bluuebunny/crossref_metadata_2025_split huggingface dataset:
Census and monitoring based on individually identifiable vocalizations: the role of neural networks
Authors: Terry Andrew M. R. , McGregor Peter K. 
Published: July 2002

AbstractVocal individuality is widely suggested as a method for identifying individuals within a population. But few studies have explored its performance in real or simulated conservation situations. Here we simulated the use of vocal individuality to monitor the calling corncrake (Crex crex), a secretive and endangered land rail. Our data set contained 600 calls from 30 individuals and was used to simulate a population of corncrakes being counted and monitored. We tested three different neural network models for their ability to discriminate between and to identify individuals. Neural networks are non‐linear classification tools widely applied to both biological and non‐biological identification tasks. Backpropagation and probabilistic neural networks were used to simulate the reidentification of members of a known population (monitoring) and a Kohonen network was used to simulate the counting of a population of unknown size (census). We found that both backpropagation and probabilistic networks identified all individuals correctly all the time, irrespective of sample size. Kohonen networks were more variable in performance but estimated population size to within one individual of the actual size. Our results indicate that neural networks can be used effectively together with recordings of vocalizations in census and monitoring tasks.
The use of photographic rates to estimate densities of cryptic mammals: response to Jennelle et al.
Authors: Carbone C. , Christie S. , Conforti K. , Coulson T. , Franklin N. , Ginsberg J. R. , Griffiths M. , Holden J. , Kinnaird M. , Laidlaw R. , Lynam A. , MacDonald D. W. , Martyr D. , McDougal C. , Nath L. , O'Brien T. , Seidensticker J. , Smith J. L. D. , Tilson R. , Wan Shahruddin W.N. 
Published: July 2002

AbstractMost species‐specific conservation efforts require estimates of population size to establish priorities and to monitor management activities. Yet obtaining reliable estimates of animal populations is often difficult, especially given time and funding limitations experienced by many research programmes. Consequently, there is a great need for practical methods to provide indices of animal density. Ideally, accurate estimates of populations would be obtained through mark‐recapture data collected from recognizable individuals over multiple censuses that cover the entire population range. Such data are rarely available, so conservation biologists have no alternative but to resort to analyses of less perfect data, ranging from permanent‐point censuses from cameras through to transect data on sightings and spoor encounters. The importance of census and monitoring data makes the development, and validation, of new techniques a priority. Because we do not live in a perfect world, there is a need to develop methods that can give an estimate of population sizes. It would be naïve to assume that these will give hugely accurate estimates of population size, but these techniques can prove useful in identifying areas that are likely to benefit from conservation action.
De novo MECP2 frameshift mutation in a boy with moderate mental retardation, obesity and gynaecomastia
Authors: Kleefstra T , Yntema HG , Oudakker AR , Romein T , Sistermans E , Nillessen W , Van Bokhoven H , De Vries BBA , Hamel BCJ 
Published: July 2002

Rett syndrome (RTT) is an X‐linked neurodevelopmental disorder caused by mutations in the MECP2 gene, with apparent lethality in male embryos. However, recent studies indicate that mutations in the MECP2 gene can cause congenital encephalopathy, an Angelman‐like phenotype and even nonspecific mental retardation in males.We report on a 10‐year‐old boy with moderate mental retardation, hypotonia, obesity and gynaecomastia and a de novo 2‐bp deletion in the MECP2 gene that resulted in a frameshift and premature stop codon. As some of the clinical features were suggestive of the Prader–Willi syndrome, it might be worthwhile screening for MECP2 mutations in patients with an atypical Prader–Willi phenotype but without the characteristic abnormalities on chromosome 15q.This report contributes to the phenotypic knowledge of male patients with MECP2 mutations. Moreover, this is the first reported male case of a de novo MECP2 mutation.
Hepatic Met‐enkephalin immunoreactivity is enhanced in primary biliary cirrhosis
Authors: Bergasa NV , Liau S , Homel P , Ghali V. 
Published: July 2002

