bluuebunny/crossref_metadata_2025_split huggingface dataset:
Colony specific morphological caste differences in an Old World, swarm‐founding polistine,Ropalidia romandi(Hymenoptera: Vespidae)
Authors: Fukuda Hirokazu , Kojima Jun‐ichi , Jeanne Robert L. 
Published: December 2004

AbstractMorphological differences between queens and workers in an Australian swarm‐founding paper wasp,Ropalidia romandi, were examined, providing detailed information on the nature of morphological caste differences in swarm‐foundingRopalidiafor the first time. Queens and workers differed in overall size and had divergent shapes, but differences were not always significant. In colonies in which queen–worker dimorphism was distinct, while the head width of queens was nearly the same as that of workers, queens were significantly larger in measures on the metasoma than workers. Plotting of metasomal variables against the mesosomal length and analysis of covariance showed that queen–worker morphological differentiation inR. romandicannot be explained by simple linear allometric growth, suggesting that the two castes diverge in their growth parameters in the preadult stage. The pattern of morphological caste difference varied among colonies or was colony specific; there was no clear correlation between caste differences and colony cycle progression. These results suggest that morphological caste differences inR. romandiare determined genetically or by interactions between genetic background and intrinsic factors and/or external conditions.
Estimation of the thermal separation of soil particles from the thermal conductivity under reduced air pressure
Authors: Momose T. , Kasubuchi T. 
Published: December 2004

SummaryKnowledge of thermal conductivity of granular materials under reduced air pressure can be utilized for studying intricate mechanisms of heat transfer in two‐phase systems. We measured the thermal conductivity of three soils of varied texture and two sets of glass beads (GB) under reduced air pressure using a twin heat probe. We also predicted the thermal conductivity of a two‐phase system at reduced air pressure from the modified Woodside & Messmer equation based on the kinetic theory of gases. This equation includes a thermal separation of solid particles (d) defined by the heat conduction. We compared this separation with the geometrical mean separation of solid particles (D). The results showed a linear relation between d and D for the GB, and in all cases d was smaller than D. This suggests that conductive heat transfer in two‐phase GB takes place mainly through air spaces the dimension of which is smaller than D.The d of a Red Yellow soil and an Ando soil, however, were about 200–300 times larger than D. This result seems to be related to the soil aggregation. We showed that in soil aggregates the conduction of heat through the solid was the dominant mode of heat transfer, and the micropores in a soil aggregate had very little effect on the diminished thermal conductivity under reduced air pressure. The decrease in the thermal conductivity of two‐phase soil under reduced air pressure is probably caused by the air molecules confined in interaggregate pore spaces rather than those in the intra‐aggregate pore spaces. The d of soils can be used to represent the thermal separation of the interaggregate pore spaces, and soil aggregates can be treated as single‐grained particles in evaluating heat conduction.
Frequencies of TAP1 and TAP2 gene polymorphisms in the Anatolian population
Authors: Özbaş‐Gerçeker F. , Özgüç M. 
Published: December 2004

SummaryAnatolia has a long and complex record of immigration from various regions. Here, we have used TAP1 and TAP2 gene polymorphisms as genetic markers to study the relationship between the Anatolian population and other populations. A neighbour‐joining tree was constructed indicating the relatedness of European populations and the Anatolian population with respect to TAP1 and TAP2 allele frequencies.
Immunogenetics of the rare HLA‐B allele B*4408†
Authors: Street J. , Downing J. , Darke C. 
Published: December 2004

SummaryThe nucleotide sequence of exons 2 and 3 of B*4408 has been confirmed. This allele has now been found in five, apparently unrelated, north‐western European Caucasoid subjects, residing in Wales, on HLA haplotypes bearing: A*0201, Cw*0501 with DRB1*0401, DQA1*03, DQB1*0301 in four instances and DRB1*0701, DQA1*0201, DQB1*0202 in one instance. The unique serological reactivity of ‘HLA‐B44BO’ was established using up to nine B*4408 subjects and was easily identified using a variety of B44 and B62 antisera. The phenotype and gene frequencies of B*4408, in a sample of 40 473 subjects residing in Wales, were 0.01235% and 0.00006, respectively.
Serological identification of a non‐HLA antigen in Oriental populations
Authors: Yang K. L. , Schroeder M. L. , Cherng J. M. , Lin P. Y. 
Published: December 2004

