cssi/SciSciGPT-SciSciNet huggingface dataset:
Kinetics and specificity of human liver aldehyde dehydrogenases toward aliphatic, aromatic, and fused polycyclic aldehydes.

Human mitochondrial aldehyde dehydrogenase (ALDH-2) has a Km for acetaldehyde that is 900-fold lower than that for the cytosolic isozyme, ALDH-1. An increase in aliphatic aldehyde chain length decreases the ALDH-2 Km by up to 10-fold but decreases that of ALDH-1 by 5 orders of magnitude. As a consequence, the Km of ALDH-1 for decanal is 8 times lower than that of ALDH-2, i.e. 2.9 +/- 0.4 and 22 +/- 3 nM, respectively. Determination of these low Km values required kinetic analysis of the simultaneous enzymatic conversion of two aldehyde substrates, an approach also applied to aromatic and fused polycyclic aldehydes. For most of these substrates, maximum velocities are 5-100 times lower than those for acetaldehyde. Addition of one of these tight-binding, slow-turnover substrates to a reaction mixture containing ALDH, NAD+, and a "reference" aldehyde substrate (e.g. acetaldehyde) blocks the principal (reference) enzymatic reaction temporarily and reversibly. Once the first substrate is converted to product, the enzyme can act on the reference substrate. In terms of apparent affinity and blocking capacity, naphthalene and phenanthrene aldehydes were the most potent effectors. Other aromatic and fused polycyclic and heterocyclic aldehydes, as well as derivatives of coumarin, quinoline, indole, and pyridine, are tight-binding, slow-turnover substrates for ALDH-2 and relatively weak inhibitors of ALDH-1. The hydrophobicity of substituents of benzaldehydes, and particularly of naphthaldehydes, correlates with their binding constants toward ALDH-2. Vitamin A1 aldehydes are specific natural substrates for ALDH-1; at pH 7.5, for all-trans- and 13-cis-retinal, Km = 1.1 and 0.37 micromolar, respectively, and kcat/Km is 50-100 times higher than that for acetaldehyde. At the same time, the retinals are inhibitors of ALDH-2, all-trans-retinal being a particularly potent inhibitor (competitive Ki = 43 nM, noncompetitive Ki = 316 nM). These properties suggest that all-trans-retinal is a possible regulatory compound for ALDH-2 in vivo. The data in general point to specialized roles for both major human liver ALDH isozymes in the oxidation of bulky/hydrophobic natural compounds, with Km values in the low nanomolar range.
Phages that display P-selectin antagonism

Selectins mediate adhesion events among leukocytes, platelets, and endothelial cells. Within the selectin family, P-selectin plays a predominant role in the recruitment of polymorphonuclear neutrophils into inflammatory sites and, thus, represents an important target for future therapies against
Periodontal repair after surgical debridement with and without cartilage allografts

Abstract The effect of a cartilage allograft on healing in intrabony defects treated by open flap curettage was investigated at 130 surgical sites in 4 patients. Thinned mucoperiosteal flaps were elevated and the intrabony defects were debrided. A stem with stainless steel pins was used to measure defect depth at fixed locations adjacent to the root surfaces. The bony defects treated ranged from 0–9 mm with a mean intraosseous depth of 2.4 mm. 62 sites received cartilage implants and 68 sites were treated by surgical debridement only. The flaps were readapted and sutured to the level of the alveolar crest. After 16 weeks the defects were remeasured. Both treatment methods resulted in a mean apical shift of –0.09 mm of the base of the defects that were 3.5 mm in depth. The repair in deeper lesions increased with the number of intrabony walls. Mean pocket depth at flap curettage sites was reduced from 5.4–3.3 mm (P<0.01) at 16 weeks. At sites receiving the cartilage, the mean pocket depth decreased from 5.6–3.6 mm (P<0.01). Pocket reduction resulted from a combination of surgical recession and a mean gain of 1 mm in clinical attachment (P<0.05 for flap curettage sites only). The cartilage implants provided no statistically significant advantage in either bony or soft tissue repair over flap debridement alone. Although bony repair is influenced by depth and configuration of the intrabony defects, significant gains in attachment and reductions in pocket depth may occur independently of changes at the base of the intrabony defects.
Photoswitching HCN Channels in Degenerated Retina Neurons

Some degenerative retinal diseases involve death of rods and cones, while the remaining retinal cells remain intact, yet nonresponsive to light. An azobenzene-photoswitch ion-channel-trans-blocker DENAQ restores retina light sensitivity in mouse model of photoreceptor degeneration (rd1), without affecting wild type (WT) animals. We compared ion currents in retinal ganglion cells (RGCs) of the WT and rd1 mice, and their regulation by light following application of DENAQ. Voltage-gated K-currents were regulated by DENAQ similarly in RGCs of the WT and rd1-retinas (19% vs 21%-increase by 480nm-light). However, DENAQ photosensitized hyperpolarization-activated cyclic-nucleotide-gated (HCN) channels in rd1 RGCs, but not WT retinas. The WT-RGCs revealed mainly fast-activating (tens ms) Ih, while most rd1-RGCs showed a substantial portion of slow Ih (τa>100ms). Illumination produced 21%-increase of Ih (1.3pA/pF at −100mV) within hundreds ms in DENAQ-pretreated (150μM) neurons. Same light in DENAQ-treated WT-RGCs produced no fast changes, while some neurons showed small slow decrease of Ih (<5% developing within 5sec). We hypothesize that slow HCN channels up-regulated in degenerated retina, might be more sensitive to DENAQ than the fast ones in the WT, but do not exclude other targets mediating light-effects on Ih.View Large Image | View Hi-Res Image | Download PowerPoint Slide
Catalytic Hydrogenolysis of Biphenylene with Platinum, Palladium, and Nickel Phosphine Complexes

