bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glial reactivity in resistance to methamphetamine‐induced neurotoxicity
Authors: Friend Danielle M. , Keefe Kristen A. 
Published: February 2013

AbstractNeurotoxic regimens of methamphetamine (METH) result in reactive microglia and astrocytes in striatum. Prior data indicate that rats with partial dopamine (DA) loss resulting from prior exposure to METH are resistant to further decreases in striatal DA when re‐exposed to METH 30 days later. Such resistant animals also do not show an activated microglia phenotype, suggesting a relation between microglial activation and METH‐induced neurotoxicity. To date, the astrocyte response in such resistance has not been examined. Thus, this study examined glial‐fibrillary acidic protein (GFAP) and CD11b protein expression in striata of animals administered saline or a neurotoxic regimen of METH on post‐natal days 60 and/or 90 (Saline:Saline, Saline:METH, METH:Saline, METH:METH). Consistent with previous work, animals experiencing acute toxicity (Saline:METH) showed both activated microglia and astocytes, whereas those resistant to the acute toxicity (METH:METH) did not show activated microglia. Interestingly, GFAP expression remained elevated in rats exposed to METH at PND60 (METH:Saline), and was not elevated further in resistant rats treated for the second time with METH (METH:METH). These data suggest that astrocytes remain reactive up to 30 days post‐METH exposure. In addition, these data indicate that astrocyte reactivity does not reflect acute, METH‐induced DA terminal toxicity, whereas microglial reactivity does.
REAL OPTIONS AND THE CROSS‐SECTION OF EXPECTED STOCK RETURNS
Authors: Guthrie Graeme 
Published: February 2013

AbstractThis paper surveys the theoretical literature investigating the effect of firms’ investment flexibility on the cross‐section of expected stock returns. Real options analysis derives firms’ value‐maximizing investment policies as functions of exogenous fundamental drivers of profitability and calculates firms’ market values as functions of the same variables. These functions yield the relationship between expected stock returns and firm fundamentals. Several plausible explanations for the value premium – the high average stock returns earned by firms with high book‐to‐market ratios – emerge from this literature.
Measuring carbon and N2 fixation in field populations of colonial and free‐living unicellular cyanobacteria using nanometer‐scale secondary ion mass spectrometry1
Authors: Foster Rachel A. , Sztejrenszus Saar , Kuypers Marcel M. M. 
Published: February 2013

Unicellular cyanobacteria are now recognized as important to the marine N and C cycles in open ocean gyres, yet there are few direct in situ measurements of their activities. Using a high‐resolution nanometer scale secondary ion mass spectrometer (nanoSIMS), single cell N2 and C fixation rates were estimated for unicellular cyanobacteria resembling N2 fixer Crocosphaera watsonii. Crocosphaera watsonii‐like cells were observed in the subtropical North Pacific gyre (22°45′ N, 158°0′ W) as 2 different phenotypes: colonial and free‐living. Colonies containing 3–242 cells per colony were observed and cell density in colonies increased with incubation time. Estimated C fixation rates were similarly high in both phenotypes and unexpectedly for unicellular cyanobacteria 85% of the colonial cells incubated during midday were also enriched in 15N above natural abundance. Highest 15N enrichment and N2 fixation rates were found in cells incubated overnight where up to 64% of the total daily fixed N in the upper surface waters was attributed to both phenotypes. The colonial cells retained newly fixed C in a sulfur‐rich matrix surrounding the cells and often cells of both phenotypes possessed areas (<1 nm) of enriched 15N and 13C resembling storage granules. The nanoSIMS imaging of the colonial cells also showed evidence for a division of N2 and C fixation activity across the colony where few individual cells (<34%) in a given colony were enriched in both 15N and 13C above the colony average. Our results provide new insights into the ecophysiology of unicellular cyanobacteria.
Wolbachia, filariae and Leishmania coinfection in dogs from a Mediterranean area
Authors: Tabar M.D. , Altet L. , Martínez V. , Roura X. 
Published: February 2013

