bluuebunny/crossref_metadata_2025 huggingface dataset:
Emergency Department Reliance Among Rural Children in Medicaid in New York State
Authors: Uva Jane L. , Wagner Victoria L. , Gesten Foster C.
Published: April 2011

Abstract  Purpose: This study examines variation in emergency department reliance (EDR) between rural and metro pediatric Medicaid patients in New York State for noninjury, nonpoisoning primary diagnoses and seeks to determine the relationship between receipt of preventive care and the likelihood of EDR.

Methods: Rural/urban designations were based on Urban Influence Codes established by the United States Department of Agriculture (USDA). Healthcare Effectiveness Data and Information Set (HEDIS®) well‐visit measures were calculated using 2008 Medicaid claims and encounter data. Well‐child numerator status and location of residence variables were then entered as independent variables in multivariate logistic regression models. Models controlled for the effects of Medicaid financing system (fee‐for‐service vs managed care), Medicaid aid type, race/ethnicity, gender, and 2008 clinical risk group category.

Findings: The likelihood of EDR was higher in all age categories for rural compared to metro residing Medicaid children in New York State. Meeting HEDIS well‐child criteria was protective against emergency department (ED) reliance in the adolescence age group (OR = 0.84).

Conclusion: ED reliance is associated with rural residence. Increased access to primary and specialty care in rural settings could help reduce EDR, particularly among rural adolescents.
Milk Processed by Pulsed Electric Fields: Evaluation of Microbial Quality, Physicochemical Characteristics, and Selected Nutrients at Different Storage Conditions
Authors: Bermúdez‐Aguirre Daniela , Fernández Sulmer , Esquivel Heracleo , Dunne Patrick C. , Barbosa‐Cánovas Gustavo V.
Published: April 2011

Abstract:  Pulsed electric fields (PEF) technology was used to pasteurize raw milk under selected treatments. Processing conditions were: temperature 20, 30, and 40 °C, electric field 30.76 to 53.84 kV/cm, and pulse numbers 12, 24, and 30 for skim milk (SM), and 12, 21, and 30 for whole milk (WM) (2 μs pulse width, monopolar). Physicochemical parameters (pH, electrical conductivity, density, color, solids nonfat [SNF]) and composition (protein and fat content) were measured after processing. Shelf life of SM and WM was assessed after processing at 46.15 kV/cm, combined with temperature (20 to 60 °C) and 30 pulses. Mesophilic and psychrophilic loads and pH were evaluated during storage at 4 and 21 °C. Results showed minor variations in physicochemical properties after processing. There was an interesting trend in SM in SNF, which decreased as treatment became stronger; similar behavior was observed for fat and protein, showing a 0.18% and 0.17% decrease, respectively, under the strongest conditions. Protein and fat content decreased in WM samples treated at 40 °C, showing a decrease in protein (0.11%), and an even higher decrease in fat content. During storage, PEF‐treated milk samples showed higher stability at 4 °C with minor variations in pH; after 33 d, pH was higher than 6. However samples at 21 °C showed faster spoilage and pH dropped to 4 after 5 d. Growth of mesophilic bacteria was delayed in both milks after PEF processing, showing a 6‐ and 7‐log cycles for SM and WM, respectively, after day 25 (4 °C); however, psychrophilic bacteria grew faster in both cases.

Practical Application:  Pulsed electric fields (PEF) technology in the pasteurization of liquid food products has shown positive results. Processing times can be reduced considerably, which in turn reduces the loss of nutrients and offers important savings in energy. PEF has been used successfully to pasteurize some liquid foods, but it is still not used commercially in milk pasteurization, although several trials have shown the positive effects of PEF milk pasteurization, which could allow for its future use at the industrial level.
In Vitro Batch Fecal Fermentation Comparison of Gas and Short‐Chain Fatty Acid Production Using “Slowly Fermentable” Dietary Fibers
Authors: Kaur Amandeep , Rose Devin J. , Rumpagaporn Pinthip , Patterson John A. , Hamaker Bruce R.
Published: April 2011

Abstract:  Sustained colonic fermentation supplies beneficial fermentative by‐products to the distal colon, which is particularly prone to intestinal ailments. Blunted/delayed initial fermentation may also lead to less bloating. Previously, we reported that starch‐entrapped alginate‐based microspheres act as a slowly fermenting dietary fiber. This material was used in the present study to provide a benchmark to compare to other “slowly fermentable” fibers. Dietary fibers with previous reports of slow fermentation, namely, long‐chain inulin, psyllium, alkali‐soluble corn bran arabinoxylan, and long‐chain β‐glucan, as well as starch‐entrapped microspheres were subjected to in vitro upper gastrointestinal digestion and human fecal fermentation and measured over 48 h for pH, gas, and short‐chain fatty acids (SCFA). The resistant fraction of cooked and cooled potato starch was used as another form of fermentable starch and fructooligosaccharides (FOS) served as a fast fermenting control. Corn bran arabinoxylan and long‐chain β‐glucan initially appeared slower fermenting with comparatively low gas and SCFA production, but later fermented rapidly with little remaining in the final half of the fermentation period. Long‐chain inulin and psyllium had slow and moderate, but incomplete, fermentation. The resistant fraction of cooked and cooled potato starch fermented rapidly and appeared similar to FOS. In conclusion, compared to the benchmark slowly fermentable starch‐entrapped microspheres, a number of the purported slowly fermentable fibers fermented fairly rapidly overall and, of this group, only the starch‐entrapped microspheres appreciably fermented in the second half of the fermentation period.

