bluuebunny/crossref_metadata_2025 huggingface dataset:
Minireview: Global Regulation and Dynamics of Ribonucleic Acid
Authors: Keene Jack D.
Published: March 2010

Gene expression starts with transcription and is followed by multiple posttranscriptional processes that carry out the splicing, capping, polyadenylation, and export of each mRNA. Interest in posttranscriptional regulation has increased recently with explosive discoveries of large numbers of noncoding RNAs such as microRNAs, yet posttranscriptional processes depend largely on the functions of RNA-binding proteins as well. Glucocorticoid nuclear receptors are classical examples of environmentally reactive activators and repressors of transcription, but there has also been a significant increase in studies of the role of posttranscriptional regulation in endocrine responses, including insulin and insulin receptors, and parathyroid hormone as well as other hormonal responses, at the levels of RNA stability and translation. On the global level, the transcriptome is defined as the total RNA complement of the genome, and thereby, represents the accumulated levels of all expressed RNAs, because they are each being produced and eventually degraded in either the nucleus or the cytoplasm. In addition to RNA turnover, the many underlying posttranscriptional layers noted above that follow from the transcriptome function within a dynamic ribonucleoprotein (RNP) environment of global RNA-protein and RNA-RNA interactions. With the exception of the spliceosome and the ribosome, thousands of heterodispersed RNP complexes wherein RNAs are dynamically processed, trafficked, and exchanged are heterogeneous in size and composition, thus providing significant challenges to their investigation. Among the diverse RNPs that show dynamic features in the cytoplasm are processing bodies and stress granules as well as a large number of smaller heterogeneous RNPs distributed throughout the cell. Although the localization of functionally related RNAs within these RNPs are responsive to developmental and environmental signals, recent studies have begun to elucidate the global RNA components of RNPs that are dynamically coordinated in response to these signals. Among the factors that have been found to affect coordinated RNA regulation are developmental signals and treatments with small molecule drugs, hormones, and toxins, but this field is just beginning to understand the role of RNA dynamics in these responses.
Aldose Reductase Regulates Vascular Smooth Muscle Cell Proliferation by Modulating G1/S Phase Transition of Cell Cycle
Authors: Tammali Ravinder , Saxena Ashish , Srivastava Satish K. , Ramana Kota V.
Published: March 2010

Abnormal proliferation of vascular smooth muscle cells (VSMC) is a key feature of development of cardiovascular complications, atherosclerosis, and restenosis. Patients with diabetes have higher risk for restenosis after coronary angioplasty than nondiabetic patients due to hyperglycemia-induced release of cytokines such as TNF-α. However, the molecular mechanisms regulating VSMC proliferation remain unclear. Herein, we report that inhibition of the polyol pathway enzyme aldose reductase (AR) prevents high glucose (HG)- and/or TNF-α-induced VSMC proliferation by accumulating cells at the G1 phase of the cell cycle. Treatment of VSMC with AR inhibitor sorbinil prevented HG- as well as TNF-α-induced phosphorylation of retinoblastoma protein and activation of E2F-1. Inhibition of AR also prevented HG- and TNF-α-induced phosphorylation of cyclin-dependent kinase (cdk)-2 and expression of G1/S transition regulatory proteins such as cyclin D1, cyclin E, cdk-4, c-myc, and proliferative cell nuclear antigen. More importantly, inhibition of AR prevented the increased expression of E2F-1 and proliferative cell nuclear antigen in diabetic rat aorta. Treatment of VSMC with the most abundant and toxic lipid aldehyde 4-hydroxy-trans-2-nonenal (HNE) or its glutathione conjugate [glutathionyl (GS)-HNE] or AR-catalyzed product of GS-HNE, GS-1,4-dihydroxynonane, resulted in increased E2F-1 expression. Inhibition of AR prevented HNE- or GS-HNE-induced but not GS-1,4-dihydroxynonane-induced up-regulation of E2F-1. Collectively, these results show that AR could regulate HG- and TNF-α-induced VSMC proliferation by altering the activation of G1/S-phase proteins such as E2F-1, cdks, and cyclins. Thus, inhibition of AR may be a useful therapeutic approach in preventing vascular complications.
“Enough! or Too Much”
Authors: Downes Peg
Published: March 2010

College and university English departments always are active places, but those in many public liberal arts colleges are notably pleasant, as well. What accounts for this? Though these small academic units clearly learn much from large research institutions, perhaps the learning can be mutual. A question arises, however: can this oxymoronic blend of high-pitched professionalism and felicity be maintained?
Cell migration that orients the dorsoventral axis is coordinated with anteroposterior patterning mediated by Hedgehog signaling in the early spider embryo
Authors: Akiyama-Oda Yasuko , Oda Hiroki
Published: March 2010