SummaryIn a routine HLA antibody screening cross‐match test using the complement‐mediated lymphocytotoxicity (LCT) assay, we discovered an antibody, in a transfused Caucasian woman, recognizing an Oriental restricted antigen that does not appear to be associated with the human leukocyte antigen (HLA) system. The distribution of this ‘novel’ antigen in Oriental populations and its frequency in the Taiwanese Chinese population are reported.
Ionic concentrations in a blanket peat bog in northern England and correlations with deposition and climate variables
Authors: Adamson J. K. , Scott W. A. , Rowland A. P. , Beard G. R. 
Published: December 2004

SummarySoil solution was collected to identify seasonal trends in its chemistry and to examine relationships between the concentrations of ions and variables that may control them. Samples were collected fortnightly at 10 cm and 50 cm depth in a blanket peat soil at Moor House–Upper Teesdale National Nature Reserve in the northern Pennine uplands of England. Dissolved organic carbon at 10 cm peaked each summer and correlated most strongly with temperature. At both depths Na+ and Cl– were the dominant ions, reflecting the oceanic climate. Over the 3‐year sampling period, concentrations of the principal anions and cations at 10 cm varied little except during the autumns of 1994 and 1995 following unusually dry summers. At these times concentrations of SO42–‐S increased from < 3 μmol to a maximum of 430 μmol and were balanced by smaller increases in Na+, Mg2+, Ca2+ and H+. The SO42– concentration at 10 cm was most strongly correlated with depth to the water Table 3 weeks prior to sampling. At 50 cm depth in the peat a small increase in SO42– occurred only during the autumn of 1995, and the concentration of SO42– at this depth correlated most strongly with that at 10 cm. At neither depth were there any strong correlations with deposition. The increase in H+ concentration associated with the peak in SO42– at 10 cm depth represents a fall in pH from usual values around 4.2 to 3.5.

Deposition flux of ions in bulk precipitation at Moor House from weekly samplings 1994 to 1996 in kg ha−1 year−1. The UK flux is derived from 32 sites of the United Kingdom Precipitation Composition Monitoring Network 1992 to 1994 and the standard deviation (SD) relates to the variation between these sites (Review Group on Acid Rain, 1997)

Moor House flux
UK flux
UK SD

H+
0.31
0.26
0.10

Ca2+
4.07
3.58
1.86

Mg2+
3.37
3.62
2.62

K+
1.54

Fe2+
0.73

Al3+
0.44

Na+
29.32
25.77
19.27

Cl–
51.14
45.96
32.39

NO3–‐N
4.01
3.20
1.05

NH4+‐N
4.85
3.63
1.74

SO42–‐S
8.98
7.98
3.09

PO43–‐P
0.01
A 13C tracer study to identify the origin of dissolved organic carbon in forested mineral soils
Authors: Hagedorn F. , Saurer M. , Blaser P. 
Published: December 2004

