cssi/SciSciGPT-SciSciNet huggingface dataset:
2D NMR of paramagnetic metalloenzymes: cyanide-inhibited horseradish peroxidase.

Two-dimensional (2D) proton NMR correlation spectroscopy, COSY, and nuclear Overhauser spectroscopy, NOESY, have been used to explore the applicability of these methods for the moderately large (42 KDa), paramagnetic cyanide-inhibited derivative of horseradish peroxidase, HRP-CN. The target resonances are those in the active site of HRP-CN which experience substantial hyperfine shifts and paramagnetic relaxation. The magnitude COSY experiment was found to yield cross peaks for all known spin-coupled heme substituents, as well as for the majority of non-heme hyperfine shifted protons, in spite of line widths of the order of ∼100 Hz. Moreover, the rapid relaxation of the hyperfine-shifted resonances allows the extremely rapid collection of useful 2D NMR data sets without the loss of information. For the heme, the combination of COSY cross peaks for the vinyl and propionate substituents, and NOESY cross peaks among these substituent protons and heme methyls, allows assignment of heme resonances without recourse to deuterium labeling of the heme. A seven-proton coupled spin system was identified in the upfield region that is consistent with originating from the proposed catalytic Arg38 residue in the distal heme pocket, with orientation relative to the heme similar to that found in cytochromec peroxidase. The upfield hyperfine-shifted methyl group in the substrate binding pocket previously proposed to arise from Leu237 is shown to arise instead from an as yet unidentified Ile. NOESY spectra collected at very short (3 ms) and intermediate (20 ms) mixing times indicate that build-up curves can be obtained that should yield estimates of distances in the heme cavity. It is concluded that 2D NMR studies should be able to provide the heme assignments, aid in identifying the catalytic residues, and provide information on the spatial disposition of such residues in the active site for cyanide complexes of a number of intermediate to large paramagnetic heme peroxidases, as well as for other paramagnetic metalloenzymes with line widths of ∼ 100 Hz. Moreover, paramagnetic-induced hyperfine shifts and linewidths to ∼100 Hz need not interfere with the complete solution structure determination of a small paramagnetic protein solely on the basis of 2D NMR data.
Metabolic fate of chemical mixtures. I. "Shuttle Oxidant" effect of lipoxygenase-generated radical of chlorpromazine and related phenothiazines on the oxidation of benzidine and other xenobiotics.

Many carcinogens, mutagens, teratogens, and other toxicants are known to be oxidized by lipoxygenases to potentially deleterious free radical intermediates. In this study, we tested for the first time the possibility that certain efficient substrates for lipoxygenase produce shuttle oxidants that stimulate the generation of reactive species from other chemicals. To evaluate the hypothesis, we investigated the metabolic interaction of two well-known substrates, chlorpromazine and benzidine, which have been shown to be oxidized by soybean lipoxygenase in the presence of hydrogen peroxide. The evidence presented here clearly indicates that the chlorpromazine cation radical generated by the lipoxygenase triggers a rapid oxidation of benzidine to benzidine diimine. Under the experimental conditions employed, the metabolic interaction resulted in a 42-fold stimulation in the rate of benzidine oxidation. The magnitude of stimulation of benzidine oxidation exhibited a dependence on the pH of the reaction medium, amount of the enzyme, and concentration of chlorpromazine, benzidine, and hydrogen peroxide. A number of other phenothiazines were also found to stimulate benzidine oxidation, albeit to a lesser degree. The chlorpromazine cation radical stimulated the oxidation of all six other xenobiotics tested. The highest stimulation (94-fold) was noted with tetramethyl phenylenediamine oxidation to the Wursters blue radical, while the lowest stimulatory response (2-fold) was observed with guaiacol. Preliminary data suggest that purified human term placental lipoxygenase also displays a similar stimulatory response in the benzidine oxidation in the presence of chlorpromazine. Although the toxicological significance of these in vitro findings remains to be established, it is worth pondering whether such a synergistic interaction occurs in humans in vivo. Teratogenesis Carcinog. Mutagen. 20:195-208, 2000.
Catheter and Surgical Treatment of Cardiac Arrhythmias

Over the past decade, numerous impressive advances have been made using nonpharmacologic methods for control of cardiac arrhythmias. These methods include surgical or catheter ablation of abnormal foci. Current techniques involve catheter ablation of the atrioventricular junction to control supraventricular arrhythmias. In addition, surgical techniques have proved to be remarkably safe and effective for treatment of patients with accessory pathways and those with atrioventricular nodal reentrant tachycardia. Patients with drug-refractory ventricular tachycardia may benefit from surgical resection of the ventricular tachycardia focus. The use of these interventional methodologies has radically altered the approach to management of patients with drug-refractory cardiac arrhythmias. (JAMA. 1990;263:79-82)
Habitat mediates the outcome of a cleaning symbiosis for a facultatively burrowing crayfish

Summary Branchiobdellidans are small, symbiotic annelids (Clitellata) that can have positive effects on the survival and growth of the crayfish host. We hypothesised that branchiobdellidans would be particularly beneficial to crayfish that move to underground burrows (characterised by poor water quality) as surface waters recede. In surface water mesocosms, the symbioses were mutualistic, with worm (Cambarincola barbarae.) density increasing over time and crayfish (Procambarus clarkii) growing faster when worms were present. Contrary to previous studies, the outcome did not shift from mutualism to parasitism at high worm densities. In burrowing chambers in the laboratory, the symbiotic relationship was lost, as worm density decreased by 92% and crayfish growth ceased. Similarly, in burrows excavated in field experiments, worm density decreased by 84%. Rather than the symbiotic relationship increasing survival when crayfish moved underground, this crayfish species may be faced with a trade-off between the benefits of a mutualism with worms while on the surface and protection from heat stress and desiccation by burrowing when water levels are low.
The "ICE" study: feasibility of inexpensive commercial coolers on mobile EMS units.

