cssi/SciSciGPT-SciSciNet huggingface dataset:
The TβR-I pre-helix extension is structurally ordered in the unbound form and its flanking prolines are essential for binding.

Transforming growth factor β isoforms (TGF-β) are among the most recently evolved members of a signaling superfamily with more than 30 members. TGF-β play vital roles in regulating cellular growth and differentiation, and they signal through a highly restricted subset of receptors known as TGF-β type I receptor (TβR-I) and TGF-β type II receptor (TβR-II). TGF-β's specificity for TβR-I has been proposed to arise from its pre-helix extension, a five-residue loop that binds in the cleft between TGF-β and TβR-II. The structure and backbone dynamics of the unbound form of the TβR-I extracellular domain were determined using NMR to investigate the extension's role in binding. This showed that the unbound form is highly similar to the bound form in terms of both the β-strand framework that defines the three-finger toxin fold and the extension and its characteristic cis-Ile54-Pro55 peptide bond. The NMR data further showed that the extension and two flanking 310 helices are rigid on the nanosecond-to-picosecond timescale. The functional significance of several residues within the extension was investigated by binding studies and reporter gene assays in cultured epithelial cells. These demonstrated that the pre-helix extension is essential for binding, with Pro55 and Pro59 each playing a major role. These findings suggest that the pre-helix extension and its flanking prolines evolved to endow the TGF-β signaling complex with its unique specificity, departing from the ancestral promiscuity of the bone morphogenetic protein subfamily, where the binding interface of the type I receptor is highly flexible.
How immune mechanisms are affected by pregnancy

Pregnancy requires physiologic adaptations in all maternal systems, including the immune system. This process is complex and includes modifications at different levels and compartments of the maternal immune system. Although many of these changes are only partially explored and understood, recent investigations have showed that during pregnancy maternal circulating immune cells undergo modifications in cell counts, phenotypes, functions and ability to produce soluble factors, such as cytokines. The ultimate goal is to establish and maintain a successful pregnancy, which involves a state of selective immune tolerance, immunosuppression and immunomodulation in the presence of a strong anti-microbial immunity. The mammalian immune system has evolved to coexist with these needs by down-regulating potentially dangerous T-cell-mediated immune responses, while activating certain components of the innate immune system, such as monocytes and neutrophils. This unique dysregulation between different components of the immune system plays a central role in the maternal adaptation to pregnancy.
Sylwia Wojciechowska. Conceptual Metonymy and Lexicographic Representation.

Review of Sylwia Wojciechowska . Conceptual Metonymy and Lexicographic Repre­sentation.
Conductivity and Hardness Changes in Aged Compacts

Batches of sodium, potassium, and ammonium chloride tablets containing no excipients and spray-dried lactose tablets containing 0.5% magnesium stearate were stored at 20 and 76% relative humidity. Electrical resistance and hardness measurements were made within 1 hr after compression and at intervals during a 45-day period. Hardness values of sodium, potassium, and ammonium chloride tablets stored at 20% relative humidity increased from 70 to 200% at 45 days, while conductances decreased 10-fold. Tablets stored at 76% relative humidity showed no increases or slight decreases in hardness with slight increases in conductance. Lactose tablets decreased slightly in hardness with corresponding increases in conductance.
Chemical reaction of DNA with cross-linking agents: Influences of base permutation on chemical reactivity

Abstract Certain psoralens can photoreact with the pyrimidine bases of DNA and form interstrand cross-links. In this communication, theoretical mechanism of the photoreaction of DNA with psoralens in the presence of near-ultraviolet light (320–400 nm, u.v.-A) is diagrammatically and quantitatively presented. The number of the receptor binding sites, the theorized photoreaction sites, can be estimated from the base composition of DNA if the extent of the photoreactivity of cytosine and the possibly steric hindrance effects of DNA double helix in photoreactivity can be experimentally determined. The photoreactivity of DNA can be expressed by the number of psoralens photobound. It is predicted that the photoreactivity of DNA is less than, or at most equal to, the number of receptor binding sites depending on the number of cross-links formed during photoreaction. The number of cross-links formed is the consequence of the base permutation which determines the constitution of cross-linking sites, and of the manners of psoralens intercalated in the stacked DNA bases. In addition, the formation of the cross-linking sites is also influenced by the photoreactivity of cytosine which is presently not understood. It is likely that theoretical mechanism of the chemical reaction of DNA with other cross-linking agents can be similarly hypothesized.
Mutational spectra of human cancer

The purpose of this review is to summarize the evidence that can be used to reconstruct the etiology of human cancers from mutations found in tumors. Mutational spectra of the tumor suppressor gene p53 (TP53) are tumor specific. In several cases, these mutational spectra can be linked to exogenous carcinogens, most notably for sunlight-associated skin cancers, tobacco-associated lung cancers, and aristolochic acid-related urothelial tumors. In the TP53 gene, methylated CpG dinucleotides are sequences selectively targeted by endogenous and exogenous mutagenic processes. Recent high-throughput sequencing efforts analyzing a large number of genes in cancer genomes have so far, for the most part, produced mutational spectra similar to those in TP53 but have unveiled a previously unrecognized common G to C transversion mutation signature at GpA dinucleotides in breast cancers and several other cancers. Unraveling the origin of these G to C mutations will be of importance for understanding cancer etiology.
A contracted bromine basis set for use in calculation of molecular energies

