cssi/SciSciGPT-SciSciNet huggingface dataset:
Ecology of fishes in a high-latitude, turbid river with implications for the impacts of hydrokinetic devices

Hydrokinetic devices generate electricity by capturing kinetic energy from flowing water as it moves across or through a rotor, without impounding or diverting the water source. The Tanana River in Alaska, a turbid glacial system, has been selected as a pilot location to evaluate the effects of such a device on fish communities that are highly valued by subsistence, sport, and commercial users. The basic ecology and habitat use of fishes in turbid glacial systems are poorly understood; therefore it is necessary to study the species composition of the fish community and the spatial and temporal patterns of mainstem river use by these fishes to evaluate impacts of a hydrokinetic device. In this document, we provide an overview of existing knowledge of fish ecology in the Tanana River and impacts of hydrokinetic devices on fishes in other river systems. Seventeen fish species are known to inhabit the Tanana River and several may utilize the deepest and fastest section of the channel, the probable deployment location for the hydrokinetic device, as a seasonal migration corridor. Previous studies in clearwater river systems indicate that mortality and injury rates from turbine passage are low. However, the results from these studies may not apply to the Tanana River because of its distinctive physical properties. To rectify this shortcoming, a conceptual framework for a comprehensive fish ecology study is recommended to determine the impacts of hydrokinetic devices on fishes in turbid, glacial rivers.
Genetic analysis of mutations to increased virulence in Magnaporthe grisea

An isolate of Magnaporthe grisea, 70-14, virulent on 10 cultivars of rice, but avirulent on rice cultivar Katy, was mutagenized with nitrosoguanidine. Four mutants of independent origin that showed an increase in virulence on Katy were recovered. The virulence on the other 10 rice cultivars was not affected. The lesion size caused by these mutants was intermediate between the parent avirulent isolate, 70-14 (infection type 1), and a virulent isolate, 70-6 (infection type 4). The numbers of lesions also decreased at least 10-fold when compared to numbers of lesions caused by a virulent wild-type isolate. A range of lesion types (0-4) was common in these mutant isolates, with both small and large lesions. In contrast, wild-type virulent isolates always gave large lesions [...]
Coumarin tags for analysis of peptides by MALDI-TOF MS and MS/MS. 2. Alexa Fluor 350 tag for increased peptide and protein Identification by LC-MALDI-TOF/TOF MS.

The goal of this study was the development of N-terminal tags to improve peptide identification using high-throughput MALDI-TOF/TOF MS. Part 1 of the study was focused on the influence of derivatization on the intensities of MALDI-TOF MS signals of peptides. In part 2, various derivatization approaches for the improvement of peptide fragmentation efficiency in MALDI-TOF/TOF MS are explored. We demonstrate that permanent cation tags, while significantly improving signal intensity in the MS mode, lead to severe suppression of MS/MS fragmentation, making these tags unsuitable for high-throughput MALDI-TOF/TOF MS analysis. In the present work, it was found that labeling with Alexa Fluor 350, a coumarin tag containing a sulfo group, along with guanidation of e-amino groups of Lys, could enhance unimolecular fragmentation of peptides with the formation of a high-intensity y-ion series, while the peptide intensities in the MS mode were not severely affected. LC-MALDI-TOF/TOF MS analysis of tryptic peptides from ...
Quo vadis? How should we train cardiologists at the turn of the century?

Background —Cardiovascular medicine is weathering challenges on multiple fronts, and the paradigm of cardiovascular fellowship training has changed as a result. Methods and Results —On the basis of a review of the literature and surveys of former trainees, we have evaluated our Cardiovascular Fellowship Program at the University of Iowa. We have identified principles fundamental to the training of fellows. We extend these principles to propose practical ideas for responding to the challenges we face in the rapidly changing landscape of medicine in a new millennium. Conclusions —We have proposed a few principles and numerous concrete, practical suggestions that will guide our Cardiovascular Fellowship in the future. These ideas may prove useful to other training programs.
Cholinesterase activities and sodium movement in the crayfish kidney.

Abstract 1. 1. Cholinesterase activities were studied in the crayfish kidney. The activity of this enzyme is 0.27 μM AChBr/mg N/min. Six hours after the injection of eserine, the activity is reduced to 0.11 μM AChBr/mg N/min. 2. 2. Cholinesterase is most concentrated in the bladder followed by the tubule, with some activity in the coelomoduct and labyrinth. 3. 3. There is a movement of Na22 from the crayfish kidney into the hemocoel as shown by the appearance of radioactivity in the tail region after the introduction of Na22 into the bladder. This movement can be inhibited with eserine. This is also demonstrated in isolated kidneys in van Harreveld's solution. 4. 4. It is suggested that cholinesterase, present in the bladder and tubule of the crayfish kidney, is functional in the sodium reabsorption mechanism.
Roles of microstructure in fatigue crack initiation