Practical Application:  Consumption of dietary fibers, particularly commercial prebiotics, leads to uncomfortable feelings of bloating and flatulence due to their rapid degradation in our large intestine. This article employs claimed potential slowly fermenting fibers and compares their fermentation rates with a benchmark slow fermenting fiber that we fabricated in an in vitro simulation of the human digestive system. Results show a variety of fermentation profiles only some of which have slow and extended rate of fermentation.
Effects of Cyclodextrin Type on Vitamin C, Antioxidant Activity, and Sensory Attributes of a Mandarin Juice Enriched with Pomegranate and Goji Berries
Authors: Navarro Patricia , Nicolas Tamara San , Gabaldon José A. , Mercader‐Ros María T. , Calín‐Sánchez Ángel , Carbonell‐Barrachina Ángel A. , Pérez‐López Antonio José
Published: April 2011

Abstract:  The effects of the addition of cyclodextrins (CDs), β‐CD, or HP‐β‐CD (1%), on the protection of antioxidant compounds of mandarin juices enriched with pomegranate extract and goji berries juice, was studied. Juices were prepared and after their thermal treatment (98 °C, 30 s) they were stored at 4 °C during 75 d. Vitamin C content, CIE L*a*b* color, antioxidant capacity, retinol equivalents, and sensory properties were studied. Losses on vitamin C were higher (6%) for juices with β‐CD than juices with HP‐β‐CD. Retinol equivalents degradation was lower (3.4%) in juices with HP‐β‐cyclodextrins than in those treated with β‐CD. Lower losses were observed for the instrumental and sensory color intensity in juices with HP‐β‐CD addition. Finally, the antioxidant capacity was also higher in juices treated with HP‐β‐CD. Finally, the overall sensory quality of juices with HP‐β‐CD was the best one after 30 d of cold storage. Even though β‐CD addition did not cause any improvement compared with control juice (without CD addition), the benefits of adding HP‐β‐CD to this particular juice were shown in almost all parameters under study.

Practical Application:  The present study deals with the practical aspects of the utilization of CDs and CD‐complexes in the food industry. The molecular encapsulation of lipophilic food ingredients with CD are supposed to improve the stability of flavors, vitamins, colorants, and antioxidant activity, leading to extended product shelf life. The HP‐β‐CD treated mandarin juice enriched with pomegranate extract and juice of goji berries will have a more intense color, higher vitamin C content, retinol equivalents, and antioxidant activity during storage and shelf life than control juices, with no CD addition.
Internal Quality and Shelf Life of Eggs Coated with Oils from Different Sources
Authors: Ryu Kyeong Nam , No Hong Kyoon , Prinyawiwatkul Witoon
Published: April 2011

Abstract:  Selected internal quality and shelf life of eggs coated with oils from differences sources (mineral oil, canola oil, corn oil, grape seed oil, olive oil, soybean oil, and sunflower oil) were evaluated during 5 wk of storage at 25 °C. As the storage time increased, weight loss increased whereas Haugh unit and yolk index values decreased. Throughout the 5 wk of storage, eggs coated with oils, regardless of oil sources, possessed better albumen and yolk quality than the control noncoated eggs. Oil coating minimized weight loss of eggs (<0.8%) compared with that (7.26%) of the noncoated eggs after 5 wk of storage at 25 °C. No significant differences in internal quality (weight loss, Haugh unit, yolk index, and albumen pH) were generally observed among oil‐coated eggs during 5 wk of storage. Based on the Haugh unit, the grade of noncoated eggs changed from AA at 0 wk to A at 1 wk and to B after 3 wk whereas that of oil‐coated eggs from AA at 0 wk to A at 4 wk and maintained A grade until 5 wk. This study demonstrated that oil coating, irrespective of oil sources, preserved the internal quality, minimized weight loss (<0.8%), and extended the shelf life of eggs by at least 3 wk longer than observed for the noncoated eggs at 25 °C storage. Soybean oil was a more practical option as a coating material for eggs due to its low cost.

Practical Application:  Eggs are highly perishable and susceptible to internal quality deterioration when stored above 7 °C. Refrigeration of eggs may be seldom practiced in some developing regions of the world. Therefore, an alternative method, that is inexpensive yet effective, to preserve the internal quality of eggs and to prevent microbial contamination is needed. Oil coating has been proven to preserve the internal quality, prolong shelf life, and minimize weight loss of eggs. This study demonstrated that, compared with other vegetable oils, soybean oil was a more practical option as a coating material for eggs during 5 wk of storage at 25 °C due to its low cost.
Associations between number of different type of care meetings with social network and improvement in mental well‐being in adolescents at risk of first‐episode psychosis
Authors: Granö Niklas , Karjalainen Marjaana , Anto Jukka , Itkonen Arja , Edlund Virve , Roine Mikko
Published: April 2011

Aim: As research in the care of people at risk of developing first‐episode psychosis has mostly focused on cognitive behavioural therapy and antipsychotic medication, little is known about associations between changes in mental well‐being and effect of people participating in the care.

Methods: Multiprofessional early intervention team met with adolescents who are at risk of psychosis, including coworkers and their families. Correlations were calculated between change scores in prepsychotic, functioning ability, quality of life (QoL), depression and anxiety scales, and number of family, coworker and adolescent‐participating social network meetings, and total number of social network meetings during the care.

