cssi/SciSciGPT-SciSciNet huggingface dataset:
Micro-zooplankters in the plankton communities of the upper waters of the eastern tropical Pacific

Abstract The numerical abundance, biomass, and taxonomic composition of the micro-zooplankton and chlorophyll, phaeophytin, and total seston levels were determined for six depth intervals within the upper 200 m at 12 locations from approximately 10°N to 12°S latitude on longitude 105°W. Data on the hydrography, phytoplankton inorganic nutrients, larger zooplankton standing stocks, and phytoplankton productivity at the various sites was available through the EASTROPAC program. Average micro-zooplankton volume over the euphotic zone showed a threefold range, from 15 mm 3 /m 3 at the southerly extreme of our sampling to 47 mm 3 /m 3 near the Equator. The relative taxonomic composition of the micro-zooplankton populations within the three size classes of material separated was similar to that described from earlier studies of California Current populations. Highly significant positive correlations were found between micro-zooplankton abundance and chlorophyll levels in the various depth intervals when ‘groups’ of stations, delineated on the basis of similar hydrographic features, or all stations in the study were considered. Standing stock biomass of micro-zooplankton averaged 34% (range, 23–66%) of that of the phytoplankton, both estimated in terms of dry weight over the euphotic zone at the different sites. This was considerably greater than was earlier indicated for stations in the California Current. Calculations, based on assumptions regarding micro-zooplankton feeding rates, suggested that these small animal plankters might be consuming an average of 70% (range, 39–104%)_of the daily phytoplankton organic carbon production at stations along the transect. The same calculation using data from weekly observations taken between April and September at a site five miles off the La Jolla coast indicated an average of only 23% (range, 7–52%) for this relationship. Micro-zooplankton biomass within the euphotic zone at the various locations relative to the larger zooplankton was suggested to be about an average 24%, but this calculation was complicated by the different depths of sampling for the two populations and the methods of determining their volumes.
Trends in the electric quadrupole fields at dilute impurity sites in transition-metal--transition-metal alloys

The available electric-field-gradient data at transition-metal impurity sites and at host sites in transition-metal hosts has been inspected for indications of trends in alloying behavior. The raw data separate the gradients into two groups, depending on whether the host metal has over, or under, half-filled $d$ bands. The gradients for any given probe atom are largely independent of which host, in a given group, is involved, running counter to simple chemical intuition. Analysis is complicated by various intra- and inter-atomic contributions to the field gradient and the practice has been adopted of presuming that one or another contribution prevails and normalizing the experimental data by an effective field appropriate to the probe atom and to the contribution involved. The normalized results suggest that the observed gradients, by their very magnitude, must be largely intraatomic in origin. Granted this, and assuming that it is the $d$ electrons which are primarily responsible, we find that, while there is scatter in the data, the gradients at host and impurity sites, in the under-half-filled $d$-shell hosts, show little chemical variation with either differing impurity or differing host. The normalized results for the over-half-filled $d$-shell hosts, on the other hand, appear to show a chemical trend which is also to be seen in the enthalpies of formation of the more concentrated alloys. The normalizations, if we assume intra-atomic effects, required estimates of the field gradient due to a single valence electron. The renormalized-atom scheme was employed to obtain the contributions from $d$- and valence $p$-electron charge. It is not widely appreciated as to how important $p$ electron bonding can be to the gradients. Sternheimer antishielding factors, ${\ensuremath{\gamma}}_{\ensuremath{\infty}}$, were also required. Lacking values for some of the elements of concern, a simple scaling with the size of the atom was introduced. This was inferred from a number of sequences of ions and then applied to predictions for the $5d$ elements.The scaling worked well and should do so in other cases as well.
Multi-scale solid oxide fuel cell materials modeling

Performance and degradation of fuel cell components are discussed in a multi-scale framework in this paper. Electrochemical reactions in a solid oxide fuel cell occur simultaneously as charge and gas pass through the anode, electrolyte, and cathode to produce electric power. Since fuel cells typically operate at high temperatures for long periods of time, performance degradation due to aging of the fuel cell materials should be examined. This phenomenon is treated in a multi-scale framework by considering how microstructure evolution affects the performance at the macro-scale. Mass and charge conservation equations and electrochemical kinetic equations are solved to predict the overall cell performance using the local properties calculated at the micro-scale. Separately, the microstructures assigned to the macroscopic integration points are evolved via the Cahn–Hilliard equation using an experimentally calibrated kinetic parameter. The effective properties of the evolving microstructure are obtained by homogenization and incorporated in the macro-scale calculation. The proposed model is applied to a solid oxide fuel cell system with a nickel/yttria stabilized zirconia (Ni/YSZ) cermet anode. Our model predicts performance degradation after extended hours of operation related to nickel particle coarsening and the resulting decrease in triple phase boundary (TPB) density of the anode material. The investigation of the microstructural effects on TPB density suggests that using Ni and YSZ particles of similar size may retard performance degradation due to anode aging.
A Numerical Model of In-Channel Pebble Bed Thermal Storage for a Solar Chimney