Abstract Fatigue failure in the high-cycle and ultrahigh-cycle regimes is often dominated by the crack initiation processes, which are strongly influenced by the salient features and defects in the microstructure. Competing fatigue mechanisms involving crack initiation at persistent slipbands, grain boundaries, pores, and non-metallic inclusions or particles, have been reported to occur at surface sites in the high-cycle fatigue regime (10 6 –10 7 cycles), but shift to interior sites in the ultrahigh-cycle fatigue regime (10 9 –10 10 cycles). The changes in fatigue mechanism and crack initiation site result in large variations in fatigue life. This overview article examines the roles of microstructural features such as grain size, texture, porosity, non-metallic inclusion in the fatigue crack initiation process and the manners by which these microstructural effects affect the shape of the stress–life curves.
Detection of Surface-Bound Organophosphate Compounds with Dual-Pulse Photofragmentation / Laser-Induced Fluorescence

We present a new method for remotely detecting organophosphate-containing chemicals on surfaces. The approach employs two laser pulses - the first to fragment the analyte; the second to measure a selected fragment using laser-induced fluorescence.
Randomized study of the safety and clinical utility of rotational vs. standard coronary angiography using a flat-panel detector.

The purpose of this study was to test the hypothesis that rotational angiography improves patient safety while maintaining diagnostic accuracy for patients undergoing coronary angiography. Despite advances in angiographic technique, patients remain at risk for complications of coronary angiography, including contrast-induced nephropathy and radiation exposure. Technology has been developed to perform coronary angiography with active rotation of the imaging system that may reduce the quantity of contrast and radiation to which the patient is exposed. Fifty patients undergoing diagnostic cardiac catheterization were randomized to either standard vs. rotational angiography of the coronary arteries using a prespecified protocol with a flat-panel single-plane imaging system. We measured the quantity of radiographic contrast utilized and radiation exposure. Using an intention-to-treat analysis, there was a 40% reduction (24 ± 5 vs. 40 ± 10 ml; P < 0.0001) in contrast utilization in the rotational group compared to the standard group. Neither radiation exposure (35 ± 14 vs. 30 ± 20 Gycm2; P = 0.35), fluoroscopic time (44 ± 33 vs. 44 ± 40 sec; P = 0.99), nor procedure time (249 ± 137 vs. 214 ± 79 sec; P = 0.26) differed, although significant intraoperator variability was noted for both standard and rotational angiography. The radiation exposure using this flat-panel system is significantly lower than prior reports that used an image intensifier system. Rotational coronary angiography has the potential to improve patient safety by markedly reducing radiographic contrast exposure while maintaining comparable diagnostic accuracy, radiation exposure, and procedure time compared to standard coronary angiography. © 2005 Wiley-Liss, Inc.
Sensing nectar's sweetness

In a brief comment on the sense of taste, Charles Darwin noted that “Real taste [in] the mouth, in my theory must be acquired by certain foods being habitual—[and] hence become hereditary” ( 1 ). This view, that taste perception and diet form a coordinated evolutionarily guided system, has received renewed support from recent behavioral, physiological, and molecular studies of comparative taste. On page 929 of this issue, Baldwin et al. ( 2 ) describe a striking example of this coordination in sweet nectar–eating hummingbirds—the repurposing of an amino acid taste receptor to respond to sugars and other sweeteners, permitting these birds to occupy a whole new avian niche.
Covalent interactions of 1,2,3-trichloropropane with hepatic macromolecules: Studies in the male F-344 rat

Preliminary investigations into the role of biotransformation in 1,2,3-trichloropropane (TCP)-induced tumor formation have been undertaken. Male F-344 rats were administered 30 mg/kg [14C]TCP (100 μCi/kg) ip and killed 4 hr later. The extent of covalent binding to hepatic protein, DNA, and RNA was 418, 244, and 432 pmol [14C]TCP equivalents/mg, respectively. An in vivo covalent binding time course showed no significant change in [14C]TCP equivalents bound to hepatic DNA (1–48 hr), while binding to protein was maximal by 4 hr and decreased significantly by 48 hr. The binding of TCP-associated radioactivity to hepatic protein and DNA was shown to be cumulative for two and three doses when given 24 hr apart. Pretreatment of animals with phenobarbital caused a decrease while pretreatment with SKF 525-A caused an increase in covalent binding of [14C]TCP equivalents to protein and DNA. Pretreatment of rats with β-naphthoflavone did not alter the covalent binding of [14C]TCP equivalents to protein or DNA. However, glutathione depletion with l-buthionine-(R,S)-sulfoximine increased binding to protein by 342% while it decreased binding to DNA by 56%. Intraperitoneal administration of TCP also depleted hepatic GSH by 41 and 61% 2 hr after doses of 30 and 100 mg/kg. The in vivo binding data suggest a dual role for GSH in the bioactivation of TCP. It may, in part, be that GSH is involved in the bioactivation and covalent binding of TCP to hepatic DNA. However, it also appears to detoxify a reactive intermediate(s) that binds to protein.
Inbred strain variation in contextual and cued fear conditioning behavior

A number of commonly used inbred strains were surveyed in a fear-conditioning paradigm conducted with an automated computer-controlled system. Control studies were used to verify the automated system. Response to shock was also monitored to determine if it was associated with contextual and/or cued conditioning behavior. After three pairings of tone with shock, fear conditioning was measured 24 h later in 129S1/SvImJ (129), A/J (A), BALB/cByJ (BALB), C3H/HeJ (C3H), C57BL/6J (B6), CBA/J (CBA), DBA/2J (D2), and FVB/NJ (FVB) male and female mice. There were both significant strain and sex differences in response. To determine the effects of vision on this behavior, C3H mice (with retinal degeneration) were compared with C3.BLiA-+Pde6b congenics (without retinal degeneration). Here, vision was found to play a minimal role in responsiveness in this paradigm. Because this fear-conditioning test is automated, it can be used for the rapid screening of a large number of mice, such as required for mutagenesis studies.
Density functional approaches to the dynamics of phase transitions

