cssi/SciSciGPT-SciSciNet huggingface dataset:
Ultrastructure and role of the lobster vas deferens in spermatophore formation: The proximal segment

We have examined the anatomy of the vas deferens of the lobster Homarus americanus and have described the structure of the proximal vas deferens (segments one and two). The two tubes of segment one descend from the testes and gradually merge into segment two. The epithelium of segment one has synthetic activity and appears to contribute to the sperm-supporting matrix by exocytotic release of granules through its apical surface. The epithelium of segment two is also highly synthetic and secretes the primary spermatophore layer and part of the intermediate layer that surround the sperm mass. The trifoil shape of the extruded spermatophore is established through a change in height of some of the cells lining the lumen in segment two. Connective tissue and circular bands of striated muscle surround the epithelium of both segments.
Public-private partnerships and the future of digital access in US state archives

This project examines the network of public cultural institutions and private sector organizations engaged in the work of digitizing historical records. Recent technological advances, coupled with a changing financial climate for libraries and archives in the public sector, have resulted in a new generation of partnerships focused on the digitization of materials traditionally held in public institutions. Through a mixed-methods social science approach, this project seeks to understand how these partnerships form, how they are negotiated, managed, and how they end. It further examines how digitization through partnerships affects public access to records. This study is currently in progress; its results will provide a unique look into an emergent set of relationships and a public information access environment in transition.
Electrophysiology of differentiating mouse spermatozoa

The morphological aspects of spermatogenesis are well described in many mammalian species, but functional changes are not completely understood. Electrophysiological parameters were investigated in primary spermatocytes and early and late spermatids isolated from the seminiferous tubules of the mouse. Substantial changes were not detected in membrane potential between different developmental stages. Membrane potential was dependent on both potassium and sodium ion concentration gradients, but not on chloride gradients. The ratio of the permeabilities PNa/Pk varied according to the extracellular concentrations of sodium and potassium. Ouabain, a specific inhibitor of Na+, K+-activated ATPase, produced a maximal reduction in membrane potential of 20%. Comparisons were drawn between differentiating germ cells and previously determined properties of mature spermatozoa.
The Influence of a Strong Reducing Agent upon the Initiation of Callus from the Germinating Seedlings of Gossypium barbadense

Hard compact calluses were initiated from the cotyledons of germinating cotton seedlings (Gossypium barbadense L.) by use of a strong reducing agent (dithiothreitol) and a higher than normal concentration of an auxin, naphthalene-acetic acid. Dithiothreitol was superior to other compounds such as ascorbic acid and polyvinyl-pyrrolidone in preventing a toxic brown coloration of the initiated callus. After eight to ten subculturings, some of the hard callus tissues (c. 2 to 3%) proliferated into larger and faster growing cells.
AN APPROACH TO THE CHARACTERIZATION OF STEM CELLS IN MOUSE BONE MARROW.

The competence of bone marrow to promote recovery of hemopoietic function in irradiated recipient mice was observed to decrease on serial transplantation. Evidence is presented that the protective ability of the serially transplanted marrow can be reconstituted by addition of lymphoid cells harvested from normal lymph nodes. The nature and cellular basis of variations in the proliferative capacity of a given marrow cell population in the course of syngeneic (isologous) transplantation were investigated. A quantitative measure of this capacity of the marrow was obtained by determining the ability of the marrow to form colonies in the spleens of irradiated recipient mice and by measuring incorporation of I/sup 131/-labeled iododeoxyuridine, a specific desoxyribonucleic acid precursor, in such spleens. The proliferative capacity, as evaluated by these techniques, was related to the cellular constitution of the marrow, as determined by differential cytologic analysis of marrow smears, in an attempt to identify the responsible stem cells. (auth)
Octets, triplets and the top quark mass

Abstract We discuss N = 1 locally supersymmetric grand unified theories in which both the gauge group and supersymmetry are spontaneously broken in the same sector. It is proven that all such theories naturally contain light SU(3)C octet, SU(2)L triplet, and U(1)Y singlet chiral superfields in the low energy lagrangian. We show that these superfields lower the prediction of the top quark mass by at least 20 GeV, facilitating agreement with the experimental data.
HIV, HBV, and HCV Infections Among Drug-Involved, Inner-City, Street Sex Workers in Miami, Florida

This study describes the rates of HIV, HBV, and HCV seropositivity among drug-involved, female street sex workers in low-income, inner-city sections of Miami, Florida; further, their sociodemographic characteristics, drug use, and sexual risk behaviors were assessed; and predictors of infection were reported. A sample of 586 sex workers was recruited through targeted sampling methods, interviewed, and counseled and tested for the presence of antibody to HIV, HBV, and HCV. Respondents’ median age was 38 years, median time in sex work was 14 years, all were heavily involved in the use of alcohol and drugs, and 42% were homeless. More than half (51.0%) had engaged in unprotected vaginal sex in the past month. Prevalences were HIV, 22.4%; HBV, 53.4%; HCV, 29.7%. A multidimensional public health program must address not only issues related to unsafe sex, but also the problems of drug abuse, homelessness, and other lifestyle factors that contribute to risk behaviors.
Identification and characterization of a novel member of the fibroblast growth factor family.

