cssi/SciSciGPT-SciSciNet huggingface dataset:
Female-initiated barrier methods for the prevention of STI/HIV: Where are we now? where should we go?

The female condom has been on the US marker for over 8 years and was hailed as a method that would allow women greater control in protecting themselves against unwanted pregnancy and sexually transmitted infections. However, since its launch, promotion of the female condom has met with challenges that vary from provider bias against the device, concerns about efficacy, and doubts about whether it will be used. While daunting, many of these challenges are not unique to the female condom. In fact, they parallel those of the tampon when it was first promoted in the US for menstrual hygiene in the early 1930s. Many providers were initially opposed to the tampon: early users found the tampon inadequate. Ten years after the introduction of the tampon and despite mass marketing, acceptability was mixed and use was modest (25% prevalence in a 26-city survey). Similar to female condom use observed in current-day prospective studies, users did not use the tampon exclusively or even predominantly. The story of the tampon demonstrates that a method does not have to be adopted by all users immediately to play an important role, and that even initially controversial methods can become widely accepted as mainstream. The early history of the tampon sheds perspective, and hope, on where we stand with the female condom. While much-needed work is under way to develop microbicides, we should take advantage of the fact that the female condom is already available and promote it to those in need now.
Responses and afferent pathways of C1–C2 spinal neurons to gastric distension in rats

Some evidence shows that the upper cervical spinal cord might play an important role in propriospinal processing as a sensory filter and modulator for visceral afferents. The aims of this study were to determine (1) the responses of C1–C2 spinal neurons to gastric distension and (2) the relative contribution of vagal and spinal visceral afferent pathways for transmission of gastric input to the upper cervical spinal cord. Extracellular potentials of single C1–C2 spinal neurons were recorded in pentobarbital anesthetized male rats. Graded gastric distension (20–80 mm Hg) was produced by air inflation of a latex balloon surgically placed in the stomach. Sixteen percent of the neurons (32/198) responded to gastric distension; 17 neurons were excited and 15 neurons were inhibited by gastric distension. Spontaneous activity of neurons with inhibitory responses was higher than those neurons with excitatory responses (18.1±2.7 vs. 3.8±1.7 impulses s−1, p<0.001). Twenty-eight of thirty-two (87.5%) neurons responded to mechanical stimulation of somatic fields on head, neck, ears or shoulder. Most lesion sites of neurons with excitatory responses were found in laminae V, VII; however, neurons with inhibitory responses were in laminae III, IV. Bilateral cervical vagotomy abolished responses of 4/8 neurons tested. Spinal transection at C6–C7 abolished responses of the other four neurons that still responded to gastric distension after bilateral vagotomy. Results of these data supported the concept that a group of C1–C2 spinal neurons might play a role in processing sensory information from the stomach that travels in vagal and spinal visceral afferent fibers.
Pathology of the cardiac conduction system in myotonic dystrophy: A study of 12 cases

Abstract In 12 autopsy cases of myotonic dystrophy, the most frequently observed histopathologic lesions of the cardiac conduction system were fibrosis, fatty infiltration and atrophy. Fibrosis involved the sinus node in 6 cases, atrioventricular (AV) node in 7, AV bundle in 8, bundle branches in 10 and ventricular myocardium in 11. Fatty infiltration was observed in the sinus node in two cases, AV node in two, AV bundle in six, bundle branches in one and ventricular myocardium in nine. Atrophy was prominent in the AV bundle in five and bundle branches in eight. Lymphocytes infiltrated the conduction system in three cases and were associated with myotonic dystrophy in two and varicella myocarditis in one. Ventricular myocytes were hypertrophied in seven cases, vacuolated in three and exhibited disarray in two. The distribution and extent of conduction system lesions tended to correspond to antemortem electrocardiographic abnormalities, including prolonged PR interval in six cases, intraventricular conduction delay in six and bundle branch block in four. Cardiac involvement by myotonic dystrophy may have contributed to sudden death in four cases.
Strawberry Genes and Genomics

Despite its value as a crop and potential utility as an experimental system, relatively little is known about the molecular-genetic aspects of inheritance or physiology in the cultivated strawberry (Fragaria xananassa). This lack of information exists at a time when biotechnology may offer important remedies to address traditional and contemporary challenges that growers face. An improved understanding of genome structure will hasten the development of molecular markers and unveil clues to the composition of this unique, octoploid genome. Definition of gene function will guide the generation of transgenic resources for research use and possibly toward cultivar development. This review seeks to compile and present the current knowledge state of the molecular-genetic basis of cultivated strawberry genomic form and function. Ongoing studies promise to expand the use of genomic tools and appropriate model systems to rapidly discern the structural and functional basis for traits of interest to agriculture, suc...
Ozone in Residential Air: Concentrations, I/O Ratios, Indoor Chemistry, and Exposures