Density functional approaches have become well known in applications of equilibrium statistical mechanics to phase diagrams, interfacial structures, and free energies. This paper describes how these methods can be extended to the dynamics of phase transitions. Two aspects are emphasized: the calculation of free-energy barriers in nucleation and of growth velocities for crystallization from the melt. Significant deviations from classical nucleation theory and from diffusion-based theories of crystal growth are found. The continuum density functional approach is effective in describing the dynamics of collective-mode fluctuations, which dominate single-particle dynamics in these cases. The role of body-centred ordering at the interface between a face-centred crystal and the melt is described.
Effect of extended surface plasmons on surface enhanced Raman scattering

Abstract Surface enhanced Raman scattering of pyridine adsorbed to weakly roughened silver films is studied using a well-characterized extended surface plasmon excitation. We show that the additional increase in the Raman signal associated with the extended surface plasmon is fully accounted for by the enhancement in the average macroscopic field.
Maintaining distributed hypertext infostructures: welcome to MOMspider's Web

Abstract Most documents made available on the World-Wide Web can be considered part of an infostructure — an information resource database with a specifically designed structure. Infostructures often contain a wide variety of information sources, in the form of interlinked documents at distributed sites, which are maintained by a number of different document owners (usually, but not necessarily, the original document authors). Individual documents may also be shared by multiple infostructures. Since it is rarely static, the content of an infostructure is likely to change over time and may vary from the intended structure. Documents may be moved or deleted, referenced information may change, and hypertext links may be broken. As it grows, an infostructure becomes complex and difficult to maintain. Such maintenance currently relies upon the error logs of each server (often never relayed to the document owners), the complaints of users (often not seen by the actual document maintainers), and periodic manual traversals by each owner of all the webs for which they are responsible. Since thorough manual traversal of a web can be time-consuming and boring, maintenance is rarely or inconsistently performed and the infostructure eventually becomes corrupted. What is needed is an automated means for traversing a web of documents and checking for changes which may require the attention of the human maintainers (owners) of that web. The Multi-Owner Maintenance spider (MOMspider 1 ) has been developed to at least partially solve this maintenance problem. MOMspider can periodically traverse a list of webs (by owner, site, or document tree), check each web for any changes which may require its owner's attention, and build a special index document that lists out the attributes and connections of the web in a form that can itself be traversed as a hypertext document. This paper describes the design of MOMspider and how it was influenced by the nature of distributed hypertext maintenance and requirements for the good behavior of any web-traversing robot. It also includes discussion of the efficiency requirements for maintaining world-wide webs and proposed changes to HTML and HTTP to support distributed maintenance. The paper concludes with a short description of MOMspider's future and pointers to its freeware distribution site.
Detecting "cracks" in mental health service systems: application of network analytic techniques.

In one form or another, the fragmentation of health and human services in the community has been identified as a major impediment to effective service delivery (Agranoff & Pattakos, Cumming, 1967; Leopold & Schein, 1975; Tessler & Goldman, 1982; Turner & TenHoor, 1978). Historically, attempts to coordinate services among agencies have relied upon voluntary mechanisms that have sought to maintain agency autonomy while facilitating coordinated activity in areas where there is agreement (Litwak & Rothman, 1970). These voluntary coordination mechanisms have generally not proven effective (Warren, 1973). The failure to create better coordinated services has been attributed to excessive autonomy of service agencies (attempts to preserve prerogatives about problem definition, intervention, priority, and client disposition) and to patterns of funding (Agranoff & Pattakos, 1979; Greenley & Kirk, 1973; Levine, 1974).
Pioneer 10/11 mission results

The Pioneer 10/11 spacecraft and its scientific payload are described. The selected mission profiles and a summary of the scientific results are discussed. Results obtained during the traverse of the asteroid belt show that the particle concentration is less than had been theorized and does not present an appreciable hazard to future spacecraft passing through this previously unexplored region. Specific results from the Pioneer 10 mission and a 'first look' at the Pioneer 11 results from the 13 scientific instruments are presented. The particle and field phenomena measured within the Jovian radiation belt present a consistent picture which is, in general, an environment more severe and dynamic than that predicted by earth-based observations. Post-Jupiter trajectories for the Pioneer 10 and 11 missions are described.
Provenance of quartzite clasts in the Eocene–Oligocene Sespe Formation: Paleogeographic implications for southern California and the ancestral Colorado River

