bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methane and nitrous oxide fluxes in annual and perennial land‐use systems of the irrigated areas in the Aral Sea Basin
Authors: SCHEER CLEMENS , WASSMANN REINER , KIENZLER KIRSTEN , IBRAGIMOV NAZAR , LAMERS JOHN P.A. , MARTIUS CHRISTOPHER 
Published: May 2008

AbstractLand use and agricultural practices can result in important contributions to the global source strength of atmospheric nitrous oxide (N2O) and methane (CH4). However, knowledge of gas flux from irrigated agriculture is very limited. From April 2005 to October 2006, a study was conducted in the Aral Sea Basin, Uzbekistan, to quantify and compare emissions of N2O and CH4 in various annual and perennial land‐use systems: irrigated cotton, winter wheat and rice crops, a poplar plantation and a natural Tugai (floodplain) forest. In the annual systems, average N2O emissions ranged from 10 to 150 μg N2O‐N m−2 h−1 with highest N2O emissions in the cotton fields, covering a similar range of previous studies from irrigated cropping systems. Emission factors (uncorrected for background emission), used to determine the fertilizer‐induced N2O emission as a percentage of N fertilizer applied, ranged from 0.2% to 2.6%. Seasonal variations in N2O emissions were principally controlled by fertilization and irrigation management. Pulses of N2O emissions occurred after concomitant N‐fertilizer application and irrigation. The unfertilized poplar plantation showed high N2O emissions over the entire study period (30 μg N2O‐N m−2 h−1), whereas only negligible fluxes of N2O (<2 μg N2O‐N m−2 h−1) occurred in the Tugai. Significant CH4 fluxes only were determined from the flooded rice field: Fluxes were low with mean flux rates of 32 mg CH4 m−2 day−1 and a low seasonal total of 35.2 kg CH4 ha−1. The global warming potential (GWP) of the N2O and CH4 fluxes was highest under rice and cotton, with seasonal changes between 500 and 3000 kg CO2 eq. ha−1. The biennial cotton–wheat–rice crop rotation commonly practiced in the region would average a GWP of 2500 kg CO2 eq. ha−1 yr−1. The analyses point out opportunities for reducing the GWP of these irrigated agricultural systems by (i) optimization of fertilization and irrigation practices and (ii) conversion of annual cropping systems into perennial forest plantations, especially on less profitable, marginal lands.
Belowground drought response of European beech: fine root biomass and carbon partitioning in 14 mature stands across a precipitation gradient
Authors: MEIER INA C. , LEUSCHNER CHRISTOPH 
Published: May 2008

AbstractHow tree root systems will respond to increased drought stress, as predicted for parts of Central Europe, is not well understood. According to the optimal partitioning theory, plants should enhance root growth relative to aboveground growth in order to reduce water limitations. We tested this prediction in a transect study with 14 mature forest stands of European beech (Fagus sylvaticaL.) by analysing the response of the fine root system to a large decrease in annual precipitation (970–520 mm yr−1). In 3 years with contrasting precipitation regimes, we investigated leaf area and leaf biomass, fine root biomass and necromass (organic layer and mineral soil to 40 cm) and fine root productivity (ingrowth core approach), and analysed the dependence on precipitation, temperature, soil nutrient availability and stand structure. In contrast to the optimal partitioning theory, fine root biomass decreased by about a third from stands with >950 mm yr−1to those with <550 mm yr−1, while leaf biomass remained constant, resulting in a significant decrease, and not an increase, in the fine root/leaf biomass ratio towards drier sites. Average fine root diameter decreased towards the drier stands, thereby partly compensating for the loss in root biomass and surface area. Bothδ13C‐signature of fine root mass and the ingrowth core data indicated a higher fine root turnover in the drier stands. Principal components analyses (PCA) and regression analyses revealed a positive influence of precipitation on the profile total of fine root biomass in the 14 stands and a negative one of temperature and plant‐available soil phosphorus. We hypothesize that summer droughts lead to increased fine root mortality, thereby reducing root biomass, but they also stimulate compensatory fine root production in the drier stands. We conclude that the optimal partitioning theory fails to explain the observed decrease in the fine root/leaf biomass ratio, but is supported by the data if carbon allocation to roots is considered, which would account for enhanced root turnover in drier environments.
Expansion of gallery forests into central Brazilian savannas
Authors: SILVA LUCAS C. R. , STERNBERG LEONEL , HARIDASAN MUNDAYATAN , HOFFMANN WILLIAM A. , MIRALLES‐WILHELM FERNANDO , FRANCO AUGUSTO C. 
Published: May 2008