A contracted [9s6p2d] basis set derived from Dunning's (14s11p5d) primitive Gaussian set for bromine has been used in ab initio molecular orbital calculations of the dissociation energies of HBr, CH 3 Br, and Br 2 , the ionization potentials of Br and HBr, and the electron affinity of Br. The calculated energies are within 0.1 eV of the experimental values. This is similar to the accuracy obtained in a previous study, also using a contracted [9s6p2d] basis set, of the dissociation and ionization energies of the GeH n , AsH n , and SeH n hydrides
Commentary: A family of UDP-GlcNAc/MurNAc: polyisoprenol-P GlcNAc/MurNAc-1-P transferases

UDP-GlcNAc:dolichol-P GlcNAc-1-P transferase (GPT) catalyses the transfer of GlcNAc-1-P from UDP-GlcNAc to dolicholP to form GlcNAc-P-P-dolichol. In essence, GPT performs the committed reaction of asparagine-linked glycosylation (Lehrman, 1991), and GPT activity has been identified in all eukaryotic cells examined to date. The enzyme has been reported purified to homogeneity from bovine mammary gland (Shailubhai et ai, 1988) and its gene or cDNA has been isolated from the yeast Saccharomyces cerevisiae (Rine et ai, 1983; Hartog and Bishop, 1987), Leishmania amazonesis (Liu and Chang, 1992), Chinese hamster ovary cells (Scocca and Krag, 1990; Zhu and Lehrman, 1990) and mouse mammary gland (Rajput et ai, 1992). A recent search of the SwissProt protein data base (release 28) with FastA (Genetics Computer Group, University of Wisconsin) revealed a 24.4% identity in a 287 amino acid overlap between hamster GPT and UDP-N-acetylmuramoyl-pentapeptide: undecaprenol-P phospho-JV-acetylmuramoyl-pentapeptide transferase of Af-Acetylmuramic acid (MurNAc) is similar to GlcNAc; in MurNAc, the 3-position of the sugar ring is modified with a lactic acid residue coupled through its hydroxyl group. In UDPMurNAc-pentapeptide, a pentapeptide is coupled through the carboxyl group of the lactic acid residue. Undecaprenol-P contains 11 unsaturated isoprene groups. By comparison, in dolichol-P the number of isoprene units can vary [typically 11-12 in trypanosomes, 14-16 in yeast and 17-19 in rodents; see Datta and Lehrman (1993) and references therein] and the a-isoprene unit (to which the phosphate is attached) is saturated. This prompted a re-examination of the protein sequence similarities between eukaryotic GPT and prospective prokaryotic counterparts. In these comparisons, only GPT sequences found in both hamster (Zhu and Lehrman, 1990) and yeast (Hartog and Bishop, 1987), and thus conserved in the eukaryotic enzymes, were considered. In addition to the B.subtilis mraY protein (Daniel and Errington, 1993), sequences for E.coli mraY protein (Ikeda et at, 1991) and E.coli rfe protein (UDP-GlcNAc:undecaprenol-P GlcNAc-1-P
Musculoskeletal Ultrasound: How to Evaluate for Morton's Neuroma

AJR:193, September 2009 OBJECTIVE The use of musculoskeletal ultrasound has been increasing. Ultrasound is well-established as a safe, cost-effective imaging tool in diagnosing and treating common musculoskeletal disorders. A musculoskeletal ultrasound program can enhance radiology practices by creating an environment that increases both patient and clinician satisfaction. The purpose of this new video article is to show that ultrasound is well-suited to evaluate for Morton’s neuroma. CONCLUSION The presentation will introduce the ultrasound appearance of Morton’s neuroma, give examples of how to differentiate it from intermetatarsal bursitis, and discuss a concise protocol used in the diagnosis of Morton’s neuroma or other causes of forefoot pain. Lastly, ultrasound’s real-time capability will be highlighted during the demonstration of a standardized ultrasound-guided injection protocol used to treat either Morton’s neuroma or intermetatarsal bursitis. Musculoskeleta l Imaging • Video Ar t ic le
Cryopreservation of Panax ginseng cells.

The impacts of cryoprotectants (CP) and cell status during the growth cycle on Panax ginseng cell viability during cryopreservation were investigated. The ginseng cells used had a 5–7 times proliferation rate (compared with inoculum) in 2–3 weeks and were subcultured at 2- and 4-week intervals in liquid and on solid media, respectively. After testing various CP solutions of glycerol, dimethylsulphoxide, ethylene glycol and sucrose, a combination of 10% (v/v) glycerol and 4% (w/v) sucrose was selected for its least cytotoxicity and highest cell viability after thawing. With this CP solution, cells throughout the growth cycle exhibited a ‘U’-shaped fluctuation of post-thaw cell viability. The highest viability (86.5%) occurred during the lag phase from cells already maintained in suspension culture and then in the late exponential phase (61.7%); the lowest level of 15.4% was in the mid-exponential phase. Callus freshly transferred to liquid medium showed a less obvious fluctuation pattern. The recovered cells were brown-to-reddish at first and gradually returned to a light yellow colour after several subcultures.
Plato on Pure Pleasure and the Best Life