In this study, solar chimney performance is numerically modeled. Previously published models have considered water bags and natural earth as means to store daytime thermal energy for nighttime operation of the system. The present model considers in-channel pebble bed thermal storage. A one-dimensional, implicit time stepping numerical model is developed to predict solar chimney performance throughout a 24 hour period. The model is partially verified with available experimental data. The daily energy, daily efficiency and heat transfer characteristics of the solar chimney with pebble bed thermal storage are summarized. The numerical simulation showed that by introducing a pebble bed, nightly exit velocities reach 40% of the peak daytime velocity. However, the daily kinetic energy delivered by a solar chimney with pebble bed thermal storage is much less than a traditional solar chimney, suggesting pebble bed thermal storage is more practicable in building heating applications as opposed to power generation.Copyright © 2012 by ASME
The Cards I Was Dealt My Life With Familial Hypercholesterolemia

I don’t remember a time in my life without the word cholesterol. The images, explanations, and feelings over this word have changed through the years, but it’s always been there. I have familial hypercholesterolemia (FH). My low-density lipoprotein (or “bad” cholesterol) levels have never been “desirable,” and I have xanthomas—yellowish cholesterol deposits under my skin–around my eyes, behind my knees, and under my arms. My grandfather had a fatal heart attack at 30 and my mother had open-heart surgery at 42. These are the facts, but just writing those simple statements brings tears to my eyes and puts fear in my gut. This story isn’t about the facts, though. This story goes beyond low-density lipoprotein, PCSK9 inhibitors, and statins. This is my story as a person dealing with the cards I was dealt. My first blood test was when I was ≈9 years old. It wasn’t good. While the exact breakdown escapes my memory, I am certain the total cholesterol level was ≈420. My mother cried, which made me cry. I had no idea why this was sad, but when you’re a kid and your mommy is crying, you cry with her. I don’t remember the doctor being sympathetic, because they usually weren’t. Growing up in Florida, my parents never had health insurance. Luckily, the state offered a health plan for children of low-income homes called Healthy Kids. While it meant I could go to the doctor, the parameters of the program meant I could simply visit the hospital and whatever doctor was in their pediatric residency at the time. With each new doctor and new set of laboratories, we met disapproving shakes of the head and lectures on my diet. My parents tried to take care of it with the knowledge they had. My mother lost her father as …
Differential Appearance of T Cell Subsets in the Large and Small Intestine of Neonatal Mice

We examined the appearance of intestinal intraepithelial lymphocytes (IEL) during the first 12 wk of life to gain insight into postnatal factors that contribute to the differences found between IEL in the large and small intestines of adult mice. Intestinal T cells were very infrequent at birth, but increased in number in the large and small intestine during the first 4 wk of life and then stabilized. The small intestinal epithelium at 2 wk of age contained mostly T cell receptor (TCR) αβ+, CD2+ T cells, unlike IEL in adult mice, which were composed of nearly equal proportions of CD2−, TCR αβ+ and TCR γδ+ cells. Between 2 and 3 wk of age, TCR γδ+, CD2− IEL increased greatly in the small intestine, whereas TCR αβ+ cells expressing CD2 decreased. By contrast, IEL in the large intestine at 2 and 3 wk of age were mostly TCR αβ+, CD2+ T cells similar to large intestinal IEL in adult mice. And finally, the expression of CD69 increased earlier and to higher levels on TCR αβ+ and TCR γδ+ IEL in the small intestine than in the large intestine. Our results demonstrate that IEL in the large and small intestine are phenotypically similar during suckling and that differences between these populations are established after weaning. Furthermore, the earlier accumulation of IEL with an activated adult IEL phenotype in the small intestine suggests that these T cells mature or expand in the gut and contribute to the maturation of immune function during postnatal life in mice.
UNPRECEDENTED OBSERVATION OF LACTONE HYDROLYSIS BY THE AAL2 MECHANISM

Abstract Five-membered lactones are shown to undergo exchange of the ring oxygen when heated at reflux in 6 N HCl / H 2 18 O. It is concluded that lactones can be hydrolyzed by the previously unreported A Al 2 mechanism.
Continuum of outer-and inner-sphere mechanisms for organic electron transfer. steric modulation of the precursor complex in paramagnetic (ion-radical) self-exchanges

Transient 1:1 precursor complexes for intermolecular self-exchange between various organic electron donors (D) and their paramagnetic cation radicals (D+*), as well as between different electron acceptors (A) paired with their anion radicals (A-*), are spectrally (UV-NIR) observed and structurally (X-ray) identified as the cofacial (pi-stacked) associates [D, D+*] and [A-*, A], respectively. Mulliken-Hush (two-state) analysis of their diagnostic intervalence bands affords the electronic coupling elements (HDA), which together with the Marcus reorganization energies (lambda) from the NIR spectral data are confirmed by molecular-orbital computations. The HDA values are found to be a sensitive function of the bulky substituents surrounding the redox centers. As a result, the steric modulation of the donor/acceptor separation (rDA) leads to distinctive electron-transfer rates between sterically hindered donors/acceptors and their more open (unsubstituted) parents. The latter is discussed in the context of a continuous series of outer- and inner-sphere mechanisms for organic electron-transfer processes in a manner originally formulated by Taube and co-workers for inorganic (coordination) donor/acceptor dyads-with conciliatory attention paid to traditional organic versus inorganic concepts.
Phenotypic heterogeneity and genotypic instability in coupled cellular arrays