Results: Larger change scores in functioning ability were positively associated with the number of social network meetings with participating coworker (P = 0.041), but not with other types of participant meetings. Larger change scores in prepsychotic symptoms were positively associated with the number of meetings where the adolescent was participating (P = 0.001), the number of network meetings where the coworker was participating (P = 0.007) and the number of all meetings (P = 0.001). The number of any other type of meetings did not associate with change scores in QoL, depression and anxiety.

Conclusion: According to the present results, adolescents at risk of psychosis seem to benefit from the inclusion of coworkers from the adolescents' natural surroundings in care; this could help to increase functioning ability. Different combinations of meetings, such as larger number of total meetings, larger number of meetings with the adolescent and larger number of meetings with coworkers from the adolescents' natural surroundings, seem to associate with stronger decrease in pre‐psychotic symptoms.
Usefulness of alkaline hydrogen peroxide oxidation to analyze eumelanin and pheomelanin in various tissue samples: application to chemical analysis of human hair melanins
Authors: Ito Shosuke , Nakanishi Yukiko , Valenzuela Robert K. , Brilliant Murray H. , Kolbe Ludger , Wakamatsu Kazumasa
Published: April 2011

Eumelanin and pheomelanin in tissue samples can be specifically measured as the markers pyrrole‐2,3,5‐tricarboxylic acid (PTCA) and 4‐amino‐3‐hydroxyphenylalanine after acidic permanganate oxidation and hydroiodic acid hydrolysis, respectively. Those degradation methods, although widely applied, are not easily performed in most laboratories. To overcome this difficulty, we developed alkaline H2O2 oxidation in 1 M K2CO3 that produces, in addition to the eumelanin marker PTCA, thiazole‐2,4,5‐tricarboxylic acid (TTCA) and thiazole‐4,5‐dicarboxylic acid (TDCA) as markers for pheomelanin and pyrrole‐2,3‐dicarboxylic acid (PDCA) as a marker for 5,6‐dihydroxyindole‐derived eumelanin. Those four degradation products can be easily separated by HPLC and analyzed with ultraviolet detection. The alkaline H2O2 oxidation method is simple, reproducible and applicable to all pigmented tissues. Its application to characterize eumelanin and pheomelanin in human hair shows that PTCA and TTCA serve as specific markers for eumelanin and pheomelanin, respectively, although some caution is needed regarding the artificial production of TTCA from eumelanic tissue proteins.
Resolving conflicting social categories: The role of age‐related executive ability
Authors: Hutter Russell R. C. , Wood Chantelle , Dodd Georgina F.
Published: April 2011

We investigated the effect of age‐related decline in executive ability on the application of emergent features to incongruent social category conjunctions (e.g., male midwife). When forming an impression of an incongruent conjunction, older adults used more emergent attributes (attributes associated exclusively with the category conjunction and not the constituents), relative to younger adults. Moreover, this relationship was mediated by a reduction in inhibitory ability (measured using a Stroop task) and processing speed (measured using a Digit Symbol Substitution Test, DSST). These findings are consistent with the notion that executive ability is pivotal in understanding social functioning in older adults. We discuss the implications of these findings for the continuing development of models outlining the processes and stages involved in perceiving social category conjunctions.
The mysterious microcircuitry of the cerebellar nuclei
Authors: Uusisaari Marylka , De Schutter Erik
Published: April 2011

Abstract  The microcircuitry of cerebellar cortex and, in particular, the physiology of its main element, the Purkinje neuron, has been extensively investigated and described. However, activity in Purkinje neurons, either as single cells or populations, does not directly mediate the cerebellar effects on the motor effector systems. Rather, the result of the entire cerebellar cortical computation is passed to the relatively small cerebellar nuclei that act as the final, integrative processing unit in the cerebellar circuitry. The nuclei ultimately control the temporal and spatial features of the cerebellar output. Given this key role, it is striking that the internal organization and the connectivity with afferent and efferent pathways in the cerebellar nuclei are rather poorly known. In the present review, we discuss some of the many critical shortcomings in the understanding of cerebellar nuclei microcircuitry: the extent of convergence and divergence of the cerebellar cortical pathway to the various cerebellar nuclei neurons and subareas, the possible (lack of) conservation of the finely‐divided topographical organization in the cerebellar cortex at the level of the nuclei, as well as the absence of knowledge of the synaptic circuitry within the cerebellar nuclei. All these issues are important for predicting the pattern‐extraction and encoding capabilities of the cerebellar nuclei and, until resolved, theories and models of cerebellar motor control and learning may err considerably.
The cerebrovascular response to carbon dioxide in humans
Authors: Battisti‐Charbonney A. , Fisher J. , Duffin J.
Published: April 2011

Non‐technical summary  Two mechanisms control brain blood flow by changing blood vessel diameter: autoregulation maintains flow in the face of perfusion pressure changes, and brain metabolism adjusts flow to meet metabolic requirements. Brain blood vessel reactivity to CO2 and O2 is an important component of the latter. We used a specialised rebreathing technique to change CO2 over a wide range at constant O2, estimating brain blood flow responses from measurements of middle cerebral artery flow velocity. We found that below a threshold CO2, blood pressure was unchanged, but blood flow increased in response to CO2. This response had a sigmoidal shape, centred at a CO2 close to resting. Above the threshold, both blood flow and pressure increased with CO2. We concluded that this method measures the brain blood flow reactivity to CO2 without the confounding influence of blood pressure changes. The results obtained contribute to our understanding of brain blood flow regulation.
Carbon monoxide: an emerging regulator of ion channels
Authors: Wilkinson William J. , Kemp Paul J.
Published: April 2011