AbstractUpland tropical forests have expanded and contracted in response to past climates, but it is not clear whether similar dynamics were exhibited by gallery (riparian) forests within savanna biomes. Because such forests generally have access to ample water, their extent may be buffered against changing climates. We tested the long‐term stability of gallery forest boundaries by characterizing the border between gallery forests and savannas and tracing the presence of gallery forest through isotopic analysis of organic carbon in the soil profile. We measured leaf area index, grass vs. shrub or tree coverage, the organic carbon, phosphorus, nitrogen and calcium concentrations in soils and the carbon isotope ratios of soil organic matter in two transitions spanning gallery forests and savanna in a Cerrado ecosystem. Gallery forests without grasses typically show a greater leaf area index in contrast to savannas, which show dense grass coverage. Soils of gallery forests have significantly greater concentrations of organic carbon, phosphorus, nitrogen and calcium than those of savannas. Soil organic carbon of savannas is significantly more enriched in13C compared with that of gallery forests. This difference in enrichment is in part caused by the presence of C4grasses in savanna ecosystem and its absence in gallery forests. Using the13C abundance as a signature for savanna and gallery forest ecosystems in 1 m soil cores, we show that the borders of gallery forests have expanded into the savanna and that this process initiated at least 3000–4000bpbased on14C analysis. Gallery forests, however, may be still expanding as we found more recent transitions according to14C activity measurements. We discuss the possible mechanisms of gallery forest expansion and the means by which nutrients required for the expansion of gallery forest might accumulate.
The AZF proteins
Authors: Vogt P. H. , Falcao C. L. , Hanstein R. , Zimmer J. 
Published: May 2008

SummaryThe azoospermia factor (AZF) locus in Yq11 is now functionally subdivided in three distinct spermatogenesis loci: AZFa, AZFb and AZFc. After knowledge of the complete genomic Y sequence in Yq11, 14 Y genes encoding putatively functional proteins and expressed in human testis are found to be located in one of the three AZF intervals. Therefore, a major question for each infertility clinic performing molecular screening for AZF deletions has now raised concerning the functional contribution of the encoded AZF proteins to human spermatogenesis. Additionally, it has been shown that distinct chromatin regions in Yq11 overlapping with the genomic AZFb and AZFc intervals are probably involved in the pre‐meiotic X and Y chromosome pairing process. An old hypothesis on the germ line function of AZF becomes therefore revitalized. It proposed a specific chromatin folding code in Yq11, which controls the condensation cycle of the Y chromosome in the male germ line. Thus, with the exception of AZF proteins functionally expressed during the pre‐meiotic differentiation and proliferation of spermatogonia, the need for AZF proteins functionally expressed at meiosis or during the post‐meiotic spermatid maturation process is difficult to assess before the identification of specific mutations in the corresponding AZF gene causing male infertility.
The 20‐minute team – a critical case study from the emergency room
Authors: Berlin Johan M. , Carlström Eric D. 
Published: May 2008

AbstractRationale  In this article, the difference between team and group is tested empirically. The research question posed is How are teams formed? Three theoretical concepts that distinguish groups from teams are presented: sequentiality, parallelism and synchronicity. The presumption is that groups cooperate sequentially and teams synchronously, while parallel cooperation is a transition between group and team.Methods  To answer the question, a longitudinal case study has been made of a trauma team at a university hospital. Data have been collected through interviews and direct observations. Altogether the work of the trauma team has been studied for a period of 5 years (2002–2006).Results  The results indicate that two factors are of central importance for the creation of a team. The first is related to its management and the other to the forms of cooperation. To allow for a team to act rapidly and to reduce friction between different members, clear leadership is required.Conclusions  The studied team developed cooperation with synchronous elements but never attained a level that corresponds to idealized conceptions of teams. This is used as a basis for challenging ideas that teams are harmonious and free from conflicts and that cooperation takes place without friction.
Refined analysis of genetic variability parameters in hepatitis C virus and the ability to predict antiviral treatment response
Authors: Cuevas J. M. , Torres‐Puente M. , Jiménez‐Hernández N. , Bracho M. A. , García‐Robles I. , Carnicer F. , Olmo J. D. , Ortega E. , Moya A. , González‐Candelas F. 
Published: May 2008