AbstractObjectivesIn an endemic area for leishmaniosis and filariasis, coinfection can occur and the immunomodulation triggered by Wolbachia infection might influence the clinical signs and progression of both diseases. The aims of this study were to determine the prevalence of Wolbachia in dogs infected with Dirofilaria immitis and other filarial nematodes, to evaluate the prevalence of coinfection of Leishmania infantum, filariae and Wolbachia and their association with clinical presentation.MethodsPolymerase chain reaction assays were performed to detect filarial species, Wolbachia species and Leishmania in 118 samples of dogs from southeastern Spain with leishmaniosis and/or filariasis.ResultsNinety‐eight dogs were infected with Leishmania and 49 had filarial infection (29 were coinfected with both). Wolbachia DNA was detected in 30·6% of filariae‐positive dogs (15/49). Dogs coinfected with Leishmania and filaria had more severe clinical signs. Wolbachia infection was significantly (P=0·026) more frequent in dogs that were not infected with Leishmania. There was no correlation between outcome and coinfection with these pathogens.Clinical SignificanceThis study highlights the increased sensitivity of polymerase chain reaction in the diagnosis of filariasis, confirms the presence of Wolbachia in dogs from the Mediterranean basin, shows the increased severity of clinical signs when Leishmania‐filarial coinfection is present and suggests a protective role of Wolbachia in leishmaniosis.
Pharmacokinetics and Safety of Oral Administration of Meloxicam to Foals
Authors: Raidal S.L. , Edwards S. , Pippia J. , Boston R. , Noble G.K. 
Published: February 2013

BackgroundThe pharmacokinetics, efficacy, and safety of meloxicam have been evaluated in adult horses, but not foals. Physiologic differences between neonates and adults might alter drug pharmacokinetics and therapeutic index.HypothesesThe pharmacokinetics of meloxicam will be different in foals compared with adult horses, and foals could be at increased risk for adverse drug effects.AnimalsTwenty lightbreed foals less than 6 weeks of age at commencement of the study.MethodsSingle and repeated oral dose pharmacokinetics were determined for meloxicam (0.6 mg/kg) in 10 foals. The safety of the drug was further evaluated in a 2nd group of 10 foals in a randomized blinded prospective study.ResultsPlasma concentrations after a single oral dose of meloxicam (0.6 mg/kg) and time to maximum plasma concentration were similar to adult horses. However, drug clearance was much more rapid in foals (elimination half‐life 2.48 ± 0.25 hours). Administration of 0.6 mg/kg every 12 hours was well tolerated by foals for up to 3 weeks, with no evidence of drug accumulation in plasma. Adverse effects observed in adult horses at higher dose rates were not observed in foals given 1.8 mg/kg twice daily for 7 days.Conclusions and clinical importanceMeloxicam at an oral dose rate of 0.6 mg/kg every 12 hours provided plasma concentrations likely to be therapeutic. In contrast to findings for otherNSAIDs, foals appeared more resilient to the adverse effects of this drug than was observed in adult horses.
Veterinary pharmacology: history, current status and future prospects
Authors: Lees P. , Fink‐Gremmels J. , Toutain P. L. 
Published: February 2013

Veterinary therapeutics, based on the art of Materia Medica, has been practised for countless centuries, but the science of veterinary pharmacology is of very recent origin. This review traces the contribution of Materia Medica to veterinary therapeutics from the Egyptian period through to the Age of Enlightenment. The first tentative steps in the development of the science of veterinary pharmacology were taken in the 18th century, but it was not until the mid 20th century that the science replaced the art of Materia Medica. This review traces the 20th century developments in veterinary pharmacology, with emphasis on the explosion of knowledge in the 35 year period to 2010. The range of factors which have influenced the current status of the discipline are reviewed. Future developments are considered from the perspectives of what might be regarded as desirable and those innovations that might be anticipated. We end with words of encouragement for young colleagues intent upon pursuing a career in veterinary pharmacology
Which Halitholus species (Cnidaria: Hydrozoa) inhabits the Arctic and high boreal Atlantic waters?
Authors: Stepanjants Sofia , Svoboda Armin 
Published: February 2013

AbstractThe binomen Perigonimus yoldiaearcticae Birula was established (as Perigonimus yoldiae‐arcticae) for a hydroid species found predominantly on shells of the mollusk Yoldia arctica (now Portlandia arctica) in the White and Kara Seas. Its original description was incomplete, no medusa stage was described, no specific type locality was specified, and we know of the existence of no type specimens. Birula's nominal species cannot be distinguished from several other pandeids occurring at high latitudes of the northern hemisphere, and we regard P. yoldiaearcticae as a nomen dubium. By contrast, Halitholis cirratus Hartlaub, 1913 was founded on medusae obtained at Spitzbergen and in the Barents and Baltic Seas, and its presumed hydroid discovered in the Baltic (the latter a region with no other known species of pandeid medusae). We examined material referable to H. cirratus from the Kara Sea, including both medusae and hydroids (on Portlandia arctica), and conclude that this is the species inhabiting the Arctic Ocean and the high boreal Atlantic.
Autologous Pump‐Perfused Rat Hind Limb Preparation for Investigating Muscle Function and Metabolism In Vivo
Authors: Peoples Gregory E. , Hoy Andrew J. , Henry Renee , McLennan Peter L. 
Published: February 2013