The catalytic hydrogenolysis of biphenylene was carried out using Pt, Pd, and Ni phosphine complexes under an atmosphere of H2 between 56 and 120 °C. The Pt species Pt(PEt3)3, (PEt3)2Pt(2,2‘-biphenyl), 1, trans-(PEt3)2PtH2, and trans-(PEt3)2Pt(α-biphenyl)H, 4, were all viable catalysts. The resting state species in each case was complex 4. At 80 °C under an atmosphere of H2, 4 reductively eliminates biphenyl and forms trans-(PEt3)2PtH2. Free PEt3 inhibits the rate of reductive elimination from 4 and the overall rate of hydrogenolysis. The novel Pt(IV) dihydride trans,cis-(PEt3)2Pt(2,2‘-biphenyl)H2 was synthesized and characterized by X-ray analysis. trans,cis-(PEt3)2Pt(2,2‘-biphenyl)H2 undergoes unimolecular reductive elimination to give 2. On the basis of these results a catalytic cycle is proposed. A mixture of [(dippe)PtH]2 and (dippe)PtH2 (dippe = bis(diisopropylphosphino)ethane) was also capable of catalyzing the hydrogenolysis of biphenylene under an atmosphere of H2 at 120 °C. The rate of hydrogeno...
Attentional deficits with and without hyperactivity: teacher and peer perceptions.

The present study assessed teacher and peer perceptions of boys classified according to DSM-III criteria for Attention Deficit with Hyperactivity (ADH) and Attention Deficit without Hyperactivity (AD). Teachers completed SNAP checklists (Pelham, Note 1) on all boys in their classrooms (219 boys). Twelve percent fit ADH criteria; less than 5% fit AD criteria. Teacher perceptions were assessed with the Conners Teacher Rating Scale. ADH and AD groups did not differ on the Inattention factor, although the AD group was rated significantly lower than the ADH group on Conduct Problems and Hyperactivity. These profiles were expected on the basis of DSM-III descriptions of ADH and AD; the ADH group seemed to resemble previous research samples of hyperactive children. Classroom peer perceptions, assessed with like-dislike nominations, did not discriminate between diagnostic groups. Both groups were perceived more negatively than the Comparison group, suggesting that both groups are “at risk”.
Acute cold exposure and cognitive function: Evidence for sustained impairment

Several industries experience periods of cold exposure and rewarming throughout the workday but mental performance under these conditions is unknown. A better understanding of cognition during the rewarming phase after cold exposure may help reduce accidents and improve performance. Ten young men (wearing ∼0.1 clo) underwent three consecutive mornings trials where they were exposed to cold air (10°C) and then subsequently rewarmed (25°C air). A computerised test battery was administered during each stage of the protocol to determine working memory, choice reaction time, executive function and maze navigation. Rectal and skin temperature, oxygen consumption and thermal sensation were also measured throughout and showed a typical response. Relative to baseline performance, working memory, choice reaction time and executive function declined during exposure to 10°C, and these impairments persisted 60 min into the recovery period (i.e. once physiological parameters had returned to baseline). Further work is n...
Glucagon Responses of Isolated α Cells to Glucose, Insulin, Somatostatin, and Leptin

To determine whether glucagon suppression by leptin represents a direct effect on α cells rather than an indirect effect mediated via the hypothalamus.
Antigenic Determinants of C3 and C4 Complement Components on Washed Erythrocytes from Normal Persons

Well-washed erythrocytes from normal persons were agglutinated by antisera to C3, C3d, and C4, and this agglutination was specifically inhibited by the corresponding C3 or C4 protein. C3 and C4 antigenic determinants were present on the red blood cells of freshly shed blood promptly anticoagulated with EDTA, heparin, ACD, or CPD, and no significant changes in degree of agglutination were observed on storage of EDTA or CPD blood for two weeks at 4 C. Marked differences in degree of agglutination by anti-C3, anti-C3d, and anti-C4 were observed when erythrocytes of 16 normal persons were assayed, and significant correlations were obtained when the quantitative results with any two antisera were compared. Anti-C3c did not agglutinate erythrocytes from normal persons, suggesting that the C3 antigens detected on normal cells are carried by the C3d fragment. To avoid significant agglutination of the erythrocytes from some normal persons, very dilute preparations of anti-C3, -C3d, and -C4 had to be used for instrumented diagnostic direct antiglobulin tests. Stronger reagents could be used for indirect antiglobulin tests when the result of a suitable control could be subtracted.
Localization in the ground state of a disordered array of quantum rotators