Abstract  Carbon monoxide is rapidly emerging as an important cellular messenger, regulating a wide range of physiological processes. Crucial to its role in both physiology and disease is its ability differentially to regulate several classes of ion channels, including examples from calcium‐activated K+ (BKCa), voltage‐activated K+ (Kv) and Ca2+ channel (L‐type) families, ligand‐gated P2X receptors (P2X2 and P2X4), tandem P domain K+ channels (TREK1) and the epithelial Na+ channel (ENaC). The mechanisms by which CO regulates these ion channels are still unclear and remain somewhat controversial. However, available structure–function studies suggest that a limited range of amino acid residues confer CO sensitivity, either directly or indirectly, to particular ion channels and that cellular redox state appears to be important to the final integrated response. Whatever the molecular mechanism by which CO regulates ion channels, endogenous production of this gasotransmitter has physiologically important roles and is currently being explored as a potential therapeutic.
Mechanisms underlying a life‐threatening skeletal muscle Na+ channel disorder
Authors: Simkin Dina , Léna Isabelle , Landrieu Pierre , Lion‐François Laurence , Sternberg Damien , Fontaine Bertrand , Bendahhou Saïd
Published: April 2011

Non‐technical summary  Non‐dystrophic myotonias are rare disorders of skeletal muscle that are characterized by delayed relaxation of the muscle force or increased muscle contraction. These disorders result from genetic defects in sodium and chloride channels that are expressed in the muscle fibres. We describe here the functional consequences of a defect that has been identified in a severe form of myotonia that was lethal in newborn babies. We show that the affected skeletal muscle sodium channel protein, called Nav1.4, has an exacerbated activity that may well lead to muscle hyperexcitability in the reported patients. We strongly recommend treating patients with severe neonatal episodic laryngospasm with sodium channel blockers as soon as the diagnosis has been established.
The NCGC Pharmaceutical Collection: A Comprehensive Resource of Clinically Approved Drugs Enabling Repurposing and Chemical Genomics
Authors: Huang Ruili , Southall Noel , Wang Yuhong , Yasgar Adam , Shinn Paul , Jadhav Ajit , Nguyen Dac-Trung , Austin Christopher P.
Published: April 2011

Resources from the National Institutes of Health Chemical Genomics Center include a database and a physical collection of approved drugs.
Establishment of Antitumor Memory in Humans Using in Vitro–Educated CD8
+
T Cells
Authors: Butler Marcus O. , Friedlander Philip , Milstein Matthew I. , Mooney Mary M. , Metzler Genita , Murray Andrew P. , Tanaka Makito , Berezovskaya Alla , Imataki Osamu , Drury Linda , Brennan Lisa , Flavin Marisa , Neuberg Donna , Stevenson Kristen , Lawrence Donald , Hodi F. Stephen , Velazquez Elsa F. , Jaklitsch Michael T. , Russell Sara E. , Mihm Martin , Nadler Lee M. , Hirano Naoto
Published: April 2011

Antitumor CD8
+
T cells educated in vitro can persist as memory T cells and induce antitumor responses in humans without prior conditioning or cytokine treatment.
Blood Sample Supplants Biopsy?
Authors: Damani Samir
Published: April 2011

Donor-heart DNA circulating in transplant recipients pinpoints people at risk for rejection.
The Biological Response to Biologics
Authors: Lin Richard J.
Published: April 2011

The development of antidrug antibodies in rheumatoid arthritis patients reduces long-term drug efficacy.
Balloons with Brains
Authors: Skelly Christopher L.
Published: April 2011

Semiconductor devices and sensors integrated into biocompatible materials transform balloon catheters into a next-generation surgical tool.
Impact of Weight on Immune Cell Counts among HIV-Infected Persons
Authors: Crum-Cianflone Nancy F. , Roediger Mollie , Eberly Lynn E. , Ganesan Anuradha , Weintrob Amy , Johnson Erica , Agan Brian K. ,   Infectious Disease Clinical Research Program HIV Working Group
Published: April 2011

Prior studies have shown that weight may impact immune cell counts. However, few data exist about the relationship of weight and immune cell counts among HIV-infected patients. We examined documented HIV seroconverters (mean window, 15.7 months) in a prospective U.S. Military HIV Natural History Study (1 January 1986 to 20 January 2010). We estimated the association of the time-updated body mass index (BMI) category with changes in immune cell counts from HIV diagnosis across time (mean follow-up of 5.1 years) using multiply adjusted longitudinal linear mixed-effects models. Of 1,097 HIV seroconverters, 448 (41%) were overweight and 93 (8%) were obese at HIV diagnosis. Immune cell counts at HIV diagnosis did not significantly differ by BMI category. In the longitudinal models for those diagnosed before the advent of the highly active antiretroviral therapy (HAART) era, mean postdiagnosis decreases in the white cell count, total lymphocyte count, CD4 count, CD4 percentage, and CD4/CD8 ratio were less as the BMI category increased (all withPvalues of <0.05). Among HIV seroconverters diagnosed in the HAART era, obese compared to normal-weight patients had significantly smaller increases in CD4 counts, CD4 percentages, and the CD4/CD8 ratio (all withPvalues of <0.05). Similar findings were also noted among underweight versus normal-weight patients. In conclusion, although BMI was not associated with immune cell levels at the time of HIV diagnosis, weight appears to affect immune cells counts over the course of infection. In the HAART era, being either underweight or obese was associated with smaller increases in several important immune cell levels, including the CD4/CD8 ratio.
Taking the Gonococcus-Human Relationship to a Whole New Level: Implications for the Coevolution of Microbes and Humans
Authors: Shafer William M. , Ohneck Elizabeth A.
Published: April 2011