A new member of the fibroblast growth factor (FGF) family, FGF-13, has been molecularly cloned as a result of high throughput sequencing of a human ovarian cancer cell library. The open reading frame of the novel human gene (1419 bp) encodes for a protein of 216 a.a. with a molecular weight of 22 kDa. The FGF-13 sequence contains an amino-terminal hydrophobic region of 23 a.a. characteristic of a signal secretion sequence. FGF-13 is most homologous, 70% similarity at the amino acid level, to FGF-8. Northern hybridization analysis demonstrated prominent expression of FGF-13 in human foetal and adult brain, particularly in the cerebellum and cortex. In proliferation studies with BaF3 cells, FGF-13 preferentially activates cell clones expressing either FGF receptor variant, 3-IIIc or 4. The signal transduction pathways of FGF-13 and FGF-2 were compared in rat hippocampal astrocytes. The two FGFs induce an equivalent level of tyrosine phosphorylation of mitogen-activated protein kinase (MAPK) and c-raf activation. However, FGF-13 is more effective than FGF-2 in inducing the phosphorylation of phospholipase C-gamma (PLC-gamma). Treatment of neuronal cultures from rat embryonic cortex with FGF-13 increases the number of glutamic acid decarboxylase immunopositive neurons, the level of high-affinity gamma-aminobutyric acid (GABA) uptake, and choline acetyltransferase enzyme activity. The GABAergic neuronal response to FGF-13 treatment is rapid with a significant increase occurring within 72 h. We have identified a novel member of the FGF family that is expressed in the central nervous system (CNS) and increases the number as well as the level of phenotypic differentiation of cortical neurons in vitro.
Evaluation of MR markers that predict survival in patients with newly diagnosed GBM prior to adjuvant therapy

Purpose Glioblastoma Multiforme (GBM) is the most common and lethal primary brain tumor in adults. The goal of this study was to test the predictive value of MR parameters in relation to the survival of patients with newly diagnosed GBM who were scanned prior to receiving adjuvant radiation and chemotherapy. Methods The study population comprised 68 patients who had surgical resection and were to be treated with fractionated external beam radiation therapy and chemotherapy. Imaging scans included anatomical MRI, diffusion and perfusion weighted imaging and 1H MRSI. The MR data were acquired 3–5 weeks after surgery and approximately 1 week before treatment with radiation therapy. The diffusion, perfusion and spectroscopic parameter values were quantified and subjected to proportional hazards analysis that was adjusted for age and scanner field strength. Results The patients with larger lesion burden based upon volumes of anatomic lesions, volume of CNI2 (number of voxels within the T2 lesion having choline to NAA index >2), volume of CBV3 (number of pixels within the T2 lesion having relative cerebral blood volume >3), and volume of nADC1.5 (number of pixels within the T2 lesion having normalized apparent diffusion coefficient <1.5) had a higher risk for poor outcome. High intensities of combined measures of lactate and lipid in the T2 and CNI2 regions were also associated with poor survival. Conclusions Our study indicated that several pre-treatment anatomic, physiological and metabolic MR parameters are predictive of survival. This information may be important for stratifying patients to specific treatment protocols and for planning focal therapy.
Study of Spent Refractory Waste Recycling from Metal Manufacturers in Missouri

There are over 150 metal related companies in Missouri that discard approximately 7500 metric tons of spent refractories annually. Nearly all (∼99%) of the refractories are landfilled wasting valuable natural resources. The purpose of this research is to minimize the refractory wastes being landfilled by studying the types and quantities of spent refractories generated by these companies, the states of these wastes, and technologies for recycling and reusing them. Conducting this study in Missouri is ideal because it has a diverse group of metals (lead, aluminum, steel and copper) manufacturers and the results, therefore, should be applicable to other regions of the US and of the world. This paper reviews previously identified techniques for recycling refractory materials, summarizes data from informational surveys of metals manufacturers in the state, and highlights potential barriers to, and opportunities for, spent refractory recycling. Results from the surveys indicated that two large waste streams exist in Missouri and that identifying and implementing recycling of these two waste streams would dramatically reduce the quantity of spent refractories landfilled annually.
SPIN-(FLAVOR) PRECESSION AND SHORT WAVELENGTH VACUUM OSCILLATION AS A SOLUTION FOR THE SOLAR NEUTRINO PUZZLE

We investigate the possibility of spin-(flavor) precession combined with short wavelength vacuum oscillation as a solution for the solar neutrino puzzle. A large frozen-in magnetic field inside the sun with a neutrino magnetic moment of the order of 10-10 Bohr magneton can completely depolarize the νeL resulting in a factor of half of the emitted number. With a short wavelength vacuum oscillation and maximal mixing, the number of νeL's reaching the earth is reduced by another factor of half; this explains the Homestake chlorine experiment. The difference between the Homestake and the Kamiokande-II experiments can be attributed to the contribution to the Cherenkov radiation in the latter through the neutral current and electromagnetic interactions of the components which are inert in the former.
Localization of cytochrome oxidase (COX) activity and COX mRNA in the perirhinal and superior temporal sulci of the monkey brain.

