bluuebunny/crossref_metadata_2025_split huggingface dataset:
Testing predictions of a three‐species plant–soil feedback model
Authors: Kulmatiski Andrew , Heavilin Justin , Beard Karen H. 
Published: January 2011

Summary 1. A growing number of experiments measure plant growth on soils cultivated by different species. Models show that the resulting plant–soil feedbacks (PSFs) can determine plant abundance and persistence; yet, quantitative tests of their importance in community dynamics are lacking. 2. Here, we use the growth of eight plant species on ‘self’ and ‘other’ soils to parameterize a three‐species PSF model. Predictions from the parameterized model were compared to plant growth observed in a 3‐month glasshouse experiment. Four types of three‐species communities were simulated: native, non‐native, nitrogen‐fixing and non‐nitrogen‐fixing. Because the PSF model is founded on a competition model, removing PSF effects from the model allowed us to compare PSF model predictions to competition model predictions. 3. Mean plant biomass differed among soil types by 20% and differed among plant species by 101%. 4. The PSF model correctly predicted rank abundance in the four communities tested while the competition model correctly predicted rank abundance in the two communities with nitrogen‐fixing plants. Furthermore, PSF model predictions of species abundances were closer to observed values than competition model predictions. Despite consistently improving upon the competition model, predictions from the PSF model were significantly different from observed values for three of four communities. Competition model predictions were different from observed values for all four communities. 5. Our three‐species model described the plant and soil conditions that allow coexistence and competitive exclusion, but when parameterized with experimental data, no communities were predicted to result in long‐term coexistence. 6.
Synthesis. Results suggest that PSFs captured a mechanism of plant community development. However, because improvements in model predictions were consistently small, either PSFs were not a dominant mechanism determining plant community development or PSFs were underestimated by our experimental or modelling approaches. Further testing of PSFs and development of improved methods to measure PSFs are suggested.
Invasive legumes fix N2 at high rates in riparian areas of an N‐saturated, agricultural catchment
Authors: Drake D. C. 
Published: January 2011

Summary 1. This study examined the seemingly paradoxical proliferation of invasive, N2‐fixing broom (Cytisus scoparius) and gorse (Ulex europaeus) in N‐saturated riparian areas of intensive agricultural land in Canterbury, New Zealand. 2. A field study of natural abundance δ15N suggested that broom and gorse along the Selwyn River fix approximately three times more N than they take up from soils, and are thus a potentially large source of N in the landscape. Broom N fixation rates based on mass balance calculations from a glasshouse study were similar. 3. In the controlled glasshouse study, broom grown at both c. 1× and 6.5× field NO3− supply fixed N at the same rate per unit biomass (0.061 mg N day−1 g−1 dry wt) over a 9‐month period. Broom plants grown under the high‐N supply, however, grew c. 1.6 times larger, and thus fixed more N per plant. Above‐to‐below‐ground biomass ratios and %N in above‐ and below‐ground pools were the same under the two levels of N supply. 4. Each broom plant in the greenhouse study contributed at least 0.02 g N year−1 to soils, but leaching from the soils was surprisingly low (<2% of total plant and soil stocks) suggesting that plants less than 1 year old are not contributing substantially to high NO3− concentrations in Selwyn ground and surface water. 5. Synthesis. This study shows that both broom and gorse growing in the Selwyn riparian area are an additional source of bioactive N in this N‐saturated ecosystem. Additionally, broom grows more quickly as N availability increases and therefore fixes more N per plant. This suggests a positive feedback whereby agricultural nutrient pollution leads to increased per‐plant N2 fixation in broom, and probably in gorse, given the taxonomic and physiological similarity of the species. The Selwyn is representative of a large number of New Zealand rivers with riparian zones that are dominated by invasive N2 fixers. The likelihood that these invasive plants increase the amount of bioactive N in rivers and downstream ecosystems presents new considerations and challenges for management.
Subcontinental impacts of an invasive tree disease on forest structure and dynamics
Authors: Garnas Jeffrey R. , Ayres Matthew P. , Liebhold Andrew M. , Evans Celia 
Published: January 2011