Ozone concentrations were measured in indoor and outdoor residential air during the summer of 1992. Six homes located in a New Jersey suburban area were chosen for analysis, and each home was monitored for 6 days under different ventilation and indoor combustion conditions. The 5-hour average ozone concentration outdoors over the monitoring period was 95 ± 36 ppbv. One third of the days exceeded the National Ambient Air Quality Standard (NAAQS), one-hour maximum concentration of 120 ppb. The mean indoor to outdoor (I/O) ratios of ozone concentration ranged from 0.22 ± 0.09 to 0.62 ± 0.11, depending upon ventilation rate and indoor gas combustion. The presence of indoor gas combustion can significantly decrease the I/O ratio. Because of the great amount of time that people spend indoors, the indoor residential exposures were estimated to account for 57% of the total residential exposures. One type of the possible gas-phase reactions for indoor ozone, the reaction of ozone with a volatile organic compound containing unsaturated carbon-carbon bonds, is discussed with some supporting evidence provided in the study.
Quantum Sized Gold Nanoclusters with Atomic Precision

Gold nanoparticles typically have a metallic core, and the electronic conduction band consists of quasicontinuous energy levels (i.e. spacing δ ≪ kBT, where kBT is the thermal energy at temperature T (typically room temperature) and kB is the Boltzmann constant). Electrons in the conduction band roam throughout the metal core, and light can collectively excite these electrons to give rise to plasmonic responses. This plasmon resonance accounts for the beautiful ruby-red color of colloidal gold first observed by Faraday back in 1857.On the other hand, when gold nanoparticles become extremely small (<2 nm in diameter), significant quantization occurs to the conduction band. These quantum-sized nanoparticles constitute a new class of nanomaterial and have received much attention in recent years. To differentiate quantum-sized nanoparticles from conventional plasmonic gold nanoparticles, researchers often refer to the ultrasmall nanoparticles as nanoclusters.In this Account, we chose several typical sizes of ...
THE BINARY REARRANGEMENT COLLISION

The theory of the general binary collision is discussed, and it is demonstrated that the rearrangement scattered amplitude can be derived from the integral equation which is convenient for determining the direct (no rearrangement of particles) scattered amplitudes. As a consequence, it is shown that no ambiguity in matrix element for the rearrangement amplitude in Born approximation exists.
Forespore-specific disappearance of the sigma-factor antagonist SpoIIAB : implications for its role in determination of cell fate in Bacillus subtilis

Endospore formation in Bacillus subtilis is a morphologically complex process in which the bacterium divides into two compartments (forespore and mother cell) that follow different developmental paths. Compartment-specific transcription in the forespore is initiated by RNA polymerase containing sigma F, and results in the forespore-specific production of sigma G, which directs most of the subsequent forespore-specific transcription. The activity of sigma F is thought to be restricted to the forespore by the sigma factor antagonist SpoIIAB. We used antibodies against SpoIIAB to monitor its accumulation during sporulation. We found that SpoIIAB accumulates early after the initiation of sporulation, and that it was present in the mother-cell compartment 2h after sigma F became active in the forespore. SpoIIAB disappeared preferentially from the forespore during development, and its disappearance from the forespore compartment correlated with the activation of sigma G in that compartment, raising the possibility that SpoIIAB may be involved regulating sigma G activity. We tested whether SpoIIAB could antagonize sigma G activity by replacing the sigma F-dependent promoter that drives expression of spoIIIG, the structural gene for sigma G, with a sigma H-dependent promoter. This resulted in a lytic phenotype that was suppressed by the simultaneous expression of a plasmid-borne copy of spoIIAB. This suggests that SpoIIAB can suppress this effect of sigma G expression. Moreover, these cells formed spores efficiently.(ABSTRACT TRUNCATED AT 250 WORDS)
Role of Estrogen Replacement Therapy in Memory Enhancement and the Prevention of Neuronal Loss Associated With Alzheimer’s Disease

Recent evidence supports a role for estrogens in both normal neural development and neuronal maintenance throughout life. Women spend 25-33% of their life in an estrogen-deprived state and retrospective studies have shown an inverse correlation between dose and duration of estrogen replacement therapy (ERT) and incidence of Alzheimer's disease (AD), suggesting a role for estrogen in the prevention and/or treatment of neurodegenerative diseases. To explore these observations further, an animal model was developed using ovariectomy (OVX) and ovariectomy with estradiol replacement (E2) in female Sprague-Dawley rats to mimic postmenopausal changes. Using an active-avoidance paradigm and a spatial memory task, the effects of estrogen deprivation were tested on memory-related behaviors. OVX caused a decline in avoidance behavior, and estrogen replacement normalized the response. In the Morris water task of spatial memory, OVX animals showed normal spatial learning but were deficient in spatial memory, an effect that was prevented by estrogen treatment. Together these data indicate that OVX in rats results in an estrogen-reversible impairment of learning/memory behavior. Because a plethora of information has been generated that links decline in memory-related behavior to dysfunction of cholinergic neurons, the effects of estrogens on cholinergic neurons were tested. We demonstrated that OVX causes a decrease in high affinity choline uptake and choline acetyltransferase activity in the hippocampus and frontal cortex; ERT reverses this effect. Further, we showed that estrogens promote the expression of mRNA for brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), 2 neurotrophic substances that have been shown to ameliorate the effects of age and injury on cholinergic neurons. Tissue culture models were used to evaluate whether estrogen treatment increases the survival of neurons when exposed to a variety of insults. 17-beta-Estradiol (beta-E2) protects cells from the neurotoxic effects of serum deprivation and hypoglycemia in human neuroblastoma cell lines. We have also observed that 17-alpha-estradiol (alpha-E2), a weak estrogen, shows neuroprotective efficacy in the SK-N-SH cell line at concentrations equivalent to beta-E2. Finally, we have observed that tamoxifen, a classic estrogen antagonist, blocks only one-third of the neuroprotective effects of either alpha-E2 or beta-E2. Collectively, these results indicate that estrogen is behaviorally active in tests of learning/ memory; activates basal forebrain cholinergic neurons and neurotrophin expression; and is neuroprotective for human neuronal cultures. We conclude that estrogen may be a useful therapy for AD and other neurodegenerative diseases.
Optical Control of Neuronal Inhibition with Genetically Engineered Light Inhibited GABAA Receptors (Li-GABARs)