We consider the zero-temperature behavior of a disordered array of quantum rotators given by the finite-volume Hamiltonian: $$H_\Lambda = - \mathop \Sigma \limits_{x \in \Lambda } \frac{{h(x)}}{2}\frac{{\partial ^2 }}{{\partial \varphi (x)^2 }} - J\mathop \Sigma \limits_{\left\langle {x,y} \right\rangle \in \Lambda } \cos (\varphi (x) - \varphi (y))$$ , wherex,y∈Z d , 〈,〉 denotes nearest neighbors inZ d ;J>0 andh={h(x)>0,x∈Z d } are independent identically distributed random variables with common distributiondμ(h), satisfying ∫h −δ dμ(h) 0. We prove that for anym>0 it is possible to chooseJ(m) sufficiently small such that, if 0<J<J(m), for almost every choice ofh and everyx∈Z d the ground state correlation function satisfies $$\left\langle {\cos (\varphi (x) - \varphi (y))} \right\rangle \leqq C_{x,h,J} e^{ - m\left| {x - y} \right|} $$ for ally∈Z d withC x,h,J <∞.
Recurrent pancreatitis caused by pancreatobiliary anomalies in children with annular pancreas.

Abstract Purpose Annular pancreas (AP) is usually associated with duodenal obstruction in neonates. Pancreatitis with AP occurs frequently in adults but is rare in children. This article describes pancreatitis in children with AP and pancreatobiliary anomalies and its surgical treatment. Patients and Methods Six children who underwent duodenal bypass for AP subsequently developed recurrent pancreatitis. Three had trisomy 21. Duodenoduodenostomy had been performed in 5 patients and gastrojejunostomy in 1 patient for neonatal duodenal obstruction. We reviewed overall management, imaging, and surgical treatment in these children. Results All children subsequently complained of recurrent abdominal pain. Pancreatitis developed in 6 children, and magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography (ERCP) revealed associated pancreatobiliary anomalies such as pancreas divisum, pancreatobiliary malunion, choledochocele, and intraluminal duodenal diverticulum. In 5 cases, surgery for recurrent or chronic pancreatitis was performed. The range of follow-up was 11 to 54 months, and all children who underwent surgery had excellent results. Conclusions Children with AP occasionally require reoperation for recurrent pancreatitis because of associate pancreatobiliary anomalies. Magnetic resonance cholangiopancreatography and ERCP provide excellent images of pancreatobiliary anomalies. Intraoperative cholangiopancreatography is also essential for accurate depiction of the ductal structure and selection of the appropriate surgical procedure.
Increased plasma and tissue MMP levels are associated with BCSFB and BBB disruption evident on post-contrast FLAIR after experimental stroke

In this study, we examined the relationship between tissue and blood levels of matrix metalloproteinase (MMP)-2 and MMP-9 through gelatin zymography at multiple time points after experimental stroke. We additionally investigated the association between these levels and the evidence of blood-cerebrospinal fluid (CSF) barrier (BCSFB) and blood-brain barrier (BBB) disruption on post-contrast fluid-attenuated inversion-recovery (FLAIR) imaging. Increased plasma MMP-9 was associated with BCSFB disruption at 1h post-reperfusion. Ventricular enhancement ipsilateral to the stroke was 500+/-100%, significantly higher than sham, 24, and 48 h groups. Increased tissue MMP-2 and MMP-9 were associated with BBB disruption at 48 h post-reperfusion. Parenchymal enhancement was 60+/-20% for a volume equivalent to 260+/-80 mm(3). Although the percent enhancement was comparable across groups, the volume of enhancing lesion was significantly higher at 48 h (260+/-80 mm(3), 100%) in comparison to 1 h (8+/-3 mm(3), 3%) and 24 h (51 mm(3), 18%). These findings support the use of imaging markers of BCSFB and BBB status as indirect measures of MMP regulation in the blood and brain tissue. The methods presented herein should be useful in understanding the link between MMPs, barrier integrity, and subsequent hemorrhagic transformation.
Transcription factor IID in the Archaea: sequences in the Thermococcus celer genome would encode a product closely related to the TATA-binding protein of eukaryotes

The first step in transcription initiation in eukaryotes is mediated by the TATA-binding protein, a subunit of the transcription factor IID complex. We have cloned and sequenced the gene for a presumptive homolog of this eukaryotic protein from Thermococcus celer, a member of the Archaea (formerly archaebacteria). The protein encoded by the archaeal gene is a tandem repeat of a conserved domain, corresponding to the repeated domain in its eukaryotic counterparts. Molecular phylogenetic analyses of the two halves of the repeat are consistent with the duplication occurring before the divergence of the archael and eukaryotic domains. In conjunction with previous observations of similarity in RNA polymerase subunit composition and sequences and the finding of a transcription factor IIB-like sequence in Pyrococcus woesei (a relative of T. celer) it appears that major features of the eukaryotic transcription apparatus were well-established before the origin of eukaryotic cellular organization. The divergence between the two halves of the archael protein is less than that between the halves of the individual eukaryotic sequences, indicating that the average rate of sequence change in the archael protein has been less than in its eukaryotic counterparts. To the extent that this lower rate applies to the genome as a whole, a clearer picture of the early genes (and gene families) that gave rise to present-day genomes is more apt to emerge from the study of sequences from the Archaea than from the corresponding sequences from eukaryotes.
A sulphite-oxidase-deficient rat model: metabolic characterization.