AbstractObjectiveOxygen delivery, underpinned by vascular tone, is the principle limiting factor in the study of skeletal muscle physiology, particularly during muscle contraction. The aim of this study was to develop an autologous perfused rat hind limb preparation for the study of skeletal muscle contractile function.MethodsAdult Wistar rats were surgically prepared using a by‐pass system for pump‐controlled arterial blood flow to, and venous return from the hind limb during periods of quiescence and twitch contraction of the gastrocnemius‐plantaris‐soleus muscle bundle.ResultsDuring rest, hind limb perfusion pressure (102 ± 5 mmHg) was not different to systemic arterial pressure (99 ± 4 mmHg). Hind limb pressure was responsive to vasoconstrictors and vasodilators (±50 mmHg). The arterial PO2 (100 ± 3 mmHg), O2 saturation, and acid–base balance (pH: 7.42 ± 0.01) contributed to resting hind limb (a‐v)O2 difference (4.8 ± 0.5 mL/100 mL) and VO2 (0.31 ± 0.03 μmol/g/min wet weight). Repetitive isometric twitch tension (1 Hz, 0.05 ms, 10 minutes) was best maintained at a flow rate of 2 mL/min (VO2 increased fivefold during muscle contraction) and efficiency of oxygen use increased from 0.27 ± 0.08–0.52 ± 0.07 N/μmol/min.ConclusionThe autologous rat hind limb provided resting vascular tone allowing maintenance of perfusion pressure at flows within the physiological range. Oxygen delivery supported repetitive twitch contractions and facilitated measurement of active metabolism.
The Relationship between Organizational Justice and Organizational Citizenship Behaviour: The Role of Cultural Value Orientations
Authors: Schilpzand Marieke C. , Martins Luis L. , Kirkman Bradley L. , Lowe Kevin B. , Chen Zhen Xiong 
Published: February 2013

AbstractIn two studies conducted in the United States and the People's Republic of China, we examined how the effects of organizational justice perceptions on employees' organizational citizenship behaviours (OCB) are influenced by individually held cultural value orientations. In Study 1, we did not find evidence of moderation by cultural value orientation. In Study 2, we re-examined the moderated relationships and found that the relationship between procedural justice and OCB was significantly influenced by masculinity-femininity orientation and that the relationship between distributive justice and OCB was significantly moderated by power distance such that the relationships were more strongly positive when followers were more masculine and higher in power distance. Also, we extended our model to include perceived supervisor support as a mediator of the direct and moderated effects of justice perceptions on OCB. We found support for the mediation model, but did not find the moderated mediation effects we predicted. Due to the large number of non-significant findings and inconsistencies across our two studies, we conclude with recommendations for scholars who face similar challenges in their research.
Zic2 is required for enteric nervous system development and neurite outgrowth: a mouse model of enteric hyperplasia and dysplasia
Authors: Zhang Y. , Niswander L. 
Published: February 2013

AbstractFrom a forward genetic screen in mice we isolated a novel Zic2 allele with abnormal aggregation of meconium in the gastrointestinal tract. Zic2m1Nisw mutant embryos show an increase in the number of enteric neurons in vivo and disorganization of the neurite network. Explant culture of Zic2m1Nisw gastrointestinal tract show extensive neurite outgrowth, suggesting that Zic2 is a negative regulator of nerve fiber growth. These studies demonstrate a previously unknown function of Zic2 and provide a novel animal model of enteric nervous system dysplasia and hyperplasia.
Physical dormancy in seeds: a game of hide and seek?
Authors: Paulsen Torbjørn Rage , Colville Louise , Kranner Ilse , Daws Matthew I. , Högstedt Göran , Vandvik Vigdis , Thompson Ken 
Published: February 2013

Summary

Historically, ‘physical dormancy’, or ‘hard seededness’, where seeds are prevented from germinating by a water‐impermeable seed coat, is viewed as a dormancy mechanism. However, upon water uptake, resumption of metabolism leads to the unavoidable release of volatile by‐products, olfactory cues that are perceived by seed predators. Here, we examine the hypothesis that hard seeds are an anti‐predator trait that evolved in response to powerful selection by small mammal seed predators.