Summary1. Introduced pests and pathogens are a major source of disturbance to ecosystems world‐wide. The famous examples have produced dramatic reductions in host abundance, including virtual extirpation, but most introductions have more subtle impacts that are hard to quantify but are potentially at least as important due to the pathogens’ effects on host reproduction, competitive ability and stress tolerance. A general outcome could be reduced host abundance with concomitant increases in the abundance of competitors.2. Beech bark disease (BBD) is a widespread, fatal affliction of American beech (Fagus grandifolia), currently present inc. 50% of beech’s distribution in eastern North America. Despite high adult mortality, beech remains a dominant component of the forest community.3. Employing spatially extensive data from the national Forest Inventory and Analysis program of the United States Forest Service, we show that forests have changed dramatically in the presence of BBD. Within the 2.3 million km2range of beech, size‐specific mortality was 65% higher in the longest‐infected regions, and large beech (>90 cm diameter at breast height) have declined fromc. 79 individuals km−2to being virtually absent. Small stem beech density was dramatically higher (>350%) such that infested forests contain a roughly equivalent cross‐sectional (basal) area of beech as before BBD.4. There was no evidence for compensation by sugar maple or other co‐occurring tree species via increased recruitment or adult survivorship at the landscape scale. Overall, community composition remained roughly unchanged as a result of BBD.5. Surprisingly, trajectory of stand dynamics (shifts in stem density and mean tree size reflecting normal stand maturation (self‐thinning) or retrogression (more abundant, smaller trees over time)) did not differ between affected and unaffected regions. Variance in stand dynamics was greater in afflicted forests, however, indicating that predictability of forest structure has been diminished by BBD.6. Synthesis.Forests of eastern North America have shifted to increased density and dramatically smaller stature – without notable change in tree species composition – following the invasion of a novel forest disease. Our results reinforce the conclusion that introduced diseases alter fundamental properties of ecosystems, but indicate that the spectrum of potential effects is broader than generally appreciated.
Arabidopsis genes IRREGULAR XYLEM (IRX15) and IRX15L encode DUF579‐containing proteins that are essential for normal xylan deposition in the secondary cell wall
Authors: Brown David , Wightman Raymond , Zhang Zhinong , Gomez Leonardo D. , Atanassov Ivan , Bukowski John‐Paul , Tryfona Theodora , McQueen‐Mason Simon J. , Dupree Paul , Turner Simon 
Published: January 2011

SummaryThere are 10 genes in the Arabidopsis genome that contain a domain described in the Pfam database as domain of unknown function 579 (DUF579). Although DUF579 is widely distributed in eukaryotic species, there is no direct experimental evidence to assign a function to it. Five of the 10 Arabidopsis DUF579 family members are co‐expressed with marker genes for secondary cell wall formation. Plants in which two closely related members of the DUF579 family have been disrupted by T‐DNA insertions contain less xylose in the secondary cell wall as a result of decreased xylan content, and exhibit mildly distorted xylem vessels. Consequently we have named these genes IRREGULAR XYLEM 15 (IRX15) and IRX15L. These mutant plants exhibit many features of previously described xylan synthesis mutants, such as the replacement of glucuronic acid side chains with methylglucuronic acid side chains. By contrast, immunostaining of xylan and transmission electron microscopy (TEM) reveals that the walls of these irx15 irx15l double mutants are disorganized, compared with the wild type or other previously described xylan mutants, and exhibit dramatic increases in the quantity of sugar released in cell wall digestibility assays. Furthermore, localization studies using fluorescent fusion proteins label both the Golgi and also an unknown intracellular compartment. These data are consistent with irx15 and irx15l defining a new class of genes involved in xylan biosynthesis. How these genes function during xylan biosynthesis and deposition is discussed.
Daily survival and human blood index of major malaria vectors associated with oil palm cultivation in Cameroon and their role in malaria transmission
Authors: Tanga M. C. , Ngundu W. I. , Tchouassi P.D. 
Published: January 2011

