Determination of lithium isotopic composition by thermal ionization mass spectrometry

A mass spectrometric method has been proposed for the determination of the isotopic composition of lithium. It is based upon thermal ionization of LiOH loaded onto a single SiO2-coated Re filament. By this method, stable emissions of Li+ ion have been achieved for an extended period of time. The proposed method is capable of analyzing trace quantities (approximately 40 ng) of Li in the presence of sodium with an uncertainty of +/-0.000 25 (two standard deviations of the mean).     

Is visual imagery really visual? Overlooked evidence from neuropsychology.

Does visual imagery engage some of the same representations used in visual perception? The evidence collected by cognitive psychologists in support of this claim has been challenged by three types of alternative explanation: Tacit knowledge, according to which subjects use nonvisual representations to simulate the use of visual representations during imagery tasks, guided by their tacit knowledge of their visual systems; experimenter expectancy, according to which the data implicating shared representations for imagery and perception is an artifact of experimenter expectancies; and nonvisual spatial representation, according to which imagery representations are partially similar to visual representations in the way they code spatial relations but are not visual representations. This article reviews previously overlooked neuropsychological evidence on the relation between imagery and perception, and discusses its relative immunity to the foregoing alternative explanations. This evidence includes electrophysiological and cerebral blood flow studies localizing brain activity during imagery to cortical visual areas, and parallels between the selective effects of brain damage on visual perception and imagery. Because these findings cannot be accounted for in the same way as traditional cognitive data using the alternative explanations listed earlier, they can play a decisive role in answering the title question. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Laser in situ keratomileusis: literature review of a developing technique

We reviewed papers published in peer-reviewed journals describing techniques and results of laser in situ keratomileusis (LASIK) and summarized the instruments used, nomograms, preoperative and postoperative refractions, predictability, outcome, safety, and complications. We performed a similar review of abstracts published in the abstract books of the 1996 meeting of the International Society of Refractive Surgery, the 1997 meeting of the Association for Research in Vision and Ophthalmology, and the 1997 meeting of the American Society of Cataract and Refractive Surgery. The number of LASIK and photorefractive keratectomy (PRK) patients described in the abstracts were sorted by city. Mean weighted latitudes were calculated and compared for each procedure. The mean preoperative refraction in the papers was -12.59 diopters (D), which was statistically higher than that in the abstracts, -8.71 D (P < .001), and the mean postoperative refraction, -1.10 and + 0.93 D, respectively. The mean percentage of cases within +/- 1.00 D was 67.0% in the papers and 82.5% in the abstracts. Uncorrected visual acuity (UCVA) of 20/40 or better was achieved in 49.2% of eyes in the papers and 83.2% of those in the abstracts; a UCVA of 20/20 or better was achieved in 22.0 and 56.6%, respectively. The portion of eyes that lost two or more lines of best corrected visual was 8.0% in the papers and 0.9% in the abstracts. Complications in the papers included irregular flap (4.0%), incomplete cut (2.5%), free cap (4.9%), perforated lenticule (2.6%), short flap (3.0%), sliding flap (1.4%), interface debris (6.8%), central island (5.3%), decentration (4.7%), epithelial ingrowth (4.3%), induced astigmatism (5.1%), wrinkles (5.9%), haze (8.7%), night vision problems (14.0%), and reoperation (8.2%), Mean latitude for LASIK cases (27.00 degrees +/- 13.73 [SD] was significantly lower than that for PRK cases (42.85 +/- 11.7 degrees). Visual outcomes of LASIK surgery show significant improvements when recent abstracts are compared with published papers. This may reflect continued improvement in the surgical techniques, surgeons' skills, and visual outcomes.     

The influence of sad mood on cognition.

Neuroimaging has identified an overlapping network of brain regions whose activity is modulated by mood and cognition. Studies of depressed individuals have shown changes in perception, attention, memory, and executive functions. This suggests that mood has a pervasive effect on cognition. Direct evidence of the effect of sad mood on cognition is surprisingly limited, however. Published studies have generally addressed a single cognitive ability per study because the fleeting nature of laboratory-induced mood precludes extended testing, and robust findings are limited to mood effects on memory for emotional stimuli. In this study, sad mood was induced and prolonged, enabling the effects of mood to be assessed for an array of abilities, including those that share neural substrates with sad mood and those affected by depression. Sad mood affected memory for emotional words and facial emotion recognition, but not the other processes measured, with a significant nonuniformity of effect over tasks. These results are consistent with circumscribed effects of sad mood on certain emotion-related cognitive processes, but not on cognition more generally. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Parallel Proximal Splitting Method for Disparity Estimation from Multicomponent Images Under Illumination Variation

Proximal splitting algorithms play a central role in finding the numerical solution of convex optimization problems. This paper addresses the problem of stereo matching of multi-component images by jointly estimating the disparity and the illumination variation. The global formulation being non-convex, the problem is addressed by solving a sequence of convex relaxations. Each convex relaxation is non trivial and involves many constraints aiming at imposing some regularity on the solution. Experiments demonstrate that the method is efficient and provides better results compared with other approaches.     