AbstractIn the Philebus, Socrates maintains two theses about the relationship between pleasure and the good life: (1) the mixed life of pleasure and intelligence is better than the unmixed life of intelligence, and: (2) the unmixed life of intelligence is the most divine. Taken together, these two claims lead to the paradoxical conclusion that the best human life is better than the life of a god. A popular strategy for avoiding this conclusion is to distinguish human from divine goods; on such a reading, pleasure has merely instrumental value, and it benefits human beings only as a result of their imperfect nature. I argue that certain ‘pure’ pleasures are full-fledged, intrinsic goods in the Philebus, which are even worthy of the gods (thus Socrates ultimately rejects thesis 2). This positive evaluation of pure pleasure results from a detailed examination of pleasure, which reveals that different types of pleasures have fundamentally different natures.
Defining Perioperative Mortality after Open and Endovascular Aortic Aneurysm Repair in the US Medicare Population

Background Perioperative mortality is reported after abdominal aortic aneurysm (AAA) repair, but there is no agreed upon standard definition. Often, 30-day mortality is reported because in-hospital mortality may be biased in favor of endovascular repair given the shorter length of stay. However, the duration of increased risk of death after aneurysm repair is unknown. Study Design We used propensity score modeling to create matched cohorts of US Medicare beneficiaries undergoing endovascular (n = 22,830) and open (n = 22,830) AAA repair from 2001 to 2004. We calculated perioperative mortality using several definitions including in-hospital, 30-day, and combined 30-day and in-hospital mortality. We determined the relative risk (RR) of death after open compared with endovascular repair as well as the absolute mortality difference. To define the duration of increased risk we calculated biweekly interval death rates for 12 months. Results In-hospital, 30-day, and combined 30-day and in-hospital mortality for open and endovascular repair were 4.6% versus 1.1%, 4.8% versus 1.6%, and 5.3% versus 1.7%, respectively. The absolute differences in mortality were similar, at 3.5%, 3.2%, and 3.7%. The RRs of death (95% confidence interval) were 4.2 (3.6 to 4.8), 3.1 (2.7 to 3.4), and 3.2 (2.8 to 3.5). Biweekly interval death rates were highest during the first month after endovascular repair (0.6%) and during the first 2.5 months (0.5% to 2.1%) after open repair. After 2.5 months, rates were similar for both repairs ( Conclusions In-hospital mortality comparisons overestimate the benefit of endovascular repair compared with 30-day or combined 30-day and in-hospital mortality. The total mortality impact of AAA repair is not realized until 3 months after repair and the duration of highest mortality risk extends longer for open repair.
Synthesis of some esters of hippuric acid, and their hydrolysis by α-chymotrypsin

Abstract Methods are outlined for the synthesis of methyl, ethyl, propyl, isopropyl, and butyl hippurates. By heating the reactants in an atmosphere of hydrogen in the absence of a catalyst, contact of the esters with acid or alkali, which might attack both the ester and amide linkages present, is avoided. The conventional kinetic constants for the hydrolysis of the above esters by α-chymotrypsin were determined. The results are interpreted to indicate that in this series, the hydrolysis of hippuryl α-chymotrypsin is not the rate-limiting step. The variation of the maximum velocity with alcohol chain length of the ester is shown to be the variation of the decomposition of enzyme-substrate complex to alcohol and acyl enzyme with alcohol chain length, provided, of course, that the reaction does proceed by acylation of the enzyme. The similarity between acetal formation and the decomposition of the enzyme-substrate complex is mentioned. In order to explain the variation of the apparent association constant with alcohol chain length, it is suggested that a substrate solution term may contribute to this association constant.
Comparative Renal and Hepatotoxicity of Halomethanes: Bromodichloromethane, Bromoform, Chloroform, Dibromochloromethane and Methylene Chloride

The renal and hepatotoxicities of five selected halomethanes, which are drinking water contaminants, were evaluated following a 14-day exposure. Bromodichloromethane, bromoform, chloroform, dibromochloromethane and methylene chloride were administered at three dose levels. Toxicity was evaluated by measuring changes in total body weight, uptake of p-aminohippurate into renal cortical slices, blood urea nitrogen, serum creatinine, and serum glutamate-pyruvate transaminase levels and by performing a histopathologic examination of liver and kidney tissues. Dose-related effects on the liver and kidney were detected with the uptake of p-aminohippurate into kidney slices and with the histopathologic evaluation of tissues. Treatment-related effects seen in the methylene chloride exposed mice were less pronounced as compared to the other halomethane treatment groups. In general, histopathological changes were the most sensitive indicators of both liver and kidney damage.
Escape of Captured Dungeness Crabs from Commercial Crab Pots in the Columbia River Estuary

Abstract Escape of Dungeness crabs (Cancer magister) from baited commercial crab pots in the Columbia River estuary was examined. During a 28-day period (12 October-10 November 1982), 185 male crabs were captured and tagged. Sixty percent of the crabs escaped, the majority within 2 days. Size, leg loss, and leg regeneration were not significant factors in escapement.
Gamma Knife radiosurgery to four or more brain metastases in patients without prior intracranial radiation or surgery.