Seeds of two legume species with dimorphic seeds (‘hard’ and ‘soft’), Robinia pseudoacacia and Vicia sativa, were offered to desert hamsters (Phodopus roborovskii) in a series of seed removal studies examining the differences in seed harvest between hard and soft seeds. Volatile compounds emitted by dry and imbibed soft seeds were identified by headspace gas chromatography–mass spectrometry (GC‐MS).

Fourteen main volatile compounds were identified, and hamsters readily detected both buried imbibed seeds and an artificial ‘volatile cocktail’ that mimicked the scent of imbibed seeds, but could not detect buried hard or dry soft seeds.

We argue that physical dormancy has evolved to hide seeds from mammalian predators. This hypothesis also helps to explain some otherwise puzzling features of hard seeds and has implications for seed dispersal.
StInvInh2 as an inhibitor of StvacINV1 regulates the cold‐induced sweetening of potato tubers by specifically capping vacuolar invertase activity
Authors: Liu Xun , Lin Yuan , Liu Jun , Song Botao , Ou Yongbin , Zhang Huiling , Li Meng , Xie Conghua 
Published: February 2013

SummaryReducing sugar (RS) accumulation in cold‐stored potato tubers, known as cold‐induced sweetening (CIS), is a crucial factor causing unacceptable colour changes and acrylamide formation of fried products. The activity of vacuolar invertase (StvacINV1) is proved important for the CIS process, and invertase inhibitors are speculated to play roles in the post‐translational regulation of StvacINV1 activity. In our previous research, two putative inhibitors (StInvInh2A and StInvInh2B) of StvacINV1 were implied to be involved in potato CIS. Here, we further reported that StInvInh2A and StInvInh2B had similar function that specifically inhibited StvacINV1 activity in potatoes. The genetic transformation of these inhibitor genes in potatoes by overexpression in CIS‐sensitive and RNAi‐silenced in CIS‐resistant genotypes showed that StvacINV1 activity was strongly regulated by alteration of the transcripts of the inhibitors without impacting on the expression of StvacINV1. A negative power relationship was found between the transcripts of the inhibitors and StvacINV1 activity, suggesting 1) a transcriptional determination of the inhibitory capacity of StInvInh2A and StInvInh2B and 2) a significant inhibitory role of these inhibitors in post‐translational modulation of StvacINV1. The results also demonstrated that depression of StvacINV1 activity through overexpression of StInvInh2A and StInvInh2B weakened accumulation of RS and acrylamide in cold‐stored tubers and consequently improved the chip quality. The present research strongly suggest that both StInvInh2A and StInvInh2B function as inhibitors of StvacINV1 and play similar roles in regulating potato CIS by capping StvacINV1 activity. These inhibitors could be novel genetic resources applicable for improving quality of potato processing products.
Prevalence of black stain and associated risk factors in preschool Spanish children
Authors: Garcia Martin Jose Manuel , Gonzalez Garcia Manuel , Seoane Leston Juan , Llorente Pendas Santiago , Diaz Martin Juan Jose , Garcia‐Pola Maria Jose 
Published: February 2013

AbstractBackgroundIn pediatric clinical practice, it is common to be asked about the presence of black stains on teeth in children and teenagers. According to controversial etiology, it is known to be related to a low rate of caries. The aim of this study was to determine the prevalence of black stain and associated risk factors in Spanish preschool children.MethodsA total of 3272 children aged 6 years old (3058 non‐emigrant and 214 immigrant children) living in Oviedo (Spain), were enrolled in the present study.ResultsThe prevalence of black stain was 3.1% in the whole group. The index of primary decayed, missing, and filled teeth (dmft index) associated with black stain was 0.35 ± 1.123. A statistical association between black stain and the consumption of iron supplements was noted.ConclusionsThe regular consumption of foods rich in iron and the use of iron supplements during pregnancy and early childhood, could favor the development of chromogenic microbiota. The prevalence of black stain did not differ significantly between non‐emigrant and immigrant children in Spain.
Screening for Suicidal Ideation and Attempts among Emergency Department Medical Patients: Instrument and Results from the Psychiatric Emergency Research Collaboration
Authors: Allen Michael H. , Abar Beau W. , McCormick Mark , Barnes Donna H. , Haukoos Jason , Garmel Gus M. , Boudreaux Edwin D. 
Published: February 2013

