cssi/SciSciGPT-SciSciNet huggingface dataset:
Genetic construction of truncated and chimeric metalloproteins derived from the alpha subunit of acetyl-CoA synthase from Clostridium thermoaceticum.

In this study, a genetics-based method is used to truncate acetyl-coenzyme A synthase from Clostridium thermoaceticum (ACS), an alpha2beta2 tetrameric 310 kda bifunctional enzyme. ACS catalyzes the reversible reduction of CO2 to CO and the synthesis of acetyl-CoA from CO (or CO2 in the presence of low-potential reductants), CoA, and a methyl group bound to a corrinoid-iron sulfur protein (CoFeSP). ACS contains 7 metal-sulfur clusters of 4 different types called A, B, C, and D. The B, C, and D clusters are located in the 72 kda beta subunit while the A-cluster, a Ni-X-Fe4S4 cluster that serves as the active site for acetyl-CoA synthase activity, is located in the 82 kda alpha subunit. The extent to which the essential properties of the cluster, including catalytic, redox, spectroscopic, and substrate-binding properties, were retained as ACS was progressively truncated was determined. Acetyl-CoA synthase catalytic activity remained when the entire alpha subunit was removed, as long as CO, rather than CO2 and a low-potential reductant, was used as a substrate. Truncating an {approx} 30 kda region from the N-terminus of the alpha subunit yielded a 49 kda protein that lacked catalytic activity but exhibited A-cluster-like spectroscopic, redox, and CO binding properties. Further truncation afforded a 23 kda protein that lacked recognizable A-cluster properties except for UV-vis spectra typical of [Fe4S4]2+ clusters. Two chimeric proteins were constructed by fusing the gene encoding a ferredoxin from Chromatium vinosum to genes encoding the 49 kda and 82 kda fragments of the alpha subunit. The chimeric proteins exhibited EPR signals that were not the simple sum of the signals from the separate proteins, suggesting magnetic interactions between clusters. This study highlights the potential for using genetics to simplify the study of complex multi-centered metalloenzymes and to generate new complex metalloenzymes with interesting properties.
The structure of the CARD8 caspase-recruitment domain suggests its association with the FIIND domain and procaspases through adjacent surfaces.

CARD8 plays crucial roles in regulating apoptotic and inflammatory signaling pathways through the association of its caspase-recruitment domain (CARD) with those of procaspase-9 and procaspase-1. The CARD8 CARD has also been predicted to form an intramolecular complex with its FIIND domain. Here, the first crystal structure of the CARD8 CARD is reported; it adopts a six-helix bundle fold with a unique conformation of the α6 helix that is described here for the first time. The surface of the CARD8 CARD displays a prominent acidic patch at its α2, α3 and α5 helices that may interact with the procaspase-9 CARD, whereas an adjacent charged surface at its α3 and α4 helices may associate with the CARD8 FIIND domain without interfering with the CARD–CARD interaction. This suggests that the function of CARD8 may be regulated by both intramolecular and intermolecular interactions involving electrostatic attractions.
January issue of performance improvement an excellent read

The editor welcomes letters from all readers wishing to comment on articles in this issue of Performance Improvement (PI). Early responses have the best chance of being published. Please be concise and include your title and organizational affiliation. PI reserves the right to select, solicit, and edit letters. Send letters to: PI Editor, 1300 I. Street, NW, Suite 1250, Washington, DC 20005: fax: 202-408-7972: or email: pershin@indiana.edu.
Social support and conformity: The role of independent assessment of reality

Abstract This study investigated the role of one factor in the reduction of conformity produced by a partner who agrees with the subject in the face of group pressure: the independent assessment of social and physical reality provided by the partner. Two social support conditions were created, differing only in the subject's perception of the partner's adequacy as a valid referent for making judgments. A unanimous group was also included to provide a conformity base line. Results indicated that the Valid Social Support condition produced a significantly greater decrease in conformity than did the Invalid Social Support condition, though both conditions reduced conformity relative to the unanimous group. Results support the hypothesis that independent assessment of reality provided by a partner is an important factor underlying the efficacy of social support in reducing conformity.
A survey of methodology for the global minimization of concave functions subject to convex constraints

Abstract Methodology is described for the global solution to problems of the form minimize f ( x ) subject to x ∈ G , u i ⩾ x i ⩾ l i where f ( x ) is a concave function of the vector x in R n space and G is a convex polytope. This paper investigates recent work accomplished to solve this problem. Basically, solution algorithms can be categorized into three distinct areas: (1) branch-and-bound methods, (2) cutting plane methods, and (3) build-up of polyhedra methods. Computational experience with these methods is also examined. Particular attention is paid to the possibility for extension of these algorithms to problems of large scale, specifically to those evidencing separable objective functions which are subject to linear sets of constraints.
A CONTINUOUSLY RECORDING INSTRUMENT TO MEASURE AIR-BORNE ION CONCENTRATION.

