bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of Groundwater Quality of Lokoja Basement Area, North-Central Nigeria
Authors: Ayuba R. , Omonona O. V. , Onwuka O. S. 
Published: October 2013

Abstract
The hydrochemical characteristics and quality of groundwater in Lokoja basement area have been evaluated based on different indices for assessing groundwater for drinking and irrigation purposes. Twenty groundwater samples were collected and analyzed for physicochemical parameters, major ions and heavy metals. The results revealed that the groundwater is slightly alkaline, with little variations in chemical composition. For example, electrical conductivity (EC) ranges from 242µS/cm to 1835µS/cm. The abundance of the major ions is in the order of Ca2+ &gt;Na+&gt;Mg2+&gt;K+&gt; Fe2+/3+ = HCO3 &gt;Cl- &gt;NO3 &gt;SO4 &gt;PO4. Based on the hydrochemical data, four hydrochemical facies were identified namely, Ca-Mg-HCO3, Na-K-HCO3, Na-K-Cl-SO4 and Ca-Mg-Cl-SO4 and these facies depict groundwater recharge zone, transition flow zone, deep flow zone and mixed water zone respectively. Groundwater from the area is unsuitable for drinking and domestic purposes as some of the ions and heavy metals of health concerns are well above the stipulated guideline values. Irrigation water quality indicators (salinity, Na % and Mg %), reveal that the groundwater is unsuitable for irrigation purposes. Interpreted statistical analysis reveals that the groundwater chemical compositions are controlled predominantly by weathering of litho units of the basement rocks and by drainage from domestic wastes.
Sediment Thickness Map of the Indian Region 79°E - 86E, 2°S - 8°S Based on Satellite Gravity Interpretation
Authors: Tantrigoda Dhammika A. , Fernando M. M. P. M. 
Published: October 2013

Abstract
Satellite free air gravity anomalies over the Indian ocean region 79°E - 86°E, 2°S - 8°S were obtained from the website http://topex.ucsd.edu and a contour map was compiled. Five profiles of the anomaly have been interpreted in terms of two-dimensional structures in the ocean. Thickness of sediments lying on the oceanic crust determined from the interpretation of gravity profiles were used to compile an isopach map of the region 79°E-86°E, 2°S-8°S. This map in combination with one of the isopach maps compiled by previous workers, provides information regarding the thickness of sediments up to 6° S. According to this map sediment thickness varies from ∼600 m over the middle part of the region to ∼800 m further south, indicating that thinning of sediments in the middle part of the region is only localized. Information provided by this gravity study may be useful in planning detailed seismological studies to delimit the outer edge of the continental margin of Sri Lanka, defined according to the United Nations Convention of the Law of the Sea (UNCLOS).
Breast‐Feeding and Weaning Practices in the DONALD Study
Authors: Foterek Kristina , Hilbig Annett , Alexy Ute 
Published: October 2013

ABSTRACTObjectives:Besides influencing short‐ and long‐term health status, infant feeding practices are known to have an effect on later food preferences. This study aimed to identify present trends in breast‐feeding duration and weaning practices with special focus on preparation methods of complementary food (CF), that is, homemade and commercial CF.Methods:In total, 1419 three‐day weighed diet records collected between 2004 and 2012 from 366 children of the German DOrtmund Nutritional and Anthropometric Longitudinally Designed study ages 6 to 24 months were analysed. Full (n = 339) and total breast‐feeding duration (n = 344) was collected by questionnaire. To investigate age and time trends, logistic regression and polynomial mixed regression models were used.Results:Infants born between 2008 and 2012 were 3.3‐fold less likely to be fully breast‐fed for ≥4 months than those born before 2004 (P < 0.0001). Overall, 59.3% commercial, 21.1% homemade, and 19.6% combined CF was consumed by the study sample. Subjects with high commercial CF consumption (percentage of commercial CF > median 62%) were significantly older (P < 0.0001), showed shorter full and total breast‐feeding duration (P < 0.0001), and were more likely to have mothers with a lower educational status (P = 0.01). Both commercial and homemade CF showed opposing, nonlinear age trends. No time trends could be found.Conclusions:Decreasing duration of full breast‐feeding should encourage health care providers to further promote longer breast‐feeding duration. With the constantly high consumption of commercial CF at all ages, nutritional adequacy of both homemade and commercial CF needs to be investigated closer, as does their long‐term influence on health and dietary habits, for example, fruit and vegetable intake.
Disease Activity Is an Important Factor for Indeterminate Interferon‐γ Release Assay Results in Children With Inflammatory Bowel Disease
Authors: Hradsky Ondrej , Ohem Jan , Zarubova Kristyna , Mitrova Katarina , Durilova Marianna , Kotalova Radana , Nevoral Jiri , Zemanova Ilona , Dryak Pavel , Bronsky Jiri 
Published: October 2013

