bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elevated growth temperatures reduce the carbon gain of black spruce [Picea mariana (Mill.) B.S.P.]
Authors: WAY DANIELLE A. , SAGE ROWAN F. 
Published: February 2008

AbstractWe explored the effect of high‐growth temperatures on a dominant North American boreal tree, black spruce [Picea mariana (Mill.) B.S.P.]. In 2004 and 2005, we grew black spruce at either 22 °C/16 °C day/night temperatures [low temperature (LT)] or 30°/24 °C [high temperature (HT)] and determined how temperature affected growth, leaf morphology, photosynthesis, respiration and thermotolerance. HT spruce were 20% shorter, 58% lighter, and had a 58% lower root : shoot ratio than LT trees. Mortality was negligible in the LT treatment, but up to 14% of HT seedlings died by the end of the growing season. HT seedlings had a higher photosynthetic temperature optimum, but net photosynthesis at growth temperatures was 19–35% lower in HT than LT trees. HT seedlings had both a lower apparent maximum ribulose‐1,5‐bisphosphate carboxylation capacity (Vcmax) and a lower apparent maximum electron transport rate (Jmax) than LT trees, indicating reduced allocation to photosynthetic components. Consistently, HT needles had 26% lower leaf nitrogen content than LT needles. At each measurement temperature, HT seedlings had 20–25% lower respiration rates than LT trees; however, this did not compensate for reduced photosynthetic rates at growth temperature, leading to a greater ratio of dark respiration to net carbon dioxide assimilation rate in HT trees. HT needles had 16% lower concentrations of soluble sugars than LT needles, but similar starch content. Growth at high temperatures increased the thermotolerance of black spruce. HT trees showed less PSII inhibition than LT seedlings and no increase in electrolyte leakage when briefly exposed to 40–57 °C. While trees that develop at high temperatures have enhanced tolerance for brief, extreme heat events, the reduction in root allocation indicates that seedlings will be more susceptible to episodic soil drying and less competitive for belowground resources in future climates of the boreal region.
Response of wild C4 crop progenitors to subambient CO2 highlights a possible role in the origin of agriculture
Authors: CUNNIFF JENNIFER , OSBORNE COLIN P. , RIPLEY BRAD S. , CHARLES MICHAEL , JONES GLYNIS 
Published: February 2008

AbstractThe synchronous origin of agriculture in at least four independent climatic regions at the end of the last glacial period (c10 kyr bp) points to a global limitation for crop domestication. One hypothesis proposes that a rapid carbon dioxide (CO2) increase from 18 Pa to ∼27 Pa during deglaciation caused significant increases in the growth rates of wild crop progenitors, thereby removing a productivity barrier to their successful domestication. However, early C4 crops present a challenge to this hypothesis, because they were among the first domesticates, but have a carbon‐concentrating mechanism that offsets the limitation of photosynthesis by CO2. We investigated the CO2‐limitation hypothesis using the wild progenitors of five C4 founder crops from four independent centres of domestication. Plants were grown in controlled environment chambers at glacial (18 Pa), postglacial (28 Pa) and current ambient (38 Pa) CO2 levels, and photosynthesis, transpiration and biomass were measured. An increase in CO2 from glacial to postglacial levels caused a significant gain in vegetative biomass of up to 40%, but the equivalent rise in CO2 from postglacial to modern levels generally had no effect on biomass. Investigation into the underlying mechanisms showed C4 photosynthesis to be limited more by glacial than postglacial CO2 levels, matching theoretical expectations. Moreover, the increase in CO2 from glacial to postglacial levels caused a reduction in the transpiration rate via decreases in stomatal conductance of ∼35%. In combination, these physiological changes conferred a large improvement in water‐use efficiency at the postglacial CO2 partial pressure compared with the glacial level. Our data, therefore, provide experimental support for the CO2‐limitation hypothesis, suggesting that these key physiological changes could have greatly enhanced the productivity of wild crop progenitors after deglaciation.
Soil type links microbial colonization of rice roots to methane emission
Authors: CONRAD RALF , KLOSE MELANIE , NOLL MATTHIAS , KEMNITZ DANA , BODELIER PAUL L. E. 
Published: February 2008