Quartzite clasts in fluvial Sespe Formation conglomerates of the Santa Monica Mountains were compared petrographically with potential source rocks in the Basin and Range and Transition Zone provinces to determine their provenance. Modal analysis indicates that Sespe orthoquartzite clasts are mainly quartzofeldspathic and derived from source rocks with craton-interior provenance. Such clasts were probably derived from Stirling Quartzite and Wood Canyon Formation sources in the northern Mojave Desert. The Mazatzal Peak Quartzite of central Arizona is the probable source of quartzolithic orthoquartzite clasts containing abundant detrital jasper grains. Sespe metaquartzite clasts are mainly from sources in the southern Mojave Desert, but some may be from the Yavapai terrane of central Arizona. The dual provenance of orthoquartzite clasts suggests that the Sespe paleoriver was a bifurcating system tapping both Mojave Desert and Sonora Desert sources. After compensating for Neogene displacement along the San Andreas fault, a paleogeographic reconstruction shows that there is a general spatial coincidence between Sespe (and other Cenozoic) paleodelta deposits around Los Angeles that contain exotic clasts, and the inferred location of the mouth of the Colorado River (assuming that it existed during the Eocene). Thus, the Colorado River may be much older than previously thought (as old as late Paleocene), and perhaps was once part of an ancient fluvial connection with the Mojave Desert interior.
Metabotropic glutamate receptor‐mediated signaling in neuroglia

Metabotropic glutamate (mGlu) receptors are G-protein-coupled receptors, which include eight subtypes that have been classified into three groups (I-III) based upon sequence homology, signal transduction mechanism and pharmacological profile. Although most studied with regard to neuronal function and modulation, mGlu receptors are also expressed by neuroglia-including astrocytes, microglia and oligodendrocytes. Activation of mGlu receptors on neuroglia under both physiologic and pathophysiologic conditions mediates numerous actions that are essential for intrinsic glial cell function, as well as for glial-neuronal interactions. Astrocyte mGlu receptors play important physiological roles in regulating neurotransmission and maintaining neuronal homeostasis. However, mGlu receptors on astrocytes and microglia also serve to modulate cell death and neurological function in a variety of pathophysiological conditions such as acute and chronic neurodegenerative disorders. The latter effects are complex and bi-directional, depending on which mGlu receptor sub-types are activated.
Human plasma-derived media supplement supports antibody production by hybridoma cells

A new, virus-inactivated, media supplement from human plasma (GEMS) has been developed which maintains hybridoma cells at a low growth rate. The rate of antibody production per cell by hybridoma cells growing in the presence of GEMS is at least equivalent to the rate of antibody production by the same cell lines growing in fetal bovine serum.
Constraint and cooperation in algebraic problem solving

Abstract Piaget (1965/1995. Sociological Studies . London: Routledge) proposes that neither the individual nor the set of individuals modify individual mental processes. Instead, what matters are the continuously modified relationships among individuals. But not all types of social interactions are sources of logical reasoning. Social interactions based on constraint only provide the individual with superficial notions, while cooperation, as a system of interpersonal actions governed by the laws of equilibrium and organized into reversible systems, allows for the development of objective and coherent system of operations. With examples of how children try to solve problems involving algebra relations and notation, we will contrast the effect of learning that results from the transmission of rules to the effect of learning that occur in cooperative interview settings. We will argue that Piaget's analysis of the role of social life and cooperation constitute a rich theoretical approach for understanding how children come to develop, understand, and use culturally developed mathematical representations.
A COUNTER HODOSCOPE SYSTEM WITH DIGITAL DATA HANDLER AND ON-LINE COMPUTER FOR ELASTIC SCATTERING AND OTHER EXPERIMENTS AT BROOKHAVEN AGS

A two-dimensional 12 x 12 counter hodoscope array composed of 30 x 2 1/2 x 1/2 in. plastic scintillation counters is described. An example of the use of a hodoscope system in high-energy elastic scattering is shown. A Cherenkov telescope selects the desired particles from the beam. Two hodoscope arrays fix the direction of the forwardscattered particle. A magnet followed by another hodoscope array determines the particles' momentum. The recoil proton is detected by two more hodoscope arrays. The data are recorded rapidly by a 96- channel digital data handler. A magnetic tape transport operates in parallel with a direct data input to the computer system. The computer can almost immediately provide printed out data and curves. Alternatively, the tape can be used to feed the computer either during the experiment if the on-line fails temporarily or later for more complicated analyses. (A.G.W.)
The Development of Symbol-Infused Joint Engagement.

Fifty-six children were observed longitudinally from 18 to 30 months of age interacting with their mothers during a Communication Play that contained 8 scenes designed to encourage interacting, requesting, commenting, and narrating. Of primary concern was how often symbols infused the child's states of engagement with people and objects and how experience in such symbol-infused states related to language acquisition. Findings indicate that symbols increasingly infuse joint engagement, and that both the timing and the trajectory vary widely among typically developing toddlers, especially during the last half of the 2nd year. Moreover, variations in amount of symbol-infused supported joint engagement may both be influenced by variations in the onset of language and contribute to differences in language facility at 30 months.
A role for stakeholder objectives in USDA Forest Service plan revisions: A case study on the White River National Forest

In August 1999, The White River National Forest, headquartered in Glenwood Springs, Colorado, USA, released a draft revised forest plan, engendering almost immediate and widespread controversy. This paper describes steps taken prior to release of the final plan to reduce the controversy by linking stakeholder objectives to plan alternatives. Information from three surveys and public comments was analyzed to characterize stakeholder objectives. A series of public meetings was conducted to validate the objectives and provide information needed to develop an objectives hierarchy, which was used to characterize means objectives that were linked to alternative plans, using associated attributes. A key finding was that stakeholders align their objectives for forest management with one of two schools of thought; one having an ecosystem conservation orientation and the other, a human use/economic sustainability orientation. The final plan, released in June 2002 received a greater level of positive reaction in the media and elsewhere.
Carpal tunnel syndrome and workers' compensation among an occupational clinic population in New York State.