SummaryObjective  To describe the daily survival rate, biting habits, feeding behaviour, sporozoite and entomological inoculation rates of Anopheles species and their relative contribution to Plasmodium falciparum transmission in large‐scale oil palm–growing zones in Cameroon.Methods  Entomological surveys by employing human‐landing catches, both indoors and outdoors, two nights per month for 12 months from October 2004.Results  A total of 2485 Anopheles were collected and four species recorded: An. funestus, An. hancocki, An. gambiae s.s. and An. nili. There was substantial indoors to outdoors variation and seasonality in the distribution of the Anopheles population. All four species showed similar nocturnal biting patterns and were sympatrically involved in malaria transmission simultaneously or replacing each other seasonally. Their constant presence throughout the year and longevity suggest that transmission can occur at any time if parasite reservoirs are present in the area. The circumsporozoite protein rates were 5.8%, 6.3%, 8.4% and 4.1%; mean anthropophilic rates were 97.1%, 94.5%, 73.9% and 77.6%, respectively, for An. funestus, An. gambiae s.l, An. nili and An. hancocki. The annual entomological inoculation rate was 1077 infectious bites per person. Of those An. gambiae specimens testing positive for P. falciparum sporozoites, 69.01% were M form and 30.99% were S form.Conclusion  Any vector control strategy intending to significantly reduce the malaria burden in the palm estate will have to take into account entomological heterogeneity in addition to ecological and socio‐economic multiplicity.
Prevalences of and risk factors for vulvar diseases in Nepal: a hospital‐based study
Authors: Pathak Deeptara , Agrawal Sudha , Dhali Tapan K. 
Published: January 2011

AbstractBackground  The vulvar diseases are common skin conditions, but their frequency and importance are often underestimated.Objectives  This study is aimed to investigate the frequency and clinical patterns of vulvar diseases and the risk factors associated with these diseases in patients attending a tertiary care hospital in eastern Nepal.Methods  Patients with vulval symptoms or cutaneous lesions on the vulva were enrolled in the study. Laboratory investigations were carried out according to need. Equal numbers of age‐matched females without vulval lesions or symptoms were selected from the outpatient department as controls.Results  Of 5521 female patients attending the Dermatology Department’s outpatient clinic during the study period, 105 (1.9%) had vulval symptoms and/or lesions. The most common types of vulvar disease were vulvar dermatoses (62.85%), pruritus vulvae (36.19%) and vulvodynia (0.95%). In vulvar dermatoses, infection was the most common (33.4%) manifestation, with a predominance of vulvovaginal candidiasis. Other dermatoses included: cysts and tumors (5.6%); pigmentary changes (vitiligo) (5.6%); inflammatory dermatoses (6.6%); atrophic vaginitis (1.8%); erosive disease (0.9%); and dermatosis caused by sexual abuse (1.9%). Use of nylon undergarments, occasional detergent use for washing clothes, and an irregular menstrual history were found to be associated with vulvar diseases.Conclusions  Our study findings indicate that the known frequency of vulvar diseases may represent only a small proportion of actual frequency. Further clinical and population‐based research should be carried out with respect to the treatment, follow‐up, and true prevalence of these diseases in the community.
Sexual precocity in hypomelanosis of Ito: mosaicism‐associated case report and literature review
Authors: Park Jin Mo , Kim Hee Jung , Kim Taegyun , Chae Hyun Wook , Kim Duk Hee , Lee Min‐Geol 
Published: January 2011

AbstractBackground  Hypomelanosis of Ito (HI), a neurocutaneous disorder characterized by hypopigmented skin lesions along Blaschko’s line with multiple accompanying diseases, may occasionally present with sexual precocity.Methods  We reviewed cases of HI with sexual precocity reported in the literature and focused on collecting information on other associated organ abnormalities, chromosomal karyotype, and type of sexual precocity. We also present our own case report.Results  Five children with sexual precocity in HI were studied. All patients were full‐term females without significant family history. Their ages ranged from three years to 11 years. Skin lesions involved the trunk and limbs. Developmental delay was present in all patients. Central nervous system involvement was found in four patients. Craniofacial abnormalities were present in four patients. Eye involvement was present in two patients. Limb abnormalities (brachydactyly and clinodactyly) were present in two patients. Skeletal organ involvement was present in three patients. Other skin lesions were present in three patients. Dental abnormalities occurred in one patient. Of the five patients, four demonstrated a peripheral type of sexual precocity, and one presented with central type sexual precocity. Vaginal bleeding was present in two patients. Chromosomal karyotype abnormalities were found in two patients, and mosaicism was present in one of these.Conclusions  Hypomelanosis of Ito is a syndrome characterized by cutaneous signs frequently associated with nervous, ocular, and musculoskeletal system abnormalities. Although it is rarely reported in conjunction with HI, physicians should recognize sexual precocity as a possible associated symptom.
Evaluation of educational methods in dermatology and confidence levels: a national survey of UK medical students
Authors: Chiang Yi Zhen , Tan Kian Tjon , Chiang Yi Ning , Burge Susan M. , Griffiths Christopher E. M. , Verbov Julian L. 
Published: January 2011