Introduction Prehospital postresuscitation induced hypothermia (IH) has been shown to reduce neurological complications in comatose cardiac-arrest survivors. Retrofitting ambulances to include equipment appropriate to initiate hypothermia, such as refrigeration units for cooled saline, is expensive. The objective of this nonhuman subject research study was to determine if inexpensive, commercially available coolers could, in conjunction with five reusable ice packs, keep two 1 L bags of precooled 0.9% normal saline solution (NSS) at or below 4°C for an average shift of eight to 12 hours in a real-world environment, on board in-service Emergency Medical Service (EMS) units, over varying weather conditions in all seasons. Methods The coolers were chosen based on availability and affordability from two nationally available brands: The Igloo MaxxCold (Igloo Products Corp., Katy, Texas USA) and Coleman (The Coleman Company, Wichita, Kansas USA). Both are 8.5 liter (nine-quart) coolers that were chosen because they adequately held two 1 L bags of saline solution, along with the reusable ice packs designated in the study design, and were small enough for ease of placement on ambulances. Initial testing of the coolers was conducted in a controlled environment. Thereafter, each EMS unit was responsible to cool the saline to less than 4°C prior to shift. Data were collected by emergency medical technicians, paramedics, and resident physicians working in seven different ambulance squads. Data analysis was performed using repeated measurements recorded over a 12-hour period from 19 individual coolers and were summarized by individual time points using descriptive statistics. Results Initial testing determined that the coolers maintained temperatures of 4°C for 12 hours in a controlled environment. On the ambulances, results based on the repeated measurements over time revealed that the saline solution samples as defined in the protocol, remained consistently below 4°C for 12 hours. Utilizing the lower bound of the 2-sided 95% exact binomial confidence intervals, there was less than a five percent chance that saline samples could not be maintained below 4°C for 12 hours, even during the summer months. Conclusions Simple, commercially available coolers can maintain two 1 L bags of 0.9% NSS at 4°C for 12 hours in ambulances in varying environmental conditions. This suggests that EMS agencies could inexpensively initiate prehospital IH in appropriate cases. Kane KE , Tomsho RJ , Pheasant K , Stauffer T , Schoenfeldt B , Hamilton S , Kain T , Kane BG . The “ICE” Study: Feasibility of Inexpensive Commercial Coolers on Mobile EMS Units. Prehosp Disaster Med. 2014;29(3):1-8 .
Polymeric drug delivery systems for treatment of cardiovascular calcification, arrhythmias and restenosis

Abstract Cardiovascular controlled release, utilizing drug-polymer composites implanted in direct contact with the heart, has recently come into clinical use with a dexamethasone eluting cardiac pacemaker lead tip. Furthermore, cardiovascular controlled release systems are under active investigation in a number of other areas of possible application. The general working hypothesis of this approach is that regionally administered drug delivered directly to the heart or a blood vessel will more efficiently and effectively treat localized disease processes of interest, while avoiding systemic side effects. Successful experimental examples illustrating the validity of this hypothesis have involved investigations into cardiovascular calcification, therapy of cardiac arrhythmias, and treatment of arterial restenosis following angioplasty. Efficacious results in each of these areas, with some limitations, have been noted, and are discussed in detail in this paper. An ideal cardiovascular controlled release system will consist of a feedback responsive implant in which drug release kinetics could be varied according to disease activity, or other considerations such as side effects of the therapeutic agent. Furthermore, cardiovascular drug delivery should be ideally extremely long acting and this may be possible through the use of therapeutic agents in a refillable reservoir configuration, or local gene therapy with long standing expression of the gene of interest.
Case Files of the New York City Poison Control Center: Paradichlorobenzene-Induced Leukoencephalopathy