SummaryThe relative contributions of sources of carbon in soils, such as throughfall, litter, roots, microbial decay products and stable organic fractions, to dissolved organic C are controversial. To identify the origin of dissolved organic C, we made use of a 4‐year experiment where spruce and beech, growing on an acidic loam and on a calcareous sand, were exposed to increased CO2 that was depleted in 13C. We traced the new C inputs from trees into dissolved organic C, into water‐extractable organic C, and into several particle‐size fractions. In addition, we incubated the labelled soils for 1 year and measured the production of dissolved organic C and CO2 from new and old soil C. In the soil solutions of the topsoil, the dissolved organic C contained only 5–10% new C from the trees. The δ13C values of dissolved organic C resembled those of C pools smaller than 50 µm, which strongly suggests that the major source of dissolved organic C was humified old C. Apparently, throughfall, fresh litter and roots made only minor contributions to dissolved organic C. Water‐extractable organic C contained significantly larger fractions of new C than did the natural dissolved organic C (25–30%). The δ13C values of the water‐extractable organic C were closely correlated with those of sand fractions, which consisted of little decomposed organic carbon. The different origin of dissolved and water‐extractable organic C was also reflected in a significantly larger molar UV absorptivity and a smaller natural 13C abundance of dissolved organic C. This implies that the sampling method strongly influences the characteristics and sources of dissolved organic C. Incubation of soils showed that new soil C was preferentially respired as CO2 and only a small fraction of new C was leached as dissolved organic C. Our results suggest that dissolved organic C is produced during incomplete decomposition of recalcitrant native C in the soils, whereas easily degradable new components are rapidly consumed by microbes and thus make only a minor contribution to the dissolved C fraction.
Sorption of primisulfuron on soil, and inorganic and organic soil colloids
Authors: Pusino A. , Petretto S. , Gessa C. 
Published: December 2004

SummaryInorganic and organic soil colloids are responsible for the sorption of many pesticides. We studied the sorption of the herbicide primisulfuron [methyl 2 N‐[[[[[4,6‐bis(difluoromethoxy)‐2‐pyrimidinyl]amino]carbonyl]amino]sulfonyl]benzoate] on Fe3+‐, Al3+‐, Ca2+‐ and Na+‐exchanged montmorillonite, soil organic matter (H+‐ and Ca2+‐saturated), amorphous iron oxide, and three soils in aqueous media. The sorption on soils was negatively correlated with pH. Ca2+‐ and Na+‐exchanged montmorillonites are ineffective in the sorption of primisulfuron. The sorption on Fe3+‐ and Al3+‐exchanged montmorillonite is rapid and follows the Freundlich equation. Fourier transform infrared (FT‐IR) and X‐ray powder diffraction studies of the Fe3+‐ and Al3+‐montmorillonite samples after the interaction with primisulfuron in chloroform solution suggest that primisulfuron is adsorbed and degraded in the interlayer. Humic acid is more effective in the sorption than is Ca humate, suggesting that the pH of the suspension (3.5 for humic acid and 6.0 for Ca humate) has a strong influence on the sorption of primisulfuron. Experiments on amorphous iron oxide indicate similar pH dependence. Infrared spectra indicate that the protonation of the pyrimidine nitrogen moiety of herbicide and subsequent hydrogen bonding with the surface hydroxyls of Fe oxide is the mechanism acting in the primisulfuron sorption.
Collaboration in scientific research: a critical need for freshwater ecology
Authors: Cullen Peter W. , Norris Richard H. , Resh Vincent H. , Reynoldson Trefor B. , Rosenberg David M. , Barbour Michael T. 
Published: December 2004

1. Collaboration means actively working together to achieve things which could not be done alone. This article attempts to provide an overall, unified, guiding framework for collaboration in freshwater ecology by discussing aspects of collaboration at individual and organizational levels, and addressing international linkages.2. The essential elements of collaboration are communication and trust, and effective project management. Barriers to effective collaboration include competition, organizational cultures and organizational instabilities.3. The success of collaboration can be measured by tangible benefits such as increased numbers of peer‐reviewed publications, the production of working models and a number of intangible benefits.4. Interactions between individuals lie at the heart of an effective collaboration; organizational arrangements should facilitate this interaction. Some governments are encouraging collaboration to increase cost efficiency and allocate accountability. This trend should continue on an international level.5. Collaboration is a key to future research in freshwater ecology.
The responses to shade of seedlings of very small‐seeded tree and shrub species from tropical rain forest in Singapore
Authors: METCALFE D. J. , GRUBB P. J. 
Published: December 2004