Data on stereotactic radiosurgery (SRS) for four or more metastases are limited. Existing studies are confounded by significant proportions of patients receiving prior whole-brain radiation therapy (WBRT) or concurrent WBRT with SRS. Furthermore, published results disagree about the impact of tumor volume on overall survival. A retrospective review identified 38 patients without prior intracranial radiation or surgery who received Gamma Knife (GK) as sole treatment to ≥4 brain metastases in a single session. Twenty-eight cases with follow-up imaging were analyzed for intracranial progression. Prognostic factors were examined by univariate (log-rank test) and multivariate (Cox proportional hazards model) analyses. Common primary tumors were non-small cell lung (45%), melanoma (37%), and breast (8%). Cases were recursive partitioning analysis class II (94%) or III (6%). Patients harbored a median five tumors (range 4–12) with median total tumor volume of 1.2 cc. A median dose of 21 Gy was prescribed to the 50% isodose line. Patients survived a median 6.7 months from GK. Local treatment failure occurred in one case (4%) and distant failure in 22 (79%). On multivariate analysis, total tumor volume ≥3 cc was significantly associated with distant failure and worsened overall survival (P = 0.042 and 0.040). Fourteen patients (37%) underwent salvage WBRT at a median 10.3 months from GK and seven patients received repeat GK. GK as sole initial treatment for four or more simultaneous metastases spares some patients WBRT and delays it for others. Increased total tumor volume (≥3 cc) is significantly associated with worsened overall survival.
Front-tracking image reconstruction algorithm for EIT-monitored cryosurgery using the boundary element method

The effectiveness of cryosurgery, treatment of tumors by freezing, is highly dependent on knowledge of transient freezing extent, and therefore relies heavily on real-time imaging techniques for monitoring. Electrical impedance tomography (EIT) holds much promise for this application. In cryosurgery there is a three order of magnitude change in impedance across the freezing boundary and there is a priori knowledge of the freezing origin. Furthermore, an EIT image of the tissue can be done prior to the cryosurgery. In this study, we have developed an EIT front tracking reconstruction algorithm which takes advantage of these particular attributes of cryosurgery. The method tracks the freezing interface rather than the impedance distribution in the freezing tissue. In addition to drastically reducing the number of parameters needed to define the image, the computational complexity is further reduced by using the more appropriate boundary element method (BEM) for solution to the forward problem. The front-tracking method was found to converge rapidly and accurately to a variety of simulated phantom images.
Adaptive concentration control of cooling and antisolvent crystallization with laser backscattering measurement

This paper presents a thorough simulation and experimental evaluation of the concentration control approach for batch and semibatch crystallization. The sensitivity of concentration feedback control is assessed in the case of various disturbances that result in excessive nucleation events. The enhanced robustness of the concentration control is demonstrated against the widely used direct operation approach, which directly implements the temperature or antisolvent addition rate versus time. An adaptive concentration control strategy is proposed that employs measurement of the number of particle counts per unit time provided by in situ laser backscattering, to detect the onset of nucleation and adapt the operating curve accordingly, further enhancing the robustness of the approach. Simulation and experimental results indicate that adaptive concentration control is robust to variations in the nucleation, growth, or dissolution rates due to scale-up or other changes in the process conditions.
Isolation of "Candidatus Rickettsia andeanae" (Rickettsiales: Rickettsiaceae) in embryonic cells of naturally infected Amblyomma maculatum (Ixodida: Ixodidae).

ABSTRACT The Gulf Coast tick, Amblyomma maculatum Koch, has become increasingly important in public health for its role as a vector of the recently recognized human pathogen, Rickettsia parkeri. More recently, these ticks were also found to harbor a novel spotted fever group rickettsia, “Candidatus Rickettsia andeanae.” First identified in Peru, and subsequently reported in ticks collected in the United States, Chile, and Argentina, “Ca. R. andeanae” remains largely uncharacterized, in part because of the lack of a stable isolate. Although the isolation of “Ca, R. andeanae” was recently described in DH82, Vero, and Drosophila S2 cells, its stability in these cell lines was not shown. To evaluate “Ca. R. andeanae” transmission and pathogenicity in vertebrates, as well as further describe biological characteristics of this candidate species to fulfill criteria for its establishment as a new species, availability of a stable isolate is essential. Here we describe the propagation of “Ca. R. andeanae” by using...
Crosstalk between Estrogen Receptor alpha 36, a Dominant Extra-Nuclear ER, and HER2 Promotes Tumor Cell Survival in Breast Cancer.