Keywords Ataxia.Encephalopathy.Leukoencephalopathy.Moth ball(s).Paradichlorobenzene.White matter diseaseCase PresentationA 44-year-old man was brought to the emergency depart-mentbyemergencymedicalservicesafterhewasdiscoveredlying supine on his apartment floor. He was accompanied byhissister,whohaddecidedtovisithimafterhisabsencefroma family function. Worsening “bizarre” behavior had beennoted by family members for 4 weeks, characterized byanorexia, social withdrawal, flat affect, and alogia. Prior tohis illness, he was described as functional, independent,gainfully employed, and social.The patient had mild mental retardation and hyperten-sion. There was no history of diagnosed psychiatric illness,although his family suspected pica. Medications includedan unknown antihypertensive with which he was notcompliant. He occasionally used marijuana and alcohol,without history of other abused drugs. The patient’s sisterreported significant weight loss over several months.There had been no apparent fevers, cough, vomiting,diarrhea, or convulsions. On physical examination, heappeared drowsy, was markedly cachectic, and emanatedan atypical aromatic body odor. Initial vital signs were:blood pressure 154/90 mmHg, heart rate 98/min, respira-tory rate 20/min, rectal temperature 37.4°C, and room airoxygen saturation 97%. Head, neck, chest, and abdominalexaminations were unremarkable. He had dry, scaling, andichthyotic skin. He was oriented to person and place, butnot to time, date, or indication for hospitalization. Limitedcranial nerve evaluation was normal. Pain and light-touchsensation were unaffected. Hyperreflexia (without clonus)and cogwheel rigidity were noted in both lower extrem-ities; upper extremities were normal. Plantar reflexes werenormal bilaterally. Muscle bulk, tone, and strength werenormal. The patient was unable to stand without supportand unable to ambulate, apparently due to impairedequilibrioception. He could follow simple one-step com-mands. He would speak a few words when asked simplequestions, and he avoided eye contact.Serum electrolytes (sodium, potassium, chloride, calcium,and magnesium) and serum glucose were normal. Tests ofhepatic and renal function were: AST 53 U/l (0–40 U/l), ALT25U/l(10–40U/l),alkalinephosphatase88U/l(35–145U/l),total bilirubin 6.84 μmol/l (0.4 mg/dl) (0–20.52 μmol/l; 0–1.2 mg/dl), ammonia 31 μmol/l (43.42 μg/dl) (11–35 μmol/l;
Evaluation and QTL mapping of resistance to powdery mildew in lettuce

Lettuce (Lactuca sativa) is the major leafy vegetable that is susceptible to powdery mildew disease under greenhouse and field conditions. Quantitative trait loci (QTLs) for resistance to powdery mildew under greenhouse conditions were mapped in an interspecific population derived from a cross between susceptible L. sativa cultivar Salinas and the highly susceptible L. serriola accession UC96US23. Four significant QTLs were detected on linkage groups LG 1 (pm-1.1), LG 2( pm-2.1 and pm-2.2) and LG 7 (pm-7.1), each explaining between 35 to 42% of the phenotypic variation. The four QTLs are not located in the documented hotspots of lettuce resistance genes. Alleles for the disease resistance at the four QTLs originated from both parents (two from each), demonstrating that even highly susceptible accessions may provide alleles for resistance to powdery mildew. These QTLs appeared to operate during limited periods of time. Results of the field trials with F2:3 and F3:4 families derived from a Soraya (moderately resistant) 9 Salinas cross demonstrated effective transfer of resistance to powdery mildew in this material. An integrated rating approach was used to estimate relative levels of resistance in 80 cultivars and accessions tested in a total of 23 field and greenhouse experiments. Generally, very low resistance was observed in crisphead-type lettuces, while the highest relative resistance was recorded in leaf and butterhead types. Comparison of two disease assessment methods (percentage rating and the area under the disease progress steps, AUDPS) for detection of QTLs shows that the two approaches complement each other.
UNDERSTORY SPECIES PATTERNS AND DIVERSITY IN OLD-GROWTH AND MANAGED NORTHERN HARDWOOD FORESTS

Forest management can significantly affect both the diversity and spatial patterning of understory vegetation. However, few studies have considered both diversity and spatial patterning at a stand scale. Our objective was to evaluate the effects of forest management on understory plant communities in northern hardwood forests and assess the processes governing differences in species composition, diversity, and spatial patterns. We sampled understory vegetation (all species ,2 m tall) and percentage of light transmission levels in three forest types in 12 mesic northern hardwood stands in northern Wisconsin and the Upper Peninsula of Michigan, USA: old-growth, undisturbed forests; even-aged forests resulting from clearcut logging (;65-85 yr old); and uneven-aged forests with recent selective logging. Estimated understory species richness per stand, mean species richness per quadrat, and mean percent cover per quadrat were lower in old-growth forest than in even-aged, second- growth forests and lower in even-aged than in uneven-aged, second-growth forests. Dif- ferences in species composition among the three forest types were related to available light and to coarse woody debris; however, differences between the cover of most plant groups were not significant. The mean patch size of species diversity and cover is highly variable and could not be related to forest stand type. However, understory communities in old- growth forests have significantly smaller community patch sizes and larger compositional heterogeneity. Community patch size is correlated with both coarse woody debris and light heterogeneity. Each forest stand type produces a characteristic combination of understory composition, diversity, and spatial patterning of communities. Although harvesting has negligible effects on understory alpha diversity in these mesic hardwood forests, spatial structure is slower to recover and has not recovered in the even- and uneven-aged northern hardwood forests studied. If management objectives include preserving or restoring the ecological character of the forest, harvesting may need to be altered or delayed predicated on the character of the understory.
Production of polymorphic sperm by anopheline mosquitoes and their fate within the female genital tract

