bluuebunny/crossref_metadata_2025_split huggingface dataset:
What does dengue disease surveillance contribute to predicting and detecting outbreaks and describing trends?
Authors: Runge‐Ranzinger Silvia , Horstick Olaf , Marx Michael , Kroeger Axel 
Published: October 2008

SummaryObjective To review the evidence on the application of tools for dengue outbreak prediction/detection and trend monitoring in passive and active disease surveillance systems in order to develop recommendations for endemic countries and identify research needs.Method Systematic review of literature in the Cochrane Database of Systematic Reviews, PubMed, EMBASE, Lilacs, WHO library database, manual reference search and grey literature. Two reviewers independently applied pre‐defined inclusion and exclusion criteria and assessed the level of evidence. Studies describing the outcome of dengue disease surveillance with respect to trend monitoring and outbreak prediction/detection based on empirical data were included.Results Twenty‐four studies (of 1804 references) met the eligibility criteria. Different indicators and their respective threshold values were identified as potential triggers for outbreak alerts through retrospective analysis of data from passive and/or active surveillance systems. Some indicators are potentially useful for predicting imminent outbreaks in the low transmission season and others for detecting outbreaks at an early stage. However, the information collected is mainly retrospective and often site‐specific and appropriate levels of sensitivity and specificity of the outbreak indicators/triggers could not be determined. Retrospective and prospective virus surveillance studies were not conclusive regarding the question of whether a newly introduced serotype is an outbreak predictor, but contributed additional indicators for outbreak prediction/detection. Under‐reporting was a major concern. Taking cost and feasibility issues into account, it remains an open question whether dengue surveillance should be passive (based on routine reporting) or active (based on more costly sentinel or other active population based surveillance systems). Adding active surveillance elements to a well‐functioning passive surveillance system improves sensitivity; adding laboratory elements to the system improves specificity.Conclusions In view of the lack of evidence about the most feasible and sustainable surveillance system in a country context, countries could use a stepwise approach to locally adapt their passive routine surveillance system into an improved combined active/passive surveillance approach. Prospective studies are needed to better define the most appropriate dengue surveillance system and trigger for dengue emergency response.
Canine mast cell tumours: a review of the pathogenesis, clinical features, pathology and treatment
Authors: Welle Monika M. , Bley Carla Rohrer , Howard Judith , Rüfenacht Silvia 
Published: October 2008

AbstractMast cells (MCs) are well known for their neoplastic transformation in solitary and multiple cutaneous mast cell tumours (MCTs), as well as visceral and systemic mastocytosis. Dogs have a unique risk of developing cutaneous MCTs, and they account for 7% to 21% of all canine skin tumours. The aetiology of canine MCTs is unknown but is probably multifactorial. This article reviews up‐to‐date knowledge on the pathogenesis, the clinical presentation, the clinical prognostic factors, the diagnostic workup including clinical staging, cytological findings, histological findings and the various grading systems which have been evaluated based on morphology, the assessment of proliferation markers and other factors such as vessel density. Furthermore, detailed information about current treatment protocols for canine cutaneous MCTs is provided.
Nicotine self‐medication of cognitive‐attentional processing
Authors: Evans David E. , Drobes David J. 
Published: October 2008

ABSTRACTThis article selectively reviews research concerning nicotine's effects on cognition, including the neurobiological mechanism for these effects, task and experimental features that may be important for elucidating these effects, and why these effects may have amplified motivational significance among smokers with cognitive deficit. Nicotine has effects on various cognitive processes, though most studies in humans have focused on the amelioration of cognitive deficits experienced during drug withdrawal. The direct cognitive‐enhancing effect of nicotine remains a controversial topic. The relationship between attentional and non‐attentional cognitive effects of nicotine is discussed in the context of cognitive self‐medication. Further research should include theory‐driven examination of cognitive effects of nicotine, and develop targeted smoking cessation programs based on an improved understanding of the role of cognitive self‐medication in high‐risk individuals.
Stress, alcohol and drug interaction: an update of human research
Authors: Uhart Magdalena , Wand Gary S. 
Published: October 2008

