cssi/SciSciGPT-SciSciNet huggingface dataset:
What is Where and Why it is Important

The paper by Devlin and Poldrack entitled ‘In praise of Tedious Anatomy’ deals with an increasingly important topic. Namely, how do we effectively communicate, with appropriate accuracy and precision, the ‘where’ of our measurements? They make cogent arguments for the use of anatomical maps to reference the location of functionally active regions of brain as measured with fMRI. We agree with this premise and would like to amplify further (with some additional suggestions) the rationale for equating functional measures with observations about structure. But before we do that, it might be useful to first generalize this issue, as one that pertains to 1) comparing data collected across multiple subjects, modalities, experiments and laboratories and 2) integrating this data as a comprehensive whole. Specifying the site of activation, in anatomic terms, is intended (in part) to provide the ability to compare and contrast different studies. The notion of an atlas is, among other things, to help with this localization. Unfortunately many anatomic terms are sometimes interpreted variably and the boundaries of anatomic regions are sometimes in dispute. Given the mostly descriptive history of anatomy, its application, in a traditional sense, to modern volumetric MRI surveys of the brain sometimes produces more problems than it solves. Atlases such as the (Talairach and Tournoux, 1988) are woefully inadequate as an anatomic reference but did encourage the use and further development of spatial normalization schemes to reduce size and shape variability of brains. Other atlases such as (Ono et al., 1990) and (Duvernoy, 1991, Schleicher et al., 2005) provide far more complete and detailed delineations but either do not provide any principles or algorithms for spatial normalization or Cartesian coordinate systems. And finally, the question of how a single brain based atlas can represent a population is rarely argued anymore.
Associations Between Suicidal High School Students’ Help-Seeking and Their Attitudes and Perceptions of Social Environment

Suicide is a leading cause of death among adolescents, many of whom fail to disclose suicide concerns to adults who might help. This study examined patterns and predictors of help-seeking behavior among adolescents who seriously considered suicide in the past year. 2,737 students (50.9 % female, 46.9 % male; racial distribution 79.5 % Caucasian, 11.9 % Hispanic/Latino, and 3.6 % Black/African-American) from 12 high schools in rural/underserviced communities were surveyed to assess serious suicide ideation (SI) in the past year, disclosure of SI to adults and peers, attempts to get help, attitudes about help-seeking, perceptions of school engagement, and coping support. Help-seeking was defined as both disclosing SI to an adult and perceiving oneself as seeking help. The relationship between adolescents’ help-seeking disclosure and (1) help-seeking attitudes and (2) perceptions of social resources was examined among suicidal help-seeking youth, suicidal non-help-seeking youth, and non-suicidal youth. Of the 381 (14 %) students reporting SI, only 23 % told an adult, 29 % sought adult help, and 15 % did both. Suicidal help-seekers were similar to non-suicidal peers on all measures of help-seeking attitudes and social environment perceptions. Positive attitudes about help-seeking from adults at school, perceptions that adults would respond to suicide concerns, willingness to overcome peer secrecy requests, and greater coping support and engagement with the school were associated with students’ increased disclosure of SI and help-seeking. This study supports prevention strategies that change student norms, attitudes and social environments to promote help-seeking among adolescents with SI. Promising intervention targets include increasing students’ perceptions of the availability and capability of adults to help them, and strengthening students’ understanding of how existing resources can help them cope.
Causes and risk factors for 30-day unplanned readmissions after lumbar spine surgery.

STUDY DESIGN Retrospective review of a prospective cohort. OBJECTIVE To determine the incidence, causes, and risk factors for 30-day unplanned readmissions after lumbar spine surgery. SUMMARY OF BACKGROUND DATA The rising costs associated with lumbar spinal surgery have received national attention. Recently, the government has chosen to target 30-day readmissions as a quality measure. Few studies have specifically analyzed the incidence, causes, and risk factors for readmission in a multicenter patient cohort. METHODS A large, multicenter clinical registry was queried for all patients undergoing lumbar spine surgery in 2012. Current Procedural Terminology codes were used to select patients undergoing lumbar discectomy, laminectomy, anterior and posterior fusions, and multilevel deformity surgery. Thirty-day readmissions rates and causes were identified and analyzed. Univariate and multivariate logistic regression analyses were used to identify patient characteristics, comorbidities, and operative variables predictive of readmission. RESULTS Overall, 695 of 15,668 patients undergoing lumbar spine surgery had unplanned 30-day hospital readmissions (4.4%). When separated by procedure type, readmissions were lowest after discectomy, 3.3%, and highest after deformity surgery, 9.0% (P < 0.001). The top causes for readmission were wound-related (38.6%), pain-related (22.4%), thromboembolic (9.4%), and systemic infections (8.0%). Predictors of readmission included advanced patient age more than 80 years (P = 0.03), African American race (P = 0.03), recent weight loss (P = 0.04), chronic obstructive pulmonary disorder (P < 0.01), history of cancer (P = 0.04), creatinine more than 1.2 (P < 0.01), elevated ASA class (P = 0.01), operative time more than 4 hours (P = 0.01), and prolonged hospital length of stay more than 4 days (P < 0.01). CONCLUSION Thirty-day unplanned readmission rates increased with procedure invasiveness. Both medical and surgical reasons contributed to readmission, many unavoidable. Surgeons should explore optimization measures for those at risk of early, unplanned readmission. LEVEL OF EVIDENCE 3.
Interferon-γ-mediated Inhibition of Serum Response Factor-dependent Smooth Muscle-specific Gene Expression