Background This study evaluated the experience in the New York State workers' compensation (WC) system of 135 patients with work-related carpal tunnel syndrome diagnosed at an academic occupational medicine clinic between 1991–1994. Methods Worker's Compensation Board (WCB) records were reviewed to ascertain: (1) the proportion of WC claims that were not initially accepted (i.e., that were challenged) by the WC insurer, (2) the proportion of challenged claims ultimately decided in the claimant's favor, (3) the length of the period between case filing and claim adjudication, and (4) risk factors for claim challenge. Results Seventy-nine percent of the claims were not initially accepted by the WC insurer (challenged/no response). Of the 81 challenged/no response cases adjudicated (ruled on) at the time of the study, 96.3% were accepted as work-related. Mean time from claim initiation to adjudication was 429 days (range 58–1,617). Mean time from physician request for any treatment and WCB authorization was 226 days (range 0–1,296). Mean time from physician request for surgery authorization and WCB authorization was 318 days (range 7–595). Claims filed by non-whites, low-wage workers, and union members were significantly more likely than others to be challenged. Conclusions Patients with work-related carpal tunnel syndrome face frequent claim challenge by WC insurers in NY State, with attendant prolonged delays in adjudication and treatment authorization. Likelihood of claim rejection was strongly related to ethnicity and socio-economic status. Am. J. Ind. Med. 35:335–342, 1999. © 1999 Wiley-Liss, Inc.
A 22q11.2 deletion that excludes UFD1L and CDC45L in a patient with conotruncal and craniofacial defects.

This work was supported by National Institutes of Health grants DC02027 and HL51533 (to B.S.E, H.M., and E.H.Z.) and HD 26979 (to B.S.E.) from the Mental Retardation and Developmental Disabilities Research Center. S.C.S. is supported by Medical Genetics Research Training grant MH1-T32-GM-08638.
Novel Regulation of the Helix-Loop-Helix Protein Id1 by S5a, a Subunit of the 26 S Proteasome

Id proteins negatively regulate the dimerization, DNA binding, and biological properties of basic helix-loop-helix proteins. In a search for novel factors that interact with Id1, we identified a component of the 26 S proteasome, S5a, that has previously been implicated only in the recognition of ubiquitinated polypeptides destined for proteolysis. S5a interacts strongly with Id1, less strongly with the basic helix-loop-helix proteins MyoD and E12, and not at all with other Id proteins. S5a restores DNA binding by MyoD-Id1 and E12-Id1 heterodimers, enhances DNA binding by MyoD and E12 homodimers, and reverses Id1-mediated repression of the muscle creatine kinase promoter during myogenic differentiation. Mutagenesis experiments showed that amino acids flanking the helix-loop-helix domain plus three residues in the first helix of Id1 impart S5a recognition. This requires only the NH2-terminal half of S5a. S5a thus appears to promote the positive regulation of myogenic genes through ubiquitin-independent mechanisms involving inhibition of Id1 and the enhancement of DNA binding by MyoD and E12. This latter property may permit the selection of novel promoter binding sites during myogenesis.
Directing reaction pathways by catalyst active-site selection using self-assembled monolayers

Control of active sites of heterogeneous catalysts can lead to enhanced product selectivity. Here, the authors use self-assembled alkanethiolate monolayers with varying surface densities to tune the selectivity of hydrogenation and hydrodeoxygenation of furfural on supported palladium catalysts.
Development and investigation of a site selective palladium-catalyzed 1,4-difunctionalization of isoprene using pyridine–oxazoline ligands

Palladium-catalyzed 1,4-difunctionalizations of isoprene that produce skipped polyenes are reported. Complex isomeric product mixtures are possible as a result of the difficult-to-control migratory insertion of isoprene into a Pd–alkenyl bond, but good site selectivity has been achieved using easily accessible pyrox ligands. Mechanistic studies suggest that the control of insertion is the result of the unique electronic asymmetry and steric properties of the ligand.
International migration, remittances and economic welfare in the source country.

This article provides a formal framework for the analysis of the impact of international migration in the presence of remittances. The discussion differentiates between temporary and permanent migration and between the effects of remittances that raise investment and those that raise consumption spending in the source country. Changes in prices, income distribution and national welfare are examined.
Azoxymethane induces KI-ras activation in the tumor resistant AKR/J mouse colon.