Abstract A vacuum tube electrometer was developed and used in conjunction with portable, shortened concentric cylinder ion collectors which is capable of monitoring ion concentrations in air. The electrometer can operate high impedance recorders which produce a continuous recording of ion levels in ambient air with a time constant of approximately 30 seconds, with proportionally faster response for higher levels of concentration.
Oxidation of 1-butanol and a mixture of n-heptane/1-butanol in a motored engine

Abstract The oxidation of neat 1-butanol and a mixture of n -heptane and 1-butanol was studied in a modified CFR engine at an equivalence ratio of 0.25 and an intake temperature of 120 °C. The engine compression ratio was gradually increased from the lowest point to the point where significant high temperature heat release was observed. Heat release analyses showed that no noticeable low temperature heat release behavior was observed from the oxidation of neat 1-butanol while the n -heptane/1-butanol mixture exhibited pronounced cool flame behavior. Species concentration profiles were obtained via GC–MS and GC-FID/TCD. Quantitative analyses of the reaction products from the oxidation of neat 1-butanol indicate that 1-butanol is consumed mainly through H-atom abstraction. Among the H-atom abstraction reactions, it is observed that the H-atom abstraction from the α-carbon of 1-butanol is particularly favored. The investigation on the oxidation of the mixture of n -heptane/1-butanol showed that the oxidation of 1-butanol is facilitated at low temperatures through the radical pool generated from the oxidation of n -heptane.
Restricted hyporheic exchange in an alluvial river system: implications for theory and management

AbstractLarge-scale patterns of hyporheic exchange are predictable within some river systems, but our understanding of the factors driving hyporheic processes and the magnitude of hyporheic exchange needed to influence biophysical patterns at larger scales remains limited. We investigated the patterns, magnitude, and potential effects on biota of reach-scale hyporheic exchange in an alluvial river of the Pacific Northwest. The river was topographically similar to and in the same geographic region as other systems where large-scale hyporheic exchange and associated biological responses have been observed. We hypothesized that predictable reach-scale patterns of hyporheic exchange would occur in alluvial valley segments of the river and that hyporheic upwelling would be associated with reach-scale patterns of physical and biological characteristics. We used in-channel piezometers and synoptic stream flow measurements to quantify hyporheic exchange. We measured temperature, dissolved O2, pH, specific conduct...
Application of rate equations to ELDOR and saturation recovery experiments on 14N:15N spin-label pairs

Rate equations describing the time dependence of population differences of the five allowed transitions in an 14N15N spin-label pair problem are set up. Included in the formulation are the three Heisenberg exchange rate constants and different nitrogen nuclear spin-lattice relaxation rates, electron spin-lattice relaxation rates, and populations for the 14N and 15N moieties. Using matrix algebra, stationary and time-dependent solutions are obtained in a unified theoretical framework. The calculations apply to stationary and pulse electron-electron double resonance and to saturation-recovery ESR. Particular emphasis is placed on short pulse initial excitation, where the transverse relaxation processes are sufficiently slow that only the population difference of the irradiated transition departs significantly from Boltzmann equilibrium during the excitation.
Oxidatively induced DNA-protein cross-linking between single-stranded binding protein and oligodeoxynucleotides containing 8-oxo-7,8-dihydro-2'-deoxyguanosine

The formation of covalent cross-links between amino acid side chains and DNA bases in DNA-protein complexes is a significant pathway in oxidative damage to the genome, yet much remains to be learned about their chemical structures and mechanisms of formation. In the present study, DNA-protein cross-links (DPCs) were formed between synthetic oligodeoxynucleotides containing an 8-oxo-7,8-dihydro-2'deoxyguanosine (OG) or an 8-oxo-7,8-dihydro-2'-deoxyadenosine (OA) nucleotide and Escherichia coli singled-stranded binding protein (SSB) under oxidative conditions. Studies with various sequences indicated that DNA homopolymers and those lacking 8-oxopurines were less reactive toward DPC formation. DPCs were formed in the presence of HOCl, peroxynitrite, and the one-electron oxidants Na(2)IrCl(6), Na(2)IrBr(6), and Na(3)Fe(CN)(6). Protein-protein cross-linking was also observed, particularly for oxidants of high reduction potential such as Na(2)IrCl(6). The adducted oligodeoxynucleotides were sensitive to hot piperidine treatment leading to strand scission at the site of cross-linking. In addition, the covalent cross-links were somewhat heat and acid labile, which may be related to the difficulties encountered in obtaining complete characterization of trypsin digests of the DPCs. However, model reactions involving the single amino acids lysine, arginine, and tyrosine, residues known to be involved in base contacts in the DNA:SSB complex, could be studied, and the adduct formed between N(alpha)-acetyllysine methyl ester and an 18-mer containing OG was tentatively characterized by electrospray ionization mass spectrometry as analogues of spiroiminodihydantoin and guanidinohydantoin. A mechanism involving nucleophilic attack of an amino acid side chain (e.g. the epsilon-amino group of lysine) at C5 of a 2-electron oxidized form of OG is proposed.
A transposon-related palindromic repetitive sequence from C. elegans

