descriptions of new technologies (e.g., microarray analyses and microRNAs) that have profoundly affected the field of virology. This comprehensive desk reference provides concise definitions of virologic terms; enables quick fact checking; and provides useful, often difficult to find, information—such as the origin of virus names, determination of ICTV-approved virus abbreviations, and locations and sources of viral isolations. An appendix of current ICTV-recognized virus families, subfamilies, genera, and type species is especially useful. However, this reference is limited to viruses infecting vertebrate hosts; thus, it excludes viruses of plants, bacteria, fungi, invertebrates (except for arboviruses that have dual replication cycles within invertebrates and vertebrate hosts) or viruses (the newly described virophages of mimiviruses). The increasing quantity of information about viruses of vertebrates ranging from fish to primates presented the author with considerable space difficulties. He compensated for this situation, however, by citing literature sources at the end of entries for readers seeking more information. Additionally, considerable cross-referencing enhances the utility of the book. On the basis of inclusion of new information in the field and my personal experience with previous editions of The Dictionary of Virology, I highly recommend this volume to students, virologists, microbiologists, and public health professionals interested in viruses of vertebrate hosts.
The Impact of Computer Mediated Communication on the Processes and Outcomes of Negotiated Transfer Pricing

Abstract New communication technologies are offering organizations options that were not previously available. These new opportunities have the potential to impact many aspects of the organization, including coordination and control efforts. Despite a growing literature concerning computer-mediated communication, the basic question of whether the simple switch from written to computer-mediated communication changes behavior still remains unanswered. We argue that advanced information technology has created a frame with enabling and limiting impacts that exists even when the major characteristics are not present. This paper reports the results of a laboratory experiment concerning the effects of communication medium on the process and outcomes of negotiations in a transfer pricing situation. An organizational coordination mechanism and its interactions with communication medium were also examined. Structured negotiations were communicated through written exchanges and through computerized networks where the media richness and technical system capabilities were the same in both media. The negotiation process and outcomes were both measured. The results show that communication medium does effect both the process and outcomes of negotiations, even when media richness and system capabilities are the same in both media. Computer-mediated communication took fewer rounds of negotiation to reach an agreement, leading to an improved process, but had lower outcomes with lower firm profit and lower perceived autonomy. Thus, these results support our argument that medium provides a frame that affects behavior even when the major characteristics of the medium are absent. Further, medium interacts with arbitration, demonstrating the importance of considering other coordination and control mechanisms when examining the impact of medium.
The reformed gallbladder: clinical and roentgen aspects.

Disease of the dilated cystic duct remnant following cholecystectomy has been considered from both the clinical and roentgenological points of view. A recent case has been included as an illustration of the problem.
Crystal structure of Pseudomonas mevalonii HMG-CoA reductase at 3.0 angstrom resolution

The rate-limiting step in cholesterol biosynthesis in mammals is catalyzed by 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, a four-electron oxidoreductase that converts HMG-CoA to mevalonate. The crystal structure of HMG-CoA reductase from Pseudomonas mevalonii was determined at 3.0 angstrom resolution by multiple isomorphous replacement. The structure reveals a tightly bound dimer that brings together at the subunit interface the conserved residues implicated in substrate binding and catalysis. These dimers are packed about a threefold crystallographic axis, forming a hexamer with 23 point group symmetry. Difference Fourier studies reveal the binding sites for the substrates HMG-CoA and reduced or oxidized nicotinamide adenine dinucleotide [NAD(H)] and demonstrate that the active sites are at the dimer interfaces. The HMG-CoA is bound by a domain with an unusual fold, consisting of a central alpha helix surrounded by a triangular set of walls of beta sheets and alpha helices. The NAD(H) is bound by a domain characterized by an antiparallel beta structure that defines a class of dinucleotide-binding domains.
The effect of the α-emitting radionuclide lead-212 on human ovarian carcinoma: A potential new form of therapy