AbstractMost of the methane (CH4) emission from rice fields is derived from plant photosynthates, which are converted to CH4. Rice cluster I (RC‐1) archaea colonizing the rhizosphere were found to be the methanogens responsible for this process. Hence, RC‐1 methanogens seem to play a crucial role in emission of the greenhouse gas CH4. We determined the community composition and activity of methanogens colonizing the roots of eight different rice cultivars after growth on both Italian rice soil and river bank soil, which contained different communities of methanogenic archaea. The community composition was analyzed by terminal restriction fragment length polymorphism and cloning/sequencing of the archaeal 16S rRNA gene and the mcrA gene coding for a subunit of the methyl coenzyme M reductase. When grown on rice field soil, the methanogenic community of the different rice cultivars was always dominated by RC‐1 methanogens. In contrast, roots were colonized by Methanomicrobiales when grown on river bank soil, in which RC‐1 methanogens were initially not detectable. Roots colonized with Methanomicrobiales compared with RC‐1 exhibited lower CH4 production and CH4 emission rates. The results show that the type of methanogens colonizing rice roots has a potentially important impact on the global CH4 cycle.
Simulated climate change provokes rapid genetic change in the Mediterranean shrub Fumana thymifolia
Authors: JUMP ALISTAIR S. , PEÑUELAS JOSEP , RICO LAURA , RAMALLO ELISENDA , ESTIARTE MARC , MARTÍNEZ‐IZQUIERDO JOSÉ A. , LLORET FRANCISCO 
Published: February 2008

AbstractRapid climate change will impose strong directional selection pressures on natural plant populations. Climate‐linked genetic variation in natural populations indicates that an evolutionary response is possible. We investigated such a response by comparing individuals subjected to elevated drought and warming treatments with individuals establishing in an unmanipulated climate within the same population. We report that reduction in seedling establishment in response to climate manipulations is nonrandom and results from the selection pressure imposed by artificially warmed and droughted conditions. When compared against control samples, high single‐locus genetic divergence occurred in drought and warming treatment samples, with genetic differentiation up to 37 times higher than background (mean neutral locus) genetic differentiation. These loci violate assumptions of selective neutrality, indicating the signature of natural selection by drought. Our results demonstrate that rapid evolution in response to climate change may be widespread in natural populations, based on genetic variation already present within the population.
Fine root dynamics in a loblolly pine forest are influenced by free‐air‐CO2‐enrichment: a six‐year‐minirhizotron study
Authors: PRITCHARD SETH G. , STRAND ALLAN E. , McCORMACK M. LUKE , DAVIS MICHEAL A. , FINZI ADRIEN C. , JACKSON ROBERT B. , MATAMALA ROSER , ROGERS HUGO H. , OREN RAM 
Published: February 2008

AbstractEfforts to characterize carbon (C) cycling among atmosphere, forest canopy, and soil C pools are hindered by poorly quantified fine root dynamics. We characterized the influence of free‐air‐CO2‐enrichment (ambient +200 ppm) on fine roots for a period of 6 years (Autumn 1998 through Autumn 2004) in an 18‐year‐old loblolly pine (Pinus taeda) plantation near Durham, NC, USA using minirhizotrons. Root production and mortality were synchronous processes that peaked most years during spring and early summer. Seasonality of fine root production and mortality was not influenced by atmospheric CO2availability. Averaged over all 6 years of the study, CO2enrichment increased average fine root standing crop (+23%), annual root length production (+25%), and annual root length mortality (+36%). Larger increase in mortality compared with production with CO2enrichment is explained by shorter average fine root lifespans in elevated plots (500 days) compared with controls (574 days). The effects of CO2‐enrichment on fine root proliferation tended to shift from shallow (0–15 cm) to deeper soil depths (15–30) with increasing duration of the study. Diameters of fine roots were initially increased by CO2‐enrichment but this effect diminished over time. Averaged over 6 years, annual fine root NPP was estimated to be 163 g dw m−2 yr−1in CO2‐enriched plots and 130 g dw m−2 yr−1in control plots (P= 0.13) corresponding to an average annual additional input of fine root biomass to soil of 33 g m−2 yr−1in CO2‐enriched plots. A lack of consistent CO2× year effects suggest that the positive effects of CO2enrichment on fine root growth persisted 6 years following minirhizotron tube installation (8 years following initiation of the CO2fumigation). Although CO2‐enrichment contributed to extra flow of C into soil in this experiment, the magnitude of the effect was small suggesting only modest potential for fine root processes to directly contribute to soil C storage in south‐eastern pine forests.
Increased night temperature reduces the stimulatory effect of elevated carbon dioxide concentration on methane emission from rice paddy soil
Authors: CHENG WEIGUO , SAKAI HIDEMITSU , HARTLEY ANNE , YAGI KAZUYUKI , HASEGAWA TOSHIHIRO 
Published: February 2008