A differential susceptibility phenotype to the organotropic colon carcinogen azoxymethane (AOM) has been described in mice. The following studies were undertaken to test the hypothesis that intraspecific susceptibility can be accounted for by the specific complement of genetic alterations acquired by precancerous colon lesions referred to as aberrant crypt foci (ACF). As an initial approach to this question, mutations in codons 12 and 13 of the Ki-ras proto-oncogene were assessed in ACF, normal-appearing AOM-treated colonic epithelium, and tumors from A/J and SWR/J (susceptible) as well as AKR/J (resistant) mice. Four-week-old male mice were injected intraperitonealy, with AOM once a week for a total of 6 wk and killed 4 and 24 wk after the last injection. DNA was isolated from microdissected tissue, and polymerase chain reaction (PCR)-amplified products of Ki-ras exon 1 (codons 12 and 13) were directly sequenced from microdissected tissues. At 4 wk after AOM exposure, there was no significant difference in the frequency of Ki-ras activation (20-33%) between the three strains. Ki-ras mRNA expression was also evaluated by reverse transcription (RT)-PCR analysis and was comparably reduced (40-50%) in all three strains at the 4 wk time point. However, Ki-ras expression returned to normal by 24 wk after treatment. Finally, to gain further insight into the molecular pathogenesis underlying this experimental tumor model, analysis of the adenomatous polyposis coli (APC) protein within the colonic epithelium was undertaken by using an immunohistochemical approach. Although the APC protein was lost to a varying extent in tumors from A/J and SWR/J mice, the full-length form of the protein was still present in precancerous ACF isolated from each of the three strains, regardless of the degree of dysplasia of the lesion. A further molecular genetic analyses of ACF will be required to gain a more complete understanding of the molecular basis of tumor susceptibility phenotype in this murine model.
Nephron obstruction in nordihydroguaiaretic acid-induced renal cystic disease.

Nephron obstruction in nordihydroguaiaretic acid-induced renal cystic disease. Studies were performed to characterize conditions in rat kidneys whose nephrons were made cystic by feeding 2% nordihydroguaiaretic acid (NDGA) to the animals. Using two micropipettes, we monitored intratubular hydrostatic pressures while perfusing single surface nephrons in NDGA-exposed (5 to 7 weeks) and normal rat kidneys. The introduction of 50 nl of Ringers solution labeled with 3 H-inulin at a flow rate of 25 nl/min was associated with a significant mean (± SEM) increase (167 ± 61%; P 3 H-inulin excreted in 40 min from cystic (4.0 ± 2.0%) was less than that excreted from either nondilated (19 ± 7%; P 3 H-inulin ratios in additional rats were similar among all groups of tubules. Concluding that these data reflected increased resistance to outflow from cystic nephrons, we examined these and additional NDGA-exposed (1 to 24 weeks) kidneys. 3 H-thymidine radio-autography demonstrated maximum collecting tubular cell hyperplasia (13% labeling) at 2 to 3 weeks of NDGA-exposure. Microscopy and microdissection demonstrated tiny mural polyps along outer medullary segments of collecting tubules. Thirteen tubules were traced to their outlets; polyps impinging on outflow lumens were found in all 13 instances. We conclude that partial nephron obstruction exists in NDGA-exposed kidneys and that obstruction is a likely contributor to cyst formation in this model. Obstruction nephronique dans la maladie kystique du rein determinee par l'acide nordihydroguaiaretique. Cette etude a porte sur des reins de rats dont les nephrons ont ete rendus kystiques par l'addition a l'alimentation d'acide nordihydroguaiaretique (NDGA) a 2%. Au moyen de deux micropipettes les pressions hydrostatiques intratubulaires ont ete enregistrees pendant la perfusion de nephrons superficiels chez des rats exposes a NDGA (5 a 7 semaines) et des rats normaux. L'introduction de 50 nl de Ringer contenant de l'inuline 3 H au debit de 25 nl/min est associee a une augmentation significative (167 ± 61%; P 3 H excretee en 40 min par les nephrons kystiques (4,0 ± 2,0%) est inferieure a celle excretee par les nephrons non dilates (19 ± 7%; P 3 H ont montre une hyperplasie maximale (13% de marquage) des cellules tubulaires des collecteurs entre 2 et 3 semaines d'exposition a NDGA. La microscopie et la microdissection ont montre des petits polypes muraux le long des segments medullaires externes des tubes collecteurs. Treize tubules ont ete suivis jusqu'a leurs terminaisons et dans les 13 cas des polypes genant l'ecoulement ont ete trouves. Nous concluons qu'il existe une obstruction nephronique partielle dans les reins exposes a NDGA et que cette obstruction contribue vraisemblablement a la formation de kystes dans ce modele.
Social status regulates kisspeptin receptor mRNA in the brain of Astatotilapia burtoni.

The brain controls reproduction in response to relevant external and internal cues. Central to this process in vertebrates is gonadotropin-releasing hormone (GnRH1) produced in neurons of the hypothalamic-preoptic area (POA). GnRH1 released from the POA stimulates pituitary release of gonadotropins, which in males causes sperm production and concomitant steroid hormone release from the testes. Kisspeptin, a neuropeptide acting via the kisspeptin receptor (Kiss1r), increases GnRH1 release and is linked to development of the reproductive system in mammals and other vertebrates. In both fish and mammals, kiss1r mRNA levels increase in the brain around the time of puberty but the environmental and other stimuli regulating kisspeptin signaling to GnRH1 neurons remain unknown. To understand where kiss1r is expressed and how it is regulated in the brain of a cichlid fish, Astatotilapia burtoni, we measured expression of a kiss1r homolog mRNA by in situ hybridization and quantitative reverse transcription-PCR (qRT-PCR). We found kiss1r mRNA localized in the olfactory bulb, specific nuclei in the telencephalon, diencephalon, mesencephalon, and rhombencephalon, as well as in GnRH1 and GnRH3 neurons. Since males’ sexual physiology and behavior depend on social status in A. burtoni, we also tested how status influenced kiss1r mRNA levels. We found higher kiss1r mRNA levels in whole brains of high status territorial males and lower levels in low status non-territorial males. Our results are consistent with the hypothesis that Kiss1r regulates many functions in the brain, making it a strong candidate for mediating differences in reproductive physiology between territorial and non-territorial phenotypes.
A Free Energy Comparison of the Human Sm Protein Complexes B/D3 and D3/B