To improve response and survival of patients with ovarian carcinoma noncross-resistant forms of therapy must be developed. α -emitting radionuclides may be therapeutically useful since they can directly ionize with energies of 5 to 9 MeV, penetrate only a few cell diameters, and transfer a high amount of energy. The purpose of this study was to determine the effect of the α -emitter, lead-212 ( 212 Pb), complexed to sulfur in a nude athymic mouse model (NIH:OVCAR-3) containing human ascites and solid epithelial ovarian carcinoma. Thirty-six nude mice 28 to 32 days old were injected with 10 7 to 10 8 carcinoma cells from donor mice. After 4 weeks, six groups of six nu/nu athymic BALB-C mice were intraperitoneally injected with 70, 50, 20, 5 μ Ci of 212 Pb sulfur colloid, sulfur colloid, or saline. Tumor necrosis with a decrease in ascites and a dose-related survival were noted with doses of 50, 20, and 5 μ Ci. With 70 μ Ci acute gastrointestinal toxicity developed. These experiments form the basis for further investigations and the development of α -emitting radiocolloids which may be of therapeutic efficacy in the treatment of intraperitoneal ovarian carcinoma.
Posterior cerebral artery infarction associated with carotid dissection.

Background : Posterior circulation stroke may rarely be associated with occlusive disease in the anterior circulation, such as in the context of a direct (fetal) origin of the posterior cerebral artery (PCA) from the internal carotid artery (ICA), or in the presence of a persistent trigeminal artery. Carotid dissection is an increasingly recognized cause of anterior circulation ischemia. It is possible that in the setting of certain cerebral hemodynamics, embolism from carotid dissection could cause PCA infarction via a patent posterior communicating artery. Case Description : We report the MR and MR angiography findings of cerebral dynamics whereby a patient presents with posterior circulation symptoms from anterior circulation pathology: left ICA dissection with subsequent left PCA territory infarction. Conclusions : Cerebral hemodynamics may allow PCA infarction from carotid disease even in the absence of a fetal PCA origin. This report also broadens the spectrum of stroke associated with carotid dissection.
A practical method for the preparation of protected peptide fragments using the Kaiser oxime resin

Abstract Resin-bound peptides can be cleaved from the Kaiser oxime resin using the tetra-n-butylammonium salts of side-chain protected amino acids to directly provide the α-amino-protected (Boc), side-chain protected peptide. Complete experimental details are provided. The protected peptide fragments can be purified and used for fragment coupling synthetic strategies.
Resolving the justice dilemma by improving the outcomes: The case of employee drug screening

In this paper we seek to accomplish two objectives. First, we review and describe a phenomenon we call the justice dilemma. We argue that workers often perceive valid assessment practices to be unfair. By using these techniques, employers risk incurring hidden costs that are associated with perceived injustice. Thus, it is sometimes impractical to utilize an assessment technique even though the procedure has good validity evidence. Our second purpose is to propose and test one way that organizations can resolve the justice dilemma. We do this in the context of workplace drug screening. We argue that employees are often more tolerant of controversial assessment techniques to the extent that these procedures do not result in particularly negative outcomes. In a field study examining employee reactions to a drug screening program, this proposition was generally supported.
Impact of public reporting and outlier status identification on percutaneous coronary intervention case selection in Massachusetts.

Objectives This study sought to evaluate the impact of public reporting of hospitals as negative outliers on percutaneous coronary intervention (PCI) case-mix selection. Background Public reporting of risk-adjusted in-hospital mortality after PCI is intended to improve outcomes. However, public labeling of negative outliers based on risk-adjusted mortality rates may detrimentally affect hospitals’ willingness to care for high-risk patients. Methods We used generalized estimating equations to examine expected in-hospital mortality rates for 116,227 PCI patients at all nonfederally funded Massachusetts hospitals performing PCI from 2003 to 2010. The main outcome measure was the change in predicted in-hospital mortality rates per hospital after outlier status identification. Results The prevalence-weighted mean expected mortality for all PCI cases during the study period was 1.38 ± 0.36% (5.3 ± 1.96% for all shock or ST-segment elevation myocardial infarction patients, 0.58 ± 0.19% for all not shock, not ST-segment elevation myocardial infarction patients). After public identification as a negative outlier institution, there was an 18% relative reduction (absolute 0.25% reduction) in predicted mortality among PCI patients at outlier institutions (95% confidence interval: −0.04 to −0.46%, p = 0.021) compared with nonoutlier institutions. Throughout the study period, there was an additional 37% relative (0.51% absolute) reduction in the predicted mortality risk among all PCI patients in Massachusetts attributable to secular changes since the onset of public reporting (95% confidence interval: −0.20 to −0.83, p = 0.002). Conclusions The risk profile of PCI patients at outlier institutions was significantly lower after public identification compared with nonoutlier institutions, suggesting that risk-aversive behaviors among PCI operators at outlier institutions may be an unintended consequence of public reporting in Massachusetts.
Synthesis and Characterization of Well-Defined, Regularly Branched Polystyrenes Utilizing Multifunctional Initiators

