cssi/SciSciGPT-SciSciNet huggingface dataset:
Snakes assisted food image segmentation

In this paper we describe an image segmentation method for segmenting food items in images used for dietary assessment. Dietary assessment methods used to determine the foods and beverages consumed at a meal are essential for understanding the link between diet and health. Snakes, or active contours, are used extensively to locate object boundaries and segment images. Experimental results using classical snakes on food images show the problems associated with contour initialization and poor detection performance for food images. In this paper, we explore various methods of contour initialization and integrate a background removal method to improve the performance of food image segmentation. We describe the details of the proposed food image segmentation method and also evaluate our segmentation approach on food images.
Short Hairpin RNA-mediated Silencing of PRC (PGC-1-related Coactivator) Results in a Severe Respiratory Chain Deficiency Associated with the Proliferation of Aberrant Mitochondria

PRC, a member of the PGC-1 coactivator family, is responsive to serum growth factors and up-regulated in proliferating cells. Here, we investigated its in vivo role by stably silencing PRC expression with two different short hairpin RNAs (shRNA1 and shRNA4) that were lentivirally introduced into U2OS cells. shRNA1 transductants exhibited nearly complete knockdown of PRC protein, whereas shRNA4 transductants expressed PRC protein at ∼15% of the control level. Complete PRC silencing by shRNA1 resulted in a severe inhibition of respiratory growth; reduced expression of respiratory protein subunits from complexes I, II, III, and IV; markedly lower complex I and IV respiratory enzyme levels; and diminished mitochondrial ATP production. Surprisingly, shRNA1 transductants exhibited a striking proliferation of abnormal mitochondria that were devoid of organized cristae and displayed severe membrane abnormalities. Although shRNA4 transductants had normal respiratory subunit expression and a moderately diminished respiratory growth rate, both transductants showed markedly reduced growth on glucose accompanied by inhibition of G1/S cell cycle progression. Microarray analysis revealed striking overlaps in the genes affected by PRC silencing in the two transductants, and the functional identities of these overlapping genes were consistent with the observed mitochondrial and cell growth phenotypes. The consistency between phenotype and PRC expression levels in the two independent transductant lines argues that the defects result from PRC silencing and not from off target effects. These results support a role for PRC in the integration of pathways directing mitochondrial respiratory function and cell growth.
Horizontal variability and boundary-layer modeling

Micrometeorologists have traditionally set aside consideration of horizontal variability and have studied boundary-layer structure with horizontal homogeneity. The numerical forecasting of boundary-layer structures, over normally varying terrain and including normal disturbances such as fronts, requires selection of an ‘appropriate’ horizontal scale.
A Follow-Up Note on Graduate Training in the Teaching of Introductory Psychology

This note extends a previous report (Rickard, Prentice-Dunn, Rogers, Scogin, & Lyman, 1991) on a graduate course in the teaching of introductoy psychology. Students who had completed the supervised-teaching experience performed better on a test of psychology content than did comparable students who had not. Data supported the informal observations of faculty, doctoral students, and PhD graduates about the value of teh supervised-teaching experience.
A Comparsion of Figure Drawings and WISC IQ's Among Disabled Readers

Children's figure drawings have been used as a measure of intellectual development since at least the 1920's. This study assesses the relationship between IQ scores from two systems for scoring figure drawings as compared to performance on the WISC in a population of disabled readers. The two figure drawing scoring systems yield very similar results in spite of the fact that one was more recently standardized and is more complex. Scores derived from figure drawings show significant correlations with scores from the Performance, but not the Verbal, section of the WISC. Scores on several of the Performance subtests were also significantly related to figure drawing scores. The results of the study also pointed out the need to differentiate subgroups among disabled readers.
How to inspire value-laden collaborative consumer-generated content

Abstract Marketing is evolving into true participatory conversations. Once-tidy, controlled marketing communications with distinct, identifiable corporate spokespeople are giving way to a messy tangle of market-based communications consisting of multiple authors including customers, competitors, observers, employees, and interested collectives. Amidst this, we find consumer-generated content (CGC) that is predominantly antithetical to previous studies, which assumed CGC to be inspired by personal brand attachment and/or the desire to see discrete-authored CGC disseminated, or even motivated by monetary reward. Authorship of collaboratively-produced CGC is virtually untraceable, unknown, and monetarily uncompensated. The true reward is the process, and the outcome is not reliant on technical prowess but rather semiotic manipulation, narrative manipulation, and complex brand character development. Consumers—especially those who are members of active consumer collectives—are skillful, proficient, and prolific in the creation of CGC, with high resonance among very engaged consumers. We advocate harnessing collaborative CGC efforts toward long-term marketing objectives, and offer a brief tutorial.
Rectovaginal constriction in Jersey cattle. VII. Anatomical characterization of the constriction rings in the anal and vestibular canals.