While horizontal gene transfer occurs frequently among bacterial species, evidence for the transfer of DNA from host to microbe is exceptionally rare. However, the recent report by Anderson and Seifert [mBio 2(1):e00005-11, 2011] provides evidence for such an event with the finding that 11% of
Neisseria gonorrhoeae
strains harbor a 685-bp sequence that is 98 to 100% identical to the human long interspersed nuclear element L1. While the function of this element in gonococci remains unclear, this finding significantly impacts our consideration of the coevolution of hosts and microbes, particularly that of humans and pathogens.
Absorption spectra of nucleic acid bases studied by the symmetry-adapted-cluster configuration-interaction (SAC-CI) method
Authors: Miyahara Tomoo , Nakatsuji Hiroshi
Published: April 2011

The ground and excited states of five nucleic acid bases (adenine, guanine, cytosine, uracil and thymine) were calculated by employing the SAC/SAC-CI (symmetry adapted cluster/SAC configuration-interaction) method. The absorption spectra with the SAC-CI method were compared with the experimental spectra. The spectra obtained with the SAC-CI method were in good agreement with the experimental spectra in gas phase. Comparisons with the calculations with other methods were made.
Acupuncture Does Not Influence Brainstem Auditory Evoked Potentials: A Volunteer Crossover Study
Authors: Usichenko Taras I , Lietz Peggy , Pavlovic Dragan , Schmidt Reinhardt , Wendt Michael , Mustea Alexander
Published: April 2011

Background

Although acupuncture is effective for treating several conditions, its site specificity is questionable.

Objective

To investigate whether acupuncture influences the brainstem auditory evoked potentials (BAEP).

Methods

10 healthy volunteers were enrolled according to inclusion criteria. One of four acupuncture points—TE3, GB43 (both auditory system-specific, according to traditional Chinese medicine) and non-specific acupuncture points HT7 and ST44—was needled during each session. Each volunteer received four sessions of acupuncture, with a 1-week interval between the sessions.

Results

Peak latencies and amplitudes of the BAEP were registered before and during each session of acupuncture. Pain intensity and the incidence of paraesthesia ( Qi sensation) during acupuncture were also registered. The peak latencies and amplitudes of the BAEP registered during acupuncture had not changed from the baseline levels. Needling of acupoint HT7 was most painful and induced the maximal incidence of Qi sensation.

Conclusions

Findings suggest that monitoring the BAEP is not a suitable technique for studying the immediate effects of acupuncture.
Flagship Species – Flagship Problems: recovery of species at risk and the conservation of biodiversity in Canada1This introduction is part of the virtual symposium “Flagship Species – Flagship Problems” that deals with ecology, biodiversity and management issues, and climate impacts on species at risk and of Canadian importance, including the polar bear (Ursus maritimus), Atlantic cod (Gadus morhua), Piping Plover (Charadrius melodus), and caribou (Rangifer tarandus).
Authors: Boates J. Sherman , Fenton M. Brock
Published: April 2011

This is an Introduction to a series of review articles, entitled Flagship Species – Flagship Problems, that identify, review, and address key problems, solutions, and contradictions linked to conservation and recovery of four iconic species at risk in Canada (polar bear, Ursus maritimus Phipps, 1774; Atlantic cod, Gadus morhua L., 1758; Piping Plover. Charadrius melodus Ord, 1824; caribou, Rangifer tarandus (L., 1758)), as well as one review article dealing with the more systemic impacts of habitat loss and degradation. The reviews are cast in the context of the broader challenge of maintaining and restoring biodiversity.
Conservation and management of Canada’s polar bears (Ursus maritimus) in a changing Arctic1This review is part of the virtual symposium “Flagship Species – Flagship Problems” that deals with ecology, biodiversity and management issues, and climate impacts on species at risk and of Canadian importance, including the polar bear (Ursus maritimus), Atlantic cod (Gadus morhua), Piping Plover (Charadrius melodus), and caribou (Rangifer tarandus).
Authors: Peacock E. , Derocher A.E. , Thiemann G.W. , Stirling I.
Published: April 2011

Canada has an important responsibility for the research, conservation, and management of polar bears ( Ursus maritimus Phipps, 1774) because the majority of polar bears in the world occur within the nation’s borders. Two fundamental and recent changes for polar bears and their conservation have arisen: (1) the ongoing and projected further decline of sea-ice habitat as a result of climate change and (2) the implementation of aboriginal land claims and treaties in Canada’s North. Science has documented empirical links between productivity of polar bear population and sea-ice change. Predictive modeling based on these data has forecast significant declines in polar bear abundance and distribution of polar bears. With the signing of northern land claims and treaties, polar bear management in Canada has integrated local aboriginal participation, values, and knowledge. The interaction of scientific and local perspectives on polar bears as they relate to harvest, climate change, and declining habitat has recently caused controversy. Some conservation, management, and research decisions have been contentious because of gaps in scientific knowledge and the polarization and politicization of the roles of the various stakeholders. With these ecological and governance transitions, there is a need to re-focus and re-direct polar bear conservation in Canada.
Correlates of recovery for Canadian Atlantic cod (Gadus morhua)1This review is part of the virtual symposium “Flagship Species – Flagship Problems” that deals with ecology, biodiversity and management issues, and climate impacts on species at risk and of Canadian importance, including the polar bear (Ursus maritimus), Atlantic cod (Gadus morhua), Piping Plover (Charadrius melodus), and caribou (Rangifer tarandus).
Authors: Hutchings Jeffrey A. , Rangeley Robert W.
Published: April 2011