Abstract:  Background/aims: In contrast to the normal adult liver, the fetal human and rat livers, and the liver of rats with cholestasis secondary to bile duct resection (BDR) express the preproenkephalin (ppENK) mRNA, which codes for the endogenous opioid peptide Met‐enkephalin. In addition, Met‐enkephalin immunoreactivity (MEIR) is detected in hepatocytes and in proliferating bile ductules in the cholestatic rat liver. These data suggest that cholestasis is associated with the resurgence of cells that produce Met‐enkephalin. To explore further the status of opioids in cholestasis, we studied the expression of MEIR in liver tissue.Methods: The MEIR was sought in paraffin‐preserved liver tissues from patients with primary biliary cirrhosis (PBC) (n = 10).Results: The MEIR was detected in all the PBC livers. Its intensity varied from weak to strong on hepatocytes and bile ducts and the strongest expression appeared as coarse granules. The MEIR was either absent or only faintly expressed by some hepatocytes from disease and nondisease control biopsies, but absent from bile ducts.Conclusion: These results suggest that the human liver in cholestasis may be a source of endogenous opioids.
Intrahepatic expression of the hepatic stellate cell marker fibroblast activation protein correlates with the degree of fibrosis in hepatitis C virus infection
Authors: Levy MT , McCaughan GW , Marinos G , Gorrell MD 
Published: July 2002

Abstract:  Background: Activated hepatic stellate cells (HSCs), recognised by their α smooth muscle actin immunoreactivity, are primarily responsible for liver fibrosis. However, the presence of α smooth muscle actin positive HSCs is not always associated with the development of liver fibrosis. Recently, other markers of human HSCs including the gelatinase fibroblast activation protein (FAP) and glial fibrillary acidic protein have been identified.Aims: We examined the relationship between the expression of these HSC markers and the severity of liver injury in patients with chronic hepatitis C virus infection.Methods: Liver tissue from 27 patients was examined using immunohistochemistry. Linear correlation analysis was used to compare staining scores with the stage and grade of liver injury.Results–Conclusions: FAP expression, seen at the tissue‐remodelling interface, was strongly and significantly correlated with the severity of liver fibrosis. A weaker correlation was seen between glial fibrillary acidic protein expression and fibrosis stage. This contrasted with the absence of a relationship between α smooth muscle actin and the fibrotic score. A correlation was also observed between FAP expression and necroinflammatory score. In summary, FAP expression identifies a HSC subpopulation at the tissue‐remodelling interface that is related to the severity of liver fibrosis.
Thrombopoietin serum levels are elevated in patients with hepatitis B/C infection compared to other causes of chronic liver disease
Authors: Schöffski Patrick , Tacke Frank , Trautwein Christian , Martin Michael Uwe , Caselitz Martin , Hecker Hartmut , Peter Manns Michael , Ganser Arnold 
Published: July 2002

Abstract:  Background/aims:  Thrombocytopenia in patients with advanced liver disease may stem from a deficient hepatic thrombopoietin production.Methods: We determined the relationship between thrombopoietin, thrombocytopenia, aetiology and extent of liver damage by incorporating serum thrombopoietin measurements in the pretransplant evaluation of 111 patients with liver disease.Results: The extent of thrombocytopenia was related to the underlying cause of disease. The platelet count directly correlated with factor V, II, fibrinogen, and PTT, and a negative correlation was found for splenic size and Child's stage. The thrombopoietin concentrations were age‐dependent, and no significant difference resulted between the median thrombopoietin level of liver disease patients with age‐matched healthy controls. Thrombopoietin concentrations and platelet counts were not correlated. Although noncirrhotic patients had higher platelet counts than those with Child's A–C cirrhosis (p < 0.001, U‐test), no such difference was found in thrombopoietin levels. Patients with hepatitis B and/or C had lower platelet counts compared to patients with nonviral diseases (p < 0.001), and their median thrombopoietin concentrations were significantly higher (p < 0.001).Conclusion: We conclude that thrombocytopenia in patients with liver disease is unlikely to be explained only based on a deficient hepatic production of thrombopoietin. Patients with chronic viral hepatitis have significantly elevated thrombopoietin levels; the involved pathomechanisms require further study.
Leptin deficiency reduces but does not eliminate the development of hepatic fibrosis in mice infected with Schistosoma mansoni
Authors: Potter James J. , Mezey Esteban 
Published: July 2002