The early embryo of the spider Achaearanea tepidariorum is emerging as a model for the simultaneous study of cell migration and pattern formation. A cell cluster internalized at the center of the radially symmetric germ disc expresses the evolutionarily conserved dorsal signal Decapentaplegic. This cell cluster migrates away from the germ disc center along the basal side of the epithelium to the germ disc rim. This cell migration is thought to be the symmetry-breaking event that establishes the orientation of the dorsoventral axis. In this study, knockdown of a patched homolog, At-ptc, that encodes a putative negative regulator of Hedgehog (Hh) signaling, prevented initiation of the symmetry-breaking cell migration. Knockdown of a smoothened homolog, At-smo, showed that Hh signaling inactivation also arrested the cells at the germ disc center, whereas moderate inactivation resulted in sporadic failure of cell migration termination at the germ disc rim. hh transcript expression patterns indicated that the rim and outside of the germ disc were the source of the Hh ligand. Analyses of patterning events suggested that in the germ disc, short-range Hh signal promotes anterior specification and long-range Hh signal represses caudal specification. Moreover, negative regulation of Hh signaling by At-ptc appears to be required for progressive derepression of caudal specification from the germ disc center. Cell migration defects caused by At-ptc and At-smo knockdown correlated with patterning defects in the germ disc epithelium. We propose that the cell migration crucial for dorsoventral axis orientation in Achaearanea is coordinated with anteroposterior patterning mediated by Hh signaling.
Laminar Fluid Flow around Two Wall-Mounted Cubes of Arbitrary Configuration
Authors: Eslami M , Tavakol M M , Goshtasbirad E
Published: March 2010

The problem of flow field around multiple bluff bodies mounted on a surface is of great significance in different fields of engineering. In this study, a computational fluid dynamics (CFD) code is developed to calculate three-dimensional (3D) steady state laminar fluid flow around two cuboids of arbitrary size and configuration mounted on a surface in free stream conditions. This study presents the results for two cubes of the same size mounted on a surface in both inline and staggered arrangements. Streamlines are plotted for various combinations of the distance between the two cubes and Reynolds number. Moreover, the effects of different parameters on vortical structures, separation, and reattachment points are discussed. Also, velocity and pressure distributions are plotted in the wake region behind the two cubes. It is clearly shown that how the presence of the second cube changes the flow field and the vortical structures in comparison with the case of a single cube.
Percutaneous inner-ear access via an image-guided industrial robot system
Authors: Baron S , Eilers H , Munske B , Toennies J L , Balachandran R , Labadie R F , Ortmaier T , Webster III R J
Published: March 2010

Image-guided robots have been widely used for bone shaping and percutaneous access to interventional sites. However, due to high-accuracy requirements and proximity to sensitive nerves and brain tissues, the adoption of robots in inner-ear surgery has been slower. In this paper the authors present their recent work towards developing two image-guided industrial robot systems for accessing challenging inner-ear targets. Features of the systems include optical tracking of the robot base and tool relative to the patient and Kalman filter-based data fusion of redundant sensory information (from encoders and optical tracking systems) for enhanced patient safety. The approach enables control of differential robot positions rather than absolute positions, permitting simplified calibration procedures and reducing the reliance of the system on robot calibration in order to ensure overall accuracy. Lastly, the authors present the results of two phantom validation experiments simulating the use of image-guided robots in inner-ear surgeries such as cochlear implantation and petrous apex access.
Influencing expert judgment: Attributions of crime causality
Authors: Murray Jennifer , Thomson Mary E. , Cooke David J. , Charles Kathy E.
Published: March 2010

Purpose. The present research aimed to investigate the effects of attribution on expert clinical judgment in comparison to semi‐experts and laypeople. Two research questions were addressed. First, would experts be less subject to attributional manipulations, in terms of their perceived ratings of dangerousness, than would semi‐experts or laypeople? Second, would experts be less subject to attributional manipulations, in terms of their assessments of offender responsibility, than would semi‐experts or laypeople?

Method. A 3×3×2 mixed groups design was implemented. Participants read nine crime scenarios that had been internally or externally manipulated. For each scenario, participants were asked to rate offender dangerousness, offender responsibility, and the seriousness of the crime and to suggest a suitable sentence length. Targeted recruitment was employed, yielding 12 experts, 21 semi‐experts, and 22 laypeople.

Results. Offenders were considered to be more responsible for their actions and more dangerous to others in the internal manipulations than in the external ones across all crime types and by all levels of expertise. Findings indicate that semi‐experts are less subject to the influence of attributional manipulations than both experts and laypeople. Marked similarities in the pattern of expert and lay person judgments can be observed from the present analyses.

Conclusions. The current findings lend support to previous research in the area in that similarities between expert and lay person judgment were observed. However, through expanding and clarifying the levels of expertise investigated, the current findings highlight the need for greater research into the distinct ‘semi‐expert’ group.
Role of N-acetyl-N-nitroso-tryptophan as nitric oxide donor in the modulation of HIF-1-dependent signaling
Authors: Berchner-Pfannschmidt Utta , Tug Suzan , Hu Jun , Reyes Buena Delos , Fandrey Joachim , Kirsch Michael
Published: March 2010