Abstract A family of transposon-like sequences in the C. elegans genome is described. This family, termed the Tc6 family, consists mostly of conserved, 1.6 kb elements. Four Tc6 elements or partial elements have been cloned and the DNA sequences of three were determined. One appears to be a complete element of 1603 nucleotides, consisting of a palindrome of 765 nucleotides, with a central, non-palindromic region of 73 nucleotides. Another has an identical structure except for an internal deletion. A third is a partial element terminating at a probable internal restriction site used for cloning. A fourth clone contained portions of the Tc6 sequence juxtaposed to non-Tc6 sequences. All C. elegans strains examined contain 20-30 Tc6 elements. The ends of Tc6 elements are conserved and have sequence similarity to the ends of C. elegans transposons Tc1 and Tc3. The ends of Tc6 elements also have sequence similarity to the heptamer portion of the immunoglobulin and T-cell receptor recombination signal sequence, raising the possibility of wide phylogenetic conservation of the recombination mechanism. Tc6 elements also share sequence motifs with plant-pathogenic viroid RNA's, possibly indicative of a Tc6 RNA replicative phase.
Mapping swirls and pseudo-spines of compact 4-manifolds

Abstract A compact subset X of the interior of a compact manifold M is a pseudo-spine of M if M − X is homeomorphic to (∂M) × [0, ∞). It is proved that a 4-manifold obtained by attaching k essential 2-handles to a B3 × S1 has a pseudo-spine which is obtained by attaching k B2's to an S1 by maps of the form z → zn. This result recovers the fact that the Mazur 4-manifold has a disk pseudo-spine (which may then be shrunk to an arc). To prove this result, the mapping swirl (a “swirled” mapping cylinder) of a map to a circle is introduced, and a fundamental property of mapping swirls is established: homotopic maps to a circle have homeomorphic mapping swirls. Several conjectures concerning the existence of pseudo-spines in compact 4-manifolds are stated and discussed, including the following two related conjectures: every compact contractible 4-manifold has an arc pseudo-spine, and every compact contractible 4-manifold has a handlebody decomposition with no 3- or 4-handles. It is proved that an important class of compact contractible 4-manifolds described by Poenaru satisfies the latter conjecture.
Choreoathetoid movements in cocaine dependence.

Abstract Background: To evaluate the severity of choreoathetoid movements in cocaine dependent (CD) subjects and age-matched normal control subjects. Methods: Choreoathetoid movements were evaluated using the Abnormal Involuntary Movement Scale (AIMS) in samples of 71 CD, 56 normal control, and 9 amphetamine-dependent male subjects. Results: The CD subjects had a significantly increased nonfacial (limbs plus body) AIMS subscore. When the nonfacial AIMS scores of the two groups were compared in relation to age, a significant age by diagnosis interaction was observed, indicating that the differences between groups were most marked in the younger age groups. The facial AIMS scores were also increased but only in the youngest CD cohort (under 32 years of age). The comparison group of 9 younger amphetamine-dependent subjects also showed increased AIMS scores. Conclusions: Increases in choreoathetoid movements in younger cocaine and amphetamine-dependent subjects may be related to their psychostimulant use. The absence of differences in choreoathetoid movements between the older CD subjects and normal control subjects may represent an age-related self-selection effect.
Aqueous Accessibility to the Transmembrane Regions of Subunit c of the Escherichia coli F1F0 ATP Synthase

Rotary catalysis in F1F0 ATP synthase is powered by proton translocation through the membrane-embedded F0 sector. Proton binding and release occur in the middle of the membrane at Asp-61 on transmembrane helix (TMH) 2 of subunit c. Previously the reactivity of Cys substituted into TMH2 revealed extensive aqueous access at the cytoplasmic side as probed with Ag+ and other thiolate-directed reagents. The analysis of aqueous accessibility of membrane-embedded regions in subunit c was extended here to TMH1 and the periplasmic side of TMH2. The Ag+ sensitivity of Cys substitutions was more limited on the periplasmic versus cytoplasmic side of TMH2. In TMH1, Ag+ sensitivity was restricted to a pocket of four residues lying directly behind Asp-61. Aqueous accessibility was also probed using Cd2+, a membrane-impermeant soft metal ion with properties similar to Ag+. Cd2+ inhibition was restricted to the I28C substitution in TMH1 and residues surrounding Asp-61 in TMH2. The overall pattern of inhibition, by all of the reagents tested, indicates highest accessibility on the cytoplasmic side of TMH2 and in a pocket of residues around Asp-61, including proximal residues in TMH1. Additionally subunit a was shown to mediate access to this region by the membrane-impermeant probe 2-(trimethylammonium)ethyl methanethiosulfonate. Based upon these results and other information, a pocket of aqueous accessible residues, bordered by the peripheral surface of TMH4 of subunit a, is proposed to extend from the cytoplasmic side of cTMH2 to Asp-61 in the center of the membrane.
Preparing Ed.D. Students to Conduct Group Dissertations

In this article we present an overview of a recently launched cohort-based Ed.D. program that prepares participants to conduct group dissertations. The program, a hybrid model of online learning activities and monthly face-to-face class sessions, is delivered through a partnership between a university’s college of education and the administrative office of a statewide system of community and technical colleges. Discussion begins with a review of the pedagogical rationale that informed program design and instructional practices, followed by a presentation of key program elements tracing the development of the cohort through an innovative, collaborative dissertation process still in progress.
Metabolic Testing in the Pediatric Epilepsy Unit