Abstract:  Aims/Background: Leptin, a product of the obese (ob) gene, was demonstrated previously in activated hepatic collagen‐producing stellate cells, but not in quiescent retinol‐storing stellate cells. The role of leptin in fibrogenesis is unknown. This study investigated the possible influence of leptin in the pathogenesis of fibrosis by determination of the amount of fibrosis produced by Schistosoma mansoni infection in leptin deficient male ob/ob mice as compared to control mice.Methods: The mice were infected percutaneously with cercaria of Schistosoma mansoni and the amount of liver fibrosis determined 12 weeks after infection. The amount of hepatic collagen deposited was quantified by morphometric analysis of liver sections stained with sirius red and by hydroxyproline content.Results: The amount of histologically detectable fibrosis was greater in the infected controls than in the infected ob/ob mice. In the infected control mice, but not in the ob/ob mice, the fibrosis surrounding the granuloma was broad and extended beyond the portal tracts into the lobule with the formation of fibrous septa.Conclusions: This study shows that leptin is a potentiating, but not an essential factor, for the development of hepatic fibrosis, because leptin deficiency reduces but does not prevent the development of hepatic fibrosis.
Stabilized viral nucleic acids in plasma as an alternative shipping method for NAT
Authors: Lee Dong‐Hun , Li Liping , Andrus Linda , Prince Alfred M. 
Published: July 2002

BACKGROUND: Preservation of the integrity of viral nucleic acids in blood specimens during shipping and handling is crucial for NAT and viral load monitoring. An economical and convenient method is described for nucleic acid stabilization by using an RNA stabilizing solution (RNAlater, Ambion) in plasma that is designed for the shipment of samples to tropical countries.STUDY DESIGN AND METHODS: HCV, HIV, and HBV FFP were compared with RNAlater‐treated plasma and dried plasma spots (DPSs) after incubation at 37°C, which was chosen as an upper limit of ambient shipping temperature, for up to 28 days. HCV‐infected chimpanzee plasma was shipped at either room temperature after RNAlater treatment or as frozen plasma in liquid nitrogen from Liberia to New York City. They were then compared for HCV RNA levels. The nucleic acid stabilities were determined by quantitative PCR by using a molecular beacon assay on a sequence detection system (ABI 7700, PE‐Biosystems) and by visualizing the PCR components on an acrylamide gel.RESULTS: Quantitative PCR data showed that a 60:40 or greater ratio of RNAlater:plasma volume successfully stabilized HCV RNA and HIV RNA in plasma for up to 28 days at 37°C. HBV DNA in plasma was stable for up to 14 days at 37°C without any stabilizing solution. DPSs on filter paper stabilized viral nucleic acids, but the recoveries were 3 to 10 times less than those with frozen plasma. The integrity of the 5′ UTR region of HCV RNA in RNA later‐treated chimpanzee plasma was intact when its PCR component was viewed on an acrylamide gel.CONCLUSION: The DPS method stabilized nucleic acids, at least with the extraction method used, was less sensitive than use of RNAlater, and required tedious manual handling. RNAlater provides a convenient way of stabilizing viral nucleic acid in plasma at ambient temperature during sample transportation.
Lack of SCN1A Mutations in Familial Febrile Seizures
Authors: Malacarne Michela , Madia Francesca , Gennaro Elena , Vacca Daniela , Güney A. Ilter , Buono Salvatore , Bernardina Bernardo Dalla , Gaggero Roberto , Gobbi Giuseppe , Lispi Maria Luisa , Malamaci Daniela , Melideo Giustino , Roccella Maurizio , Sferro Caterina , Tiberti Alessandra , Vanadia Francesca , Vigevano Federico , Viri Franco , Vitali Maria Rosa , Bricarelli Franca Dagna , Bianchi Amedeo , Zara Federico 
Published: July 2002