N-Acetyl-N-nitroso-tryptophan (NANT) is well known for its capacity to generate nitric oxide (NO)-releasing compounds. It is unknown, however, whether NANT can be successfully applied as a precursor of NO in a complex biological environment such as a cell culture system. NO donors can be useful to induce the transcription factor hypoxia-inducible factor 1 (HIF-1) that coordinates the protection of cells and tissues from the lack of oxygen, termed hypoxia. HIF-1 degradation is controlled by prolyl hydroxylase 2 (PHD2) which needs to be inhibited for HIF-1 accumulation. Here, the effects of NANT in inhibiting recombinant PHD2 and up-regulating of HIF-1 and HIF-1-mediated carboanhydrase-9 (CA9) mRNA expression were compared in living cells with the NO donors N-nitrosomelatonin (NOMela) and S-nitrosoglutathione (GSNO) under normoxic and hypoxic conditions. In contrast to GSNO, NANT was similar to NOMela being highly effective in inhibiting recombinant PHD2. NANT-mediated activation of HIF-1 in oxygenated cells was comparable to hypoxic activation of HIF-1 in all cases. In contrast, under hypoxia NANT was able to boost hypoxic cellular HIF-1 levels by further reducing the activity of cellular PHD2. The strong increase of HIF-dependent CA9 mRNA expression demonstrated that NANT-induced HIF-1 was transcriptionally active. Finally, the efficacy of NANT to increase both HIF-1 and CA9 mRNA did not depend on the absolute conformation of the tryptophan moiety. In conclusion, NANT appears to be an excellent NO donor for cells in culture and l-NANT should be useful for in vivo animal studies.
Laboratory Study of Soft Soil Improvement using Lime Mortar-(Well Graded) Soil Columns
Authors: Malekpoor Mohammad Reza , Toufigh Mohammad Mohsen
Published: March 2010

Stone columns and sand compaction piles represent the most known column-type technique for improving soft soils. In this study, more than 675 laboratory tests were carried out on composite specimens with lime mortar-well graded soil (lime-WS) column. These tests were conducted on specimens prepared as lime-WS using a mixture of lime and well graded soil poured into a local clay soil material with various proportions of lime and different curing times. The test programs were designed to investigate influences of variations in the moisture content on composite specimens. All tests were performed on specimens based on the classical California bearing ratio (CBR) testing procedure according to ASTM D1883–94. Test results were used to train an artificial neural network (ANN). ANN makes it possible to predict the behavior of these columns and their load bearing capacity as a function of changes in clay and lime content with different curing times. Tests results show that lime-WS columns, which contain 20 % lime and 22 % clay, increase the strength of soft fine grained soils to a noticeable amount.
Culturally-Sensitive Information-Sharing in Pediatric Palliative Care
Authors: Davies Betty , Contro Nancy , Larson Judith , Widger Kimberley
Published: March 2010

OBJECTIVES:

This study aimed to learn about experiences of Mexican American and Chinese American families who require pediatric palliative care. This article describes parents' perceptions of information-sharing by health care providers during their child's hospitalizations and at their child's death.

METHODS:

The study used a retrospective design of grounded theory analysis. Participants included 36 parents (26 Mexican American and 10 Chinese American) from 28 families who experienced between 6 months and 5 years before study participation the death of a child who was aged ≤20 years. Participants were recruited through 2 university hospitals in northern California.

RESULTS:

Parents' identified 3 types of information shared by health care providers: (1) information about the child's daily life in hospital; (2) information about the parents' daily life in hospital; and (3) information about treatment and end-of-life issues. Parents' narratives focused primarily on information shared by physicians; nurses, social workers, chaplains, interpreters, and other parents were also important sources of information. Four patterns of information-sharing emerged: (1) no information; (2) basic information; (3) basic information plus implications; and (4) basic information plus implications plus attention to parents' questions, concerns, and emotions. Positive and negative impacts of these patterns on parents are described.

CONCLUSIONS:

Language and cultural differences create barriers to information-sharing by health care providers to parents who are in need of pediatric palliative care. Less than optimal patterns of information-sharing contribute to frustration, anger, and sadness for parents long after their child's death.
Widespread Vitamin D Deficiency in Urban Massachusetts Newborns and Their Mothers
Authors: Merewood Anne , Mehta Supriya D. , Grossman Xena , Chen Tai C. , Mathieu Jeffrey S. , Holick Michael F. , Bauchner Howard
Published: March 2010

OBJECTIVE:

To determine vitamin D status and associated factors in a cohort of newly delivered infants and their mothers in Boston, Massachusetts.

PATIENTS AND METHODS:

Enrollment in this cross-sectional study took place from 2005 to 2007 in an urban Boston teaching hospital with 2500 births per year. A questionnaire and medical-record data were used to identify variables that are potentially associated with vitamin D deficiency (25-hydroxyvitamin D [25(OH)D] < 20 ng/mL). Infant and maternal blood was obtained by venipuncture within 72 hours of birth. The main outcome measure was infant and maternal 25(OH)D status, assessed by competitive protein binding.

RESULTS:

We enrolled 459 healthy mother/infant pairs. After subsequent exclusions, analyses were performed on 376 newborns and 433 women. The median infant 25(OH)D level was 17.2 ng/mL (95% confidence interval [CI]: 16.0–18.8; range: <5.0 to 60.8 ng/mL). The median maternal 25(OH)D level was 24.8 ng/mL (95% CI: 23.2–25.8; range: <5.0 to 79.2 ng/mL). Overall, 58.0% of the infants and 35.8% of the mothers were vitamin D deficient (25[OH]D < 20 ng/mL); 38.0% of the infants and 23.1% of the mothers were severely deficient (25[OH]D < 15 ng/mL). Risk factors for infant vitamin D deficiency included maternal deficiency (adjusted odds ratio [aOR]: 5.28 [95% CI: 2.90–9.62]), winter birth (aOR: 3.86 [95% CI: 1.74–8.55]), black race (aOR: 3.36 [95% CI: 1.37–8.25]), and a maternal BMI of ≥35 (aOR: 2.78 [95% CI: 1.18–6.55]). Maternal prenatal-vitamin use throughout the second and third trimesters was protective against infant deficiency (aOR: 0.30 [95% CI: 0.16–0.56]). Similarly, prenatal-vitamin use of ≥5 times per week in the third trimester was protective for mothers (aOR: 0.37 [95% CI: 0.20–0.69]). Despite this, >30% of the women who took prenatal vitamins were still vitamin D deficient at the time of birth.