1. Newly germinated seedlings of six tree and shrub species with very small seeds (31–460 μg dry mass), one light‐demanding and five shade‐tolerant at the stage of establishment in the wild, were grown for 5 months in neutral shade houses with 0·5, 1, 3·5 and 7·5% daylight. 2. The ratio of yield in 7·5% to that in 1% was 8:1 for the light‐demanding Melastoma malabathricum but only 2:1 for the confamilial shade‐tolerator Pternandra echinata. The Pternandra, Urophyllum hirsutum, Ficus chartacea, Ficus grossularioides and Pellacalyx saccardianus showed a graded series of responses to irradiance, generally consistent with their apparent demands for light in the wild. In contrast, survival of very deep shade was not clearly related to light demand in nature. 3. The results support the conclusion drawn from observational studies that large seed size is not primarily adaptive in resisting shade but in resisting the associated risks of burial by litter, desiccation during dry spells, uprooting by birds and other kinds of damage by animals or falling debris.
Association between haematozoan infections and reproduction in the Pied Flycatcher
Authors: SIIKAMÄKI P. , RÄTTI O. , HOVI M. , BENNETT G. F. 
Published: December 2004

1. Parasites may affect breeding success of their host since they compete for the same resources as their hosts. Reproduction may also increase the susceptibility of a host to parasite infections owing to lowered resistance to parasites during breeding. 2. We studied the association between breeding performance and haematozoan parasite infection in the Pied Flycatcher (Ficedula hypoleuca) by using both natural data on reproduction and data from clutch size manipulations. 3. The most frequent blood parasites of the Pied Flycatcher in central Finland were Haemoproteus pallidus, Haemoproteus balmorali and Trypanosoma avium complex. 4. We did not find evidence that these haematozoan parasites have any debilitating effects on either reproduction or survival. The variation in reproductive effort did not seem to influence susceptibility to new blood parasite infections. 5. The intensity of Haemoproteus balmorali tended to increase in infected males as the brood size was artificially enlarged. Also, in females intensity of H. pallidus infection tended to increase with the level of clutch size manipulation. Thus, increased reproductive effort seems to debilitate the ability of Pied Flycatcher to control chronic infections. 6. Individuals with enlarged clutches/broods increased their reproductive effort at the expense of defence towards parasites. The cost of current reproduction may then be at least partly mediated by haematozoan infections.
Molecular genetic elucidation of the tripartite structure of the Schizosaccharomyces pombe 72 kDa TFIID subunit which contains a WD40 structural motif
Authors: Yamamoto Tohru , Poon David , Anthony Weil P. , Horikoshi Masami 
Published: December 2004

Background: The multisubunit general transcription factor termed TFIID is comprised of the TATA box DNA binding protein TBP and several TBP‐associated factors termed TAFs. Current arguments regarding the mechanisms of regulation of transcription contend that TFIID makes multiple specific protein–protein interactions with numerous protein factors, and that these interactions are important for the regulation of transcriptional initiation. TAFs contain a variety of potential structural motifs and it has been speculated that these motifs participate directly in TAF function. However, to date the physiological significance of these putative structural motifs has not been systematically analysed in vivo. Results: The essential gene encoding the Schizosaccharomyces pombe 72 kDa TFIID subunit is termed taf72+, which contains WD40 repeats, was cloned and sequenced. A comparison of the primary structure of this gene with its Drosophila and S. cerevisiae counterparts suggests the presence of regions that might play a role in TFIID function, due to the fact that significant portions of the sequences are highly conserved. Complementation analyses of a series of deletion mutants of this gene revealed that the most evolutionarily conserved regions of taf72+, including the WD40 repeats, are in fact indispensable for the viability. Conclusions: The 72 kDa subunit of S. pombe TFIID, which contains putative WD40 repeats, consists of three distinct functional domains separated by intervening regions. The functional significance of the WD40 repeats is demonstrated by this in vivo study.
Simulating vegetation processes along the Kalahari transect
Authors: Woodward F. I. , Lomas M. R. 
Published: December 2004