The males of two mosquito species within the Anopheles gambiae complex, An. gambiae s.s. and An. quadriannulatus, as well as males of An. darlingi, produced sperm of significantly varying lengths, while a sperm polymorphism was absent in Aedes aegypti and other anophelines not suspected of belonging to species complexes. The polymorphic distribution of these sperm lengths was not significantly different in smaller adult males that were reared on a low larval diet. The reproductive tract of the female was more likely to contain larger sperm, but overall sperm retention varied depending on the size of the female and the volume of the spermatheca she contained. The presence of a sperm polymorphism may be a factor that has promoted speciation, as well as providing an indication that females may mate multiply.
Quantitative determination of hyoscyamine and scopolamine by direct photodensitometry of thin-layer chromatograms

A rapid and simple method for the quantitative evaluation of thin-layer chromatograms of hyoscyamine and scopolamine by direct photodensitometry was investigated. Excellent separation with discrete spots for the two alkaloids was quickly obtained using absolute methanol-ammonia T.S. (200:1 v/v) as the developing solvent. Spots were made visible by spraying with Munier and Macheboeuf's modification of Dragendorff's reagent. Linear standard curves were obtained for each alkaloid when the integrated function of the size and density of the spot was correlated with micrograms of alkaloid applied. The upper and lower limits of the standard curves were 4 to 65 meg. for hyoscyamine, and 7 to 60 meg. for scopolamine. The optimal range for both alkaloids was approximately 20 to 30 meg. Pure alkaloids and plant extracts were determined by photodensitometric and spectrophotometric methods, and results were compared.
Plume tectonics as a cause of mass wasting on the southeast Greenland continental margin

Deposition of sediments on the southeast Greenland shelf is limited by its narrow width, low degrees of tectonic subsidence, and lack of a block faulted basement topography. A marked hiatus on the continental slope, removing the Eocene and Oligocene, together with a late Eocene-early Oligocene hiatus on the continental rise, can be related to mass wasting along the continental slope. Erosion correlates with a phase of rapid tectonic subsidence, caused by relative retreat of the Iceland Plume from the area, affecting the oceanic crust more than the continental shelf. Relative deepening of > 1 km over 10 my steepened the continental slope and triggered erosion. Following the cessation of rapid subsidence, a submarine fan progressively onlapped the continental slope. The lack of a major mid Oligocene erosion surface on the shelf, despite shallow water depths, indicates that the magnitude of the mid Oligocene eustatic sea level fall is much less than the 200m predicted by the Exxon sea level curve.
Mobile health applications: The patchwork of legal and liability issues suggests strategies to improve oversight

Mobile health (mHealth) technology has facilitated the transition of care beyond the traditional hospital setting to the homes of patients. Yet few studies have evaluated the legal implications of the expansion of mHealth applications, or “apps.” Such apps are affected by a patchwork of policies related to medical licensure, privacy and security protection, and malpractice liability. For example, the privacy protections of the Health Insurance Portability and Accountability Act (HIPAA) of 1996 may apply to only some uses of the apps. Similarly, it is not clear what a doctor’s malpractice liability would be if he or she injured a patient as the result of inaccurate information supplied by the patient’s self-monitoring health app. This article examines the legal issues related to the oversight of health apps, discusses current federal regulations, and suggests strategies to improve the oversight of these apps.
Diphosphine is an intermediate in the photolysis of phosphine to phosphorus and hydrogen

The photolysis of phosphine to red phosphorus (P4) and hydrogen is investigated in light of the potential significance of the reaction in the atmospheric chemistry of Jupiter. It is reported that the photolysis of PH3 at room temperature by a 206.2-nm light source gave rise to a product identified by its UV and IR spectra and gas chromatographic retention time as P2H4, the yield of which is found to increase to a maximum and then decrease to 20% of the maximum value with illumination time. A mechanism for phosphine photolysis including diphosphine formation as an intermediate step is proposed, and it is concluded that P2H4 is a likely constituent of the atmospheres of the Jovian planets.
Social context and psychosocial influences on blood pressure among American Samoans

This study explores social and explores social and economic influences on health within a model formulated to address explicitly both individual and household level phenomena. Dressler's lifestyle incongruity model is used as a basis from which to predict the effects of intracultural contexts of variability on blood pressure. The sample for this survey consists of 134 Samoan men and women living in American Samoa. Based on previous experience and ethnographic sources, two key intracultural contexts were examined; gender, i.e., male-female differences in response to psychosocial stress, and household employment as indicated by whether or not both spouses in a household are employed. Our analysis indicates that lifestyle incongruity, defined as the difference between the material culture presented by a household and the economic resources of the family, is significantly associated with both systolic and diastolic blood pressure. Furthermore, males and females show opposite blood pressure associations with both lifestyle incongruity (male blood pressure increases with increasing incongruity while female blood pressure does not) and household employment (male blood pressure is higher when both spouses work but female blood pressure is lower).
Fabry's disease (ceramide trihexosidase deficiency): diagnostic confirmation by analysis of dental pulp.