CONCLUSIONS:

A high proportion of infants and their mothers in New England were vitamin D deficient. Prenatal vitamins may not contain enough vitamin D to ensure replete status at the time of birth.
Travelling of persons needing medical control; tourist travelling with chronic kidney insufficiency
Authors: Fenyves Judit
Published: March 2010

Felkai Péter dr.
az
Orvosi Hetilap
hasábjain és több tudományos igényű dolgozatban is említést tesz a biztosítási orvostan ismeretének fontosságáról – igaz, hogy nem utazási, hanem orvosi szemszögből nézve [1, 2, 3, 4]. Ezt a kérdéskört jelen írásomban magam az utazási oldalról közelítem meg, remélve, hogy több honfitársunknak is segíthetünk a várva várt utazásának zökkenőmentes – egészségi állapotának megőrzését is jelentő – biztosításában. Alábbi munkámban a krónikus veseelégtelenségben szenvedők turistakénti utazásával foglalkozom részletesebben, kitérve arra, milyen körülmények között lehetséges számukra csoportos utazásuk megszervezése úgy, hogy az utazás alatt mindazon egészségügyi és orvosi ellátást megkaphassák, amelyekre életfunkcióik biztosításához egészségkárosodásuk miatt az utazás alatt is szükségük van.
Degradation Mechanism of GaN-based LEDs With Different Growth Parameters
Authors: Ka Kuen Leung , Fong W.K. Patrick , Chan Paddy Kwok Leung , Surya Charles
Published: March 2010

We investigated the degradation mechanism of GaN LEDs due to the application of a high d.c. stressing current. To identify the underlying process for device failure we examined the effects of the InGaN quantum well growth parameters on the hot-electron hardness of the devices. Systematic characterizations on the degradations in the microstructural, thermoreflectance, and low frequency noise properties of the devices were performed.
Structural and Magnetic Properties of Zn1-xCoxO Nanoparticles Prepared by a Simple Sol-Gel Method at Low Temperature
Authors: Jáuregui-Rosas Segundo R. , Perales-Perez Oscar , Urcia-Romero S. , Asmat-Uceda M. , Quezada-Castillo E.
Published: March 2010

Pure and Zn1-xCoxO nanoparticles have been synthesized by a simple sol-gel method at low temperature where neither a chelating agent nor subsequent annealing was required. The effect of Cobalt atomic fraction, ‘x’ ≤ 0.0625, on the structural and magnetic properties of the doped ZnO powders was evaluated. X-ray diffraction and Fourier-transform infrared spectroscopy analyses evidenced the exclusive formation of the ZnO-wurtzite structure; no isolated Co-phases were detected. The linear dependence of cell parameters a and c with ‘x’, suggested the actual replacement of Zn by Co ions in the oxide lattice. Micro Raman spectroscopy measurements showed a band centered at 534cm-1, which can be assigned to a local vibrational mode related to Co species, in addition to the normal modes associated with wurtzite. The intensity and broadening of this band at 534 cm-1 were enhanced by increasing ‘x’. In turn, the other bands corresponding to A1 (E2, E1) and E2High modes were red shifted at higher Co contents. Room-temperature magnetization measurements revealed the paramagnetic behavior of the Co-doped ZnO nanoparticles.
Interactions between Single-Walled Carbon Nanotubes (SWNT) and Ciliates: SWNT Interfere with Ciliate Ecological Functions and Ciliates Transport/Transform SWNT
Authors: Chan Tiffany S. Y. , Nasser Fatima , St-Denis Christine H. , Bols Niels C. , Tang Shirley
Published: March 2010

We investigated the interactions of water soluble single-walled carbon nanotubes (SWNT) with unicellular organisms, in particular a ciliated protozoan (Tetrahymena thermophila) and a bacteria (Escherichia coli), which are common constituents of natural fresh water. The ciliates could effectively incorporate SWNT into natural organic matter (NOM), and therefore into normal ecological processes. Further, SWNT induced the ciliates to egest viable bacteria in membrane-enclosed vesicles. The egested bacteria aggregates had escaped digestion by the protozoan and were able to proliferate and resist antibiotic/disinfectant treatments, which may have important implications to public health. This work highlights the importance of studies on nanoparticle ecotoxicology.
Exciton Nonlinearities and Optical Gain in Colloidal CdSe/CdS Dot/rod Nanocrystals
Authors: Saba Michele , Marceddu Marco , Quochi Francesco , Minniberger Stefan , Roither Jürgen , Gocalinska Agnieszka , Kovalenko Maksym V , Talapin Dmitri V , Heiss Wolfgang , Mura Andrea , Bongiovanni Giovanni
Published: March 2010