Summary The constricting bands in Jersey cows affected with rectovaginal constriction (RVC) were studied by placing ligatures around them prior to euthanasia or slaughter of the animals, so that their exact location and composition could be determined and compared to the anal canals of normal animals. Subsequent studies revealed that the constricting rings are comprised of normal layers of these canals that are modified so that they are exaggerated. Thus, there are no novel anatomical structures present only in RVC-affected individuals that could represent vestiges of an earlier stage of development, for example. Zusammenfassung Rectovaginale Konstriktion bei Jersey-Rindern VII. Anatomische Charakterisierung des Konstriktionsrings im Anal- und Vestibularkanal Bei Jersey-Kuhen mit rectovaginaler Konstriktion (RVC) wurden die Konstriktionszonen durch Ligaturen, die vor der Totung der Tiere gesetzt wurden, untersucht. Damit konnte die genaue Lokalisation sowie die Zusammensetzung der Konstriktionszonen bestimmt werden. Die Untersuchungen erbrachten, das die Konstriktionsringe von normalen Schichten des Analkanals gebildet werden, die gegenuber den normalen Verhaltnissen lediglich verstarkt sind. Damit sind bei RVC-Tieren keine besonderen anatomischen Strukturen vorhanden, wie sie z.B. als Uberbleibsel fruherer Entwicklungsstadien vorstellbar waren.
The effects of environment and hydration on protein dynamics: A simulation study of myoglobin

Abstract Three classes of molecular dynamics (MD) simulations of carboxy-myoglobin (MbCO) have been performed to investigate the environmental and temperature dependence of protein dynamics. The first class examines the effects of hydration. Simulations of MbCO were performed at 100 and 300 K with 0, 35, 100, 349, and 999 water molecules, and at 300 K with 3832 water molecules. The second class considers a cluster of three partially hydrated MbCO molecules (349 waters each) at 100, 180, 240, and 300 K. The third class of simulations, performed at 100 and 300 K, examines hydration by D2O and also the effects of different vacuum models and long-range electrostatic cutoff methods. The simulations generally consist of 200 ps of heating and equilibration followed by 100 ps of dynamics used for analysis. Atomic fluctuation is compared to neutron scattering data to better determine the type of calculation needed to reproduce the low-temperature behavior of proteins. The simulations of hydrated myoglobin indicate that as the hydration increases: (i) agreement with the X-ray structure improves, (ii) the number of heavy-atom dihedral transitions decreases at both 100 and 300 K, and (iii) atomic fluctuations decrease at 100 K but increase at 300 K. The cluster and deuterated simulations exhibit atomic fluctuations at 100 K similar to, but slightly reduced from, those of a single hydrated myoglobin. Thus, our previous observation from MD simulations of low-temperature mean-square fluctuation three times larger than that observed experimentally does not appear to be due to the mass of the water model, nor the complete absence of intermolecular protein-protein contacts.
Reflections on informed consent: 40 years after its birth.

Dr. Jay Katz a physician and law professor at Yale University invites fellow physicians to set aside their dislike of informed consent and consider both its origins and possible future in the field of medicine. He notes that informed consent with its initial pronouncements on patient roles in medical decision- making surfaced in 1957 in US Supreme Court case entitled Salgo vs. Leland Stanford Jr. University Board of Trustees. The notion was expanded by Natanson vs. Kline in 1960 and by Cantenbury vs. Spence in 1972. Informed consent was not designed to serve as a medical blueprint for interactions between physicians and patients says Katz but rather to push physicians to articulate medical standards of disclosure that would better conform to basic legal principles. However the medical profession did not do this and the task of fashioning a doctrine responsive to both the realities of medical practice and the requirements of law remains to be done. Thus Katz advocates a reexamination of the unitary scope of the informed-consent doctrine in light of the diversity of medical practices. He argues that: disclosures may have to be limited to the most essential parts; that the fullest disclosures should be enforced and shared decision making should be an absolute requirement for acute disorders; that the pace of disclosure may have to be slower for conditions in which the prognosis is dire and a fatal outcome is likely; and informed consent could be dispensed with if the patient agrees for relatively minor time-limited disorders.
Simulation of a Fifteen Passenger Van Rollover and Occupant Kinematics

This study examined the occupant kinematics during the rollover of a 15-passenger van. The main focus of the investigation was to determine possible kinematics that led to ejection, the time period of the potential ejections, and to determine injury causing kinematics or impacts. The time during which the ejections occurred was used to determine whether all the ejections could have occurred during the first overturn or if at least two overturns were necessary. The occupants were simulated in the estraint condition similar to the accident, all restrained in lap belts, and all restrained in lap/shoulder belts. The results of the simulation indicated that predicted injury levels were reduced and full ejection was eliminated when occupants were properly restrained with lap/shoulder belts. The simulation did not account for intrusion when determining injury.Copyright © 2003 by ASME
A new satellite RNA is associated with natural infections of cucumber mosaic virus in succulent snap bean

Cucumber mosaic virus (CMV) was consistently recovered from symptomatic snap bean plants during surveys conducted in 2007 and 2008 in central Wisconsin. A large proportion of these CMV-infected plants contained a single-stranded linear RNA molecule consisting of 339 nucleotides and sharing 90–94% sequence identity with other satellite (sat) RNAs of CMV. Comparison of this satRNA sequence with currently available CMV satRNA sequences suggests this to be a novel satRNA.
Importance of Teaching

I strongly agree with the National Science Foundation's (NSF's) education chief, Luther Williams, who is quoted by Jeffrey Mervis as stating that NSF alone cannot promote teaching at traditional research universities (News, [19 Apr., p. 345][1]). Until the culture of tenure and promotion at these
Prognostic factors in advanced stage squamous cell cancer of the cervix.