ABSTRACTBackground:Interferon‐γ release assay (IGRA) is widely used for screening of latent tuberculosis (TB) before and during biological therapy (BT). An indeterminate result of IGRA represents a limitation in the management of inflammatory bowel disease (IBD). Data on factors influencing IGRA results are scarce in children. The aim of the study was to identify factors influencing IGRA results in children with IBD.Methods:Seventy‐two children with IBD (59 Crohn disease, 11 ulcerative colitis, 2 IBD‐unclassified) indicated for BT were tested for TB infection (history, TB skin test, chest radiograph, IGRA; QuantiFERON—TB Gold in tube [QFT]) and consecutively retested using QFT in 1‐year intervals.Results:We recorded 165 results of QFT (3% positive, 87% negative, and 10% indeterminate results). During follow‐up we identified 4 conversions of negative QFT to positivity (3%) and 4 reversions (4%). Patients with indeterminate results of QFT had significantly lower actual weight‐for‐height z score (P = 0.022), higher platelet count (P = 0.00017), and lower levels of serum albumin (P = 0.015) compared with patients with positive or negative QFT. Indeterminate QFT was associated with corticosteroid treatment, BT, and disease activity, but not with treatment by immunomodulators. In a subanalysis of patients with Crohn disease alone, Pediatric Crohn's Disease Activity Index was identified as single independent risk factor for indeterminate results (P = 0.00037).Conclusions:Although corticosteroid treatment is traditionally considered to be the main risk factor for indeterminate results of IGRA, the disease activity of IBD has even more profound effects on the results.
Replication Protein A2c Coupled with Replication Protein A1c Regulates Crossover Formation during Meiosis in Rice
Authors: Li Xingwang , Chang Yuxiao , Xin Xiaodong , Zhu Chunmei , Li Xianghua , Higgins James D. , Wu Changyin 
Published: October 2013

AbstractReplication protein A (RPA) is a conserved heterotrimeric protein complex comprising RPA1, RPA2, and RPA3 subunits involved in multiple DNA metabolism pathways attributable to its single-stranded DNA binding property. Unlike other species possessing a single RPA2 gene, rice (Oryza sativa) possesses three RPA2 paralogs, but their functions remain unclear. In this study, we identified RPA2c, a rice gene preferentially expressed during meiosis. A T-DNA insertional mutant (rpa2c) exhibited reduced bivalent formation, leading to chromosome nondisjunction. In rpa2c, chiasma frequency is reduced by ∼78% compared with the wild type and is accompanied by loss of the obligate chiasma. The residual ∼22% chiasmata fit a Poisson distribution, suggesting loss of crossover control. RPA2c colocalized with the meiotic cohesion subunit REC8 and the axis-associated protein PAIR2. Localization of REC8 was necessary for loading of RPA2c to the chromosomes. In addition, RPA2c partially colocalized with MER3 during late leptotene, thus indicating that RPA2c is required for class I crossover formation at a late stage of homologous recombination. Furthermore, we identified RPA1c, an RPA1 subunit with nearly overlapping distribution to RPA2c, required for ∼79% of chiasmata formation. Our results demonstrate that an RPA complex comprising RPA2c and RPA1c is required to promote meiotic crossovers in rice.
Improved protective efficacy of a chimeric Staphylococcus aureus vaccine candidate iron‐regulated surface determinant B (N126–P361)‐target of RNAIII activating protein in mice
Authors: Yu Liquan , Wang Ning , Ma Jinzhu , Tong Chunyu , Song Baifen , Chi Jiaqi , Ma Guoda , Zhu Zhanbo , Cui Yudong 
Published: October 2013