Abstract Cytochrome oxidase (COX) activity and COX II mRNA expression were localizedin the perirhinal and superior temporal sulci of the rhesus monkey brain. In both regions, a laminar distribution of COX activity and COX II mRNA was observed. COX activity was intense in layers I and IV and were localized to the neuropil. In contrast, COX II mRNA was localized to neuronal cell bodies. In the prorhinal region, highest levels of COX II mRNA was detected in cell bodies of layers II and IV, and in the perirhinal region, in cell bodies of layers III and V–VI. In the superior temporal sulcus, COX II mRNA was detected in cell bodies of layers III and V–VI. Thus, COX II mRNA and COX activity are uniquely localized in the cortical layers and to those neurons that support cortico-cortical connections.
Gene targeting in adult rhesus macaque fibroblasts

Gene targeting in nonhuman primates has the potential to produce critical animal models for translational studies related to human diseases. Successful gene targeting in fibroblasts followed by somatic cell nuclear transfer (SCNT) has been achieved in several species of large mammals but not yet in primates. Our goal was to establish the protocols necessary to achieve gene targeting in primary culture of adult rhesus macaque fibroblasts as a first step in creating nonhuman primate models of genetic disease using nuclear transfer technology. A primary culture of adult male fibroblasts was transfected with hTERT to overcome senescence and allow long term in vitro manipulations. Successful gene targeting of the HPRT locus in rhesus macaques was achieved by electroporating S-phase synchronized cells with a construct containing a SV40 enhancer. The cell lines reported here could be used for the production of null mutant rhesus macaque models of human genetic disease using SCNT technology. In addition, given the close evolutionary relationship and biological similarity between rhesus macaques and humans, the protocols described here may prove useful in the genetic engineering of human somatic cells.
Camtasia in the Classroom: Student Attitudes and Preferences for Video Commentary or Microsoft Word Comments During the Revision Process

Abstract In the last ten years, libraries, individual departments, and professors have experimented with screen-capture software to develop edited tutorials, record in-class lectures via presentation software, and record think-aloud rationale for difficult problem sets. Moreover, screen-capture software has been used to provide visual/audio feedback for student writing. Currently, there is scant research on visual/audio feedback via screen-capture software in writing courses. The present study examines student perceptions and attitudes about two different modes and media of teacher feedback: Microsoft Word comments versus visual/audio commentary. The results indicate that the mode and medium of teacher feedback had an impact on students’ perceptions about the rhetorical context of the revision process and perceptions about the teacher/student relationship. Students who preferred the visual/audio modality of the teacher commentary videos cited their conversational quality, clarification of expectations, and reference to more global issues in writing. On the other hand, students who preferred the Microsoft Word comments were more apt to discuss its indexical quality in that students could easily revise surface level features or locate the “problem” sentence. The results also indicate that an either/or approach to teacher feedback is not necessary. Students articulated the relevance of using a combination approach in which Microsoft Word comments and the teacher commentary videos could be used for different elements or stages of the writing process. As instructors transition to teaching within online contexts and experiment with new technologies, it is important to examine the significance of the mode and medium of teacher feedback in student perceptions, participation, and writing practices.
Glutathione S-transferase polymorphisms and survival in African-American and white colorectal cancer patients.

Abstract Background : Glutathione S -transferase (GST) enzymes are involved in electrophile detoxification. The authors investigated the association between GST genotype and survival in a racially diverse, population-based cohort of colorectal cancer (CRC) patients followed for a median of 9.6 years. Methods : Interviews were conducted with 315 African-American and White CRC patients in Connecticut, 1987–1991. Tumor tissue ( n =197) was later retrieved from hospital of diagnosis and assayed using multiplex PCR (GSTM1 and GSTT1) and PCR and RFLP analysis (GSTP1). Cox proportional hazards models provided adjusted hazard ratios (HR) and 95% confidence intervals (CI). Results : Individuals with Ile/Val or Val/Val GSTP1 genotypes had a decreased risk of death (multivariate adjusted HR=0.72, 95% CI: 0.48, 1.09) relative to those with wild type (Ile/Ile). Among those who received chemotherapy, this benefit was more pronounced (HR=0.35, 95% CI: 0.16, 0.79); the interaction of reduced function GSTP1 genotype and chemotherapy was significant ( P =0.05). GSTM1 and GSTT1 genotype were not associated with survival. GSTM1, GSTT1, and GSTP1 genotype did not vary by race and did not contribute significantly to the survival disadvantage observed in African-Americans. Conclusions : In summary, GSTP1 genotype may play a role in CRC survival in African-Americans and Whites, particularly among those who receive chemotherapy.
Monitoring fire and smoke emissions with the hazard mapping system