IFNγ exerts multiple biological effects on effector cells by regulating many downstream genes, including smooth muscle-specific genes. However, the molecular mechanisms underlying IFNγ-induced inhibition of smooth muscle-specific gene expression remain unclear. In this study, we have shown that serum response factor (SRF), a common transcriptional factor important in cell proliferation, migration, and differentiation, is targeted by IFNγ in a STAT1-dependent manner. We show that the molecular mechanism by which IFNγ regulates SRF is via activation of the 2-5A-RNase L system, which triggers SRF mRNA decay and reduced SRF expression. As a result, decreased SRF expression reduces expression of SRF target genes such as smooth muscle α-actin and smooth muscle myosin heavy chain. Additionally, IFNγ reduced p300 and acetylated histone-3 binding in both smooth muscle α-actin and SRF promoters, epigenetically decreasing smooth muscle α-actin and SRF transcriptional activation. Our data reveal that SRF is a novel IFNγ-regulated gene and further elucidate the molecular pathway between IFNγ, IFNγ-regulated genes, and SRF and its target genes.
Acer rubrum (red maple) growth is negatively affected by soil from forest stands dominated by its invasive congener ( Acer platanoides , Norway maple)

Invasive species continue to alter the plant communities of the eastern United States. To better understand the mechanisms and characteristics associated with invasive success, we studied competition between two Acer species. In a greenhouse, we tested (1) the effect of forest soil type (beneath an invasive and native stand) on seedling growth of the invasive Acer platanoides (Norway maple) and native A. rubrum (red maple), and the (2) effects of full (above- and below-ground) and partial inter-specific competition on species growth. We found A. rubrum growth was negatively affected by soil from the invaded stand, as it had lower above-ground (32%) and below-ground (26%) biomass, and number of leaves (20%) than in the native soil. The root:shoot resource allocations of A. platanoides depended on soil type, as it had 14% greater root:shoot mass allocation in the native soil; this ability to change root:shoot allocation may be contributing to the ecological success of the species. Widely published as having a large ecological amplitude, A. rubrum may be a useful species for ecological restoration where A. platanoides has been present, but the impacts of A. platanoides on soil functioning and subsequent plant interactions must be addressed before protocols for native reintroductions are improved and implemented.
Increased Sensitivity of Human Colon Cancer Cells to DNA Cross-Linking Agents after GRP78 Up-Regulation

We have shown earlier that pre-treatment of V79 Chinese hamster cells with 6-aminonicotinamide (6-AN) or 2-deoxyglucose (2-dG) results in over-expression of the Mr 78,000 glucose-regulated stress protein (GRP78) and the subsequent development of resistance to inhibitors of topoisomerase II. These phenomena also occur in V79-derived cell lines that are deficient in poly(ADP-ribose) (p(ADPR)) metabolism. In contrast, over-expression of GRP78 under the conditions outlined above is found to be associated with hypersensitivity to several clinically-relevant DNA cross-linking agents, namely, 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU), cisplatin, and melphalan. We have also previously shown that pre-treatment with 6-AN, an inhibitor of p(ADPR) metabolism, causes an increase in the life span in BCNU-treated mice bearing L1210 tumors. These observations prompted us to examine whether 6-AN pre-treatment can result in the over-expression of GRP78 in human colon cancer cell lines and, if so, whether this increase is associated with sensitization to DNA cross-linking agents outlined above. Following treatment of three colon cancer cell lines, HCT116, SW480, and VACO-8, for 48 h with 0.1 mM 6-AN, cytosolic GRP78 levels were elevated approximately 4.2 times, 8 times, and 2.5 times for each cell line respectively, as measured by Western immunoblotting. To determine sensitivity after GRP78 up-regulation, the cells were washed and grown for 412 h in growth medium devoid of 6-AN, before being treated with DNA cross-linking agents. The 412 h time period allowed p(ADPR) metabolism to return to normal while GRP78 levels remained elevated, thus allowing us to associate GRP78 over-expression with sensitivity to those agents. After treating cells for 1 h with BCNU, cisplatin, or melphalan, cell sensitivity was determined by clonogenic survival assay or a fluorescence-based cytotoxicity assay. Based on changes in IC50 values, 6-AN caused an increase in sensitivity for HCT116, SW480, and VACO-8 cells of 1.5, 2.3, and 1.0 times, respectively, for BCNU, 4.8, 3.8, and 2.6 for cisplatin, and 6.4, 3.7, and 2.2 times for melphalan. Thus, our results show that over-expression of GRP78 in human tumor cell lines is associated with increased sensitivity to clinically useful chemotherapy agents. This sensitization occurred in three different tumor cell lines, each bearing a separate genetic defect associated with altered sensitivity.
DEVELOPMENTAL STUDIES OF THE DIPTERAN SALIVARY GLAND II. DNase Activity in Chironomus thummi

The deoxyribonuclease (DNase) activity of the dipteran (Chironomus thummi) salivary gland, measured both enzymatically and immunochemically, increases about 7-fold with the onset of metamorphosis. The increase in DNase activity occurs at a time when the activities of other enzymes and the total protein content are decreasing. The increased DNase activity is followed by glandular destruction. It is suggested that the alterations of this activity may be regulated by the activities of specific chromosomal sites, and that the enzyme may, at least in part, account for the glandular destruction observed at the time of increased enzyme activity.
Antibodies to selected disease agents in translocated wild turkeys in California.