Rats were made deficient in sulphite oxidase by the administration of a high-tungsten/low-molybdenum regimen as described first by Johnson et al. (J. biol. Chem. 1974, 249, 859). The specific protocol used resulted initially in an exponential decrease in hepatic sulphite-oxidase activity with a half-life of 4 days and an eventual steady-state enzyme level approximately 1% of the normal adult level. A clear inverse relationship was demonstrated between hepatic sulphite-oxidase activity and tissue and/or urine concentrations of sulphite and of two sulphite metabolites, S-sulphonate (RS-SO3−) and and inorganic thiosulphate (S2O3− −). As rat tissues became depleted of sulphite-oxidase activity, sulphite produced endogenously from the catabolism of sulphur-containing amino acids gradually became apparent. The first chemical evidence of an increased systemic concentration of sulphite occurred when the sulphite-oxidase activity had declined to about 7% of the normal adult level; at this point, slight but significant increases in urinary S2O3− − and RS-SO3− concentrations were observed. The additional decline of sulphite oxidase to 1% of the normal level resulted in substantial increases in the excretion of both of these metabolites. In addition, large increases in aortic RS-SO3− concentrations relative to pretreatment levels and smaller increases in plasma and pinna RS-SO3− concentrations were observed as the rats approached a steady-state enzyme level. The ability of these sulphite-oxidase-deficient rats (1% of normal activity) to clear sulphite following intragastric sulphite administration was compared with that of normal rats. The results showed that deficient rats were much less efficient at this process and thus required lower exogenous doses to produce equivalent systemic exposures.
BMS1 Is Mutated in Aplasia Cutis Congenita

Aplasia cutis congenita (ACC) manifests with localized skin defects at birth of unknown cause, mostly affecting the scalp vertex. Here, genome-wide linkage analysis and exome sequencing was used to identify the causative mutation in autosomal dominant ACC. A heterozygous Arg-to-His missense mutation (p.R930H) in the ribosomal GTPase BMS1 is identified in ACC that is associated with a delay in 18S rRNA maturation, consistent with a role of BMS1 in processing of pre-rRNAs of the small ribosomal subunit. Mutations that affect ribosomal function can result in a cell cycle defect and ACC skin fibroblasts with the BMS1 p.R930H mutation show a reduced cell proliferation rate due to a p21-mediated G1/S phase transition delay. Unbiased comparative global transcript and proteomic analyses of ACC fibroblasts with this mutation confirm a central role of increased p21 levels for the ACC phenotype, which are associated with downregulation of heterogenous nuclear ribonucleoproteins (hnRNPs) and serine/arginine-rich splicing factors (SRSFs). Functional enrichment analysis of the proteomic data confirmed a defect in RNA post-transcriptional modification as the top-ranked cellular process altered in ACC fibroblasts. The data provide a novel link between BMS1, the cell cycle, and skin morphogenesis.
Anaphylaxis due to airborne exposure to latex in a primigravida.

LATEX sensitivity in the surgical population has been well-described, including anaphylactic reactions from contact with latex products in the operating suite, 1 The use of powdered latex examination gloves is associated with increased levels of latex particles in the air, 5,6 Exposure to airborne latex antigen can trigger allergic reactions in sensitized individuals, 5,7,8 We describe a case of a parturient with known latex sensitivity who had an anaphylactic reaction in the obstetric triage room after unintentional exposure to airborne latex particles. This reaction precipitated fetal distress and the potential need for emergency cesarean delivery.
Causes and consequences of the autoimmune lymphoproliferative syndrome

AbstractAutoimmune lymphoproliferative syndrome (ALPS) is the first autoimmune hematological disease whose genetic basis has been defined. It is a disorder of apoptosis in which the inability of lymphocytes to die leads to lymphadenopathy, hypersplenism, and autoimmune cytopenias of childhood onset. More than 200 ALPS patients have been studied over the last 15 years and followed by our colleagues and ourselves at the Clinical Center of the National Institutes of Health. Based upon this experience we have determined that patients with germline mutations of the intracellular domain of Fas protein, the most frequent single genetic cause of ALPS, have a significantly increased risk of developing Hodgkin and non-Hodgkin lymphoma (NHL), underscoring the critical role played by cell surface receptor-mediated apoptosis in eliminating redundant proliferating lymphocytes with autoreactive and oncogenic potential. The major determinants of morbidity and mortality in ALPS are the severity of the autoimmune disease, ...
Tracking the Footprints of Anonymous Defamation in Cyberspace: A Review of the Law and Technology

AbstractThe rise of the Internet has made anonymous defamation a reality. Tracking the footprints of anonymous defamation in cyberspace can be difficult from a legal and technological perspective. Legally, the injured party may need to pursue two defendants - the website that hosted the defamatory statement and the anonymous defamer. This process can be taxing from both an economic and personal perspective, and in some cases will lead to a dead end due to technological roadblocks. One of the primary reasons that the footprints of anonymous defamation can lead to a dead end is that the IP address logs may have been purged. Currently there are no regulations or standards in the industry requiring IP address logs to be preserved for a minimum time period. This article addresses the legal and technological roadblocks that can lead to anonymous defamation and suggests regulatory systems for IP address logs as a means of combating unacceptable anonymous behavior on the Internet.
Structure of correlation functions

