alpha-Synuclein locus triplication causes Parkinson's disease     

Singleton AB  Farrer M  Johnson J  Singleton A  Hague S  Kachergus J  Hulihan M  Peuralinna T  Dutra A  Nussbaum R  Lincoln S  Crawley A  Hanson M  Maraganore D  Adler C  Cookson MR  Muenter M  Baptista M  Miller D  Blancato J  Hardy J  Gwinn-Hardy K 《Science (New York, N.Y.)》2003,302(5646):841

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Watching vibrational energy transfer in liquids with atomic spatial resolution     

Wang Z  Pakoulev A  Dlott DD 《Science (New York, N.Y.)》2002,296(5576):2201-2203

Ultrafast spectroscopy was used to study vibrational energy transfer between vibrational reporter groups on different parts of a molecule in a liquid. When OH stretching vibrations of different alcohols were excited by mid-infrared laser pulses, vibrational energy was observed to move through intervening CH2 or CH groups, taking steps up and down in energy, ending up at terminal CH3 groups. For each additional CH2 group in the path between OH and CH3, the time for vibrational energy transfer increased by about 0.4 picosecond.  相似文献   

Martian atmospheric erosion rates     

Barabash S  Fedorov A  Lundin R  Sauvaud JA 《Science (New York, N.Y.)》2007,315(5811):501-503

Mars was once wet but is now dry, and the fate of its ancient carbon dioxide atmosphere is one of the biggest puzzles in martian planetology. We have measured the current loss rate due to the solar wind interaction for different species: Q(O+) = 1.6.10(23) per second = 4 grams per second (g s(-1)), Q(O+2) = 1.5.10(23) s(-1) = 8 g s(-1), and Q(CO+2) = 8.10(22) s(-1) = 6 g s(-1) in the energy range of 30 to 30,000 electron volts per charge. These rates can be propagated backward over a period of 3.5 billion years, resulting in the total removal of 0.2 to 4 millibar of carbon dioxide and a few centimeters of water. The escape rate is low, and thus one has to continue searching for water reservoirs and carbon dioxide stores on or beneath the planetary surface and investigate other escape channels.  相似文献   

Controlled phase shifts with a single quantum dot     

Fushman I  Englund D  Faraon A  Stoltz N  Petroff P  Vuckovic J 《Science (New York, N.Y.)》2008,320(5877):769-772

Optical nonlinearities enable photon-photon interaction and lie at the heart of several proposals for quantum information processing, quantum nondemolition measurements of photons, and optical signal processing. To date, the largest nonlinearities have been realized with single atoms and atomic ensembles. We show that a single quantum dot coupled to a photonic crystal nanocavity can facilitate controlled phase and amplitude modulation between two modes of light at the single-photon level. At larger control powers, we observed phase shifts up to pi/4 and amplitude modulation up to 50%. This was accomplished by varying the photon number in the control beam at a wavelength that was the same as that of the signal, or at a wavelength that was detuned by several quantum dot linewidths from the signal. Our results present a step toward quantum logic devices and quantum nondemolition measurements on a chip.  相似文献   

Destroyers by the pound?     

Lincoln TL 《Science (New York, N.Y.)》1985,230(4721):8

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Effects of Temperature on Performance Characteristics and the Cortisol Stress Response of Surubim Pseudoplatystoma sp.   总被引：1，自引：0，他引：1  

Luciene C.  Lima Lincoln P.  Ribeiro Jeffrey A.  Malison  Terence P.  Barry  James A.  Held 《Journal of the World Aquaculture Society》2006,37(1):89-95

Three experiments were conducted in flow‐through tanks at 24, 27 and 30 C to evaluate growth, food conversion, morbidity, survival, and the cortisol stress response of surubim Pseudoplatystoma sp. at different temperatures. In Experiment 1, fish (mean initial weight, 33.3 ± 7.2 g) reared at 27 and 30 C for 60 d grew significantly faster than fish reared at 24 C (P < 0.05). Fish at the lowest temperature showed the poorest feed conversion ratio (FCR, 5:1), while fish at 27 and 30 C had FCRs of 2.5:1 and 3.5:1, respectively. Mortality and morbidity rates were inversely proportional to the temperatures tested. In Experiment 2, serum cortisol levels following an acute handling stressor peaked at 30 min after stress, returned to near‐resting levels at 1 h after stress, and completely returned to resting levels at 3 h after stress in fish at all temperatures tested. Peak serum cortisol levels were higher in fish at 30 C (321.1 ± 38.8 ng/mL) than those in fish at 27 and 24 C (143.3 ± 37.4 ng/mL and 104.2 ± 37.2 ng/mL, respectively). In Experiment 3, fish (mean initial weight, 67 ± 8.58 g) reared at 27 C for 137 d grew significantly faster than fish at 30 and 24 C. Virtually, all fish reared in 30 C had some sign of morbidity (skin lesions and fin abrasion) compared to only a small percentage of fish in the other two temperatures. Again, the highest cortisol peak level was measured in fish reared at 30 C (117.6 ± 16.7 ng/mL), as compared to fish at 24 and 27 C (99.2 ± 15.5 ng/mL and 80.2 ± 12.8 ng/mL, respectively). Our findings indicate that the optimum temperature for rearing surubim in tanks is 27 C. At 30 C, these fish may suffer from stress, as suggested by the elevated peak of cortisol and morbidity and mortality rates. The relatively rapid cortisol stress response of surubim suggests that they may be more tolerant to handling stressors than other fish species.  相似文献   