Abstract The dynamic origins of phenotypic heterogeneity and genotypic instability and hypermutation have been investigated in simulated tissues comprised of 900-25 600 cells each represented by initially identical Rossler attractors running in the chaotic domain. This attractor, representing the cell cycle behavior of individual cells in the array, has previously been used to model the dynamic behavior of mammalian cells in culture. In these tissue constructs, the behavior of an individual cell is modified by its interactions with its immediate neighbors as a consequence of diffusive coupling through one of the variables. Differentiation within the initially identical population of attractors is manifested as a position dependent set of novel stable trajectories in phase space that are revealed through the use of return maps. These self-mapping patterns, which we define as the phenotype of the cell, are periodic and stable over a considerable period of time. A comparison of tissues whose individual cell cycle attractor phases describe an archimedean spiral with those that exhibit S-T chaos, or turbulence, suggests that the heterogeneous phenotype of tumor tissues is better modeled by turbulence. Instability in the spiral array exists primarily at the boundary between periodic regions of differing phase and trajectory, and involves infrequent excursions by these boundary cells away from their stables trajectories. Such instabilities are hypothesized to play an important role in the amplification, hypermutation, and gene conversion events seen in certain normal biological tissues and tumors.
Stability of two tethered unsymmetrical earth- pointing bodies.

This investigation deals with the motion, in a circular orbit, of a flexible satellite consisting of two identical, but unsymmetrical, rigid bodies connected together by a single tether. The differential equations governing the motions of this assembly, regarded as having nine degrees of freedom (the motion of the composite mass center presumed known and the mass of the tether neglected), are presented. An "earth-pointing" motion, which corresponds to a particular solution to the set of differential equations, is accomplished when the assembly moves such that the rigid end bodies are at rest in the orbital reference frame and such that the connecting tether remains coincident with the line joining the center of the earth and the mass center of the satellite. A procedure for predicting the instabilities of such a motion is developed and employs the method of Routhian arrays. Some general conclusions concerning the influence of the tether on vehicle stability are reported. In particular, it is established that the elastic and damping properties of the tether are immaterial, while the tether length and tethering geometry at the end bodies are of principal importance.
In situ uptake of mercury by the intertidal mussel, Mytilus californianus

Abstract The in situ uptake of mercury in tissues of Mytilus californianus was studied by exposing control specimens to waters at four depths near a submarine wastewater discharge for a period of 24 weeks. The response patterns observed for digestive gland, adductor muscle and gonadal tissues were strikingly different. Digestive gland concentrations increased rapidly to the heightened levels found for indigenous specimens. On the other hand, changes in the mercury content of adductor muscle were not statistically significant, and gonadal tissues generally exhibited a low rate of increase. No correlation with depth was observed.
Resident perceptions of work hour limitations: has the 80-hour work week doomed the 3-year Internal Medicine residency?

To the Editor:—The study by Lin et al.1 in the July issue of the Journal of General Internal Medicine may signify the beginning of the end of the 3-year Internal Medicine residency. The study suggests that work hour limitations have significantly compromised the accumulative clinical experience Internal Medicine residents receive during their 3 years of residency. What is not known is whether this loss in clinical exposure has now made it impossible to consistently graduate quality Internists in 3 years. Applying the Dreyfus continuum of learning, the expectation is that graduating residents should function at the proficient level.2 One issue has been in defining “proficient”, in particular when evaluating cognitive skills such as critical thinking. The ACGME Outcome Project has residency programs now focusing on what their residents are learning instead of what they are teaching. The ACGME general competencies more fully define the skills residents must master to become expert clinicians, but do not indicate where on the learning continuum they should be at the end of 3 years. Even without a clear definition of what the proficient Internist is, there are several reasons to be concerned that 3 years are no longer adequate to train Internal Medicine residents. The complexity of Internal Medicine seems to increase daily. The ACGME competencies illustrate all the skills residents must now master. The study of Lin et al. quantifies the fragmented resident–patient relationship that most of us see on a daily basis. Faculty must devote more time to revenue generation at the expense of time previously dedicated to teaching residents.3 Therefore, residents are expected to learn more with less quality patient time and less faculty mentorship in the same 3 years their predecessors had. Before we can determine whether residencies need to be lengthened, we need to better understand where on the learning continuum graduating residents are under the current system. This will require discipline-specific outcome measures. Then we must decide where residents should be on the learning curve when they graduate. Only then can we determine the optimal duration of residency training. If recent changes in GME have shifted the Dreyfus continuum to the right, it would indicate that we are graduating a higher percentage of competent, instead of proficient, physicians. Competent behavior is generally considered that which meets a minimal standard. This has never been the goal of Graduate Medical Education.
Socioeconomic factors and racial disparities in kidney disease outcomes