Background. This study was undertaken to review prognostic factors for advanced squamous cell cancer of the cervix. Methods. A clinicopathologic review of patients diagnosed with advanced stage squamous cell cancer of the cervix was performed at the University of Michigan Medical Center, Ann Arbor, Michigan, from 1970–1985. Results. All patients had squamous cell disease and were divided according to the following stages: Stage IIIa (4), Stage IIIb (113), Stage IVa (32), and Stage IVb (26). The cumulative 5-year survival was as follows: Stage IIIa (50%), Stage IIIb (37%), Stage IVa (14%), and Stage IVb (4%). Prognostic features for Stage IIIb disease showed that the intravenous pyelogram status significantly predicted cumulative 5-year survival (P = 0.00001). When the intravenous pyelogram was normal, 47% survived. When ureteral obstruction was present without renal failure, 29% survived, and when renal failure occurred, all patients were dead of disease by 16 months. The lymph node status significantly influenced cumulative 5-year survival (P = 0.004). When lymph nodes were negative, 47% survived. When three or fewer were positive, 44% survived. When more than three were positive, 11% survived. When pelvic lymph nodes were positive and paraaortic node status was determined, 25% survived when paraaortic lymph nodes were negative, while 8% survived when these were positive (P = 0.06). Factors that did not influence 5-year survival included one or both sidewall involvement (P = 0.77), tumor grade (P = 0.23), diabetes (P = 0.92), hypertension (P = 0.85), and obesity (P = 0.47). The diagnosis of Stage IVa disease was made by the presence of fistula at initial presentation (n = 8), cystoscopy (n = 21), and sigmoidoscopy (n = 1). One patient developed a treatment-related vesicovaginal fistula when bladder involvement was diagnosed by cystoscopy. Ah 18 patients who presented with renal failure (Stage IIIb, 9; Stage IVa, 9) were analyzed as a group, and only 1 patient survived. The median survival in 15 patients who underwent nephrostomy was 8 months, range 1–36 months. Ten of 15 patients (66%) were dead of disease within 1 year. Three patients refused renal bypass, and these three patients died at 1,2, and 3 months, respectively. Conclusions. Advanced stage disease represents a significant challenge, and when ureteral obstruction or renal failure is present, the prognosis is markedly decreased.
Should patients with anatomically narrow angles have prophylactic iridectomy

In this set of articles, the authors outline methods and criteria for determining which patients with anatomically narrow angles should have laser iridectomy to prevent acute angle-closure glaucoma.
Event history analysis of dengue fever epidemic and inter-epidemic spells in Barbados, Brazil, and Thailand.

Summary Objective This study investigated meteorological and demographic factors affecting the length of dengue fever epidemics and the length of time between epidemics in Barbados, Brazil, and Thailand. Methods Region-specific meteorological and demographic data were collected for 104 sites from public sources. Fixed effects piecewise logistic event history analysis was used to quantify the effects of time-varying covariates on the duration of inter-epidemic spells and for the duration of epidemics. Results Mean monthly temperature was the most important factor affecting the duration of both inter-epidemic spells ( β = 0.543; confidence interval (CI) 0.4954, 0.5906) and epidemic spells ( β = −0.648; CI −0.7553, −0.5405). Drought conditions increased the time between epidemics. Increased temperature hastened the onset of an epidemic, and during an epidemic, higher mean temperature increased the duration of the epidemic. Conclusions By using a duration analysis, this study offers a novel approach for investigating the dynamics of dengue fever epidemiology. Furthermore, these results offer new insights into prior findings of a correlation between temperature and the geographic range and vector efficiency of dengue fever.
Processing effects on the morphological stability at epitaxial interfaces

A phenomenological framework has been developed to account for interfacial instabilities during epitaxial growth. It is proposed that these instabilities are influenced by surface phenomena, through modification of surface free energy of the substrate by the first monolayers of the depositing element. Instabilities occuring in the CoSi2/Si system are considered as an example. Specifically, Gjostein’s (1963) treatment of surface instabilities caused by an adsorbing gas is applied here, and instability criteria are derived in terms of the Herring construction (Herring, 1951).
Emerging Evidence on the Role of Estrogenic Sorghum Flavonoids in Colon Cancer Prevention

Consumption of whole grains has been linked to reduced risk of colon cancer. The benefits of fiber and antioxidant minerals and vitamins found in whole grains are well recognized. The inherent estrogen-like activities of specific polyphenols contained in whole grains also play an important role in colon cancer prevention. Estrogen is believed to protect damaged colonocytes and prevent them from developing into malignancies. The protective effects of estrogen, such as induction of apoptosis and tumor-suppressing genes, are believed to be mediated via estrogen receptor-β, the predominant estrogen receptor (ER) in the colon. Emerging evidence on the role of specific flavonoids that are abundant in sorghum in ER-mediated colon cancer prevention are discussed. The overall implication of the evidence for the importance of whole grain consumption in colorectal cancer prevention is highlighted.
Pigmented basal cell carcinoma and superficial spreading malignant melanoma: an unusual combination*