Unexplained mental retardation is noted in up to 3% of the general population, and upwards of 30% of these patients manifest epilepsy. There is no standardized approach to metabolic testing in these patients. In a first step toward a standardized approach for our center, we performed a retrospective evaluation of testing of our patients in the past. Records of 429 children admitted to our pediatric epilepsy-monitoring center in 2005 were reviewed. We noted whether they had developmental delay, their type of epilepsy, and the extent of metabolic testing. Ninety percent of our patients had developmental delay, and 20% received some form of metabolic testing. Abnormal results suggesting mitochondrial dysfunction were found in 28% of our patients without a previous underlying diagnosis. Metabolic abnormalities were found in 75% of those with multifocal interictal discharges. Secondary carnitine deficiency was identified in 22%; these patients were taking valproic acid. Primary or secondary metabolic abnormalities likely represent a prominent finding in these patients. Differential diagnoses involving mitochondrial dysfunction should receive serious consideration. Findings such as carnitine deficiency can be identified and treated. A systematic approach for such testing is needed. A prospective evaluation at our institution is planned.
Design of a reversible bidirectional barrel shifter

Reversible logic has promising applications in the field of quantum computing, optical computing, low power computing, and other emerging computing technologies. A barrel shifter that can shift and rotate multiple bits in a single cycle is an important component of many computing units. This paper presents the reversible design of bidirectional arithmetic and logical barrel shifter. The proposed design consists of the reversible Fredkin and Feynman gates. The Fredkin gate used in the design of reversible bidirectional arithmetic and logical barrel shifter can implement the 2∶1 MUX with minimum quantum cost, minimum number of ancilla bits and minimum number of garbage outputs while the Feynman gate is used to avoid the fanout as fanout is not allowed in the reversible logic. The design is evaluated in terms of number of garbage outputs, quantum cost and number of ancilla bits.
A review and analysis of backpropagation neural networks for classification of remotely-sensed multi-spectral imagery

Abstract A literature survey and analysis of the use of neural networks for the classification of remotely-sensed multi-spectral imagery is presented. As part of a brief mathematical review, the backpropagation algorithm, which is the most common method of training multi-layer networks, is discussed with an emphasis on its application to pattern recognition. The analysis is divided into five aspects of neural network classification: (1) input data preprocessing, structure, and encoding, (2) output encoding and extraction of classes, (3) network architecture, (4) training algorithms, and (5) comparisons to conventional classifiers. The advantages of the neural network method over traditional classifiers are its nonparametric nature, arbitrary decision boundary capabilities, easy adaptation to different types of data and input structures, fuzzy output values that can enhance classification, and good generalization for use with multiple images. The disadvantages of the method are slow training time, inconsis...
Locating and estimating the extent of Delmarva fox squirrel habitat using an airborne LiDAR profiler

Abstract Two thousand five hundred thirty-nine kilometers of airborne laser profiling and videography data were acquired over the state of Delaware during the summer of 2000. The laser ranging measurements and video from approximately one-half of that data set (1304 km) were analyzed to identify and locate forested sites that might potentially support populations of Delmarva fox squirrel (DFS, Sciurus niger cinereus ). The DFS is an endangered species previously endemic to tall, dense, mature forests with open understories on the Eastern Shore of the Chesapeake Bay. The airborne LiDAR employed in this study can measure forest canopy height and canopy closure, but cannot measure or infer understory canopy conditions. This airborne LiDAR profiler, then, must be viewed as a tool that identifies and locates potential, not actual, habitat. Fifty-three potentially suitable DFS sites were identified in the 1304 km of flight transect data. Each of the 53 sites met the following criteria according to the LiDAR and video record: (1) at least 120 m of contiguous forest; (2) an average canopy height >20 m; (3) an average canopy closure of > 80%; and (4) no roofs, impervious surface (e.g., asphalt, concrete), and/or open water anywhere along the 120 m length of the laser segment. Thirty-two of the 53 sites were visited on the ground and measurements taken for a DFS habitat suitability model. Seventy-eight percent of the sites (25 of 32) were judged by the model to be suited to supporting a DFS population. All of the LiDAR flight data, 2539 km, were analyzed to estimate county and statewide forest area in different height/canopy closure classes. Approximately 3.3% of Delaware (17,137 ha) supports forest over 20 m tall with crown closures exceeding 80%; the corresponding county percentages are Newcastle County—6.1% (6823 ha), Kent County—2.2% (3431 ha), and Sussex County—2.7% (6883 ha). Estimates of average within-patch crossing distance and average between-patch distances are reported, by county, and for the state. Study results indicate that: 1) systematic airborne LiDAR data can be used to screen extensive areas to locate potential DFS habitat; 2) 78% of sites meeting certain minimum length, height, and canopy closure criteria will support DFS populations, according to a habitat suitability model; 3) airborne LiDAR can be used to calculate county and state acreage estimates of potential habitat, and 4) the linear transect data can be used to calculate patch statistics. The authors suggest that the systematic county and state flight lines can be revisited at intervals to monitor changes to the areal extent of potential habitat over time.
Patterns of Irrigated Agricultural Land Conversion in a Western U.S. Watershed: Implications for Landscape-Level Water Management and Land-Use Planning