We characterized the optical nonlinearities of CdSe nanocrystals surrounded by rod-like CdS shells with ultrafast measurements of time-resolved photoluminescence. We measured the exciton-exciton interaction to be, depending on structure details, attractive or repulsive, by as much as 29 meV, due to the unique band alignment in the CdSe/CdS. This feature makes CdSe/CdS dot/rods promising gain media for solution-processable lasers, as it appears combined with 80% photoluminescence quantum yield, narrow size and shape distributions and the antenna effect of the CdS rod shell enhancing optical absorption by more than a factor 50 with respect to bare dots.
SERS Study of Alizarin Red Dye on Colloidal Silver Nanoparticles
Authors: Swarnkar Raj Kumar , Singh Subhash Chandra , Gopal Ram
Published: March 2010

The present paper deals with surface enhanced Raman scattering (SERS) study of an organic dye Alizarin Red on colloidal silver nanoparticles. The colloidal solution of nanoparticles is synthesized by pulsed laser ablation of silver rod in pure deionized water using focused out put of 1064nm wavelength of Nd:YAG laser having 35mJ/ pulse energy. Sodium chloride is used as aggregating agents. It is observed that SERS enhancement factor varies strongly depending on concentration of used aggregating agent (especially on the concentration of Cl- ions). These changes in SERS efficiency of colloid are reflected through changes on the absorption spectra. The possible mechanism of SERS is also discussed.
Defective nucleolar localization and dominant interfering properties of a parafibromin L95P missense mutant causing the hyperparathyroidism–jaw tumor syndrome
Authors: Panicker Leelamma M , Zhang Jian-Hua , Dagur Pradeep K , Gastinger Matthew J , Simonds William F
Published: March 2010

The hyperparathyroidism–jaw tumor syndrome (HPT–JT) is a familial cancer syndrome that can result from germline inactivation of HRPT2/CDC73, a putative tumor suppressor gene that encodes parafibromin, a component of the transcriptional regulatory PAF1 complex with homology to the yeast protein Cdc73p. The vast majority of HRPT2/CDC73 germline mutations identified have been truncation or frameshift mutations, and loss of function due to missense mutation is rare. We report here a kindred with HPT–JT due to a germline L95P missense mutation in parafibromin. The mutant parafibromin was studied in vitro to understand the basis of its presumed loss-of-function. When transfected in cultured cells, the L95P mutant was expressed to a lower level than wild-type (wt) parafibromin, a difference that was not overcome by inhibition of the proteasomal degradation pathway. The L95P mutant parafibromin retained the ability to assemble with endogenous PAF1 complex components as evidenced by co-immunoprecipitation. Analysis of subcellular localization showed that the L95P mutant was markedly deficient in nucleolar localization compared to the wt, an impairment likely resulting from disruption of a putative nucleolar localization signal immediately upstream of the L95P mutation. Transfection of the L95P parafibromin mutant, but not the wt, enhanced cell cycle progression and increased cell survival in NIH-3T3 and HEK 293 cells, resulting apparently from dominant interference with endogenous parafibromin action. The simultaneous loss of nucleolar localization and acquisition of a growth stimulatory phenotype with the L95P mutation raise the possibility that parafibromin must interact with targets in the nucleolus to fully execute its tumor suppressor functions.
Inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity and of Ras farnesylation mediate antitumor effects of anandamide in human breast cancer cells
Authors: Laezza Chiara , Malfitano Anna Maria , Proto Maria Chiara , Esposito Iolanda , Gazzerro Patrizia , Formisano Pietro , Pisanti Simona , Santoro Antonietta , Caruso Maria Gabriella , Bifulco Maurizio
Published: March 2010

The endocannabinoid system regulates cell proliferation in human breast cancer cells. Recently, we described that a metabolically stable anandamide analog, 2-methyl-2′-F-anandamide, by activation of CB1 receptors significantly inhibited cell proliferation of human breast cancer cell lines. In this study, we observed that the activation of the CB1 receptor, in two human mammary carcinoma cell lines, MDA-MB-231 and MCF7, caused the inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase activity due to a reduction of HMG-CoA reductase transcript levels. The decrease of HMG-CoA reductase activity induced the inhibition of the prenylation of proteins, in particular of the farnesylation of Ras oncogenic protein involved in cell proliferation of these cell lines. We suggest that the inhibitory effect of anandamide analog on tumor cell proliferation could be related to the inhibition of Ras farnesylation.
The role of spatial dynamics in the stability, resilience, and productivity of an estuarine fish population
Authors: Kerr L. A. , Cadrin S. X. , Secor D. H.
Published: March 2010