GABA is the main inhibitory neurotransmitter in the brain, acting primarily at ionotropic GABAA receptors. The α subunit is critical in determining GABAA receptor functional properties and pharmacological regulation. There are six α subunit subtypes that are differentially expressed in the nervous system but few selective antagonists are available to dissect the functional role of those subtypes in neurons. We have therefore engineered α subunit specific light inhibited GABAA receptors (Li-GABARs). We generated α subunits with a cysteine mutation that allows attachment of a photoswitchable tethered ligand (PTL) consisting of a cysteine reactive maleimide group, a photoisomerizable azobenzene core and a variable GABAR ligand. Using cysteine-scanning mutagenesis we identified optimal photoswitch attachment sites near the GABA binding pocket for both α1 and α5 subunits, and tested multiple PTLs to produce maximal light dependent block of GABAR activity while minimally affecting basal receptor properties. We recorded from hippocampal slices expressing Li-GABARs and found evidence that α5, but not α1 containing receptors counteract NMDA receptor dependent synaptic depolarization. This novel interaction could provide a basis for the regulation of synaptic plasticity and memory by α5 receptors. This approach in general provides a strategy to study the role of specific GABAA receptor subunits and their importance in neuronal function and disease.
Maskless Photolithography Using an Epifluorescent Microscope for Microfluidic Applications

We present a technique for fabricating molds suitable for casting PDMS based microfluidic devices using equipment readily available to most microfluidic researchers, namely an epi-fluorescent microscope. By focusing the UV light emitted from the Hg arc lamp, we demonstrate the ability to direct-write photoresist features with a minimum resolution of 45 μm. A major advantage of this technique is its low-cost, both in terms of capital investment and on-going expenditures. Furthermore, by using a motorized stage, we can quickly fabricate a design on demand, eliminating the need, cost, and time required for a photomask. We demonstrate this technique using dry-film resist, due to its low-cost, ease of application, and less stringent safety protocols. In the future, we plan to expand our efforts to higher resolution photoresists such as SU-8.Copyright © 2011 by ASME
Scholarship in science education

Science education reform efforts set expectations for K-12 education to produce scientifically literate individuals. Implicit in this reform is the need for preservice teachers to be engaged in learning that builds their knowledge, understanding, and ability toward good science teaching. In this paper, I describe some of the experiences in science education for preservice elementary teachers and their reactions to the activities as indicated by their responses on an exit survey. The preservice teachers assess the effectiveness of each activity based on their expectations of the course, and the extent to which the activities are reproducible in elementary classrooms.
Integrable analogue active filters for implementation in MOS technology

A design method for MOS-compatible analogue active filters that use only integrating amplifiers and ratios of capacitors is discussed. The circuits retain most of the implementation advantages of sampled-data switched-capacitor filters, but are complementary to switched-capacitor filters in providing better and more predictable performance at high frequencies. The effects of circuit parasitics and amplifier nonidealities are discussed and experimental results are presented to illustrate the performance.
Telivision… And six to grow on

(1987). Telivision… And six to grow on. American Journal of Distance Education: Vol. 1, No. 2, pp. 34-43.
“Worth a Lot of Negro Votes”: Black Voters, Africa, and the 1960 Presidential Campaign

In July 1960 some 280 African students awarded scholarships in the United States stood poised for an extraordinary opportunity. Four years of college would vault them into the educated elites of their countries and provide crucial intellectual infrastructure as their nations moved toward independence. The students had scholarships; their communities had raised money for expenses. Just one obstacle remained: passage to America. And as the start of the school year neared, their journey seemed in jeopardy. An organization dedicated to helping these students, the African-American Students Foundation (aasf), did not have the funds to bring them to the United States. Wealthier foundations said their money was committed elsewhere. When the aasf appealed to the U.S. State De partment for help, officials consistently rejected their pleas. Yet when the Joseph P. Ken nedy Jr. Foundation pledged the funds needed to get the students to the United States, Senator Hugh Scott, a Pennsylvania Republican, strode onto the Senate floor to accuse "the long arm" of the Kennedy family of attempting to "take over the function of the Government in advance of an election."1
Heat Transfer Characteristics of Mixed Electroosmotic and Pressure Driven Flows Under Constant Heat Flux