Abstract Six neutral glycosphingolipids were identified in dental pulp from normal individuals and hemizygotes and heterozygotes for Fabry's disease by biochemical analysis. Histochemical stains were selected to demonstrate the presence of glycosphingolipid. Only small amounts of glycosphingolipid material could be detected in normal pulp or in pulp from heterozygotes for Fabry's disease by histochemical or biochemical techniques. However, the pulp from a hemizygote demonstrated a marked deposition of PAS positive material and a specific increase of trihexosyl ceramide, the glycosphingolipid which accumulates in this disorder. These procedures provide a reliaable method for the diagnostic confirmation of hemizygotes with Fabry's disease.
First-principles calculation of H vibrational excitations at a dislocation core of Pd

Palladium is an ideal system for understanding the behavior of hydrogen in metals. In Pd, H is located both in octahedral sites and in dislocation cores, which act as nanoscale H traps and form Cottrell atmospheres. Adjacent to a dislocation core, H experiences the largest possible distortion in alpha-Pd. Ab initio density-functional theory computes the potential energy for a hydrogen in an octahedral site in alpha-Pd and in a trap site at the core of a partial of an edge dislocation. The Pd partial dislocation core changes the environment for H, distorting the H-Pd bonding which changes the local potential, vibrational spectra, and inelastic form factor for an isolated H atom. The decrease in excitation energy is consistent with experiments, and the calculations predict distortions to the H wavefunction.
Impact of larval Dorosoma predation on Daphnia parvula dynamics

SUMMARY 1 In reservoirs of the south-eastern United States, Daphnia typically decline in abundance during the summer months. Current understanding suggests that adult shad (Dorosoma spp.), the dominant planktivore in these reservoirs, plays a limited role in Daphnia midsummer declines. The impact of shad larvae is beginning to be documented. 2 To examine the impact of larval shad on Daphnia seasonal dynamics, larval dynamics were studied over two seasons and stomach contents were analysed during one season. 3 Initial Daphnia panwla declines correlated with abundance of shad larvae. During the decline, shad stomach contents consisted of 97—100%D. parvula. After D. parvula declined, Bosmina and Diaphanosoma accounted for up to 97% of larval diets. When shad diets included other cladocerans, D. parvula abundance increased in the reservoir. 4 When this predation pattern was incorporated into a predictive model, larval shad predation accounted for an initial, temporary decline in D. parvula abundance. However, when other crustaceans were incorporated into the shad diet, D. parvula populations increased. 5 These results suggest that larval shad have a temporary, strong influence on the structure and abundance of D. parvula populations in south-eastern reservoirs of the United States.
Geophysical study of the northwest African margin off Morocco

Abstract Six geophysical profiles were taken over the northwestern African margin between the Canary Islands and Morocco. A magnetic smooth zone occupies the upper continental rise landward of lineated sea-floor spreading anomalies of Late Jurassic to Early Cretaceous age. This smooth zone is believed due in part to a Late Jurassic uniform polarity interval; its seaward boundary is correlated with a basement high and/or abrupt landward thickening of sediments. Spreading may have started over 200 × 10 6 yr ago at a rate of 0·55 cm/yr and accelerated 150 to 160 × 10 6 yr at the smooth zone boundary. No counterpart of the east coast magnetic slope anomaly was observed off Morocco while the distance between the shelf break and the smooth zone boundary is also less here than off northeastern America. This difference suggests a shift in the position of the accreting plate boundary from west to east, about 200 × 10 6 yr ago, after the formation of the slope anomaly. Gravity data show that the Moroccan margin is largely in isostatic equilibrium, and that the zone of transition from oceanic to continental crustal thickness is wider off the Canaries (400 km) than off Morocco (100–150 km). The sediment section of the seismic reflection profiles includes an upper acoustically transparent unit (usually restricted to the upper rise) a middle stratified unit, and a lower transparent unit. The upper unit is probably pelagic calcareous ooze. Other lithologies are unknown but the stratified unit may in part include an Early Tertiary unconformity. Sections of the shelf and slope exhibit deformation that have probably been caused by the Alpine orogeny.
The Nobel Centennial 1901–2001

The year 2001 marks the 100th anniversary of the awarding of the first Nobel Prizes. This article briefly discusses the life and work of Alfred Bernhard Nobel, his will that instituted the prizes, the Nobel statutes, controversial recipients, neglected chemists, criticisms of the prizes, and the Nobel Centennial Celebrations. The prizes in chemistry and the international nature of the awards are emphasized.
Oogonial stem cells: do they exist and may they have an impact on future fertility treatment?

Purpose of review Germline stem cell research over the last decade has brought into question one of the basic tenets of reproductive biology that women are born with a finite number of oocytes without the potential for renewal. Evidence for the existence of oogonial stem cells in the postnatal ovary has gained momentum, but skepticism remains. Recent findings Several research studies claimed that they have identified functional oogonial stem cells in the postnatal ovary of several different species including humans. The scientific community has questioned both the methods and significance of these studies. Summary Many speculate that germline stem cells could make a significant impact on the treatment of female infertility. However, this field of research is still in its infancy. There is still much to learn about the biology of oogonial stem cells and their potential clinical application. More research is needed before oogonial stem cells can become a viable treatment modality for women with infertility.
Calcein as an Indicator for the Determination of Total Calcium and Magnesium and Calcium Alone in the Same Aliquot of Milk