We report pigmented lesions in 2 white male patients, which were clinically diagnosed as superficial spreading malignant melanoma and histologically showed combined features of superficial spreading malignant melanoma in situ and pigmented basal cell carcinoma. The significance of this association is not known but is most likely very rare.
Aqueous Phosphoester Bond Cleavage of Dimethyl Phosphate by Cp2MoCl2: First Reported Case of Hydrolytic Cleavage on an Unactivated Phosphate Diester by an Organometallic Complex

The organometallic compound bis(η5-cyclopentadienyl) molybdenum(IV) dichloride (Cp2MoCl2, Cp = η5-C5H5) promotes the phosphotester bond cleavage of dimethyl phosphate with rate accelerations of 104 at pH 4.0. NMR spectral evidence suggests this phosphoester bond cleavage proceeds through a hydrolytic pathway where the aquated Cp2MoCl2 binds to the phosphate diester and then carries out an intramolecular attack with either a Cp2Mo-bound water or hydroxide. This is the first reported case of an organometallic complex that hydrolyzes an unactivated phosphate diester.
Messergebnisse über die Dicke der Magenfundusschleimhaut im bioptischen Material

Bei 351 Fallen wurden Dickenmessungen der Magenfundusschleimhaut im Saugprobeexcisionsmaterial vorgenommen. 1. Die Mesergebnisse zeigen eine, durch die histologische Aufarbeitung bedingte Variabilitat von rund 5%. In Abhangigkeit von der morphologischen Struktur wurden folgende Mittelwerte erhoben: normale Schleimhaut 0,72 mm; noch normale Mucosa 0,758 mm; masige Oberflachenentzundung 0,716 mm; ausgepragte Oberflachenentzundung 0,717 mm; beginnende Atrophie 0,650 mm; atrophische Gastritis 0,591 mm. 2. Die vergleichende Messung der Drusenschicht und des Stratum proprium zeigt, das bereits bei der Oberflachenenztundung eine Verschmalerung des Drusenparenchymes einsetzt. 3. Durch Dickenmessungen ist nur in wenigen Fallen eine Diagnosestellung moglich. 4. Die Ergebnisse liefern einen weiteren Beweis dafur, das sich die atrophische Gastritis uber die Stadien der Oberflachenentzundung entwickelt.
Interpenetrating polymer networks from triglyceride oils containing special functional groups: A brief review1

Although most triglyceride oils contain only double bond functionality, a few oils such as castor oil, vernonia oil, lesquerella oil, etc., contain other functional groups. These functional groups include hydroxy and epoxy groups, permitting the easy formation of polyesters and/or polyurethanes. In addition to the natural formation of epoxy-bearing oils, the double bond functionality in ordinary triglyceride oils can be epoxidized. When these oils are polymerized to form polyesters or polyurethanes in the presence of polystyrene to synthesize interpenetrating polymer networks (IPN), a new class of tough plastics is formed.
CO Binding to the FeMo Cofactor of CO-Inhibited Nitrogenase: 13CO and 1H Q-Band ENDOR Investigation

The resting state of nitrogenase shows an S = 3/2 electron paramagnetic resonance (EPR) signal resulting from the FeMo-cofactor (MoFe7S9:homocitrate) of the MoFe protein. When the enzyme undergoes turnover under a CO atmosphere, this signal disappears and two new ones appear: one under low pressure of CO (denoted lo-CO; 0.08 atm) and the other under high pressure of CO (denoted hi-CO; 0.5 atm). Our recent Q-band (35 GHz) 13C and 57Fe electron nuclear double resonance (ENDOR) studies demonstrated that one CO is bound to the FeMo-cofactor of lo-CO and two to the cofactor of hi-CO. [Christie, P. D.; Lee, H. I.; Cameron, L. M.; Hales, B. J.; Orme-Johnson, W. H.; Hoffman, B. M. J. Am. Chem. Soc. 1996, 118, 8707−8709. Pollack, R. C.; Lee, H. I.; Cameron, L. M.; DeRose, V. J.; Hales, B. J.; Orme-Johnson, W. H.; Hoffman, B. M. J. Am. Chem. Soc. 1995, 117, 8686−8687.] In the present report, we examine the CO-bound FeMo-cofactor in both the lo- and hi-CO forms of the MoFe protein from Azotobacter vinelandii by com...
CAN THE CARBONIZING DRAGON BE DOMESTICATED? INSIGHTS FROM A DECOMPOSITION OF ENERGY CONSUMPTION AND INTENSITY IN CHINA, 1987–2007

China has relied on energy to stimulate its booming economy. As a result, its share of world energy consumption rose to 17.3% in 2009 from 7.9% in 1978. Somewhat surprisingly, through 2000 its rate of energy consumption was about half its rate of economic growth. This trend changed after 2001 as energy consumption rose about 1.3 times more rapidly than did gross domestic product through 2005. Through heavy governmental influence, energy intensity subsequently reduced through 2007, but just marginally. This paper uses the structural decomposition approach to understand key drivers behind changes in China's energy intensity and its energy consumption from 1987 to 2007. In our model, energy intensity change was decomposed into five factors: changes in energy efficiency, changes in share of value added, changes in input structure, changes in consumption structure, and changes in consumption volume. This paper provides insights into how changes in China's economic structure, technology, urbanization, and lifes...
Perceived benefits of a transplant surgery experience to general surgery residency training.