Analytical solution for the heat transfer characteristics of steady electroosmotic flows with an arbitrary pressure gradient are obtained for two-dimensional straight micro-channels. Both thermally developing and fully developed regions are considered for hydraulically fully developed mixed flows under isoflux channel wall conditions. In mixed flow cases, the governing equation for energy is not separable in general. Therefore, we introduced a new method that considers the extended Graetz problem. Heat transfer characteristics are presented for low Reynolds number micro-flows where the viscous and electric field terms are very dominant. Our analytical techniques are verifled by obtaining an excellent agreement with existing literature for slug, pressure driven, and pure electroosmotic flow cases. In the fully developed region, the Nusselt number of mixed flow is independent of the thermal Peclet number for a particular Joule heat and imposed surface heat flux. The entry length of mixed flow significantly depends on the applied pressure gradient to the electroosmotic flow.Copyright © 2005 by ASME
Frequency and Pattern of Documented Diagnostic Features and the Age of Autism Identification

Objective The DSM-IV-TR specifies 12 behavioral features that can occur in hundreds of possible combinations to meet diagnostic criteria for autism spectrum disorder (ASD). This paper describes the frequency and variability with which the 12 behavioral features are documented in a population-based cohort of 8-year-old children under surveillance for ASD, and examines whether documentation of certain features, alone or in combination with other features, is associated with earlier age of community identification of ASD. Method Statistical analysis of behavioral features documented for a population-based sample of 2,757 children, 8 years old, with ASD in 11 geographically-defined areas in the US participating in the Autism and Developmental Disabilities Monitoring Network in 2006. Results The median age at ASD identification was inversely associated with the number of documented behavioral features, decreasing from 8.2 years for children with only seven behavioral features to 3.8 years for children with all 12. Documented impairments in nonverbal communication, pretend play, inflexible routines, and repetitive motor behaviors were associated with earlier identification, whereas impairments in peer relations, conversational ability, and idiosyncratic speech were associated with later identification. Conclusions The age dependence of some of the behavioral features leading to an autism diagnosis, as well as the inverse association between age at identification and number of behavioral features documented, have implications for efforts to improve early identification. Progress in achieving early identification and provision of services for children with autism may be limited for those with fewer ASD behavioral features, as well as features likely to be detected at later ages.
The polarographic determination of small amounts of chromium in calcium

Abstract A polarographic method, for the determination of small amounts of chromium in calcium metal is proposed. The diffusion current of the first chromium wave, occurring at -1.0 volt vs. the saturated calomel electrode in 1M calcium chloride, was found to bo directly proportional to the concentration. Factors affecting the diffusion current are discussed, and optimum, conditions for the determination are described.
Enhancing Android accessibility for users with hand tremor by reducing fine pointing and steady tapping

Smartphones and tablets with touchscreen have demonstrated potential to support the needs of individuals with motor impairments such as hand tremor. However, those users still face major challenges with conventional touchscreen gestures. These challenges are mostly caused by the fine precision requirement to disambiguate between targets on small screens. To reduce the difficulty caused by hand tremor in combination with small touch targets on the screen, we developed an experimental system-wide assistive service called Touch Guard. It enables enhanced area touch and a series of complementary features. This service provides the enhanced area touch feature through two possible disambiguation modes: magnification and descriptive targets list. In a laboratory study with motor-impaired users, we compared both modes to conventional tapping and tested Touch Guard with real-world applications. Targets list based disambiguation was more successful, reducing the error rate by 65% compared to conventional tapping. In addition, several challenges and design implications were discovered when presenting new touchscreen interaction techniques to users with motor impairments. As the experimental product of an intern research project at Google, Touch Guard demonstrates broad potential for solving accessibility issues for people with hand tremor using their familiar mobile devices, instead of high-cost hardware.
An equivalence between two algorithms for quadratic programming

In this paper, we demonstrate that the Van de Panne—Whinston symmetric simplex method when applied to a certain implicit formulation of a quadratic program generates the same sequence of primal feasible vectors as does the Von Hohenbalken simplicial decomposition algorithm specialized to the same program. Such an equivalence of the two algorithms extends earlier results for a least-distance program due to Cottle—Djang.
Characterization of the human TESTIN gene localized in the FRA7G region at 7q31.2.