AbstractThe Sheffield Dynamic Global Vegetation Model has simulated the structure and net carbon exchange of vegetation at five sites along the Kalahari transect where there is a strong gradient in precipitation from 299 to 918 mm yr−1. There has been a decline in precipitation of 8 mm yr−1 along the whole of the transect since about 1970. Simulations of vegetation dynamics and structure indicate that this decline has exerted a notable effect on the vegetation, with reductions in woody plant cover at the dry end of the transect and reductions in tree density at the wetter end. These changes were driven primarily by reductions in the net primary production and increased rates of mortality, with rather small impacts of fire.
Canopy scale measurements of CO2 and water vapor exchange along a precipitation gradient in southern Africa
Authors: Scanlon Todd M. , Albertson John D. 
Published: December 2004

AbstractShort‐term measurements of carbon dioxide, water, and energy fluxes were collected at four locations along a mean annual precipitation gradient in southern Africa during the wet (growing) season with the purpose of determining how the observed vegetation–atmosphere exchange properties are functionally related to the long‐term climatic conditions. This research was conducted along the Kalahari Transect (KT), one in the global set of International Geosphere‐Biosphere Program transects, which covers a north–south aridity gradient, all on a homogenous sand formation. Eddy covariance instruments were deployed on a permanent tower in Mongu, Zambia (879 mm of rainfall per year), as well as on a portable tower in Maun (460 mm yr−1), Okwa River Crossing (407 mm yr−1), and Tshane (365 mm yr−1), Botswana for several days at each site. The relationships between CO2 flux, Fc, and photosynthetically active radiation were described well by a hyperbolic fit to the data at all locations except for Mongu, the wettest site. Here, there appeared to be an air temperature effect on Fc. While daytime values of Fc routinely approached or exceeded −20 μmol m−2 s−1 at Mongu, the magnitude of Fc remained less than −10 μmol m−2 s−1 when the air temperature was above 27°C. Canopy resistances to water vapor transfer, rc, displayed an overall decline from the wetter sites to the more arid sites, but the differences in rc could be almost exclusively accounted for by the decrease in leaf area index (LAI) from north to south along the KT. Ecosystem water use efficiency (WUE), defined as the ratio of net carbon flux to evapotranspiration, showed a general decrease with increasing vapor pressure deficit, D, for all of the sites. The magnitudes of WUE at a given D, however, were dissimilar for the individual sites and were found to be stratified according to the position of the sites along the long‐term aridity gradient. For example, Mongu, which has the wettest climate, has a much lower WUE for like levels of D than Tshane, which historically has the most arid climate. Given the similar inferred stomatal resistances between the sites, the disparate carbon uptake behavior for the grass vs. woody vegetation is the likely cause for the observed differences in WUE along the aridity gradient. The short‐term flux measurements provide a framework for evaluating the vegetation's functional adaptation to the long‐term climate and provide information that may be useful for predicting the dynamic response of the vegetation to future climate change.
Canopy structure in savannas along a moisture gradient on Kalahari sands
Authors: Scholes Robert J. , Frost Peter G. H. , Tian Yuhong 
Published: December 2004

AbstractMeasurements of tree canopy architecture were made at six savanna sites on deep, sandy soils, along a gradient of increasing aridity. There was substantial variation in the leaf area estimated within each site, using the same sample frame, but different measurement techniques. The trends in canopy properties in relation to the aridity gradient were consistent, regardless of the technique used for estimating the properties. The effective plant area index for the tree canopy (the sum of the stem area index and the leaf area index (LAI)) declined from around 2 to around 0.8 m2 m−2 over a gradient of mean annual rainfall from 1000 to 350 mm. Stems contributed 2–5% of the tree canopy plant area index. Since the tree canopy cover decreased from 50% to 20% over this aridity range, the leaf area index within the area covered by tree canopies remained fairly constant at 3–4 m2 m−2. Tree leaves tended from a horizontal orientation to a more random orientation as the aridity increased. On the same gradient, the leaf minor axis dimension decreased from around 30 mm to around 3 mm, and the mean specific leaf area decreased from 14 to 5 m2 kgha−1. There was good agreement between LAI observed in the field using a line ceptometer and the LAI inferred by the MODIS sensor on the Terra satellite platform, 2 months later in the same season.