Summary.  Hepatitis C virus (HCV) infects approximately 3% of the world population. The chronicity of hepatitis C seems to depend on the level of genetic variability. We have recently (Torres‐Puente et al., J Viral Hepat, 2008; 15: 188) reported genetic variability estimates from a large‐scale sequence analysis of 67 patients infected with HCV subtypes 1a (23 patients) and 1b (44 patients) and related them to response, or lack of, to alpha‐interferon plus ribavirin treatment.. Two HCV genome regions were analysed in samples prior to antiviral therapy, one compressing the three hypervariable regions of the E2 glycoprotein and another one including the interferon sensitive determining region and the V3 domain of the NS5A protein. Haplotype and nucleotide diversity measures showed a clear tendency to higher genetic variability levels in nonresponder than in responder patients. Here, we have refined the analysis of genetic variability (haplotype and nucleotide diversity, number of haplotypes and mutations) by considering their distribution in each of the biologically meaningful subregions mentioned above, as well as in their surrounding and intervening regions. Variability levels are very heterogeneous among the different subregions, being higher for nonresponder patients. Interestingly, significant differences were detected in the biologically relevant regions, but also in the surrounding regions, suggesting that the level of variability of the whole HCV genome, rather than exclusively that from the hypervariable regions, is the main indicator of the treatment response. Finally, the number of haplotypes and mutations seem to be better discriminators than haplotype and nucleotide diversity, especially in the NS5A region.
Genetic diversity enhanced by ancient introgression and secondary contact in East Pacific black mangroves
Authors: NETTEL ALEJANDRO , DODD RICHARD S. , AFZAL‐RAFII ZARA , TOVILLA‐HERNÁNDEZ CRISTIAN 
Published: May 2008

AbstractRegional distribution of genetic diversity in widespread species may be influenced by hybridization with locally restricted, closely related species. Previous studies have shown that Central American East Pacific populations of the wide‐rangedAvicennia germinans, the black mangrove, harbour higher genetic diversity than the rest of its range. Genetic diversity in this region might be enhanced by introgression with the locally restrictedAvicennia bicolor. We tested the hypotheses of ancient hybridization using phylogenetic analysis of the internal transcribed spacer region (ITS) of the nuclear ribosomal DNA and intergenic chloroplast DNA; we also tested for current hybridization by population level analysis of nuclear microsatellites. Our results unveiled ancient ITS introgression between a northern Pacific Central AmericanA. germinanslineage andA. bicolor. However, microsatellite data revealed contemporary isolation between the two species. Polymorphic ITS sequences from Costa Rica and Panama are consistent with a zone of admixture between the introgressant ITSA. germinanslineage and a southern Central American lineage ofA. germinans. Interspecific introgression influenced lineage diversity and divergence at the nuclear ribosomal DNA; intraspecific population differentiation and secondary contact are more likely to have enhanced regional genetic diversity in Pacific Central American populations of the widespreadA. germinans.
Microvasculature of the Medulla Oblongata in the Lyle’s Flying Fox (Pteropus lylei)
Authors: Sricharoenvej S. , Niyomchan A. , Lanlua P. , Piyawinijwong S. , Roongruangchai J. 
Published: May 2008

SummaryThe microvasculature of the medulla oblongata in 15 adult Lyle’s flying foxes (Pteropus lylei) was elucidated by using the vascular corrosion cast technique combined with scanning electron microscopy. The study showed that the medulla received the main arterial supply from branches of the vertebrobasilar system. The supplied areas were divided into three groups: ventral, lateral and dorsal groups. All vessel groups gave off circumferential and perforating branches; moreover, these branches anastomosed with one another in two fashions: end‐to‐end and side‐by‐side arrangements. In addition, the ramifications of the branches were L and Y types. The L type was more frequently found than the Y one. The density of capillaries in the nuclei was greater than that in the area of nerve fibres. Numerous arterial sphincters and smooth muscle cells were observed. Furthermore, capillaries in the medulla were of the continuous type, whereas those in the area postrema were fenestrated. The venous drainage system of the medulla was classified into caudal, middle and rostral parts. All of them emptied into both the sigmoid sinus and internal jugular vein. It was concluded that these vascular patterns provide sufficient blood supply to the medulla oblongata of P. lylei when abrupt changes in the position of this bat occurs.
Effect of Antibiotics in Extender on Bacterial and Spermatozoal Quality of Cooled Buffalo (Bubalus bubalis) Bull Semen
Authors: Akhter S , Ansari MS , Andrabi SMH , Ullah N , Qayyum M 
Published: May 2008