ABSTRACTA challenging question that continues unanswered in the field of addiction is why some individuals are more vulnerable to substance use disorders than others. Numerous risk factors for alcohol and other drugs of abuse, including exposure to various forms of stress, have been identified in clinical studies. However, the neurobiological mechanisms that underlie this relationship remain unclear. Critical neurotransmitters, hormones and neurobiological sites have been recognized, which may provide the substrates that convey individual differences in vulnerability to addiction. With the advent of more sophisticated measures of brain function in humans, such as functional imaging technology, the mechanisms and neural pathways involved in the interactions between drugs of abuse, the mesocorticolimbic dopamine system and stress systems are beginning to be characterized.This review provides a neuroadaptive perspective regarding the role of the hormonal and brain stress systems in drug addiction with a focus on the changes that occur during the transition from occasional drug use to drug dependence. We also review factors that contribute to different levels of hormonal/brain stress activation, which has implications for understanding individual vulnerability to drug dependence. Ultimately, these efforts may improve our chances of designing treatment strategies that target addiction at the core of the disorder.
Developing human laboratory models of smoking lapse behavior for medication screening
Authors: McKee Sherry A. 
Published: October 2008

ABSTRACTUse of human laboratory analogues of smoking behavior can provide an efficient, cost‐effective mechanistic evaluation of a medication signal on smoking behavior, with the result of facilitating translational work in medications development. Although a number of human laboratory models exist to investigate various aspects of smoking behavior and nicotine dependence phenomena, none have yet modeled smoking lapse behavior. The first instance of smoking during a quit attempt (i.e. smoking lapse) is highly predictive of relapse and represents an important target for medications development. Focusing on an abstinence outcome is critical for medication screening as the US Food and Drug Administration approval for cessation medications is contingent on demonstrating effects on smoking abstinence. This paper outlines a three‐stage process for the development of a smoking lapse model for the purpose of medication screening. The smoking lapse paradigm models two critical features of lapse behavior: the ability to resist the first cigarette and subsequent ad libitum smoking. Within the context of the model, smokers are first exposed to known precipitants of smoking relapse (e.g. nicotine deprivation, alcohol, stress), and then presented their preferred brand of cigarettes. Their ability to resist smoking is then modeled and once smokers ‘give in’ and decide to smoke, they participate in a tobacco self‐administration session. Ongoing and completed work developing and validating these models for the purpose of medication screening is discussed.
Though with constraints imposed by endosymbiosis, preferential attachment is still a plausible mechanism responsible for the evolution of the chloroplast metabolic network
Authors: WANG Z. , ZHU X.‐G. , CHANG X. , CHEN Y. Z. , LI Y. X. , LIU L. 
Published: October 2008

AbstractChloroplasts evolved as a result of endosymbiosis, during which sophisticated mechanisms evolved to translocate nucleus‐encoded plastid‐targeted enzymes into the chloroplast to form the chloroplast metabolic network. Given the constraints and complexity of endosymbiosis, will preferential attachment still be a plausible mechanism for chloroplast metabolic network evolution? We answer this question by analysing the metabolic network properties of the chloroplast and a cyanobacterium, Synechococcus sp. WH8102 (syw). First, we found that enzymes related to more ancient pathways are more connected, and synthetases have the highest connectivity. Most of the enzymes shared by the two densest cores between the chloroplast and syw are synthetases. Second, the highly conserved functional modules mainly consist of highly connected enzymes. Finally, isozymes and enzymes from endosymbiotic gene transfer (EGT) were distributed mainly in conserved modules and showed higher connectivity than nonisozymes or non‐EGT enzymes. These results suggest that even with severe evolutionary constraints imposed by endosymbiosis, preferential attachment is still a plausible mechanism responsible for the evolution of the chloroplast metabolic network. However, the current analysis may not completely differentiate whether the chloroplast network properties reflect the evolution of the chloroplast network through preferential attachment or has been inherited from its cyanobacterial ancestor. To fully differentiate these two possibilities, further analyses of the metabolic network structure properties of organisms at various intermediate evolutionary stages between cyanobacteria and the chloroplast are needed.
Overdominant maintenance of diversity in the sea star Pisaster ochraceus
Authors: PANKEY M. S. , WARES J. P. 
Published: October 2008