The ER-α36 protein is a 36kDa novel splice variant of the full length 66kDa ER-α. ER-α36 lacks both transcriptional activation domains of ER-α66 but retains the DNA-binding domain and partial dimerization and ligand-binding domains. It has been shown that ER-α36 could trigger membrane-initiated signaling in ER-α36 over-expressing 293 cells, suggesting that ER-α36 might have functions linked with activation of intracellular signaling.To further explore the mechanism(s) of ER-α36 activation of intracellular signaling, in particular the possible relationship between ER-α36 and HER2 in breast cancer, we performed a pilot study. First, we examined the correlation between ER-α36 and HER2 by immunohistochemistry (IHC) using a specific anti-ER-α36 antibody designed against a unique epitope located in the C-tail of ER-a36 which is not present in ER-α66. The results showed that the expression of ER-α36 was highly associated with HER2 in a cohort of 249 breast tumors (P Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2121.
VARIABILITY IN THE URINARY EXCRETION OF GROWTH HORMONE (GH) AND CREATININE IN CHILDHOOD

As a basis for assessment of the clinical validity of urinary GH measurements in children, the variability in renal handling of GH was compared to that of creatinine in 93 healthy children (aged 4-16 years), 20 of normal stature and 73 with growth disorders. 10 were classified as GH deficient (GHD), 48 as short normal (SN) and 15 had Turner syndrome (TS). 5 overnight urine samples were collected over 2 weeks, and the variability of excretion expressed as a coefficient of variation (CV) of the total overnight amount of GH or creatinine. There was considerable night to night variability in the excretion of both substances: * p<0.05 compared to Normal + SN, #p<0.05 compared to Normal. Assay variation rather than a change in renal protein handling accounted for the large variation in low uGH concentrations, thus contributing to the high uGH CV of the GHD group. Increasing the number of samples collected (upto 5) decreased the expected sample variation (error) for uGH but not significantly in all groups, and reduced the convenience and practicality of the test. These results indicate that variation in GH and creatinine excretion is considerable in both normal children and those with growth disorders. The use of multiple samples (upto 5) does not significantly reduce the variability inherent in uGH measurement.
Thermal and mechanical stresses in nuclear reactor vessels

Abstract This paper is concerned with stress and deformation analysis of a circular cylindrical, thin, elastic shell, representing a nuclear reactor vessel, with an insulated cutout of arbitrary shape subjected to mechanical and thermal loads. The analysis is based on the method of superposition. The actual stresses in the shell may be considered as the sum of the following two parts: 1. (a) Stresses caused by the given heat flow and mechanical loads in a similar shell without a hole (nominal stress solution); 2. (b) Stresses in the shell caused by edge loads at the boundary of the hole (residual stress solution). The governing equations of this problem are the so-called Morley equations, which have nearly the same simple form as the well-known Donnell equations but include no other assumptions than those of the linear thin-shell theory. The mechanical loading consists of any loading normal to the shell surface. The thermal loading is represented by the middle surface temperature distribution and by specified temperatures on the inner and outer surfaces of the shell. The middle surface temperature distribution is determined by taking into account the temperature boundary conditions at both ends of the shell and the hole geometry. It should be mentioned that cutout causes the disturbance in the heat flow and therefore middle surface temperature distribution differs considerably from the no-hole case. The arbitrary hole is represented either by a polynomial of up to the tenth power in the shell coordinates, or it is specified point by point in the shell coordinates along with the value of the curve tangent at those points. The nominal stress solution is obtained in Fourier-series form from the Morley's equations. The method of point matching in the sense of least squares is used to obtain the middle surface temperature distribution and the residual stress solution. Thus a very general computer program, based on the explained formulation has been developed. This program is capable of handling a large number of cases and it has been evaluated by comparing the numerical results of some specific cases (the cases of circular and elliptic holes) with the available experimental results.
TISSUE-SPECIFIC PROTEIN-DNA INTERACTIONS OF THE MOUSE PROTAMINE 2 GENE PROMOTER

During spermiogenesis, the haploid phase of spermatogenesis, the genome is packaged into a highly compacted form and this process requires replacement of histones by protamines. In the mouse, protamines are encoded by two genes, which are transcriptionally regulated in testis. To understand the regulation of transcription of the mouse protamine 2 (mP2) gene, the tissue-distribution of sequence-specific interactions between nuclear proteins and promoter DNA sequences have been analyzed. Protein binding to the promoter region from -370 to +65 was studied using DNase I footprinting and gel shift assays. Five protein binding sites were identified, which are recognized by nuclear proteins from either testis or liver. Site 1 from -64 to -48, contains part of a cAMP responsive element (CRE), which in testis is recognized by CREM tau, an activator of post-meiotic transcription. Testicular protein(s) also binds to three other promoter domains: site 2, -87 to -67, a region containing a CAAT box, and sites 4 and 5, -239 to -210 and -328 to -311, sequences with similarity to consensus steroid hormone responsive elements (HRE). In contrast, interactions between the mP2 promoter and nuclear factors from liver, a tissue in which the mP2 gene is not transcribed, are observed at sites 1, 2, and 4, as well as at an additional region at site 3, -202 to -175. Because occupancy at site 3 appears to correlate with inactivation of the gene in non-testicular tissues, whereas testicular protein binding at site 5 appears to be associated with active transcription, we conclude that the mP2 promoter displays intricate tissue-specific patterns of protein/DNA interactions at key regulatory elements.
Linking Community and Classroom in Higher Education: Service-Learning and Student Empowerment

ABSTRACT In this article, service learning is viewed as a means to better prepare students for the realities of work life. Service learning is a way in which abstract concepts can be applied in a real world setting to improve student learning.
Foreign exchange market intervention in interdependent economies: A case for capricious policy?