Understanding mechanisms that support long‐term persistence of populations and sustainability of productive fisheries is a priority in fisheries management. Complex spatial structure within populations is increasingly viewed as a result of a plastic behavioral response that can have consequences for the dynamics of a population. We incorporated spatial structure and environmental forcing into a population model to examine the consequences for population stability (coefficient of variation of spawning‐stock biomass), resilience (time to recover from disturbance), and productivity (spawning‐stock biomass). White perch (Morone americana) served as a model species that exhibits simultaneous occurrence of migratory and resident groups within a population. We evaluated the role that contingents (behavioral groups within populations that exhibit divergent life histories) play in mitigating population responses to unfavorable environmental conditions. We used age‐structured models that incorporated contingent‐specific vital rates to simulate population dynamics of white perch in a sub‐estuary of Chesapeake Bay, USA. The dynamics of the population were most sensitive to the proportion of individuals within each contingent and to a lesser degree to the level of correlation in recruitment between contingents in their responses to the environment. Increased representation of the dispersive contingent within populations resulted in increased productivity and resilience, but decreased stability. Empirical evidence from the Patuxent River white perch population was consistent with these findings. A high negative correlation in resident and dispersive contingent recruitment dynamics resulted in increased productivity and stability, with little effect on resilience. With high positive correlation between contingent recruitments, the model showed similar responses in population productivity and resilience, but decreased stability. Because contingent structure involves differing patterns of nursery habitat use, spatial management that conserves sets of habitats rather than the single most productive nursery habitat would be expected to contribute to long‐term population stability.
Forecasting the dynamics of a coastal fishery species using a coupled climate–population model
Authors: Hare Jonathan A. , Alexander Michael A. , Fogarty Michael J. , Williams Erik H. , Scott James D.
Published: March 2010

Marine fisheries management strives to maintain sustainable populations while allowing exploitation. However, well‐intentioned management plans may not meet this balance as most do not include the effect of climate change. Ocean temperatures are expected to increase through the 21st century, which will have far‐reaching and complex impacts on marine fisheries. To begin to quantify these impacts for one coastal fishery along the east coast of the United States, we develop a coupled climate–population model for Atlantic croaker (Micropogonias undulatus). The model is based on a mechanistic hypothesis: recruitment is determined by temperature‐driven, overwinter mortality of juveniles in their estuarine habitats. Temperature forecasts were obtained from 14 general circulation models simulating three CO2emission scenarios. An ensemble‐based approach was used in which a multimodel average was calculated for a given CO2emission scenario to forecast the response of the population. The coupled model indicates that both exploitation and climate change significantly affect abundance and distribution of Atlantic croaker. At current levels of fishing, the average (2010–2100) spawning biomass of the population is forecast to increase by 60–100%. Similarly, the center of the population is forecast to shift 50–100 km northward. A yield analysis, which is used to calculate benchmarks for fishery management, indicates that the maximum sustainable yield will increase by 30–100%. Our results demonstrate that climate effects on fisheries must be identified, understood, and incorporated into the scientific advice provided to managers if sustainable exploitation is to be achieved in a changing climate.
Habitat degradation and fishing effects on the size structure of coral reef fish communities
Authors: Wilson S. K. , Fisher R. , Pratchett M. S. , Graham N. A. J. , Dulvy N. K. , Turner R. A. , Cakacaka A. , Polunin N. V. C.
Published: March 2010

Overfishing and habitat degradation through climate change pose the greatest threats to sustainability of marine resources on coral reefs. We examined how changes in fishing pressure and benthic habitat composition influenced the size spectra of island‐scale reef fish communities in Lau, Fiji. Between 2000 and 2006 fishing pressure declined in the Lau Islands due to declining human populations and reduced demand for fresh fish. At the same time, coral cover declined and fine‐scale architectural complexity eroded due to coral bleaching and outbreaks of crown‐of‐thorns starfish, Acanthaster planci. We examined the size distribution of reef fish communities using size spectra analysis, the linearized relationship between abundance and body size class. Spatial variation in fishing pressure accounted for 31% of the variation in the slope of the size spectra in 2000, higher fishing pressure being associated with a steeper slope, which is indicative of fewer large‐bodied fish and/or more small‐bodied fish. Conversely, in 2006 spatial variation in habitat explained 53% of the variation in the size spectra slopes, and the relationship with fishing pressure was much weaker (∼12% of variation) than in 2000. Reduced cover of corals and lower structural complexity was associated with less steep size spectra slopes, primarily due to reduced abundance of fish <20 cm. Habitat degradation will compound effects of fishing on coral reefs as increased fishing reduces large‐bodied target species, while habitat loss results in fewer small‐bodied juveniles and prey that replenish stocks and provide dietary resources for predatory target species. Effective management of reef resources therefore depends on both reducing fishing pressure and maintaining processes that encourage rapid recovery of coral habitat.
Should metapopulation restoration strategies increase patch area or number of patches?
Authors: Nicol Samuel C. , Possingham Hugh P.
Published: March 2010

Managers of species that exist as metapopulations are faced with many decisions. In this paper we use a decision‐theory framework to examine a fundamental management question: Should we focus on decreasing the local extinction probability of subpopulations by increasing the size of their patch, or should metapopulation viability be improved by constructing more patches? Using a spatially implicit stochastic metapopulation model and stochastic dynamic programming (SDP), we found the optimal solution to this problem for both the finite‐ and infinite‐time horizon cases. We showed that the SDP solutions outperform a range of heuristic management strategies. The optimal strategy for a given parameter set depends heavily on metapopulation parameters, and it is difficult to make generalizations about the optimal restoration strategy a priori. Although heuristic strategies perform well in some cases, it is not possible to judge their performance until the SDP solution has been computed, and for this reason we advocate the use of SDP as a management tool in restoration. We demonstrate the use of SDP by deriving an optimal management strategy for a population of the Mount Lofty Ranges Southern Emu‐wren (Stipiturus malachurus intermedius).
Enhancing early detection of exotic pests in agricultural and forest ecosystems using an urban‐gradient framework
Authors: Colunga-Garcia Manuel , Magarey Roger A. , Haack Robert A. , Gage Stuart H. , Qi Jiaquo
Published: March 2010