AbstractWhen individuals have higher evolutionary fitness because of being heterozygous at a given gene region, it is known as overdominance. Although overdominant selection could represent an important mechanism for maintaining genetic variation within species, the prevalence of this mode of selection appears to be relatively low. Identification of cases of true single‐locus heterozygote advantage are thus useful reference points in our overall understanding of how various forms of balancing selection influence and maintain genetic variation in natural populations. Here we report the apparent long‐term maintenance of diversity via overdominant selection with homozygous lethality at an elongation factor locus in the sea star Pisaster ochraceus. Observing this pattern in a gene with such major effects on protein assembly indicates that overdominant selection could be a more prevalent factor in maintaining allelic diversity in the wild than previously recognized.
What do human economies, large islands and forest fragments reveal about the factors limiting ecosystem evolution?
Authors: LEIGH, JR E. G. , VERMEIJ G. J. , WIKELSKI M. 
Published: October 2008

AbstractWhat factors limit ecosystem evolution? Like human economies, ecosystems are arenas where agents compete for locally limiting resources. Like economies, but unlike genes, ecosystems are not units of selection. In both economies and ecosystems, productivity, diversity of occupations or species and intensity of competition presuppose interdependence among many different agents. In both, competitive dominants need abundant, varied resources, and many agents’ products or services, to support the activity and responsiveness needed to maintain dominance. Comparing different‐sized land masses suggests that productivity is lower on islands whose area is too small to maintain some of the interdependences that maintain diversity, productivity and competitiveness in mainland ecosystems. Islands lacking the rare, metabolically active dominants that make competition so intense in mainland ecosystems are more easily invaded by introduced exotics. Studies of islets in reservoirs identify mechanisms generating these phenomena. These phenomena suggest how continued fragmentation will affect future ‘natural’ ecosystems.
Non‐gelatinized starch influences the deposition of n‐3 fatty acids in the muscle of a tropical freshwater fish, Labeo rohita
Authors: Kumar V. , Sahu N. P. , Pal A. K. , Kumar S. , Sharma P. , Chettri J. K. , Sinha A. K. 
Published: October 2008

SummaryA 60‐day feeding trial was conducted to study the influence of gelatinized (G) to non‐gelatinized (NG) starch ratio in the diet on fatty acids profiles and oxidative status in Labeo rohita fingerlings. Two hundred and thirty‐four fingerlings (average weight: 2.53 g) were distributed in six treatment groups with each of three replicates. Six semi‐purified diets either containing NG and/or G corn starch (42.43%) viz., T1 (100% NG and 0% G starch), T2 (80% NG and 20% G starch), T3 (60% NG and 40% G starch), T4 (40% NG and 60% G starch), T5 (20% NG and 80% G starch) and T6 (0% NG and 100% G starch) was fed to respective groups. Catalase, superoxide dismutase and malic enzyme activities decreased linearly with the increasing level of G starch, whereas reverse trend was found for glucose‐6‐phosphate dehydrogenase. Total saturated fatty acids in muscle increased with the increasing level of G starch in the diet. Total n‐3 fatty acids decreased linearly with the increasing level of G starch in the diet. Among the n‐3 fatty acids, linolenic acids content was more in NG starch fed group. Similarly, eicosapentaenoic acid contents gradually decreased with increasing level of G starch content. The n‐6/n‐3 ratio was higher in G starch fed group. This suggests that dietary starch type may be manipulated for quality improvement of fish flesh.
Identification of Three Strains of a Virus Associated with Cassava Plants Affected by Frogskin Disease
Authors: Calvert L. A. , Cuervo M. , Lozano I. , Villareal N. , Arroyave J. 
Published: October 2008

AbstractCassava Frogskin Disease (CFSD) can cause severe damage to cassava roots and is one of the most important diseases of cassava in Latin America. The principal objective of this study was to identify the causal agent of CFSD. Electron microscopy, viral purifications, double‐stranded RNA (dsRNA) analysis, cloning, sequencing, rtPCR and hybridizations were carried out to characterize and associate a novel virus with the disease. Virus‐like particles of 70 and 45 nm in diameter were found in affected cassava plants and partially purified preparations respectively. Nine species of dsRNA were associated with this disease and cDNA clones to six genomic segments were synthesized from the purified dsRNAs. The putative proteins predicted from the sequence of the cassava virus cDNA clones have similarity with the P1, P2, P3, P4, P5 and P10 proteins of Rice ragged stunt virus (RRSV). Phylogenic analysis confirmed that this virus is a member of the family Reoviridae and is most closed related to RRSV. Hybridization analyses of dsRNA identified S1, S2, S3, S4, S5 and S10 genomic segments in the CFSD‐affected plants, but not in healthy controls. Additionally, 26 isolates were compared using a portion of the putative polymerase gene. The virus was detected in all 26 isolates, and they were classified into three distinct races. The association of this virus with CFSD was strengthened by the detection of this virus in diseased plants collected from different locations throughout Colombia.
Deep‐sea reef fish assemblage patterns on the Blake Plateau(Western North Atlantic Ocean)
Authors: Ross Steve W. , Quattrini Andrea M. 
Published: October 2008