AbstractTo determine how elevated night temperature interacts with carbon dioxide concentration ([CO2]) to affect methane (CH4) emission from rice paddy soil, we conducted a pot experiment using four controlled‐environment chambers and imposed a combination of two [CO2] levels (ambient: 380 ppm; elevated: 680 ppm) and two night temperatures (22 and 32 °C). The day temperature was maintained at 32 °C. Rice (cv. IR72) plants were grown outside until the early‐reproductive growth stage and then transferred to the chambers. After onset of the treatment, day and night CH4 fluxes were measured every week. The CH4 fluxes changed significantly with the growth stage, with the largest fluxes occurring around the heading stage in all treatments. The total CH4 emission during the treatment period was significantly increased by both elevated [CO2] (P=0.03) and elevated night temperature (P<0.01). Elevated [CO2] increased CH4 emission by 3.5% and 32.2% under high and low night temperature conditions, respectively. Elevated [CO2] increased the net dry weight of rice plants by 12.7% and 38.4% under high and low night temperature conditions, respectively. These results imply that increasing night temperature reduces the stimulatory effect of elevated [CO2] on both CH4 emission and rice growth. The CH4 emission during the day was larger than at night even under the high‐night‐temperature treatment (i.e. a constant temperature all day). This difference became larger after the heading stage. We observed significant correlations between the night respiration and daily CH4 flux (P<0.01). These results suggest that net plant photosynthesis contributes greatly to CH4 emission and that increasing night temperature reduces the stimulatory effect of elevated [CO2] on CH4 emission from rice paddy soil.
The co effect of prophylaxis and radiosynovectomy on bleeding episodes in haemophilic synovitis
Authors: BRECELJ J. , BOLE V. , BENEDIK‐DOLNIČAR M. , GRMEK M. 
Published: February 2008

Summary.  Prophylactic substitution treatment and radiosynoviorthosis have a leading role in preventing irreversible haemophilic arthropathy. The aim of the study was to evaluate the effects of prophylaxis treatment and radiosynovectomy on the length of intervals between subsequent haemorrhages in haemophilic patients. Thirty‐three joints were treated with radiosynovectomy in 28 patients with bleeding disorders. 90Y colloid was used in knees and 186Re colloid for elbows, shoulders and ankles. Twenty patients were on prophylaxis. Joint X‐rays were evaluated on the Pettersson scale between 0 (normal) and 13 (severe joint destruction). During an observation period (range 6–44 months) bleeding episodes were recorded and data statistically analysed. Before radiosynovectomy, increasing intensity of the prophylaxis 10% lengthens intervals between two haemorrhages by 1% (P < 0.05). In patients with a Pettersson score higher than nine, intervals between bleedings are shorter by 73% (P < 0.05), in comparison with patients with lower Pettersson scores of 0–5. After radiosynovectomy, the length of the first non‐bleeding interval increased by 120% (to 60 days) in comparison with the intervals before the procedure (P < 0.001). But, in the following year and half, every subsequent non‐bleeding interval was 8% shorter (P < 0.1). In that period, prophylaxis shortened the non‐bleeding interval by 1.7% (P < 0.05) per 10% increase of its intensity. Radiosynovectomy is more efficient in patients with less affected joints and is less efficient in younger patients. Prophylaxis reduced time between the bleedings episodes after isotope application. Before radiosynovectomy, prophylaxis reduces the number of haemorrhages. Our findings support data previously published by Rodriguez‐Merchan et al. [J Thromb Haemost, 5 (2007) P‐W‐126].
Membrane loss and aberrant nuclear localization of E‐cadherin are consistent features of solid pseudopapillary tumour of the pancreas. An immunohistochemical study using two antibodies recognizing different domains of the E‐cadherin molecule
Authors: Chetty R , Serra S 
Published: February 2008