Molecular dynamics simulations were carried out for the human Sm proteins B and D3, and two different configurations of their complexes, B/D3 and D3/B, to investigate the structures of possible sub-complexes used for assembly of the ring structure comprised of the seven Sm proteins. Comparison of the free energy for the two sub-complexes revealed that the D3/B configuration, in which the β4 strand of B interacts with the β5 strand of D3 protein, is energetically preferred relative to the B/D3 configuration. The direct interaction energy in vacuo and the solvation energy provided the largest contributions to the free energy. The torsional low-frequency vibration modes provided the largest contribution to the entropic terms due to complex formation, although the single mode also gave a small contribution. Determining the configuration of the D3/B sub-complex provides powerful support for a proposed binding mechanism of the Sm proteins on snRNA.
Periventricular system lesions and stimulation-produced analgesia.

Abstract Three areas within the periventricular system were studied: caudal periaqueductal gray (PAG), rostral PAG, and caudal midline thalamus. Rats were chronically prepared with a bipolar stimulating electrode in one of these areas and two lesion electrodes in another. Current thresholds for stimulation-produced analgesia in the tail-flick test were assessed. Then, lesions were made and thresholds for analgesia re-assessed. Destruction of the caudal PAG consistently produced large increases in thresholds for analgesia at rostral stimulation sites; however, destruction of the rostral areas did not affect thresholds at caudal PAG sites. Lesions in all 3 areas yielded significant reductions in baseline (pre-brain stimulation) tail-flick latencies. Both sham lesioned control animals and animals with small lesions maintained stable baseline latencies and analgesia thresholds. The data support the view that all 3 brain areas studied contribute to the same pain-inhibitory system. They further suggest that stimulation at rostral sites activates elements which connect to or pass through the caudal PAG.
Single-Cysteine Substitution Mutants at Amino Acid Positions 306−321 in Rhodopsin, the Sequence between the Cytoplasmic End of Helix VII and the Palmitoylation Sites: Sulfhydryl Reactivity and Transducin Activation Reveal a Tertiary Structure†,‡

As sensors for structure at the cytoplasmic face of rhodopsin, single-cysteine substitution mutants have been previously studied in the regions connecting helices III and IV and helices V and VI. In this paper we report on single-cysteine substitution mutants at amino acid positions 306-321, comprising the cytoplasmic sequence between helix VII and the palmitoylation sites in rhodopsin. The cysteine opsin mutants were expressed in COS-1 cells and on treatment with 11-cis-retinal all formed the characteristic rhodopsin chromophore. Cysteines at positions 306-316 and 319 reacted in the dark with the thiol-specific reagent 4, 4'-dithiodipyridine (4-PDS) but showed a wide variation in reactivity. Cysteines at positions 317, 318, 320, and 321 showed no reaction with 4-PDS. The mutants on illumination also showed wide variations in activating GT. The mutant Y306C showed almost no GT activation, I307C and N310C were poor, and the activity of the mutants M309C, F313C, and M317C was also reduced relative to WT. The results suggest that the region comprising amino acids 306-321 is a part of a tertiary structure and that specific amino acids in this region on light-activation participate in the interaction with GT.
Layer Specific Sharpening of Frequency Tuning by Selective Attention in Primary Auditory Cortex

Recent electrophysiological and neuroimaging studies provide converging evidence that attending to sounds increases the response selectivity of neuronal ensembles even at the first cortical stage of auditory stimulus processing in primary auditory cortex (A1). This is achieved by enhancement of responses in the regions that process attended frequency content, and by suppression of responses in the surrounding regions. The goals of our study were to define the extent to which A1 neuronal ensembles are involved in this process, determine its effect on the frequency tuning of A1 neuronal ensembles, and examine the involvement of the different cortical layers. To accomplish these, we analyzed laminar profiles of synaptic activity and action potentials recorded in A1 of macaques performing a rhythmic intermodal selective attention task. We found that the frequency tuning of neuronal ensembles was sharpened due to both increased gain at the preferentially processed or best frequency and increased response suppression at all other frequencies when auditory stimuli were attended. Our results suggest that these effects are due to a frequency-specific counterphase entrainment of ongoing delta oscillations, which predictively orchestrates opposite sign excitability changes across all of A1. This results in a net suppressive effect due to the large proportion of neuronal ensembles that do not specifically process the attended frequency content. Furthermore, analysis of laminar activation profiles revealed that although attention-related suppressive effects predominate the responses of supragranular neuronal ensembles, response enhancement is dominant in the granular and infragranular layers, providing evidence for layer-specific cortical operations in attentive stimulus processing.
Identification of Phenotypic State Transition Probabilities in Living Cells