AbstractDeep‐water coral habitats are scattered throughout slope depths (360–800 m) off the Southeastern United States (SEUS, Cape Lookout, North Carolina, to Cape Canaveral, Florida), contributing substantial structure and diversity to bottom habitats. In some areas (e.g. off North Carolina) deep corals form nearly monotypic (Lophelia pertusa) high profile mounds, and in other areas (e.g. off Florida) many species may colonize hard substrata. Deep coral and hard substrata ecosystems off the SEUS support a unique fish assemblage. Using the Johnson‐Sea‐Link submersible (in 2000–2005, 65 dives), and a remotely operated vehicle (in 2003, five dives), fishes were surveyed in nine deep reef study areas along the SEUS slope. Forty‐two benthic reef fish species occurred in deep reef habitats in these study areas. Species richness was greatest on the two coral banks off Cape Lookout, North Carolina (n = 23 and 27 species) and lowest on the two sites off Cape Canaveral, Florida (n = 7 and 8 species). Fish assemblages exhibited significantly (ANOSIM, Global R = 0.69, P = 0.001) different patterns among sites. Stations sampled off North Carolina (three study areas) formed a distinct group that differed from all dives conducted to the south. Although several species defined the fish assemblages at the North Carolina sites, Laemonema barbatulum, Laemonema melanurum, and Helicolenus dactylopterus generally had the most influence on the definition of the North Carolina group. Fish assemblages at three sites within the central survey area on the Blake Plateau were also similar to each other, and were dominated by Nezumia sclerorhynchus and L. melanurum. Synaphobranchus spp. and Neaumia sclerorhynchus differentiated the two southern sites off Cape Canaveral, Florida, from the other station groups. Combinations of depth and habitat type had the most influence on these station groups; however, explicit mechanisms contributing to the organization of these assemblages remain unclear.
Factors Affecting the Quality of Cryopreserved Buffalo (Bubalus bubalis) Bull Spermatozoa
Authors: Andrabi SMH 
Published: October 2008

ContentsStorage of buffalo (Bubalus bubalis) bull semen in the cryopreserved state is discussed in this article. Fertility rate in buffalo following artificial insemination with frozen–thawed semen is reviewed. To better understand the freezability of bubaline spermatozoa, the available data on biochemical components and the activity of specific enzymes of semen/spermatozoa are given. Moreover, the major factors that may influence the post‐thaw viability and fertility of buffalo spermatozoa are examined in detail. In addition, suggestions for improvement in cryogenic procedures for buffalo spermatozoa are also given.
EFFECT OF THE PHOSPHODIESTERASE 5 INHIBITORS SILDENAFIL, TADALAFIL AND VARDENAFIL ON RAT ANOCOCCYGEUS MUSCLE: FUNCTIONAL AND BIOCHEMICAL ASPECTS
Authors: Toque Haroldo A , Priviero Fernanda BM , Zemse Saiprasad M , Antunes Edson , Teixeira Cleber E , Webb R Clinton 
Published: October 2008