ABSTRACTThe pathogen Staphylococcus aureus causes a wide range of serious infections, necessitating urgent development of a vaccine against this organism. However, currently developed vaccines are relatively ineffective because of the limited antigenic component that is contained in the vaccine formulations. To develop an effective S. aureus candidate vaccine, overlapping PCR was used to add the truncated immunodominant antigen iron‐regulated surface determinant B (IsdB)(N126–P361) (tIsdB) to the N‐terminal of intact antigen target of RNAIII activating protein (TRAP) and thus construct a tIsdB‐TRAP chimera. The humoral and cellular immune responses against tIsdB‐TRAP were compared with those against single or combined formulations. tIsdB‐TRAP elicited significantly stronger humoral responses in mice (P < 0.05). As to cellular immune responses in mice, the tIsdB‐TRAP group resulted in a greater IL‐4 response than did other groups (P < 0.05). Greater amounts of IL‐2 and IFN‐γ were found in the tIsdB‐TRAP group. Mouse challenge also showed that tIsdB‐TRAP provided better protection against S. aureus than did the control groups. These results suggest that this chimeric protein may be a promising pathogen target for further vaccine development.
Grazing alters insect visitation networks and plant mating systems
Authors: Vanbergen Adam J. , Woodcock Ben A. , Gray Alan , Grant Fiona , Telford Annika , Lambdon Phil , Chapman Dan S. , Pywell Richard F. , Heard Matt S. , Cavers Stephen 
Published: October 2013

Summary

Many flowering plant species have a facultative or obligate dependence on insect pollination for reproductive success. Anthropogenic disturbance may alter these species interactions, but the extent to which structural changes to plant‐pollinator networks affect plant species mating systems is not well understood.

We used long‐term livestock grazing of a birch wood ecosystem to test whether disturbance of this semi‐natural habitat altered floral resources, the structure of plant–insect visitation networks and the mating system of a focal plant species, Cirsium palustre.

Grazed habitat had a higher species richness of floral resources for pollinators. Visitation networks in grazed habitats were larger, more diverse, with an increase in the number of pollinators per plant species. Controlling for sampling effects, however, showed networks in grazed habitats were less nested and revealed a positive correlation between network connectance and floral species richness.

Network connectance was negatively related to C. palustre outcrossing rate within grazed and ungrazed sites. However, on average, the effects of grazing, including greater mean connectance, produced higher overall outcrossing rates and more pollen donors compared with ungrazed habitat. The number of different pollen donors, spatial genetic structure and mating among close relatives were all correlated with greater extent of suitable C. palustre habitat in the landscape, consistent with the effects of increasing plant population size but limited seed dispersal.

Pre‐adaptation of C. palustre to disturbance coupled with a preponderance of highly dispersive flies attracted to the greater food resources in grazed habitat is a likely mechanism underpinning this increased pollen transport.