Aim:  To examine the expression of E‐cadherin in solid pseudopapillary tumours (SPT) of the pancreas using two monoclonal antibodies recognizing two different domains of the E‐cadherin molecule.Methods and results:  Twenty cases of SPT were collected and a tissue microarray (TMA) constructed. The TMA was stained with commercially available antibodies to E‐cadherin and β‐catenin. All 20 cases displayed nuclear β‐catenin as well as aberrant E‐cadherin expression. With the antibody that stains the cytoplasmic domain of E‐cadherin (clone 36, BD Transduction Laboratories), all 20 cases demonstrated nuclear E‐cadherin reactivity, whereas with use of the antibody that recognizes the extracellular domain (clone 36B5, Vector Laboratories), no reactivity was observed in any of the cases.Conclusion:  This study shows that aberrant β‐catenin and E‐cadherin protein expression occurs in 100% of SPT, is probably linked mechanistically to β‐catenin nuclear localization, and two distinct patterns of E‐cadherin immunoreactivity are seen in SPT: nuclear (with the antibody against the cytoplasmic domain), or immunonegativity (complete loss) when stained with the antibody for the E‐cadherin extracellular fragment.
Natural history and clearance of HPV after treatment of precancerous cervical lesions
Authors: Aerssens A , Claeys P , Garcia A , Sturtewagen Y , Velasquez R , Vanden Broeck D , Vansteelandt S , Temmerman M , Cuvelier C A 
Published: February 2008

Aim: To assess the clearance rate of human papillomavirus (HPV) after out‐patient treatment of cervical intraepithelial neoplasia (CIN).Methods and results: A total of 122 Nicaraguan women with HPV DNA‐positive and histologically confirmed CIN lesions were included in the study. Fifty‐five patients with CIN1 and 67 with CIN2–3 were treated by cryotherapy and loop electrosurgical excision procedure (LEEP), respectively. Follow‐up visits were scheduled at 6 weeks, 6 months, 1 year and 2 years. Investigations included cytology, HPV DNA testing and colposcopy/biopsy if needed. The clearance rate of HPV was calculated by multivariate logistic regression. Immediately after treatment, a pronounced decrease in presence of HPV was observed in both groups, with a significantly higher clearance in the LEEP group than in the cryotherapy group (P = 0.019). Subsequently, clearance continued over time and was similar between the cryotherapy group and the LEEP group (P = 0.73). Approximately the same detection rates were obtained for persistence of all HPV types and for high‐risk types separately: 43.9, 37.6, 29.9 and 17.7% in the cryotherapy group and 24.9, 20.3, 15.3 and 8.4% in the LEEP group at 6 weeks, 6 months, 1 year and 2 years, respectively.Conclusions: Out‐patient treatment of precancerous lesions of the cervix usually results in clearance of HPV. Both LEEP and cryotherapy are highly effective methods of eradicating HPV. HPV DNA testing may have added value in the follow‐up of patients.
Distribution of infectious pancreatic necrosis virus (IPNV) in wild marine fish from Scottish waters with respect to clinically infected aquaculture sites producing Atlantic salmon, Salmo salar L.
Authors: Wallace I S , Gregory A , Murray A G , Munro E S , Raynard R S 
Published: February 2008

AbstractThis study represents the first large‐scale investigation of IPNV in Scottish wild marine fish. Kidney samples were taken from 30 627 fish comprising 37 species and 45 isolations were made from nine different species, illustrating these as reservoirs of IPNV in Scottish waters. The estimated prevalence of IPNV in the Scottish marine environment was low at 0.15% (90% confidence intervals, (CI) of 0.11–0.19%). This was significantly greater in fish caught less than 5.0 km from IPN‐positive fish farms in Shetland, at 0.58% (90% CI of 0.45–0.77%). This prevalence persisted and did not significantly decrease over the 16‐month period of study. The estimated prevalence of IPNV for each positive species was less than 1% with the statistically non‐significant exceptions of flounder, Platichthys flesus (L.), at 12.5% (90% CI of 0.64–47.06%) and saithe, Pollachius virens (L.), at 1.11% (90% CI of 0.49–2.19%). The 45 isolates were titrated and all but two were below the detection limit of the test (<55 PFU g−1). Titres of 3.8 × 102 PFU g−1 and 2.8 × 101 PFU g−1 were calculated from common dab, Limanda limanda (L.), and saithe, respectively. This study provides evidence that clinical outbreaks of IPN in farmed Atlantic salmon may cause a localized small increase in the prevalence of IPNV in wild marine fish.
A comparison between non‐destructive and destructive testing of Atlantic salmon, Salmo salar L., broodfish for IPNV – destructive testing is still the best at time of maturation
Authors: Munro E S , Ellis A E 
Published: February 2008