Experimental determinations of correlation functions typically involve events of differing particle number. In order to interpret such data, it is important to relate these measurements to fixed-number correlations. We exhibit the total correlation function in terms of fixed {ital n} correlations and fluctuations with respect to the average. We note that moments, constructed as integrals of the appropriate correlation functions, can be dominated in the case of broad distributions by cumulant moments constructed from single-particle density fluctuations.
The role of the pediatric nurse practitioner in a neonatal unit.

A pediatric nurse practitioner was given responsibility for a nursery. Her major responsibilities included: (1) daily chart and infant rounds, (2) initial physical examinations, (3) rounds with mothers, and (4) daily report to the physician on the condition and problems in her nursery. Over a one-year period of time, the PNP detected 20 serious problems, such as significant jaundice, sepsis, tachypnea, hypoglycemia, and two major congenital anomalies. The accuracy of the physical examination by the PNP was compared with that of the physician. In 72% of cases, the assessment of the PNP was essentially the same as that of the physician; in the remaining 28% the differences in diagnosis were minor and related to the timing of the examination. A telephone interview of a random sample of mothers showed that mothers under the care of the PNP had received more instructions on infant care; an 81% return of the infants to the clinic was achieved. The pediatric residents approved the participation of the PNP in the nursery. It is concluded that there is a useful role for the PNP in a neonatal unit.
Inhibition of anaerobic digestion process: A review

Anaerobic digestion is an attractive waste treatment practice in which both pollution control and energy recovery can be achieved. Many agricultural and industrial wastes are ideal candidates for anaerobic digestion because they contain high levels of easily biodegradable materials. Problems such as low methane yield and process instability are often encountered in anaerobic digestion, preventing this technique from being widely applied. A wide variety of inhibitory substances are the primary cause of anaerobic digester upset or failure since they are present in substantial concentrations in wastes. Considerable research efforts have been made to identify the mechanism and the controlling factors of inhibition. This review provides a detailed summary of the research conducted on the inhibition of anaerobic processes. The inhibitors commonly present in anaerobic digesters include ammonia, sulfide, light metal ions, heavy metals, and organics. Due to the difference in anaerobic inocula, waste composition, and experimental methods and conditions, literature results on inhibition caused by specific toxicants vary widely. Co-digestion with other waste, adaptation of microorganisms to inhibitory substances, and incorporation of methods to remove or counteract toxicants before anaerobic digestion can significantly improve the waste treatment efficiency.
Effects of dietary technical pentachlorophenol exposure on T cell, macrophage and natural killer cell activity in C57B1/6 mice

Abstract The effects of technical grade pentachlorophenol (T-PCP) exposure on several immunological parameters were examined in adult C57B1/6 mice following eight weeks of dietary exposure. Immune function tests included mitogen-induced lymphocyte blastogenesis, mixed lymphocyte reactivity (proliferation and cytotoxicity), spontaneous and boosted levels of natural killer (NK) cytotoxicity, and phagocytic activity of resident, thioglycollate-induced, and P815-tumor activated peritoneal macrophages. Thymic and splenic weights, spleen cellularity, percentages of splenic T and B cells, and bone marrow cellularity were also determined. The only statistically significant functional alteration observed in T-PCP exposed mice in these studies was a reduction in the lymphoproliferative response in mixed lymphocyte culture which occurred in the absence of any apparent effect on the generation of cytotoxic cells. Mitogen responses, NK cytotoxicity and macrophage phagocytosis were unaltered by exposure to T-PCP. No changes were observed in spleen or thymus weights or in spleen or bone marrow cellularity. A dose-responsive trend toward reduced T cell and increased B cell percentages in the spleen of T-PCP exposed mice was noted. The apparent functional resistance of T cells, macrophages, and NK cells to T-PCP is in contrast to the marked sensitivity of the humoral immune response to T-PCP induced suppression. The results are discussed in relation to the dioxin contaminants present in T-PCP.
New supersymmetric σ-models with Wess-Zumino terms

Abstract We construct new superfields and σ -models with (4,4) and (2,2) supersymmetry. These lead to new metrics that include examples of manifolds with two complex structures that neither commute nor anticommute. We also consider the analogous issues in euclidean supersymmetry, and find the curious result that we are naturally led to indefinite signature σ -model metrics.
Rain retrieval using the 183 GHz absorption lines

High spatial resolution AMSU opaque channels are used to retrieve rain rates and classify precipitation types. The retrieval scheme (183-WSL) consists of two fast algorithms, one for land and the other for sea surface, that use the water strong lines at 183.31 GHz to infer rain rate amounts based on a series of thresholds calculated to remove the condensed water vapor effect and discriminate between convective and stratiform pixels. The reported results show the sensitivity of the technique to detect deep convective clouds and to measure light-rain stratiform systems. This latter fact recommends its application particularly over mid-latitude basins where persistent light rains cause intense run-off episodes. Other studies are planned to apply the method at high latitudes where the atmospheric humidity is mainly located within the surface layers and appropriate correction coefficients need to be found.
Dehydroepiandrosterone sulphate: diabolical hormone or epiphenomenon in aneurysmal subarachnoid hemorrhage?