Objectives The benefit of a solid-organ transplant experience during general surgical training has been questioned recently. In 2008, in response to an American Board of Surgery (ABS) directive, a survey was conducted by the Association of Program Directors in Surgery (APDS) in coordination with the American Society of Transplant Surgeons (ASTS) to determine the perceived value of a transplant surgery rotation to program directors and residents. With the aim of providing additional insight, we conducted a separate study, independent of the ABS and ASTS, to ascertain resident perceptions regarding the specific skill sets that they acquire during their transplant surgery rotations and their applicability to other surgical subspecialties. Methods A preliminary, 51-item, web-based questionnaire was completed by 69.6% of residents in nationally accredited general surgery programs who accessed the survey. The results were examined using appropriate statistical methods to determine associations between answers. Results Although only 16.6% of participants responded that they were considering a career in transplantation, 63.4% answered that the skill sets acquired during this rotation would assist them in their surgical careers regardless of their chosen specialty. Most (65.5%) respondents answered that the techniques learned were directly applicable to other specialties, such as vascular, urologic, trauma, and hepatobiliary surgery. Free response questions indicated that the most common criticisms of this rotation were the limited amount of operative participation, lack of teaching by attendings, and lifestyle limitations. Conclusions The results of this study indicate that surgery residents are conflicted regarding their transplant surgery experience but regard it as a beneficial addition to their training. Most respondents indicated also that these skills were transferable directly to other surgical specialties.
Light Activated Recombination

Many genes elicit their actions through their expression in precise spatial patterns in tissues. Photoregulated expression systems offer a means to remotely pattern gene expression in tissues. Using currently available photopatterning methods, gene expression is only transient. Herein is described a general method to permanently alter a cell's genome under the control of light. The photocaged estrogen receptor (ER) antagonists, nitroveratryl−hydroxytamoxifen (Nv-HTam) and nitroveratryl−hydroxytamoxifen aziridine (Nv-HTaz), mediate exposure-dependent recombination in cells expressing the Cre−ER, a fusion of the site-specific recombinase Cre and ER. Both Nv-HTam and Nv-HTaz only activate recombination by Cre−ER after exposure to light. When released only intracellularly, the covalent-modifying Taz can mediate significant amounts of recombination in an exposure-dependent manner. Nv-HTaz and Cre−ER represent perhaps the first compound that can be used to photopattern gene expression through recombination.
Postnatal lead exposure alters expression of forebrain p75 and TrkA nerve growth factor receptors

Abstract Lead is a potent developmental neurotoxicant that affects many aspects of cognition and behavior. The hippocampus and striatum are among the areas particularly sensitive to the effects of lead and cholinergic neurons in both regions depend upon nerve growth factor (NGF) for their survival and maturation. The present study examined the extent to which postnatal lead exposure may affect the survival and expression of neuroptrophin receptors of septo-hippocampal cholinergic projection neurons in the medial septum/vertical limb of the diagonal band of Broca (MS/VDB) and cholinergic neurons of the striatum. Weanling rats were fed chow containing lead acetate for 30 days and effects on cholinergic cell number and the number of cells expressing neurotrophin receptors p75 NGFR and trkA were assessed. A decrease in the number of cells expressing p75 NGFR and an increase in the number of cells expressing trkA receptor was observed in the MS/VDB of lead-exposed rats, without a loss of cholinergic cell number or alteration in cell size. Lead-exposure resulted in a significant decrease in trkA-expressing cells in the striatum but no change in the number or size of cholinergic neurons. These results suggest that a brief postnatal lead exposure does not result in loss of MS/VDB or striatal cholinergic neurons but does modify the expression of neurotrophin receptors in these regions. The significance of these effects on the septo-hippocampal and striatal functioning remains to be studied.
The surface band structure of W(112)

Both the experimental and theoretical band structure of the W(112) surface are presented, with the theoretical band structure calculated by the film–LAPW (linearized augmented plane waves) method. The results permit one to compare the W(112) and Mo(112) band structures and illuminate the similarities. It is found that for the W(112) surface the main photoemission features combine contributions from both the surface and bulk, as has been previously noted for Mo(112). The main differences between the electronic structures of the furrowed W(112) and Mo(112) surfaces are seen in the width of occupied bands. The differences are attributed to the extent of localization of valence 4d and 5s electrons in Mo and 5d and 6s electrons in W. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
A Short Asymmetric Route to the Bromophycolide A and D Skeleton

An asymmetric synthesis of the bromophycolide D ring system has been achieved in seven steps from a known geranylgeranylated benzoate, via bromonium-promoted transannular cyclization of a macrocyclic intermediate.
The Unique Kinetics of Iron Release from Transferrin: The Role of Receptor, Lobe–Lobe Interactions, and Salt at Endosomal pH