AbstractTwo populations of Atlantic salmon broodstock, previously identified as infectious pancreatic necrosis virus (IPNV) carriers, were screened for IPNV at the time of stripping. Four hundred and ten broodfish were individually sampled of which 91 were detected as IPNV positive by virus culture of sonicated kidney homogenates combined with gonadal fluid, but none tested positive by the blood leucocyte assay. Thirty fish identified as IPNV carriers prior to maturation by the blood leucocyte assay were used in a separate study to compare non‐destructive vs. destructive testing methods at stripping. IPNV was not detected using the blood leucocyte method at the time of stripping. RT‐PCR and real‐time PCR assays failed to detect IPNV from 13 blood samples, the virus was not isolated from milt (0/14) or sonicated ovarian fluid cell pellets (0/16) and only three fish tested positive by the standard culture of kidney homogenates. A third study of Atlantic salmon broodfish compared the IPNV isolation rates prior to maturation with the isolation rates at spawning during 1999–2001. In each year the percentage of IPNV‐positive broodfish was significantly lower than in the pre‐broodstock sample. While in pre‐broodfish samples IPNV was detected by the blood leucocyte assay, no culture isolations or PCR positives were detected from non‐destructive samples of the same individual broodfish at stripping. A consistent finding was that even for the kidney assay, the percentage of IPNV‐positive fish in carrier populations was higher in pre‐broodstock than in broodfish at stripping. These results indicate that destructive kidney sampling is still the most sensitive method for detecting IPNV carrier Atlantic salmon broodfish and that a change in IPNV carrier‐status occurs during the maturation period.
Characterization of swim bladder non‐inflation (SBN) in angelfish, Pterophyllum scalare (Schultz), and the effect of exposure to methylene blue
Authors: Perlberg S T , Diamant A , Ofir R , Zilberg D 
Published: February 2008

AbstractFailure to inflate the swim bladder is regarded a major obstacle in the rearing of many fish species. We present a study of swim bladder non‐inflation (SBN) in angelfish, Pterophyllum scalare. A normal developing primordial swim bladder was first discernable at the end of the first day post‐hatch (p.h.) as a cluster of epithelial cells with a central lumen, surrounded by presumably mesenchymal cells. Initial inflation occurred on the fourth day p.h. Prior to inflation the swim bladder epithelium consisted of an outer squamous and inner columnar layer. Cells of the inner layer were filled at their basal region with an amorphous material, which disappeared upon inflation. A pneumatic duct was absent, and larvae presented no need to reach the water surface for inflation, suggesting that angelfish are pure physoclists. A model for the role of the amorphous material in normal initial inflation is proposed. Abnormal swim bladders were apparent from the fourth day p.h., and methylene blue (MB) at a concentration of 5 ppm significantly increased the prevalence of SBN. Histologically, abnormal swim bladders in larvae hatched in 5 ppm MB could not be distinguished from those in fish raised under routine conditions (0.5 ppm MB). We suggest that MB may have a teratogenic effect in angelfish.
Melatonin treatment in individuals with intellectual disability and chronic insomnia: a randomized placebo‐controlled study
Authors: Braam W. , Didden R. , Smits M. , Curfs L. 
Published: February 2008

AbstractBackground While several small‐number or open‐label studies suggest that melatonin improves sleep in individuals with intellectual disabilities (ID) with chronic sleep disturbance, a larger randomized control trial is necessary to validate these promising results.Methods The effectiveness of melatonin for the treatment of chronic sleep disturbance was assessed in a randomized double‐blind placebo‐controlled trial with 51 individuals with ID. All of these individuals presented with chronic ideopatic sleep disturbance for more than 1 year. The study consisted of a 1‐week baseline, followed by 4 weeks of treatment. Parents or other caregivers recorded lights off time, sleep onset time, night waking, wake up time and epileptic seizures. Endogenous melatonin cycle was measured in saliva before and after treatment.Results Compared with placebo, melatonin significantly advanced mean sleep onset time by 34 min, decreased mean sleep latency by 29 min, increased mean total sleep time by 48 min, reduced the mean number of times the person awoke during the night by 0.4, decreased the mean duration of these night waking periods by 17 min and advanced endogenous melatonin onset at night by an average of 2.01 h. Lights off time, sleep offset time and the number of nights per week with night waking did not change. Only few minor or temporary adverse reactions and no changes in seizure frequency were reported.Conclusions Melatonin treatment improves some aspects of chronic sleep disturbance in individuals with ID.