Joint Commission National Patient Safety Goal 15 calls for organizations “to identify patients at risk for suicide.” Overt suicidal behavior accounts for 0.6% of emergency department (ED) visits, but incidental suicidal ideation is found in 3%–11.6%. This is the first multicenter study of suicide screening in EDs. Of 2,243 patients in six diverse emergency settings, 1,068 (47.7%) were screened with a brief instrument. Depression was endorsed by 369 (34.5%); passive suicidal ideation by 79 (7.3%); and active suicidal ideation by 24 (2.3%). One hundred thirty‐seven (12.8%) reported prior attempts, including 35 (3.3%) with current suicidal ideation. Almost half of those with current ideation had a prior attempt (43.8%) versus those without current ideation, 10.3%, χ2 (1) = 75.59, p < .001. Twenty cases (25%) were admitted to medical services, but only 10 (12.5%) received mental health assessment; none were admitted directly to a psychiatry service. The prevalence of suicidal ideation here is similar to previous studies but the frequency of prior attempts has not been reported. The 35 cases with current ideation and prior attempt are at risk. As they did not present psychiatrically, they would likely have gone undetected. Despite reporting these cases to clinical staff, few received risk assessment.
Development of MRI phantom equivalent to human tissues for 3.0‐T MRI
Authors: Hattori Kengo , Ikemoto Yusuke , Takao Wataru , Ohno Seiichiro , Harimoto Takashi , Kanazawa Susumu , Oita Masataka , Shibuya Koichi , Kuroda Masahiro , Kato Hirokazu 
Published: February 2013

Purpose:A 3.0‐T MRI phantom (called the CAGN‐3.0T phantom) having human‐equivalent relaxation times and human‐equivalent conductivity was developed.Methods:The ingredients of the phantom are carrageenan (as a gelatinizer), agarose (as a T2‐relaxation modifier), GdCl3 (as a T1‐relaxation modifier), NaCl (as a conductivity modifier), and NaN3 (as an antiseptic). Numerous samples with varying concentrations of agarose, GdCl3, and NaCl were prepared, and T1 and T2 values were measured using 3.0‐T MRI.Results:The T1 values of the CAGN‐3.0T phantom were unaffected by NaCl, while the T2 values were only slightly affected. Based on the measured data, empirical formulae were devised to express the relationships between the concentrations of agarose, GdCl3, and NaCl and the relaxation times. The formula for expressing the conductivity of the CAGN‐3.0T phantom was obtained.Conclusions:By adjustments to the concentrations of agarose, GdCl3, and NaCl, the relaxation times and conductivity of almost all types of human tissues can be simulated by CAGN‐3.0T phantoms. The phantoms have T1 values of 395–2601 ms, T2 values of 29–334 ms, and conductivity of 0.27–1.26 S/m when concentrations of agarose, GdCl3, and NaCl are varied from 0 to 2.0 w/w%, 0 to 180 μmol/kg, and 0 to 0.7 w/w%, respectively. The CAGN‐3.0T phantom has sufficient strength to replicate the torso without using reinforcing agents, and can be cut with a knife into any shape.
Virulence of Burkholderia mallei Quorum-Sensing Mutants
Authors: Majerczyk Charlotte , Kinman Loren , Han Tony , Bunt Richard , Greenberg E. Peter 
Published: February 2013

ABSTRACT

Many
Proteobacteria
use acyl-homoserine lactone-mediated quorum-sensing (QS) to activate specific sets of genes as a function of cell density. QS often controls the virulence of pathogenic species, and in fact a previous study indicated that QS was important for
Burkholderia mallei
mouse lung infections. To gain in-depth information on the role of QS in
B. mallei
virulence, we constructed and characterized a mutant of
B. mallei
strain GB8 that was unable to make acyl-homoserine lactones. The QS mutant showed virulence equal to that of its wild-type parent in an aerosol mouse infection model, and growth in macrophages was indistinguishable from that of the parent strain. Furthermore, we assessed the role of QS in
B. mallei
ATCC 23344 by constructing and characterizing a mutant strain producing AiiA, a lactonase enzyme that degrades acyl-homoserine lactones. Although acyl-homoserine lactone levels in cultures of this strain are very low, it showed full virulence. Contrary to the previous report, we conclude that QS is not required for acute
B. mallei
infections of mice. QS may be involved in some stage of chronic infections in the natural host of horses, or the QS genes may be remnants of the QS network in
B. pseudomallei
from which this host-adapted pathogen evolved.