Summary A method has been developed for calcium and magnesium determination in milk on the basis of the different behavior of these two cations towards the indicator calcein. The determination of both cations can be performed by back titration with calcium chloride solution in the same aliquot of a diluted milk containing an excess of Ethylenediamine tetraacetate (EDTA). Total calcium and magnesium can be obtained in milk at pH range 12.0 to 12.5, whereas calcium alone can be obtained from pH 13.0 to 13.5. Comparison of the values obtained for total calcium and magnesium by the calcein method with those obtained by the Eriochromeblaek T method indicates no significant difference. The recoveries of calcium added to milk are complete. Concentrations of phosphates and proteins four times those present in the average milk and of heavy metals as present in average milk do not influence the results. Variations in the added amount of indicator between 0.05 and 0.15 ml and in the dilution of the sample with water in the ratio from 1:10 to 1:30 do not influence significantly the results. The method is rapid and reproducible, with a standard deviation of ±0.14 meq/liter of milk for total calcium and magnesium, or ±0.19% of the measured value, and ±0.12 meq/liter of milk for calcium alone, or ±0.18% of the calcium content.
Cardiomyocyte-specific perilipin 5 overexpression leads to myocardial steatosis and modest cardiac dysfunction

Presence of ectopic lipid droplets (LDs) in cardiac muscle is associated to lipotoxicity and tissue dysfunction. However, presence of LDs in heart is also observed in physiological conditions, such as when cellular energy needs and energy production from mitochondria fatty acid β-oxidation are high (fasting). This suggests that development of tissue lipotoxicity and dysfunction is not simply due to the presence of LDs in cardiac muscle but due at least in part to alterations in LD function. To examine the function of cardiac LDs, we obtained transgenic mice with heart-specific perilipin 5 (Plin5) overexpression (MHC-Plin5), a member of the perilipin protein family. Hearts from MHC-Plin5 mice expressed at least 4-fold higher levels of plin5 and exhibited a 3.5-fold increase in triglyceride content versus nontransgenic littermates. Chronic cardiac excess of LDs was found to result in mild heart dysfunction with decreased expression of peroxisome proliferator-activated receptor (PPAR)α target genes, decreased mitochondria function, and left ventricular concentric hypertrophia. Lack of more severe heart function complications may have been prevented by a strong increased expression of oxidative-induced genes via NF-E2-related factor 2 antioxidative pathway. Perilipin 5 regulates the formation and stabilization of cardiac LDs, and it promotes cardiac steatosis without major heart function impairment.
Space: the final frontier in the learning of science?

In Space, relations, and the learning of science, Wolff-Michael Roth and Pei-Ling Hsu use ethnomethodology to explore high school interns learning shopwork and shoptalk in a research lab that is located in a world class facility for water quality analysis. Using interaction analysis they identify how spaces, like a research laboratory, can be structured as smart spaces to create a workflow (learning flow) so that shoptalk and shopwork can projectively organize the actions of interns even in new and unfamiliar settings. Using these findings they explore implications for the design of curriculum and learning spaces more broadly. The Forum papers of Erica Blatt and Cassie Quigley complement this analysis. Blatt expands the discussion on space as an active component of learning with an examination of teaching settings, beyond laboratory spaces, as active participants of education. Quigley examines smart spaces as authentic learning spaces while acknowledging how internship experiences all empirical elements of authentic learning including open-ended inquiry and empowerment. In this paper I synthesize these ideas and propose that a narrative structure might better support workflow, student agency and democratic decision making.
Self-efficacy and exercise participation in sedentary adult females.

Abstract Background. This study examined the importance of selected psychosocial and biometric variables in the prediction of exercise behavior in sedentary adult females. Specifically, the relationships among exercise behavior and instructor influence, self-efficacy cognitions, self-motivation, and body composition and their ability to predict exercise participation were evaluated. Methods. Fifty-eight females volunteered to participate in an eight-week aerobic exercise program. Biometric and psychosocial variables were assessed prior to and following the program. Attendance data and activity logs provided participation data. Subjects were also contacted three months after program termination to assess their activity patterns at that time. Results. Multivariate analyses of variance indicated that subjects categorized as high or low in either program or overall exercise participation differed significantly on body weight, efficacy cognitions, and post-program perceptions. Multiple regression analyses indi...
An abundant cytoplasmic 7S RNA is complementary to the dominant interspersed middle repetitive DNA sequence family in the human genome

Evidence is presented that a homogeneous cytoplasmic species known as 7S RNA is the only abundant RNA in uninfected HeLa cells which can form strong hybrids with the dominant family of middle repetitive DNA sequences in the human genome. These DNA sequences are known collectively as the Alu family, because most of them share a common Alu I restriction site. When purified 7S RNA was hybridized to three different genomic clones containing Alu family DNA sequences, a specific region (or regions) comprising at most half the RNA sequence was protected from mild digestion with T1 ribonuclease; moreover, the hybrids between 7S RNA and cloned Alu family DNA wer imperfect, since T1 RNAase was able to nick the protected 7S RNA sequences under conditions where a true RNA: DNA duplex would have been resistant. This suggests that 7S RNA is encoded either by a small subset of the 300,000 Alu family sequences in the human genome or by an entirely different family of genes. The sequence of 7S RNA has been highly conserved through recent evolution, and in both avian and murine cells the RNA is selectively incorporated into oncornavirus particles during productive infection. The cellular function of 7S RNA is unknown.
How do viral infections predispose patients to bacterial infections

