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51.
The decomposition of soil organic carbon (SOC) plays a critical role in regulating atmospheric CO2 concentrations and climate dynamics. However, the mechanisms and factors controlling SOC decomposition are still not
fully understood. Here, we conducted a 60 days incubation experiment to test the effects of physical disturbance
and nitrogen (N) addition on SOC decomposition. N addition increased the concentration of NO3- by 51% in the
soil, but had little effect on the concentration of NH4+. N addition inhibited SOC decomposition, but such an
effect differed between disturbed and undisturbed soils. In disturbed and undisturbed soils, application of N
decreased SOC decomposition by 37% and 15%, respectively. One possible explanation is that extra N input suppressed microbial N mining and/or increased the stability of soil organic matter by promoting the formation of
soil aggregates and incorporating part of the inorganic N into organic matter, and consequently decreased microbial mineralization of soil organic matter. Physical disturbance intensified the inhibition of N on SOC decomposition, likely because physical disturbance allowed the added N to be better exposed to soil microbes and
consequently increased the availability of added N. We conclude that physical disturbance and N play important
roles in modulating the stability of SOC. 相似文献
52.
Background
The analysis of microarray experiments requires accurate and up-to-date functional annotation of the microarray reporters to optimize the interpretation of the biological processes involved. Pathway visualization tools are used to connect gene expression data with existing biological pathways by using specific database identifiers that link reporters with elements in the pathways. 相似文献53.
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55.
Wenqiang Chen Salomon Kuizon Bair L. Chiou David C. Bolton Raju K. Pullarkat Mohammed A. Junaid 《Neurochemical research》2009,34(9):1658-1667
Ataxia telangiectasia (A-T) is a progressive neurodegenerative disorder caused by disruption of the gene, ataxia telangiectasia
mutated (ATM). Present study was aimed at identifying proteins that are present in abnormal levels in A-T brain that may identify alternative
targets for therapeutic interventions. Proteomic and Western blot analysis have shown massive expression of the small heat
shock protein 27 (Hsp27) in frontal cortices of A-T brains compared to negligible levels in controls. The expression of other
stress proteins, Hsp70, αB-crystallin, and prohibitin remained unchanged in the A-T and control brains. Significant decreases
in reactive oxygen species, protein carbonyl groups and lipid peroxidation products were observed in the A-T brains. There
is no evidence of caspase 3 activation or DAXX mediated apoptosis. We propose that neurons in the frontal lobe are protected
by the expression of Hsp27, which scavenges the oxidative stress molecules formed consequent to the primary loss of ATM function. 相似文献
56.
57.
Junaid Sarah Gupta Sanjay Sanghavi Sanjay Anglin Carolyn Roger Emery Amis Andrew Hansen Ulrich 《Journal of biomechanics》2010,43(4):714-719
Fixation failure of glenoid components is the main cause of unsuccessful total shoulder arthroplasties. The characteristics of these failures are still not well understood, hence, attempts at improving the implant fixation are somewhat blind and the failure rate remains high. This lack of understanding is largely due to the fundamental problem that direct observations of failure are impossible as the fixation is inherently embedded within the bone.Twenty custom made implants, reflecting various common fixation designs, and a specimen set-up was prepared to enable direct observation of failure when the specimens were exposed to cyclic superior loads during laboratory experiments. Finite element analyses of the laboratory tests were also carried out to explain the observed failure scenarios.All implants, irrespective of the particular fixation design, failed at the implant–cement interface and failure initiated at the inferior part of the component fixation. Finite element analyses indicated that this failure scenario was caused by a weak and brittle implant–cement interface and tensile stresses in the inferior region possibly worsened by a stress raiser effect at the inferior rim.The results of this study indicate that glenoid failure can be delayed or prevented by improving the implant/cement interface strength. Also any design features that reduce the geometrical stress raiser and the inferior tensile stresses in general should delay implant loosening. 相似文献
58.
Irina A. Omelchenko Renu K Jain Mohammed A. Junaid S.L.N. Rao Charles N. Allen 《Neurochemical research》1999,24(6):791-797
Lathyrism is a non-progressive motor neuron disease produced by consumption of the excitatory amino acid, 3-N-oxalyl-L-2,3-diaminopropanoic acid (-ODAP). To learn more about the mechanisms underlying Lathyrism three structural analogs of -ODAP were synthesized. Carboxymethyl-,-diaminopropanoic acid (CMDAP) evoked inward currents which were antagonized by APV (30 M), but not by CNQX (10 M). N-acetyl-,-diaminopropanoic acid (ADAP) evoked no detectable ionic currents but potentiated N-methyl-D-aspartate (NMDA)-activated currents. The potentiation of NMDA currents by ADAP was blocked by 7-chlorokynurenic acid. Carboxymethylcysteine (CMC) did not activate any detectable ionic currents. None of the three -ODAP analogs produced visible symptoms of toxicity in day old chicks when administered for 2–3 consecutive days. Ligand binding studies demonstrated that all the three compounds were effective to in displacing [3H]glutamate. The maximum inhibition was 92% for CMDAP, 61% for ADAP, 65% for CMC and 99% for -ODAP. These data indicate that analogs of -ODAP may interact with glutamate receptors without producing neurotoxicity. 相似文献
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60.
Habib Ul Hassan Qadeer Mohammad Ali Wali Khan Zubia Masood M.F. Aid Abdel-Aziz Muhammad Ishaq Ali Shah Karim Gabol Junaid Wattoo Anser Mahmood Chatta Mustafa Kamal Talha Zulfiqar Md. Yeamin Hossain 《Saudi Journal of Biological Sciences》2021,28(12):7360-7366
A 70-day rearing trial was done to determine the optimal frequency of feeding on growth performance (GP), feed conversion rate (FCR), cannibalism, survival rate (SR), body chemical composition and economic efficiency of the Asian sea bass. This study tested four different treatments of feeding frequencies (FF), once (T1), twice (T2), three times (T3), and four times (T4) per day. An average initial weight of Asian sea bass fry was 0.2 g (SD = ±0.12) were stocked 10 individuals per m3 (9.14 m × 1.82 m × 1.22 m, L × W × H; water depth 0.61 m) with two replicates per treatment (4 × 2 = 8). Fry were fed a mixture of larval commercial feed and shrimp with a pellet diet containing (46% CP). Initially, the feeding rate of 8% biomass per day was further adjusted according to fish biomass on a weekly basis. Results showed that, the FF significantly affected (p < 0.05) on growth indictors and survival rate (SR). Specifically fry fed three times a day (T3) had the best FBW, FL, SGR, ADWG and FCR followed by T4 and T2 while fry fed one time a day was the lowest in these parameters. Also, VSI, HSI and CF (k) significantly differed among the treatments. The fish whole body content of protein, moisture and ash did not significantly (p < 0.05) be affected by feeding frequency, but lipid content differed and both T3, T4 were the highest. It could be concluded that, increasing FF up to three times a day had a positive effect on weight gain, survival rate and feed utilization of Lates calcarifer. The second degree polynomial regression indicates that fed three times a day is optimum for best growth performance and survival for Asian sea bass. 相似文献