Urban areas are hubs of international transport and therefore are major gateways for exotic pests. Applying an urban gradient to analyze this pathway could provide insight into the ecological processes involved in human‐mediated invasions. We defined an urban gradient for agricultural and forest ecosystems in the contiguous United States to (1) assess whether ecosystems nearer more urbanized areas were at greater risk of invasion, and (2) apply this knowledge to enhance early detection of exotic pests. We defined the gradient using the tonnage of imported products in adjacent urban areas and their distance to nearby agricultural or forest land. County‐level detection reports for 39 exotic agricultural and forest pests of major economic importance were used to characterize invasions along the gradient. We found that counties with more exotic pests were nearer the urban end of the gradient. Assuming that the exotic species we analyzed represent typical invaders, then early detection efforts directed at 21–26% of U.S. agricultural and forest land would likely be able to detect 70% of invaded counties and 90% of the selected species. Applying an urban‐gradient framework to current monitoring strategies should enhance early detection efforts of exotic pests, facilitating optimization in allocating resources to areas at greater risk of future invasions.
The Greater of Two Evils? How People With Transformative Psychotic Experiences View Psychotropic Medications
Authors: Hagen Brad F. , Nixon Gary , Peters Tracey
Published: March 2010

This article describes the results of a qualitative study with 22 participants who were originally interviewed about their experiences of the potentially transformational nature of psychotic episodes. During the interviews, however, the participants spontaneously described their experiences with taking psychotropic medications (particularly antipsychotics). Participants fell into three general groups in terms of their attitudes towards psychotropic medications: (a) those who complied with psychotropic use but felt that such use had considerable limitations, (b) those who felt that psychotropics should be used only in crisis situations, and (c) those who felt that the use of psychotropics was never justified. Overall, the majority of participants had very negative experiences with psychotropic medications, and this article presents a number of themes describing how participants felt that psychotropic medications caused them harm physically, cognitively, emotionally, and spiritually—and interfered with their eventual recovery from psychosis. Finally, this article presents themes that summarize how participants felt that mental health professionals contributed to their negative views toward taking psychotropic drugs.
Unplug—Don’t Drug: A Critical Look at the Influence of Technology on Child Behavior With an Alternative Way of Responding Other Than Evaluation and Drugging
Authors: Rowan Cris
Published: March 2010

The past decade has seen an increase in personal use of electronic technology, with childhood television and video game use similarly increasing. Critical milestones for child motor and sensory development are not being met. Simultaneously, there is an increasing incidence of childhood physical, psychological, and behavior disorders, often accompanied by the prescription of psychotropic medication. One in six children exhibit signs of poor health, mental stress, or problems at school. Exposure to an average of 8 hours per day of various forms of technology use has resulted in a physically sedentary yet chaotically stressed existence for Canadian children. The detrimental effects of technology use on critical milestones for child development are reviewed. This commentary by apediatric occupational therapist outlines issues of concern for parents, family physicians, and pediatricians related to these trends and offers a novel treatment approach: Unplug—Don’t Drug.
Modeling Thermomechanical Pulp and Paper Activated Sludge Treatment Plants to Gain Insight to the Causes of Bulking
Authors: Brault Jean‐Martin , Comeau Yves , Perrier Michel , Stuart Paul
Published: March 2010

The Activated Sludge Model No. 1 was chosen as the basis for model development and was modified to take into account the specific characteristics of pulp and paper effluents. The model was incorporated to the GPS‐X simulation environment (Hydromantis, Hamilton, Ontario, Canada) to study operating deficiencies and nutrient transformations, particularly in relation to bulking. The results show that the process of ammonification is not significant at the studied mill and that the process of phosphatification (transformation of soluble organic phosphorus into orthophosphates) seems to be related to settling problems, as indicated by the sludge volume index. The phosphatification rate and the standard oxygen‐transfer efficiency were found to decrease as the system entered a bulking state. Understanding the behavior of pulp and paper activated sludge can be improved by the incorporation of industry‐specific processes and components to comprehensive models. These models then can be used to gain insight to the causes of bulking.
Factors Affecting Landscape Occupancy by Fishers in North‐Central British Columbia
Authors: WEIR RICHARD D. , CORBOULD FRASER B.
Published: March 2010

ABSTRACT To better understand distribution and density of fishers (Martes pennanti) in industrial forests of north‐central British Columbia, Canada, we examined factors affecting the probability of a potential home range being occupied by 10 radiotagged resident fishers in the Sub‐Boreal Spruce biogeoclimatic zone between 1996 and 2000. Percentage of a home range in wetlands and recently logged (within past 12 yr) best predicted likelihood of occupancy by each fisher. Probability of a home range area being occupied by a resident fisher decreased with increasing amounts of wetlands and recent logging present in the area. We estimated that a 5% increase in wetlands or recent logging decreased the relative probability of occupancy of a potential home range by 50%. The accelerated rate of timber harvest in forests affected by mountain pine beetle (Dendroctonus ponderosae) infestations may have substantial implications for the ability of the landscape of central British Columbia to support sustainable populations of fishers.
A Comparison of Cover Pole With Standard Vegetation Monitoring Methods
Authors: DAVID TOLEDO P. , HERRICK JEFFREY E. , ABBOTT LAURIE B.
Published: March 2010