The Hazard Mapping System (HMS) was developed in 2001 by the National Oceanic and Atmospheric Administration's (NOAA) National Environmental Satellite and Data Information Service (NESDIS) as an interactive tool to identify fires and the smoke emissions they produce over North America in an operational environment. The system utilizes 2 geostationary and 5 polar orbiting environmental satellites. Automated fire detection algorithms are employed for each of the sensors. Analysts apply quality control procedures for the automated fire detections by eliminating those that are deemed to be false and adding hotspots that the algorithms have not detected via a thorough examination of the satellite imagery. Areas of smoke are outlined by the analyst using animated visible channel imagery. A quantitative assessment of the smoke concentration is not performed at this time. However, integration of automated aerosol and smoke products into the HMS, such as the Geostationary Operational Environmental Satellite (GOES) Aerosol and Smoke Product (GASP) and the MODIS aerosol product in early 2006 and the aerosol product from the Ozone Monitoring Instrument (OMI) in late 2006 are expected to aid in providing smoke concentrations and identifying areas of smoke. HMS analysts also denote fires that are producing smoke emissions detected in satellite imagery as well as the start and end times of the emissions. These fire locations are used as input to the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. HYSPLIT utilizes a dynamic emissions rate for these fires as specified by the Blue Skies framework.
Interwoven Biology of the Tsetse Holobiont

Microbial symbionts can be instrumental to the evolutionary success of their hosts. Here, we discuss medically significant tsetse flies (Diptera: Glossinidae), a group comprised of over 30 species, and their use as a valuable model system to study the evolution of the holobiont (i.e., the host and associated microbes). We first describe the tsetse microbiota, which, despite its simplicity, harbors a diverse range of associations. The maternally transmitted microbes consistently include two Gammaproteobacteria, the obligate mutualists Wigglesworthia spp. and the commensal Sodalis glossinidius, along with the parasitic Alphaproteobacteria Wolbachia. These associations differ in their establishment times, making them unique and distinct from previously characterized symbioses, where multiple microbial partners have associated with their host for a significant portion of its evolution. We then expand into discussing the functional roles and intracommunity dynamics within this holobiont, which enhances our understanding of tsetse biology to encompass the vital functions and interactions of the microbial community. Potential disturbances influencing the tsetse microbiome, including salivary gland hypertrophy virus and trypanosome infections, are highlighted. While previous studies have described evolutionary consequences of host association for symbionts, the initial steps facilitating their incorporation into a holobiont and integration of partner biology have only begun to be explored. Research on the tsetse holobiont will contribute to the understanding of how microbial metabolic integration and interdependency initially may develop within hosts, elucidating mechanisms driving adaptations leading to cooperation and coresidence within the microbial community. Lastly, increased knowledge of the tsetse holobiont may also contribute to generating novel African trypanosomiasis disease control strategies.
Axonal projections within the brain-retrocerebral complex of the cricket, Teleogryllus commodus

The cerebral origins and axonal trajectories of neurons projecting to the retrocerebral complex of the cricket, Teleogryllus commodus, were examined in silver-intensified nickel preparations. Spatially separate groups of somata in the pars intercerebralis (PI) and in the pars lateralis (PL), commonly accepted as neurosecretory loci, were found to give rise to axons which terminate in the nervus corporis allati 2, the corpus allatum, or the corpus cardiacum. Additional findings demonstrated a distinct group of somata from the PI whose axons run in the esophageal nerve (stomatogastric nervous system), nine somata in the subesophageal ganglion with axons projecting into the nervus corporis allati 2, and also a small cluster of tritocerebral perikarya with axons terminating in the corpus cardiacum. Somata residing in the PI and PL were found to be compartmentally organized based upon the retrocerebral destinations of their axons. Possible functional consequences of these results with respect to the insect neurosecretory system are discussed.
Age dependence of the cardiac lesions induced by minoxidil in the rat.

To evaluate the age- and dose-dependence of the cardiotoxicity induced by minoxidil, histologic studies were made of the hearts of 3-, 6-, 15- and 24-month-old Sprague Dawley rats treated with either 10, 50 or 250 mg/kg of the drug p.o. daily for two consecutive days. The 10 mg/kg dose of minoxidil induced myocyte necrosis in each of the 24-month-old rats but only in one other animal (6-month-old). The 50 mg/kg dose produced necrosis in all the 15- and 24-month-old rats, but in only one of the other animals (6-month-old), while the 250 mg/kg dose induced necrosis in animals of all ages. Inflammation was present in all minoxidil-treated animals, but at each dose level it was most severe in the oldest rats. Interstitial hemorrhages were observed at all dose levels, but increased in frequency and severity with the dose of minoxidil, and at each dose level they were more severe in the oldest animals. Vascular lesions consisting of arteriolar damage and calcification were observed only in the 24-month-old animals. Thus, these data demonstrate that the cardiac lesions induced by minoxidil are more frequent and severe in older than in younger rats.
Image reconstruction on PI-lines by use of filtered backprojection in helical cone-beam CT