AbstractBackground  The high prevalence of skin conditions makes dermatology education an essential part of the undergraduate medical curriculum. The aim of this study was to assess the impact of different educational methods on confidence levels in dermatology among UK medical students.Methods  A survey‐based study was carried out to establish: (i) educational experience in dermatology, and (ii) confidence levels in the British Association of Dermatologists core curriculum learning outcomes. Measures of confidence were rated using a five‐point Likert scale.Results  Completed questionnaires were obtained from 449 final‐year medical students at 14 medical schools (12.9% of 3485 final‐year UK medical students). Students who received teaching from dermatologists (P ≤ 0.01), dermatology specialist nurses (P ≤ 0.001), and expert patients (P ≤ 0.001) reported higher levels of confidence. Learning in clinical settings (P ≤ 0.001) and small‐group settings (P ≤ 0.001) was associated with higher confidence levels. Student‐selected components in dermatology were associated with higher confidence levels (P ≤ 0.001). Confidence levels were consistently lower in dermatological emergencies compared with chronic conditions, reflecting the lack of clinical exposure. Overall, 64.9% of students were at least adequately confident in assessing, and 52.0% were similarly confident in managing patients with skin conditions.Conclusions  The findings of this study show that specialist clinical experiences and small‐group learning had the most significant influence on confidence levels in dermatology. Many medical students nearing qualification were less than adequately confident in their abilities to assess and manage skin conditions, suggesting that a greater emphasis on dermatology is required.
BRAF, HRAS, KRAS, NRAS and CDKN2A genes analysis in cultured melanocytes used for vitiligo treatment
Authors: Czajkowski Rafal 
Published: January 2011

AbstractBackground  Cultured pigment cells are increasingly being used in the treatment of stable vitiligo. The melanocyte growth media contain synthetic and human recombinant mitogenic factors. High concentration of growth factors, increased melanin biosynthesis, and the rapid cell cycle progression may lead to the genetic material damage and the initiation of melanocyte malignant transformation in cell culture conditions. Mutations of genes of the RAS/RAF/MEK/ERK signaling pathway and CDKN2A gene are often found in the early stages of melanoma development. 12‐O‐Tetradecanoyl‐phorbol‐13‐acetate (TPA)/phorbol 12‐myristate 13‐acetate (PMA) is considered to be an oncogenic factor, but there is no evidence that it is responsible for melanomagenesis initiation. The goal of this research was to assess the risk of the development of mutations in selected genes of the RAS/RAF/MEK/ERK signaling pathway and CDKN2A gene during the culturing of pigment cells in various growth media.Methods  Three‐hundred melanocyte cultures were established in 10 various growth media. The population doubling time of cultured cells was calculated for all the tested growth media. Cytogenetic analysis was carried out on the HRAS (exon 1 and 2), KRAS (exon 1 and 2), NRAS (exon 1 and 2), BRAF (exon 11 and 15), and CDKN2A (exon 1) genes.Results  Our study revealed that TPA and high concentrations of other growth factors intensify the proliferation of pigment cells, without the risk of damage to the analyzed genes.Conclusions  It is necessary to carry out further similar studies on other signaling pathways to confirm cultured melanocytes transplantation safety.
Ingrown nails and pachyonychia of the great toes impair lower limb functions: improvement of limb dysfunction by medical foot care
Authors: Imai Akiko , Takayama Kaoru , Satoh Takahiro , Katoh Takuro , Yokozeki Hiroo 
Published: January 2011