Wild turkeys (Meleagris gallopavo) trapped within California (n = 715) or imported into California from other states (n = 381) from 1986 to 1996 were tested for exposure to certain disease agents. Prevalence of antibody to Mycoplasma gallisepticum, Mycoplasma meleagridis, Salmonella pullorum, Salmonella typhimurium, Newcastle disease virus, and avian influenza virus was low (0–4%) for wild turkeys trapped within California. With the exception of antibody prevalence to M. meleagridis of 33%, the same was true for wild turkeys imported into California from other states. Antibody prevalence to Mycoplasma synoviae was 8–10% for both groups.
The effects of bankruptcy filings on the competitors' earnings

Abstract In this paper, we investigate whether a bankruptcy filing explains the earnings of the bankrupt firm's competitors. We examine contagion and competitive effects on competitors' earnings for a sample of 165 bankruptcies filed between 1991 and 1996. Our findings show that the competitors experience an increase in return on equity (ROE) in concentrated industries than in less concentrated industries, suggesting a competitive effect. In addition, the competitive effect is observed in industries with high leverage and multiple bankruptcy filings. Our data fail to provide support for the contagion effect of bankruptcy on competitors' earnings.
The trade-off between production and transportation costs in determining optimal plant size

An important element of manufacturing strategy is to decide on the shipping radius and the size of a geographically focused plant. This decision involves a trade-off between exploiting economies of scale in production by building a large plant and decreasing transportation costs by building a small plant. The paper presents a model for analysing this trade-off. It is shown that scale economies in transportation facilitate the exploitation of production economies of scale. For an optimal sized plant, the ratio of transportation to production costs does not depend on the absolute cost levels in production and transportation, but only the economies of scale present in production and in transportation.
A learning algorithm for analog, fully recurrent neural networks

A learning algorithm for recurrent neural networks is derived. This algorithm allows a network to learn specified trajectories in state space in response to various input sequences. The network dynamics are described by a system of coupled differential equations that specify the continuous change of the unit activities and weights over time. The algorithm is nonlocal, in that a change in the connection weight between two units may depend on the values for some of the weights between different units. However, the operation of a learned network (fixed weights) is local. If the network units are specified to behave like electronic amplifiers, then an analog implementation of the learned network is straightforward. An example demonstrates the use of the algorithm in a completely connected network of four units. The network creates a limit cycle attractor in order to perform the specified task. >
Pulmonary Edema After Resection of a Fourth Ventricle Tumor: Possible Evidence for a Medulla-Mediated Mechanism

A well-recognized fact is that some patients may have development of pulmonary edema in association with disorders of the central nervous system. The origin of this phenomenon, known as neurogenic pulmonary edema, is unclear but may result, in part, from select pulmonary venoconstriction modulated by autonomic outflow from the medulla oblongata. We describe a 21-year-old man who had development of pulmonary edema in association with surgical resection of a brain tumor that was close to the medulla. Other than the possibility of medullary dysfunction, which could have occurred after surgical manipulation, no other risk factor for pulmonary edema was identified. Of note, the patient's blood pressure remained normal throughout the perioperative period, and no fluid overload or primary cardiac dysfunction was evident. This case supports the theory that the medulla is an important anatomic site of origin for neurogenic pulmonary edema and that alterations in medullary function can induce pulmonary edema in humans, independent of systemic hypertension.
HIV-1 induces renal epithelial dedifferentiation in a transgenic model of HIV-associated nephropathy

HIV-1 induces renal epithelial dedifferentiation in a transgenic model of HIV-associated nephropathy. Background Human immunodeficiency virus-associated nephropathy (HIVAN) is the most common cause of renal failure in HIV-1–seropositive patients. Recent studies using an HIV-1 transgenic mouse model have demonstrated that expression of HIV-1 in the kidney is required for the development of HIVAN. What has remained unclear, however, is the renal cell type responsible for pathogenesis and the essential pathological process. Methods To address these issues, we used a transgenic murine model of HIVAN. We identified the cell types in kidney in which HIV transgene expression occurs using in situ hybridization. We evaluated evidence of proliferation by immunocytochemical analysis using an antibody to Ki-67 and cell type-specific markers, including WT-1, synaptopodin, Na + ,K + -ATPase, adducin, and desmin. TUNEL assay was used to evaluate apoptosis. Results We found that glomerular and tubular epithelial cells express the HIV-1 transgene early in the disease process when renal architecture is well preserved. Transgene expression is lost, however, in tubular epithelial cells when they lose their differentiated cuboidal phenotype. In glomerular epithelial cells, dedifferentiation occurs with reduced expression of WT-1 and synaptopodin, in association with activation of desmin expression. Tubular microcysts also form with mislocalization of Na + ,K + -ATPase expression to the lateral and apical cellular membranes. Conclusions These studies support the hypothesis that the glomerular and renal epithelial cells are the primary targets of HIV-1 pathogenesis in the kidney. The essential pathologic process is dysregulation of the epithelial cell cycle with increased proliferation, apoptosis, cellular dedifferentiation, and altered cellular polarity.
Speculations on the growth strategy of prosthecate bacteria.