Recently, we have derived a general formula for image reconstruction from helical cone-beam projections. Based upon this formula, we have also developed an exact algorithm for image reconstruction on PI-line segments from minimum data within the Tam-Danielsson window. This previous algorithm can be referred to as a backprojection-filtration algorithm because it reconstructs an image by first backprojection of the data derivatives and then filtration of the backprojections on PI-line segments. In this work, we propose an alternative algorithm, which reconstructs an image by first filtering the modified data along the cone-beam projections of the PI-lines onto the detector plane and then backprojecting the filtered data onto PI-line segments. Therefore, we refer to this alternative algorithm as the filtered-backprojection algorithm. A preliminary computer-simulation study was performed for validating and demonstrating this new algorithm. Furthermore, we derive a practically useful expression to accurately compute the derivative of the data function for image reconstruction. The proposed filtered-backprojection algorithm can reconstruct the image within any selected ROI inside the helix and thus can handle naturally the long object problem and the super-short scan problem. It can also be generalized to reconstruct images from data acquired with other scanning configurations such as the helical scan with a varying pitch.
Chemoattractant lymphokines specific for the helper/inducer T-lymphocyte subset☆☆☆

Abstract The cellular content of T-lymphocyte-rich inflammatory sites is dependent in part on the in situ elaboration of chemoattractant factors. We have previously described three T-lymphocytespecific chemoattractant lymphokines; a chemokinetic factor, lymphocyte chemoattractant factor (LCF, MW 56,000), and two distinct lymphocyte migration inhibitory factors (LyMIF 75K , MW 75,000; and LyMIF 35K , MW 35,000). These factors are produced by human T cells in response to antigen, concanavalin A, or histamine stimulation. In this communication, we report that LCF and LyMIF 35K are produced by OKT8 + (suppressor/cytotoxic) and OKT4 + (helper/inducer) lymphocytes, respectively, and are selectively chemoattractant for the OKT4 4 lymphocyte subset. LyMIF 75K is produced by OKT4 + cells and inhibits both OKT4 + and OKT8 + lymphocyte migration. Production of LCF and LyMIF 35K by infiltrating lymphocyte subsets may be one mechanism whereby unactivated helper/inducer T lymphocytes are selectively recruited to sites of inflammation.
Changing concepts in the therapy of lung abscess: a twenty year survey.

Worsening in the prognosis of patients with lung abscess in the past four years prompted us to bring our previous observations’ to date. The 15 years from 1941 to 1955 in our experience, were marked by steady and dramatic improvement in the results in this disease. In the past four years this trend has been reversed. Material and Method of Treatment This series consists of 87 cases; these can be divided readily into four groups (Table 1). Group A: 1941-1944; 19 cases; Group B: 1945-1951: 29; Group C: 1952-1955: 17; Group D: 1955 to date: 22. Group A: 1941-1944: The Sulfonamide Period; treatment consisted of supportive measures, bronchoscopic aspirations, postural drainage, sulfonamides and surgical procedures. Bronchoscopy was used routinely in all cases, both as a diagnostic tool and also as a means of cleansing the tracheal bronchial tree. Sulfathiazole and sulfadiazine were used in various dosages. Surgical procedures were simple incision and drainage or two stage pneumonotomies. Group B: 1945-1951: The Penicillin Period; this drug was used both parenterally and by aerosol. Supportive treatment was unchanged. Surgical procedures were the same as Group A except from 1949 on, resection was carried out in the majority of cases requiring surgical intervention. Group C: 1952-1955: The Antibiotic and Trypsint Period; supportive treatment remained unchanged. The antibiotics used were oxytetracychine, and penicillin. The drug used was selected from sensitivity studies of material obtained at bronchoscopy. Aerosol trypsin administration in a dosage of 125 mg. in 2 cc. of diluent daily, was used in each instance for five to ten days and then every second day for a period of from two to four weeks. Surgery during this period was resectional. No surgical drainage procedure was done. Group D: 1955-1959: The latrogenic Period; supportive treatment remained unchanged. Culture and sensitivity studies determined the anti
Tissue distribution and molecular characterization of chicken isolates of Toxoplasma gondii from Peru.

The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii antibodies in sera of 50 free-range chickens (Gallus domesticus) from Peru was 26% on the basis of the modified agglutination test (MAT). Hearts, pectoral muscles, and brains of seropositive (MAT ≥1:5) chickens were bioassayed individually in mice. Tissues from the remaining 37 seronegative chickens were pooled and fed to 2 T. gondii–free cats. Feces of cats were examined for oocysts; they did not shed oocysts. Toxoplasma gondii was isolated from the hearts of 10 seropositive chickens but not from their brains and pectoral muscles. Genotyping of these isolates using the SAG2 locus indicated that 7 isolates were type I and 3 were type III. Six of the 7 type-I isolates were avirulent for mice, which was unusual because type-I isolates are considered virulent for mice. The T. gondii isolates were from chickens fr...
RISK AVOIDANCE STRATEGIES IN VENTURE CAPITAL MARKETS