African Americans suffer disproportionately from advanced and progressive chronic kidney disease (CKD). Socioeconomic factors are believed to play an important role in this disparity, and likely influence African Americans' increased risk of CKD through multiple pathways. Low socioeconomic status (SES) may contribute to racial disparities in CKD because of the greater prevalence of poverty, for example, among African Americans as compared with whites. However, low SES has a stronger relation with CKD among African Americans than among whites, underscoring that the context and magnitude of socioeconomic influences on CKD outcomes varies between these populations. These socioeconomic influences may produce new or potentiate existing racial differences in biology. This review discusses what is known about the role of SES in explaining racial disparities in CKD, highlights several knowledge gaps in this area, and suggests future directions toward the elimination of disparities in CKD.
Extending the Zolotarev–Frobenius approach to quadratic reciprocity

In 1872, Zolotarev observed that the Legendre symbol $$\left( \frac{a}{p}\right) $$ is the sign of the permutation of $$\mathbb Z/p\mathbb Z$$ induced by multiplication by $$a$$ and used this to prove the quadratic reciprocity law. We pursue Zolotarev’s formalism in a more general setup, which can be expressed in terms of a Dedekind domain $$R$$ with finite residue fields or in terms of finite principal commutative rings. In this level of generality we define and compute Zolotarev symbols—by comparison to Jacobi symbols, when the residue rings have odd order—and arrive at Zolotarev reciprocity, a sort of “potential quadratic reciprocity law”. To realize this potential one must compute the sign of a certain permutation. When $$R = \mathbb Z$$ , this was done by Zolotarev. When $$R = \mathbb F_q[t]$$ for an odd prime power $$q$$ , we compute the sign of this permutation and obtain a new proof of the quadratic reciprocity law of Dedekind and Artin.
Neurocognitive Consequences of HIV Infection in Older Adults: An Evaluation of the “Cortical” Hypothesis

The incidence and prevalence of older adults living with HIV infection is increasing. Recent reports of increased neuropathologic and metabolic alterations in older HIV+ samples, including increased cortical beta-amyloid, have led some researchers to suggest that aging with HIV may produce a neuropsychological profile akin to that which is observed in “cortical” dementias (e.g., impairment in memory consolidation). To evaluate this possibility, we examined four groups classified by HIV serostatus and age (i.e., younger ≤40 years and older ≥50 years): (1) Younger HIV− (n = 24); (2) Younger HIV+ (n = 24); (3) Older HIV− (n = 20); and (4) Older HIV+ (n = 48). Main effects of aging were observed on episodic learning and memory, executive functions, and visuoconstruction, and main effects of HIV were observed on measures of verbal learning and memory. The interaction of age and HIV was observed on a measure of verbal recognition memory, which post hoc analyses showed to be exclusively attributed to the superior performance of the younger HIV seronegative group. Thus, in this sample of older HIV-infected individuals, the combined effects of HIV and aging do not appear to result in a “cortical” pattern of cognitive deficits.
Fluvastatin inhibits FLT3 glycosylation in human and murine cells and prolongs survival of mice with FLT3/ITD leukemia

FLT3 is frequently mutated in acute myeloid leukemia (AML), but resistance has limited the benefit of tyrosine kinase inhibitors (TKI). We demonstrate that statins can impair FLT3 glycosylation, thus leading to loss of surface expression and induction of cell death, as well as mitigation of TKI resistance. Immunofluorescence microscopy confirms a reduction in surface localization and an increase in intracellular FLT3/internal tandem duplication (ITD) accumulation. This aberrant localization was associated with increased STAT5 activation but inhibition of both MAPK and AKT phosphorylation. Growth inhibition studies indicate that FLT3/ITD-expressing cells were killed with an IC50 within a range of 0.2-2μM fluvastatin. Several mechanisms of resistance could be circumvented by fluvastatin treatment. An increase in the IC50 for inhibition of phosphorylated FLT3/ITD by lestaurtinib caused by exogenous FLT3 ligand, resistance to sorafenib caused by the D835Y or FLT3/ITD N676K mutations, and activation of the IL-3 compensatory pathway were all negated by fluvastatin treatment. Finally, fluvastatin treatment in vivo reduced engraftment of BaF3 FLT3/ITD cells in Balb/c mice. These results demonstrate that statins, a class of drugs already approved by the US Food and Drug Administration, might be repurposed for the management of FLT3 mutant acute myeloid leukemia cases either alone or in conjunction with FLT3 TKI.
SU‐FF‐T‐06: Megavoltage CT Imaging Enables CT‐Based Low‐Doserate Brachytherapy Planning Without CT‐Compatible Applicators

