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The effect of neurotensin on submaximally-stimulated hepatobiliary and pancreatic secretion was studied in 6 healthy subjects. An intravenous infusion of neurotensin 1.4 ± 0.3 pmol/kg/min, designed to reproduce plasma neurotensin immunoreactivity levels within the physiological range, produced a significant increase in pancreatic bicarbonate output. Plasma concentrations of pancreatic polypeptide rose by 83 ± 16 pmol/l and were associated with a small reduction in trypsin, but no significant change in bilirubin outputs. 相似文献
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With more than 40,000 species, Malacostraca is the most diverse crustacean class. Most malacostracans are gonochoristic, but simultaneous hermaphrodites are also known. Tanaidacea is one of two malacostracan orders that includes simultaneously hermaphroditic species; so far, simultaneous hermaphroditism has been confirmed externally and internally in only two tanaidacean species, both in the genus Apseudes (Apseudidae). Here we show, through external and internal morphological observations of fixed specimens, that the apseudid Falsapseudes bowmani is a simultaneous hermaphrodite, making Falsapseudes the second tanaidacean genus in which simultaneous hermaphroditism has been confirmed both externally and internally. In this species, the epistome (a projection on the clypeus) was thick and elongate in large specimens but was thin and spiniform in smaller specimens; the brooding of eggs or embryos was observed only in thin‐epistome individuals, although a pair of ovaries was confirmed in both thick‐ and thin‐epistome individuals. This suggests that individuals with a thick epistome may act as males while also retaining the female reproductive organs. 相似文献
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We isolated 20 anonymous nuclear loci (8556 bp in total) from the Taiwan Hwamei (Garrulax taewanus), an endemic songbird of Taiwan. A panel of nine to 15 individuals with unknown relationship was used to characterize polymorphism of these loci. We identified 46 single nucleotide polymorphic sites (SNPs) in 15 polymorphic loci. Frequency of SNPs was one per every 186 bp in average. Nucleotide diversity, θ, ranged from 0.00054 to 0.00371 per locus. We also tested cross‐species applicability of these loci on 17 species from eight different passerine families. All 20 loci could be successfully amplified (ranged from one to 16 species, mean = 7.9 species). 相似文献
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Abstract. This study describes a technique to record small (1 cm) distance changes or movements occurring in seawater using a simple electronic circuit and miniature ball electrodes. This low-cost technique was designed to directly measure such changes in a broad range of experiments involving small marine invertebrates while minimizing the mechanical loading of the structures of interest. The circuit detects and amplifies small changes in the resistance of seawater between two electrodes as the distance between them varies; these are then converted to voltage changes. After calibrating the output of the device with known distance measurements, it was evaluated using a test organism by monitoring and recording the body flushing behavior of the sea squirt, Styela plicata . Electrodes were sewn to the tunic at the base of the atrial siphon and changes in its diameter were recorded >24-h periods. Using ∼3-cm-tall sea squirts, the distance between the electrodes expanded and contracted with a range of 5.5 mm during rhythmic flushings. Flushes occurred on average every 4.1 min and showed a rapid initial contraction, followed by a slower expansion while refilling. Attaching electrodes to the tunic had little mechanical or behavioral effect; the untouched control specimen had similar flushing rates. The movement monitor circuit is stable, sensitive, and performed well in full-strength seawater experiments where good spatial and high temporal resolution, low inertial loading, and low noise were required. The technique, as shown here, can be used to record a wide range of animal movements and further suggested modifications of the circuit may suit a broad range of other experimental situations. 相似文献
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The arrangement of the musculature and connective tissues of the buccal mass of the coleoid cephalopods Octopus bimaculoides, Sepia officinalis, and Loliguncula brevis was examined using dissection and histology. Serial sections in three mutually perpendicular planes were used to identify the muscles and connective tissues responsible for beak movements and stability and to describe their morphology and fiber trajectories. Four major beak muscles were identified: the anterior, posterior, superior, and lateral mandibular muscles. The anterior, posterior, and superior mandibular muscles connect the upper beak and the lower beak. Although the lateral mandibular muscles originate on the upper beak, they do not connect to the lower beak and instead insert on a connective tissue sheath surrounding the buccal mass. Examination of the fibers of the lateral mandibular muscles reveals that they have the organization of a muscular hydrostat, with muscle fibers oriented in three mutually perpendicular orientations. Although the beaks are capable of complex opening, closing, and shearing movements, they do not contact one another and are instead connected only by the musculature of the buccal mass. Based on the morphological analysis and observations of freshly dissected beaks undergoing the stereotyped bite cycle, the functional role of the beak muscles is hypothesized. The anterior and superior mandibular muscles are likely responsible for beak closing and shearing movements. The posterior mandibular muscle is likely also involved in beak closing, but may act synergistically with the lateral mandibular muscles to open the beaks. The lateral mandibular muscles may use a muscular-hydrostatic mechanism to control the location of the pivot between the beaks and to generate the force required for beak opening. The lack of contact between the beaks and the morphology of the lateral mandibular muscles suggests that the buccal mass of coleoid cephalopods may represent a previously unexamined flexible joint mechanism. The term "muscle articulation" is proposed here to denote the importance of the musculature in the function of such a joint. 相似文献
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Long runs of seasonal rotifer population data allow analysis of seasonal occurrence using mathematical tools. The application of Fourier analysis to a 15 year dataset describes seasonality in simple mathematical terms. This facilitates comparison of population expression with potential population driving variables and provides a basic modelling tool. Results show that annual patterns of occurrence and density have linkages with annual maximum and minimum environmental temperature, although the exact relationships are not clear. 相似文献
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Ziver Sahin Muge Bıcakcıgil Kenan Aksu Sevil Kamali Servet Akar Fatos Onen Omer Karadag Zeynep Ozbalkan Askin Ates Huseyin TE Ozer Vuslat Yilmaz Emire Seyahi Mehmet A Ozturk Ayse Cefle Veli Cobankara A Mesut Onat Ercan Tunc Nursen Düzgün Sibel Z Aydin Neslihan Yilmaz İzzet Fresko Yasar Karaaslan Sedat Kiraz Nurullah Akkoc Murat Inanc Gokhan Keser F Aytul Uyar Haner Direskeneli Güher Saruhan-Direskeneli 《Arthritis research & therapy》2012,14(1):R27-5