Cancer-associated chromosomal aberrations often involve regions containing fragile sites. FRA7G is a common aphidicolin-inducible fragile site at 7q31.2, showing loss of heterozygosity in human malignancies. To investigate the structure of FRA7G, we constructed a bacterial artificial chromosome contig spanning the region between marker D7S486 and Met H. Analysis of the FRA7G sequence allowed us to identify a gene encoding a 421-amino-acid protein with three LIM domains and 89% identity to murine Testin. We determined the genomic structure of the human TESTIN locus and characterized three alternative transcripts. Although TESTIN mRNA is expressed in all normal human tissues examined, we observed lack of expression in 22% of cancer cell lines and 44% of the cell lines derived from hematological malignancies. We further determined that in most of these cases the inactivation of TESTIN expression is due to methylation of a CpG island. Analysis of the TESTIN coding region in 26 tumor cell lines revealed three missense mutations. Our findings suggest that TESTIN may represent a candidate tumor suppressor gene at 7q31.2.
An evaluation of the Human Biometric Sensor Interaction using hand geometry

The purpose of this paper is to extend the Human Biometric Sensor Interaction (HBSI) model to various modalities, in this case, hand geometry. As the data was collected at different times, there was a slight modification in training between group 1 and group 2. Therefore, a secondary purpose of this paper was to examine the differences in the HBSI metrics when individuals are given two different types of training (one using video training, and the other using small group lecture-style training). 151 individuals were asked to perform an enrollment transaction and three successive post-enrollment verification attempts with the hand geometry machine, and an observational analysis was performed on their interactions. This type of analysis is novel to the field of biometrics and the human interaction component has only recently received attention [1]. Using a framework developed specifically for studying various human interaction errors, the observations from hand recognition device placements were analyzed and mapped onto the HBSI error framework. Instead of categorizing a user error as a failure to enroll (FTE) or failure to acquire (FTA), a more comprehensive categorization of these errors were developed. Both incorrect and correct interaction errors were coded and binned in appropriate categories by a human observer. The results showed that hand geometry modality could fit the existing HBSI model. Furthermore, the experiment highlighted slight variations in errors due to training, which will be investigated further in another paper.
Estimating organic, local, and other price premiums in the Hawaii fluid milk market

With retail scanner data, we applied hedonic price modeling to explore price premiums for organic, local, and other product attributes of fluid milk in Hawaii. Within the context of revealed preference, this analysis of organic and local attributes, under a single unified framework, is significant, as research in this area is deficient in the existing literature. This paper finds both organic and local attributes delivered price premiums over imported, conventional, whole fluid milk. However, the estimated price premium for organic milk (24.6%) is significantly lower than findings in the existing literature. Likewise, the price premium for the local attribute is estimated at 17.4%, again substantially lower compared with an earlier, stated preference study in Hawaii. Beyond that, we estimated a robust price premium of 19.7% for nutritional benefits claimed. The magnitude of this estimated coefficient reinforces the notion that nutrition information on food is deemed beneficial and valuable. Finally, package size measures the influence of product weight. With each larger package size, the estimate led to a corresponding larger price discount. This result is consistent with the practice of weight discounting that retailers usually offer with fresh packaged food. Additionally, we estimated a fairly high Armington elasticity of substitution, which suggests a relatively high degree of substitution between local and imported fluid milk when their relative price changes. Overall, this study establishes price premiums for organic, local, and nutrition benefits claimed for fluid milk in Hawaii.
A stochastic evaluation model for database organizations in data retrieval systems

Experimental work in the valuation of large scale data retrieval systems has been scarce due to its difficulty and prohibitive cost. This paper discusses a simulation model of a data retrieval system which has the effect of significantly reducing the cost of experimentation and enabling research never attempted before. The model is designed to estimate the retrieval workload of alternative data retrieval systems. These data retrieval systems can be organized under several database organizations, including inverted list, threaded list, and cellular list organizations and hybrid combinations of these systems. Effectiveness of the methodology is demonstrated by using the model to study the effect of database organizations in data retrieval systems. In particular, the impact of query complexity is analyzed.
Vocal Fold Paresis: Clinical and Electrophysiologic Features in a Tertiary Laryngology Practice

A retrospective chart review was performed at the senior author's voice disorder clinic to report the symptoms, signs, and laryngeal electromyography (LEMG) data of patients presenting with vocal fold paresis (VFP) in a tertiary laryngology academic practice over a 4-year period. Medical records of 739 patients presenting to the clinic with a chief complaint of dysphonia (for 2000-2004) were assessed. History intake forms, strobovideolaryngoscopy images, and LEMG reports were reviewed for all patients with a clinical diagnosis of VFP. Of the 739 patients presenting to the clinic with voice complaints, 195 were initially diagnosed with either vocal fold paralysis or VFP (26.4%). Only 13 out of 739 patients (1.8%) with voice complaints were diagnosed with LEMG-confirmed unilateral or bilateral VFP. The most common findings on strobovideolaryngoscopy were vocal fold bowing (70%), incomplete closure (62%), and increased vibratory amplitude (38%). Seventy percentage of the patients had unilateral VFP, predominantly isolated recurrent laryngeal nerve (RLN) disease. Only 9% had unilateral superior laryngeal nerve (SLN) involvement. The most common LEMG abnormality was reduced recruitment of motor units. In our voice center, VFP was a relatively uncommon diagnostic entity. Despite the low prevalence, VFP needs to be considered in all patients who present with dysphonia. Further study is needed to examine the prevalence of "abnormal" LEMG studies in an asymptomatic control population, and to determine the utility of LEMG in the evaluation and management of dysphonia. In the same way that strobovideolaryngoscopy has been critically evaluated in the past, there is also a need to determine how commonly LEMG contributes essential data which leads to a change in the patient's management and/or ultimate vocal outcome.
The Endogenous Polysaccharide Utilization Rate of Mixed Ruminal Bacteria and the Effect of Energy Starvation on Ruminal Fermentation Rates