Inflammation is purported to play an important role in the clinical course of subarachnoid hemorrhage. The current study by Hollig et al. entails using dehydroepiandrosterone sulfate, a hormone that inhibits key inflammatory pathways, as a predictor of functional outcome in these patients.
The fast discrete Radon transform. I. Theory

An inversion scheme for reconstruction of images from projections based on the slope-intercept form of the discrete Radon transform is presented. A seminal algorithm for the forward and the inverse transforms proposed by G. Beylkin (1987) demonstrated poor dispersion characteristics for steep slopes and could not invert transforms based on nonlinear slope variations. By formulating the computation of a discrete computation of the continuous Radon transform formula, the authors explicitly derive fast generalized inversion methods that overcome the original shortcomings. The generalized forward (FRT) and inverse (IFRT) algorithms proposed are fast, eliminate interpolation calculations, and convert directly between a raster scan grid and a rectangular/polar grid in one step. >
Sterol Regulatory Element Binding Protein Is a Principal Regulator of Anaerobic Gene Expression in Fission Yeast

Fission yeast sterol regulatory element binding protein (SREBP), called Sre1p, functions in an oxygen-sensing pathway to allow adaptation to fluctuating oxygen concentrations. The Sre1p-Scp1p complex responds to oxygen-dependent sterol synthesis as an indirect measure of oxygen availability. To examine the role of Sre1p in anaerobic gene expression in Schizosaccharomyces pombe, we performed transcriptional profiling experiments after a shift to anaerobic conditions for 1.5 h. Of the 4,940 genes analyzed, expression levels of 521 (10.5%) and 686 (13.9%) genes were significantly increased and decreased, respectively, under anaerobic conditions. Sre1p controlled 68% of genes induced > or = 2-fold. Oxygen-requiring biosynthetic pathways for ergosterol, heme, sphingolipid, and ubiquinone were primary targets of Sre1p. Induction of glycolytic genes and repression of mitochondrial oxidative phosphorylation genes largely did not require Sre1p. Using chromatin immunoprecipitation, we demonstrated that Sre1p acts directly at target gene promoters and stimulates its own transcription under anaerobic conditions. sre1+ promoter analysis identified two DNA elements that are both necessary and sufficient for oxygen-dependent, Sre1p-dependent transcription. Interestingly, these elements are homologous to sterol regulatory elements bound by mammalian SREBP, highlighting the evolutionary conservation between Sre1p and SREBP. We conclude that Sre1p is a principal activator of anaerobic gene expression, upregulating genes required for nonrespiratory oxygen consumption.
An empirical study of Conserved Self Pattern Recognition Algorithm: Comparing to other one-class classifiers and evaluating with random number generators

Early work has demonstrated that Conserve Self Pattern Recognition Algorithm (CSPRA) produces promising performance in the field of anomaly detection. This paper further extends the applications of CSPRA to Fisher's Iris data, Indian Telugu data and Wisconsin breast cancer data. A formal description of the differences between the two detection strategies (Classical CSPRA and Selective CSPRA) is given and the results show that Selective CSPRA performs better for the tested data. The comparative study of CSPRA to other one-class classifiers (NSA, V-detector and One-class SVM) shows that the performance of the CSPRA is obviously better. This paper also investigates the influence of various random number generators on the performance of the CSPRA and NSA. Our experiments indicates that non-uniform random number generators tend to produce worse performance than uniform random number generators and quasi-random number generator has the potential to enhance the system performance compared to other uniform random number generators.
Fumonisin in tortillas produced in small-scale facilities and effect of traditional masa production methods on this mycotoxin.

Four small tortilla plants were visited in Cameron County, Texas, where observations were made on their production methods. Samples of liquids and solids were collected at each stage of the nixtamalization process, and the pH was recorded. Samples were analyzed for fumonisin B1 (FB1) using an immunoaffinity column/HPLC method chosen for its sensitivity for FB1. It was found that production methods were highly variable among the producers visited, with major differences particularly in the amount of lime added and boiling times. As reported by others working in Mexico and Central America, FB1 was found in some tortillas. This led to studies of the effects of the various recipes and across a greater range of initial FB1 concentration/damaged corn than has typically been reported. Five initial concentrations of FB1 were tested using irradiated corn kernels inoculated with Fusarium verticillioides MRC 826 as the source of FB1. The amount of FB1 detected in the masa and tortillas decreased as the concentration...
Expression of stimulated by retinoic acid gene 8 (Stra8) in spermatogenic cells induced by retinoic acid: an in vivo study in vitamin A-sufficient postnatal murine testes.