Abstract In discussions of the appropriate design of monetary policy, it has generally been agreed that some kind of rule (with or without feedback from economic data) is preferable to a randomized policy. In this paper, this proposition is reexamined in a two-country model in which the monetary policy rule chosen in each country affects the variability of income and prices in the other country. It is shown that, by pursuing a randomized policy, the monetary authorities may actually be able to reduce the variability of national income in their own country—but only at the expense of greater variability in the other country's income.
Cortical and retinal spectral sensitivity of the hooded rat

Abstract Using the b-wave of the electroretinogram (ERG) and the initial positive wave of the visually evoked cortical potential (VECP). spectral sensitivity curves were determined for the retina and visual cortex of the hooded rat. The results show that the retina is maximally sensitive in the region of 485–500nm under scotopic conditions with an increase in long-wave sensitivity under photopic conditions. The results for the cortex showed a maximum in the region of 485–500nm and an increased sensitivity in the long-wave region under both photopic and scotopic conditions. These findings and the anatomical' evidence for cones provide further support for the existence of at least 2 types of receptors in the rat retina.
Living in stools is not as dumb as you think.

It has been difficult to know what might provide the best commentary for this series of articles commemorating the 100-year anniversary of the American Society for Microbiology (ASM). I have been an active medical bacteriologist for the past 46 years (or at least an ASM member for that time). Not unexpectedly, I think the most extraordinary advances in the last 100 years have taken place in understanding how bacteria cause infection and disease. I have worked on understanding Salmonella for a good part of the time since 1952, which was the first time in my life that I actually grew this organism from a clinical sample taken from the stools of an infected infant. Thus, I will use Salmonella as the touchstone for the discussion that follows.
Crystal structure of the annexin XII hexamer and implications for bilayer insertion.

ANNEXINS are a family of calcium- and phospholipid-binding proteins 1,2 implicated in a number of biological processes including membrane fusion 3 and ion channel formation 4-7 . The crystal structure of the annexin XII hexamer, refined at 2.8 A resolution, forms a concave disk with 3-2 symmetry, about 100 A in diameter and 70 A thick with a central hydrophilic pore. Six intermolecular Ca 2+ ions are involved in hexamer formation. An additional 18 Ca 2+ ions are located on the perimeter of the disk, accessible only from the side of the hexameric disk. On the basis of the hexamer structure we propose here a new mode of protein-phospholipid bilayer interaction that is distinct from the hydrophobic insertion of typical membrane proteins. This speculative model postulates the Ca 2+ -dependent insertion of the hydrophilic annexin XII hexamer into phospholipid bilayers with local reorientation of the bilayer phospholipids.
Engineering proteins with enhanced mechanical stability by force-specific sequence motifs.

Use of atomic force microscopy (AFM) has recently led to a better understanding of the molecular mechanisms of the unfolding process by mechanical forces; however, the rational design of novel proteins with specific mechanical strength remains challenging. We have approached this problem from a new perspective that generates linear physical-chemical properties (PCP) motifs from a limited AFM data set. Guided by our linear sequence analysis we designed and analyzed four new mutants of the titin I1 domain with the goal of increasing the domain's mechanical strength. All four mutants could be cloned and expressed as soluble proteins. AFM data indicate that at least two of the mutants have increased molecular mechanical strength. This observation suggests that the PCP method is useful to graft sequences specific for high mechanical stability to weak proteins to increase their mechanical stability, and represents an additional tool in the design of novel proteins besides steered molecular dynamics calculations, coarse grained simulations and phi-value analysis of the transition state.
Thermal relaxation of charm in hadronic matter

Abstract The thermal relaxation rate of open-charm ( D ) mesons in hot and dense hadronic matter is calculated using empirical elastic scattering amplitudes. D -meson interactions with thermal pions are approximated by D ⁎ resonances, while scattering off other hadrons ( K , η , ρ , ω , K ⁎ , N , Δ) is evaluated using vacuum scattering amplitudes as available in the literature based on effective Lagrangians and constrained by realistic spectroscopy. The thermal relaxation time of D -mesons in a hot π gas is found to be around 25–50 fm/ c for temperatures T = 150 – 180 MeV , which reduces to 10–25 fm/ c in a hadron-resonance gas. The latter values, argued to be conservative estimates, imply significant modifications of D -meson spectra in heavy-ion collisions. Close to the critical temperature ( T c ), the spatial diffusion coefficient ( D s ) is surprisingly similar to recent calculations for charm quarks in the Quark–Gluon Plasma using non-perturbative T -matrix interactions. This suggests a possibly continuous minimum structure of D s around T c .
Binocularity in the cat visual cortex is reduced by sectioning the corpus callosum

In the normal cat, most cells in area 17 can be binocularly driven. Sectioning the corpus callosum results in a significant reduction in binocularly driven cells. Normal binocular vision is thus dependent on the corpus callosum.
Increase in Serum Ca2+/Mg2+ Ratio Promotes Proliferation of Prostate Cancer Cells by Activating TRPM7 Channels