In irrigated agricultural landscapes, land-use conversion may have landscape-level social, hydrological, and ecological effects. We used geographic information systems (GIS) and interviews to analyze development effects on irrigation in the Henry's Fork Watershed, Idaho. Farmers developed irrigation there in the 19th century, and incidental recharge from canal seepage and flood irrigation raised groundwater levels and expanded wetlands. Cohesive culture in agricultural communities sustained irrigation systems until amenity-driven demographic shifts beginning in the 1970s led to development approved by local governments with land-use planning but no water-management authority. Although only 5% of irrigated land has been converted, development has fragmented irrigated landscapes and made canal-system operation more difficult, potentially reducing groundwater levels, wetland extent, and return flows critical to downstream irrigators and fish and wildlife. We discuss future scenarios, highlighting the need fo...
Intracardiac echocardiography in the detection of pacemaker lead endocarditis

Abstract At times, infection of pacemaker leads can be difficult to confirm even with transesophageal echocardiography. We describe a patient with pacemaker lead infection where the transesophageal echocardiogram was nondiagnostic, and intracardiac echocardiography made the diagnosis by demonstrating the vegetation on the pacemaker lead. This illustrates a potential role for intracardiac echocardiography in infective endocarditis when transesophageal echocardiography is nondiagnostic. (J Am Soc Echocardiogr 2002;15:1027-8.)
Arachidonic acid metabolism during early development of ovine embryos: a possible relationship to shedding of the zona pellucida.

Two experiments were conducted to determine if early ovine embryos produce prostaglandins and if prostaglandins may have a role in the shedding of the zona pellucida, i.e., embryo hatching. For Experiment 1, embryos were collected on day (d) 4, 8, 10, 12 or 14 of pregnancy and incubated with 1 microCi of [14C] arachidonic acid (AA) for 24 h. Based upon high-performance liquid chromatography, embryos from all days converted AA to a number of compounds; the amounts produced differed with day. Primarily, embryos produced an unidentified polar compound, 6-keto-PGF1 alpha, PGF2 alpha, PGE2, 13,14-dihydro-15-keto-PGF2 alpha and PGB2. For Experiment 2, embryos collected on d 7 of pregnancy were incubated for a maximum of 6 d in 500 microL of medium containing either ethanol (control; 20 microL), indomethacin (INDO; 10(-4) M), PGE2 (2 ng) or INDO (10(-4) M) + PGE2 (2 ng). Embryos were evaluated daily for hatching from the zona pellucida. The hatching rates (percentage) for control, INDO, PGE2 and INDO + PGE2 were 46.4, 34.5, 60.0, and 30.0, respectively. There was a main effect (P < .09) of treatment, and the hatching rate for embryos treated with PGE2 alone was greater (P < .05) than that for embryos in any group with INDO. The results indicate that early ovine embryos can convert AA to various compounds in vitro, and prostaglandins may have a role in the hatching of sheep embryos from the zona pellucida.
Analysis of bulk fabrics and microstructure variations using tesselations of autocorrelation functions

"Lazy ACF Tiles", a macro written for the public domain program "NIH Image", is presented. The macro permits the user to calculate local and bulk autocorrelation functions (ACFs) of halftone images such as photomicrographs of geological thin sections. Single ACFs, rows, or tessellations of ACFs can be calculated. ACF analysis is especially useful for the detection of subtle microstructures (weak anisotropies), and for the evaluation of large data sets. Segmentation of images (grain boundary contouring) is not necessary. Images do not have to be square. The macro is in the public domain and a powerpoint manual is provided with it. As an example, the application of "Lazy ACF Tiles" to an experimentally deformed sample of quartzite is demonstrated. The ACF analysis reveals a periodic flattening intensity along the compressional axis of the sample, which cannot be detected with the unaided eye.
Setting military reenlistment bonuses

Abstract : The United States military frequently has difficulty retaining enlisted personnel beyond their initial enlistment. A bonus program within each service, called a Selective Reenlistment Bonus (SRB) program, seeks to enhance reenlistments and thus reduce personnel shortages in critical military occupational specialties (MOSs). The amount of bonus is set by assigning "SRB multipliers" to each MOS. We develop a nonlinear integer program to select multipliers which minimize a function of deviations from desired reenlistment targets. A Lagrangian relaxation of a linearized version of the integer program is used to obtain lower bounds and feasible solutions. The best feasible solution, discovered in a coordinate search of the Lagrangian function, is heuristically improved by apportioning unexpended funds. For large problems, a heuristic variable reduction is employed to speed model solution. U.S. Army data and requirements for FY87 yield a 0-1 integer program with 12,992 binary variables and 273 constraints, which is solved within 0.00002% of optimality on an IBM 3033AP in less than 1.7 seconds. More general models with up to 463,000 binary variables are solved, on average, to within 0.009% of optimality in less than 1.8 minutes. The U.S. Marine Corps has used a simpler version of this model since 1986.
Estradiol and progesterone influence the response of ventromedial hypothalamic neurons to tactile stimuli associated with female reproduction