Habitat modification by long‐term mammalian grazing fundamentally shifted visitation network structure and the state of a plant mating system, indicating how ecosystem disturbance can cascade across levels of biological organization through altered interspecific interactions. Cirsium palustre retains flexibility to bias reproduction towards selfing where pollen donor diversity is limited; such reproductive flexibility may be an important mechanism structuring plant populations in human‐modified landscapes.
Adaptive maternal and paternal effects: gamete plasticity in response to parental stress
Authors: Jensen Natasha , Allen Richard M. , Marshall Dustin J. 
Published: October 2013

Summary

Transgenerational phenotypic plasticity is increasingly recognized as an important buffer of environmental change – many studies show that mothers alter the phenotype of their offspring so as to maximize their performance in their local environment. Fewer studies have examined the capacity of parents to alter the phenotype of their gametes to cope with environmental change. In organisms that shed their gametes externally, gametes are extremely vulnerable to local stresses and transgenerational plasticity in the phenotypes of gametes seems likely in this group.

In a marine tubeworm, Hydroides diramphus, we manipulated the salinity environment that mothers and fathers experienced before reproduction and then examined the phenotype of their gametes, as well as the performance of those gametes and the resultant larvae in different salinities.

We found strong evidence for gamete plasticity – both mothers and fathers adaptively adjust the phenotype of their gametes to maximize the performance of those gametes in the salinity regime experienced by their parents. Parents were quite flexible in the phenotype of gametes that they produced: they could switch the salinity tolerance of their gametes back and forth depending on their most recent experience.

Gamete plasticity was not without risks, however. We observed strong trade‐offs in performance when gametes experienced an environment that did not match that of their parents. These effects of the parental environment persist for the duration of the larval phase such that larvae may not be able to disperse to environments that do not match their parents. Gamete plasticity may therefore represent an important source of phenotype–environment mismatches.

Gamete plasticity may represent an important mechanism for coping with environmental change and an important source of maternal and paternal effects in species with external fertilization. Studies that seek to predict the impacts of stresses that persist across generations (e.g. ocean acidification) should include parental exposures to the stress of interest.
Elevated maternal temperature enhances offspring disease resistance in Daphnia magna
Authors: Garbutt Jennie S. , Scholefield Jennifer A. , Vale Pedro F. , Little Tom J. 
Published: October 2013

Summary

Maternal effects are increasingly recognized to impact upon infectious diseases. Stressful environmental conditions that coincide with high infection prevalence are potential cues for adaptive maternal effects on offspring resistance to infection.

We studied how maternal temperature (15 °C, 20 °C and 25 °C), as well as maternal food availability (high and low food) influenced the ability of the crustacean, Daphnia magna, to resist its bacterial parasite, Pasteuria ramosa.

Mothers held at a higher temperature and mothers fed a restricted diet produced offspring that were more resistant to P. ramosa infection.

Maternal temperature also influenced the progression of disease in infected offspring. Parasite spore production and host reproduction were affected by maternal temperature, but these effects differed in the two genotypes used.

As Daphnia populations experience regular summer epidemics of P. ramosa, temperature may be an environmental signal of infection risk. Thus, the enhanced resistance we observed under stressful food and temperature is conceivably an adaptation to looming epidemics.

Thus, this study identifies novel ways in which the maternal environment impacts upon disease resistance and indicates how phenotypic plasticity might both alter co‐evolution and mitigate epidemics driven by environmental change in a wide range of taxa.
Predator–prey dynamics and the plasticity of predator body size
Authors: DeLong John P. , Hanley Torrance C. , Vasseur David A. 
Published: October 2013

Summary

Body size is of fundamental importance to the structure and function of natural systems, yet the factors selecting for certain body sizes are still not well understood. Resource supply levels clearly play a role in setting size, but in current theory, optimality functions for body size are not tied to the population dynamics that govern resource supply, minimizing our ability to understand how body size evolves in response to the ecological context.

We integrated the supply‐demand (SD) model of body size evolution with a model of predator–prey dynamics to create a dynamic SD model that describes predator body size variation through time. We tested the model with experimental data on body size and abundance dynamics in the Didinium–Paramecium predator–prey system. We used a new differential equation fitting approach along with independently estimated parameters to determine whether the model could simultaneously capture both abundance and body size dynamics.

