1,217 research outputs found
Photosynthesis in nonâfoliar tissues: implications for yield
Photosynthesis is currently a focus for crop improvement, however the majority of this work has taken place and been assessed in leaves, whilst limited consideration has been given to the contribution that other green tissues make to whole plant carbon assimilation. The major focus of this review is to evaluate the impact of nonâfoliar photosynthesis on carbon use efficiency and total assimilation. Here we appraise and summarise past and current literature on the substantial contribution of different photosynthetically active organs and tissues to productivity in a variety of different plant types, with an emphasis on fruit and cereal crops. Previous studies provide evidence that nonâleaf photosynthesis could be an unexploited potential target for crop improvement. We also briefly examine the role of stomata in nonâfoliar tissues and their role in gas exchange, maintenance of optimal temperatures and thus photosynthesis. In the final section, we discuss possible opportunities to manipulate these processes and provide evidence that wheat plants genetically manipulated to increase leaf photosynthesis, also displayed higher rates of ear assimilation, which translated to increased grain yield. By understanding these processes, we can start to provide insights into manipulating nonâfoliar photosynthesis and stomatal behaviour to identify novel targets for exploitation for onâgoing breeding programmes
Abnormal systolic blood pressure response during exercise is related to subendocardial hypoperfusion detected by exercise 201Tl myocardial scintigraphy in patient with hypertrophic cardiomyopathy
Balcells, EugĂšniaPla general, d'alguns dels elements que formen la taula periĂČdica. Cadascun dels 112 elements Ă©s representat pel seu espectre de color. Es van produir diverses cĂČpies de l'obra, aquesta estĂ a la Biblioteca de la Facultat de QuĂmica
Recovery of Electron/Proton Radiation-Induced Defects in n+p AlInGaP Solar Cell by Minority-Carrier Injection Annealing
A high efficient In0.48Ga0.52P/In0.01Ga0.99As/Ge triple junction solar cell has been developed for application in space and terrestrial concentrator PV system [1-3]. Recently, a high conversion efficiency of 31.5% (AM1.5G) has been obtained in InGaP/(In)GaAs/Ge triple junction solar cell, and as a new top cell material of triple junction cells, (Al)InGaP [1] has been proposed to improve the open-circuit voltage (Voc) because it shows a higher Voc of 1.5V while maintaining the same short-circuit current (ISC) as a conventional InGaP top cell under AM1.5G conditions as seen in figure 1 (a). Moreover, the spectral response of 1.96eV AlInGaP cell with a thickness of 2.5..m shows a higher response in the long wavelength region, compared with that of 1.87eV InGaP cell with 0.6..m thickness, as shown in figure 1 (b). Its development will realize next generation multijunction (MJ) solar cells such as a lattice mismatched AlInGaP/InGaAs/Ge 3-junction and lattice matched AlInGaP/GaAs/InGaAsN/Ge 4-junction solar cells. Figure 2 shows the super high-efficiency MJ solar cell structures and wide band spectral response by MJ solar cells under AM1.5G conditions. For realizing high efficient MJ space solar cells, the higher radiation-resistance under the electron or proton irradiation is required. The irradiation studies for a conventional top cell InGaP have been widely done [4-6], but little irradiation work has been performed on AlInGaP solar cells. Recently, we made the first reports of 1 MeV electron or 30 keV proton irradiation effects on AlInGaP solar cells, and evaluated the defects generated by the irradiation [7,8]. The present study describes the recovery of 1 MeV electron / 30 keV proton irradiation-induced defects in n+p- AlInGaP solar cells by minority-carrier injection enhanced annealing or isochronal annealing. The origins of irradiation-induced defects observed by deep level transient spectroscopy (DLTS) measurements are discussed
Variation in Mitochondrial DNA of Vietnamese Pigs: Relationships with Asian Domestic Pigs and Ryukyu Wild Boars
Activation of Ca 2Ï© -Dependent K Ï© Current by Nordihydroguaiaretic Acid in Porcine Coronary Arterial Smooth Muscle Cells 1
ABSTRACT The effects of nordihydroguaiaretic acid (NDGA), a lipoxygenase inhibitor and an antioxidant, on membrane currents were examined in single smooth muscle cells isolated from porcine coronary artery. Spontaneous transient outward currents (STOCs) recorded at ÏȘ30 mV were markedly enhanced by NDGA (Ő10 M). Pretreatment with caffeine and ryanodine abolished STOCs and reduced NDGA-induced increase in outward current at ÏȘ30 mV by Ïł60%. NDGA showed dual action on an outward current elicited by step depolarization from ÏȘ60 to 0 mV: inhibition and enhancement at concentrations of 3 and Ő10 M, respectively. In the presence of Cd 2Ï© , the inhibition of outward current by NDGA disappeared and the enhancement remained. NDGA inhibited both the voltage-dependent Ca 2Ï© channel current (IC 50 Ï 2.5 M) and