TRPM7 is a novel magnesium-nucleotide-regulated metal current (MagNuM) channel that is regulated by serum Mg2+ concentrations. Changes in Mg2+ concentration have been shown to alter cell proliferation in various cells; however, the mechanism and the ion channel(s) involved have not yet been identified. Here we demonstrate that TRPM7 is expressed in control and prostate cancer cells. Supplementation of intracellular Mg-ATP or addition of external 2-aminoethoxydiphenyl borate inhibited MagNuM currents. Furthermore, silencing of TRPM7 inhibited whereas overexpression of TRPM7 increased endogenous MagNuM currents, suggesting that these currents are dependent on TRPM7. Importantly, although an increase in the serum Ca2+/Mg2+ ratio facilitated Ca2+ influx in both control and prostate cancer cells, a significantly higher Ca2+ influx was observed in prostate cancer cells. TRPM7 expression was also increased in cancer cells, but its expression was not dependent on the Ca2+/Mg2+ ratio per se. Additionally, an increase in the extracellular Ca2+/Mg2+ ratio led to a significant increase in cell proliferation of prostate cancer cells when compared with control cells. Consistent with these results, age-matched prostate cancer patients also showed a subsequent increase in the Ca2+/Mg2+ ratio and TRPM7 expression. Altogether, we provide evidence that the TRPM7 channel has an important role in prostate cancer and have identified that the Ca2+/Mg2+ ratio could be essential for the initiation/progression of prostate cancer.
The determination of successive principal components without computation of tables of residual correlation coefficients

A procedure is presented for determining the successive principal components of a correlation matrix where it is not necessary to compute the successive tables of residual correlations. The original correlation matrix is bordered with a new row and column for each principal component that is determined.
Daily otolith increments and recruitment in two coral-reef wrasses, Thalassoma bifasciatum and Halichoeres bivittatus

Increments on the otoliths of two common coral reef fishes, the bluehead wrasse Thalassoma bifasciatum and the slippery dick Halichoeres bivittatus, were demonstrated by mark-recapture experiments to be daily. Otoliths were marked in two ways; by depriving fish of light, food, and temperature cycles and also by supplemental feeding in the field. Both experiments were performed in late 1980 in the San Blas Islands of Panama. A mark corresponding to settlement of the planktonic larva onto the reef was found on the otoliths of the bluehead wrasse. This settlement mark was used to calculate the dates of settlement of a collection of juveniles of this species taken from a patch reef in the San Blas Islands of Panama in 1981. Settlement occurred in short and irregular bursts. The number of daily increments before the settlement mark indicates a planktonic larval life of 40 to 72 d.
Exploratory activity and fear conditioning abnormalities develop early in R6/2 Huntington's disease transgenic mice.

The Huntington's disease R6/2 transgenic mouse model, containing exon 1 of the human huntingtin gene with a greatly increased CAG repeat length, shows multiple effects of the altered polyglutamine in the resultant protein. The authors report that exploratory and fear conditioning behavioral changes appear well before the onset of obvious pathology. The first differences in exploratory and fear conditioning behavior emerge by 4 and 5 weeks of age, respectively. These behaviors correlate with the earliest neurochemical and molecular changes previously reported and provide insight into functional mechanisms by which cellular and subcellular disease changes may mediate neurological symptoms. These studies provide behavioral protocols suitable for high-throughput screening of therapeutic agents.
Recovery of mating behavior in the female rat following VMH lesions.

Abstract On the day of proestrus, female rats were given large electrolytic lesions aimed at the ventromedial nucleus of the hypothalamus (VMH). Following a postoperative period of extended diestrus the vaginal smears showed irregular periods of vaginal cornification with a tendency toward prolonged periods of cornified smears. Sexual receptivity, measured in terms of the lordosis-to-mount ratio ( L% = L M × 100 ) was low on the evening of the first postsurgical proestrus, but improved markedly in subsequent mating sessions. Although the lordosis response was present, the intromission frequency remained below that observed during mating sessions with control females. Findings at autopsy together with the prolonged periods of vaginal cornification suggest that VMH lesions result in blocked or delayed ovulation. The behavioral data contradict previous reports of blocked mating behavior in VMH females based upon indirect measures of receptivity, i.e., the presence of vaginal plugs or sperm on the morning following overnight caging with sexually active males.
Characterization and in vitro bioavailability of β-carotene: Effects of microencapsulation method and food matrix

Abstract The objectives of this study were to determine the effect of microencapsulation method on physical properties and in vitro release and bioavailability of three types of β-carotene: a spray-dried powder of β-carotene and maltodextrin, commercially available water-dispersible β-carotene powder, and chitosan-coated β-carotene alginate. In vitro digestion trials were conducted with and without food matrices (yogurt, pudding) to elucidate the effect of food matrix on in vitro release and bioavailability. Microencapsulation method significantly affected (p
Pkc1p modifies CPY* degradation in the ERAD pathway

The process of endoplasmic reticulum-associated degradation (ERAD) involved in the degradation of misfolded N-linked glycoproteins utilizes Cdc48p which extracts misfolded glycoproteins from the lumen to the cytosol to present them for deglycosylation and degradation. Pkc1p has been identified as a component of the ERAD pathway, because deletion of the pkc1 gene impairs ERAD and causes accumulation of CPY* in the lumen of the ER, most probably because of the mislocalization of Cdc48p. In addition, we show that Cdc48p interacts in the cytosol with the deglycosylation enzyme, PNGase, only when Cdc48p is associated with a misfolded glycoprotein.
Differences in electrophysiological substrate in patients with coronary artery disease and cardiac arrest or ventricular tachycardia. Insights from endocardial mapping and signal-averaged electrocardiography.