A series of well-defined, long-branched polystyrenes (PS) of various architectures, but the same overall molecular weight, suited to the systematic study of branching effects, have been synthesized by anionic polymerization and characterized. Three end-branched, star-branched polystyrenes with 6, 9, and 13 end branches were synthesized with a trifunctional organolithium initiator; the synthesis of the 13-end molecule required a recently developed methoxysilyl functionalization and precipitation procedure to remove excess linking agent. In these architectures the number of branch points was fixed at four, while the number of chain ends varied. A 6-end, pom-pom (dumbbell-shaped) PS with two branch points was synthesized with a difunctional organolithium initiator. A regular 6-arm star polystyrene having one branch point was included to provide a comparison among three polymers, each having 6 ends, but having the number of branch points equal to 1, 2, or 4. The intrinsic viscosities and infinite dilution dif...
Cellular and molecular events mediated by docosahexaenoic acid-derived neuroprotectin D1 signaling in photoreceptor cell survival and brain protection

Abstract Deficiency in docosahexaenoic acid (DHA) is associated with impaired visual and neurological postnatal development, cognitive decline, macular degeneration, and other neurodegenerative diseases. DHA is an omega-3 polyunsaturated fatty acyl chain concentrated in phospholipids of brain and retina, with photoreceptor cells displaying the highest content of DHA of all cell membranes. The identification and characterization of neuroprotectin D1 (NPD1, 10R, 17S-dihydroxy-docosa-4Z,7Z,11E,13E,15Z,19Z-hexaenoic acid) contributes in understanding the biological significance of DHA. In oxidative stress-challenged human retinal pigment epithelial (RPE) cells, human brain cells, or rat brains undergoing ischemia-reperfusion, NPD1 synthesis is enhanced as a response for sustaining homeostasis. Thus, neurotrophins, Aβ peptide 42 (Aβ42), calcium ionophore A23187, interleukin (IL)-1β, or DHA supply enhances NPD1 synthesis. NPD1, in turn, up-regulates the antiapoptotic proteins of the Bcl-2 family and decreases the expression of proapoptotic Bcl-2 family members. Moreover, NPD1 inhibits IL-1β-stimulated expression of cyclooxygenase-2 (COX-2). Because both RPE and photoreceptors are damaged and then die in retinal degenerations, elucidating how NPD1 signaling contributes to retinal cell survival may lead to a new understanding of disease mechanisms. In human neural cells, DHA attenuates amyloid-β (Aβ) secretion, resulting in concomitant formation of NPD1. NPD1 was found to be reduced in the Alzheimer's disease (AD) cornu ammonis region 1 (CA1) hippocampal region, but not in other areas of the brain. The expression of key enzymes for NPD1 biosynthesis, cytosolic phospholipase A 2 (cPLA 2 ), and 15-lipoxygenase (15-LOX) was found altered in the AD hippocampal CA1 region. NPD1 repressed Aβ42-triggered activation of pro-inflammatory genes and upregulated the antiapoptotic genes encoding Bcl-2, Bcl-xl, and Bfl-1(A1) in human brain cells in culture. Overall, these results support the concept that NPD1 promotes brain and retina cell survival via the induction of antiapoptotic and neuroprotective gene-expression programs that suppress Aβ42-induced neurotoxicity and other forms of cell injury, which in turn fosters homeostasis during development in aging, as well as during the initiation and progression of neurodegenerative diseases.
On embedding complete graphs into hypercubes