The collapse of Atlantic cod ( Gadus morhua L., 1758) in the early 1990s, perhaps the greatest numerical loss of a Canadian vertebrate (1.5–2.5 billion reproductive individuals), is one from which the species has yet to recover. Populations, or stocks, are at or well below their conservation reference points. The lack of recovery has been linked to ongoing fishing mortality (targeted, bycatch), changes to life history (reductions in age and size at maturity, truncations in age and size structure), and increased natural mortality. Emergent and demographic Allee effects, coupled with altered interspecific interactions, render questionable the presumption that the recovery of heavily depleted populations can be reliably forecasted by population dynamical behaviour during decline. Contrary to international commitments and inconsistent with fishery rebuilding plans elsewhere, cod recovery plans exclude target and limit reference points, recovery timelines, and harvest control rules. We suggest that the long-term biodiversity, social, and economic benefits associated with cod recovery can be realised by novel changes, including quantitatively responsible recovery plans based on science-determined reference points, new or revised legislation, integrated management strategies, strengthened sustainable seafood certification practices, expansion of marine spatial planning and protected areas, and novel financial incentives for investment in long-term, sustainable fisheries.
Conservation of Piping Plover (Charadrius melodus) in North America: science, successes, and challenges1This review is part of the virtual symposium “Flagship Species – Flagship Problems” that deals with ecology, biodiversity and management issues, and climate impacts on species at risk and of Canadian importance, including the polar bear (Ursus maritimus), Atlantic cod (Gadus morhua), Piping Plover (Charadrius melodus), and caribou (Rangifer tarandus).
Authors: Gratto-Trevor C.L. , Abbott S.
Published: April 2011

There are only about 8000 Piping Plovers ( Charadrius melodus Ord, 1834) in existence. Because they depend on environments that are under intense human pressures and controls in both their breeding and wintering grounds, these birds and their habitats are highly managed in many areas across their range. Efforts to recover this endangered and threatened species have engaged thousands of people from Newfoundland to the Caribbean, and have provoked a ground-swell of public support and, at times, fury, as well as a considerable body of research. Although populations have increased substantially in the U.S. Atlantic and U.S. Great Lakes, this is not true of all regions. Significant issues still exist with respect to the efficacy of predator management; need for more accurate model input information; effects of climate, pollutants, and water management; habitat loss and degradation from recreation and development; and whether the cost and effort of management for this species can be maintained or increased where needed.
Conservation of caribou (Rangifer tarandus) in Canada: an uncertain future1This review is part of the virtual symposium “Flagship Species – Flagship Problems” that deals with ecology, biodiversity and management issues, and climate impacts on species at risk and of Canadian importance, including the polar bear (Ursus maritimus), Atlantic cod (Gadus morhua), Piping Plover (Charadrius melodus), and caribou (Rangifer tarandus).
Authors: Festa-Bianchet M. , Ray J.C. , Boutin S. , Côté S.D. , Gunn A.
Published: April 2011

Caribou ( Rangifer tarandus (L., 1758)) play a central role in the ecology and culture of much of Canada, where they were once the most abundant cervid. Most populations are currently declining, and some face extirpation. In southern Canada, caribou range has retreated considerably over the past century. The ultimate reason for their decline is habitat alterations by industrial activities. The proximate causes are predation and, to a lesser extent, overharvest. The most southerly populations of “Mountain” caribou are at imminent risk of extirpation. Mountain caribou are threatened by similar industrial activities as Boreal caribou, and face increasing harassment from motorized winter recreational activities. Most populations of “Migratory Tundra” caribou are currently declining. Although these caribou fluctuate in abundance over decades, changing harvest technologies, climate change, increasing industrial development and human presence in the North raise doubts over whether recent declines will be followed by recoveries. The Peary caribou ( Rangifer tarandus pearyi J.A. Allen, 1902), a distinct subspecies endemic to Canada’s High Arctic, has suffered drastic declines caused by severe weather, hunting and predation. It faces an increasing threat from climate change. While some questions remain about the reasons for the decline of Migratory Tundra caribou, research has clearly identified several threats to the persistence of “Boreal”, Mountain, and Peary caribou. Scientific knowledge, however, has neither effectively influenced policies nor galvanized public opinion sufficiently to push governments into effective actions. The persistence of many caribou populations appears incompatible with the ongoing pace of industrial development.
ON REPRESENTATIONS OF CYCLOTOMIC HECKE ALGEBRAS
Authors: OGIEVETSKY O. V. , POULAIN D'ANDECY L.
Published: April 2011