BACKGROUNDMany studies have combined patients with hemodynamically well-tolerated ventricular tachycardia (VT) and those with cardiac arrest (CA) as a single, homogenous group. Recent studies suggest that these two groups have different electrophysiological substrates and responses to therapy. Most of these studies, however, enrolled patients with a variety of cardiac diagnoses.METHODS AND RESULTSWe used signal-averaged electrocardiography (SAECG) and endocardial catheter mapping to define the electrophysiological substrate in patients with coronary artery disease and VT or CA and correlate the results of the two methods. We also examined the usefulness of SAECG in CA patients to differentiate those with inducible arrhythmias from those who are noninducible. VT patients were more likely to have had a prior myocardial infarction (p = 0.0005) and to have inducible arrhythmias (p = 0.0001) than were CA patients. The induced arrhythmias in patients who presented with VT was VT in more than 90% of cases, where...
Evaluating document clustering for interactive information retrieval

We consider the problem of organizing and browsing the top ranked portion of the documents returned by an information retrieval system. We study the effectiveness of a document organization in helping a user to locate the relevant material among the retrieved documents as quickly as possible. In this context we examine a set of clustering algorithms and experimentally show that a clustering of the retrieved documents can be significantly more effective than traditional ranked list approach. We also show that the clustering approach can be as effective as the interactive relevance feedback based on query expansion while retaining an important advantage -- it provides the user with a valuable sense of control over the feedback process.
Improving Efficiency of Sugarcane Genotype Selection in Florida

The Canal Point (CP) sugarcane (Saccharum spp.) breeding program has developed highyielding cultivars for the organic soils of South Florida, but cultivar development has not been as successful for sand soils in this region. Our objectives were to improve fi nal-stage (Stage 4) selection effi ciency of this program by assessing interactions among genotypes, soils, and locations and other sources of variation and by comparing the relationship between repeatability and number of replications as a measure of precision for testing sugarcane genotypes on sand and muck soils. Sources of variation were partitioned for plant-cane, fi rst-ratoon, and second-ratoon data, from 7 yr and fi ve CP series in Stage 4 tested at eight locations on muck soils and two locations on sand soils. Variation related to genotype × location (soil) was highly signifi cant for cane and sugar yields for all series and crops, but most genotype × soil interactions were nonsignifi cant. This suggested that planting more Stage-4 tests on sand may improve genotype selection for these soils. The six replications used routinely in Stage 4 provided elevated levels of precision for both soil types. All locations with muck and sand soils in Stage 4 have ample testing resources for discriminating among genotypes. Our results indicate that, to improve sugarcane genotype selection for sand soils, increasing the number of sand locations would be a more successful strategy than increasing replications within locations. USDA-ARS, Sugarcane Field Station, 12990 US Hwy. 441 N., Canal Point, FL 33438. Received 23 Sept. 2009. *Corresponding author (ali
Effect of broad properties fuel on injector performance in a reverse flow combustor

The effect of fuel type on the performance of various fuel injectors was investigated in a reverse flow combustor. Combustor performance and emissions are documented for simplex pressure atomizing, spill flow, and airblast fuel injectors using a broad properties fuel and compared with performance using Jet A fuel. Test conditions simulated a range of flight conditions including sea level take off, low and high altitude cruise, as well as a parametric evaluation of the effect of increased combustor loading. The baseline simplex injector produced higher emission levels with corresponding lower combustion efficiency with the broad properties fuel. There was little or not loss in performance by the two advanced concept injectors with the broad properties fuel. The airblast injector proved to be especially insensitive to fuel type.
Continued-fraction decomposition of linear systems in the state space

Abstract Various results pertaining to a continued-fraction decomposition of matrix formal power series, and in particular of multi-input multi-output linear constant systems, are presented from a state-space point of view.
Carbon losses in soils previously exposed to elevated atmospheric CO2 in a chaparral ecosystem: Potential implications for a sustained biospheric C sink

Abstract Between 1996 and 2001 an experimental set up in a chaparral community near San Diego, CA, examined various plant and ecosystem responses to CO 2 concentrations ranging from 250 to 750 μl l − 1 . These experiments indicated a significant increase in soil C sequestration as CO 2 rose above the ambient levels. In 2003, two years after the cessation of the CO 2 treatments, we returned to this site to examine soil C dynamics with a particular emphasis on stability of specific pools of C. We found that in as little as two years, C content in the surface soils (0–15 cm) of previously CO 2 enriched plots had dropped to levels below those of the ambient and pretreatment soils. In contrast, C retained in response to CO 2 enrichment was more durable in the deeper soil layers (> 25 cm deep) where both organic and inorganic C were on average 26% and 55% greater, respectively, than C content of ambient plots. Using stable isotope tracers, we found that treatment C represented 25% of total soil C and contributed to 55% of soil CO 2 efflux, suggesting that most of treatment C is readily accessible to decomposers. We also found that, C present before CO 2 fumigation was decomposed at a faster rate in the plots that were exposed to elevated CO 2 than in those exposed to ambient CO 2 levels. To our knowledge, this is the first report that allows for a detail accounting of soil C after ceasing CO 2 treatments. Our study provides a unique insight to how stable the accrued soil C is as CO 2 increases in the atmosphere.