Appendaged bacteria with stalks that are extensions of the cell wall have had to solve the problems of growing the stalk as a tube of constant diameter and of partitioning their chromosomes into th...
The purification of Aeromonas aminopeptidase by affinity chromatography.

Abstract A competitive inhibitor for Aeromonas aminopeptidase has been prepared from the bromomethyl ketone derived from t -butyloxycarbonyl- l -leucine and successfully coupled to aminomethyl cellulose to form an adsorbent for affinity chromatography. The blocked form of the inhibitor was coupled to aminomethyl cellulose and then deblocked in aqueous trifluoroacetic acid to yield an insolubilized analog of an NH 2 -terminal l -leucyl residue. This material was effective in binding the aminopeptidase and separating it from a contaminating endopeptidase, which has a similar isoelectric point and size. Separation of the aminopeptidase and endopeptidase was shown to be due to the specificity of the affinity adsorbent for the aminopeptidase, inasmuch as separation of the enzymes did not occur on a typical anion exchange column or on a hydrophobic column lacking a free amino group.
A Study of Sea Surface Wind Vector Estimation From Near-Nadiral Cross-Track-Scanned Backscatter Data

The possibility of recovering sea surface wind vectors from near-nadiral cross-track Ku- or Ka-band backscatter measurements using a measuring geometry similar to that of the Airborne Precipitation Radar 2 is discussed. The cross-track scanning geometry includes diversity in both elevation and azimuth angles, allowing the possibility of both wind speed and direction retrieval to within a 180 ° direction ambiguity. A simulation study of wind vector retrieval accuracy is performed based on the use of the “cutoff-invariant two-scale model” of sea surface backscatter returns. The results show that a maximum likelihood retrieval approach utilizing data from the cross-track scan can provide reasonable wind vector retrieval accuracy.
"SHRIMP geochronology for the 1450 Ma Lakhna dyke swarm: Its implication for the presence of Eoarchaean crust in the Bastar Craton and 1450-517 Ma depositional age for Purana basin (Khariar), Eastern Indian Peninsula": Comment

Abstract As critical comments to the recent paper by Ratre et al. (2010, Journal of Asian Earth Sciences 39, 565–577) we cite U–Pb SHRIMP and CHIME ages of magmatic and detrital zircon and monazite from the Chhattisgarh and the Khariar basins in the Bastar craton to argue that these basins closed ca. 1000 Ma. We further argue that geochronologic data, geological evidence, and geological logic strongly indicate that sedimentation in the Khariar basin did not continue up to or beyond 517 Ma, as stated by Ratre et al. (op. cit).
Non-invasive lung function tests in rats with progressive papain-induced emphysema.

Non-invasive plethysmographic methods for measurement of thoracic gas volume (TGV), airway resistance (Raw) and phase difference (PD) between flow rate at the nose and mean alveolar pressure were adapted for use in anesthetized rats. Thirty-six male Sprague-Dawley rats (200-250 g), were treated in groups of six by a single transoral, intratracheal instillation of 2 mg . kg-1 or 4 mg . kg-1 of papain in saline, or left untreated as controls. Measurements of TGV, Raw, and PD were made before treatment and at 4-day intervals after treatment for 8 or 16 days. TGV increased 65 percent by the fourth day and showed no change beyond the eighth day. Raw (0.4 +/- 0.04 cm H20 . ml-1 . sec) was not different from that of the controls. PD did not change significantly from the pretreatment value (4.7 +/0 0.41 degrees). The TGV, Raw, and PD responses were similar in the 2 mg . kg-1 and 4 mg . kg-1 papain treated rats. The TGV results suggest that the destructive effects of papain on the lungs are complete by the eighth day. The Raw results indicate that the airways are unaffected. The PD data are consistent with theoretical modeling studies for uneven distribution of compliances but neglible inequality of peripheral resistances.
Between prolixity and reductionism : psychoanalytic theory and Occam's razor

To achieve a coherent theory of mental functioning, psychoanalysis cannot continue to explicate its observations through the “complementary“ use of models based on differing premises. Moreover, the current profusion of plausible theories is unmanageably prolix; it is true, however, that theory must account for the complexity of constant shifts of developmental levels in terms of currently used adaptive devices. The simplest possible clinical theory will add to existing theories of motivation and development only the concepts needed to explicate reasons for these shifts in modes of functioning. Motivations are preprogrammed in the brain, so that theories of motivation must be congruent with neurophysiological knowledge. But the current status of a person's organismic motivations can only be inferred on the basis of the affective reactions they generate.The acquisition of symbolic capacities changes the infant from an organism automatically striving to fulfill a preprogrammed ground plan into a creature of ...
Complementary Chimeric Isoforms Reveal Dscam1 Binding Specificity In Vivo