Summary:  Purpose: Mutations in the voltage‐gated sodium channel subunit gene SCN1A have been associated with febrile seizures (FSs) in autosomal dominant generalized epilepsy with febrile seizures plus (GEFS+) families and severe myoclonic epilepsy of infancy. The present study assessed the role of SCN1A in familial typical FSs.Methods: FS families were selected throughout a collaborative study of the Italian League Against Epilepsy. For each index case, the entire coding region of SCN1A was screened by denaturant high‐performance liquid chromatography. DNA fragments showing variant chromatograms were subsequently sequenced.Results: Thirty‐two FS families accounting for 91 affected individuals were ascertained. Mutational analysis detected a single coding variant (A3169G) on exon 16. The extended analysis of all family members and 78 normal controls demonstrated that A3169G did not contribute to the FS phenotype.Conclusions: Our study demonstrated that SCN1A is not frequently involved in common FSs and suggested the involvement of specific FS genes.
Serum Insulin and Leptin Levels in Valproate‐associated Obesity
Authors: Pylvänen Virpi , Knip Mikael , Pakarinen Arto , Kotila Mervi , Turkka Jukka , Isojärvi Jouko I. T. 
Published: July 2002

Summary:  Purpose: Weight gain is an important adverse effect of valproate (VPA) therapy, and it is associated with hyperinsulinemia and hyperandrogenism in women with epilepsy. Leptin is considered a signaling factor regulating body weight and energy metabolism. In human subjects, obesity is in general associated with elevated serum leptin levels, suggesting decreased sensitivity to leptin. The present study aimed at evaluating the role of insulin and leptin in VPA‐related obesity.Methods: Body mass index (BMI) was calculated, and serum insulin and leptin levels were measured in 81 patients with epilepsy taking VPA and in 51 healthy control subjects.Results: Forty (49%) of the patients taking VPA and 25 (49%) of the control subjects were obese. The mean insulin levels were higher in VPA‐treated patients than in the control subjects despite similar BMI values, when all subjects were included in the comparison. Both obese male and female patients taking VPA had higher serum insulin levels than the respective control subjects with similar BMI values. Serum insulin levels also were higher in lean male and lean female patients compared with the lean control subjects of same sex. Serum leptin levels did not differ between the VPA‐treated patients and the control subjects.Conclusions: Both obese and lean patients taking VPA for epilepsy have hyperinsulinemia, suggesting development of insulin resistance. This may be one of the factors leading to weight gain during VPA treatment. However, the results of the present study do not suggest an independent role for leptin in the pathogenesis of VPA‐related obesity.
Seizure Reduction and Quality of Life Improvements in People with Epilepsy
Authors: Birbeck Gretchen L. , Hays Ron D. , Cui Xinping , Vickrey Barbara G. 
Published: July 2002

Summary:  Purpose: Previous research suggests that seizure freedom may be necessary to improve health‐related quality of life (HRQOL) for epilepsy surgery patients, but little is known regarding the seizure‐frequency reduction needed to improve HRQOL among medically treated individuals.Methods: With data from 134 adults with refractory complex partial seizures participating in a randomized controlled antiepileptic drug (AED) trial, we compared the change in HRQOL across groups having different levels of change in seizure frequency: 100%, 75–99%, 50–74% reduction, and 0–50% increase or decrease. Changes over time within each seizure‐reduction group also were assessed. HRQOL was measured by the QOLIE‐31, QOLIE‐89, and SF‐36.Results: Subjects who became seizure free reported significantly more positive change than those who did not on the QOLIE‐31 and QOLIE‐89 overall scores, the QOLIE‐89 mental health, physical health, and epilepsy‐targeted composites, as well as the SF‐36 mental health summary score. Changes over time in overall QOLIE‐31 and QOLIE‐89 scores were significantly more positive for subjects who achieved seizure freedom (i.e., 100% reduction in seizure frequency) than for those who did not. No significant change in QOLIE‐31 and QOLIE‐89 overall scores was observed for subjects who did not achieve seizure freedom.Conclusions: In this study, HRQOL improvement occurred primarily among patients who achieved complete seizure freedom. Many AED trials use a 50% seizure‐frequency reduction criterion as a trial end point, but measurable impacts of this degree of reduction in seizure frequency on HRQOL in this sample were not observed. These results further support striving for seizure freedom as an epilepsy care goal.
Do Structural Properties Explain the Anticonvulsant Activity of Valproate Metabolites? A QSAR Analysis
Authors: Bello‐Ramírez Angélica M. , Carreón‐Garabito Blanca Y. , Nava‐Ocampo Alejandro A. 
Published: July 2002