AbstractBackground  Painful feet and lower limb dysfunction are risk factors for falling. Toenail deformities are common disorders in elderly people, but the relationship between nail deformities and lower limb function remains unclear. The aims of the present study were to assess the impairment of lower limb function in patients with deformities of the great toe and to determine whether foot care treatment is beneficial in reducing the risk of falling.Methods  Functional tests of the lower extremities were performed in 263 adults, including patients with any of hallux valgus, ingrown nail, or pachyonychia, and volunteers. Fifty‐five subjects with nail disorders of the great toe received medical foot care treatment.Results  The presence of ingrown nail, pachyonychia, or tenderness of the great toe was significantly correlated with impaired postural performance and reduced muscular strength as assessed by functional tests. Medical foot care markedly reduced pain levels in the great toe and improved scores on functional tests of the lower extremities.Conclusions  Toenail disorders of the great toe cause dysfunction of the lower extremities and are likely to increase the risk of falling in daily life. Foot care management of toenail disorders has the potential to improve functional abilities in daily life, particularly in elderly individuals.
Resveratrol protects quail hepatocytes against heat stress: modulation of the Nrf2 transcription factor and heat shock proteins
Authors: Sahin K. , Orhan C. , Akdemir F. , Tuzcu M. , Iben C. , Sahin N. 
Published: January 2011

SummaryIn the present study, the effects of dietary resveratrol on the induction of heat shock proteins, transcription factors and antioxidative enzyme system in liver of quails under heat stress were investigated. A total of 180 (55‐day‐old) female Japanese quails (Coturnix coturnix japonica) were reared either at 22 °C for 24 h/day (thermoneutral, TN) or 34 °C for 8 h/day (heat stress, HS; 09:00–17:00 hours) for 12 weeks. Birds in both environments were randomly fed one of three diets: basal diet and basal diet added with either 200 or 400 mg of resveratrol per kg of diet. The results showed that exposure to high ambient temperature induced decreases in feed intake, egg production, and hepatic superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH‐Px) activities but increases in hepatic malondialdehyde (MDA) concentrations (p < 0.001). Liver Hsp70, Hsp90 and NF‐κB expression was greater while Nrf2 expression was lower for quails reared under the heat stress than for those reared under the TN environment (p < 0.0001). There were linear increases in feed intake, egg production, hepatic SOD, CAT, and GSH‐Px activities as well as Nrf2 expression, but linear decreases in hepatic MDA concentrations and Hsp70, Hsp90, and NF‐κB expressions with increasing supplemental resveratrol level (p < 0.0001). Two‐way treatment interactions revealed that the degree of restorations in all response variables was more notable under the high ambient temperature than that of the TN environment as dietary resveratrol concentration was increased. The results of the present study suggest that supplemental resveratrol reduces oxidative stress in heat‐stressed quails through modulating the hepatic heat shock proteins and nuclear transcription factors.
Identification of plasma and hepatic parameters related to metabolic robustness in dairy cows
Authors: Graber M. , Kohler S. , Müller A. , Burgermeister K. , Kaufmann T. , Bruckmaier R. M. , van Dorland H. A. 
Published: January 2011

SummaryBlood plasma and hepatic parameters were identified that describe the differences between metabolically robust or vulnerable dairy cows grouped according to their past health status. Data from a field study on dairy cows were used from which metabolically challenged dairy cows were selected that had a milk fat percentage of >4.5 mg/g and a fat to protein ratio of >1.5 in their previous early lactation. The selected cows were either classified as metabolically robust or vulnerable based on the occurrence of various metabolic and (re)production disorders in their previous lactations. Blood and liver tissue samples were collected in week 3 ante partum (a.p.) (−3wk), in week 4 (+4wk) and in week 13 (+13wk) post‐partum (p.p.). Plasma concentrations of metabolites and hormones and mRNA expression of genes involved in metabolic pathways in the liver were used as variables for a two‐group discriminant analysis (DA). Average discriminant scores (centroids) were different (p < 0.05) in −3wk, +4wk and in +13wk. In −3wk, significant variables that best explained the differences between metabolically robust and vulnerable cows were parity, plasma triglycerides, glucose and mRNA abundance of carnitine palmitoyltransferase 2 (CPT2). In addition, based on the classification matrix, 69% of the dairy cows were correctly classified. In +4wk, identified significant parameters were parity, plasma glucose and urea, and 67% of the cows were correctly classified. In +13wk, significant variables that explained the differences between the groups were parity, mRNA abundance of acyl‐CoA synthetase long‐chain 1 and CPT1, and 66% of the cows were correctly classified. In conclusion, the identified variables may distinguish from metabolically challenged cows, those cows that had a poorer health performance in their previous lactations.