When mixed ruminal bacteria were starved in vitro for 24 h, cellular ATP decreased, but there was little change in cell protein. Starved ruminal bacteria derived most of their ATP from cellular polysaccharide. Because polysaccharide declined at a first-order rate of 23%/h, it was possible to estimate the endogenous polysaccharide utilization rate at various stages of starvation by multiplying the amount of utilizable polysaccharide remaining at each time point by 0.23. The bacteria initially had a rate of soluble carbohydrate fermentation that was >717 µg of hexose equivalent/mg of protein per h. Starvation had little impact on the rate of soluble carbohydrate fermentation until 8 to 12 h, and the endogenous polysaccharide utilization rate was <10 mg of hexose/mg of protein per h. The bacteria digested ball-milled cellulose at a rate of 24 µg of hexose/mg of protein per h for 8 to 12 h. Even bacteria that had been starved for 24 h fermented cellulose at a rate of 16 µg of hexose/mg of protein per h. The rate of methane production was initially 70 nmol of methane/mg of protein per min. Short periods of starvation (<12 h) had little impact on methane production, but longer times caused an almost complete inhibition of methanogenesis. The rate of amino acid deamination was initially 31 nmol of ammonia/mg of protein per min, and the critical phase of starvation was again 8 to 12 h. Ruminal bacteria that were harvested at 24 h after feeding had 10-fold less polysaccharide than did bacteria that were harvested at 2 h after feeding, but this polysaccharide supported high rates of soluble carbohydrate and cellulose fermentation, deamination, and methane production.
Group I metabotropic glutamate receptor-dependent TRPC channel trafficking in hippocampal neurons.

The group I metabotropic glutamate receptor agonist (S)-3,5-dihydroxyphenylglycine (DHPG) elicited two phases of synchronized neuronal (epileptiform) discharges in hippocampal slices: an initial phase of short duration discharges followed by a phase of prolonged discharges. We assessed the involvement of transient receptor potential canonical (TRPC) channels in these responses. Pre-treatment of hippocampal slices with TRPC channel blockers, 1-[beta-[3-(4-methoxyphenyl)propoxy]-4-methoxyphenethyl]-1H-imidazole hydrochloride (SKF96365) or 2-aminoethoxydiphenyl borate, did not affect the short epileptiform discharges but blocked the prolonged epileptiform discharges. SKF96365 suppressed ongoing DHPG-induced prolonged epileptiform discharges. Western blot analysis showed that the total TRPC4 or TRPC5 proteins in hippocampal slices were unchanged following DHPG. DHPG increased TRPC4 and TRPC5 in the cytoplasmic compartment and decreased these proteins in the plasma membrane. Translocation of TRPC4 and TRPC5 was suppressed when the epileptiform discharges were blocked by ionotropic glutamate receptor blockers. Translocation of TRPC4 and TRPC5 was also prevented in slices from phospholipase C (PLC) β1 knockout mice, even when synchronized discharges were elicited by the convulsant 4-aminopyridine. The results suggest that TRPC channels are involved in generating DHPG-induced prolonged epileptiform discharges. This function of TRPC channels is associated with a neuronal activity- and PLCβ1-dependent translocation of TRPC4 and TRPC5 proteins from the plasmalemma to the cytoplasmic compartment.
Parental origin of a ring 13 chromosome in a female with multiple anomalies.

A ring chromosome No. 13 was found in a 21-year-old female with multiple anomalies suggestive of 13q-syndrome. Chromosomes of the girl and her parents, studied by quinacrine staining, revealed the ring to be of paternal origin. Detailed study of the quinacrine banding pattern of the ring indicated loss of the most distal band of the long arm (13q34) and possible partial loss of the next adjacent long arm band (13q33). The short arm (13q11) was present but the stalk (13p12) and satellite (13p13) regions appeared to be missing.
Comparative evaluation of decalcified and non-decalcified freeze-dried bone allografts in rhesus monkeys. I. Histologic findings.

Background: Controversy exists regarding the relative merits of decalcified (DFDBA) and non-decalcified (FDBA) freeze-dried bone allografts when used in periodontal or other oral surgical procedures. Methods: Under typical sedation, six rhesus monkeys had nylon mesh cylinders containing either DFDBA or FDBA implanted into surgically created vertical grooves on the facial aspects of all posterior quadrants. Each quadrant received three cylinders containing one type of bone, plus one empty cylinder (E) as negative control, and the full thickness flaps were closed to completely cover the cylinders. Cylinders were retrieved at 1, 2, and 3 months and processed for histologic evaluation. Photomicrographs taken at 8x were randomly evaluated using a histometric grid point counting technique for new bone and old bone within the chambers, and the data were analyzed with analysis of variance plus post-tests. Results: The nylon chambers and their contents were well-tolerated by the tissues. FDBA chambers contained mo...
Comparison of the Metabolism of Retinol Delivered to Human Keratinocytes either Bound to Serum Retinol-Binding Protein or Added Directly to the Culture Medium☆