Purpose: To determine feasibility of megavoltage computed tomography (MVCT) imaging for low dose rate (LDR) brachytherapy for cervical carcinoma.Method and Materials: A helical tomotherapy treatment unit (Tomotherapy HiArt ,Tomotherapy Inc., Madison, WI) using a nominal 3.5 MV x‐ray beam was used to image a dosimetry phantom containing standard, non‐CT compatible Fletcher‐Suit applicators and dummy Cs‐137 tube sources (3M Model 6500). The phantom contained several small steel BB markers which were used as dose points. The MVCT images were transferred to a commercially available treatment planning system (CMS XiO 4.2, Computerized Medical Systems, St. Louis, MO). Digitally reconstructed radiographs (DRRs) were generated from the MVCT data set, and doses(dose rates) were calculated at the phantom dose points using standard 2D, film‐based dosimetry methods. Doses were also calculated using a CT‐based, 3D dosimetry technique in which the brachytherapy source tips and ends were localized directly on MVCT images. Separate experiments were performed to verify the spatial accuracy of the MVCT image reconstruction in‐phantom. Results: In‐phantom localization accuracy was 0.6 ± 0.3 mm, slightly less than the size of an axial MVCT image pixel and less than half of the MVCT slice thickness. Point doses in‐phantom calculated by 2D and by 3D methods agreed within an average of 1.5%. The techniques developed for successful MVCT imaging in‐phantom can be used to calculate 3D dose distributions in a human patient undergoing a traditional (non‐CT compatible) Fletcher‐Suit implant. Conclusion: MVCT imaging allows CT‐based dosimetry planning without the use of special, “CT‐compatible” applicators.
Flow structure in a wide microchannel with surface grooves

Abstract We present an experimental analysis of pressure-driven flow in a high (62:1) aspect ratio microchannel having a repeated herringbone surface pattern. The velocity field is determined at the groove–channel interface and at the midplane of the channel using microscopic particle image velocimetry. At Reynolds numbers of 0.08, 0.8 and 8, we observe secondary flow patterns consisting of counter-rotating flow cells aligned in the streamwise direction. The strength of this secondary flow is inhibited by fluid inertia when Re = 8 . The resulting flow structure can be viewed as splitting one wide channel into multiple smaller channels without the use of solid boundaries.
Evoked responses in brain motor areas during the immobility reflex ("animal hypnosis").

Abstract The immobility reflex (IR) is a behavior in which spinal reflexes and movements are profoundly inhibited. Subcortical motor systems control this behavior, and two important motor areas, the medullary reticular formation (MRF) and caudate nucleus, were studied for changes in excitability during the IR. Single and paired stimulation of several sites (caudate, septum, hippocampus, and MRF) were used to evoke responses which were averaged by computer. In all stimulus conditions, MRF and caudate responses contained distinct and relatively short-latency components, suggesting relatively direct interconnections, although neuroanatomical evidence for some of these paths is scanty. Under paired stimulus conditions, the early components of 2nd responses were conspicuously attenuated in MRF responses to septal and hippocampal stimulation and caudate responses to septal and MRF stimulation. Delayed, or secondary, components of responses were notably indistinct and inconspicuous in all MRF responses, whereas they were conspicuously distinct and sustained during paired stimulation in caudate responses to septal and hippocampal stimulation. Unexpectedly, in no case did the IR clearly affect amplitude or waveform of the initial components of the responses. However, the delayed components were always altered by the IR. This and other evidence suggests that the IR is a behavior that is characterized by profound inhibition of movement without corresponding decrease in primary excitability and discriminative capacity, although secondary neural processing reactions are affected in a wide variety of neural systems.
Membrane trafficking and transport: overview and neurologic implications.

ALS= : amyotrophic lateral sclerosis; BMP= : bone morphogenic protein; CMT= : Charcot-Marie-Tooth; CMT2= : Charcot-Marie-Tooth type II; COP= : coat complex; dHMN= : distal hereditary motor neuronopathy; ER= : endoplasmic reticulum; ERGIC= : endoplasmic reticulum–Golgi complex intermediate compartment; ESCRT= : endosomal sorting complex required for transport; GTPase= : guanidine triphosphatase; HAP= : huntingtin-associated protein; HSAN= : hereditary sensory and autonomic neuropathy; HSP= : hereditary spastic paraplegia; MFN2= : mitofusin 2; MVB= : multivesicular body; PI= : phosphoinositide; REEP= : receptor-expression-enhancing protein; RTN= : reticulon; SNARE= : soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor; TGN= : trans-Golgi network; VAMP= : vesicle associated membrane protein; VAPB= : vesicle-associated membrane protein-associated protein B. Normal neural function depends on the appropriate delivery and removal of proteins and lipids at pre-, post- or extrasynaptic membranes. The membrane transport system comprises the endoplasmic reticulum (ER), the Golgi complex, secretory vesicles, endosomes, and lysosomes. This system is involved in 2 fundamental cellular pathways, the secretory and the endocytic pathway. The secretory pathway transports most of the transmembrane and secreted proteins from their site of synthesis in the ER to their final destinations, including the presynaptic membrane. Endocytosis participates in control of the composition of the plasma membrane, intra- and intercellular signaling, and uptake of essential nutrients. Vesicular trafficking along the secretory and endocytic pathways depends on interactions of several membrane proteins with the cytoskeleton. The directionality and specificity of membrane trafficking depends on a large number of transmembrane, cytoskeletal, and adaptor proteins that are involved in membrane shaping and remodeling, and in vesicular trafficking along microtubules. Mutations affecting many of these proteins manifest with different phenotypes, including hereditary spastic paraplegia (HSP), distal hereditary motor neuronopathy (dHMN), Charcot-Marie-Tooth type II (CMT2) neuropathy, and hereditary sensory and autonomic neuropathy (HSAN). The mechanisms of membrane trafficking, secretory pathways, and endocytosis, and their clinical correlations have been recently reviewed.1,–,13 Membrane trafficking involves several common mechanisms, including vesicular biogenesis, transport along microtubules, and tethering and fusion of the vesicle membrane with the recipient compartment (figure). Figure Mechanisms involved in the secretory and endocytic pathways in neurons The secretory pathway proteins from their site of synthesis in the endoplasmic reticulum (ER) to the Golgi complex and from there to their final destinations in the membrane or synaptic vesicles. ER structure depends of interactions of several interacting membrane proteins, including atlastatin-1, receptor-expression-enhancing protein1 (REEP), and spastin, which also …
Investigating Individual and Occupational Factors and their Interactions on Low Back Pain Severity in Workers