Dscam1 potentially encodes 19,008 ectodomains of a cell recognition molecule of the immunoglobulin (Ig) superfamily through alternative splicing. Each ectodomain, comprising a unique combination of three variable (Ig) domains, exhibits isoform-specific homophilic binding in vitro. Although we have proposed that the ability of Dscam1 isoforms to distinguish between one another is crucial for neural circuit assembly, via a process called self-avoidance, whether recognition specificity is essential in vivo has not been addressed. Here we tackle this issue by assessing the function of Dscam1 isoforms with altered binding specificities. We generated pairs of chimeric isoforms that bind to each other (heterophilic) but not to themselves (homophilic). These isoforms failed to support self-avoidance or did so poorly. By contrast, coexpression of complementary isoforms within the same neuron restored self-avoidance. These data establish that recognition between Dscam1 isoforms on neurites of the same cell provides the molecular basis for self-avoidance.
Synthesis of Aurivillius Ceramics by the Polymerized Complex Method

Aurivillius phases of the type Bi2Sr2Nb2TiO12 and Bi1.6Pb0.4Sr2Nb2Ti1-xAlxO12 (0.0 ≤ × ≤ 0.8) were synthesized by the polymerized complex method involving an organometallic precursor. The effect of raising the pH of the solution was investigated through the addition of ammonium hydroxide. Infrared spectroscopy was taken at various points in the reaction to generate a mechanism. The IR data showed the formation of an ester as well as an amide with the addition of ammonium hydroxide. Pure Bi2Sr2Nb2TiO12 was formed after heat treatment for 5 hours at 900°C for the unaltered solution and 5 hours at 700°C when the solution pH was raised to 9.00. A solubility limit of aluminum was determined for Bi1.6Pb0.4Sr2Nb2Ti1-xAlxO12 when x ≥ 0.4. Conductivity measurements at 1123 K of Bi1.6Pb0.4Sr2Ti1-xAlxO12 range from 4.76 × 10-3 S•cm-1 at x = 0.8 to 1.74×10-4 S•cm-1 at x = 0.1.
Increased tubulin messenger RNA in the goldfish retina during optic nerve regeneration.

Axotomy induces profound morphological changes in the neuronal cell body 2,a,1°. Neurons whose axons lie within the central nervous system of higher vertebrates (intrinsic neurons) show little or no functional regenerative capability 4,8. However, many mammalian neurons whose axons lie outside the CNS, e.g., sensory and motor neuronsS, 15 and some intrinsic CNS neurons of lower vertebrates, such as teleosts and amphibia, can regenerate functional axons and re-establish normal synaptic fieldsT,9,11. This recuperative response of the perikaryon to axotomy provides a model for the study of regeneration as well as synaptogenesis and other events thought to underlie neuronal growth, recognition and plasticity. Regeneration of functional retinotectal fibers following optic nerve crush in goldfish is associated with a number of quantifiable biochemical changes in the retina, including increased nucleoside uptake and phosphorylation 1. There is also an enhanced labeling of cytoplasmic poly(A)-containing RNA 1 and of the microtubule protein tubulin 6. The enhanced radioisotopic labeling of goldfish retinal tubulin following optic nerve crush could be attributed either to its increased synthesis or decreased degradation. Since the former explanation could reflect regulation at the transcriptional or translational level and axotomy had resulted in enhanced labeling of poly(A)containing RNA, we investigated whether retinal poly(A)-RNA obtained following optic nerve crush was enriched in specific messenger RNAs, particularly that for tubulin. Translation of retinal poly(A)-containing RNA in a heterologous, cell-free protein synthesizing system, followed by SDS gel electrophoresis of the products, provided the necessary tools to detect the proposed changes in RNA populations. Cytoplasmic poly(A)-containing RNA preparations were isolated from both normal and from post-crush retinas, then incubated in a wheat germ protein synthesizing system. The protein labeling patterns from 4, 10 and 15 day post-crush incubations and their controls are shown in Fig. 1. A distinct increase in radioautographic density in the tubulin region of the gel was apparent in proteins translated
New upper bounds and reduced dynamical modeling for Rayleigh–Bénard convection in a fluid saturated porous layer

New rigorous upper bounds on the enhancement of heat transport in a fundamental model of porous medium convection are presented. The computational results are applied to the development of finite dimensional dynamical systems models of porous medium convection. The number of degrees of freedom in the full dynamics and the dimension of potentially faithful reduced descriptions are discussed.
Archaeal CCA-adding Enzymes CENTRAL ROLE OF A HIGHLY CONSERVED β-TURN MOTIF IN RNA POLYMERIZATION WITHOUT TRANSLOCATION