Susceptibility of imidacloprid-resistant Colorado potato beetles to non-neonicotinoid insecticides in the laboratory and field trials     

Andrei Alyokhin  Galen Dively  Megan Patterson  Matthew Mahoney  David Rogers  John Wollam 《American Journal of Potato Research》2006,83(6):485-494

Repeated use of neonicotinoid insecticides has resulted in the first reported cases of Colorado potato beetle (Leptinotarsa decemlineata (Say)) resistance to imidacloprid. In the laboratory we determined susceptibility of the imidacloprid-resistant Colorado potato beetles from a population in Southern Maine to other insecticides currently registered for use on potato. This population was about 30-fold resistant to imidacloprid and could not be effectively controlled by its applications. Control mortality was significantly higher for the imidacloprid-resistant larvae than for the susceptible larvae, suggesting that fitness disadvantages may be associated with the resistance trait. Resistant larvae exhibited significantly less mortality than susceptible larvae when exposed to cyfluthrin, carbaryl, azinphosmethyl, and methamidophos. Their susceptibility to oxamyl was also somewhat reduced, although it did provide nearly 100% mortality at the highest concentration tested. Disulfoton was highly toxic to the resistant larvae. Oxamyl killed about 40% of the adults in greenhouse assays with potted potato plants, altered their feeding behavior (fewer adults up on plants), and reduced defoliation by more than 90%. Disulfoton was not lethal to adults, but significantly suppressed their feeding. In field trials with the resistant population, oxamyl and imidacloprid + spinosad provided the best beetle control. Novaluron had no detectable effect on beetle densities. There was little difference between the plots treated with imidacloprid or thiamethoxam and the untreated control. Our results suggest that insecticide rotation may be a valuable option for managing imidacloprid-resistant Colorado potato beetle populations. We also had a good consistency between the results of the Petri dish, greenhouse, and field experiments, indicating that screening under laboratory confinement may be useful when developing initial recommendations to potato growers in areas affected by resistance to neonicotinoids.  相似文献   

An unusual case of a mature teratoma on the left perineal region of a young cat: surgical treatment and pathological description     

Ciprian Andrei Ober  Marian Taulescu  Liviu Oana  Lucia Bel  Cornel C?toi  Laura F?rcas  Cosmin Pestean 《Acta veterinaria Scandinavica》2013,55(1):51

A 10-month-old intact male cat with a clinical history of a large mass in the left perineal region was submitted to the surgery department. The mass had reportedly been present as a small swelling after birth. Cytological evaluation using a fine-needle aspirate showed eosinophilic keratinaceous debris, and was not convincing for the definitive diagnosis. Complete surgical excision was performed. Postoperative function and aesthetics were excellent. Based on gross and histological features the definitive diagnosis of the tumor was mature teratoma with ectodermal and endodermal components. After a follow-up period of 4 months, no signs of recurrence were evident. Surgical excision of the teratoma in our case was considered curative. A perineal location has not been previously reported in the cat and should be considered a rare condition in this species.  相似文献   

Dynamic Oryza Genomes: Repetitive DNA Sequences as Genome Modeling Agents     

Navdeep Gill  Phillip SanMiguel  Braham Deep Singh Dhillon  Brian Abernathy  HyeRan Kim  Lincoln Stein  Doreen Ware  Rod Wing  Scott A. Jackson 《Rice》2010,3(4):251-269

Repetitive sequences, primarily transposable elements form an indispensable part of eukaryotic genomes. However, little is known about how these sequences originate, evolve and function in context of a genome. In an attempt to address this question, we performed a comparative analysis of repetitive DNA sequences in the genus Oryza, representing ~15 million years of evolution. Both Class I and Class II transposable elements, through their expansion, loss and movement in the genome, were found to influence genome size variation in this genus. We identified 38 LTRretrotransposon families that are present in 1,500 or more copies throughout Oryza, and many are preferentially amplified in specific lineages. The data presented here, besides furthering our understanding of genome organization in the genus Oryza, will aid in the assembly, annotation and analysis of genomic data, as part of the future genome sequencing projects of O. sativa wild relatives.  相似文献   

Identification of the honey bee swarming process by analysing the time course of hive vibrations     

Martin Bencsik  Joseph BencsikMichael Baxter  Andrei LucianJulien Romieu  Mathias Millet 《Computers and Electronics in Agriculture》2011,76(1):44-50

Honey bees live in groups of approximately 40,000 individuals and go through their reproductive cycle by the swarming process, during which the old queen leaves the nest with numerous workers and drones to form a new colony. In the spring time, many clues can be seen in the hive, which sometimes demonstrate the proximity to swarming, such as the presence of more or less mature queen cells. In spite of this the actual date and time of swarming cannot be predicted accurately, as we still need to better understand this important physiological event. Here we show that, by means of a simple transducer secured to the outside wall of a hive, a set of statistically independent instantaneous vibration signals of honey bees can be identified and monitored in time using a fully automated and non-invasive method. The amplitudes of the independent signals form a multi-dimensional time-varying vector which was logged continuously for eight months. We found that combined with specifically tailored weighting factors, this vector provides a signature highly specific to the swarming process and its build up in time, thereby shedding new light on it and allowing its prediction several days in advance. The output of our monitoring method could be used to provide other signatures highly specific to other physiological processes in honey bees, and applied to better understand health issues recently encountered by pollinators.  相似文献