Stimulation of the vagina and cervix, provided by the male during copulation or manually with a probe, causes many behavioral and endocrine changes associated with female reproduction in rats. Previously, we found that vaginal-cervical stimulation (VCS), by mating or manual probing, increases the expression of Fos-immunoreactivity (Fos-IR) in discrete populations of neurons in the preoptic area, mediobasal hypothalamus and midbrain, suggesting that these neurons respond to VCS. The purpose of the present study was to determine if hormonal priming would increase the number of Fos-IR cells following VCS. Contrary to our hypothesis, in Experiment 1 priming animals with a behaviorally effective dose of 17 beta-estradiol benzoate followed 48 h later by progesterone caused a trend towards a decrease in the number of VCS-induced Fos-IR cells in the ventromedial hypothalamus. In Experiment 2, which was done to confirm this decrease in VCS-induced Fos-IR neurons by hormones, this effect was found to be statistically significant. Furthermore, this hormone-induced decrease in VCS-responsive cells was localized to the ventromedial nucleus of the hypothalamus, an area rich in estrogen and progestin receptors. No effects of hormone treatment on VCS-induced Fos-IR were observed in any other brain regions analyzed. These findings suggest that steroid hormones may elicit some of their effects on female reproductive behavior and physiology by altering the responsiveness of ventromedial nucleus neurons to vaginal-cervical stimulation.
Effects of thinning and deer browsing on breeding birds in New England oak woodlands

Over a 3-year period we compared the effects of forest thinning and white-tailed deer (Odocoileus virginianus) browsing intensity on breeding birds in central Massachusetts oak (Quercus spp.) forests across 12 stands with dominant trees having a diameter at breast height greater than 27.9 cm. Unthinned stands with few deer had moderately dense woody understories and moderate ground cover; unthinned stands with many deer had sparse woody understories and little ground cover. Thinned stands with few deer had dense, tall woody understories and moderate ground cover; thinned stands with many deer had sparse woody understories and lush ground cover. Understory changes associated with high deer densities were apparently offset by effects of thinning so that thinned stands supported more breeding bird species. We recorded 65 species of birds; 28 occurred in all treatment classes. Thinned stands contained significantly (P < 0.05) more bird species than did unthinned stands. Of species that occurred more than once, nine occurred only in thinned stands, one occurred only in uncut stands, and another only in stands with 13–23 deer km−2. Occurrences of six species differed significantly (P < 0.05) by deer browsing intensity or thinning. Numbers of omnivores and ground gleaners (both species and individuals) were greater in thinned stands. Numbers of canopy gleaners were greater in stands with 1–3 deer km−2.
Persistence of Human Papillomavirus Infection in HIV-Infected and -Uninfected Adolescent Girls: Risk Factors and Differences, by Phylogenetic Type

Background. High rates of persistence of human papillomavirus (HPV) infection have been reported for adult women with human immunodeficiency virus (HIV) infection. Although most women are first infected with HPV during adolescence, persistence of specific HPV types has not been carefully examined among HIV-infected adolescents. The objective of this study was to examine the rates of and risk factors for persistence of HPV types among HIV-infected and -uninfected adolescent girls. Methods. This is a prospective cohort study of female adolescents, aged 13-18 years, participating in the Reaching for Excellence in Adolescent Care and Health project, a national study of HIV-infected and -uninfected adolescents. The main outcome measured was type-specific loss of initial HPV DNA detected. Loss of HPV DNA was defined for the following categories of HPV DNA types: low risk, which included types 6, 11, 42, 44, 54, 40, 13, 32, 62, 72, 2, 57, and 55; and high risk, which included types 16-like (16, 31, 33, 35, 52, 58, and 67), 18-like (18, 39, 45, 59, 68, 70, 26, 69, and 51), and 56-like (56, 53, and 66). Results. Prevalent or incident HPV infection was detected in 334 girls. When type-specific loss of HPV was examined, HIV-uninfected girls had a shorter mean time to loss of initial infection than did HIV-infected girls (403 days vs. 689 days, respectively; P<.0001). By means of multivariate analysis, CD4 immunosuppression and the presence of multiple HPV-type subgroups were found to be associated with persistence of HPV. Conclusion. Since persistence of high-risk HPV types has been strongly linked with the development of invasive cancer, the prolonged persistence of HPV observed among HIV-infected adolescents who are relatively healthy underscores the importance of prevention of HPV infection in this group.
Effects of Progesterone on Developing Chick Embryos

Experiments were conducted to examine the effects of progesterone on the developing chick embryo with particular attention to the reproductive system. Differing levels of progesterone (0, .5, 1.0, or 2.0 mg) were dissolved in propylene glycol and injected at 4 days of incubation into the yolk sac of eggs from Barred Plymouth Rock females mated to New Hampshire males. Progesterone caused significant reductions in both weight and length and shank weight and length in 18-day-old embryos. Aside from reductions in embryonic growth, progesterone did not cause gross alterations in embryonic development. Progesterone modified neither normal morphology nor differentiation of male or female gonads and associated ductal systems.
Prolonged wet period in the southwestern United States through the Younger Dryas

The Younger Dryas was one of the more dramatic climatic transitions ever recorded. How these types of climatic shifts are expressed in continental interiors is of primary scientific interest and of vital societal concern. Here we present a speleothem-based absolutely dated record (using uranium-series data) of climate change for the southwestern United States from growth chronology of multiple speleothems. The stalagmite growth represents the onset of wetter climate (12,500 yr B.P.) soon after the start of the Younger Dryas; the wetter climate persisted a millennium beyond the termination of the Younger Dryas. This wet cycle is likely related to a more southern positioning of the polar jet stream in response to cooler Northern Hemisphere climate. The end of the wet period coincides with the peak of the Holocene summer insolation maximum ca. 10,500 yr B.P. The Allerod (prior to the Younger Dryas), which corresponds to Clovis occupation in the southwestern United States, was drier in comparison and seems in line with a climatic contribution to megafauna extinction.
Family Involvement and Post-IPO Investment Policy:

Drawing from agency theory and socioemotional wealth considerations, we evaluate the extent post-IPO investment policy choices and their economic consequences differ for family firms relative to nonfamily firms. Our results suggest that family firms underinvest in post-IPO liquidity, total investment spending, and R&D expenditures, relative to similar non-family firms. On the other hand, family firms overinvest in capital spending and underinvest in acquisition spending relative to nonfamily firms with dispersed but not concentrated ownership structures. Furthermore, while increases in R&D spending decrease shareholder value in family firms, the reverse is the case with acquisition spending.
Heterodimers of the SnoN and Ski oncoproteins form preferentially over homodimers and are more potent transforming agents

sno is a member of the ski oncogene family and shares ski 's ability to transform avian fibroblasts and induce muscle differentiation. Ski and SnoN are transcription factors that form both homodimers and heterodimers. They recognize a specific DNA binding site (GTCTAGAC) through which they repress transcription. Efficient homodimerization of Ski, mediated by a bipartite C-terminal domain consisting of five tandem repeats (TR) and a leucine zipper (LZ), correlates with efficient DNA binding and cellular transformation. The present study assesses the role of SnoN homodimerization and SnoN:Ski heterodimerization in the activities of these proteins. Unlike Ski, efficient homodimerization by SnoN is shown to require an upstream region of the protein in addition to the TR/LZ domain. Deletion of the TR/LZ from SnoN decreases its activity in transcriptional repression and cellular transformation. When co-expressed in vitro, c-Ski and SnoN preferentially form heterodimers. In vivo, they form heterodimers that bind the GTCTAGAC element. Tethered Ski:Sno hetero-dimers that lack TR/LZ domains are more active than either their monomeric counterparts, tethered Ski:Ski homodimers or full-length SnoN and c-Ski. This work demonstrates, for the first time, the differences between dimer formation by Ski and SnoN and underscores the importance of dimerization in their activity.
Ultrastructure of the bladder in classic exstrophy: correlation with development of continence.

ABSTRACTPurpose: Successful initial surgical management of bladder exstrophy does not always lead to continence. We evaluated the ultrastructure of the exstrophic bladder using electron microscopy (EM) at various stages of reconstruction to determine whether morphology could correlate with the potential for continence.Materials and Methods: Bladder specimens obtained from 32 patients undergoing various stages of exstrophy reconstruction were evaluated by EM. Specimens were obtained at primary newborn closure (group 1–10), reclosure following failure (group 2–2), bladder neck reconstruction (group 3–9) and augmentation cystoplasty (group 4–11). Evaluation was performed by a single anatomist with experience with EM. Biopsies were separated into those with good, intermediate or poor ultrastructural parameters and then correlated clinically.Results: In group 1, 4 children had good and 2 had intermediate parameters. All showed increased bladder volumes at followup. Four patients had poor parameters and poor bl...
Analysis of a Non-linear Partial Difference Equation, and Its Application to Cardiac Dynamics

A model of a strip of cardiac tissue consisting of a one-dimensional chain of cardiac units is derived in the form of a non-linear partial difference equation. Perturbation analysis is performed on this equation, and it is shown that regular perturbations are inadequate due to the appearance of secular terms. A singular perturbation procedure known as the method of multiple scales is shown to provide good agreement with numerical simulation except in the neighborhood of a singularity of the slow flow. The perturbation analysis is supplemented by a local numerical simulation near this singularity. The resulting analysis is shown to predict a "spatial bifurcation" phenomenon in which parts of the chain may be oscillating in period-2 motion while other parts may be oscillating in higher periodic motion or even chaotic motion.
Interior-point methods for optimization

This article describes the current state of the art of interior-point methods (IPMs) for convex, conic, and general nonlinear optimization. We discuss the theory, outline the algorithms, and comment on the applicability of this class of methods, which have revolutionized the field over the last twenty years.
Phoenix clones: recovery after long-term defoliation- induced dormancy

Many long-lived plants are known to prolong dormancy in response to abiotic stresses such as drought. We are unaware, however, of any reports of plants prolonging dormancy in response to biotic stresses such as herbivory. We monitored 140 putative Solidago missouriensis clones (hereafter ‘clones’) ≥ 13 years before, during and after intense defoliation by the specialist herbivore Trirhabda canadensis. Eight of the clones produced no above-ground growth in the season following defoliation. Though apparently killed, these clones reappeared 1–10 years after they disappeared, with six of them robustly recovering in a single season. We used 38 RAPD markers to test the hypotheses (denoted by H and numbered with subscripts) that territories were recovered by (H1) seedling establishment or (H2) rhizomes. We compared pre-defoliation and post-recovery genotypes in two clones using the same 38 markers. Our data document the existence of very large clones (60–350 m2 with c. 700–20 000 ramets), and support the hypothesis that recovery is from rhizomes. Within-clone diversity is low, and the pre-defoliation and post-recovery genotypes match. We consider mechanisms that could enable plants entering dormancy with depleted resources to robustly recover, and the implications of dormancy for avoiding biotic stress such as that induced by T. canadensis.
A Salmonella protein causes macrophage cell death by inducing autophagy