Abstract An embedding of K n into a hypercube is a mapping, gf, of the n vertices of K n to distinct vertices of the hypercube. The associated cost is the sum over all pairs of vertices, v i , v j , i ⩽ j , of the (Hamming) distance between gf ( v i ) and gf ( v j ). Let tf ( n ) denote the minimum cost over all embeddings of K n into a hypercube (of any dimension). In this note we prove that tf ( n ) = ( n − 1) 2 unless n = 4 or 8, in which case tf ( n ) = ( n − 1) 2 − 1. As an application, we use this theorem to derive an alternate proof of the fact that the Isolation Heuristic (and its accompanying variants) for the multiway cut problem of Dahlhaus et al. (1994) are tight for all n . This result also gives a combinatorial justification for the seemingly anomalous improvements that these variants achieve in the cases n = 4 and 8.
High aspirations for the programmable gallery

Computers and network technology could revolutionize how museums display information about space science discoveries. Visualization stations are the core of the programmable gallery. Each of these stations consists of a large graphics display and computer, and a smaller text display and computer.
Can irradiated tumors take NO for an answer

In a recent issue of Molecular Cell , Li et al. (2007) reported that ionizing radiation stabilizes hypoxia-inducible factor 1α (HIF-1α) in normoxic tumor tissues through S-nitrosylation by nitric oxide (NO) generated from neighboring activated macrophages.
Dynamic process of prostate cancer metastasis to bone

Prostate cancer metastasis to the bone occurs at high frequency in patients with advanced disease, causing significant morbidity and mortality. Over a century ago, the "seed and soil" theory was proposed to explain organ-specific patterns of metastases. Today, this theory continues to be relevant as we continue to discover factors involved in the attraction and subsequent growth of prostate cancer cells to the bone. These include the accumulation of genetic changes within cancer cells, the preferential binding of cancer cells to bone marrow endothelial cells, and the release of cancer cell chemoattractants from bone elements. A key mediator throughout this metastatic process is the integrin family of proteins. Alterations in integrin expression and function promote dissociation of cancer cells from the primary tumor mass and migration into the blood stream. Once in circulation, integrins facilitate cancer cell survival through interactions between other cancer cells, platelets, and endothelial cells of the target bone. Furthermore, dynamic changes in integrins and in integrin-associated signal transduction aid in the extravasation of cancer cells into the bone and in expansion to a clinically relevant metastasis. Thus, we will review the critical roles of integrins in the process of prostate cancer bone metastasis, from the escape of cancer cells from the primary tumor, to their survival in the harsh "third microenvironment" of the circulation, and ultimately to their attachment and growth at distant bone sites.
Weakly open quantum dots: magnetotransport spectroscopy and zero-field resistance peaks

The role of the environment on the observation of specific transport properties is discussed for open ballistic quantum dots. The saturation of phase-breaking at temperatures below 1 K is found to be mediated by lead coupling, which is found to affect the nature of the observed zero-field resistance peak. This can generally be attributed to the lead-induced modification of the available density of states in the dot, which is related to the magnetoconductance spectrum. Simulations of the magnetoconductance spectrum demonstrate that averaging the spectrum produces widely varying zero-field-resistance peaks in the same system. The exact nature of the environmental coupling in quantum dots is required to study the non-universal character of transport in these systems.
Supervised pattern recognition for the prediction of contrast-enhancement appearance in brain tumors from multivariate magnetic resonance imaging and spectroscopy