An approach, based on Jucys–Murphy elements, to the representation theory of cyclotomic Hecke algebras is developed. The maximality (in the cyclotomic Hecke algebra) of the set of the Jucys–Murphy elements is established. A basis of the cyclotomic Hecke algebra is suggested; this basis is used to establish the flatness of the deformation without using the representation theory.
HADRONIC TRANSITIONS FROM ϒ(4S) AS A PROBE OF FOUR-QUARK ADMIXTURE
Authors: VOLOSHIN M. B.
Published: April 2011

It is argued that the observed enhancement of the hadronic transition ϒ(4S) → ϒ(1S)η relative to ϒ(4S) → ϒ(1S)ππ can be explained if the resonance ϒ(4S) contains an admixture of a four-quark component, possibly due to the coupling to the meson channel [Formula: see text]. A test of the discussed mechanism by searching for the transition ϒ(4S) → ϒ(1S)η′(958) is suggested. Some properties of possible four-quark states related to the suggested one by the heavy quark spin symmetry are also discussed.
ON PERFORMANCE OF HIGH ENERGY PARTICLE COLLIDERS AND OTHER COMPLEX SCIENTIFIC SYSTEMS
Authors: SHILTSEV VLADIMIR
Published: April 2011

Many complex scientific and technical systems demonstrate exponential performance progress with time ∝ e+t/C. The characteristic progress time C, a measure of empirical difficulty and complexity, is analyzed for high energy elementary particle colliders, astrophysical searches for galaxies and exoplanets, protein structure determination, and compared with computers and thermonuclear fusion reactors. An explanation of the characteristic exponential progress is offered.
RECURRENCE NETWORKS: EVOLUTION AND ROBUSTNESS
Authors: STROZZI F. , POLJANSEK K. , BONO F. , GUTIÉRREZ E. , ZALDÍVAR J. M.
Published: April 2011

We analyze networks generated by the recurrence plots of the time series of chaotic systems and study their properties, evolution and robustness against several types of attacks. Evolving recurrence networks obtained from chaotic systems display interesting features from the point of view of robustness (in particular, those related to their connectivity), which could help in the design of systems with high capability and robustness for information diffusion. The approach is extended to cases where the equations of the chaotic system are not given (but are defined by their time series) using state-space reconstruction methods and we note that the general characteristics of the attractors generated by such systems are maintained under this transformation. A comparison with well-known complex network models is performed to illustrate the differences and similarities.
DYNAMIC PATTERNS OF POSTURAL FLUCTUATIONS DURING QUIET STANDING: A RECURRENCE QUANTIFICATION APPROACH
Authors: GHOMASHCHI HAMED , ESTEKI ALI , NASRABADI ALI MOTIE , SPROTT JULIEN CLINTON , BAHRPEYMA FARID
Published: April 2011

When standing quietly, the human body is continuously moving about an upright posture in an erratic fashion. Conventional posturographic analyses that ignore structure of postural steadiness time series do not fully characterize properties of sway dynamics. Recurrence quantification analysis is a technique that can extract the dynamics of postural fluctuations through several variables. In this study, standing-still-sway dynamics of intact and deteriorated postural control systems were investigated by recurrence quantification of stabilograms. The results indicated that both normal and changed postural fluctuations time series, despite erratic and irregular appearance, contain a hidden structure. Although the two components of postural sway originated from an integrated control system, they exhibit distinct dynamical patterns. More determinism, greater local stability, higher degrees of nonstationarity and more laminar states were observed in fore-aft movements. Our findings reveal that decay of postural control mechanism affects dynamical properties of postural control system (especially along mediolateral direction because of the type of impairment). Determinism, nonstationarity and rigidity of balance program as well as laminar states characteristics were increased due to deterioration of postural control system. These findings imply that these measures not only can be used as the pathologic measures to discriminate between group differences, but also provide new openings to understand the nature of postural sway.
ON LOCALLY CONFORMALLY FLAT GRADIENT SHRINKING RICCI SOLITONS
Authors: CAO XIAODONG , WANG BIAO , ZHANG ZHOU
Published: April 2011

In this paper, we first apply an integral identity on Ricci solitons to prove that closed locally conformally flat gradient Ricci solitons are of constant sectional curvature. We then generalize this integral identity to complete noncompact gradient shrinking Ricci solitons, under the conditions that the Ricci curvature is bounded from below and the Riemannian curvature tensor has at most exponential growth. As a consequence, we classify complete locally conformally flat gradient shrinking Ricci solitons with Ricci curvature bounded from below.
SINGULAR CYCLES AND Ck-ROBUST TRANSITIVE SET ON MANIFOLD WITH BOUNDARY
Authors: CARRASCO-OLIVERA D. , MORALES C. A. , SAN MARTÍN B.
Published: April 2011

Let M be a 3-manifold with boundary ∂M. Let X be a C∞, vector field on M, tangent to ∂M, exhibiting a singular cycle associated to a hyperbolic equilibrium σ∈∂M with real eigenvalues λss < λs < 0 < λu satisfying λs - λss - 2λu > 0. We prove under generic conditions and k large enough the existence of a Ck robust transitive set of X, that is, any Ck vector field Ck close to X exhibits a transitive set containing the cycle. In particular, C∞ vector fields exhibiting Ck robust transitive sets, for k large enough, which are not singular-hyperbolic do exist on any compact 3-manifold with boundary.
COUNTEREXAMPLES TO STRICHARTZ ESTIMATES FOR THE MAGNETIC SCHRÖDINGER EQUATION
Authors: FANELLI LUCA , GARCIA ANDONI
Published: April 2011