This research compares risk avoidance strategies employed by business angels and venture capital firm investors. It finds that differences in their approaches to evaluating risk lead them to hold predictably different views of the dangers of market and agency risk. the former tend to rely upon the entrepreneur to protect them from losses due to market risk. Consequently, they are more concerned with agency risk than market risk. the latter are more concerned with market risk because they have learned to protect themselves contractually from agency risk using boilerplate contractual terms and conditions. A likely result of their different approaches to avoiding risk is a segmentation of venture capital markets, which has important implications for both entrepreneurs and future research.
Classical conditioning of an odor preference in 3-day-old rats

Deprived 3-day-old rat pups developed (and retained for 24 hr) a preference for a novel odor that preceded oral infusions of milk. Conditioned preferences developed only when pups received the odor-milk pairing in a warm ambience. The reinforcing properties of milk infusion also depended on the pups' deprivational state, in that nondeprived pups failed to show a conditioned odor preference. These findings indicate that 3-day-old rats are capable of appetitive associative learning.
Education of the modern surgical resident: novel approaches to learning in the era of the 80-hour workweek.

Implementation of the 80-hour work week has resulted in limitations on the hours available for resident education, creating a need for innovative approaches to teach surgical residents successfully. Herein we report the methods and results of an innovative didactic learning program at a large academic surgerical residency program. Between 2004 and 2005, based on known principles of adult education and innovative learning techniques, a didactic learning program was instituted in a major academic surgery program. The course work consisted of a structured reading program using Schwartz’s Textbook of Surgery, with weekly testing and problem-based learning (PBL) groups led by surgical faculty. The residents’ progress was assessed by American Board of Surgery In-Training Examination (ABSITE) training scores before and after program implementation. A resident survey was also conduced to assess residents’ attitudes toward the new program. Results were reported as a mean, and categoric variables were compared using a paired Student’s t-test. During the academic year of the structured reading program, the mean ABSITE score improved by 10% (P = 0.02) from the previous year. The postgraduate year 4 class had the largest change, with a score increase of 17% over the previous year’s performance (P = 0.02). Survey results demonstrated that 64% of the responders agreed that the small-group PBL was preferable for achieving educational goals. Furthermore, 89% of residents responded that the PBL groups improved interaction between residents and faculty members. An innovative formal learning program based on a major surgical textbook with weekly testing and small group sessions can significantly improve surgical training in the modern era of work-hour restrictions. Furthermore, surgical trainees find this format to be innovative and useful for improving didactic teaching.
A prospective controlled trial of oral kanamycin in the prevention of neonatal necrotizing enterocolitis

Alimentary kanamycin, 15 mg/kg/day, was given as prophylaxis for neonatal necrotizing enterocolitis in a prospective study. Newborn infants of less than 1,500 gm birth weight who survived until initiation of alimentary nutrition at the University of Florida Neonatal Intensive Care Unit were admitted to a control or study group based on the last digit of the hospital number. Alimentary kanamycin was not absorbed; all blood levels determined were less than 0.5 μg/ml. The two groups had similar gestational ages, birth weights, severity of neonatal illness, and frequency of therapeutic procedures. In the study group of 35 infants, none developed neonatal necrotizing enterocolitis, whereas five cases occurred in the 40 control infants (p=0.038).
Comparison of urinary hyperglycosylated human chorionic gonadotropin concentration with the serum triple screen for Down syndrome detection in high-risk pregnancies

Abstract Objective: Both modest screening performance and declining patient and physician acceptance have stimulated interest in alternative markers to the triple screen for the detection of Down syndrome. Our purpose was to compare the concentration of a single urinary analyte, hyperglycosylated human chorionic gonadotropin, with the serum triple screen (α-fetoprotein, human chorionic gonadotropin, and unconjugated estriol concentrations combined with age) for second-trimester Down syndrome detection. Study Design: Urine and blood were obtained from pregnant women in the second trimester undergoing genetic amniocentesis. Urinary hyperglycosylated human chorionic gonadotropin concentration and serum triple-screen values were measured. Individuals undergoing amniocentesis because of abnormal triple-screen results were excluded. Individual Down syndrome risks on the basis of urinary hyperglycosylated human chorionic gonadotropin concentration plus maternal age and on the basis of the triple-screen results were calculated. For each algorithm the sensitivity and false-positive rate for Down syndrome detection at different risk thresholds were determined. From these values receiver operating characteristic curves were constructed, and the area under the curve was determined for each algorithm. Finally, the performance of a new combination in which urinary hyperglycosylated human chorionic gonadotropin concentration replaced serum human chorionic gonadotropin concentration in the triple screen was ascertained. Results: We studied 24 pregnancies complicated by Down syndrome and 500 unaffected pregnancies between 14 and 22 weeks' gestation in a mostly white (93.5%) population undergoing amniocentesis primarily because of advanced maternal age. The sensitivity and false-positive rate for urinary hyperglycosylated human chorionic gonadotropin concentration were 75.0% and 5.6%, respectively, whereas those for the triple screen were 75.0% and 33.2%, respectively. Urinary hyperglycosylated human chorionic gonadotropin concentration was superior to the triple screen (area under the curve, 0.9337 vs 0.7887; P =.02). The substitution of urinary hyperglycosylated human chorionic gonadotropin concentration for serum human chorionic gonadotropin concentration in the triple screen resulted in a 91.7% sensitivity at a 10.0% false-positive rate, versus a 54.2% sensitivity for the traditional triple screen at the same false-positive rate. Conclusion: The performance of urinary hyperglycosylated human chorionic gonadotropin concentration was statistically superior to that of the serum triple screen in a high-risk population. The use of urinary hyperglycosylated human chorionic gonadotropin concentration as an alternative test or substitution of this measurement for serum human chorionic gonadotropin concentration in the triple screen would improve diagnostic accuracy and address many current concerns related to the triple screen. (Am J Obstet Gynecol 2000;183:1114-8.)
A Method for the Determination of α-Dicarbonyl Compounds