Vitamin A is required for male fertility and normal spermatogenesis. Retinoic acid (RA), an active metabolite of vitamin A, is necessary for spermatogonial maturation and proper entry of germ cells into meiotic prophase in the postnatal testes. The expression of Stra8, which is essential for successful meiosis in both male and female gonads and normal spermatogenesis, is directly related to the availability of RA. This study examined the developmental expression pattern of Stra8 transcript in both male and female gonads, provided specific cellular localization of STRA8 protein in the postnatal and adult testis, and investigated RA actions in adult germ cells in a vitamin A-sufficient condition. The peak of Stra8 mRNA expression coincided with the onset of meiosis in postnatal testes. STRA8 protein was detected in gonocytes as early as 5 days postpartum. The expression of STRA8 protein in the neonatal testes was not uniform among spermatogonia, perhaps heralding the asynchronous beginning of spermatogenesis. In adult testes, the highest level of Stra8 mRNA and protein was found in seminiferous epithelial stages VI–VIII. STRA8 protein was localized to some type A and B spermatogonia, preleptotene spermatocytes, and early leptotene spermatocytes. In the vitamin A-sufficient adult testes, RA but not retinol acetate stimulated Stra8 mRNA expression. STRA8 protein expression in adult spermatogonia was induced by RA stimulation, suggesting its role in spermatogonial differentiation. Retinoic acid also increased the number of preleptotene spermatocytes exhibiting 5-bromo-2-deoxyuridine incorporation, indicating a more synchronized premeiotic DNA replication.
Parallel optical interconnection network for address transactions in large-scale cache coherent symmetric multiprocessors

The authors address the primary limitation of bandwidth demands for address transaction in future cache coherent symmetric multiprocessors (SMPs). As a solution, the authors propose a scalable address subnetwork called symmetric multiprocessor network (SYMNET) in which address requests and snoop responses of shared memory multiprocessors are implemented optically. As the address phase of the transaction is linked to the address bandwidth, which is the major bottleneck in SMPs, they focus only on the address subnetwork in this paper. SYMNET has the capability to pipeline address requests from successive processors, which results in increasing the available address bandwidth and lowering the latency of the network. An optical token is implemented to achieve mutual exclusion to the shared channel. This enables collisionless broadcast of multiple address requests. The simultaneous insertion of multiple address requests into the address subnetwork complicates cache coherence. A modified coherence protocol, called COSYM, was introduced to solve the coherence problem. The authors evaluated SYMNET with a subset of Splash-2 benchmarks running from 4-32 processors. Their simulation studies have shown 10%-67% improvement in execution time for various applications. It is also shown that the average latency for a transaction to complete using COSYM was 85% better than the electrical case. An overview of the proposed optical implementation of SYMNET is presented along with the theoretical power budget and bit-error rate analysis. This analysis shows that SYMNET can scale up to hundreds of processors while still using fast snoopy-based cache coherence protocols and that additional performance gains may be attained with further improvement in optical device technology.
Data fusion: color edge detection and surface reconstruction through regularization

Data fusion provides tools for solving problems which are characterized by distributed and diverse information sources. In this paper, the authors focus on the problem of extracting features such as image discontinuities from both synthetic and real images. Since edge detection and surface reconstruction are ill-posed problems in the sense of Hadamard, Tikhonov's regularization paradigm is proposed as the basic tool for solving this inversion problem and restoring well-posedness. The proposed framework includes: (1) a systematic view of oneand two-dimensional regularization; (2) extension of the standard Tikhonov regularization method by allowing space-variant regularization parameters; and (3) further extension of the regularization paradigm by adding multiple data sources to allow for data fusion. The theoretical approach is complemented by developing a series of algorithms, then solving the early vision problems of color edge detection and surface reconstruction. An evaluation of these methods reveals that this new analytical data fusion technique output is consistently better than each of the individual RGB edge maps, and noisy corrupted images are reconstructed into smooth noiseless surfaces.
Fractal dimension estimation using continuous alternating sequential filter pyramid

One of the basic characteristics of a fractal is its dimension. Estimates of the dimension tend to be very inaccurate, as data size is reduced. This paper presents a novel method for fractal dimension estimation based on the use of continuous pyramids of alternative sequential filters (CASF). The method assumes only the self-similarity property of fractals. It was tested over synthetic images and results are presented. Performance of CASF was compared to that of the power spectra method and the wavelet method for large size images (512/spl times/512). Results show that CASF yields much more accurate estimates than the other two methods. When applied to small images, (16/spl times/16) it was observed that the accuracy of the method was still comparable to that obtained with large images.
Merging taxonomies under RCC-5 algebraic articulations

Taxonomies are widely used to classify information, and multiple (possibly competing) taxonomies often exist for the same domain. Given a set of correspondences between two taxonomies, it is often necessary to "merge" the taxonomies, thereby creating a unified taxonomy (e.g., that can then be used by data integration and discovery applications). We present an algorithm for merging taxonomies that have been related using articulations given as RCC-5 constraints. Two taxa N and M can be related using (disjunctions of) the five base relations in RCC-5: N a M; N -- M; N -- M; N -- M (partial overlap of N and M); and N ! M (disjointness: N ) M = O). RCC-5 is increasingly being adopted by scientists to specify mappings between large species taxonomies. We discuss the properties of the proposed merge algorithm and evaluate our approach using real-world biological taxonomies.
VACUUM THERMIONIC ENERGY CONVERTER