The CCA-adding enzyme (tRNA nucleotidyltransferase) builds and repairs the 3′ end of tRNA. A single active site adds both CTP and ATP, but the enzyme has no nucleic acid template, and tRNA does not translocate or rotate during C75 and A76 addition. We modeled the structure of the class I archaeal Sulfolobus shibatae CCA-adding enzyme on eukaryotic poly(A) polymerase and mutated residues in the vicinity of the active site. We found mutations that specifically affected C74, C75, or A76 addition, as well as mutations that progressively impaired addition of CCA. Many of these mutations clustered in an evolutionarily versatile β-turn located between strands 3 and 4 of the nucleotidyltransferase domain. Our mutational analysis confirms and extends recent crystallographic studies of the highly homologous Archaeoglobus fulgidus enzyme. We suggest that the unusual phenotypes of the β-turn mutants reflect the consecutive conformations assumed by the β-turn as it presents the discriminator base N73, then C74, and finally C75 to the active site without translocation or rotation of the tRNA acceptor stem. We also suggest that β-turn mutants can affect nucleotide selection because the growing 3′ end of tRNA must be properly positioned to serve as part of the ribonucleoprotein template that selects the incoming nucleotide.
Light‐activated plant defence

Sunlight provides the energy required for all biochemical, physiological and developmental processes necessary for plant growth, reproduction and survival. The role of light in photosynthesis and photomorphogenesis has been appreciated for some time; however, the role of light in plant defence is a comparatively recent realization. Between 75-100 photosensitizers or phototoxins, molecules that become toxic in the presence of light, have been extracted from higher plant tissues. These biologically-active compounds have diverse biosynthetic origins and belong to at least 15 different phytochemical classes (i.e. acetophenones, acetylenes, benzophenanthrenes, β-carbolines, coumarins, extended quinones, furanochromones, furanocoumarins, furanoquinolines, isoquinolines, lignans, pterocarpans, quinolines, sesquiterpenes and thiophenes). Of more than 100 angiosperm families assayed, phototoxins and/or phototoxic activity have been reported in c. 40 families representing 32 orders and 8 subclasses of the Magnoliophyta. Most of these allelochemicals are acute toxins with little organism-specificity. As such, they are effective biocides capable of killing a wide-range of potentially harmful organisms including: viruses, pathogenic bacteria and fungi, nematodes and herbivorous insects, as well as competing plant species. This review focuses on the phytochemistry, taxonomic occurrence and toxicological consequences of phototoxic metabolites in flowering plants. The available information suggests that phototoxic phytochemicals: (i) are broad-spectrum allelochemicals capable of protecting plants against a variety of detrimental organisms in nature, (ii) represent a successful defensive strategy in both primitive and advanced plant taxa, and (iii) may be an effective defence under a variety of photoenvironmental conditions. CONTENTS Summary 401 I. Introduction 401 II. Chemistry/biochemistry of plant photosensitizers 402 III. Botanical distribution of photosensitizers 403 IV. Toxicology 405 V. Biological activity/defensive role of photosensitizers 408 VI. Concluding remarks 413 References 415.
Specific food sensitiveness

To sum up, then, although there are more disappointments than miracles in the search for and the curing of severe manifestations of food sensitiveness, the miracles are so gratifying when they come that, each time, the clinician will resolve to spend more time looking for them. The field is still much neglected; more diets much be fitted and fewer handed out ready made. A good history will often show that the diet is probably not the cause for the patient’s discomfort. Patients much not be left too long on narrow elimination diets; such diets are for testing and not for treatment. Some cases of diarrhea and pseudo-ulcer are due to the milk that is taken by way of treatment, and not infrequently certain foods irritate or greatly depress the brain. Somnolence after meals can be due to a particular food, and canker sores in the mouth can be produced by food. Efforts to use an elimination diet are often instructive in showing the physician that he is dealing with an unreasonable, overly fussy, querulous, or psychopathic person. Food sensitiveness is not necessarily allergic or due to protein. Perhaps partly for this reason, skin tests are of little help in finding the foods that cause indigestion.
Solution of the Michaelis-Menten equation using the decompositionmethod

We present a low-order recursive solution to the Michaelis-Menten equation using the decomposition method. This solution is algebraic in nature and provides a simpler alternative to numerical approaches such as differential equation evaluation and root-solving techniques that are currently used to compute substrate concentration in the Michaelis-Menten equation. A detailed characterization of the errors in substrate concentrations computed from decomposition, Runge-Kutta, and bisection methods over a wide range of $s_{0} $:$K_{m}$ values was made by comparing them with highly accurate solutions obtained using the Lambert $W$ function. Our results indicated that solutions obtained from the decomposition method were usually more accurate than those from the corresponding classical Runge-Kutta methods. Moreover, these solutions required significantly fewer computations than the root-solving method. Specifically, when the stepsize was 0.1% of the total time interval, the computed substrate concentrations using the decomposition method were characterized by accuracies on the order of 10$^-8$ or better. The algebraic nature of the decomposition solution and its relatively high accuracy make this approach an attractive candidate for computing substrate concentration in the Michaelis-Menten equation.
Evolutionary Evaluation: implications for evaluators, researchers, practitioners, funders and the evidence-based program mandate.