Low back pain (LBP) is the most prevalent work-related musculoskeletal disorder. Current ergonomic prevention strategies focus on reducing the effect of occupational risk factors. However, other underlying mechanisms may exist since not all workers performing the same task develop an injury. In this study, 36 LBP patients with a previous MRI scan were recruited to investigate the effects of individual and occupational factors and their interactions on LBP severity. Individual and occupational factors information was obtained through questionnaires. LBP severity ratings were obtained through a self-reported Visual Analog Scale (VAS) and the Oswestry Disability Index (ODI) questionnaire and served as the dependent variables. Stepwise linear regression analysis was performed on the variables. For ODI, a model consisting of interaction effects between individual and occupational risk factors with an adjusted R2 value of 0.84 was obtained. These preliminary results may help to develop models to predict and, he...
The public health implications of antiretroviral therapy – 2011 and beyond

2011 will mark the 30 th anniversary of the first description of AIDS, and the 15 th year since combination antiretroviral therapy (ART) was introduced. Since its introduction, ART has had profound impact on AIDS incidence and mortality in industrialized countries, and international collaboration, mainly through the Global Fund and the President’s Emergency Plan for AIDS Relief, has provided treatment to more than 4 million HIV-infected persons in low and middle income settings. Supplement: Abstracts of the Tenth International Congress on Drug Therapy in HIV Infection http://www.biomedcentral.com/content/pdf/1758-2652-13-S4-info.pdf Conference: Tenth International Congress on Drug Therapy in HIV Infection 7-11 November 2010 Glasgow, UK (Published: 8 November 2010) doi:10.1186/1758-2652-13-S4-K2 Cite this article as: De Cock: The public health implications of antiretroviral therapy – 2011 and beyond. Journal of the International AIDS Society 2010 13(Suppl 4):K2. Full text: PubMed Central:
Eating disorders, religious practices and pastoral counseling

The authors sent questionnaire surveys to 200 members of the clergy regarding their experiences with individuals with eating disorders. Eighty-four responded, and nearly half of those had seen at least one individual with an eating disorder in pastoral counseling during the last year. Fifty bulimic females were surveyed also. Most professed strong religious beliefs, and the majority indicated that they prayed or worshipped privately at least several times a month. The importance of understanding and respecting each patient's religious beliefs is emphasized.
A low cost portable parabolic solar concentrator for combined heat and power

This paper details the development of a portable parabolic solar concentrator system. The prototype is designed to be able to provide high quality heat or steam using a mobile, self contained system. A UV stable thermoplastic mirror is coupled with a lightweight parabolic frame and a vacuum insulated heat collection pipe. The system features a novel heliostat design, allowing simple collector scalability to virtually any size. A 1.5 square meter mirror was prototyped and tested to compare the design's performance with traditional stationary parabolic solar concentrators. The durability, cost, and set-up procedure for the system is also commented upon. In addition, this paper describes the possible applications of the system including desalination, power generation, and industrial heat supply.
Effects of locus coeruleus lesions upon cerebral monoamine content, sleep-wakefulness states and the response to amphetamine in the cat

Summary The purpose of the present study was to investigate the effects of complete lesions of the noradrenaline locus coeruleus neurons upon wakefulness and paradoxical sleep. Radiofrequency lesions of the nucleus were performed in 8 chronically implanted cats which were continuously recorded with an EEG for 5 days prior to and 21 days following the lesions, when they were sacrified. In 3 of these animals amphetamine (2 mg/kg) was administered on one control day and on the 10th day post-lesion. Following sacrifice, monoamine content was assayed in discrete brain regions, and the lesion was examined in Nissl-stained sections of the pons. (1) The majority (¯x69%) of the locus coeruleus was bilaterally destroyed by the lesions which only minimally exceeded the boundaries of the nucleus within the dorsolateral pontine tegmentum. Noradrenaline was depleted by a mean of 85% in the paleo- and neocortex and by a mean of 60% in the thalamus and midbrain. (2) EEG activation reappeared within 12–48 h following the lesion and represented a normal percentage of recording time on the 3rd and subsequent days post-lesion. The behavioral arousal and long-lasting EEG activation produced by amphetamine was qualitatively and quantitatively the same pre- and post-lesion. (3) Despite alteration of certain components, paradoxical sleep reappeared within 48 h and recovered to normal amounts by the second week post-lesion. Muscle atonia was permanently absent in 7 animals. Ponto-geniculo-occipital (PGO) spiking was acutely redistributed across all states and chronically reduced in frequency (by a mean of 50%) within paradoxical sleep. These results indicate that the noradrenaline locus coeruleus neurons are not necessary for the tonic maintenance of EEG activation that occurs in normal wakefulness and in amphetamine-produced arousal. Furthermore, these neurons are not necessary for the occurrence of paradoxical sleep, although they may be involved in modulation of PGO spiking.
Utilization of the bovine papillomavirus type 1 late-stage-specific nucleotide 3605 3' splice site is modulated by a novel exonic bipartite regulator but not by an intronic purine-rich element.