SUMMARYThe anococcygeus muscle is part of the erectile machinery in male rodents. Phosphodiesterase (PDE) 5 inhibitors enhance and prolong the effects of cGMP, which has a key role in penile erection. The aim of the present study was to provide a functional and biochemical comparison of the three PDE5 inhibitors, namely sildenafil, tadalafil and vardenafil, in the rat anococcygeus muscle.Muscle strips were mounted in 4 mL organ baths and isometric force recorded. Levels of cGMP were measured using an enzyme immunoassay kit. Western blots were used to determine PDE5 protein expression.The PDE5 inhibitors concentration‐dependently relaxed carbachol‐precontracted anococcygeus muscle; however, vardenafil was more potent (pEC50 = 8.11 ± 0.05) than sildenafil (7.72 ± 0.06) or tadalafil (7.69 ± 0.05). Addition ofNG‐nitro‐l‐arginine methyl ester (100 µmol/L) or 1H‐[1,2,4]oxadiazolo[4,3‐a]quinoxalin‐1‐one (10 µmol/L) to the organ baths caused significant rightward shifts in concentration–response curves for all PDE5 inhibitors.Sildenafil, tadalafil and vardenafil (all at 0.1 µmol/L) caused leftward shifts in the glyceryl trinitrate (GTN) concentration‐response curves (by 4.0‐, 3.7‐ and 5.5‐fold, respectively). In addition, all three PDE5 inhibitors significantly potentiated relaxation responses to both GTN (0.01–10 µmol/L) and electrical field stimulation (EFS; 1–32 Hz), with vardenafil having more pronounced effects.All three PDE5 inhibitors reduced EFS‐evoked contractions in a concentration‐dependent manner over the concentration range 0.001–1 µmol/L. There were no significant differences between the effects of the three PDE5 inhibitors.Vardenafil (0.01–0.1 µmol/L) was more potent in preventing cGMP degradationin vitrothan sildenafil (0.01–0.1 µmol/L) and tadalafil (0.01–0.1 µmol/L).Under control conditions, the expression of PDE5 was higher in the anococcygeus muscle than in the corpus cavernosum.In conclusion, PDE5 inhibitors enhance exogenous and endogenous nitric oxide‐mediated relaxation in the rat anococcygeus muscle. The potency of vardenafil was greater than that of either sildenafil or tadalafil.
MELATONIN PROTECTS AGAINST HYDROGEN PEROXIDE‐INDUCED GASTRIC INJURY IN RATS
Authors: Mohamadin Ahmed M , Ashour Osama M , El‐Sherbeny Nagla A , Alahdal Abdulrahman M , Morsy Gehan M , Abdel‐Naim Ashraf B 
Published: October 2008

SUMMARYMelatonin (MT) is a pineal hormone that is also abundant in the gut and has a well known role in scavenging oxygen free radicals. The aim of the present study was to evaluate the potential protective effects of MT against H2O2‐induced gastric lesions in rats.An experimental model of gastric ulceration was established in rats using 15% H2O2. Melatonin (12.5, 25 or 50 mg/kg, intagastrically) was administered to rats 30 min before H2O2challenge.Intragastric administration of H2O2resulted in haemorrhagic lesions in the fundic area of the stomach. Furthermore, H2O2induced gastric oxidative stress, as indicated by depletion of reduced glutathione (GSH), inhibition of glutathione peroxidase (GPx) activity and elevation of malonedialdehyde (MDA) levels. These effects were accompanied by decreased gastric tissue levels of prostaglandin (PG) E2and nitric oxide (NO), as well as increased levels of tumour necrosis factor (TNF)‐α. Administration of MT (12.5, 25 or 50 mg/kg) 30 min before H2O2significantly attenuated the development of gastric lesions in a dose‐dependent manner. The protective effects of MT were accompanied by significant inhibition of the H2O2‐induced reduction in gastric content of GSH and GPx activity and elevation in MDA levels. Furthermore, MT antagonized H2O2‐induced reduction of gastric PGE2and NO levels and elevation of TNF‐α.In conclusion, MT protects rat gastric mucosa against H2O2‐induced damage. The observed protective effects of MT can be attributed, at least in part, to its anti‐oxidant properties, preservation of PGE2and NO levels, as well as inhibition of TNF‐α induction in gastric tissues.
Crack length and stable crack extension measurements from images acquired by means of a conventional flatbed scanner
Authors: KORIN I. , LARRAINZAR C. , IPIÑA J. PEREZ 
Published: October 2008

ABSTRACTThe crack length measurements of both the original crack length and the stable crack extension are requested by several fracture toughness test methods, wherein which high accuracy measurement instruments are demanded. Low magnification optical microscopes as well as travelling‐stage microscopes are used to achieve the accuracy requirements, although many times these time‐consuming techniques present some experimental difficulties, especially when a great number of specimens have to be measured. A methodology to measure crack length from high‐resolution images acquired by means of a desktop flatbed‐scanner is presented in this paper. The acquired images are analysed by means of software that allows obtaining the crack length. Several aspects were studied to demonstrate the suitability of the method: the optical resolution, the depth of field and the effects of possible optical aberrations. Finally, an uncertainty balance was performed to demonstrate that the methodology is able to reach the necessary accuracy required by the fracture toughness test methods.