The dynamics were well described by the model, supporting the notion that body size changes to match bodily demand for resources with the available supply of resources. Surprisingly, despite the 10‐fold variation in Didinium body size, we found that static model parameters were sufficient to describe the data, suggesting a lack of eco‐evolutionary dynamics.

A pressing need in ecology is to be able to predict changes in body size under novel scenarios, especially climate warming. The dynamic SD model does this by linking body size to the ecological context in an eco‐evolutionary framework. Our approach expands our ability to understand rapid linked changes in traits and abundance.
An allelopathic plant facilitates species richness in the Mediterranean garrigue
Authors: Ehlers Bodil K. , Charpentier Anne , Grøndahl Eva 
Published: October 2013

Summary

Positive plant–plant interactions are known to increase species richness in stressful and poor habitats that are often species poor, but the role of facilitative interactions in species‐rich communities is less well understood. It has been proposed that allelopathic plants may create non‐transitive species interactions, which increase species coexistence, and that such indirect facilitation may be important in species‐rich communities.

We examined species richness in 12 different plant communities all dominated by the aromatic Thymus vulgaris that produces monoterpenes known to inhibit germination and growth of other plants.

We found consistently, and across communities, higher species richness in microsites with thyme than without. Species richness in microsites with, respectively without, two other perennial plants did not differ, suggesting that increased species richness in thyme microsites is due to the presence of thyme. We found a more similar species composition among thyme microsites and positive estimates of thyme on landscape richness enhancement, indicating that thyme also affect richness at the community level. However, across communities, we did not find species consistently confined to thyme microsites, albeit within communities some plants were exclusive to thyme.

Abundance of a dominant grass was reduced in microsites where thyme produces the monoterpene carvacrol, suggesting that one mechanism by which thyme facilitates species richness was by the repression of a superior competitor that could allow other species to persist. However, this does not explain higher species richness in microsites of thyme producing other monoterpenes. We discuss how chemical variation in thyme and adaptation of associated species to local monoterpenes may affect richness and community diversity.

Synthesis. Allelopathic plants are generally believed to negatively impact upon the performance of associated species. However, allelopathic plants may be important determinants of species richness at the community level by creating microenvironments where species‐specific interactions differ. Our finding shows that thyme increases species richness both locally and at the community level by creating a mosaic of thyme‐modified and unmodified microsites differing in richness and composition. We suggest that this may also apply to other aromatic plants common in Mediterranean vegetation.
Influences of social network sites on the occupational performance of adolescents in a secondary school in Cape Town, South Africa: A phenomenological study
Authors: Mthembu Thuli G. , Beets Charmaine , Davids Gafeedha , Malyon Kelly , Pekeur Marchelle , Rabinowitz Avital 
Published: October 2013

Background/aimThe habit of using social networking sites among adolescents has grown exponentially; there is little accompanying research to understand the influences on adolescents' occupational performance with this technology. The majority of adolescents are engaging in social network as part of their daily routines. Occupational performance is the act of doing and accomplishing a selected occupation that results from the dynamic transaction among the person, the environment and the occupation components. This study aimed to explore the influences of social networking on occupational performance of adolescents in a high school in Western Cape Province, South Africa.MethodsA phenomenological approach was used. Adolescents aged 13–17 years in a high school were purposively recruited for the study. Semi‐structured interviews were conducted with four participants (two adolescents and two teachers) and two focus groups were undertaken with adolescents, analysed using thematic analysis.ResultsFour major themes emerged: ‘It's a good way to keep in touch’, ‘It's part of me and it's not a bad thing’, ‘There is a time and place for it’ and ‘There's an urgency to be on the phone’.ConclusionsThis study highlighted that social networking sites play a major role in the social life of adolescents, though it can result in occupational imbalance on their occupational performance. Furthermore, this study contributes to the knowledge of occupational therapists who work with adolescents in communities and health promoting school settings. Thus, collaboration between teachers, parents and occupational therapists can help to develop adolescents’ time management and learning skills.