Objective: The purpose of this study was to develop a pattern classification algorithm for use in predicting the location of new contrast-enhancement in brain tumor patients using data obtained via multivariate magnetic resonance (MR) imaging from a prior scan. We also explore the use of feature selection or weighting in improving the accuracy of the pattern classifier. Methods and materials: Contrast-enhanced MR images, perfusion images, diffusion images, and proton spectroscopic imaging data were obtained from 26 patients with glioblastoma multiforme brain tumors, divided into a design set and an unseen test set for verification of results. A k-NN algorithm was implemented to classify unknown data based on a set of training data with ground truth derived from post-treatment contrast-enhanced images; the quality of the k-NN results was evaluated using a leave-one-out cross-validation method. A genetic algorithm was implemented to select optimal features and feature weights for the k-NN algorithm. The binary representation of the weights was varied from 1 to 4bits. Each individual parameter was thresholded as a simple classification technique, and the results compared with the k-NN. Results: The feature selection k-NN was able to achieve a sensitivity of 0.78+/-0.18 and specificity of 0.79+/-0.06 on the holdout test data using only 7 of the 38 original features. Similar results were obtained with non-binary weights, but using a larger number of features. Overfitting was also observed in the higher bit representations. The best single-variable classifier, based on a choline-to-NAA abnormality index computed from spectroscopic data, achieved a sensitivity of 0.79+/-0.20 and specificity of 0.71+/-0.11. The k-NN results had lower variation across patients than the single-variable classifiers. Conclusions: We have demonstrated that the optimized k-NN rule could be used for quantitative analysis of multivariate images, and be applied to a specific clinical research question. Selecting features was found to be useful in improving the accuracy of feature weighting algorithms and improving the comprehensibility of the results. We believe that in addition to lending insight into parameter relevance, such algorithms may be useful in aiding radiological interpretation of complex multimodality datasets.
Trends in the Relationship between Infant Mortality and Socioeconomic Status

Abstract This paper reports some of the results of an ecological analysis of the relationship between infant mortality and economic status in metropolitan Ohio at three points in time (1959–1961, 1969–1971 and 1979–1981). The data presented clearly reveal the adverse mortality consequences of alow economic status. In spite of some remarkable declines in the infant death rate since 1960, most notably in neonatal mortality, the inverse socioeconomic differential in 1980 is as wide as it ever was, and it characterizes both whites and nonwhites and both the neonatal and postneonatal components of infant mortality. Moreover, in sharp contrast to the situation a generation ago, the neonatal death rate has emerged as a major contributor to the overall relationship between socioeconomic status and infant mortality. It is suggested that this situation reflects the failure of recent advances in maternal and infant care programs to reach those lower status members of the society that are most in need of them.
Revisiting Descriptive Representation in Congress: Assessing the Effect of Race on the Constituent–Legislator Relationship

The 113th Congress has a record number of racial and ethnic minorities serving on Capitol Hill. Using the 2008 Cooperative Congressional Election Study (CCES), we examine what this increased descri...
Absorbing-like boundaries for quantum field theoretical grid simulations

Abstract We introduce a computational method that permits us to increase the interaction time for quantum mechanical and quantum field theoretical simulations of multi-particle states on a finite space–time grid. In contrast to the usual approach where the unwanted portion of the wave function close to the grid boundaries is absorbed by a potential with a negative imaginary part, this method is unitary and therefore conserves the norm of the state. This technique is based on assigning particles close to the boundary a larger effective mass (or slower speed of light) such that the particles slow down and cannot re-enter the interaction zone. The method can therefore be applied to multi-particle states for which imaginary potential methods fail.
Movement of added clay through calcareous materials

Abstract A study using Cs-134 tagged sediment suspended in infiltrating water has indicated that clay can move in calcareous materials. The study indicated that the time and conditions under which clay movement is initiated in calcareous materials are functions of the availability of clay for movement, channels or pores for the clay to move through, and the quantity of precipitation available to move the clay.
Esterase A is a proteinase from rat urine that can activate plasminogen.

Abstract A proteinase which can activate human, dog and rat plasminogen to plasmin has been isolated from the urine of female rats, using affinity chromatography on benzamidine-coupled Sepharose. Inhibition by diisopropylfluorophosphate, tosyl- L -lysine chloromethylketone and benzamidine classified the enzyme as trypsin-like. The proteinase has weak activity on α-casein and hemoglobin, but will not lyse fibrin clots. It readily cleaves arginly amides, including synthetic substrates specific for human glandular kallikrein and other serine proteinases. A chromogenic substrate for human urokinase (pyro Glu-Gly-Arg-pNA) is a poor substrate for the rat proteinase. Characteristics of the enzyme, such as its molecular weight (25 900), kinetic parameters and inhibition by aprotinin, indicate that this proteinase is esterase A, described by several investigators. Esterase A is shown not to be a true urinary plasminogen activator but rather is a unique arginine-specific proteinase. Urokinase-like and kallikrein-like activity are part of a broader proteolytic activity displayed by this enzyme.
Triple osteotomy of the innominate bone

In forty-five patients, twenty-three with congenital dislocations and the rest with paralytic or other disturbances, this new displacement osteotomy of the hip joint was done when other iliac osteotomies were considered ineffective. The patients seven to seventeen years old were followed two to ten years. Of the fifty-two procedures, forty were satisfactory. Most of the unsatisfactory results were in cases of myelodysplasia, peroneal atrophy, and cerebral palsy.
Same Setting, Different Norms: Phone Call Beginnings in France and the United States.