Abstract Evolutionary theory, developmental systems theory, and evolutionary epistemology provide deep theoretical foundations for understanding programs, their development over time, and the role of evaluation. This paper relates core concepts from these powerful bodies of theory to program evaluation. Evolutionary Evaluation is operationalized in terms of program and evaluation evolutionary phases, which are in turn aligned with multiple types of validity. The model of Evolutionary Evaluation incorporates Chen's conceptualization of bottom-up versus top-down program development. The resulting framework has important implications for many program management and evaluation issues. The paper illustrates how an Evolutionary Evaluation perspective can illuminate important controversies in evaluation using the example of the appropriate role of randomized controlled trials that encourages a rethinking of “evidence-based programs”. From an Evolutionary Evaluation perspective, prevailing interpretations of rigor and mandates for evidence-based programs pose significant challenges to program evolution. This perspective also illuminates the consequences of misalignment between program and evaluation phases; the importance of supporting both researcher-derived and practitioner-derived programs; and the need for variation and evolutionary phase diversity within portfolios of programs.
Some factors involved in the skin flap delay phenomenon

Abstract The use of skin flaps for reconstruction following extensive ablative surgery in the head and neck area has played a major role on the improvement of the results being attained. Using the pig as an experimental animal various factors of flap orientation, skin incisions and flap undermining were investigated. Results confirmed the ineffectiveness of incision alone as a delay maneurver and suggested that anatomical orientation of cutaneous skin flaps was not of crucial significance. The complete mechanism of the positive effects of delay remains undefined.
Development of a scale measuring genetic variation related to expressive control

It has been theorized that a substantial genetic component underlies the Self-Monitoring Scale. The identity of this component, however, is not yet known. In order to identify and better understand it, a more precise measure of the component is required. The present research attempted to (a) identify an axis of the self-monitoring two-factor space with maximum genetic variance; and (b) bootstrap a scale more highly correlated with this genetic maximum than is the Self-Monitoring Scale using twins. Evaluation of the new scale against criteria of validity indicates that scale construction was reasonably successful. The new measure had a cross-validated monozygotic twin intraclass correlation of .76 and a dizygotic twin intraclass correlation of .16. This work yields a new research tool and suggests a new approach to personality assessment. Correlates of the new measure as well as theoretical and methodological issues relevant to the measurement of a latent genetic entity are discussed.
KEKB and PEP-II B factories

Two asymmetric B-Factories KEKB at KEK and PEP-II at SLAC are under construction, designed to study CP violation in the b-quark sector with a center of mass energy of 10.58 GeV. These two new accelerators are high luminosity two-ring two-energy e{sup +}e{sup {minus}} colliders with one interaction point. There are many challenging accelerator physics and engineering issues associated with the high beam currents and high luminosities of these rings. The chosen solutions to these issues and the general parameters of the two rings are described in detail side-by-side. KEKB and PEP-II are well into the installation phase and are both scheduled to be completed in 1998. The particle physics programs are scheduled to start in 1999.
Age effects on forebrain commissure section and interocular transfer.

Four monkeys with their forebrain commissures transected during the newborn period and four others of comparable age but with their commissures sectioned in later life sustained further midsagittal section of the optic chiasma. They were then tested on the interocular transfer of a series of visual discrimination tasks involving brightness, color and pattern cues. No definite differences in the characteristics of transfer were found between the groups, and none of the animals exhibited clear-cut evidence for positive transfer on the tasks as a whole.
Electronic current models of vibrational circular dichroism

Abstract Three classes of VCD intensity models are presented to explore the nature of VCD spectra whose primary electric and magnetic-dipole contributions are due to the flow of electronic charge density associated with a single driving oscillator. The models, chosen as prototypic geometrical chiral structures, consists of a three-bond fragment, a helical structure and a closed-ring structure.
Embryonic modifications of lacertilian intracranial arteries.

Intracranial arteries were studied in Crotaphytus adults and in a series of Lacerta embryos. At an early embryonic period, the mesencephalic artery develops posterior to the bifurcation of the cerebral carotid; as the pontine flexure forms at a subsequent stage, the carotid bifurcation becomes relocated further posteriorly, with the result that the definitive mesencephalic artery becomes an outgrowth of the anterior encephalic artery. Additional significant modifications include the progressive fusion of the two posterior encephalic arteries and the extensive branching of the middle cerebral artery along the lateral regions of the hemisphere. During late stages of development, the circulation to the olfactory region is gradually assumed by extracranial arteries, although remnants of intracranial olfactory arteries may occasionally be retained.
Opposing Polymerase-Deadenylase Activities Regulate Cytoplasmic Polyadenylation

Summary Cytoplasmic polyadenylation is one mechanism that regulates translation in early animal development. In Xenopus oocytes, polyadenylation of dormant mRNAs, including cyclin B1, is controlled by the cis -acting cytoplasmic polyadenylation element (CPE) and hexanucleotide AAUAAA through associations with CPEB and CPSF, respectively. Previously, we demonstrated that the scaffold protein symplekin contacts CPEB and CPSF and helps them interact with Gld2, a poly(A) polymerase. Here, we report the mechanism by which poly(A) tail length is regulated. Cyclin B1 pre-mRNA acquires a long poly(A) tail in the nucleus that is subsequently shortened in the cytoplasm. The shortening is controlled by CPEB and PARN, a poly(A)-specific ribonuclease. Gld2 and PARN both reside in the CPEB-containing complex. However, because PARN is more active than Gld2, the poly(A) tail is short. When oocytes mature, CPEB phosphorylation causes PARN to be expelled from the ribonucleoprotein complex, which allows Gld2 to elongate poly(A) by default.
The occurrence of muscle spindles in extraocular muscles of various vertebrates.