Crop yield prediction from remotely sensed vegetation indices and primary productivity in arid and semi-arid lands

Global demands for biomass and arable lands are expected to double in the next 35 years. Scarcity of water resources in arid and semi-arid areas poses a serious threat to their agricultural productivity and hence their food security. In this study, we examine whether crop yields can be predicted from remotely sensed vegetation indices and remotely sensed estimates of primary productivity. Spatial relationships between remotely sensed enhanced vegetation index (EVI), net photosynthesis (P_Net), and gross and net primary production (GPP and NPP, respectively) in irrigated semi-arid and arid agro-ecosystems since the beginning of the century are analysed. The conflict-affected country of Syria is selected as the case study. Relationships between EVI and crop yield are investigated in an effort to enhance food production estimates in affected areas outside governmental jurisdictions. Estimates of NPP derived from reported irrigated agriculture crop data in a semi-arid and an arid zone are compared to remotely sensed NPP in a geospatial environment. Results show that winter crop yields are correlated with spring GPP in semi-arid zones of the study area (R² = 0.85). Summer crop yield can be predicted from either cumulative summer EVI (R² = 0.77) or P_Net in most zones. Where fully irrigated fields are surrounded by hyper-arid landscape, summer P_Net was negative in all instances and EVI was inversely correlated with yield. NPP from crops was much higher (290 gC m^?2 year^?1) in those regions than MOD17 NPP (70 gC m^–2), where 1.0 g of carbon is equivalent to 2.2 g of oven-dry organic matter (= 45% carbon by weight). The gap was less in semi-arid zones (2–39% difference). Overall crop-derived NPP for the period 2000–2013 was 322 versus 300 gC m^–2 for that remotely sensed within the cropped zones of the political units. The results of this study are crucial to derive accurate estimates of irrigated agriculture productivity and to study the effect of the latter on net ecosystem carbon storage.     

Intramuscular fatty acid profile of longissimus dorsi and semitendinosus muscle from Kundi steers fed on pasture with cottonseed cake supplement

The present study was accomplished to evaluate the intramuscular fatty acid (FA) composition of different muscles taken from Kundi steers (n = 15), which were approximately 24 months old, fed on a cottonseed cake supplement, and were made to graze on alfalfa pasture for 95 days prior to slaughter. The samples were taken from longissimus dorsi region (loin and ribeye portion) and distal region of semitendinosus muscle for intramuscular FA analysis. Saturated FA, comprising 49.48–52.09% of total FA composition, in all the muscles were studied. Ribeye portion of longissimus dorsi muscle contain relatively higher (P > 0.05) amount of trans FA (3.37%) as compared with loin portion of longissimus dorsi muscle (3.1%) and distal region of semitendinosus muscle (2.84%). The sum of monounsaturated FA in all the muscles studied was estimated in the range of 32.21–34.64%, while polyunsaturated FA contribute 11.39–12.39% of total FA. The mean conjugated linoleic acid was found to be 0.28, 0.35 and 0.41 in ribeye and loin portion of longissimus dorsi muscle and distal region of semitendinosus muscle, respectively.     

Measurement of anthocyanins and other phytochemicals in purple wheat

The major anthocyanin composition of normal purple wheat and heat stressed purple wheat were measured using HPLC, LC–MS/MS and the pH differential method. The lignan secoisolariciresinol diglucoside (SDG) and melatonin content were also measured. Total anthocyanin profile of normal purple wheat (491.3 mg/kg) was significantly (P < 0.05) lower than that of the heat stressed purple wheat (522.7 mg/kg). Thirteen major anthocyanins were isolated and cyanidin 3-glucoside was the predominant anthocyanin in purple wheat. Using the pH differential method, the total anthocyanin content of normal (500.6 mg/kg) and heat stressed (526.0 mg/kg) purple wheat were similar to those observed using HPLC. The SDG content of normal and heat stressed purple wheat were 770 and 520 μg/kg, while melatonin content was 4 and 2 μg/kg, respectively. The presence of SDG and melatonin in addition to anthocyanins may contribute to the health benefits associated with consumption of coloured cereal grains.     

Volatile compounds as potential defective coffee beans’ markers

Although Brazil is the largest raw coffee producer and exporter in the world, a large amount of its Arabica coffee production is considered inappropriate for exportation. This by-product of coffee industry is called PVA due to the presence of black (P), green (V) and sour (A) defective beans, which are known to contribute considerably for cup quality decrease. Data on the volatile composition of Brazilian defective coffee beans are scarce. In this study, we evaluated the volatile composition of defective coffee beans (two lots) compared to good quality beans from the respective lots. Potential defective beans’ markers were identified. In the raw samples, 2-methylpyrazine and 2-furylmethanol acetate were identified only in black-immature beans and butyrolactone only in sour beans, while benzaldehyde and 2,3,5,6-tetramethylpyrazine showed to be potential markers of defective beans in general. In the roasted PVA beans, pyrazine, 2,3-butanediol meso, 2-methyl-5-(1-propenyl)pyrazine, hexanoic acid, 4-ethyl-guayacol and isopropyl p-cresol sulfide also showed to be potential defective coffee beans’ markers.