Living cells stochastically switch their phenotypic states in response to environmental cues to maintain persistence and viability. Estimating the state transition probabilities from biological observations of cell populations gives valuable insight to the underlying processes, and gives insights as to how the transition statistics are influenced by external factors. In this work, we present two Bayesian estimation approaches. The first is applicable when individual cell state trajectories are observed. The second approach is applicable when only aggregate population statistics are available. Estimation of transition probabilities when individual cell state trajectories are available is a straightforward problem, whereas estimation from only aggregate statistics can be computationally expensive. In the latter case, we present an algorithm that relies on three key ideas to cut down computational time: i) approximating high-dimensional multinomial distributions with multi-variate Gaussians, ii) employing Monte-Carlo techniques to efficiently integrate over high dimensional spaces, and iii) explicitly incorporating sampling constraints by computing lower dimensional distributions over the constrained variable. Simulation results demonstrate the viability of the algorithm.Copyright © 2009 by ASME
Prophylactic effects of caprine serum factor (CSF‐I) in mice infected with Salmonella typhimurium

Administration of caprine serum fraction–immunomodulator (CSF-I) resulted in an enhanced survival rate in female Swiss Webster mice infected with approximately 5,000 colony-forming units of Salmonella typhimurium. The prophylactic benefit of CSF-I resulted in a significant reduction in mortality of treated mice vs. control mice. Dependent upon the inoculum’s titer, 80–90% of the control group was lost due to salmonellosis by 8 days postchallenge. A single 0.1 ml (3 mg) subcutaneous dose of CSF-I given 1 day before challenge improved the survival by 70–80% and dramatically reduced the presence of S. typhimurium in splenic tissue. No prophylactic benefits were observed if CSF-I was given 4 days in advance of the pathogenic challenge. The prophylactic benefits of CSF-I developed in a dose-dependent manner. CSF-I enhances the ability of the host to withstand and survive the challenge of an infectious agent. Drug Dev. Res. 54:45–51, 2001. © 2001 Wiley-Liss, Inc.
American Jews and the Israeli–Palestinian conflict: A psychodynamically based understanding

Many American Jews who endorse progressive values are reluctant to express legitimate criticism of Israel and tend to hold Palestinians and their leaders fully responsible for the conflict. This article offers a number of explanations for the psychological forces at play for American Jews in this charged and important issue and suggests some possible mechanisms that may facilitate a more balanced and nuanced perspective to address the vicious cycle of this conflict. The paper ends by detailing a psychologically informed path that may help American Jews and other concerned citizens to challenge more comfortably current views on Israel and to advocate more actively for mutual collaboration and compromise in peace efforts.
Reactor technique for prediction of dissolved oxygen profiles in streams

A laboratory experiment that can provide significant design information to an environmental scientist or engineer can be performed rapidly and inexpensively with an open stirred-reactor that simulates a receiving stream. The experiment requires only a laboratory beaker, stirring apparatus, dissolved oxygen meter, wastewater sample and receiving stream sample. Wastewater and receiving stream water are mixed in the laboratory beaker and are stirred at different speeds to obtain different reaeration rates. A probe is used to monitor dissolved oxygen concentrations of the mixture. A series of experiments were performed at different waste loadings and different reaeration rates. Sample results are shown which indicate the depletion of dissolved oxygen due both to carbonaceous and nitrogeneous oxygen demands. This technique can be used to predict response of a receiving stream to a waste discharge without use of a mathematical model. Results are shown which illustrate the difference between experimental results and theoretical predictions.
Modeling Lilac development

Lilac ‘Red Rothomagensis’ is used as indicator plant in phenological studies in the Northeastern United States. Geophysical variables — latitude, longitude, elevation- were used in addition to the date of one phenophase (first leaf) to predict the date of subsequent phenophases (first flowers, full bloom) of the indicator plant. In 5 years out of 7 the mean difference in the study area between actual and predicted dates was no larger than 2 days with standard deviations between 4 and 6 days. Little consistency existed from year to year in overestimation or underestimation at most observation sites.
Increased intestinal permeability: implications for thoracoabdominal aneurysm repair.

Coagulopathy and massive bleeding plays a major role in the mortality of thoracoabdominal aneurysm repair. Increasing supraceliac aortic cross-clamp time from 0 to 90 minutes increases the degree of disseminated intravascular coagulation, which occurs as a result of occlusion and reperfusion of the superior mesenteric artery. The purpose of this study was to investigate the mechanism of the superior mesenteric artery reperfusion disseminated intravascular coagulation. Twenty dogs were divided into four groups: cross-clamp time of 30 minutes; cross-clamp time of 60 minutes; cross-clamp time of 90 minutes; and control. Permeability was determined by lactulose/mannitol absorption. The venous effluent was sampled for endotoxin, potassium, bacteria, and pH every hour and urine was collected for six hours. Lactulose absorption was significantly higher in all of the experimental groups. There was increased permeability in the 60 and 90 minute groups which correlated significantly with time. Venous endotoxin, potassium, and blood cultures for bacteria did not change significantly. The pH was significantly lower every hour for six hours in the 90 minute group. These data suggest that intestinal permeability is increased with supraceliac aortic clamping and can be kept to a minimum for clamp times of under one hour.