Extraocular muscles from representative species of vertebrate groups ranging from amphibians to the higher mammals were examined in serial histological sections for the presence of muscle spindles. These observations and data from the literature indicate that extraocular muscles of the pig, calf, sheep and other even-toed ungulates are richly supplied with well-defined spindles having a generous complement of intrafusal fibers distinguishable as nuclear bag and chain fibers. Spindles in human eye muscles are also numerous. In macaque and chimpanzee muscles a few poorly developed spindles were present in some, but not all, muscles. No encapsulated receptors were found in 20 other mammalian and submammalian species examined in this study. When present, spindles tended to be located in the zone of small muscle fibers found along the orbital surface of the muscle. Rectus and oblique muscles in all species had such a zone, so that its existence did not determine whether spindles would occur.
Generation and characterization of a complete null estrogen receptor α mouse using Cre/LoxP technology

Conventional estrogen receptor α knockout (neo-ERαKO, neo-ERα−/−) mice contain a truncated and chimeric ERα fusion protein that retains 35% estrogen-dependent transactivation activity, and therefore the in vivo ERα function is difficult to study thoroughly. Furthermore, these neo-ERα−/− mice cannot be used for tissue and temporal specific ERα deletion. Therefore, there is a clear need to establish a floxed ERα mouse line that can knockout ERα specifically and completely in each selected cell type. Here we generated floxed ERα mice using a self-excising ACN (tACE-Cre/Neo) cassette. Mating the floxed ERα mice with ACTB-Cre mice produces a deletion of the floxed allele disrupting the reading frame of the ERα transcript so that no ERα protein is detected in the ACTB-Cre/ERα−/− mice. Expression of ERα target genes, such as G-6-PD and lactoferrin, is diminished by over 90% in the ACTB-Cre/ERα−/− uterus, but not in the neo-ERα−/− uterus. Furthermore, we also validated that ACTB-Cre/ERα−/− females have a hypoplastic internal genital tract, polycystic ovaries with hemorrhagic follicles, infertility, and higher body weight. Together, our data clearly demonstrate that the newly established floxed ERα mouse is a reliable mouse model for future studies of ERα roles in vivo in the selective estrogen target tissues. The complete knockout of ERα in the ACTB-Cre/ERα−/− mice will also provide an improved mouse model to study the role of ERα in vivo.
An Investigation of the Operational Acceptability of Algorithm-generated Sector Combinations

In this paper, algorithm-generated airspace sector combinations are analyzed to determine if they are operationally acceptable. Discussions with practitioners identified three desirable characteristics for operational sector combinations. The first is that at each time during a weekly cycle, approximately the same number of sectors are operational. The second is that sector combinations be familiar, and the third is that sector combinations do not change frequently. Methods for visualizing and quantifying these characteristics are proposed. The methods are used to analyze historical sector combinations from the national airspace system and sector combinations generated by a sector-combining algorithm. The results were analyzed by researchers and practitioners. This analysis indicates that changes to the sector-combining algorithm may be required to ensure combinations that are acceptable for current operations. However, the identified characteristics may be less important in a mid-term timeframe (�2018), which is when a sector combining algorithm is being targeted for deployment. I. Introduction In current operations, supervisors in Air Route Traffic Control Centers (ARTCCs or centers) dynamically combine sectors when they are under-utilized (operating below their capacity). This is done primarily so that there are not more controller teams monitoring airspace than are necessary. There are many factors that impact supervisor decisions about when to combine and split sectors, such as air traffic levels, staff availability and capabilities, equipment availability, current and predicted weather, airport configurations, and air traffic demand management initiatives. Currently, these decisions are made based on supervisor experience and judgement. Some previous research has focused on predicting sector combinations and splits based on past supervisor decisions. 1 In Ref. 2, an algorithm to systematically suggest combinations of under-utilized airspace sectors has been proposed. Results suggest that this algorithm may utilize air traffic control resources more efficiently than they are currently utilized. However, feedback from practitioners regarding the sector combination algorithm in Ref. 2 suggests that the proposed sector combinations may not be operationally acceptable due to controller situational awareness and staff planning factors that are not explicitly considered in the algorithm. 3 In this research, the algorithm-suggested sector combinations are compared to historical sector combinations to determine if the algorithm produces operationally acceptable sector combinations. Three desirable characteristics of operational sector combinations specified by practitioners in Ref. 3 are investigated. Quantitative comparisons are designed to study each characteristic in the operational and algorithm-generated sector combinations. Further practitioner feedback on the results of these comparisons is reported.
Self-consistent, unbiased exclusion methods of emittance analysis

We present a self-consistent method for analyzing measured emittance data that yields unbiased estimates for the rms emittance as well as its associated uncertainty. The self-consistent, unbiased elliptical exclusion analysis, SCUBEEx, uses an exclusion ellipse to determine the bias from the data outside the ellipse, before calculating the emittance from the bias-subtracted data within the ellipse. Variations of the ellipse size, shape, and orientation allow for objectively estimating the bias and the rms emittance.