Bovine papillomavirus type 1 (BPV-1) late gene expression is regulated at both transcriptional and posttranscriptional levels. Maturation of the capsid protein (L1) pre-mRNA requires a switch in 3′ splice site utilization. This switch involves activation of the nucleotide (nt) 3605 3′ splice site, which is utilized only in fully differentiated keratinocytes during late stages of the virus life cycle. Our previous studies of the mechanisms that regulate BPV-1 alternative splicing identified three cis-acting elements between these two splice sites. Two purine-rich exonic splicing enhancers, SE1 and SE2, are essential for preferential utilization of the nt 3225 3′ splice site at early stages of the virus life cycle. Another cis-acting element, exonic splicing suppressor 1 (ESS1), represses use of the nt 3225 3′ splice site. In the present study, we investigated the late-stage-specific nt 3605 3′ splice site and showed that it has suboptimal features characterized by a nonconsensus branch point sequence and a weak polypyrimidine track with interspersed purines. In vitro and in vivo experiments showed that utilization of the nt 3605 3′ splice site was not affected by SE2, which is intronically located with respect to the nt 3605 3′ splice site. The intronic location and sequence composition of SE2 are similar to those of the adenovirus IIIa repressor element, which has been shown to inhibit use of a downstream 3′ splice site. Further studies demonstrated that the nt 3605 3′ splice site is controlled by a novel exonic bipartite element consisting of an AC-rich exonic splicing enhancer (SE4) and an exonic splicing suppressor (ESS2) with a UGGU motif. Functionally, this newly identified bipartite element resembles the bipartite element composed of SE1 and ESS1. SE4 also functions on a heterologous 3′ splice site. In contrast, ESS2 functions as an exonic splicing suppressor only in a 3′-splice-site-specific and enhancer-specific manner. Our data indicate that BPV-1 splicing regulation is very complex and is likely to be controlled by multiple splicing factors during keratinocyte differentiation.
Etiology of Dyspnea in Elite and Recreational Athletes

AbstractBackground: Breathing complaints are common in athletes. Studies have suggested that the prevalence of asthma and exercise-induced bronchoconstriction (EIB) is higher in elite athletes than the general population. Vocal cord dysfunction (VCD) may mimic asthma and EIB as a cause of dyspnea in athletes. However, the majority of studies to date have primarily relied on symptoms to diagnose VCD, and there are limited data on coexistence of asthma, EIB, and/or VCD. It is well established that symptoms alone are inadequate to accurately diagnose EIB and VCD. Our goal was to define via objective testing the prevalence of asthma, EIB, VCD alone, or in combination in a cohort of athletes with respiratory complaints. Methods: A retrospective chart review was done of 148 consecutive athletes (collegiate, middle school, high school, and recreational) referred to a tertiary care center's asthma center for evaluation of respiratory complaints with exercise. An evaluation including medical history, physical exam...
Aortic Arch Anomalies

Magnetic resonance imaging has become the gold standard for imaging the aortic arch with the ability to demonstrate not only the arterial branching pattern, but also the relationship of aorta and its branches to the trachea and bronchi. Examples of four major aortic arch types--left aortic arch, right aortic arch, double aortic arch and persistent fifth aortic--with most of their variations are demonstrated.
Design and implementation of a real-time image noise canceller

Image noise cancellation is necessary to remove noise generated in communication systems or remote video conferencing systems. Processing speed has become a challenge as a consequence of the increasing image resolution, especially in visual information processing. This paper presents the design and implementation of a real-time image noise canceller. Two-dimensional least mean square (TDLMS) algorithm is employed as the adaptive filter for noise cancellation. This algorithm is modified and designed with two concurrent phases: filter coefficient adjustment phase and image noise cancellation phase, with each phase mapping into a pipeline structure, therefore achieving real-time performance. The image noise canceller is implemented using hardware description language VHDL and is prototyped on Field Programmable Gate Array (FPGA) for system reconfiguration. A data buffer is developed using SelectRAM (BRAM) embedded in a Virtex FPGA to overcome the bandwidth limitation between external memory and the noise cancellation processor. The FPGA embedded multipliers are also employed to improve the processing speed. Tested using standard images, this real-time image noise canceller could process up to 1528 frames of 256 by 256 pixel images per second and could reach up to 10.4dB signal to noise ration improvement.
DISCRIMINATION OF CONSPECIFIC MALE MOLT ODOR SIGNALS BY MALE CRAYFISH, ORCONECTES RUSTICUS