The transferrins are a family of bilobal iron-binding proteins that play the crucial role of binding ferric iron and keeping it in solution, thereby controlling the levels of this important metal. Human serum transferrin (hTF) carries one iron in each of two similar lobes. Understanding the detailed mechanism of iron release from each lobe of hTF during receptor mediated endocytosis has been extremely challenging because of the active participation of the transferrin receptor (TFR), salt, a chelator, lobe-lobe interactions and the low pH within the endosome. Our use of authentic monoferric hTF (unable to bind iron in one lobe) or of diferric hTF (with iron locked in one lobe), provided distinct kinetic end points allowing us to bypass many of the previous difficulties. The capture and unambiguous assignment of all kinetic events associated with iron release by stopped flow spectrofluorimetry, in the presence and absence of the TFR, unequivocally establishes the decisive role of the TFR in promoting efficient and balanced iron release from both lobes of hTF during one endocytic cycle. For the first time the four microscopic rate constants required to accurately describe the kinetics of iron removal are reported for hTF with and without the TFR. Specifically, at pH 5.6, the TFR enhances the rate of iron release from the C-lobe (7- to 11-fold), and slows the rate of iron release from the N-lobe (6- to 15-fold), making them more equivalent and producing an increase in the net rate of iron removal from Fe2hTF. Calculated cooperativity factors, in addition to plots of time dependent species distributions in the absence and presence of the TFR clearly illustrate the differences. Accurate rate constants for the pH and salt induced conformational changes in each lobe precisely delineate how delivery of iron within the physiologically relevant time frame of 2 min might be accomplished.
Regulation of dextran sodium sulfate induced colitis by leukocyte beta 2 integrins

Inflammatory bowel diseases (IBD) are chronic inflammatory disorders whose etiology remains unknown. Reports have shown that infiltration of leukocytes into intestinal tissue is a pathognomonic hallmark for this disease. Leukocyte beta(2) integrins are heterodimeric adhesion membrane proteins that are exclusively expressed on leukocytes and participate in immune cell adhesion and activation. In this study, we examined the pathophysiological role of the beta(2) integrins CD18, CD11a, and CD11b in the pathogenesis of dextran sodium sulfte (DSS)-induced experimental colitis. Disease activity was measured by daily assessment of clinical parameters including stool consistency, weight loss, occult blood, and gross rectal bleeding. Histopathological changes including severity of inflammation, surface epithelial/crypt damage, and depth of injury were also determined. The CD18 null and CD11a null mice had significantly lower disease activity and cumulative histopathological scores compared to wild-type mice. Interestingly, CD11b null mice did not show protection against DSS colitis and displayed increased disease activity compared to wild-type mice. Examination of specific leukocyte populations in the distal colon from various mice revealed significant attenuation of neutrophil and macrophage infiltrates in CD18, CD11a, and CD11b null mice. Surprisingly, the CD11b null mice showed a significant increase in plasma cell infiltration in response to DSS suggesting that this molecule may influence plasma cell function during colitis. This study demonstrates that genetic loss of CD18 or CD11a is protective during experimental colitis and that CD11b may serve a regulatory role during development of disease.
Experimental Research of Spouted Particulate Electrodes on Removal of Copper Wastewater

In this research, heavy metal copper was chosen for this study, with its sulfate solution simulated wastewater, using spouted particulate electrodes to purify wastewater and recycle metal copper. Experimental studied the effects on different conditions of electrodeposition, such as pH, constant current, copper ion concentration, the size of the cathode particle and nitrogen sparging. The results showed the optimum conditions were that pH was 3.0, constant current was 10.0A, the size of cathode particle was 1.8mm and with nitrogen sparging. In particular, nitrogen sparging not only reduced dissolved oxygen in wastewater to prevent the metal back to solution, but also handled the problem of low current efficiency due to concentration polarization and electrochemical polarization.
DO THIRD-GENERATION CEPHALOSPORINS HAVE A ROLE IN GRAM-NEGATIVE CNS INFECTIONS|[quest]|

The role of third-generation cephalosporins in pediatric gram-negative CNS infections remains undefined. Therefore, we reviewed our experience with these drugs in 42 patients (ages 19 days to 11 years) with ventriculitis complicating hydrocephalus (14), or meningitis (28), 30 treated with moxalactam and 12 with ceftriaxone. Moxalactam dosages were 50-100 mg/kg q 8 hrs for 10-29 days, and ceftriaxone 50 mg/kg q 12 hrs for 10-31 days. Etiologic agents included H. influenzae type b (25), E. coli (8), klebsiella (6), E. cloacae (2), and salmonella (1). Median minimal inhibitory concentrations of moxalactam and ceftriaxone respectively for hemophilus were 0.055 and 0.003 μg/ml, and for enteric bacilli were 0.45 and 0.12 μg/ml. Levels in CSF or ventricular fluid ranged from 18-60 μg/ml for moxalactam and from 8.9-13.7 μg/ml for ceftriaxone. The bacteriologic cure rate was 100%. Clinical cures were demonstrated in 41/42 patients, with one patient unevaluable. No significant clinical side effects were noted; one patient had transient eosinophilia. The only complications were 2 patients with oral candidiasis and one with entero-coccal ventricular superinfection. No bleeding problems or significant diarrhea were encountered. Because of the safety and efficacy of moxalactam and ceftriaxone in the treatment of both gram-negative enteric and hemophilus CNS infections in children, these agents may now represent the drugs of choice for such infections.
The effect of basic employment and regional factors on net migration: A study for Washington state