Abstract Retinol (vitamin A) circulates in the blood bound to retinol-binding protein (RBP), which is thought to be responsible for the delivery of the vitamin to target cells, including the basal cells of the skin (keratinocytes). The process by which keratinocytes acquire retinol from RBP remains controversial. A mechanism for retinol delivery to keratinocytes involving cell surface RBP receptors has been proposed, while other studies support an RBP receptor-independent process. To further explore retinol uptake we have used a model system of human foreskin keratinocytes cultured in serum-free media to compare the metabolism of [ 3 H]retinol delivered to the cells either bound to RBP or added directly to the culture medium. The majority of the cell-associated radioactivity found in keratinocytes incubated for 0.5 to 24 h with either free or RBP bound [ 3 H]retinol was present as [ 3 H]retinyl ester irrespective of the mode of delivery. In keratinocytes incubated for 24 h with [ 3 H]retinol added directly to the culture medium or bound to RBP, [ 3 H]retinyl ester comprised 76 and 80%, respectively, of the total cell-associated radioactivity. Also, the relative cellular levels of the different retinyl esters species synthesized by the keratinocytes were the same whether the [ 3 H]retinol was delivered free or bound to RBP. Finally, the kinetics of loss (turnover) of cell-associated [ 3 H]retinol and [ 3 H]retinyl esters from keratinocytes prelabeled with [ 3 H]retinol delivered free or bound to RBP was the same. Overall, this study demonstrates that the rate and extent of retinol esterification by keratinocytes and the types of esters synthesized are the same whether the vitamin is delivered to the cells free or bound to RBP and argues against RBP receptor-mediated delivery of retinol to specific sites on the plasma membrane that influence overall retinol metabolism.
The Log-Rank conjecture and low degree polynomials

We formulate several questions concerning the intersections of sets of Boolean roots of low degree polynomials. Two of these questions we show to be equivalent to the Log-Rank Conjecture from communication complexity. We further exhibit a slightly stronger formulation which we prove to be false, and a weaker formulation which we prove to be true. These results suggest a possible new approach to the Log-Rank Conjecture.
Is a Picture Worth a Thousand Words? Investigating Structural Knowledge with Textual and Pictorial Stimuli

The differences between the processing of textual and pictorial information have been a topic of research for some time now. Previous research concerning the modality of information has often concentrated on the speed of processing rather than the organizational differences that may exist. This experiment utilized card sorting to evaluate the changes in knowledge organization that occur when information is presented in text and picture formats. In addition to this, the structure of the elicitation task was manipulated to evaluate its effects on sharedness. It was found that textual stimuli produced a greater sharedness among participants in a free sorting task. However, for a structured sorting task, results reversed, and pictorial stimuli created a greater level of sharedness. Overall, structured sorting tasks produced a greater level of sharedness than the free sorting condition, regardless of modality.
Absence of c-fos induction in neonatal rat brain after seizures

Induction of the proto-oncogene c-fos is often considered to be a marker of increased neuronal activity. We have used in situ hybridization to study the pattern of c-fos expression in limbic structures following kainic acid-induced seizures during the postnatal period in the rat. Prior to postnatal day 13 (P13), seizure activity did not result in c-fos induction in any limbic structure. Between P13 and P25, a gradual increase in c-fos expression was observed in hippocampus and cortical structures. These results were corroborated by nuclear run-off transcription assay. Thus, alterations in c-fos transcription that may facilitate stimulus-transcription coupling occur during postnatal development. The possible relationship between the postnatal maturation of c-fos expression and the increase in susceptibility of specific neuronal populations to seizure-induced cell damage is discussed.
Mesoporous Silica Nanoparticles for Cancer Therapy: Energy-Dependent Cellular Uptake and Delivery of Paclitaxel to Cancer Cells.

Biocompatible mesoporous silica nanoparticles, containing the fluorescence dye fluorescein isothiocyanate (FITC), provide a promising system to deliver hydrophobic anticancer drugs to cancer cells. In this study, we investigated the mechanism of uptake of fluorescent mesoporous silica nanoparticles (FMSN) by cancer cells. Incubation with FMSN at different temperatures showed that the uptake was higher at 37°C than at 4°C. Metabolic inhibitors impeded uptake of FMSN into cells. The inhibition of FMSN uptake by nocodazole treatment suggests that microtubule functions are required. We also report utilization of mesoporous silica nanoparticles to deliver a hydrophobic anticancer drug paclitaxel to PANC-1 cancer cells and to induce inhibition of proliferation. Mesoporous silica nanoparticles may provide a valuable vehicle to deliver hydrophobic anticancer drugs to human cancer cells.
The Dead Donor Rule: How Much Does the Public Care. .. And How Much Should We Care?