For many organisms, chemoreception plays a key role in numerous aspects of daily life. Crayfish use chemical signals to find mates, warn conspecifics of predators, and relay social status. While many of these situations have been studied in detail, behavior of conspecifics toward chemical signals from molted individuals has not been thoroughly examined. The physiology of crayfish changes dramatically during molting (ecdysis), which in turn may change both the chemical content and concentrations of the chemical cues released into the water. We hypothesized that conspecifics are sensitive to chemicals released during molting. A Y-maze experimental design was used to test for differential responses to various molt-related chemical stimuli presented to intermolt male crayfish (Orconectes rusticus). The sources of chemical stimuli were recently molted male crayfish, intermolt male crayfish, control (aged tank water), and food (fish). Behavioral indices of response included initial arm choice, time spent in each arm, time spent at each nozzle, number of arm changes, and meral spread at each nozzle. Experiments were also conducted where crayfish were presented the same chemical stimuli in each arm to obtain measures of locomotor activity in the different stimuli. In addition, orientation parameters such as walking speed, walking speed to source, and distance to source were analyzed. Intermolt individuals spent more time in the presence of molt signals, although the food stimulus was more attractive than any other stimuli tested. Crayfish showed a significant initial arm choice when molt stimulus was paired with control. During the identical presentation of chemical stimuli, crayfish showed an increase in locomotor activity in the molt and food chemical stimuli than in the intermolt and control chemical stimuli. There were no significant differences in orientation parameters between chemical stimuli. These results show that crayfish can discriminate molted male conspecifics from the other chemical stimuli tested.
Secondary structures and intramolecular interactions in fragments of the B-loops of naturally occurring analogs of epidermal growth factor

Abstract Structures of naturally occurring analogs of the B-loop fragment of human epidermal growth factor-like (hEGF-like) polypeptides were examined by molecular dynamics simulation in order to predict their secondary structures, to find structural similarity and to detect any weakly polar aromatic-aromatic (7t-7t) or amide-aromatic (N-Jt) interactions which stabilize the structures. NPT molecular dynamics simulations (1 ns) were performed by the GRO- MACS package with SPC/E water using a weak temperature and pressure coupling method. During the sampling time, the structures of all peptides showed a characteristic secondary structure with a turn and bend at residues 4–7, and a β-sheet, β-bridge and random coil at the N- and C-terminal regions. Though the peptide chains were flexible, the stabilization effect of the N-it interactions was indicated in some cases by the angles and distances between the centroids of aromatic planes of the side-chains and the H-atom of peptide bonds and the planes of the aro...
Procedure for Site Assessment of the Potential for Tsunami Debris Impact

AbstractTsunami debris can place large demands on the structures it impacts. The types of potential debris and impact forces they generate are not well understood, and relatively little consideration is taken for the risk of tsunami debris strikes during structural design. A procedure is outlined to assess the site-specific potential for debris impact and its significance to structures. The procedure involves a categorization of potential debris based on fundamental characteristics. It includes an assessment of the ability and likelihood of debris transport, as constrained by the topography and the constructed environment. Data from aerial surveys and on-ground surveys after the March 2011 Tohoku tsunami are used to demonstrate and validate the considerations proposed for an assessment of debris and its transport. Instances of structural damage found during the site survey and that potentially resulted from debris strikes are reported. These cases are evaluated to correlate the proposed debris categories ...
A Rapid, Sensitive Method for the Quantitation of N-Acetyl-S-(2-Hydroxyethyl)-l-Cysteine in Human Urine Using Isotope-Dilution HPLC-MS-MS

Because of increasing concern about exposure to carcinogens and other toxicants, reliable methods for biological monitoring of potentially exposed populations must be developed. For biological monitoring to be useful, appropriate biomarkers of exposures to xenobiotics must be identified, and sensitive, specific methods for quantifying the targeted biomarker must be developed. We have developed a sensitive and selective method for the analysis of N-acetyl-S-(2-hydroxyethyl)-L-cysteine (HEMA), urinary metabolite of at least three different known human carcinogens (vinyl chloride, ethylene oxide, and ethylene dibromide). The method uses strong anion-exchange solid-phase extraction and isotope-dilution high-performance liquid chromatography-tandem mass spectrometry. Our method is simple and is not labor intensive; the preparation time per sample is less than 10 min. Because urine samples vary in both their concentration and ion strength, intersample variability in HEMA recovery during the extraction is large. To overcome this inherent limitation, we use the isotope-dilution technique, which allows a complete correction for the extraction recovery for each sample. The limit of detection of the method is 0.68 microgram/L in a 1-mL urine sample with a coefficient of variation of 22% (determined by replicate analyses at both 4 and 11 micrograms/L) and an accuracy indistinguishable from 100%. Preliminary analyses of urine from a population with no known overt exposure to the parent toxicants show a frequency of detection of approximately 75%, which indicates that this method has the sensitivity to detect urinary HEMA derived from environmental exposure. We are currently using this method to establish a reference range of background exposure to these toxicants in the U.S. population.