Purpose of reviewBacterial sepsis is a leading cause of death in the United States, accounting for over 200 000 fatalities annually. Approximately half of bacterial sepsis cases occur following acute respiratory infections, and the lungs are the most common organs to fail. Notably, outbreaks of resp
Diversion of an intramolecular [2+4] cycloaddition reaction into a [2+2] pathway by electrophilic catalysis

Summary The intramolecular [2+4] cycloaddition process 1 into 2 is diverted to a [2 + 2] process by electrophilic catalysis, 1 into 4 .
Single-molecule resolution of interfacial fibrinogen behavior: effects of oligomer populations and surface chemistry.

Through the use of single-molecule total internal reflection fluorescence microscopy, the dynamic behavior of fibrinogen was observed at the interface between aqueous solution and various solid surfaces. Multiple populations of objects were observed, as characterized by surface residence times, interfacial diffusion, and fluorescence intensity. On all surfaces, populations exhibited direct links between surface residence time, rate of diffusion, and fluorescence intensity. In particular, longer-lived populations diffused more slowly and exhibited greater fluorescence intensity, leading to the conclusion that the objects represented fibrinogen monomers and discrete oligomer populations (dimers, trimers, etc.), and that these oligomer populations play an important role in the protein−surface interaction because of their long surface residence times. Two or three diffusive modes were observed for most populations, indicating that protein aggregates have multiple mechanisms for interaction with solid substrat...
Flow of rarefied gas over an enclosed rotating disk

Es wird gezeigt, dass der Ubergang von der Kontinuumsstromung zur «Gleitstromung» (slip-flow) an einer rotierenden Scheibe durch ihren Abstand von der ruhenden Wand, die Drehgeschwindigkeit und den Gasdruck bestimmt wird. Messungen zeigen, dass die Maxwellsche Grenzbedingung fast bis zur Molekularstromung herab erfullt bleibt. Trotz der Unterschiede zwischen der theoretischen (unendlich ausgedehnten) und der wirklichen Scheibe werden die Reibungskoeffizienten fur beide Falle sehr ahnlich.
Hybrid antibodies can target sites for attack by T cells

It would be advantageous in the case of certain diseases to be able to focus a strong T-cell response at a chosen target, for example, in treating cancer or infections that have escaped the normal host response. At present, it seems inconceivable that we could use antigen-specific lines or clones of effector T cells for this purpose because of complications due to the major histocompatibility restriction of T-cell specificity and the problem of rejection of transplanted effector cells. Here we describe a novel technology which combines the power of T lymphocytes in eliminating unwanted cells and causing beneficial inflammatory reactions with the great advantages of monoclonal antibodies (their specificity and availability). We show that heteroconjugates of monoclonal antibodies (referred to hereafter as hybrid antibodies), in which one of the component binding sites is anti-T-cell receptor and the other component binding site is directed against any chosen target antigen, can focus T cells to act at the targeted site. Monoclonal antibodies directed against the T-cell receptor, such as the anti-allotype used here, are mitogenic for resting T cells and can be used to induce effector T cells carrying the T-cell receptor determinant which can then be directed against the target by a hybrid antibody.
Hematocrit and left ventricular mass: The Framingham Heart study

OBJECTIVES The goal of this study was to investigate the relationship between hematocrit (Hct) and left ventricular mass index (LVMI) and LV hypertrophy (LVH) in subjects without known hypertension or cardiovascular disease in the Framingham Heart study. BACKGROUND Anemia may be an independent risk factor for cardiovascular disease in the general population. One potential explanation for this finding could be an association between Hct with LVMI or LVH. METHODS Linear and logistic regression analyses were used to evaluate the association between Hct with LVMI and LVH. All analyses were stratified by gender and further according to menopausal status in women. RESULTS There were 1,376 men and 1,769 women who met the inclusion criteria. The mean Hct and LVMI were 46.5% and 41.9%, and 127.3 and 95.8 g/m, respectively, in men and women. After adjustment for confounders, each 3% lower Hct was associated with a 2.6 g/m higher mean LVMI in men, and a 1.8 g/m higher mean LVMI in postmenopausal women (p < 0.05). There was a significant quadratic relationship between Hct and LVMI in premenopausal women (p < 0.01). Subjects in the lowest quartile of Hct (compared with the rest of the sample) had an adjusted odds ratio of LVH of 2.0 (95% confidence interval [CI] 1.3 to 3.0) in men and 1.4 (95% CI 0.8 to 2.4) in postmenopausal women. CONCLUSIONS In a sample without known hypertension or cardiovascular disease, a lower Hct is associated with echocardiographically determined LVH in men and a small but significantly higher LVMI in men and postmenopausal women. The clinical importance of these findings remains unknown.
Inexpensive monocular pico-projector-based augmented reality display for surgical microscope