ABSTRACT  The ability of resource managers to make informed decisions regarding wildlife habitat could be improved with the use of existing data sets and the use of cost‐effective, standardized methods to simultaneously quantify vertical and horizontal cover. We characterized vegetation structure of 3 semiarid plant communities to compare cover pole measurements, standard measurements of vegetation cover, composition, height, and the proportion of the soil surface exposed by large intercanopy gaps. We propose that a more versatile and interpretable description of wildlife habitat can be generated using a line‐point intercept method together with measurements of vegetation height and the proportion of the soil surface exposed by large intercanopy gaps.
Sex‐Age Selectivity and Correlates of Capture for Winter‐Trapped White‐Tailed Deer
Authors: HILLER TIM L. , BURROUGHS JORDAN PUSATERI , CAMPA HENRY , COSGROVE MELINDA K. , RUDOLPH BRENT A. , TYRE ANDREW J.
Published: March 2010

ANDREW J. TYRE7

ABSTRACT  Despite the common use of Clover traps to capture white‐tailed deer (Odocoileus virginianus), little published information exists quantifying trap success, trap selectivity (sex‐age selection), or weather correlates of trap success. We quantified these relationships using white‐tailed deer data from 3 study sites in the Lower Peninsula of Michigan, USA, during winters 2001–2007. We captured 610 deer in 8,569 trap‐nights; pooled capture success was 0.07 deer/trap‐night, although site‐year success varied from 0.021 to 0.086. We compared sex‐age classes (fawn [pooled by sex], ad M, ad F) captured with sex‐age classes estimated to be available on each study site during each capture season. We used generalized linear mixed modeling to construct 19 a priori models to describe probability of capture success as a function of weather covariates (daily min. temp [° C], daily snowfall [cm], daily snow depth [cm]), Julian day, site, and year. General selection patterns included fawns captured more than expected and adult males captured less than expected; adult females were generally neutrally selected. The quasi‐Akaike's Information Criterion best model within our set was described by the global model without Julian day and contained all 3 weather covariates and site‐year effects. Our model provided some evidence that as daily snow depth increased, probability of capture increased; the positive effect of daily snowfall on capture probability was dependent on decreasing daily minimum temperature. Our results may be used to increase efficacy of deer capture programs by researchers and managers through informed decision‐making about when to allocate effort (e.g., if extreme winter weather conditions are predicted) and when to consider alternative methods (e.g., if capture of ad M is an objective).
A Comparison of Regression Models for Small Counts
Authors: MCDONALD TRENT L. , WHITE GARY C.
Published: March 2010

ABSTRACT  Count data with means <2 are often assumed to follow a Poisson distribution. However, in many cases these kinds of data, such as number of young fledged, are more appropriately considered to be multinomial observations due to naturally occurring upper truncation of the distribution. We evaluated the performance of several versions of multinomial regression, plus Poisson and normal regression, for analysis of count data with means <2 through Monte Carlo simulations. Simulated data mimicked observed counts of number of young fledged (0, 1, 2, or 3) by California spotted owls (Strix occidentalis occidentalis). We considered size and power of tests to detect differences among 10 levels of a categorical predictor, as well as tests for trends across 10‐year periods. We found regular regression and analysis of variance procedures based on a normal distribution to perform satisfactorily in all cases we considered, whereas failure rate of multinomial procedures was often excessively high, and the Poisson model demonstrated inappropriate test size for data where the variance/mean ratio was <1 or >1.2. Thus, managers can use simple statistical methods with which they are likely already familiar to analyze the kinds of count data we described here.
Auditor Independence in a Private Firm and Low Litigation Risk Setting
Authors: Hope Ole-Kristian , Langli John Christian
Published: March 2010

ABSTRACT: We examine the issue of auditor independence in a unique setting. Specifically, we test for auditor independence impairment among (1) private client firms, for which the risk of auditor reputation loss is lower than for publicly traded firms, and (2) in a low litigation environment (i.e., Norway) that further reduces the expected costs to the auditor associated with independence impairment. We have thus chosen a setting that gives independence impairment its best chance of being detected if it exists. Using a large sample of private Norwegian firms, we analyze whether auditors who receive higher fees are less likely to issue modified opinions. Despite the low litigation risk and the reduced reputation risk, our empirical results provide no evidence that auditors compromise their independence through fee dependence. These results are robust to controlling for the expected portion of fees, to different sample specifications, to the use of both levels and changes specifications, and to a number of sensitivity analyses.
Do Firms Incur Costs to Avoid Reducing Pre-Tax Earnings? Evidence from the Accounting for Low-Income Housing Tax Credits
Authors: Robinson Leslie A.
Published: March 2010

ABSTRACT: Examining corporate investment in low-income housing tax credits reveals that firms are willing to incur costs in order to manage the income statement classification of an expense. Accounting rules allow investors who purchase a tax benefit guarantee to amortize their equity in a real estate partnership as a tax expense, rather than as an operating expense, thus avoiding a reduction in pre-tax earnings. Using confidential data from tax credit syndicators, I model the market price of a tax credit as a function of the existence of the guarantee, controlling for foreclosure risk on the underlying real estate. The results are consistent with the hypothesis that an economically significant amount of the guarantee fee is paid by corporate investors for the right to use an accounting method that avoids reductions in pre-tax earnings.