ContentsThe present study was designed to study the effect of traditional antibiotic combination (streptomycin and penicillin; SP) and relatively modern combination of antibiotics (gentamycin, tylosin, lincomycin and spectinomycin; GTLS) in extender on bacterial control and spermatozoal quality of liquid buffalo bull semen stored at 5°C. Semen collected from Nili‐Ravi buffalo bulls (n = 10) was diluted with skim milk extender containing either SP (streptomycin 1000 μg/ml and penicillin 1000 IU/ml), GTLS (gentamycin 500 μg/ml, tylosin 100 μg/ml, lincomycin 300 μg/ml and spectinomycin 600 μg/ml) or negative control with no antibiotics (NA). Liquid semen was stored at 5°C for 5 days. Aerobic bacteria isolated from buffalo semen were Pseudomonas aeruginosa and Staphylococcus aureus. The only facultative anaerobic bacterium isolated was Klebsiella pneumoniae. In vitro antibiotic sensitivity test revealed that Ps. aeruginosa and Staph. aureus were susceptible to gentamycin. Staphylococcus aureus and K. pneumoniae were susceptible to tylosin and linco‐spectinomycin. Total aerobic bacterial count was significantly lower in semen samples treated with GTLS than those of SP on third and fifth day of storage at 5°C. There was no difference (p > 0.05) in sperm motility, longevity and plasma membrane integrity (PMI) in extender containing SP or GTLS combination until the third day of storage at 5°C. On fifth day of storage sperm motility, longevity and PMI was significantly better in extender containing SP compared with GTLS and NA. Intact acrosomes, and sperm head, mid piece and tail abnormalities remained similar (p > 0.05) because of antibiotics up to 5 days of storage. In conclusion, GTLS is more capable than SP for bacterial control of buffalo bull semen. Moreover, GTLS and SP are equally efficient in preserving spermatozoal quality of extended buffalo bull semen for 3 days at 5°C.
Development In Vitro and Mitochondrial Fate of Interspecies Cloned Embryos
Authors: Ma L‐B , Yang L , Hua S , Cao J‐W , Li J‐X , Zhang Y 
Published: May 2008

ContentsAlthough the technique of interspecies somatic cell nuclear transfer can be used to increase the population size of endangered mammals, the mitochondrial heteroplasmy in cloned embryos and animals makes this idea doubtful. In present study, goat–sheep cloned embryos were constructed by fusing goat foetal fibroblasts (GFFs) into sheep oocytes and then cultured in vitro to investigate the capability of sheep oocyte dedifferentiating GFF nucleus. Moreover, at each stage of 1‐ (immediately after fused), 2‐, 4‐, 8‐, 16‐cell, morula and blastocyst, the copy number of mtDNA from GFF and sheep oocyte was examined using real‐time PCR. The results showed that: 7.4% of the fused cloned embryos can develop to the blastocyst stage; in the process of one cell to the morula stage, the copy number of two kinds of mtDNA was stable relatively; however, in the process of morula to the blastocyst stage, the decreasing in the copy number of GFF‐derived mtDNA, while the increasing in sheep oocyte‐derived, resulted in their ratio of decreasing sharply from 2.0 ± 1.0% to 0.012 ± 0.004%. This study demonstrates that: (i) the goat–sheep cloned embryos have the ability to develop to blastocyst in vitro; (ii) from the morula stage to the blastocyst stage of goat–sheep cloned embryos, goat derived mitochondria can be gradually replaced with those from sheep oocyte.
Effect of Chemical or Electrical Activation of Bovine Oocytes on Blastocyst Development and Quality
Authors: Milazzotto MP , Feitosa WB , Coutinho ARS , Goissis MD , Oliveira VP , Assumpção MEOA , Visintin JA 
Published: May 2008

ContentsActivation of in vitro‐matured (IVM) oocytes is essential for successful embryo production following nuclear transfer (NT) or intracytoplasmic sperm injection (ICSI). This study was designed to compare the rates of blastocyst production and embryo quality (as measured by numbers of viable cells) following parthenogenetic activation with electrical pulse or the use of two different calcium ionophores, A23187 (CA) or ionomycin (IO), with or without the addition of bovine serum albumin (BSA). IVM oocytes with a first polar body were randomly allocated to five treatment groups: CA (5 μm CA, 5 min; n = 88), CA + BSA (5 μm CA, 5 min; BSA, 5 min; n = 90), IO (5 μm IO, 5 min; n = 91), IO + BSA (5 μm IO, 5 min; BSA, 5 min; n = 86) and EL (two pulses of 1.5 kV/cm, 20 μs; n = 120). Blastocyst rates were higher (p < 0.05) for CA (54.4%), IO (51.4%) and EL (54.5%) than for IO + BSA (18.3%). Treatment CA + BSA (39.8%) did not differ from the others. There was no difference (p > 0.05) among treatments in total number of cells. However, the percentage of viable cells was reduced in CA (49.9%), CA + BSA (45.8%), IO (64.9%), IO + BSA (50.9%) compared with EL (82.7%). In summary, the addition of BSA to the IO treatment had an adverse effect on blastocyst production rates. Although there was no difference between electrical stimulation and chemical activation on blastocyst production rates, electrical activation resulted in blastocysts with a higher percentage of viable cells.
Use of Fetuin Before and During Vitrification of Bovine Oocytes
Authors: Horvath G , Seidel GE 
Published: May 2008