This paper describes an inexpensive pico-projector-based augmented reality (AR) display for a surgical microscope. The system is designed for use with Micron, an active handheld surgical tool that cancels hand tremor of surgeons to improve microsurgical accuracy. Using the AR display, virtual cues can be injected into the microscope view to track the movement of the tip of Micron, show the desired position, and indicate the position error. Cues can be used to maintain high performance by helping the surgeon to avoid drifting out of the workspace of the instrument. Also, boundary information such as the view range of the cameras that record surgical procedures can be displayed to tell surgeons the operation area. Furthermore, numerical, textual, or graphical information can be displayed, showing such things as tool tip depth in the work space and on/off status of the canceling function of Micron.
Influence of gonadal hormones on the behavioral effects of intermittent hypoxia in mice

Obstructive sleep apnea (OSA) is characterized by repetitive upper airway obstruction resulting in cyclic intermittent hypoxia (IH) during sleep in affected individuals. OSA occurs more frequently ...
Kinetics of [8-14C]adenine incorporation into growing HeLa cells

Abstract The time course of incorporation of [8- 14 C]adenine into purine bases of different RNA fractions in growing HeLa S3 cells has been studied. A high-molecular-weight RNA fraction, which resembles closely the microsomal RNA in HeLa cells, appears to be the end product in the biosynthesis of RNA. The data strongly suggest the nuclear origin of microsomal RNA in growing HeLa cells, with an RNA fraction (nuclear RNA) present in the nucleus as a polynucleotide precursor. A simple kinetic model is proposed, which under certain restrictive conditions may be used to define the “intracellular transport rate” of RNA from nucleus to cytoplasm.
Competing through relationships: Grounding relationship marketing in resource‐advantage theory

A common element of all views of relationship marketing is the “co‐operate‐to‐compete” thesis. That is, to be an effective competitor often requires one to be an effective co‐operator. One implication of this thesis is that not all instances of firms co‐operating with each other constitute anti‐competitive collusion. This article argues that, although neoclassical, perfect competition theory cannot provide a theoretical foundation for relationship marketing's “co‐operate‐to‐compete” thesis, the recently developed “resource‐advantage” theory of competition can do so. Furthermore, this article uses resource‐advantage theory to address the relationship portfolio conundrum. Specifically, the paper argues that firms should develop a relationship portfolio that is comprised of relationships that constitute relational resources.
In Concert and Alone: Divorce and Congregational Experience

Sociologists have paid little attention to the experience of divorce in religious congregations. Numerous quantitative studies suggest that religion can provide health and wellness during such life disruptions, but we know little about the social and individual processes that might foster these benefits. I address this gap in the literature drawing from data collected in a four-year ethnographic study of divorce and ending life partnerships across six religious traditions. I analyze the experiences of 41 individuals who ended life partnerships while active in their congregations. Despite intense points of communal connection through ritual, respondents named largely private strategies for settling heightened emotion, physical and psychological pain, and creating a new self. Permeating their communal experiences was a marked sense of aloneness, resulting from individual shame and congregational silence, as well as their understanding of divorce-work as ultimately private self-work.
Hyperinsulinemia in hyperthecosis of the ovaries

Fasting insulin concentrations and the insulin response to an oral glucose tolerance test were measured in six virilized women with ovarian hyperthecosis and six weight-matched normal women. For comparison, six women with polycystic ovarian disease were also studied. The diagnosis of hyperthecosis was confirmed in all six virilized women by histologic examination of the ovaries. The fasting insulin concentrations were increased in all of the hyperthecosis patients (84 +/- 32 microU/ml). Insulin response to an oral glucose tolerance test was greatly increased (p less than 0.01) in comparison to normal women and women with polycystic ovarian disease. Significant positive correlations were found between peripheral insulin concentrations and ovarian vein testosterone (r = 0.879, p less than 0.02), dihydrotestosterone (r = 0.866, p less than 0.03), and androstenedione (r = 0.992, p less than 0.01) levels. Insulin resistance persisted after removal of the ovaries even though androgen levels returned to normal. These results suggest that a significant degree of insulin resistance exists in women with hyperthecosis and that insulin stimulates ovarian stromal androgen synthesis and thus may play a role in the pathogenesis of ovarian hyperthecosis.
Real-time measurement of sodium chloride in individual aerosol particles by mass spectrometry

The method of particle analysis by mass spectrometry has been applied to the quantitative measurement of sodium chloride in individual particles on a real-time basis. Particles of known masses are individually introduced, in the form of a beam, into a miniature Knudsen cell oven (1600 K). The oven is fabricated from rhenium metal sheet (0.018 mm thick) and is situated in the ion source of a quadrupole mass spectrometer. A particle once inside the oven is trapped and completely volatilized; this overcomes the problem of partial volatilization due to particles bouncing from the filament surface. Individual particles are thermally volatilized and ionized inside the rhenium oven, and produce discrete sodium ion pulses whose intensities are measured with the quadrupole mass spectrometer. An ion pulse width of several milliseconds (4-12 ms) is found for particles in the mass range 1.3 x 10 to the -13th to 5.4 x 10 to the -11th g. The sodium ion intensity is found to be proportional to the particle mass to the 0.86-power. The intensity distribution for monodisperse aerosol particles possesses a geometric standard deviation of 1.09, showing that the method can be used for the determination of the mass distribution function with good resolution in a polydisperse aerosol.