Salmonella enterica, the causative agent of food poisoning and typhoid fever, induces programmed cell death in macrophages, a process found to be dependent on a type III protein secretion system, and SipB, a protein with membrane fusion activity that is delivered into host cells by this system. When expressed in cultured cells, SipB caused the formation of and localized to unusual multimembrane structures. These structures resembled autophagosomes and contained both mitochondrial and endoplasmic reticulum markers. A mutant form of SipB devoid of membrane fusion activity localized to mitochondria, but did not induce the formation of membrane structures. Upon Salmonella infection of macrophages, SipB was found in mitochondria, which appeared swollen and devoid of christae. Salmonella-infected macrophages exhibited marked accumulation of autophagic vesicles. We propose that Salmonella, through the action of SipB, kills macrophages by disrupting mitochondria, thereby inducing autophagy and cell death.
Fabrication of Grain-Oriented PbBi2Nb2O9

This paper describes a process for the fabrication of grain-oriented PbBi2Nb2O9 ceramics. A molten salt technique was used to synthesize crystallites of PbBi2Nb2O9 with a high degree of shape anisotropy. Tape casting and subsequent uniaxial hot-pressing resulted in ceramics with grain orientation of >90% with densities >96% theoretical.
Advances toward new antidepressants beyond SSRIs: 1-aryloxy-3-piperidinylpropan-2-ols with dual 5-HT1A receptor antagonism/SSRI activities. Part 1.

A series of 1-aryloxy-3-piperidinylpropan-2-ols possessing potent dual 5-HT1A receptor antagonism and serotonin reuptake inhibition was discovered. 1-(1H-Indol-4-yloxy)-3-(4-benzo[b]thiophen-2-ylpiperidinyl)propan-2-ols exhibited selective and high affinities at the 5-HT1A receptor and serotonin reuptake site in vitro. In vivo evaluation of this series of compounds demonstrated elevated extracellular serotonin levels from the basal and quick recovery of neuron firing that was presumably suppressed by the initial acute activation of 5-HT1A somatodendritic autoreceptors.
Linear focal elastosis: A degenerative or regenerative process of striae distensae?

may represent a degenerative or regenerative process of striae distensae. Why the elastic tissue accumulates preferentially in striae ofthebackis unclear. I believe Burket et al. were correct in identifying this as a distinct clinical pathologic entity, but their second term, elastotic striae, may be a more appropriate and descriptive appellation. Linear focal elastosis: A degenerative or regenerative process of striae distensae?
Modulation of Host Defenses with Interferon-γ in Pediatrics

One of the most consistent defects in the neonate's host defense system is in the ability of polymorphonuclear leukocytes (PMNL) to move in a unidirectional fashion towards a chemotactic stimulus. Such impaired chemotaxis can be an important contributor to life-threatening neonatal infection. In vitro studies suggest that preincubation of PMNL from neonates with recombinant human interferon-γ (rIFN-γ) can enhance chemotactic responses. No other recombinant human cytokine except granulocyte colony-stimulating factor improved chemotaxis of PMNL from neonates
A double-stage injection-locked oscillator for optically fed phased array antennas

In an optically fed phased array antenna system, the microwave carrier signal is transmitted via a modulated lightwave to each active T/R (transmit/receive) module, where it must be converted back to the microwave domain. Currently, efficient optical-to-microwave conversion is extremely difficult, as the detected microwave signal is weak and noisy. A novel circuit, containing a high-gain/low-noise microwave injection-locked oscillator, has been developed to improve the interface between the optical and microwave components. The circuit utilizes two FETs and a dielectric resonator, which serves as a frequency-dependent feedback element. The circuit, designed to operate at about 8 GHz, provides significant amplitude and phase noise suppression. In addition, the circuit realization is compatible with MMIC technology. >
Femtosecond Laser-Induced Micro-Structuring of Thin a-Si:H Films

In a-Si:H solar cells, light trapping has been sought as a method to enhance absorption and improve the efficiencies of these devices. Here we present results for surface texturing of 2μm thick a-Si:H films by 800 nm wavelength femtosecond laser. The texture led to a significant enhancement in optical absorption (80%) in visible through near IR (60%). The textured surface was examined by a scanning electron microscope (SEM) and atomic force microscope (AFM). The results indicated the formation of dense spikes with height of 65–75 nm. The samples were completely black after femtosecond laser treatment.
Predicting oxygen saturation levels in blood using autoregressive models: A threshold metric for evaluating predictive models

This paper presents preliminary results for using data driven models to describe the natural dynamics of the Pulse Oximetry Monitoring signals. Linear autoregressive discrete time models are used to predict future levels of oxygen saturation in patients' blood. While standard modeling methods are used in identifying dynamic systems models for these physiological signals, a performance objective based on a threshold is proposed to evaluate the predictive models. We discuss why standard evaluation metrics that have been commonly used in analyzing engineering systems may not be relevant for physiological ones even though standard modeling techniques may still give acceptable results. Using the proposed evaluation metric, we show that the combination of predictive models with frequent pulse oximetry measurements can be used as a warning of critical oxygen desaturation events that might have adverse effects on the health of patients.