ContentsAfter vitrification of oocytes, fertilization rates and subsequent development are unsatisfactory, possibly due in part to zona hardening. Foetal calf serum (FCS) can prevent zona hardening because of its fetuin content, but FCS composition varies among batches, and may contain viruses. In this study, we therefore compared media supplemented with different sources of macromolecules, 2% bovine serum albumin (BSA), 2% BSA + 1 mg/ml fetuin and 20% FCS, for handling oocytes for 10–30 min prior to vitrification. None of the treatments resulted in developmental rates comparable with the non‐vitrified controls, but FCS inclusion in pre‐vitrification handling medium resulted in higher blastocyst production per oocyte (p < 0.05) (10.8%) on day 9 of culture than BSA (5.3%) or BSA + fetuin (6.4%). Blastocysts developing from oocytes from all vitrification treatments were somewhat retarded relative to those developed from non‐vitrified oocytes. We also tested the use of fetuin during vitrification as well as two different exposure times with cryoprotectants, 180 and 30 s. There was no significant effect of fetuin or exposure time on rates of subsequent blastocyst production.
Case of Pregnancy in Two Cows with Unicorn Horn of the Uterus either by Artificial Insemination at Ipsilateral or Embryo Transfer at Contralateral Corpus Luteum in the Ovary
Authors: Moriyama C , Kobayashi I , Tani M , Oishi T , Kajisa M , Horii Y , Kamimura S 
Published: May 2008

ContentsTwo Holstein heifers and a cow were diagnosed with White Heifer Disease by ultrasonography. Case 1 was a 14 month‐old heifer with aplasia of both sides of the uterine horn. In case 2, a primiparous cow and case 3, an 18 month‐old heifer, both showed aplasia of the right uterine horn. Case 2 became pregnant by artificial insemination at ipsilateral ovulatory follicle and corpus luteum in the left ovary, while case 3 became pregnant by embryo transfer at 7 days after oestrus with contralateral corpus luteum in the right ovary.
Pregnancy after renal transplantation: A single‐center experience
Authors: Abe Toyofumi , Ichimaru Naotsugu , Okumi Masayoshi , Imamura Ryoichi , Isaka Yoshitaka , Takahara Shiro , Kokado Yukito , Okuyama Akihiko 
Published: May 2008

Objectives:  To examine women with renal transplants who became pregnant, and delivered at our hospital.Methods:  Twenty‐six women who had undergone renal transplantation between 1977 and 2002 became pregnant, and delivered at Osaka University Hospital. Complete medical records of twenty of them were retrieved and retrospectively analyzed.Results:  Overall, twenty‐nine pregnancies occurred in these twenty women after renal transplantation. There were spontaneous abortions in three cases, whereas pregnancy was artificially terminated five times. Thus, neonates were delivered in 21 of 29 pregnancies. One woman delivered twice and two women delivered twins. As a result, a total of 23 neonates were delivered. Mean gestational period was 35.4 weeks (range, 27–41 weeks), and mean birth weight was 2229 g (range, 724–3544 g). Regarding fetal complications, intrauterine growth retardation was observed in three cases. One child with intrauterine growth retardation died at 3 months old due to respiratory distress syndrome. One child displayed double‐outlet right ventricle and another child had congenital unilateral hydronephrosis. Regarding maternal complications, prevalence of toxemia of pregnancy was 38.1%. In four of the 21 deliveries (19.0%), renal function exacerbated after delivery. Rates of graft survival for the 20 women at 1, 5 and 10 years after delivery were 100%, 85.1% and 74.4%, respectively. Prognosis for renal transplant resulted to be significantly poorer for recipients with hypertension before pregnancy than for recipients without hypertension before pregnancy (log‐rank test, P = 0.043).Conclusions:  Rates of graft survival after delivery were mostly favorable. However, prognosis for renal function was poorer for recipients who displayed hypertension prior to pregnancy.