Relationships between net migration and basic employment, income, and regional urbanization are examined using 1960–70 census data for the state of Washington. Regression analysis indicates that changes in employment in agriculture, forestry, fishing and mining and in manufacturing have a direct effect on the rate of net migration. Change in median family income is also directly related to net migration but the effect is not as strong as that of employment. Location by region has a substantial impact on net population shifts with net inflows attributable to the urbanization which occurred in western Washington from 1960 to 1970. The employment, income, and regional effects are clarified by explicitly recognizing rapid growth in educational, governmental and retirement activity and recent large increases in basic employment which occurred in two small groups of counties. Overall, the results indicate that while the rate of net migration is responsive to changes in basic employment and family income, it is also important to recognize regional factors such as urbanization.
Nuclear protein synthesis in Vicia faba.

A technique for the rapid isolation of cytoplasmic-free preparations of Vicia faba nuclei has been developed. By using this process and autoradiography, differences in rate and pattern of nuclear incorporation of tritiated lysine, arginine, and tryptophan in the meristematic cells have been studied. Lysine is incorporated rapidly into the nucleus, and concentration is particularly evident in the nucleolus and perinucleolar chromatin. Arginine incorporation is somewhat retarded. Long exposures of autoradiographs are necessary to show tryptophan label. Lysine incorporation first becomes evident in the perinucleolar chromatin. The nucleoli become labeled, although the product accumulated is quite mobile and is readily washed out of the nucleoli in the presence of nonradioactive lysine. Chromatin label, on the other hand, may still be found at the end of 48 hr, although the amount of label is decreased. A comparison of nuclear preparations and root tip smears indicates that lysine utilization occurs in all stages of the cell cycle in varying degrees. After 15 min in radioactive lysine, 100 per cent of the interphase meristematic nuclei are labeled. Prophase nuclei show some label, generally in the chromatin associated with the disintegrating nucleolus. Later stages of mitosis also appear to have incorporated the label.
Initiation of propagating buckles from local pipeline damages

This work deals with the subject of initiation of a propagating buckle in an offshore pipeline. If the external pressure is high enough then a propagating buckle can be initiated by locally denting the pipe. Such a buckle will propagate at any pressure above the propagation pressure of the pipe. The pressure at which a local geometric imperfection transforms itself into a propagating buckle is known as the initiation pressure. This pressure depends on the geometric characteristics of the damage. The work restricts itself to a parametric study of damages produced by point, knife, and plate indentors. It is found that the geometry of these types of damages can be well represented by the ratio of minimum diameter:maximum diameter of the most damaged section. 18 references.
Infrared Magnetoelectroreflectance in Ge, GaSb, and InSb

An infrared electroreflectance technique has been used to observe magneto-optical effects associated with direct valence- to conduction-band transitions in Ge, GaSb, and InSb.
A Study on Flow Patterns and Pressure Drop in Adiabatic Two-Phase Flow Across a Bank of Micro Pin Fins

Flow patterns, void fraction and pressure drop in adiabatic nitrogen-water two phase flows across a bank of micro pin fin were experimentally investigated for Reynolds number ranging from 5 to 50. Staggered cylindrical shaped micro pin fins with diameter and height of 100 μm were micro-fabricated into 1 cm long, 1.8 mm microchannel. Flow patterns were determined by flow visualization and classified as bubbly-slug flow, gas-slug flow, bridged flow and annular flow. The applicability of conventional scale models to predict two-phase frictional pressure drop was also assessed. The two-phase frictional multiplier was found to be a strong function of mass flux and flow patterns unlike the previous results observed in the microchannel studies. It was observed that models from conventional scale systems did not adequately predict the two-phase frictional multiplier at micro-scale and thus, a modified model accounting for mass flux and flow patterns have been developed in this work.Copyright © 2007 by ASME
Phosphorylation of Ion channels

The introduction of highly specific reagents such as enzymes and inhibitors directly into living cells has proven to be a powerful tool in studying the modulation of cellular activity by protein phosphorylation. The use of exogenous kinases can be thought of as a pharmacological approach: this demonstrates that phosphorylation can produce modulation, but does not address the question of whether the cell actually uses this mechanism under normal physiological conditions. The complementary approach, the introduction of highly specific inhibitors such as R subunit or PKI, does ask whether endogenous kinase activity is necessary for a given physiological response. Together these two approaches have provided rather compelling evidence that cAMP-dependent and calcium/phospholipid-dependent protein phosphorylations can regulate membrane excitability. In several cases single-channel analysis has allowed the demonstration that an ion channel itself or something very close to the channel is the phosphorylation target, and it seems reasonable to assume that this will also be the case for many if not all of the other systems described above. Have any general principles emerged from the results to date? Certainly it seems clear that protein phosphorylation regulates not one but many classes of ion channels. As summarized in the Table, different channels can be modulated in different cells, some channels are activated while others are inhibited, and in some cells more than one channel is subject to modulation by phosphorylation. The list in the Table is probably not yet complete, and indeed it is not inconceivable that all ion channels can under appropriate conditions be regulated by phosphorylation. What aspect of channel function is altered by phosphorylation? The total membrane current, I, carried by a particular species of ion channel is given by Npi, where N is the number of active channels in the membrane, p is the probability that an individual channel will be open, and i is the single-channel current. In principle a change in I, the quantity measured in whole cell experiments, could be caused by a change in any one (or more) of the parameters, N, p or i (see Fig. 1). In the two cases in which single-channel measurements have allowed this question to be investigated, changes in N (Shuster et al., 1985) and p (Ewald et al., 1985) have been observed. Here again it seems unlikely that any one mechanism operates in all cases, and it would not be surprising to find that phosphorylation of some other channel results in a change in i.(ABSTRACT TRUNCATED AT 400 WORDS)
Prognostic models of thirty-day mortality and morbidity after major pulmonary resection.