Abstract The design and construction of a small-sized vacuum thermionic converter that can generate a watt or more of electrical power are described briefly. The converter is operated by applying heat to the external surface of one electrode. The interior surface of this hot electrode operates in a vacuum and is coated so that it is capable of emitting copious numbers of electrons. The other electrode has a coating on its interior surface that can provide a low anode work function so as to increase the energy available to an external load. The output of the converter increases as the temperature of the emitter is increased and as the electrode spacing is decreased. At an emitter temperature of 1100°C, an output of 1 W/cm 2 and an efficiency of 4·5 per cent have been attained. In practical applications heating can be accomplished by the use of chemical fuel, solar radiation, or nuclear energy.
Measuring the Effect of Structural Change on Long-Term Public Expenditure Growth: the United States, 1929 to 1981

This article presents a methodology for analyzing public expenditure growth to test for structural change. It subjects a version of Peacock and Wiseman's displacement hypothesis to a test based on the idea that the hypothesis involves a structural break. The method is based on a conventional model of the determination of government expenditures as applied to the United States for the period 1929 to 1981. First, the authors fit the equation for 1929 to 1981 (the entire period), for 1929 to 1945 (the early period), and for 1946 to 1981 (the later period). Second, they employ a test of structural stability between the early and later periods. Because this test is signifi cant, the authors then re-estimate the model for the entire period using an intercept shift dummy and coefficient shift dummies, one for each independent variable, for the later period Because the result is ambiguous, the authors take the fourth step and use the early period regression model to first forecast later period values of the depen...
The Frame Game

In this article, the authors explore framing, a non-multiplicative technique commonly employed by students as they construct similar shapes. When students frame, they add (or subtract) a “border” of fixed width about a geometric object. Although the approach does not yield similar shapes in general, the mathematical underpinnings of framing are noteworthy. Using Interactive Geometry Software (IGS), teachers can explore mathematics behind the framing technique in greater depth while addressing student misconceptions and over- generalizations associated with the approach in classroom settings.
In Vitro Cell Adhesion and Detachment Behavior for Various Biomaterial Substrates

Cell-biomaterial interactions for different material compositions were evaluated through quantitative examination of in vitro cell spreading behavior and shear-induced cell detachment. Biomaterial substrates consisted of identically prepared, well characterized bulk samples of implant grade cp Ti, Ti-6AI-4V, and Synamel. 3T3 fibroblasts were seeded on the substrate surfaces and incubated for 2 hours. Adherent cell morphology was then examined using scanning electron microscopy and digital image analysis. The cell detachment response was measured using a parallel plate flow chamber. When categorized according to observed cell morphology, projected cell areas were found to be lognormally distributed for all biomaterials and ln(cell area) was significantly greater for Synamel, while no difference existed between cp Ti and Ti-6AI-4V. In addition, the average post-shear fraction of adherent cells was significantly greater for Synamel substrates, as compared to cp Ti and Ti-6AI-4V substrates. The results from this study indicate that in vitro cell adhesion and detachment behavior are measurably influenced by biomaterial substrate composition.
Towards a Geocentric Framework of Organizational Form: A Holistic, Dynamic and Paradoxical Approach

Despite its increasing importance to the research and practice of organizational management, there is no consensus on how to describe, explain and prescribe network as an organizational form. Based upon the evidence of the Chinese network form within its institutional and cultural contexts, this paper seeks to make three contributions. First, it describes network as a unique form, different from other organizational forms and thus needing a new perspective. Second, it explains network form from a holistic, dynamic and paradoxical perspective by synthesizing economic, social and psychological rationalities. Third, it prescribes the ideal-typical network form by offering a geocentric framework of organizational form which is neither culture-blind (under-embedded) nor culture-bounded (over-embedded).
Calculation of weight vectors for wideband beamforming using Graphics Processing Units

In order to be viable for use in communication and radar systems, wideband beamforming requires the calculation of filter coefficients to be performed quickly so as to avoid undesirable latency in the system. This paper provides a quick introduction to the method of least-squares wideband beamforming and discusses the use of General Purpose computation on Graphics Processing Units (GPGPU) for acceleration of the computations associated with it. Through a simulation case study the authors demonstrate both the computational advantages offered by the use of GPGPU in wideband beamforming applications and the increasing ease with which GPGPU can be used.
Object segmentation by top-down processes

In cluttered scenes, some object boundaries may not be marked by image cues. In such cases, the boundaries must be dened top-down as a result of object recognition. Here we ask if observers can retain the boundaries of several recognized objects in order to segment an unfamiliar object. We generated scenes consisting of neatly stacked objects, and the objects themselves consisted of neatly stacked colored blocks. Because the blocks were stacked the same way within and across objects, there were no visual cues indicating which blocks belonged to which objects. Observers were trained to recognize several objects and we tested whether they could segment a novel object when it was surrounded by these familiar, studied objects. The observer’s task was to count the number of blocks comprising the target object. We found that observers were able to accurately count the target blocks even when the target was surrounded by up to four familiar objects. These results indicate that observers can use the boundaries of recognized objects in order to accurately segment, top-down, a novel object.