Abstract A method is reported for determining the α-dicarbonyls glyoxal, methylglyoxal, and diacetyl. The carbonyls were reacted at pH 8 with .05% aqueous solution of o -phenylenediamine for 4h at 25°C to form quinoxalines. The derivatives were extracted with chloroform, transferred to methanol, and separated by HPLC on a Supelcosil LC-18 column with methanol water as the mobile phase. The method was applied to several dairy cultures and cheese varieties. The amounts of glyoxal, methylglyoxal, and diacetyl in the cultures varied from 2 to 227, 0 to 7, and 1 to 11µg/ml, respectively, depending on the species, strain, and culture medium.
Relating particle formation to salt‐ and pH‐dependent phase separation of non‐native aggregates of alpha‐chymotrypsinogen a

ABSTRACT Visible and subvisible particle formation during the storage of protein solutions is of increasing concern for pharmaceutical products. Previous work (Li Y, Ogunnaike BA, Roberts CJ. 2010. J Pharm Sci 99:645–662) showed that the model protein, alpha‐chymotrypsinogen A (aCgn), forms non‐native aggregates under accelerated (heated) conditions, but the size and morphology of the resulting aggregates depended sensitively on pH and NaCl. Here, it is shown that aggregates created as high‐molecular‐weight soluble aggregates undergo a pH‐ and salt‐dependent reversible phase transition to a condensed or insoluble phase of suspended microparticles, whereas monomers remain completely soluble in the same regime. The location of the phase boundary is quantitatively consistent with the different regimes of kinetic behavior observed previously for aCgn. This suggests that the while kinetics is important for controlling the rates of monomer loss during non‐native aggregation, it may be possible to tune solution thermodynamics and phase behavior to suppress otherwise soluble aggregates from propagating to form visible or large subvisible particles. Interestingly, the aggregate phase boundary is sensitive to the identity of salt anions in solution, highlighting the importance of electrostatics and preferential salt interactions in mediating aggregate condensation and particle formation.
Xanthine oxidase catalyzed binding of 1-nitropyrene to DNA.

Xanthine oxidase, a mammalian nitroreductase, catalyzed the binding of [3H]1-nitropyrene to DNA. The binding was dependent on the presence of hypoxanthine and was inhibited by allopurinol, a specific xanthine oxidase inhibitor. These data support the hypothesis that nitroreduction is a necessary step in the metabolic activation of 1-nitropyrene to a bacterial mutagen.
Improving wireless link delivery ratio classification with packet SNR

Accurate link delivery ratio prediction is crucial to routing protocols in wireless mesh network. Since predicting delivery ratio directly usually requires excessive probing packets, it has been suggested to use packet SNR to predict delivery ratio, as SNR is a measure easy to obtain and "free" with every received packet. Unfortunately, several previous studies have shown that a simple direct mapping between SNR and delivery ratio values is often impossible. In this paper, we formulate the delivery ratio prediction problem as a classification problem (predicting link to be "good" or "bad), and apply various statistical classification algorithms (k-NN, kernel methods, and support vector machines) to it. We obtain the temporal data of link delivery ratios and SNR's from a measurement trace of a live wireless mesh network, and analyze the effectiveness of using SNR to enhance delivery ratio classification. Contrary to the pessimistic conclusion of previous works, we find that by incorporating SNR information in addition to historical delivery ratio data, the classification accuracy is improved in all the algorithms we used, with an average reduction of 8-10% of errors compared with using delivery ratio data alone. We therefore conclude that adding SNR can be an attractive alternative when designing a wireless link delivery ratio prediction protocol
Characterizing functional lung heterogeneity in COPD using reference equations for CT scan-measured lobar volumes