In space dimension n ≥ 3, we consider the magnetic Schrödinger Hamiltonian H = -(∇ - iA(x))2and the corresponding Schrödinger equation [Formula: see text] We show some explicit examples of potentials A, with less than Coulomb decay, for which any solution of this equation cannot satisfy Strichartz estimates, in the whole range of Schrödinger admissibility.
MULTIPLE FIBERS OF HOLOMORPHIC LAGRANGIAN FIBRATIONS
Authors: HWANG JUN-MUK , OGUISO KEIJI
Published: April 2011

We determine all possible multiplicities of general singular fibers of a holomorphic Lagrangian fibration, under the assumption that all components of the fibers are of Fujiki class. The multiplicities are at most 6 and the possible values are intricately related to the Kodaira type of the characteristic cycle.
SELF-ASSEMBLED SCAFFOLDS USING REACTION–DIFFUSION SYSTEMS: A HYPOTHESIS FOR BONE REGENERATION
Authors: GARZÓN-ALVARADO DIEGO A. , VELASCO MARCO A. , NARVÁEZ-TOVAR CARLOS A.
Published: April 2011

One area of tissue engineering concerns research into alternatives for new bone formation and replacing its function. Scaffolds have been developed to meet this requirement, allowing cell migration, bone tissue growth, transport of growth factors and nutrients, and the improvement of the mechanical properties of bone. Scaffolds are made from different biomaterials and manufactured using several techniques that, in some cases, do not allow full control over the size and orientation of the pores characterizing the scaffold. A novel hypothesis that a reaction–diffusion (RD) system can be used for designing the geometrical specifications of the bone matrix is thus presented here. The hypothesis was evaluated by making simulations in two- and three-dimensional RD systems in conjunction with the biomaterial scaffold. The results showed the methodology's effectiveness in controlling features such as the percentage of porosity, size, orientation, and interconnectivity of pores in an injectable bone matrix produced by the proposed hypothesis.
MECHANICAL PROPERTIES OF CHORDAE TENDINEAE OF THE MITRAL HEART VALVE: YOUNG'S MODULUS, STRUCTURAL STIFFNESS, AND EFFECTS OF AGING
Authors: MILLARD LAURA , ESPINO DANIEL M. , SHEPHERD DUNCAN E. T. , HUKINS DAVID W. L. , BUCHAN KEITH G.
Published: April 2011

Young's modulus and structural stiffness were determined for chordae tendineae of the mitral valve from young (18–26 weeks) and old (over 2 years) porcine hearts. For chordae from the posterior leaflet of the valve, the Young's modulus values were significantly higher (p < 0.05) for the thinner marginal chordae (59 ± 31 MPa young; 88 ± 21 MPa old) than for the thicker basal chordae (31 ± 4 MPa young; 28 ± 9 MPa old). Marginal chordae (both anterior and posterior) had significantly higher (p < 0.05) value for their Young's modulus in old (88 ± 21 MPa anterior and posterior) than in young (62 ± 17 MPa anterior, 59 ± 18 MPa posterior) pig hearts. There was no significant difference in structural stiffness between marginal and basal (anterior and posterior leaflets) or between strut chordae (that are associated with anterior the leaflet only) and marginal and basal chordae. However, the value of structural stiffness of chordae was significantly higher (p < 0.05) for old (2.2 ± 0.2 kN/m) than for young (2.0 ± 0.4 kN/m) chordae. These results show that aging affects the properties of chordae and that all chordae need to be included in finite element models of valve function.
AN ANALYTICAL APPROACH TO TRANSMISSION DYNAMICS OF INFECTIOUS DISEASES WITH WANING IMMUNITY
Authors: YILDIRIM AHMET , KOÇAK HÜSEYIN
Published: April 2011

In this study, we present a mathematical model that describes the dynamics of reinfection under the assumption that the vaccine-induced immune protection may wane over time. The qualitative analysis reveals that the disease eradication depends on vaccination coverage as well as on vaccine efficacy. Using an appropriate Lyapunov function, we established that the disease-free equilibrium is globally asymptotically stable if the vaccination coverage level exceeds a certain threshold value. We combined homotopy perturbation method (HPM) and Padé approximation technique for this problem. Numerical simulations support our analytical conclusions and illustrate possible behavior scenarios of the model.
A ROBUST AND EFFICIENT ALGORITHM FOR ST–T COMPLEX DETECTION IN ELECTROCARDIOGRAMS
Authors: SONG JINZHONG , YAN HONG , XIAO ZHIJUN , YANG XIANGLIN , ZHANG XIAODONG
Published: April 2011

Changes of ST–T complex are the main indicators in myocardial ischemia detection based on electrocardiogram (ECG) signals. However, ST–T complex is highly sensitive to interferences (baseline wandering, postural changes, electrode interference, etc.), especially T-wave has a large morphological variability. Therefore, the feature points of ECG ST–T complex are very difficult to detect accurately. Currently, the commonly used detection methods for ST-segment include R + x and J + x, but they often misjudges the T-wave rising limb as ST-segment. Therefore, a new accurate hybrid approach for ST–T detection was proposed in this paper. First, T-wave onsets and offsets were detected using regional method and T-wave peaks were located using function comparing method. Then, a squeeze approach for ST-segment detection was proposed based on R-wave peak and T-wave onset. Long-term ST database (LTST) verification demonstrated that the accuracy of ST–T detection reached above 91%. In addition, it had a good timeliness and robustness and was easy to implement.