the delayed rectifier K Ï© current (IC 50 Ï 9.8 M). The NDGA-induced enhancement of STOCs and outward currents on depolarization was abolished by 100 nM iberiotoxin but was not affected by glibenclamide or apamin. Under current clamp mode, 30 M NDGA significantly hyperpolarized myocytes. The application of lipoxygenase inhibitors (caffeic acid and esculetin), a cyclooxygenase inhibitor (indomethacin), antioxidants (ascorbic acid and erythorbic acid), and structural-related compounds of NDGA (catechol and dopamine) did not enhance K Ï© currents. These results indicate that the opening of the large conductance Ca 2Ï© -dependent K Ï© channel by NDGA, which is independent of its lipoxygenase inhibition or antioxidant effect, results in membrane hyperpolarization
Search for exotic neutrino-electron interactions using solar neutrinos in XMASS-I
We have searched for exotic neutrino-electron interactions that could be
produced by a neutrino millicharge, by a neutrino magnetic moment, or by dark
photons using solar neutrinos in the XMASS-I liquid xenon detector. We observed
no significant signals in 711 days of data. We obtain an upper limit for
neutrino millicharge of 5.410 at 90\% confidence level
assuming all three species of neutrino have common millicharge. We also set
flavor dependent limits assuming the respective neutrino flavor is the only one
carrying a millicharge, for , for , and for .
These limits are the most stringent yet obtained from direct measurements. We
also obtain an upper limit for the neutrino magnetic moment of
1.810 Bohr magnetons. In addition, we obtain upper limits for
the coupling constant of dark photons in the model of
1.310 if the dark photon mass is 1 MeV,
and 8.810 if it is 10 MeV
Monozygotic multiple gestation following in vitro fertilization: analysis of seven cases from Japan
We present a series of monozygous multiple gestations achieved following in vitro fertilization (IVF): one case of monochorionic triplet pregnancy and six cases of dizygotic triplet pregnancy. From September 2000 to December 2006, all patients achieving clinical pregnancy by ART were reviewed (n = 2433). A 37 year-old woman who delivered a healthy singleton after IVF returned two years later for FET, and a single blastocyst was transferred. This also resulted in pregnancy, but TV-USG revealed a single gestational sac with three distinct amniotic sacs, each containing a distinct fetal pole with cardiac activity. This pregnancy was electively terminated at nine weeks' gestation. An additional six cases of dizygotic triplets established after fresh embryo transfer (no ICSI or assisted hatching) are also described. Of these, one resulted in a miscarriage at eight weeks' gestation and five patients have an ongoing pregnancy. This case series suggests the incidence of dizygotic/monochorionic triplets following IVF is approximately 10 times higher than the expected rate in unassisted conceptions, and underscores the importance of a conservative approach to lower the number of embryos at transfer. The role of embryo transfer technique and in vitro culture media in the twinning process requires further study
Consanguinity decreases risk of breast cancer â cervical cancer unaffected
Marriages between third-degree and more distant relatives are common in many parts of the world. Offspring of consanguineous parents have increased morbidity and mortality related to recessive gene disorders. In a population with a high frequency of consanguinity, we examined the frequency of breast cancer (related in part to tumour genes) and cervical cancers (related to virus infection) among offspring of consanguineous and non-consanguineous parents. Study was done prospectively in the United Arab Emirates. Selected were married female citizens, ages 40â65, who attended 12 primary health care clinics for whatever reason. In a face-to-face interview, subjects were asked: (a) about consanguineous marriages in family; (b) if they have or have had breast or cervical cancer; (c) about family history of cancer, cancer screening and other parameters. Tumour diagnosis was confirmed by review of medical records. Of 1750 women invited into study, 1445 (79%) could be used in analysis. Among 579 (40%) women of consanguineous and 866 (60%) of non-consanguineous parents there were 24 and 54 with breast cancer, respectively (RR = 0.66, CI 0.42âââ1.06). In the 40 to 50 age group, breast cancer reported 13 of 446 women of consanguineous and 37 of 633 of non-consanguineous parents (RR = 0.50, Cl 0.27âââ0.93). Cervical cancer had 15 women in consanguineous and 32 in non-consanguineous group (RR = 0.70, Cl 0.38âââ1.28). Number of families with history of breast cancer in consanguineous and non-consanguineous group was 21 and 23, respectively (P = 0.29). The cancer screening rates and other variable values had fairly balanced distribution between the 2 groups. Having consanguineous parents decreases the risk of breast cancer especially in younger women, risk of cervical cancer being unaffected. © 2001 Cancer Research Campaign http://www.bjcancer.co
- âŠ