In this brief commentary, we reflect on the recent study by Siminoff, Burant, and Youngner of public attitudes toward "brain death" and organ donation, focusing on the implications of their findings for the rules governing from whom organs can be obtained. Although the data suggest that many seem to view "brain death" as "as good as death" rather than "dead" (calling the dead donor rule into question), we find that the study most clearly demonstrates that understanding an individual's definition of death is neither a straightforward task nor a good predictor of views about donation. Reflecting on the implications for ongoing debates over the dead donor rule, we suggest that perhaps it is not a change in policy that is warranted, but rather a change in the priorities that have garnered such intense focus on this issue within the field of bioethics.
Visible and infrared obscuration effects of ice fog

Abstract Ice fog is a phenomenon which causes severe obscuration effects at visible and infrared wavelengths in areas where there is a source of water vapor and the ambient temperature falls below −30°C. In this report, Mie scattering calculations have been used to simulate ice fog obscurations and to derive relationships between extinction at these wavelengths. The results are used to compare the extent of the obscuration by ice fog at various wavelengths. Visible wavelengths are found to be less obscured than 1.06, 3.5–5.0, and 11.5–12.0 μm and more obscured than 3.0 and 8–11 μm.
Convenient Estimation of Soil Organic-N Using the Udy Dye System

Abstract A method was developed for conveniently estimating organic‐N in soils using Udy dye, which is bound on the positive sites of the soil organic matter complex. The quantity bound is associated with the quantity of organic‐N. These amounts can be determined by initially adding an excess of dye and, after equilibrium, colorimetrically measuring the amount remaining in solution. A soil pretreatment wash with water and oxalic acid is used to remove soil solution coloration, buffer the soil pH, and precipitate soluble soil calcium. High amounts of soil free iron oxides or carbonates interfered with the test.
Electrochemical behavior of tartaric acid at solid electrodes in aqueous and mixed solutions

Electrochemical behavior of D-tartaric acid at the Pt-, Cu-, Ta-, Cu-Hg-electrodes and the Cd-alloys with Sn, Ni, Hg, and In in aqueous and mixed solutions (water mixtures with acetone, ethanol, dimethylformamide, and pyridine) is studied by voltammetry. It is shown that the tartaric acid voltammograms always show waves related to the hydrogen ion discharge. A method recently suggested by authors allowed calculating the dissociation degrees at different stages, the concentrations of ionized and not ionized forms in dilute solutions of stereoisomers: DL-tartaric, L-tartaric, D-tartaric, and meso-tartaric acids. Simple empiric equations are suggested for the approximate calculating of some dissociation parameters for these acids.
Endoscopic resection of an obstructing antral web in an infant

An antral web was discovered during the work-up of postcibal vomiting in an 18-month-old infant. An omphalocele repair had been performed previously and altered intraperitoneal anatomic relationships favored an endoscopic approach to web resection. The method devised was successful in removing the web; however, six weeks later laparotomy was necessary because of recurrent vomiting. At surgery the web was completely gone, although a circumferential ulcer was now present at the site of the prior web. Antroplasty was curative. An endosopic approach to antral webs is feasible and may in certain cases obviate laparotomy.
Strange goings on in the chiral quark model

Abstract There is some evidence for non-zero strange matrix elements in the proton, if one combines experimental results and SU(3) symmetry. In the quark model, the hyperon masses depend nonlinearly on the strange quark current mass m s , and so the standard calculation of 〈p∥ss∥p〉 is untrustworthy. The ss matrix element can be calculated in the chiral quark model, and the result agrees with the standard calculation. The threshold for kaon condensation is also calculated.
Aurintricarboxylic acid modulates the affinity of hepatitis C virus NS3 helicase for both nucleic acid and ATP.

Aurintricarboxylic acid (ATA) is a potent inhibitor of many enzymes needed for cell and virus replication, such as polymerases, helicases, nucleases, and topoisomerases. This study examines how ATA interacts with the helicase encoded by the hepatitis C virus (HCV) to reveal that ATA interferes with both nucleic acid and ATP binding to the enzyme. We show that ATA directly binds HCV helicase to prevent the enzyme from interacting with nucleic acids and to modulate the affinity of HCV helicase for ATP, the fuel for helicase action. Amino acid substitutions in the helicase DNA binding cleft or its ATP binding site alter the ability of ATA to disrupt helicase-DNA interactions. These data, along with molecular modeling results, support the notion that an ATA polymer binds between Arg467 and Glu493 to prevent the helicase from binding either ATP or nucleic acids. We also characterize how ATA affects the kinetics of helicase-catalyzed ATP hydrolysis, and thermodynamic parameters describing the direct interaction between HCV helicase and ATA using microcalorimetry. The thermodynamics of ATA binding to HCV helicase reveal that ATA binding does not mimic nucleic acid binding in that ATA binding is driven by a smaller enthalpy change and an increase in entropy.
Lateral inhibition: inherent recurrent processes in coherent optical propagation

Processes that are analogous to the neural process of recurrent lateral inhibition can be found in optical systems that consist of a shift-invariant system and a Fabry-Perot cavity. The properties of the optical recurrent system are derived and demonstrated by computer simulation. The simulation shows that optical lateral inhibition can be used to enhance the outline of an amplitude object and to make phase-only objects directly detectable and visible. The optical recurrent system is compared with frequency-plane spatial filtering. Requirements and practical limitations for the design of an optical recurrent system are also discussed.