French native speakers' reactions to phone calls in the United States are an indication of a difference in the norms of interaction between the two countries. This difference, in turn, is understood when one realizes that the phone call, constituting a speech event, is open to different cultural interpretations, in spite of a similarity in the physical conditions of the interaction between the caller and the answerer. (Sequencing conventional opening; cultural variability; telephone calls; France and United States.)
How we know what the eye and the mind's eye see

Milestones in the history of visual system research are reviewed. The use of computers is discussed. The significance of the studies described is examined. >
Conversion of NDE Inspection Signals into Aural Signals for Enhanced Material Characterization

Nondestructive evaluation (NDE) technologies are often used to characterize materials for quality. Usually they rely on visual interpretation of electronic signals generated from conventional NDE instrumentation [e.g., ultrasonic testing (UT) A-scan trace on an oscilloscope or a Lissajous figure on an eddy current testing (ET) instrument]. In some inspections, such as ultrasonic wall thickness measurement, the signals can be easily interpreted. In many other inspections, however, the signals observed on the oscilloscope have low signal-to-noise and are difficult to visually interpret.
The Long-Term Stability of the Human Gut Microbiota

A low-error 16S ribosomal RNA amplicon sequencing method, in combination with whole-genome sequencing of >500 cultured isolates, was used to characterize bacterial strain composition in the fecal microbiota of 37 U.S. adults sampled for up to 5 years. Microbiota stability followed a power-law function, which when extrapolated suggests that most strains in an individual are residents for decades. Shared strains were recovered from family members but not from unrelated individuals. Sampling of individuals who consumed a monotonous liquid diet for up to 32 weeks indicated that changes in strain composition were better predicted by changes in weight than by differences in sampling interval. This combination of stability and responsiveness to physiologic change confirms the potential of the gut microbiota as a diagnostic tool and therapeutic target.
Selective Depletion of High-Avidity Human Immunodeficiency Virus Type 1 (HIV-1)-Specific CD8+ T Cells after Early HIV-1 Infection

Human immunodeficiency virus type 1 (HIV-1)-specific CD8+ T cells in early infection are associated with the dramatic decline of peak viremia, whereas their antiviral activity in chronic infection is less apparent. The functional properties accounting for the antiviral activity of HIV-1-specific CD8+ T cells during early infection are unclear. Using cytokine secretion and tetramer decay assays, we demonstrated in intraindividual comparisons that the functional avidity of HIV-1-specific CD8+ T cells was consistently higher in early infection than in chronic infection in the presence of high-level viral replication. This change of HIV-1-specific CD8+ T-cell avidity between early and chronic infections was linked to a substantial switch in the clonotypic composition of epitope-specific CD8+ T cells, resulting from the preferential loss of high-avidity CD8+ T-cell clones. In contrast, the maintenance of the initially recruited clonotypic pattern of HIV-1-specific CD8+ T cells was associated with low-level set point HIV-1 viremia. These data suggest that high-avidity HIV-1-specific CD8+ T-cell clones are recruited during early infection but are subsequently lost in the presence of persistent high-level viral replication.
Persistence matters: making the most of chat in tightly-coupled work

How much history of the dialogue should a chat client include? Some chat clients have minimized the dialogue history to deploy the space for other purposes. A theory of conversational coordination suggests that stripping away history raises the cost of conversational grounding, creating problems for both writers and readers. To test this proposition and inform design, we conducted an experiment in which one person instructed another on how to solve a simple puzzle. Participants had chat clients that showed either a single conversational turn or six of them. Having the dialogue history helped collaborators communicate efficiently and led to faster and better task performance. The dialogue history was most useful when the puzzles were more linguistically complex and when instructors could not see the work area. We present evidence of participants adapting their discourse to partially compensate for deficits in the communication media.