Abstract Background CT scanning is increasingly used to characterize COPD. Although it is possible to obtain CT scan-measured lung lobe volumes, normal ranges remain unknown. Using COPDGene data, we developed reference equations for lobar volumes at maximal inflation (total lung capacity [TLC]) and relaxed exhalation (approximating functional residual capacity [FRC]). Methods Linear regression was used to develop race-specific (non-Hispanic white [NHW], African American) reference equations for lobar volumes. Covariates included height and sex. Models were developed in a derivation cohort of 469 subjects with normal pulmonary function and validated in 546 similar subjects. These cohorts were combined to produce final prediction equations, which were applied to 2,191 subjects with old GOLD (Global Initiative for Chronic Obstructive Lung Disease) stage II to IV COPD. Results In the derivation cohort, women had smaller lobar volumes than men. Height positively correlated with lobar volumes. Adjusting for height, NHWs had larger total lung and lobar volumes at TLC than African Americans; at FRC, NHWs only had larger lower lobes. Age and weight had no effect on lobar volumes at TLC but had small effects at FRC. In subjects with COPD at TLC, upper lobes exceeded 100% of predicted values in GOLD II disease; lower lobes were only inflated to this degree in subjects with GOLD IV disease. At FRC, gas trapping was severe irrespective of disease severity and appeared uniform across the lobes. Conclusions Reference equations for lobar volumes may be useful in assessing regional lung dysfunction and how it changes in response to pharmacologic therapies and surgical or endoscopic lung volume reduction.
A stochastic approach to delay compensation in network-based distributed intelligent control systems

A state estimation and state feedback control law has been formulated in a stochastic setting, based on the principles of minimum variance filtering and dynamic programming, for delay compensation in network-based distributed intelligent control systems. The proposed estimation and control law for delay compensation is essentially an extension of the conventional linear quadratic Gaussian. >
Evolution of design features in the coding of species-specificity.

Reproductive isolation between species is the major factor responsible for the evolution of species-specificity in communication signals. However, the actual physical or chemical structure of signals may be determined by a number of factors such as the physical laws regulating the transmission of signal energy, locatability, the functional properties of sensory organs, the physical characteristics of the habitats in which communication occurs, and prey-predator relationships. This fact implies that there is some degree of predictability in design features of signaling systems.
Outline of a theory of turbulent shear flow

In this paper the spatial variations and spectral structure of steady-state turbulent shear flow in channels are investigated without the introduction of empirical parameters. This is made possible by the assumption that the non-linear momentum transport has only stabilizing effects on the mean field of flow. Two constraints on the possible momentum transport are drawn from this assumption: first, that the mean flow will be statistically stable if an Orr-Sommerfeld type equation is satisfied by fluctuations of the mean; second, that the smallest scale of motion that can be present in the spectrum of the momentum transport is the scale of the marginally stable fluctuations of the mean. Within these two constraints, and for a given mass transport, an upper limit is sought for the rate of dissipation of potential energy into heat. Solutions of the stability equation depend upon the shape of the mean velocity profile. In turn, the mean velocity profile depends upon the spatial spectrum of the momentum transport. A variational technique is used to determine that momentum transport spectrum which is both marginally stable and produces a maximum dissipation rate. The resulting spectrum determines the velocity profile and its dependence on the boundary conditions. Past experimental work has disclosed laminar, ‘transitional’, logarithmic and parabolic regions of the velocity profile. Several experimental laws and their accompanying constants relate the extent of these regions to the boundary conditions. The theoretical profile contains each feature and law that is observed. First approximations to the constants are found, and give, in particular, a value for the logarithmic slope (von Karman's constant) which is within the experimental error. However, the theoretical boundary constant is smaller than the observed value. Turbulent channel flow seems to achieve the extreme state found here, but a more decisive quantitative comparison of theory and experiment requires improvement in the solutions of the classical laminar stability problem.
Dengue fever and dengue hemorrhagic fever: a review of the history, transmission, treatment, and prevention.

Although not a new disease dengue fever represents a serious emerging infectious disease that can have dire consequences including death. Recent epidemics and the 1998 pandemic in which more than 1.2 million cases of dengue fever and dengue hemorrhagic fever (DHF) were reported to the World Health Organization (WHO) from 56 countries have resulted in dengue fever becoming a major international health concern. In May 1993 the World Health Assembly recognizing the rising significance and continued spread of the disease approved a resolution entitled "Dengue prevention and control" that identified dengue and its more serious syndromes as a priority of the Organization. A global strategy on dengue and DHF was adopted in 1995. Today dengue is considered the most important arboviral disease of humans with an estimated 50 to 100 million dengue infections and 200000 to 500000 cases of DHF occurring annually as of 2000. Hence an increased understanding of its background and prevalence clinical presentation transmission treatment and prevention is needed for pediatricians and infectious diseases specialists alike. (excerpt)
Assessing substance abuse treatment provider training needs: Screening skills

Screening instruments for substance abuse can be expeditious and effective clinical tools. A training needs assessment conducted with a randomly selected sample of substance abuse treatment providers (n = 1684) in licensed facilities in New England identified the adequacy of training, interest in training, clinical skill, and training need in the use of 13 substance abuse screening instruments. The results revealed that New England substance abuse treatment providers are not skilled in the use of screening instruments and have a high level of training need in this area. Differences in screening skill were found among the New England states. In addition, women and those with less treatment experience have lower screening skill; similarly, women, those having less experience in the field, and social workers and nurses evidenced higher training need in screening. The discussion considers skill, adequacy of training, training interest, and training need. The conclusion suggests that one approach to the coexisting increased need for screening skills due to managed care requirements and the lack of interest in these skills is to study managed care marketplace demands to determine training priorities.