Background:A part of the prospective, multi-institutional National Veterans Affairs Surgical Quality Improvement Program was developed to predict 30-day mortality and morbidity for patients undergoing a major pulmonary resection. Methods: Perioperative data were acquired from 194,319 noncardiac surgical operations at 123 Veterans Affairs Medical Centers between October 1, 1991, and August 31, 1995. Current Procedural Terminology code-based analysis was undertaken for major pulmonary resections (lobectomy and pneumonectomy). Preoperative, intraoperative, and outcome variables were collected. The 30-day mortality and morbidity models were developed by means of multivariable stepwise logistic regression with the preoperative and intraoperative variables used as independent predictors of outcome. Results: A total of 3516 patients (mean age 64 ± 9 years) underwent either lobectomy (n = 2949) or pneumonectomy (n = 567). Thirty-day mortality was 4.0% for lobectomy (119/2949) and 11.5% for pneumonectomy (65/567). The preoperative predictors of 30-day mortality were albumin, do not resuscitate status, transfusion of more than 4 units, age, disseminated cancer, impaired sensorium, prothrombin time more than 12 seconds, type of operation, and dyspnea. When the intraoperative variables were considered, intraoperative blood loss was added to the preoperative model. In the presence of these intraoperative variables in the model, do not resuscitate status and prothrombin time more than 12 seconds were only marginally significant. Thirty-day morbidity, defined as the presence of 1 or more of the 21 predefined complications, was 23.8% for lobectomy (703/2949) and 25.7% for pneumonectomy (146/567). In multivariable models, independent preoperative predictors (P < .05) of 30-day morbidity were age, weight loss greater than 10% in the 6 months before surgery, history of chronic obstructive pulmonary disease, transfusion of more than 4 units, albumin, hemiplegia, smoking, and dyspnea. When intraoperative variables were added to the preoperative model, the duration of operation time and intraoperative transfusions were included in the model and albumin became marginally significant. Conclusions: This analysis identifies independent patient risk factors that are associated with 30-day mortality and morbidity for patients undergoing a major pulmonary resection. This series provides an initial risk-adjustment model for major pulmonary resections. Future refinements will allow comparative assessment of surgical outcomes and quality of care at many institutions. (J Thorac Cardiovasc Surg 1999;117:969-79)
Inducibility of metallothionein biosynthesis in cultured normal and Menkes kinky hair disease fibroblasts: effects of copper and cadmium.

Summary: Metallothionein biosynthesis is not induced by extracellular copper in Menkes Kinky hair disease (MKHD) or in normal cultured fibroblasts under the conditions of these experiments. In the presence of copper, MKHD fibroblasts also incorporated less cysteine than did normal fibroblasts. Extracellular cadmium greatly enhanced the uptake of cysteine in both normal and MKHD cultures. By the technique of polyacrylamide gel electro-phoresis, it was demonstrated that metallothionein is induced by cadmium in normal and MKHD-cultured fibroblasts. Speculation: The abnormality in copper homeostasis of MKHD is not caused by an alteration of inducibility of metallothionein. Further investigation of the structure of metallothionein or other copper carrier proteins may uncover the etiology of MKHD.
Comparison for four methods for extracting periplasmic proteins

Abstract Overall, chloroform (CHL) extracts contained higher quantities of periplasmic proteins from three of seven bacteria than either cold osmotic shock (COS) or slow-and rapid-freeze/thaw (SF/T, RF/T) methods. CHL extracts contained equally higher levels for the six periplasmic enzymes tested. Considerably more protein was extracted by all four methods from two Pseudomonas spp. than from two Acinetobacter spp., and the RF/T method extracted considerably more from Acinetobacter than the other methods.
Study of the Förster resonance energy transfer in composite films of carbon nanotubes

We study excitonic energy transfer in a network of carbon nanotubes (CNTs), a promising light-absorbing material for next-generation organic solar cells. We calculate the exciton energy dispersion curves through solving the Bethe-Salpeter equation in the basis of tight-binding wave functions. Furthermore, we compute the Coulomb-coupling matrix element between bright excitonic states, in order to obtain the exciton transfer rate between similar and dissimilar carbon nanotubes with an arbitrary orientations. The conservation of momentum imposes a limitation on the energy transfer rate between parallel nanotubes of dierent chiralities. However, there is no such limitation for transfer between misoriented CNTs, which results in transfer rates of the same order of magnitude between carbon nanotubes of similar and dissimilar chiralities.