Summary:  Purpose: Differences in potency among valproate (VPA) metabolites could be explained by structural properties. Therefore, a quantitative structure–activity relation (QSAR) analysis was performed to study the relation between structural parameters and the effect of the following VPA metabolites: 4‐en‐VPA, 2‐en‐VPA, 3‐en‐VPA, 2,4'‐dien‐VPA, 4,4'‐dien‐VPA, 4‐hydroxy‐VPA, 3‐ceto‐VPA, 3‐hydroxy‐VPA, 5‐hydroxy‐VPA, and propylglutaric acid.Methods: By using the CAChe program package for biomolecules (Oxford Molecular, Ltd), we performed molecular modeling. The anticonvulsant activity determined on the threshold for maximal electroconvulsions in mice was obtained from a study of Löscher and Nau. Structural parameters were compared between metabolites with a double bond and metabolites with oxygen at either side chain (unpaired Student's t test). A single linear regression analysis between each structural parameter and the relative anticonvulsant potency was also performed.Results: Similar parameters were found between the cis and trans and R and S isomers. Biologic activity and most of the structural parameters were significantly different between metabolites with a double bond and metabolites with oxygen at either side chain. Activity was directly related to log Poct (r2 = 0.77) and to reactivity parameters and was inversely related to stability parameters and to molecular weight and surface. The most potent metabolites had a log Poct value of higher than 2 units.Conclusions: Similar data were identified between cis and trans, and R and S isomers of VPA metabolites. Anticonvulsant activity was mainly related to log Poct, probably reflecting the ability of VPA metabolites to cross the blood–brain barrier.
Delayed mating reduces reproductive output of female European grapevine moth, Lobesia botrana (Lepidoptera: Tortricidae)
Authors: Torres-Vila L.M. , Rodríguez-Molina M.C. , Stockel J. 
Published: July 2002

AbstractVirgin females of Lobesia botrana Denis & Schiffermüller were mated at ages of 1, 3, 5, 8, 12 and 16 days and the effect of mating delay on reproductive output assessed. Delayed mating did not affect female mating success but fertilization was reduced in 16-day-old females. Increased mating delays substantially affected daily oviposition pattern and resulted in a significant reduction of both fecundity and fertility, so that mean number of viable eggs laid decreased from 150 to 22 in 1- and 16-day-old mated females, respectively. Heavier females were more constrained than lighter ones by mating delays and female reproductive efficiency (no. viable eggs/female body weight) was also significantly reduced. Female longevity significantly increased and oviposition period gradually declined with mating delay. The number of viable eggs was positively correlated with both female weight and oviposition period; female longevity and female weight were also significantly correlated. However, the significance of these correlations declined with increased mating delay. Results overall indicated that mating delay drastically reduces female L. botrana reproductive output. The implications of delayed mating of females are discussed from an ecological perspective in relation to L. botrana control using mating disruption.
Modelled impact of insecticide-contaminated dung on the abundance and distribution of dung fauna
Authors: Vale G.A. , Grant I.F. 
Published: July 2002

AbstractDeterministic models assessed the effects that contaminated dung from insecticide-treated cattle had on populations of three hypothetical species of dung fauna that dispersed randomly and could double their numbers every 1–28 weeks at low density. Insecticide was allowed to kill 2–98 % of adults and prevent 16–100% of breeding in pats produced immediately after cattle treatment, with toxicity declining to < 1% in pats produced 2–23 days later. Treatment intervals were 10–40 days. The modelled impact of insecticide was affected little by approximately four-fold variations in: length and density dependence of the attractive life span of pats, frequency of pat occupation by immature adults, distribution of pat toxicity during treatment interval, and changes in dispersal rates due to age and population density. Of greater importance were variations in: pat toxicity, treatment interval, frequency of pat occupation by breeding adults, density dependence of recruitment and death, natural adversity and mortality in dormancy, general rate of dispersal, and the size and shape of the area with treated cattle. Overall, it seemed that wide variations in the impact of contamination will occur in the field, but in many situations the risk to dung fauna can be substantial, especially for slow breeding beetles, and muscoids contacting insecticide on cattle. Risk extends outside the treated areas, for a distance equal to several daily displacements of the insects. Untreated refuges for species survival should be compact blocks at least 25 daily displacements wide.